Class JTS 23 Book -K 7 Gopyii^htl^° ^■^9i #3^^ 5^£^-rf^, i^ THE CUPOLA FURNACE THE CUPOLA FURNACE A PRACTICAL TREATISE ON THE CONSTRUCTION AND MANAGEMENT OF FOUNDRY CUPOLAS: COMPRISING IMPROVEMENTS IN CUPOLAS AND METHODS OF THEIR CONSTRUCTION AND MANAGE- MENT; TUYERES; MODERN CUPOLAS; CUPOLA FUELS; FLUXING OF IRON; GETTING UP CUPOIA STOCK; RUNNING A CONTINUOUS STREAM; SCIENTIFICALLY DESIGNED CUPOLAS; SPARK-CATCHING DEVICES; BLAST-PIPES AND BLAST: BLOWERS; FOUNDRY TRAM RAIL, ETC., ETC. BY EDWARD KIRK, PRACTICAL MOULDER AND MELTER, CONSULTING EXPERT IN MELTING. Author of " The Fouvding of Metals" and of Numerous Paf-ers on Cupola Practice. ILLUSTRATED BY ONE HUNDRED AND SIX ENGRAVINGS. THIRD THOROUGHLY REVISED AND PARTLY RE-WRITTEN EDITrON. PHILADELPHIA : HENRY CAREY BAIRD & CO., INDUSTRIAL PUBLISHERS, BOOKSELLERS AND IMPORTERS, 810 Walnut Street. LONDON : E. & F. N. SPON, Ltd., 57, Haymarket, S. W. 1910. "^.1 Copyright, 1910, BY EDWARD KIRK. ^ Printed by the WICKERSHAM PRINTING COMPANY, 111-117 East Chestnut f-treet, Lancaster, Pa., U. S. A. ^QlA2li8d24 PREFACE TO THE THIRD EDITION. The second edition of The Cupola Furnace having been for some time exhausted, while the demand for the book con- tinues unabated ; and urgent requests being constantly received from foundrymen for additional information in this important department of the industry are the inducements which have led to the preparation of this new and revised issue. This, the third edition, has been greatly improved by a re- arrangement of chapters and a more appropriate classification of subjects. Its scope and usefulness for the particular branch of business for which it is intended, have been much extended by replacing, with entirely new and up-to-date matter, the sec- tions relating to foundry irons, foundry chemistry and other subjects, which have been omitted because they do not directly pertain to cupola manipulation. The new matter, it may be stated, comprises about 200 pages and includes instructive, illustrated details of cupola accessories and cupola manage- ment. Many founders are to-day in experimental work going over the same ground that has been exploited for years, and in order that they may learn what has already been done in this direction, and thus save themselves unnecessary expense, it has been deemed advisable to describe and illustrate a number of scientifically designed cupolas and tuyere-arrangements of the past. It is confidently believed that a careful study of the follow- ing pages can hardly fail to arouse in the founder, the foreman, and the melter, a realization of the far-reaching importance of an intelligent system of cupola practice and that only by, and through, such a system can be obtained, at a minimum cost, (v) vi PREFACE TO THE THIRD EDITION. an iron indicated by the quality of the iron melted and pos- sessing the properties required for the work to be cast. In conclusion, it only needs to be added, that as is the cus- tom of the publishers, in all cases, they have provided the work with a copious table of contents as well as a very full index, which will render reference to any subject in it, at once, prompt, easy and satisfactory. Edward Kirk. Philadelphia, August, 1910. CONTENTS. CHAPTER I. The Cupola Furnace. PAGE Advantages of the cupola furnace for foundry work; Quantity of fuel required for melting iron in various kinds of furnaces; Attempts to decrease the amount of fuel consumed in a cupola by utilizing the waste he&t 1 Description of the cupola furnace; Forms and sizes of cupolas; Founda- tion of a large cupola .......... 2 Advantage of iron supports over brick work; Height of the bottom of the cupola; Pit beneath the cupola ....... 3 Bottom plate; Bottom doors; Support of the doors; Various devices for holding the doos in place; Construction of the casings ... 4 Stack casing; Construction of the stack; Tuyere holes . . • . 5 Location of the charging door and its construction; Lining of the casing and materials used for it . . 6 The scaffold and its location; Size of the scaffold 7 CHAPTER IL Improvements in Cupof.as. Type of the first cupola furnaces used in this country, and mode of con- structing them; Cupolas in the foundry of Chas. Reeder & Sons, Bal- timore, Md 8 Construction of these cupolas 9 Objection to the draw-front cupola 10 First use of the drop bottom; General mode of building cupolas . .11 Supply of blast; Location of tuyeres 12 Cause of slow melting of old-fashioned cupolas; Heights of cupolas; Boiler-plate casings for both cupola and stack ..... 13 Increase in the size of tuyeres; Lowering of the tuyeres to from 4 to 10 inches above the bottom; Introduction of the Mackenzie cupola . 14 Abandonment of the old theory of driving blast to the center of the cupola by force of the blower and small tuj-eres; Introduction of cast iron tuyere boxes; Objectionable features of the Mackenzie cupola . 15 Introduction of the Truesdale cupola; The Lawrence cupola . .16 (Vii) Vin CONTENTS PAGE The Pevie cupola; The Dougherty tuyere ...... 17 Introduction of the Colliau plain round cupola, and its complete failure. 18 Application of the system of tapping slag to cupolas; Change in the form of cupola supports, bottom doors, air chambers; Previous use of the double row of tuyeres ....•..,. 19 Advantage of the double row of tuyeres 20 Return to the plain round cupola of forty years ago . . . .21 CHAPTER III. Constructing a Cupola. Proper location of a cupola; The scaffold . . • 22 Conveyance of coal or coke to the scaffold; Cupola foundation and its construction , .... 23 Prevention of uneven settling and breaking of the bottom; Brick walls for the support of a cupola; Best supports for a cupola . . .24 Height of cupola bottom; Provision for the removal of the dump; Bot- tom doors ............ 25 Devices for raising the bottom doors ....... 26 Casing; Material for the casing or shell of the modern cupola and stack; Strain upon the casing 27 Contraction of the stack; Prevention of sparks; What constitutes the height of a cupola; Utilization of the waste heat 28 Table giving the approximate height and sizes of doors for cupolas of different diameters; Charging door; Air chamber . . . .29 Construction of the air chamber when placed inside the casing, and when placed upon the outside of the shell; Objection to the round or overhead air chamber .......... 30 Admission of blast to the air chamber; Location and arrangement of the air chamber when the tuyeres are placed high; Tap hole . . .31 Arrangement when two tap holes are required; The spout and its con- struction 32 Tapping slag; Location of the slag-hole 33 Tuyeres; Number of tuyeres for small cupolas; Size of combined tuyere area; Tuyere boxes or casings 34 Height at which tuyeres are placed in cupolas; Objection to high tuyeres ............. 35 Two or more rows of tuyeres; Arrangement of a large number of tuyeres; Area of the rows; Increase in the melting capacity with two or three rows of tuyeres 36 Lining; Materials for lining the casing; Grouting or mortar for laying up a lining; Manner of laying the brick ...... 37 Thickness of cupola linings; Stack lining 38 Arrangement of brackets; Preference by many of angle iron to brackets; Mode of putting in angle irons 39 CONTENTS. IX PAGE Reduction of the lining by burning out; Settling of the lining; Mode of reducing the size and weight of the bottom doors and preventing the casing from rusting off at the bottom ....... 40 Prevention of the absorption of moisture into the lining; Illustration of the triangular-shaped tuyere in position in the lining; Form of bottom plates; Fire-proof scaffolds 41 Exposure of the scaflFold and its supports to fire; Devices to make scaf- folds fire-proof 42 Novel plan of construction of a scaffold and cupola house in Detroit, Mich.; Best and safest scaffolds 43 Cupola scaffolds in the foundries of Gould & Eberhardt, Newark, N. J., and of The Straight Line Engine Company, Syracuse, N. Y. . . 44 CHAPTER IV. CupoivA Tuyeres. Mode of supplying the cupola furnace with air; Admission of the air through tuyeres or tuyere holes; Former and present melting capacity of a cupola; Epidemics of tuyere invention ...... 45 The round tuyere; Arrangement of round tuyeres in the old-fashioned cast-iron stave cupola .......... 46 Oval tuyere; Expanded tuyere ......... 47 Doherty tuyere ............ 48 Sheet blast tuyere; Mackenzie tuyere ....... 49 Blakeney tuyere . . . . . . . . . . . . 50 Horizontal and vertical slot tuyere ........ 51 Reversed X-^uyere; Truesdale reducing tuyere . . . . .52 Lawrence reducing tuyere .......... 53 Triangular tuyere; Results of melting with this tuyere obtained by The Magee Furnace Company, Boston, Mass.; Water tuyere . . .54 Colliau tuyere; Whiting tuyere; Chenney tuyere 56 The double tuyere; Mode of placing the tuyeres in Ireland's cupola; Claims for the double tuyere ......... 57 Consumption of fuel in a double tuyere cupola; Three rows of tuyeres; Cupola constructed by Abendroth Bros., Port Chester, N. Y. . . 58 Theory of producing heat by consuming the escaping gases from the combustion of fuel; Greiner tuyere . . . . . . .59 Adjustable tuyeres; Cupola of the Pennsylvania Diamond Drill and Manufacturing Co., Birdsboro, Penna 60 Bottom tuyeres 61 Mode of covering the mouth of a bottom tuyere 62 Early use of the bottom tuyere; Bottom tuyere patented by B. H. Hib- ler; Thomas D. West on the bottom tuyere ...... 63 Size of tuyeres; Mistake made by foundrymen in regard to the size of tuyeres; Tuyere of the old-fashioned cupola . ..... 64 X CONTENTS. PAGE Size of the combined tuyere area of a cupola; Height of tuyere; Great difference of opinion on this subject <>'T Experiments with tuyeres at various distances above the sand bottom; Experiment to soften hard iron by bringing the molten metal in con- tact with charcoal; Reason given in favor of high tuyeres . tjii Tuyeres in stove foundries; Location of tuyeres in smaller cupolas . (57 Tuyeres in machine and jobbing foundry cupolas, and in cupolas for heavy work . . . . . . . . • ■ • . HS Number of tuyeres; Objection to the use of only one tuyere; Two tuyeres sufficient for the largest cupola in use 69 Arrangement of a double row of tu\eres; Sliape of tuyeres . . .70 Tuyeres to improve the quality of iron; Tuyere boxes . .71 New tuyeres; Causes of success and of failure; Tuyeres not the only factor in successful cupola practice 72 The Watt cupola tuyeres 73 The Zippier tuyere; The Kuoeppel tuyere 75 CHAPTER V. Cupola Management. Necessity of learning the peculiarities in the working of a cupola; A cupola cannot be run by any given rule or set of rules; Drying the lining ....•• ......'' Drying a backing or filling between the casing and lining; Putting up the doors; Devices for raising the doors into place 78 Support of double doors; Sizes of props to support the bottom . 79 Ring attachment to the prop; Superstition of older melters regarding the prop; Dropping the doors; Modes of releasing the prop . . SO Sand bottom; Sand employed for this purpose. Objection to clay sands and other sands; Sand which makes the very best kind of bottom . 81 Wetting the bottom sand; Bringing the sand into the cupola . . . 82 Cause of leakage in the sand bottom Sr! Boiling of iron due to a wet bottom; Pitch or slope of the bottom . . 84 Effect of a high pitch; Change in the action of the iron at the spout by the pitch of the bottom; How the bottom should be made . . .85 Slope of the bottom in cupolas with two tap holes; Spout; Spout lining material ^^ Effect of the use of too much clay or too much sand in the lining; Mode of making up the spout lining ^7 Building up the sides of the lining; Place of the greatest strain upon the spout lining ^^ Proper shape of the spout lining; Cause of pools of iron forming in the spout; Removal of slag from the sprut 89 Front; Material used for putting in the front; Mode of putting in the front 90 CONTENTS. XI PAGE Effect of making the front material too wet; Troubles due to poor front material ............. 91 Sizes of tap holes; Locating the tap holes ....... 92 Slag hole 93 Slag hole front; Chilling of slag in the tap hole . . . .94 Lighting up; Mode of placing the wood and shavings in the cupola; Putting in the bed fuel 9.S Effect of carelessness in arranging the wood and lighting up . . . 96 New method of lighting up; The Buckeye Heater or oil torch . . 97 The bed; The melting point or melting zone in a cupola; Determina- tion of the exact location of the melting zone; Necessity of discover- ing the melting-point in order to do good melting .... 98 To find the melting-point .......... 99 Cause of trouble in melting after a cupola has been newly lined; Fuel required for a bed in cupolas of different diameters; Charging; Old way of loading or putting the fuel and iron into a cupola . . 109 Modern way of stocking a cupola; Correct theory of melting iron in a cupola; Practical woiking of a cupola upon this theory . . . lUl Effect of too heavy charges of iron and of too heavy charges of fuel; Variations in the weight of the first charge of iron in proportion to the weight of the bed 102 Variations in the per cent, of iron to fuel; Placing the charges . . 103 Mode of placing the pieces of pig or other iron; Distribution of the charge of fuel; First step in mixing irons when melted in a cupola . 104 Placing the pig iron when melting with remelt scrap .... 105 Charging whtn melting old scrap and pig; Charging additional iron; Bad charging as a cause of poor melting ...... lOH Charging flux; On what the quantity of flux depends .... 107 Blast; The old and modern ways of giving blast to the cupola; Blast phenomena; Melting .......... lOH When melting I egins in a cupola; Difference of opinion as to the time of charging the iron before the blast is put on ..... 109 Best way to put on the blast; Chilling and hardening of the first iron; Running off a heat without stopping in; Mode of reducing the size of the tap hole 110 No advantage in holding molten iron in a cupola to keep it hot; Proper management of hand-ladle work ........ Ill Indication of how the cupola is melting by the flow of iron from the tap hole; Poking the tuyeres ......... 112 Fuel; Amount of fuel required in theory and in practice . .113 Necessity of keeping an accurate account of the amount of iron melted; Chief olject of mtlting in a cupola . . . . . . .114 The old story of "not enough blast; " Necessity of an even volume of blast; Tapping bars; Shapes and sizes of tapping bars . . . . 115 Steel bar for cutting away the bod before tapping; Bod sticks . .116 XU CONTENTS. PAGE Combination stick; Objection to this stick; Number of bod sticks for each cupola; Bod material; Importance of the material of which the bod is composed 117 Loams for bods; Mixture for a good bod; Bod for small cupolas . .118 Qualities of a good bod; Tapping and stopping in; Mode of making the bod 119 How to make the tap; Mode of stopping in 120 The skill of the melter seen at the tap hole; Uneven melting the fault of the melter 121 Dumping; Removal of the props; Starting the sand bottom . . . 122 Bridging over in small cupolas above the tuyeres, and mode of remov- ing the bridge; Various methods of handling the dump . . . 123 Removing the dump, and various devices for this purpose; Breaking up and picking it over; Different ways of recovering the iron from the dump 124 Chipping out; Theory of some melters to prevent iron from running into the tuyeres; Objection to this theory 125 Cupola picks; Daubing; Materials for this purpose 126 Soaking fire clay ........... 127 Amount of sand required for mixing with the clay; No advantage in using a poor cheap daubing; Shaping the lining; Object of applying daubing . . 128 Mode of making new linings; Chipping off cinder and slag that adhere to the lining over the tuyeres; No necessity for filling in the lining at the melting zone and making it perfectly straight .... 12!» Objections to sudden offsets or projections; Thickness of the daubing; Sectional view of a cupola illustrating effect of excessive daubing . 13(( Shaping the lining of the boshed cupola l;i2 Special directions required for shaping and keeping up the lining of patent and odd shaped cupolas; Relining and repairing; Thickness of the lining; Location of the greatest wear of the lining; Destruction of the lining at and below the tuyeres 13;^ Length of time a cupola lining will last; Burning away of the lining; Thickness of lining required to protect the casing; Repairing the lining at the melting zone 134 Repairing a lining with a split brick; Mode of making a split brick; An excellent daubing material . . . . . . , . .135 CHAPTER VI. Modern Cupoi.as. Interesting fact in connection with modern cupolas; Importance of high cupolas for fast and economical melting; CoUiau cupolas . . 137 Standard CoUiau cupola furnace ... .... 138 The Newten cupola 141 CONTENTS. ' xiii PAGE Paxson Colliau cupola 144 Indestructible wire screen charging door of this furnace . . . . 147 The Whiting cupola 148 The E. J. E. cupola 150 Points of special merit of the E. J. E. cupola 151 Calumet cupola ............ 15:i CHAPTER VII. Largk Cupolas. The Homestead large cupolas of the Carnegie Steel Works; Dimensions of these cupolas . . . . . . . . . . . 15<> Shape of lining of very large cupolas; The McShane large cupola . . 157 Non-success of this cupola and causes of uneven melting in it . . 158 The Thos. D. West large cupola; Trouble with the center blast of this cupola 159 Plan of making large cupolas melt at the center; How a diameter of 55 to 60 inches at the tuyeres may readily be obtained in cupolas of larger size without danger of bridging or hanging up .... 160 Advantages and disadvantages of large cupolas . . . . .161 CHAPTER VIII. Smali. Cupolas. General use of small cupolas in the early days of foundry practice in this country; Gradual increase in the size of cupolas .... 1G4 Necessity of testing a new brand of mixture of iron; Value of the small cupola for various purposes ......... 165 Swivel cupolas; Small cupola in use at the foundry of Charles Spangler, Allentown, Pa 166 A portable small cupola .......... 168 A cheap small movable cupola . . . . . . . . .170 Management of a small cupola; The Keep sectional cupola . . . 171 Advantages claimed for this cupola . . . . . . . . 1 73 Stationary bottom cupola 174 Small cupolas for bedstead work . . . . . . . .175 Cupola on wheels; Paxson truck and track cupola . . . . .177 Small cupolas of Europe; Smaller cupolas used throughout the mid- lands of Great Britain and in the small foundries of Belgium and France 178 XIV CONTENTS. PAGE CHAPTER IX. Examples of Bad Melting. Necessity of knowing causes of poor melting; Trouble with the cupolas at the stove foundry of Perry & Co., Sing Sing, N. Y. . . . IS] Cause for the trouble 182 Sectional views of linings out of shape ....... 183 Remedy for the troubles .......... 188 Bad melting at a West Troy stove works; Visit to the foundry of Daniel E. Paris & Co., West Troy, N. Y.; Inspection of the foundry with a view of locating the trouble ......... 19li Trouble due to the use of too much fuel ....... 10] Experiment of running the cupola with less fuel; Objection of the melter to the experiment ......... 191' Result of the experiment 19o Heats with a still further reduction of fuel 194 Cause of bad melting in this foundry ....... 19/) Warming up a cupola; Visit to the plant of the Providence Locomotive Works, Providence, R. I.; Trouble with the cupola .... 19H Cause of the poor melting due to the bed being burned too much . . 197 Remedy of the trouble; Bad melting caused by wood and coal ; Cause of poor melting in one of the leading novelty foundries in Philadelphia. 198 Poor melting in a Cincinnati cupola; Sectional elevation showing the condition of the cupola 199 Uneven burning of the bed; Reason for the necessity of dumping a cupola at the foundry of Perry & Co 201 CHAPTER X. Hot-Blast Cupolas. Early attempts to applj' the hot blast to cupola practice; Fallacy of the theory; Utilization of the heat from the cupola or of that escaping from the cupola stack; Method of utilizing this heat as applied by Jagger, Tread well & Perry, at Albany, N. Y .202 Failure of this plan 204 Arrangement for supplying a hot blast to the cupola with no expense for heating the blast; The Colliau hot-blast cupola .... 205 The Holland cupola 20ti Results obtained from the use of the Holland cupola; Analysis of the claims; Objection to heating blast in the way proposed . . . 208 Oil in cupola practice; Use of oil in the Holland cupola; Advantages claimed for the Holland cupola . . . . . . . 209 P.aillot's cupolas; Theory of oVjtaining a hot blast for a cupola . . 210 Claims made for the Baillot cupola by the manufacturers . .211 Record of experiments mane on a cupola of the Baillot system situated in the foundry of the Canada Car Co., Turcot Village . . . .214 CONTENTS. PAGE CHAPTER XI. Freezing the Bi.ast. Success in the saving of fuel by freezing the blast to drive out anj- moisture it may contain by blast furnace men; Difference between this practice in furnaces and in cupolas; Claim of hotter iron being ob- tained in winter; Mode of freezing the blast. ..... 215 Moisture in blast; Experiments made at The Lobdell Car Wheel Co., Wilmington, Del 216 Various methods of giving a moist blast; "Weather and the output of the cupola," by M. H. Bancroft; Air capacit}' for moisture . .217 Effect of heat on air . . 218 Load on blower or fan . . 219 Temperature of the air; Ratio of air and coke . . . . . 22(1 Temperature and moisture; Coke in summer and winter . . , . 221 "Moist or dry cupola blast," by Dr. Edward Kirk: Adding steam or water to blast . .222 Climate and hot iron; "Dry air for the cupola," comments by the Editor of "Castings". . . 228 CHAPTER XII. Cupola Euel.s. Coke Ihe best cupola fuel; Gas and liquid fuels; Reason why these fuels cannot be used in a cupola . 225 Experiments of melting iron in a cupola with gas and liquid fuels. . 226 Failure to produce a hot fluid iron ........ 227 Charcoal fuel; Superiority of iron produced with this fuel . 228 Mode of charging when melting with charcoal; Weight of charges of fuel and iron ............ 221i Anthracite coal as a cupola fuel; Pennsylvania hard coal fields . . 23(1 Difference in coal from the various mines in the same region; Opening of the first mine in the Pennsylvania districts . . . . . 231 Charging and melting with coal ........ 232 Heat melted with Old Mine Lehigh coal; Considerable variation in the per cent, of coal consumed in melting ....... 233 Per cent, of coal consumed in melting for one year at different found- ries; Size of coal used in melting . . ... . . . 234 Best results obtained in melting with coal . . . . . . 235 Mixture of coal with coke; Manner of charging and melting with mixed fuels 236 Heat melted in a 54-inch Whiting^ cupola with Schuylkill coal and Con- nellsville coke. ........... 237 Cupola coke; First coke made in ovens; First shipment of coke . • 238 Practice of foundrymen making their own coke ..... 239 xvi CONTENTS. PAGE Various grades of coke; Cause of failures in making coke; Superiority of the coal of the Counellsville region for the manufacture of coke. . 240 Use of gas-house coke for small heats; Requirements for the manufac- ture of a good foundry coke 241 Early practice in melting with coke 242 Mode of judging the melting qualities of a coke; Number of pounds of iron melted to pounds of fuel; Variation in the quality in the early days of coke 24H Cause of the variations in the quality of coke; Best cupola coke; 72- hour coke ............ 244 Manner in which iron is melted in a cupola furnace .... 245 Mistake by melters who do not understand the space theory of a cupola; Theory of melting which should be followed by every founder melting with coke. ............ 24t> Remedy in melting when coke is poor; Rule of charging coke and iron. 247 Weight of coke required for a bed; Measurement and weight the best guides for bed and charges ......... 248 Watching the melting for indications of necessary changes . . . 249 Difference of opinion as to the per cent, of coke to iron; Reports of melting with Counellsville coke and what is indicated by them. . 250 By-product coke; Extensive use of by-product coke; Properties of by- product coke 251 Bituminous coal as a cupola filel; Experience in melting with this fuel. 252 No deterioration in the quality of iron by the coal ..... 258 Selection of coal; A wonderful cupola; Mr. Herbert M. Ramp on this subject . . • 254 Comments on this wonderful cupola or melting record .... 255 CHAPTER Xin. Fluxing of Iron in Cupolas. Definition of a flux; Substances used as fluxes; Purpose of the use of limestone in the production of pig iron 25H On what the making of a brittle cinder in a cupola by the use of lime- stone depends; Limestone in large quantities ..... 25i> Variation in the quantity of limestone required to produce a fluid slag; Weight of slag drawn from a cupola 2H(li Constituents of the slag; Effect of flux upon iron; The action of fluxes on lining . . . . , 261 How to slag a cupola; Cause of trouble in slagging; General method of charging the limestone; The slag hole 26;i Slag in the bottom of a cupola; Importance of the time for drawing the slag; Does it pay to slag a cupola ? Estimate of the cost of slagging . 264 Shells; Use of oyster, clam and other shells; Cause of the crackling noise of shells when the heat first strikes them; Marble spalls . . 265 CONTENTS. xvii PAGE Experiments with mineral and chemical materials with the view of making a cheap malleable iron; Reason why iron is often ruined as a foundry iron by improper melting and fluxing ..... 266 Effect of silicon on iron; Per cent, of silicon an iron may contain; Use at the present time of a large amount of high silicon cheap Southern iron 267 Heav}' breakage due to the use of high silicon iron; Effect of carbon upon cast iron; Removal of free carbon from iron 268 Fluor spar and its use as a flux ......... 269 Cleaning iron by boiling; Poling molten iron 270 CHAPTER XIV. What a Cupola will Melt. Chief use of the cupola furnace; Employment of the cupola furnace for other purposes than melting iron; Quantity of cast iron that can be melted in a cupola . 272 Number of hours a cupola may be run; Size and weight of a piece of cast iron that can be melted in a cupola; Charging large pieces of iron at the foundry of the Pratt & Whitney Co., Hartford, Conn.; Melting of cannon and other heavy government scrap at the Lobdell Car Wheel Co., Wilmington, Del.; Melting large pieces of iron. . . 273 What should be done when the iron comes dull 274 Melting tin plate scrap in a cupola; Recovery of tin deposited upon the iron; Quality of the molten metal from this scrap 275 Experiments in melting this scrap ........ 276 Melting scrap sheet iron and galvanized sheet iron scrap; Melting tin- plate scrap 277 Construction of a cupola expressly for melting tin-plate scrap . . 278 Amount of profit in melting this scrap; Melting brass in a cupola; Ad- vantages presented by the cupola for this purpose .... 279 CHAPTER XV. Art in Melting. The art of melting iron in a cupola but little understood by many foundrymeu and foundry foremen; Troubles experienced in melting . 280 No chance work in nature or in art; Necessity of understanding the con- struction and mode of operation of a cupola to do good melting. . 281 Location and arrangement of the tuyeres; Preparation of the cupola for a heat; Ivighting up 282 Melting iron in a cupola a simple process; Things to be learned and practiced; Necessity of a close study of all the materials used in melt- ing • 283 XVlll CONTENTS. PAGE What should be the aim of every moulder; Advisability of the foreman of a foundry being the melter; Duties of the melter .... 284 Taking off the blast during a heat 285 Banking a cupola; Mr. Knoeppel, Foundry Superintendent, Buffalo Forge Co., Buffalo, N. Y., on this subject 286 Give the melter a chance; Respect due to the practical and scientific melter; Unfortunate position of a poor melter . ... 288 Interference with a good melter frequently the cause of poor melting; Necessity of furnishing proper tools for chipping out, and making up the cupola 289 What should be the aim of every melter; Interest of every foundryman to keep his melter posted 290 CHAPTER XVI. The CupoivA Accounts. Value of cupola accounts; Manner of keeping the accounts . . . 291 Cupola report of Abendroth Bros., Port Chester, N. Y 292 Cupola report of Byram & Co., Iron Works, Detroit, Mich. . . . 293 Daily report of Foundry Department, Lebanon Stove Works . . . 294 Melting sheet of Syracuse Stove Works 295 Report of castings in Shop 296 Cupola slate for charging and cupola report 297 Blanks for reports and records, and mode of making them out; Report on a slate; Correctness essential to the value of a cupola account; Cost of melting 298 Unreliability of melting accounts as generally kept; Objection to meas- uring fuel in baskets; Result of a supposed accurate account of the melting in a foundry in New Jersey 299 Proper method of figuring the cost of melting per ton .... 300 CHAPTER XVII. EXPI.OSION OF Moisten Iron. Conditions under which molten iron is explosive; Explosions caused by a wet spout or a wet bod 302 Cause of sparks; Various causes of the explosion of molten iron; Ex- plosion due to thrusting a piece of cold, wet or rusted iron into molten iron 303 Explosion of molten iron when poured into a damp or rusted chill- mould or a wet sand mould; Accident in the foundry of Wm. McGil- very & Co., Sharon, Pa. 304 Explosion of molten iron when poured into mud or brought in contact with wet rusted scrap; Accident in the foundry of James Marsh, CONTENTS. xix Lewisburg, Pa.; Accident at the foundry of North Bros., Philadel- phia, Pa 305 Explosions at the foundry of the Skinner Engine Co., Erie, Pa., and at the Buffalo School Furniture Co., Buffalo, N. Y 306 Prevention of explosions 307 CHAPTER XVIII. Getting up Cupola Stock. Oldest and original way of placing stock upon a cupola scaffold; Wheel- barrow runways ........... 308 Track runways; Elevators 309 The steam-hydraulic elevator manufactured by The Craig Ridgeway & Son Co. 310 Lifting magnets , 311 Crane with magnet attached used at the Baldwin Locomotive Works, Eddystone, Pa. ; Elevated stock yards; Stock yard of the Browne & Sharp Manufacturing Co., Providence, R. I. 313 CHAPTER XIX. Running a Continuous Stream. Advantages of running a continuous stream; Double spout; Device used at the Osborne Mower & Reaper Co., Auburn, N. Y 315 Basin spout; Cross spout in use at the foundry of The Lobdell Car Weeel Co., Wilmington, Del 316 Neat method of disposing of slag 317 Application of the cross spout to various purposes; Spout ladle . . 318 Reservoir spout ladle; J. W. Paxson Co. reservoir ladle .... 320 Tapping ladle; Advantages and disadvantages of this system . . . 321 Another plan for running a continuous stream. . ' . . . . 322 CHAPTER XX. Number of Men Required to Man a Cupola. Various conditions on which the amount of labor required depends; Mr. J. W. Keep's investigations and report 323 Summary of the melt compared with the necessary charging-floor labor. 324 Devices for charging cupolas; Mode of charging at the plant of the Carnegie Steel Works, Homestead, Pa. ... . • . 325 Endless chain carrying and charging device; English charging device; Use of the lifting magnet for charging ....... 326 Small charges for cupolas; Dr. Moldenke on this subject; Theory that every cupola is a law to itself; How the best results from a cupola are obtained 327 XX CONTENTS. Retaining heat in a foundry; Locations of cupolas in foundries; Preven- tion of waste of heat; Cupola dampers ....... 328 Protecting the melter when chipping out, and devices for this purpo.se. 329 Pig bed; Iron pig moulds; Construction of a pit-pig bed for pigging out; Protecting the pig bed .......... 330 Boiling or foaming slag .......... 831 Treatment of Inirns; New method of mixing daubing .... 332 Advantages of this method; Another way of mixing daubing . . . 333 Renewing a lining; Mica schist lining ....... 334 Common red brick lining .......... 335 Moor's patent cupola breast and runner ....... 336 CHAPTER XXI. SCIENTIFICAI,I.Y DESIGNED CuPOLAS. Scientific points presented by the various shaped linings, arrangement of tuyeres and distribution of blast; Objections to these scientific, fancy-designed cupolas .......... 337 Old style stave cupola in general use throughout the country many years ago. ............ 338 Practice of casting with the use of the old style cupola .... 340 Reservoir cupola; Expanding cupola 342 Ireland's cupola . . 344 Ireland's center blast cupola ......... 346 Voisin's cupola 348 Woodward's steam jet cupola 350 Objection to this style of cupola; Tank or reservoir cupola . . . 354 Production of soft iron by putting a quantity of charcoal on the sand bottom; Use of tanks in England 356 Mackenzie cupola ........... 357 Management of the Mackenzie cupola ....... 359 Dr. Otto Gmelin's cupola 361 Pevie cupola ............ 363 Object of Mr. Pevie in constructing a cupola upon this plan; Stewart's cupola ............. 365 Rapid melting in this cupola; The Greiiier patent economical cupola . 367 Steam jet cupolas; Experiments in melting in a cupola with steam with and without blast 369 Jumbo cupola ............ 371 Charge table for the Jumbo cupola . 372 Crandall improved cupola with Johnson patent center blast tuyere . 374 Claims for this cupola; Blakeney cupola 376 Preventing sparks from being carried out of the stack .... 377 CONTENTS. XXI PAGE CHAPTER XXII. Spark Catching Devices for Cupoi^as. Spark catcher in old-style cupolas; Modern spark arrester . . . 379 Return flue cupola spark catcher, designed by John O'Keefe . . • 382 Other spark catching devices . 884 The best spark catching device; Cupola hoods. ..... 385 Various kinds of hoods 386 CHAPTER XXIII. Cupola Straps. Brief paragraphs illustrating important principles; Terms used in differ- ent sections of the country to indicate the melting of iron in a cupola. 387 Best practical results for melting for general foundry work . . . 391 Remarks by Mr. C. A. Treat; Difficulty experienced by a fouudryman in obtaining reliable cupola reports for publication .... 392 CHAPTER XXIV. Blast Pipes and Blast. Blast pipes; Importance of the construction and arrangement of blast pipes; Underground blast pipes; Objections to this arrangement. . 394 Materials used in the construction of blast pipes; Galvanized iron pipes; Joints; Table prepared by the Buffalo Forge Co , Buffalo, N. Y., as a guide for increasing the diameter of pipes in proportion to the length. 395 Table showing the necessary increase in diameter for the different lengths 396 Diameter of blast pipes; Frequent cause of a blower being condemned as insufficient; Connection of blast pipes with cupolas . . . . 397 Connecting blast pipes direct with tuyeres; Combined area of the branch pipes; Table of diameter and area of pipes ...... 398 Perfect connection of air chambers; Poor arrangement of pipes . . 399 Mode of connecting a belt air-chamber with the tuyeres; Best way of connecting blast pipes with cupola tuyeres 401 Blower placed near cupola 402 Poor melting often caused by long blast pipes; Perfect manner of con- necting the main pipe with an air chamber; Placing a blower; Con- venient way of placing a blower near a cupola ..... 403 Blast gates; Advantage of the employment of the blast gate . . . 404 Explosions in blast pipes; Prevention of such explosions; Blast gauges; Variety of gauges 406 Indication of the pressure of blast; What an air-gauge to be of any value in melting must indicate 407 XXll CONTENTS. PAGE Blast in melting; Means for supplying the required amount of air to the cupola; Machines for suppl3-ing the blast 408 Relative merits of a positive and non positive blast. .... 409 Amount of air required for combustion of the fuel in melting a ton of iron; Theory of melting in the old cupolas with small tuyeres . . 410 Points to be remembered in placing tuyeres in a cupola; Best tuyere for large cupolas 411 Size of the largest cupolas in which air can be forced to the center from side tuyeres; Cupolas of the Carnegie Steel Works, Homestead, Pa.; Experiments with a center blast tuyere 412 Claims for the center blast 413 CHAPTER XXV. Blowers. Types of blowers 414 The Green patented positive pressure blower; Connersville cycloidal blower ............. 415 Sectional view of this blower; Advantages of this arrangement . . 416 Horizontal blower; Numbers, capacities, etc., of the cycloidal blowers . 419 Vertical blower and engine on same bed-plate. . . . . . 420 Blower and electric motor 421 Root's rotary pressure blowers 422 Root's horizontal pressure blower 423 Garden City positive blast blower 424 Claims made for this blower; Sturtevant high pressure blowers . . 425 Principal parts of which the blower consists 426 Piqua positive blowers; Fan blowers; Sturtevant blowers . . . 428 Steel pressure blowers 429 Steel pressure blowers on adjustable bed with combined upright engine. 430 Electric steel pressure blowers ......... 431 Buffalo steel pressure blower ......... 433 How to obtain the best results from a blower of given size . . • 435 Blower on adjustable bed with combined countershaft .... 436 Buffalo blower for cupola furnaces in iron foundries .... 437 Table of speeds and capacities as applied to cupolas; "A. B. C" steel pressure blowers of The American Blower Co 438 Summary of the advantages of these blowers 439 CHAPTER XXVI. Foundry Tramrail. Most efficient method of foundry transportation; Construction of the tramrail 442 The tramrail as used in the average foundry; Dumping scrap and coke directly into the cupola 443 CONTENTS. xxiii Insertion of a scale in the rail; The tramrail in foundries of larger capacities 444 Saving in labor effected by the installation of an electric tramrail; Tram- rail for carrying molten metal from the cupola 445 Provision for continuous pouring; Transportation of ladles . . .446 Index 449 CHAPTER I THE CUPOLA FURNACE The cupola furnace has many advantages over any other kind of furnace for foundry work. It melts iron with less fuel and more cheaply than any other furnace, and can be run intermittently without any great damage from expansion and contraction in heating and cooling. Large or small quantities of iron may be melted in the same furnace with very little difference in the per cent, of fuel consumed, and the furnace can readily be put in and out of blast. Con- sequently in all cases where the strength of the metal is not of primary importance, the cupola is to be preferred for foun- dry work. In the reverberatory furnace from ten to twenty cwt. of fuel is required to melt one ton of iron. In the pot furnace one ton of coke is consumed in melting a ton of cast iron, and two and a half tons in melting a ton of steel. In the blast furnace twenty to twenty-five cwt. of coke is consumed in the production of a ton of pig iron. In the cupola furnace a ton of iron is melted with from 172 to 224 lbs. of coke. It will thus be seen that in the cupola furnace we have the minimum consumption of fuel in melting a ton of iron, although the amount consumed is still three or four times that theoret- ically required to do the work. Many attempts have been made to decrease even this small amount of fuel consumed in the cupola, by utilizing the waste heat passing off from the top for heating the blast. But the cupola being only intermittently at work has rendered ail such attempts futile. 2 THE CUPOLA FURNACE. The cupola furnace is a vertical furnace consisting of a hollow casing or shell, lined with fire-brick or other refractory material, resting vertically upon a cast-iron bottom plate, having an opening in the center equal to the inside diameter of the lining and corresponding in shape to the shape of the furnace. This opening is closed with iron doors covered with sand when the furnace is in blast. Two or more openings are provided near the bottom of the furnace for the admission of air by draught or forced blast. A small opening, on a level with the bottom plate, is arranged for drawing ofif the molten metal from the iurnace. An opening, known as the charging door, is made in the side of the casing at the top of the furnace for feeding it with fuel and iron, and a stack or chimney is constructed above the charging door for carrying off the escaping smoke, heat and gases. Cupolas have been constructed cylindrical, elliptical, square and oblong in shape, and they have been encased in stone, brick, cast iron and wrought iron casings. From one to a hundred or more tuyeres have been placed in a cupola, and the stationary and drop bottoms have been used. At the present time cupolas are constructed almost entirely in a cylindrical or elliptical form, and the casing is made of wrought iron or steel boiler plate. The stack casing is made of the same material and is extended up to a sufficient height to give draught for lighting up, and to carry off the escaping heat and gases. The drop bottom has been almost universally adopted, at least in this country. Cupolas are constructed of various sizes, to suit the require- ments of the foundry they are to supply with molten metal. Those of large size are, when charged with iron and fuel, of immense weight, and require very solid foundations to support them. The foundation is generally made of solid stone work up to the level of the foundry floor; upon this is placed brick work laid in cement, or cast-iron columns or posts, for the sup- port of the iron bottom and cupola. In all cases where the cupola is set at sufficient height from the floor to admit of the THE CUPOLA FURNACE. 3 use of the iron supports they are to be preferred to brick work, as they admit of more freedom in removing the dump and re- pairing the lining. The columns or posts are placed at a suffi- cient distance apart to permit the drop doors to swing free between them. This arrangement removes the liability to breaking the doors by striking the cupola supports in falling, and admits of their being put back out of the way when remov- ing the dump. The height of the bottom of the cupola above the mould- ing floor depends upon the size of the ladles to be filled, and varies from fourteen inches to five feet. If placed too high for the sized ladle used, considerable iron is lost by sparks and drops separating from the stream in falling a long distance, and the stream is more difficult to catch in the ladles. For hand ladle work it is better to place the cupola a little higher than fourteen inches, and rest the ladle upon a hollow oblong ped- estal eight or ten inches high, and open at both ends, than to set it upon the floor. The ladle can then be moved back or forward to catch the stream, and iron spilled in changing ladles falls inside the pedestal, and is prevented from flymg when it strikes the hard floor, and is collected in one mass inside the pedestal. This arrangement reduces the liability of burning the men about the feet and renders it easier to lift the full ladle. If a cupola is set very low, it is then necessary to make an excavation or pit beneath it to permit of the removal of the dump, and repairing of the lining. This pit is made as wide as it con\'eniently can be, and of a length equal to two or three times the diameter of the cupola. The distance from the bottom plate to the bottom of the pit should not be less than three feet. The bottom of the pit is lined with a hard quality of fire-brick set on edge, and the floor sloped from the edges to the center, and from the end under the cupola outward, so that any molten iron falling with the dump will flow from under the cupola, and thus facilitate its removal. In the center of the pit under the cupola a block of stone or a heavy. block of iron is securely placed, upon which to rest the prop for the support ■of the iron bottom doors. 4 THE CUPOLA FURNACE. The bottom plate is made of cast iron, and must be of sufficient thickness and properly flanged or ribbed to prevent breaking. If broken when in place, it can not be removed, and it is then almost impossible to securely bolt it so as to hold it in place. The plate must be firmly placed upon the iron supports or brick work, so that no uneven strain will be put upon it by the weight of the cupola and stack. The bottom doors are made in one piece or in two or more sections. For large cupolas the}' are generally made in two or four sections to facilitate raising them into place. They are made of cast or wrought iron. Those made of cast iron are, when in place, the stififest and firm.est. Those made of wrought iron are the lightest and easiest to handle, but are also more liable to be warped by heat in the dump, and to spring when in place. The door, or doors, whether made of cast or wrought iron, have wide flanges to overlap the bottom plate and each other when in place, to prevent the sand, when dry, running out through cracks and making holes in the sand bottom. The doors are supported in place by a stout iron or wooden prop; and when they are light, or sprung, one or more additional props are put in for safety. Numerous bolts' and latches have been devised for holding the doors in place, but they have all been abandoned in favor of the prop, which is the safest. Sliding doors, or plates, have been arranged upon rollers to slide into place under the cupola from the sides, and be withdrawn by a ratchet or windlass to dump the cupola. They admit of easy manipulation ; but in case of leakage of molten iron through the sand bottom, they are sometimes burnt fast to the bottom plate and cannot be withdrawn, and for this reason the sliding door is seldom used. The casings are made of cast or wrought iron plate. When made of cast iron they are cast in staves, which are put in place on the iron bottom and bound together by wrought iron bands ; these bands being shrunk on. Or they are cast in cylindrical sections, which are placed one on top of another, and bolted together by the flanges. This kind of casing generally cracks THE CUPOLA FURNACE. 5 from expansion and shrinkage in a short time, and is the poor- est kind of casing. With the cast iron casing a brick stack, constructed upon a cast iron plate supported by four iron col- umns, is generally used. The wrought iron casing is more generally employed at the present time than that of cast iron. It is made of boiler plate, securely riveted together with one or two rows of rivets ; but one row of rivets, and those three inches apart, is generally found to be sufficient, as the strain upon the casing, when properly lined, is not very great. The stack casing is generally made of the same material as that of the cupola, and in continuation of the cupola casing; the two generally being made in one piece. The stack is made the same size as the cupola, or is con- tracted or enlarged according to the requirements or fancy of the foundryman. A contracted stack gives a good draught, but throws out a great many sparks at the top. An enlarged stack gives a poor draught, unless it is very high, but throws out very few sparks at the top. As sparks are very objection- able in some localities, and not in others, different-sized stacks -are used. When surrounded by high buildings or hills, the stack must be made of sufficient height to give the necessary draught for lighting up in all kinds of weather, and then vary in height from a few feet above the foundry roof to twenty or thirty feet. Bands of angle iron are sometimes riveted to the inside of the cupola and stack casings to support the lining, and admit of sections being taken out and replaced without remov- ing the entire lining. The casing and lining are perforated with two or more tuyere holes near the bottom, for the admission of air by draught or forced blast. These tuyeres, when supplied with a forced blast, are connected with the blower by branch pipes to each tuyere, or are supplied from an air chamber riveted to the ■cupola casing either on the outside or inside. The air chamber is made three or four times the area of the blast pipe, and is sup- plied fron^ the blast pipe connecting it with the blower. An -opening is made through the casing and lining, just above the O THE CUPOLA FURNACE. bottom plate, for drawing the molten iron from the cupola, and a short spout is provided for running it into the ladles. An- other small opening is sometimes made, just under the lower level of the tuyeres, for tapping or drawing off the slag from the cupola. This opening is never used except when a large amount of iron is melted, and the cupola is kept in blast for a number of hours. An opening for feeding the furnace, known as the charging door, is placed in the cupola at a height varying from six to twenty feet above the bottom plate, according to the diameter of the cupola. This opening is sometimes provided with a cast iron frame or casing on the inside to protect the lining around the door when putting in the fuel and iron. A door frame is placed upon the outside, upon which are cast lugs for a swinging door, or grooves for a sliding door. The door for closing the charging aperture may consist of a cast or wrought iron frame filled with fire-brick, or be made of boiler plate with a deep flange all around for holding fire-brick or other refrac- tory material. The sliding door consists of an iron frame filled in with fire-brick, and is hung by the top, and moved up. and down with a lever or balance weights. This door is moved up and down in grooves cast upon the door frames, which grooves frequently get warped by the heat, and hold the door fast. The hinge or swing door, with plenty of room for expan- sion and shrinkage, is the door generally used. The casing is lined from the bottom plate to the top of the stack with a refractory material. A soft refractory fire-brick, laid up with a grout composed of fire-clay and sand, is used for lining in localities where such material can be obtained. In localities where fire-brick can not be procured, soapstone from quarries or the bottoms of small creeks, is laid up with a re- fractory clay. Some grades of sandstone or other refractory substance are also employed for lining. Native refractory materials are seldom homogeneous, and those which have been ground and moulded, or pressed into blocks, make the best lin- ings. The thickness of the lining varies in large and smalt THl': CUPOLA FURNACE. 7 cupolas. Those in the large cupolas are from six to nine inches, and in small cupolas from four to six inches. The charging aperture being placed at too great a height from the floor to admit of the cupola being charged or loaded from the floor, a scaffold or platform is erected from which to charge it. The scaffold is generally placed in the rear of the cupola, so as to be out of the way when removing the molten iron in crane ladles. But for hand-ladle work it is placed at any point most convenient for getting up the stock, and the charging aperture placed in the cupola at any point most con- venient for charging. For very large cupolas the scaffold is frequently constructed to extend all around the cupola, and a charging aperture is placed in the latter on each side, so that it may be more rapidly charged. The scaffold is constructed of wood or iron frame work, or is supported by a brick wall. The floor is placed level with the bottom of the charging aperture, or is placed from one or two feet below it. The scaf- fold should be made large enough to place a weighing scale in front of the charging door, to hold iron and fuel for several heats, and have plenty of room for handling the stock when stocking the scaffold and charging the cupola. Nine-tenths of the scaffolds are too small for the work to be done on them, and the cupola men work to a great disadvantage when hand- ling the stock. Much of the bad melting done in foundries can be traced directly to the lack of room on the scaffold for properly charging the cupola. CHAPTER II. IMPROVEMENTS IN CUPOLAS. From the best information obtainable, it appears that the first cupola furnaces used in foundries in this country were of the type of the stationary bottom draw front cupola. These were constructed upon a solid stone or brick foundation from three to four feet high, or upon a hollow foundation with a cast iron plate on top, upon which a cupola bottom of fire-brick or other refractory material was placed. The cupola castings were generally made of cast iron, with the front opening of a sufificient size to admit of the refuse from melting being drawn from the cupola through the front with an iron hook or rake. The lining was arched over the front and the opening closed with an iron plate or apron, which was put in place when the lining and bottom had been repaired and made ready for a heat and securely fastened with hooks or other devices. To protect the apron, a temporary lining was put in of loam or other material that could be readily removed while hot after the heat was melted. When the cupola was large the apron was put in place and the temporary lining put in before the fire was lighted, and in small ones a wall of coke was built up in the opening, and the loam or other material rammed into the front after the fire was burned up, and the apron placed over it. A small open- ing or front was placed in the apron for the tap hole. This style of cupola was the only one used in this country for many years, but it has now generally been replaced by more modern ones. Probably three of the most perfectly con- structed cupolas of this design ever built in this country were (8) IMPROVEMENTS IN CUPOLAS. 9 those in the foundry plant of Chas. Reeder & Sons, Baltimore, Md. These cupolas were inconstant use until about two years ago when the plant was abandoned and torn down. These works were established in 1813 for the manufacture of marine and stationary engines, and some of the largest and most pow- erful marine and stationary engines constructed in early days were cast at this foundry. To melt iron for these castings, three draw-front cupolas were constructed upon the latest improved pattern of the times; the exact date at which they were built is not known, but it must have been many years ago, for the old foreman in 1874 informed me they were used in melting the iron for cast- ings of marine engines placed in well-known vessels, that had long been out of existence at that time. The cupolas at the time of my last visit to the works, some years ago, were the only ones in the foundry, having held their own against all the changes in fashion, until they became the leaders of fashion, for the draw front has again come in use to a considerable extent during the past few years for very small cupolas. These cupolas, three in number, were placed in a row close together upon a cast iron plate supported by a brick foundation three feet high. Upon this plate eight cast iron columns ten feet high were placed, for the support of the stack plate upon which rested the cupola stack. The casings of the cupolas and stack were made of boiler plate, the stack was placed directly over the center cupola with side wings extending over the others on •either side, so that one stack served for the three cupolas, which were of dititerent sizes. The smallest one was straight and 20 inches in diameter inside the lining. The other two were taper- ing from bottom to top, one with a diameter inside lining of 42 inches at tuyeres, 36 inches at top, and the other 48 inches at tuyeres and 40 inches at top. The tuyeres were square and placed 16 inches above bottom. The larger cupolas had four tuyeres and the small one two. The cupola castings were all of the same height, measuring ten ieet between bottom and top plate, but the charging door, 24 lO THE CUPOLA FURNACE. inches high, was phiced in each cupola below the top plate, which reduced their height to 7^ or 8 feet. The cupola scaffold was very small, having scarcely sufficient room for stock for the small cupola. This appears to have been the general way of constructing scaffolds in early days, the practice being to only place stock upon the scaffold as it was required for charging, one man placing it in the cupolas as fast as one or more men threw it upon the scaffold from the stage or platform upon which fuel and iron were thrown in passing it up from the yard to the scaffold. There do not appear to have been any cupola runways or elevators in " our grandfathers' day." One of these cupolas, I was informed, was changed to a drop bottom about the time the drop bottom first came into use, but after the loss of a number of heats, from the support of the bottom giving way or leakage through the sand bottom, it was changed back to a stationary bottom, which was considered safer than the drop. These cupolas did good work in a number of heats I saw melted in them ; in fact, they melted equally as well as any of the more modern cupolas of the same diameter and height, of which there were a great many in use at the time referred to. But the refuse from melting was not so easily removed as from the more modern cupolas. When the apron was removed and the front broken away, the refuse under the tuyeres was readily drawn out, but after this was removed cold air was ad- mitted, which chilled the slag and cinder over the tuyeres, ren- dering it tough and difficult of removal, and when the cupola was slightly bridged and the refuse did not drop freely, it was almost impossible to remove it. This difficulty occurred so frequently that a long bar was kept on the scaffold for poking the refuse down and getting a hole through, that it might cool off by the next morning. This is the great objection to the draw-froht cupola, which is overcome to a considerable extent by the drop-bottom, which gives way the instant the support is removed and permits every- thing to drop out when the cupola is not bridged, before it has time to become chilled and tough. IMPROVEMENTS IN CUl'OLAS. II Melters who have never melted in a large stationary bottom cupola have little idea of what a great boon this w as to melters, in the early days, when the tapping of slag from cupolas was not thought of, and it was a common thing to work one or' more hours to get a hole through after each heat. The drop bottom is said to be an American invention and to have been first used in the New England States, but there ap- pears to have been no record of the date at which it was first used, and the oldest foundrymen I have met have not been able to give the date at which it was first introduced. But so far as I have been able to learn, it has been in use at least fifty years, and perhaps longer, but it was not adopted by all founders when it was first introduced, and many of the sta- tionary bottom cupolas of the old pattern were in use at a much later date, and may still be in use in some of the old foundries like the one before referred to. With the introduction of the drop bottom cupola there does not appear to have been any other change made in the con- struction of cupolas. They were generally built upon a brick or stone foundation, with square cast-iron bottom plates, upon the corners of which were placed four columns for the support of another plate upon which was constructed a square stack of common red brick. The stacks were generally made of a much larger area than the cupolas, that the red brick of which they were constructed might not be burned out and also to prevent sparks or hot cinders being thrown out at the top of the stack. The charg- ing door was generally placed in the stack just above the plate_ Cupola castings were generally made of cast iron and were cast in staves the length or height of the cupola and from four to six inches \\ide. These staves rested upon the bottom plate and projected up through an opening in the stack plate several inches, or came even with the top of it, and were held together by wrought-iron bands placed a foot or more apart. When boiler plate was obtainable and it was desired to have some- thing fine, castings were made of this material, but the cast-iron 12 THE CUPOLA FURNACE. Stave casings were more common. Small cupolas were gener- ally made straight and large ones tapering, with the larger end down to facilitate dumping, and their height was from six to eight feet, eight feet being considered a very high cupola. Blast was supplied through two tuyeres, one placed on either side of the cupolas, and opposite each other, so that blast from each met in the center. When only light work was to be cast they were placed twelve to eighteen inches above the bottom ; for heavy work, three sets of tuyeres, one above the other, were put in. They were generally placed twelve, eighteen and twenty- four inches above the bottom. These tuyeres were designed for melting iron for a heavy casting, and when such a piece was to be cast, blast was first put in through the lower ones until the cupola was filled with molten iron to this point. They were then closed with clay and the next set opened, and blast put in until molten iron appeared, when they were closed and the next set opened. To admit of blast being adjusted to the tuyeres of dififerent heights, a tuyere pipe or nozzle of tin or copper was provided and attached to the blast pipe by a leather tube, one end of which was slipped over the blast pipe and the other over the end of the nozzle and securely tied with a leather thong or lace. A hole was placed in the bend of the nozzle or elbow and closed with a wooden plug for watching the filling up of the cupola with molten iron, and also for poking the tuyeres when they became black. To admit of the blast being adjusted to the different height of tuyeres when the cupola was in blast, the iron and fuel were not placed in charges, but were mixed by putting in a shovel or two of fuel and a hundredweight or two of iron. This was the common practice of filling the cupola. This plan of melting for heavy castings did not prove very satisfactory, and later on, in cupolas designed for heavy work, but one set of tuyeres was put in, and these located 24 inches above the bottom ; these gave better results than the adjustable tuyeres. IMPROVEMENTS IN CUPOLAS. 13 Tuyeres were mostly made very small for the purpose of putting in the blast with great force, and driving it to the center of the cupola, and were generally made from 3 to 5 inches in diameter, according to the diameter of the cupola. Two of these small tuyeres were considered ample for a small cupola and four for a large one. These old-fashioned cupolas, in many of which I have melted iron, generally melted very slow. This was due to the tuyere area being entirel)' too small to supply a sufificient volume of blast and to the cupolas being too low to utilize all the heat of the fuel for heating the iron and preparing it for melting, before settling into the melting zone. With a cupola only seven feet high, tuyeres 24 inches above the bottom, and top of bed 18 to 20 inches above tuyeres, only 3 to 33^ feet was left for fuel and iron above the bed. It is obvious to almost any founder nowadays, that this was not sufficient space in which to utilize all the heat of the fuel ; but this was not the case some years ago, and when I published my first work on foundry practice in 1877, in which I placed a table for heights of cupolas, ranging from 6 to 15 feet, according to diameter of cupolas. This table was ridiculed by the majority of foundrymen, and a 15-foot cupola was declared by many to be impracticable ; but the heights given in this table have all been reached and in many cases passed, and the tendency at the present time is to go to the other extreme and overreach the height at which the heat that can be utilized is sufficient to pay for the extra expense of cupola, lining, elevating stock, etc. There are a few of these old-fashioned brick stack cupolas still in use. There is at least one in Philadelphia, Pa., and two or three could probably be located in Brooklyn, N. Y., and a few in other places, but they have generally given place to the more modern cupolas. There does not appear to have been any improvement made in cupolas for many years after the adoption of the drop bot- tom, and they were all constructed with stave casings, brick stacks, etc. The next advancement was the use of boiler- plate 14 THE CUPOLA FURNACE. casings for both cupola and stack, and construction of cupola and stack in one piece, doing away with the cast-iron staves, columns, stack plates and brick stacks. Following this came the abandonment of the adjustable tuyere, nozzle, leather tube, etc., the enlargement of tuyeres, use of variously shaped tuyeres, attachment of blast pipes to cupolas, introduction of tuyere boxes, air chambers, etc. ; any and all of which were a great improvement over the tuyere nozzle and leather tube, which frequently permitted as great an amount of blast to escape as passed into the cupola. About this time the taper was also abandoned and cupolas of all sizes made of the same diameter from bottom to top. With the increase in size of tuyeres, and more perfect con- nection of blast pipes with cupolas, it became apparent from the amount of heat at the charging door that cupolas were too low, and their height was increased from time to time, until heat no longer appeared at the charging door sufficient to burn the hand when the cupola was filled with slock and in full blast. The next improvement was the lowering of the tuyeres from 12, 18 and 24 inches above the bottom to from 4 to 10 inches above the bottom, and in many of the large cupolas they were placed so low that the sand bottom came up to the bottom of the tuyeres at back of cupola. These changes were all effected in the common straight cupola, and brought it to such a perfection as a melter of iron many years ago that it is very doubtful if any improvement has been effected in cupolas since that time. Before these improvements were made cupolas melted very slow, and it was the practice to put on the blast just after the noon hour and melt all afternoon. From four to five hours were commonly required to melt any ordinary heat. Holders generally stopped molding when the blast was put on, and a great deal of valuable time was lost waiting for iron. To prevent this loss of time, Mr. Mackenzie, a practical molder and founder of Newark. N. J., conceived the idea of melting a heat in two hours, and designed the Mackenzie cupola, which, when first introduced, was known as the two-hour cupola. IMl'ROVEMENTS IN CUPOLAS. 1 5 This cupola, I believe, was the first cupola patented in this country, and it presented a number of new features in cupola construction. The old theory of driving blasts to the center of the cupola by force of the blower and the small tuyeres was entirely abandoned, and the theory of supplying a sufficient volume of blast to fill the cupola adopted. Cast-iron tuyere boxes were bolted to the castings for the attachment of blast pipes, and blast was delivered to the cupola from an inside belt air chamber and continuous tuyere. The air chamber which was formed by an apron riveted at the top to the cupola shell was entirely open at the bottom, giving unlimited space for escape of blast into the cupola. This was a complete change from the old theory of putting blast into a cupola with great force, and revolutionized the theory of melting. This cupola gave excellent results, and was adopted by all the leading foundrymen of the time, and many of them are still in use. and continue to give good results in melting wlien properly managed. But this cupola has its objectionable features, the greatest of which is its tendency to bridge and bung up when not properl}' managed. This tendency to bridge is due to a large extent to the cupola being boshed by the inside air chamber, and the blast being supplied to it just at the point of the lower angle of the bosh. The blast passes up over the bosh before it becomes heated, causing a chilling of cinder and slag at this point, and the building-out of the lining with a very hard substance that is difficult to remove, and careless or incompetent melters frequently permit the lining to grow at this point until the melting capacity of the cupola is reduced one-half, and the smaller ones frequently bridge before they are in blast more than an hour when the lining is permitted to get out of shape. Much better results might have been obtained from this cupola had the inventor furnished, to be hung up near the cupola for the guidance of the melter, a framed diagram or blueprint, showing the proper shape for lining of the bosh and 1 6 THE CUPOLA FURNACE. melting zone when the hning was new and as it burned away; but such a diagram was never furnished, and I have frequently seen melters running these cupolas who did not have the least idea of the shape the lining should be put in when repairing it for a heat, having never seen one when newly lined or in shape. The next patent cupola to come into prominence was the Truesdale cupola, designed by Mr. Truesdale, foreman of the Resor Stove Works, Cincinnati, Ohio. This cupola was sup- plied with blast from an inside belt air chamber through the Truesdale reducing tuyere, which consisted of a series of open- ings through the lining placed one above the other only an inch or two apart, the diameter of each reduced half an inch from the one directly under it. The lower tuyere was from 3 to 4 inches in diameter, accord- ing to diameter of cupola, and the top one, one inch in diam- eter. A sufficient number of these tuyeres were placed in a cupola to admit a proper volume of blast for melting ; the object of these tuyeres being to distribute the blast to different parts of the bed in a sufficient volume to produce a rapid and thor- ough combustion of the fuel. This arrangement gave excellent results in cupolas of large diameter, but was not so satisfactory in small cupolas, as the tendency to bridge was increased by the inside air chamber and arrangement of tuyeres. The cupola was designed for melting with coke only, and its use was restricted to the West, the greater number of them being used in Cincinnati and vicinity, where some are probably still in use, but most of them have been replaced by more modern cupolas. The next patent cupola to come into prominence was the Lawrence cupola, designed and patented by Mr. Frank Law- rence, foreman of the American Stove and Hollow Ware Co., Philadelphia, Pa. This cupola was designed for melting with coal or coke, and was quite extensively used both in this country and Canada. Its principal feature was a reducing tuyere, consisting of an opening 3 or 4 inches square, directly over which was. an up- IMPROVEMENTS IN CUPOLAS. I 7 li^ht slot opening 10 to 12 inches long and i to i ^ inches wide at the bottom, and tapering to a point at the top. These tuN'eres, like the Truesdale, were su[)plied with air from an inside air chamber, and were designed to distribute the blast to produce a more rapid and thorough combustion than when all the blast was admitted at the same level. The cupola was gen- erally boshed and the casings of the larger ones were enlarged in the center, giving them an egg shape between the top of the tuyeres and bottom of the stack, the charging door being placed in the stack. The cupola, when of good size, was the most rapid melter with coal ever designed, and was quite extensively used with this fuel. Another cupola that attracted some attention was the Pcvie cupola, designed by Mr. Pevie, a practical foundryman of a small town in Maine. This cupola was an oblong or fiat one from 20 to 30 inches wide and from 4 to 6 feet long. Bla^t was admitted to it through a horizontal slot tuyere placed on each side and extending the full length of the cupola. The (object of this construction was to force blast to the ceater of the cupola and produce even melting, which it no doubt did. But the tendency of the cupola to bridge was so great that it never came into general use. only a few of them being placed in foundries. Of these I have seen only four, one of which was in Mr. Pevie's own foundry, and judging from the number of cupola salamanders lying around, the inventor had not himself been able to overcome the tendency of the cupola to bridge. Another cupola, or rather tuyere, which came into promi- nence in Philadelphia and vicinity was " The Dougherty," designed by Mr. Dougherty, of the firm of Dement and Dough- erty. This improvement consisted in placing tuyeres in a cupola in such a manner as to give to the blast a circling or swirling motion around the cupola through the stock, in place of passing straight in and up through the stock. This arrange- ment for some time was considered to improve the melting, and many of these tuyeres were placed in cupolas ; but after a thor- ough test there proved to be nothing in this motion given to 2 I 8 THE CUPOLA FURNACE. the blast, and, like many other improvements, the tuyere was abandoned. All of these cupolas that, met with any success, depended for this upon the shape of the lining or arrangement of the tuyeres, and when these were maintained as originally designed good results in melting were obtained. But when placed in the hands of the average melter these conditions were ignored. Linings were permitted to get out of shape, tuyeres closed up or collapsed, directions for melting were not followed, and the cupola sooner or later in a vast majority of cases proved a complete failure and was changed to a plain cupola or replaced with the old-fashioned straight, lound cupola, which demon- strates that fancy shapes in linings or the distribution of blast to the bed through numerous small or fancy shaped tuyeres, is not practical in cupola practice, and sooner or later proves a complete failure. Following these fancy-shaped and numerous-tuyered cupolas came the " Colliau " plain round cupola, designed by Mr. Colliau, and first introduced about 1874 or 75. This cupola was designed to be a fast and economical melter as well as a continuous melter But when first introduced it proved such a complete failure that Mr. Colliau's financial partner committed suicide, and Mr. Colliau himself was on the verge of bankruptcy ; but he persevered, and after numerous changes finally suc- ceeded in making it the leading cupola of his, and of the present, time. The cupola, when first introduced, presented a number of new features in construction and management, among which were a hot blast, a double row of tuyeres, the tapping of slag, etc. The hot blast was to be produced by extending the air chamber from the bottom of the cupola up to near the charg- ing door, on the outside, and heating the blast with heat escap- ing through the cupola shell. The heat escaping through the shell was found to be insufficient to heat the blast, and this feature was a complete failure, and after constructing a few cupolas on this plan it was abandoned as impracticable. Had IMPROVEMENTS IN CUPOLAS. 1 9 Mr. Colliau applied this theory to some of the old-fashioned stave cupolas, in place of a tight boiler-plate casing, he might have met with more success, and he probably got his idea from these cupolas, for I have seen sufficient heat escape from them to at least warm a blast, if not heat it, by surrounding the en- tire cupola with a belt air chamber and passing the blast through it before entering the cupola through the small tuyeres then in use. The double rows of tuyeres were also a failure when first introduced, and it was found to be almost impossible to make hot iron with double the amount of fuel required for a bed to make hot iron with a single row of tuyeres, and the use of the cupola was restricted to foundries making heavy work and not requiring very hot iron. This objectionable feature was finally overcome by reducing the size of the upper row and placing them nearer to the lower row or lower in the cupola. The tapping of slag and the con- tinuous melting was a success from the beginning, and this was all that saved the cupola from a complete failure. The tapping of slag from blast furnaces had long been in vogue in this country, but Mr. Colliau was the first to apply this system of melting to cupolas, and it proved a decided ad- vantage in long heats, for prior to its introduction it was almost impossible to run a small cupola for a greater length of time than two hours, or a large one for more than four, and do good melting. Mr. Colliau also changed the form of cupola supports, bot- tom doors, air chambers, adopted a scale of heights for cupolas of different diameters, and probably did more to advance cupola construction in this country than any other cupola designer. His designs both before and after his death were adopted by other cupola manufacturers, and the general construction of cupolas at the present time is upon the Colliau plan. The double row of tuyeres was not original with Mr. Colliau. They had been used in France, prior to his introduction of them in this country, and the Truesdale and Lawrence tuyeres were practically on the same principle, applied in a little differ- 20 TITE CUPOLA FURNACE. cnt form, but the Colliau arrangement was not so apt to close up and get out of order, and was more practical, and has come into general use. The utility of these tuyeres depends to a large extent upon the conditions under which 'hey are used. They require a higher bed and are more destructive to lining material than the single row of tu}-eres, and in foundries employing a small num- ber of moulders and running short heats they arc an expensivr luxury. The manufacturers of cupolas have realized this fact and arranged a device for closing the top row when large heats for the size of cupola are not to be melted, and in fully nine-tenths of these cupolas in use, I find the second row cither perma- nently or temporarily closed, which places the cupola in the same condition as the improved cupola of " 40 years ago." The double row mchs iron more rapidly than the single rt)w in cupolas of the same diameter, and a third and fourth row have been added to advantage in this res[)ect when properly arranged. But the destruction of lining material from the use; of these numerous tuyeres is very heavy and the amount of fuel required is greatly increased. In foundries employing a large number of molders and melt- ing heavy heats, rapid melting increases the output of the foundry to a considerable e.xtent by allowing more time for molding work, and these numerous tuyere cupolas are being used with good results in foundries of this class ; the heavy de- struction of lining material and increased expenses of melting being more than overcome by the increased output of tlic foundry. It is therefore a matter for every founder to decide whether it is more economical to melt fast or slow, the actual cost df cupola lining, etc., being a secondary consideration when offset by other conditions. I might describe numerous other cupolas I have seen in operation, but those just described embrace all the principles embodied in other new designs of cupolas and arrangement of IMPROVEMENTS IN CUPOLAS. 2 1 tuyeres, nearly all of which have gone out of use or are being used only to save expense of replacing them with other cupolas. After all the supposed improvements we have practically come back to the plain round cupola of 40 years ago, with practically no improvements, save the enlargement of tuyeres and increase in height of cupola. These improvements have made the common round cupola superior to any other for gen- eral foundry use, and with the improvement made in blast machinery enormous quantities of iron may be melted in it in a very short time with the single-row tuyere cupola, and with the double and triple tuyere arrangement more iron may be melted per hour than the output of our most improved blast furnaces for the same length of time. The common round cupolas with the single or double row of tuyeres, as desired, are now manufactured by numerous cupola manufacturers located in different parts of the country, and founders who contemplate putting in new cupolas will probably find it cheaper to order a cupola with such changes in its construction as they may desire than to go to the expense of making patterns and constructing their own cupola. CHAPTER III. CONSTRUCTING A CUPOLA. When about to construct a cupola to melt iron for foundry- work, the first thing to be decided on is the proper location. In deciding this a number of points are to be taken into consider- ation, the two most important of which are the getting of the stock to the cupola and the takmg away of the molten iron. It should be borne in mind that there is more material to be taken to a cupola than is to be taken away from it. F^or this reason the cupola should be located as convenient to the stock as possible. It must also be borne in mind that the object in constructing a cupola is to obtain fluid molten iron for the work to be cast, and if the cupola is located at so great a distance from the moulding floors that the molten metal loses its fluidity before it can be poured into the mould, the cupola fails in the purpose for which it was constructed. If the work to be cast is heavy and the greater part of the molten metal is handled by traveling or swinging cranes, the small work may be placed near the cupola and the cupola located at one side or end of the foundry near the yard. But if the work is all light hand-ladle or small bull-ladle work, the cupola should be located near the center of the moulding room so that the molten iron may be rapidly conveyed to the moulds in all parts of the room. SCAFFOLD. It is often found diflficult, owing to the shape of the mould- ing room and location of the yard, to place the cupola conve- niently for getting the stock to it and the molten iron away from it. When this is the case, means must be provided for getting the stock to the cupola and the cupola located at a point from (22) CONSTRUCTING A CUPOLA. 23 which the molten metal can be rapidly conveyed to the moulds. At the present low price of wrought iron and steel, a fire proof cupola scaffold can be constructed at a very moderate cost, and the difftculty of locating the cupola convenient to the yard may be overcome by constructing a scafifold of a sufficient size to take the place of a yard for iron and fuel. The scaffold may be constructed under the foundry roof and made of proper size to hold one or two cars of coal or coke, a hundred tons of pig and scrap iron and all the necessary material for a cupola. The space under the scaffold can be utilized as moulding floors for light work or for core benches, core oven, ladle oven, sand- bins, etc. The cupola and its supplies are then under roof, and there is no trouble from cupola men staying at home in bad weather, as is often the case when the cupola and stock are out of doors. When this arrangement is adopted, an endless chain or bucket elevator should be constructed to convey the coal or coke to the scaffold as fast as it is shoveled from the truck or car. Another elevator should be provided for pig and scrap iron, and as the iron is thrown from the car it is broken and at once placed upon the scaffold convenient for melting. This arrangement saves considerable expense for labor in the rehand- ling of iron and fuel, and also prevents the loss of a large amount of iron and fuel annually tramped into the mud in the yard and lost. The saving in labor and stock in a short time will pay the extra expense incurred in constructing this kind of scaffold. CUPOLA FOUNDATION. Too much care cannot be taken in putting in a cupola foun- dation, for the weight of a cupola and stack, when lined with fire-brick to the top, amounts to many tons, and when loaded with fuel and iron for a heat to many tons more. If the foun- dation gives way and the cast-iron cupola bottom is broken by uneven settling, the cupola is rendered practically worthless, for it is impossible to replace the bottom with a new one with- out taking out the entire lining, which entails much expense, 24 THE CUPOLA FURNACE. and it is almost impossible to bolt or brace the plate so as to keep it in place. The foundation should be built of solid stone work, and if a ^ood foundation cannot be had, piles must be driven. Separate stone piers should never be built for each column or post, for they frequently settle unevenly and crack the bottom plate. Uneven settling and breaking oi the bottom are, to a large ex- tent, prevented by placing a heavy cast iron ring upon thi- stone work upon which to set the cupola supports. This ring should be placed several inches below the fioor to prevent it being warped and broken by the heat in the dump. When brick walls are constructed for the support of a cupola, the bottom plate is made square, from two to three inches thick and strongly ribbed or supported by railroad iron be- tween the walls, to prevent breaking. The walls do not admit of sufficient freedom in removing the dump and for this reason are, at the present time, seldom used in the construction of cupolas. Even when the cupola is set so low that a pit is re- quired for the removal of the dump, the iron supports are used and the pit walls built outside of them. When the round cast iron columns are employed, the plate must be made square or with a projection for each column, to admit of the columns being placed at a sufficient distance apart to let the bottom doors swing between them. The best supports for a cupola are the T-shaped posts. They take up less room under the cupola and are less in the way when removing the dump than the round columns, and when slightly curved at the top can be placed at a sufficient distance apart to permit of the drop doors swinging between them. When these posts are used, the bottom j^late is made round and of only a slightly larger diameter than the cupola shell or air chamber, and wdien made of good iron and the foundation plate is used, the bottom plate does not require to be more than i ^ or 2 inches thick for the largest sized cupola. The supports when curved at the top must be bolted to the plate to hold them in place. CONSTRUCTING A CUPOLA. -3 HEIGHT OF CUPOLA BOTTOM. The height the bottom of a cupola or spout should be placed above the moulding floor or gangway depends upon the class of work to be cast. For small hand-ladle work the proper height is i8 to 20 inches; for small bull- and hand-ladle work 24 to 30 inches; and for large crane-ladle work three to five feet. It is very difficult and dangerous to change ladles and catch a large stream from a higl'i cupola in hand-ladles ; and when pieces are only cast occasionally, requiring the use of a large crane-ladle, it is better to place the cupola low and dig a pit in front of it, in which to set the ladle when a large one is re- quired for the work. When the cupola is set low, room must be made for the re- moval of the dump. This may be done by constructing a wall in front of the cupola to keep up the floor under the spout, and lowering the floor under and around the back part of the cupola. When the cupola is so situated that this can not be clone, a pit should be constructed for the removal of the dump. BOTTOM DOORS. Ft)r cupolas of small diameter, but one bottom drop door is used. But when the cupola is of large diameter, the door, if made in one piece, would be so large that there would not be room for it to swing clear of the foundation without setting the cupola too high, and the door would be very heavy and difficult to raise into place. For large cupolas the door is cut in the middle and one-half hung to the bottom on each side. Four and six doors are sometimes used, but they are always in the way when taking out the dump, and require more care in putting in place and supporting. The doors are generally made of cast iron, and vary in thickness from a half inch to an inch and a half, and are fre- quently very heavy and difficult to raise into place. If the doors are large they are much lighter and easier to handle when made of wrought iron, and if properly braced answer the 26 THE CUPOLA FURNACE. purpose equally as well as the stififer cast iron ones. If the lugs on the bottom plate are set well back from the openings and the lugs on the doors made long, the doors drop further away from the heat of the dump, and may be swung back and propped up out of the way when removing the dump. DEVICES FOR KAISING IHE BOIT(JM DOORS. A number of devices have been used for raising the bottom doors of cupolas into place, and thus avoiding the trouble and labor of raising them by hand. One of the oldest of these de- vices is a long bar, one end of which is bolted to the under side of the door; on the other end is cast a weight or ball almost sufficient to balance the door upon its hinges when raised. When the door is down the bar stands up alongside of the cupola, and when it is desired to raise the door the bar and weight are swung downward. As the weight descends the door is balanced upon its hinges and swings up into place^ where it is supported by a prop or other support. This device, when properl)' arranged and in good order, raises the door very easily and quickly into place, but it is continually getting out of order. The sudden dropping of the door in dumping and the consequent sudden upward jerk given to the heavy weight on the end of the bar frequently breaks the bar near the end attached to the door, or breaks the bolts by which the bar is attached to the door, and the door is sometimes broken by the bar. For these reasons this device is very little used. Another device, and probably the best one for raising heav\- doors, is to cast large lugs with a large hole in them, on the bottom and the door, and put in an inch and a half shaft of a sufficient length to have one end extend out a few inches beyon When this occurs the stock has to be dislodged by a long bar worked down through from the charging aperture. If the aperture is placed at too great a height and the lodgment takes place near the bottom, the trouble cannot be remedied with a bar, and melting stops. Cupolas of large diameter may be made of almost any height desired, but there seems to be a limit to the height at which heat is produced in a cupola by the escaping gases, and we have arranged the following table from practical observation, giving the approximate height and size of door for cupolas of different diameters : Diameter Height of Size of Charging Melting Capac :ity Melting Capac Inside Lining, Cupola, Door, per Hour, per Heat, Inches. Feet. Inches. Tons. Tons. i8 6-7 15 X 18 K-^ I — 2 2C 7-8 18 X 20 %-l 2—3 24 8-9 20 X 24 I — 2 3—5 30 9—12 24 X 24 2-5 4 — 10 40 12 — 15 30 X 36 4-S 8—20 50 15—18 30 X 40 6-14 15—40 60 16 — 20 30x45 8—16 25 — 60 The melting capacity of a cupola varies with the kind of fuel' used. One-fourth more iron can be melted per hour with coke than with coal, and the meliing capacity per heat is greatly in- creased by the tapping of slag and the number of tuyeres. CH.'VRGING D(,OR. The charging door may be made in one or two sections and lined with fire brick or daubed with fire-clay; or it may be made of wire gauze placed in an iron frame. The charging door is of but little importance in melting, as it is seldom closed during the greater part of the heat, and is only of service to give draught to the cupola when lighting up, and to prevent sparks being thrown upon the scaffold during the latter part of the heat. .4IR CHAMBER. The air chamber for supplying the tuyeres with blast may be constructed either outside or inside the cupola shell. Wherb 30 THE CUPOLA FURNACE. placed inside, the cupola must be boshed and the lining con- tracted at the bottom to make room for the chamber without enlarging the diameter of the cupola casing. When the cupola is large this can readily be done, and the boshing of the cupola increases its melting capacity ; but small cupolas cannot be contracted at the bottom to a sufficient extent to admit of an air chamber being placed inside without interfering with the dumping of the cupola. When placed inside, the chamber may be formed with cast iron staves made to rest upon the bottom plate at one end and against the casing at the other. The staves are flanged to overlap each other with a putty joint, and when new make a very nice air chamber. But when the lining becomes thin they become heated and frequently warp or break, and permit the blast to escape through the lining to so great an extent that the lining has to be removed and the staves replaced with new ones. The air chamber, when constructed inside the casing, should be made of boiler plate, and securely riveted to the casing to hold it in place and prevent leakage of blast through the lining. It must be constructed of a form to correspond with the bosh- ing of the cupola, and of a size to supply a sufficient quantity of blast to all the tuyeres. If these conditions cannot be met without reducing the cupola below 40 inches diameter at the tuyeres, then the air chamber should be placed on the outside, and any desired boshing of the cupola made by placing com- mon red brick behind the fire-brick lining. When the air chamber is placed upon the outside of the shell, it may be formed by a round cast iron or sheet metal pipe extending around the cupola, with branches extending down to each tuyere ; or it may be made of boiler plate and riveted to the shell. The great objection to the round or over- head air chamber is the numerous joints required in connecting it with each tuyere. These joints require continual looking after to prevent leakage of blast, and in many cases they are not examined from one year's end to another, and a large per cent, of the blast is frequently lost through leaky joints. The CONSTRUCTING A CUPOLA. 3 1 best air chambers are those made of boiler plate and riveted to the cupola shell and securely corked. These air chambers are made of any shape that may suit the fancy of the constructor, and in many cases are very much in the way of the melter in makinglup the cupola, and of the moulders in removing the molten iron. They should not be made to extend out from the shell more than six inches, and any air capacity desired be given by extending the chamber up or down the shell. The air capacity should not be less than three or four times the area of the outlet of the blower, and may be much larger. The blast should be admitted to the chamber from the top on each side of the cupola. This arrangement places the pipes out of the way where the}- are least likely to be knocked and injured. When the tuyeres are placed low, the chamber may be made to extend down to the bottom plate. In this case the bottom plate must be made larger and the chamber cut away front and back for the tap and slag holes. When the tuyeres are placed high, the chamber should be placed up out of the way of the tap and slag holes, and riveted to the shell at both top and bottom. An opening should be made in the air chamber under each tuyere and covered with a piece of sheet lead, so that any molten iron or slag running into the chamber from the tuyeres will flow out and not injure or fill up the chamber. An opening should be placed in front of each tuyere for giving draught to the cupola when lighting up, and for the removal of any iron or slag that may run into the tuyere during a heat. These openings should not be made over three or four inches in diameter, and should each be provided with a tight-fitting door to prevent the escape of the blast. 1 AP HOLE. One or more orifices are placed in the casing at the bottom plate for the removal of the molten iron from the cupola. These openings are known as tap holes, and in the casing are from six to eight inches wide and seven to nine inches high, curved or rounded at the top. The opening through the 32 THK CUPOLA FL'KNACE. cupola lining is generally formed by the brick and presents a very ragged appearance after the lining has been in use a short time. This opening should be lined with a cast iron casting bolted to the cupola casing, and made to extend almost through the lining. The casing should be made slightly taper- ing with the large end inside, or ribbed, to prevent the front being pushed out by the pressure of molten iron retained in the cupola. For small cupolas, or a large cupola from which the iron is removed in large ladles, but one tap hole is required. But large cupolas melting over eight tons of iron per hour, from which the iron is taken in hand-ladles, require two tap holes. Two tap holes are sometimes placed in a cupola on opposite sides to shorten the distance of carrying the iron to the moulds. And two tap holes are also sometimes placed side by side so that each may be kept in better order through- out the heat. This is bad practice, for if the front is properly put in, one tap hole will run ofif all the iron a cupola is capable of melting. When two tap holes are put in they should be placed one in front and the other in the back or side of the cupola, so that the moulders will not be in each other's way when catching-in. THE SPOUT. A short spout must be [)rovided for conveying the molten iron from the tap hole to the ladles. This spout is generally made of cast iron, and is from six to eight inches wide, with sides from three to six inches high, and for small ladle work is from one to two feet long. For large ladle work it is made much longer. In some foundries where a long spout is only occasionally required, the spout is made in two sections and put together with cleats, so that an additional section may be put up to fill a large ladle and taken dovvn when it is filled. The spout should be long enough to throw the stream near the center of the ladle when filling. In a great many foundries the spout is laid upon the bottom plate, and- only held in place by the making-up of the front, and is removed after each heat. CONSTRUCTING A CUPOLA. 33 This entails the loss of a groat deal of spout material each heat, and sometimes the spout is struck in the careless handling of ladles and knocked out of place, when much damage may be done. When not in the way of removing the dump, the spout should be securely bolted to the bottom plate. When it is desired to run a very small cupola for a greater length of time than an hour and a half, or a large one for a longer time than two hours and a-half, slag must be tapped to remove the ash of the fuel and dross of the iron from the cupola, to prevent bridging over and bunging up. The slag hole from which the slag is tapped is placed between the tuyeres, and below the lower level of the lower row of tuyeres. A hole is cut through the casing and lining from three to four inches in diameter, and a short spout or apron is provided to carry the slag out, so that it will fall clear of the bottom plate. The slag hold should be placed at the back of the cupola, or at the greatest possible distance from the tap hole, so that the slag will not be in the way of the moulders when catching the iron. The height at which a slag hole should be placed above the sand bottom depends upon how the iron is tapped. The slag in a cupola drops to the bottom and floats upon the sur- face of the molten metal, and rises and falls with it in the cupola. If the molten iron is held in the cupola until a large body accumulates, the slag hole must be placed high and the slag tapped when it has risen upon the surface of the molten iron to the slag hole. When the iron is withdrawn, the slag remaining in the cupola falls below the slag hole, and the hole must be closed with a bod to prevent the escape of blast. If the iron is drawn from the cupola as fast as melted, the slag hole is placed two or three inches above the sand bottom at the back of the cupola. The slag then lies upon the molten iron, or upon the sand bottom, and the slag hole may be opened as soon as slag has formed, and allowed to remain open throughout the heat. 3 34 THE CUPOLA FURNACE. TUYERES. A number of openings are made through the casing and lin- ing near the bottom of the cupola for admitting the blast into the latter from the air chamber or blast pipe. These open- ings are known as tuyeres. Tuyeres have been designed of all shapes and sizes, and have been placed in cupolas in almost every conceivable position, so there is little to be learned by experimenting with them, and the only things to be considered are the number, shape, size and position of tuyeres for different sized cupolas. For a small cupola, two tuyeres are sufficient. A greater number promotes bridging. They should be placed in the cupola on opposite sides, so that the blast will meet in the center of the cupola, and not be thrown against the lining at any one point with great force. The best shape for a small cupola is a triangular or upright-slot tuyere. These cause less bridging than the flat-slot or oval tuyere, and in small cupolas make but little difference in the amount of fuel required for the bed. When only two tuyeres are provided a belt air chamber around the cupola is not required, and the blast pipes are generally connected direct with each tuyere. In large cupolas the shape of the tuyeres selected makes but little difference in the melting, so long as they are of sufificient size and number to admit the proper amount of blast to the cupola, and so arranged as to distribute it evenly to the stock. The fiat-slot or oval tuyeres are generally selected for the reason that they require less bed than the upright- slot tuyere. The number of tuyeres required varies from four to eight, according to the size of the cupola and tuyeres. They should be of the same size and placed at uniform distances apart. A tuyere should never be placed directly over the tap or slag hole. The combined tuyere area should be from two to three times greater than the area of the blower outlet. The tuyere boxes or casings are made of cast-iron, and should be bolted to the cupola shell to prevent any escape of blast through the lining when it becomes old and shaky, or when lined with poor mate- rial and the grouting works out, as is sometimes the case. CONSTRUCTING A CUPOLA. 35 The height at which tuyeres are placed in cupolas above the sand bottom varies from one or two inches to five feet, and there is a wide difference of opinion among founders as to the height at which they should be placed. When the tuyeres are placed low the iron must be drawn from the cupola as fast as melted, to prevent it running into them. In foundries where the iron is all handled in hand-ladles this can readily be done, and the tuyeres are placed low to reduce the quantity of fuel in the bed and make hot iron. In foundries in which heavy work is cast, and the iron handled in large ladles, the tuyeres are placed high, so that a large amount of iron may be accumulated in the cupola to fill a large ladle for a heavy piece of work. We do not believe in high tuyeres, and claim they should never be placed more than 10 or 12 inches above the sand bottom for any kind of work ; and if slag is not to be tapped from the cupola, they should not be placed more than two or three inches above the sand bottom. In stove foundries, in which cupolas of large diameter are employed and hot iron is required throughout the heat, the tuyeres are placed so low that the sand bottom is made up to within one inch of the bottom of those on the back and two or three inches at the front. This gives plenty of room below the tuyeres for holding iron without danger of it running into them. In cupolas of small diameter two inches is allowed at the back and three or four inches at the front. This insures a hot, even heat through- out the heat, if the cupola is properly charged, and a much less quantity of fuel is required for the bed than if the tuyeres were placed high. Molten iron is never retained in the cupola for this class of work, and the tap hole is made of a size to let the iron out as fast as melted and the stream kept running through- out the heat. Cupolas with high tuyeres are not employed for this class of work, for they do not produce a hot fluid iron throughout a heat without the use of an extraordinarily large per cent, of fuel, and when the tuyeres are extremely high thev do not 36 THE CUPOLA PTTRNACE. make a hot iron with any amount of fuel. Nothing is gained by- holding molten iron in a cupola, for iron can be kept hotter in a ladle than in a cupola, and melted hotter with low than high tuyeres, and a cupola is kept in better melting condition throughout a heat by tapping the iron as fast as melted, TWO OR MORE ROWS OF TUYERES. It is the common practice to place all the tuyeres at the- same level, or in one row extending around the cupola. But two or more rows are frequently placed one above the other^ When a large number of rows are employed they decrease in area gradually from the lower to the top tuyere, and the- rows are generally placed very close together. When two rows are put in, the second row is made from one-half to one- tenth the area of the first row, and the two rows are placed from 8 to 1 8 inches apart. If the area of the second row is one-half that of the first, it is generally placed from 8 to lO' inches above the first row, and only when the tuyeres are very small are they placed at a greater height above the first row. When three rows are put in, the second row is made one-half the area of the first row, and the third row one-fourth the area of the second, and the rows are placed from 6 to lo inches apart. When tu}eres are placed in a cupola all the way up- to the charging door, those above the first or second row are made one inch diameter, and are placed from 12 to 14 inches above each other. The tuyere in the upper row may be placed directly over that in the row beneath it, or may be placed between two lower ones. Some cupola men claim that much better results are obtained by this latter plan, but we have never observed that it made any difference whether they were placed over or between those of the lower rows. Faster melting is secured with two or three rows of tuyeres than with one row in a cupola of the same diameter, and the melting capacity per hour is increased about one-fourth in melting large heats. When melting a small heat for the size CONSTRUCTING A CUPOLA. 37 ■of the cupola, nothing is gained by the additional rows of tuyeres, since a much larger quantity of fuel is required in the bed, for which there is no recompense by saving of fuel in the charges through the heat, and fast melting is seldom any great object in small heats, LINING. The casing may be lined with fire-brick, soapstone or other refractory substances. In localities where fire-brick cannot be ■obtained, native refractory materials are used ; but fire-brick is to be preferred to native mineral substances. Cupola brick is now made of almost any shape or size required in cupola lining, and can be purchased at as reasonable a price as the common straight fire-brick. The curbed btick, laid flat, makes a more compact and durable lining than the wedge-shaped brick set on end, and is most generally used. When laying up a lining, the groutmg or mortar used should be of the same refractory material as the brick, so that it will not burn out and leave crevices between the brick, into which the flame pene- trates and burns away the edges of the brick. This material is jmade into a thin grout, and a thin layer is spread upon the bottom plate. The brick is then taken in the hand, one end dipped in the grout, and laid in the grout upon the plate. When a course or circle has been laid up, the top is slushed with grout to fill up all the cracks and joints, and the next •course is laid up and grouted in the same way. The joints are broken at each course, and the bricks are laid close together to make the crevices between them as small as possible, and pre- vent the flame burning away the corners in case the grouting .material is not good and burns out. Bricks that do not expand when heated are laid close to the •casing. Those that do expand are laid from a fourth of an inch to an inch from the casing, to give room for expansion, and the space is filled in with sand or grout. Brick of un- known properties should always be laid a short distance from the casing, to prevent the latter being burst by expansion of the lining. 38 THE CUPOLA FURNACE. The lining is made of one thickness of brick, and a brick is selected of a size to give the desired thickness of lining. In small cupolas, a four or five-inch lining is used, and in large cupolas a six or nine-inch lining. A heavier lining than nine SECTIONAL VIEW OF CUPOLA. inches is seldom put in, except to reduce the diameter of the cupola or prevent the heating of the shell. In these cases, a filling or false lining of common red brick is put in between the CONSTRUCIING A CUPOLA, 39 fire-brick and shell. The stack lining is seldom made heavier than four inches for any sized cupola, as the wear upon it is not very great, and a four-inch lining lasts for a number of years. The stack lining is laid up and grouted in the same way as the cupola lining. ARRANGEMENT OF BRACKETS, ETC. In Fig. I is shown the manner in which brackets or angle irons are put into a cupola for the support of the lining in sec- tions upon the casing. The brackets are made of heavy boiler plate from five to six inches wide, circled to fit the casing and bent at a square angle. The part riveted to the casing is made four inches long and secured with two or three rivets. The bracket or shelf for the support of the lining is made from one and a half to two inches long. The brackets ire placed about two feet apart around the casing and in rows from two to three feet above each other. These brackets are but little in the way when laying up a lining, and support the latter so that a section may be taken out and replaced without disturbing the re- mainder. Angle iron is by many preferred to brackets for the support of the lining. It is put in bands extending all the way around the casing and riveted to it. These bands not only support the lining but act as braces to the casing, and in some respects are a better support for the lining than brackets. They catch and hold in place all the grouting or sand that may work out of the lining between the casing, and give a more even support to the lining, but with their use it is sometimes more difficult to fit the brick around when laying up a lining. Still, angle iron has generally taken the place of brackets and is put in all the mod- ern cupolas. The brackets or angle irons should not be made to extend out from the casing more than one and a half or two inches, for if they do they are liable to be burned off when the lining becomes thin and let the iron or heat through to the casing. One and a half inches are sufficient to support the lining if the bricks form a circle to fit the casing. No supports 40 THE CUPOLA FURNACE. should be put in at the melting zone, for the lining frequently burns very thin at this point, even in a single heat. It is not necessary to put in any below the melting zone, and the first onis should be placed at the upper edge of the zone, and from this up they should be put in at every two or three feet. The weight of brick placed upon the lower courses in a cupola lining is suflficient to crush most of the soft cupola brick, and were it not for the support given to three sides of them in the lining they would, by the great weight placed upon them, be reduced to a powder. As a lining burns out it becomes thin more rapidly at the bottom, and it often happens that the lining at the melting zone is reduced to one-half its thickness, or even less, in a few heats, and this reduced lining often has to support a lining of almost full thickness for the entire cupola, and in some cases also the stack lining. The cohesive force of these bricks is reduced by the intense heat in the cupola, and when subjected to so great a pressure and heated they are crushed and the lining gradually settles and becomes shaky. This settling is so great with some qualities of brick that in cupolas having no frame riveted to the casing around the charging aperture, the arch over the- door frequently settles so low that it becomes necessary to rebuild it to maintain the full size of the opening. Brick does not give the best results when subjected to so great a pressure and heated to a high temperature. Therefore, in all cupolas, brackets or angle irons should be put in every two or three feet for the support of the lining on the casing, and the latter should be made heavy enough to support the entire lining when a section has been burned out or removed. In the illustration ( Fig. I ) is also shown a way for reducing the size and weight of the bottom doors and preventing the casing from rusting off at the bottom. In many of the large cupolas re- quiring heavy sand bottoms, the bottom plate can be made to extend into the cupola from three to six inches all round witii- out in the least interfering with dumping, and the first few courses of brick sloped back from the edge of the plate to the CONSTRUCTING A CUPOLA, 4 1 regular thickness of lining to prevent sand lodging on the edges of the plate around the lining. By this arrangement in large cupolas, the diameter of the doors may be reduced from six to ten inches, and very much lightened, and less sand will be re- quired, for the sand bottom and the dump fall as freely as when the doors are the full size of the cupola. Cupolas that are not in constant use absorb a great deal of moisture into the lining and are constantly wet around the bottom plate, and ligiit casings are eaten away by rust in a short time. To prevent this the first one or two courses of brick can be laid a few inches from the casing and a small air chamber formed around the cupola at this point. If this chamber is supplied with air from a few small holes through the iron bottom or casing, the latter is kept dry, and rusting is prevented. In the illustration (Fig. i) is shown the triangular-shaped tuyere in position in the lining. This tuyere prevents bridging to a greater extent than any other, and is, for a small cupola, one of the very best shapes. It is formed with a cast iron frame set in the lining, and each tuyere may be connected with a separate pipe, as shown, or they may be connected with an air belt extending around the cupola. Bottom plates may be cast with a light flange around the edge, as shown in the illustration (Fig. i), or made perfectly flat on top ; but it is better to cast them with a small flange or bead for holding the shell in place upon the plate, and thus make the cupola to have a more finished look around the bottom. FIRE PROOF SCAFFOLDS. The charging door or opening through which fuel and iron are charged into a cupola is placed at so great a height from the floor that it is necessary to construct a platform or scaffold, upon which to place the stock, and from which to charge it into the cupola. For heavy work, this scaffold is generally placed on three sides of the cupola, leaving the front clear for 42 THE CUPOLA FURNACE. the swinging of crane ladles to and from the spout; but for light work the scaffold frequently extends all the way around the cupola to give more room for placing stock upon it. I'he distance the floor of a scaffold is generally placed below the charging door is about two feet, but that distance varies, and floors are frequently placed on a level with the door or three or four feet below it to suit the kind of iron to be melted or the facilities for placing stock upon the scafifold from the yard. The scaffold and its supports are more exposed to fire than almost any other part of a foundry, for live sparks are thrown from the charging door upon the scaffold floor, and molten iron, slag, etc., are frequently thrown against its supports and the under side of the door with considerable force when dump- ing the cupola. Numerous plans have been devised to make scaffolds fire-proof and prevent the foundry from being set on fire. In many of the wooden foundry buildings the scafifold is constructed entirely of wood, and to render it fire-proof, the supports and under side of the floor are covered with light sheet iron to protect them from molten iron, slag, etc., when dumping. The covering of the wood-work of a scaffold in this wa}' is very bad practice, for while it protects the wood from direct contact with the fire, it also prevents it from being wetted, and in a short time the wood becomes very dry and very combustible. The thin covering of sheet iron is soon eaten away with rust, leaving holes through which sparks may pass and come in contact with the dry wood and ignite it under the sheet iron where it cannot be seen, and the cupola men, after wetting down the dump very carefully, may go home leaving a smouldering fire concealed by the sheet iron cover- ing which may break forth during the night and destroy the foundry. It is better to leave .all the wood- work entirely un- covered and exposed to the fire and heat, and wet it in exposed places before and after each heat ; the wood is then kept dampened and is not so readily combustible as when covered with sheet iron, and if ignited the fire may be seen and ex- tinguished before the men leave for home after their day's work CONSTRUCTING A CUPOLV. 43 is done. In many of the wooden foundry buildings the cupola is placed outside the foundry building, and a small brick house or room is constructed for it and the molten iron run into the foundry by a cupola spout extending through the wall. In this way a scafifold may be made entirely fire-proof by putting in iron joists and an iron or brick floor, and putting on an iron roof. We saw a scaffold and cupola house at a small foundry in Detroit, Mich., about twenty years ago, that was constructed upon a novel plan and was perfectly fire-proof. The house was twelve feet square and constructed of brick, the scaffold floor was of iron and supported by iron joists, the walls were perpen- dicular to five feet above the scaffold floor, and from this point they were contracted and extended up to a sufficient height to form a stack three feet square at the top. The cupola was placed at one side of this room and the cupola-house, and the spout extended through the wall into the foundry: the open top of the cupola extended about two feet above the scaffold floor, and its stack was formed by the contracted walls of the cupola-house. There were no windows in the house, and only one opening above for placing stock upon the scaffold, and one below for removing the dump and making up the cupola, both of which openings were fitted with iron door frames and doors, and could be tightly closed. When lighting up, the scaffold door was closed to give draught to the cupola, and when burned up the door was opened and the cupola charged from the scaf- fold. Sparks from the cupola when in blast fell upon the scaffold floor and were never thrown from the top of the stack or cupola-house upon the foundry roof or the roofs of adjoining buildings, and when the doors were closed the scaffold was as fire-proof as a brick stack. The great objection to this scaffold was the gas from the cupola upon the scaffold when the blast was on, and the intense heat upon the scaffold in warm weather or when the stock got low in the cupola. The best and safest scaffolds are those constructed entirely of iron, or with brick floors and supported by iron colunms, or brick walls, and made of a sufficient size to admit of wood or 44 THE CUPOLA FURNACE. Other readily combustible cupola material being placed at a safe distance from the cupola. The cupola scaffold in the foundry of Gould & Eberhardt, Newark, N. J., is constructed of iron supported by iron columns and brick walls, and is of sufficient size and strength to carry two car-loads of coke, one hundred tons of pig and scrap iron, and all the wood shavings and other materials required for the cupola. In the new iron foundry building recently erected by The Straight Line Engine Com- pany, Syracuse, N. Y., the scafifold is constructed entirely of iron and supported by the iron columns which support the foundry roof. It extends the entire length of the foundry, affording ample room for storing iron, coke, wood and all cupola sup- plies, thus doing away with a yard for storing such material, and placing them under the foundry roof and convenient for use. Scaffolds of this kind greatly reduce the expense of handling cupola stock, and also reduce the rate of insurance on foundry buildings. CHAPTER IV. CUPOLA TUYERES. The cupola furnace may be supplied with the air required for the combustion of the fuel by natural draft induced by a high stack, a vacuum created by a jet of steam, or by a forced blast from a fan or blower. In either case, the air is generally admitted to the cupola through openings in the sides near the bottom. These openings are known as tuyeres or tuyere holes. The location, size, number and shape of these tuyeres are a matter of prime importance in constructing a cupola, and are a subject to which a great deal of attention has for years been given by eminent and practical foundrymen, and to these men is due the credit for the advancement made in the construction of cupolas. It is only a few years since lO to 15 tons were considered a large heat for a cupola, and when a large casting was to be poured two or more cupolas were run at the same time and the greater part of a day consumed in melting. Now 60 tons are melted in one cupola in four hours for light foundry work, and hundreds of tons are melted in one cupola in steel works without dropping the bottom. This improvement in melting is largely due to the improvement in the size, shape and arrange- ment of tuyeres. There have been epidemics of tuyere-inventing several times in this country in the past twenty-five years, and during these periods it has been almost impossible for an outsider to get a look into a cupola for fear the great secret of melting would be discovered in the shape of the tuyere and made public. Dur- ing these epidemics tuyeres of almost every conceivable shape have been placed in cupolas, and great results in melting, (45) 46 THE CUPOLA FURNACE. claimed for them. Many of these tu>'ere.s were soon found to be compHcated and impracticable, or the advantage gained by their use in mehing was more tiian offset by extravagant use of fuel. It would be useless for us to describe all the tuyeres we have seen employed, for many of them were never used out of the foundry in which they were invented, and there only for a short time. We shall, therefore, describe only a few of those that have been most extensively used or arc in use at the present time. The round tuyere is probably ihe oldest or first tuyere ever placed in a cupola. It was used in cupolas and blast furnaces in colonial days in this country, and long before that in France and other countries. In the old-fashioned cast iron stave cupolas three round tuyeres were generally placed in a row, one above another, on opposite sides of the cupola. The first or lower tuyere was placed from i8 to 24 inches above the sand bottom, and the others directly over it from 3 to 4 inches apart. The tuyere nozzle or elbow was attached to the blast- pipe by a flexible leather hose, and first placed irr the lower tuyere and the two upper tuyeres were temporarily closed with clay. When a small heat was melted the nozzle was permitted to remain in the lower tuyere throughout the heat. But when a large heat was melted and the cupola melted poorly at any part of the heat, or if molten iron was to be collected in the cupola for a large casting, the clay was removed from the upper tuyeres, and the nozzle removed from one to the other, as required, and the lower tuyeres were closed with clay. In these cupolas the tuyeres were generally too small to admit a proper volume of blast to do a good melting. In one of 28 inches diameter we saw at Jamestown, N. Y.. the orig- inal tuyeres were only 3 inches in diameter. Two tuyeres of this size could not possibly admit a sufficient volume of blast to do good melting in a cupola of the above diameter, and in this one they had been replaced by two of a much larger diam- eter placed at a lower level than the old ones. The round CUPOLA TUYt:RES. 47 tuyere is still extensively used in small cupolas where the tuyeres can be made of a diameter not to exceed 5 or 6 inches, but in large cupolas it has generally been replaced by the flat or oval tuyere, which admits the same volume of blast and per- mits of a smaller amount of fuel being used in the bed than could be used with a round tuyere of large area. OVAL TUYERE. In Fig. 2 is shown the oval or oblong tuyere now extensively used. It is made of different sizes to suit the diameter of cupola, the most common sizes used being 2 x 6, 3 x 8. and 4x12 inches. They are laid flat in the lining and generally supplied from an outside belt air chamber. This tuyere is the one most commonly used by stove, bench, and other foundries requiring" very hot iron for their work. They are placed very low, generally not more than two or three inches above the Fil; Fig. 3. CUPOLA TUYERF.S — OVAL TUYERE. EXPANDED TUYERE. sand bottom, and in large cupolas the slope of the bottom fre- quently brings it up to the bottom of the tuyeres on the back side of the cupola. This tuyere admits the blast to a cupola as freely as a rounded one of the same area, and the tendency of the stock to chill over the tuyeres in settling and bridge the cupola is no greater than with a round tuyere of the same capacity. It admits of a lower bed than the round tuyere, and is to be preferred to the latter for cupolas requiring tuy- eres of a larger area. EXPANDED TUYERE. In Fig. 3 is seen the expanded tuyere, which is made larger at the outlet than at the inlet. It is reduced at the inlet so 48 THE CUPOLA FURNACE. that the combined tuyere area may correspond with the outlet of the blower and equalize the volume of blast entering the cupola at each tuyere from the air belt. It is expanded at the outlet to permit the blast to escape freely from the tuyeres into the cupola, and in case the stock settles in the front of the tuyere in such a way as to close up part of it, there may still be sufficient opening for the full volume of blast entering the tuyere to pass into the cupola. The tuyere is made from two to four inches wide at the inlet and six to twelve inches long. The width of the outlet is the same as that of the inlet, and the length of the outlet is from one-fourth to one-half longer than the inlet. The tuyere is laid flat in the lining, the same as the oval tuyere, and the only advantage claimed for it over the latter is that it cannot be closed so readily by the settling of the stock and the chilling of the iron or cinder in front of it. The expanded tuyere is preferred by many to the oval tuyere on this account, and is extensively used at the present time. It has been almost universally adopted by cupola manufac- turers. DOHERTY lUYERE. In Fig. 4 is seen the Doherty arrangement of tuyeres, designed by Mr. Doherty of the late firm of Bement & Doherty, Philadel- phia, Pa., and employed in the Doherty cupola, a cupola that was extensively used in Philadelphia about twenty-five years ago. The arrangement consists of two or more round tuyeres placed in the lining and at an angle to it. instead of passing straight through the lining as tuyeres generally do. The blast pipes connecting with each tuyere were placed at the same angle as the tuyere, the object being to give the blast a whirling or spiral motion in the cupola. The blast took the desired course, as could be plainly seen by its action at the charging door, and it had the appearance of making a more intense heat in the cupola than when delivered from the straight tuyere. But this appearance was deceptive, and after careful investigation it was found that no saving in fuel was efifected, or faster or hotter melting done on account of this motion of the blast. The CUPOLA TUYERES. 49 cupolas and tuyeres were, however, constructed of proper pro- portions, and were a decided improvement on the small tuyere cupolas in use at that time. Many of them were placed in foundries and are still in use, but no importance is attached to the spiral motion of the blast. SHEET BLASr TUYERE. In Fig. 5 is seen the horizontal slot tuyere. This tuyere Fig. 4. Fig. 5. SHEET BLAST TUYERE. OOHERTY TUYERE. consists of a slot from one to two inches wide, extending one- third around the cupola on each side, or a continuous slot ex- tending all the way around the cupola. The slot is formed by two cast-iron plates, on one of which are cast separating bars to prevent the plates being pressed together by the weight of the lining or warped by the heat. This tuyere is known as the sheet blast tuyere. It admits of a smaller amount of fuel being used for a bed than any other tuyere placed in a cupola at the same height above the bottom. It distributes the blast equally to the stock, and does fast and economical melting in short heats. But the tendency of the cupola to bridge is greater than with almost any other tuyere, and a cupola furnished with it cannot be run successfully for a greater length of time than two hours. MACKENZIE TUYERE. In Fig. 6 is seen the Mackenzie tuyere, designed by a Mr. Mackenzie of Newark, N. J., and used in the Mackenzie cupola. This is a continuous slot or sheet blast tuyere, but differs from the one just described in that the cupola is boshed and the bosh 50 THE CUPOLA FURNACE. overhangs the slot from four to six inches. The slot is pro- tected by the overhanging bosh and cannot be closed up by the Fig. 6. MACKENZIE TUVEKE. settling of the stock. The Mackenzie cupola with this tuyere is constructed of an oval or oblong shape, with an inside belt air chamber. The blast enters the air chamber from a tuyere box at each end of the cupola, and passes into the latter through a two-inch slot extending all the way around it. BLAKENEY rUYERK. In Fig. 7 is seen the Blakeney tuyere used in the Blakeney cupola constructed by The M. Steel Company, Springfield, Ohio. This tuyere is a modification or an improvement on the sheet blast tuyere, and extends all the way round the cupola. It is CUPOLA TUYERES. 51 supplied from an outside belt air chamber riveted to the shell. The blast is conducted to the air chamber through one pipe, and, striking the blank spaces sidewise in rear of chamber, passes all around through the curved tuyeres into the centre of the furnace. This tuyere admits the blasts freely and evenly to the cupola and very good melting is done with it. All the tuyeres described above may be used with either coal or coke. HORIZONTAT, AND VERTICAL SLOT TUYERE. In Fig. 8 is seen the horizontal and verticle slot tuyere. This was designed for coke, and we have seen it used in but Fig. 7. BLAKENEY TUYERE. one cupola, a 40-inch one. One tuyere was placed on each side of the cupola. The horizontal slot of each tuyere, i inch Fig. 8. HORIZONTAL AND VERTICAL SLOT TUYERE. wide, e.xtended one-third way round the cupola, and the verticle slots, i inch wide and 12 inches long, were placed above it as shown. The tuyere did excellent melting, and the cupola could be run for a long time without bridging. 52 THE CUPOLA FURNACE, REVERSED T TUYERE. In Fig. 9 is seen a verticle and horizontal slot or reversed "T" tuyere, also used for coke. The slots in this tuyere are from two to three inches wide and ten to twelve inches long. From two to eight of these tuyeres are placed in a cupola, according to the diameter. This tuyere has been extensively used, and is said to be an excellent one for coke-melting. In Figs. lO and ii are seen the vertical slot tuyeres used principally in cupolas of small diameter to prevent bridging. Fig. 9. Fig. 10. Fig II. REVERSED X TUYERE. VERTICAL SLOT TUYERE. VERTICAL SLOT TUYERE They are made from two to three inches wide and ten to twelve inches long, and two or more are placed in a cupola at equal distances apart. TRUESDALE REDUCING lUYERE. In Fig. 12 is seen the Truesdale reducing tuyere designed by Mr. Truesdale of Cincinnati, Ohio, and extensively used in cupolas in that vicinity about 1874. The tuyere consisted of one opening or tuyere placed directly over another until six, eight or ten tuyeres were put in. The lower tuyere was made three or four inches in diameter, and tuyeres above it were placed one inch apart, and each one made of a smaller diam- eter until they were reduced to one inch. The bottom rows of tuyeres were placed two, four or six inches apart, and the tuyeres in each succeeding row were placed further apart, were of a smaller diameter and admitted less blast to the cupola to- CUPOLA TUYERES. 53 ward the top of the bed than at the bottom. The cupolas were generally boshed, and the tuyeres supplied from an inside belt air chamber, formed of cast iron staves, to which the tuyeres were- attached by cleats or dovetails cast on the stays. Very fast melting was done in cupolas with this tuyere, but the ten- dency to bridge in cupolas of small diameter was so great that it could not be used in them. In large cupolas, however, it gave excellent results, and is still in use in numerous foundries. LAWRENCE REDUCING TUYERE. In Fig. 13 is seen the Lawrence reducing tuyere designed by Frank Lawrence of Philadelphia, Pa., and used in the Lawrence cupola, built by him. This tuyere was designed for either coal Fig. 12. O Fk;. 13. Fig. 14. O O o TRUESDALE REDUCINC; TUYERE. TRIANGULAR TUYERE. LAWRENCE REDUCING TUYERE. or coke melting, and works equally well with either. The opening at the bottom is from 3 to 4 inches square, and the slot from 10 to 12 inches long, from i to i^ inches wide at the bottom, and tapers to a point at the top. The tuyeres are placed in the cupola from 6 to 12 inches apart, and supplied from a belt air chamber inside the casing. The air chamber in this cupola was first formed with cast-iron staves, and the tuy- eres were held in place by cleats cast upon the staves. But the 54 THE CUPOLA FURNACE. staves were found to break after repeated heating and cooling, and a boiler-iron casing is now used for the air chamber. This tuyere and cupola do excellent melting, and a great many of them are now in use. TRIANGULAR TUYERE. In Fig. 14 is seen the triangular tuyere, designed by the writer over 25 years ago to prevent bridging in small cupolas, and is extensively used in both small and large cupolas, with either coal or coke. This tuyere may be made with the base and sides of equal length, forming an equilateral triangle, or the sides may be made longer than the base, bringing the tuyere up to a sharp point at the top to prevent bridging; or the sides may be extended up to a sufficient height to form a reducing tuyere. The Magee Furnace Company, Boston, Mass., placed this tuyere in their large cupola, constructed to melt iron for stove plate, about fifteen years ago, and it has been in constant use ever since, giving excellent results in melting with coal and coke. In this cupola, which is 5 feet 4 inches diameter at the melting point, the tuyere is 9 inches wide at the base and 16 inches high. It was not thought best to extend it up to a point at so sharp an angle, and the top was cut off, leaving the opening 2 inches wide at the top. This tuyere has been arranged to take the place of the Truesdale reducing tuyere, and has been made from 6 to 8 inches wide at base and 24 to 30 inches high, running up to a point. It has also been used in imitation of the Lawrence reducing tuyere, and made from 3 to 4 fnches wide at base and 12 to 16 inches high, WATER TUYERE. In Fig. 15 is seen the water tuyere. This tuyere is designed to be used in cupolas or furnaces where the whole or part of the tuyere is exposed to an intense heat and liable to be melted or injured, as is the case with tuyeres placed in the bottom of a cupola or in furnaces where a hot blast is used. CUPOLA TUYERES. 55 The tuyere or metal surrounding the tuyere opening is cast hollow and filled with water, or one end is left open and a spray thrown against the end exposed to the heat from a small pipe, as shown in the illustration. The tuyere is also made with a Fig. i6. Fu;. 15. WATER TUYEKE. COLLIAU TUYERE. coil of gas pipe cast inside of it, through which water constantly flows. The water tuyere is never used when the tuyeres are placed in the sides of the cupola, but it has been used in cupolas in which the tuyere was placed in the bottom and exposed to the heat of molten iron, cinder and slag. When used in this way it is fixed in the centre of the bottom, and is made from i to 3 feet long, the mouth being placed at a sufificient height above the sand bottom to prevent molten iron or slag overflowing into it. The part of the tuyere ex- tending up in the cupola and exposed to the heat is protected and prevented from melting by the stream of water. For this purpose the coil gas pipe tuyere is better than the hollow or spray tuyere just described. 56 THE CUPOLA FURNACE. COLLIAU TUYERE. In Fig, i6 is seen the Colliau double tuyere designed by the late Victor Colliau of Detroit, Michigan, and used in the Colliau cupola. In this cupola the tuyeres are placed in two rows one above the other in place of one row as in the ordinary cupola. The first row is placed at about the same height above the sand bottom as in the ordinary cupola and the second row from 12 to 18 inches above the first row. The first row consists of flat, slightly expanded tuyeres similar to that shown in Fig. 3 ; they are made from 2 to 4 inches wide and 6 to 14 inches long, ac- cording to the size of the cupola. The tuyeres in the second row are made round and from 2 to 4 inches diameter. The tuyeres in the first row pass straight into the cupola through the lining, and those in the second row are pointed downward at a sharp arigle, as shown in the cut. The object of the second row is to furnish suflEicient oxygen to consume the escaping gases and create a more intense heat at the melting point than is obtained with the single row of tuyeres from the same amount of fuel. I WHITING TUYERE. The Whiting tuyere, used in the Whiting cupola, manufac- tured by the Whiting Foundry Equipment Company, Chicago, 111., was designed by Mr. Whiting, a practical foundryman of Detroit, Mich., as an improvement on the Colliau tuyere. The Whiting tuyere is a double tuyere, but dififers somewhat in arrangement from the Colliau. The first row are flat, slightly expanded tuyeres, and the second row are of the same shape and rr)ade larger in proportion to the lower row than the Colliau, and the two rows are not placed at so great a distance apart. Both the upper and lower rows pass straight into the cupola. CHENNEV TUYERE. The Chenney tuyere, designed by the late Mr. Chenney, a practical foundryman of Pittsburg, Pa., is a double tuyere very similar in arrangement to the Colliau and Whiting, the only difference being that both the upper and lower rows point downward at a sharp angle to the lining. CUPOLA TUYERES. 57 THE DOUBLE TUYERE. The double or two rows of tuyeres appears to have first been designed and put into practical use about 1854 by Mr. Ireland, a practical English foundryman and cupola builder. In Ire- land's cupolas, many of which were in use in England about that time, the tuyeres were placed in two rows about 18 inches apart. Those in the upper row were of only one-third the diameter of those in the lower, and twice the number of tuyeres were placed in the upper row as were in the lower. The slag hole was also used by Ireland in his cupola, which was run for a great many hours without dumping or raking out, as was the custom in those days. These cupolas appear to have given very good results in long heats, but in short heats they were not as satisfactory, and in more recent patents obtained by Mr. Ireland the upper row of tuyeres was aban- doned. The double tuyere was also used in Voisin's cupola, another English cupola designer and constructor, and in Woodward's steam jet cupola, also an English cupola, many years before it was introduced into this country by Mr. CoUiau, about 1876. It is claimed for the double tuyere that the second row con- sumes the gases which escape with the single tuyere, and, therefore, a great saving in fuel is effected in melting. That a more intense heat is created in the cupola at the melting zone by the double tuyere cannot be disputed, for the destruction of lining is much greater at this point that with the single tuyere ; but on the other hand, that any saving in fuel is effected has not been proven by comparative tests made in melting with the double tuyere cupola and the single tuyere cupola, when properly constructed and managed. On the contrary it has been proven that the single tuyere cupola is the most econom- ical in fuel and lining. That the double tuyere melts iron faster than the single in cupolas of the same diameter is undisputed, and as between the single and double it is only a question whether the time saved in melting more than compensates for the extra expense of lining. When a double 58 THE CUPOLA FURNACE. tuyere cupola is run to its full capacity, the consumption of fuel per ton of iron is about the same as with the single tuyere, but in small heats it is much greater. This is due to the large amount of fuel required for a bed, owing to the great height of the upper tuyeres above the sand bottom ; for the bed must be made about the same height above the upper tuyeres as above the lower in a single tuyere cupola, and no greater amount of iron can be charged on the bed with the double tuyere than with the single. When constructing or ordering a double tuyere cupola, the smallest one that will do the work should be selected, so that it may be run to its fullest capacity each heat and the best results obtained in melting. THREE ROWS OF TUYERES. A number of large cupolas have been constructed with three rows of tuyeres, for the purpose of doing faster melting than can be done with the single or double tuyere cupola. Prob- ably one of the best melting cupolas of this kind in use at the present time is one constructed by Abendroth Bros., Port Chester, N. Y., to melt iron for stove plate, sinks, soil pipe and plumbers' fittings. This cupola is 54 inches diameter at the tuyeres and 72 inches at the charging door, and is supplied with blast from 36 tuyeres, placed in the cupola in three hori- zontal rows [O inches apart, 12 tuyeres being placed in each row. The tuyeres in the first row are 6 inches square, those in the second row 4 inches square, and those in the third row 2 inches square. This cupola melts 60 tons of iron in four hours, which is probably the fastest melting done in the country for the same number of hours for light work requiring hot iron. In the double or triple tuyere cupola the upper tuyeres maybe be placed directly over a tuyere in the lower row, or they may be placed between the tuyeres of the lower row at a higher level. In Ireland's cupolas double the number of tuyeres were placed in the upper row than were in the lower row, so that one was placed directly over each tuyere in the lower row and one between. In the modern double tuyere cupola the same num- CUPOLA TUYERES. 59 ber of tuyeres are placed in each row, and the upper tuyeres are generally placed between those in the lower row. The object in placing these tuyeres in a cupola, as stated before, is to supply the oxygen to burn the unconsumed gases escaping from the combustion of fuel at the lower tuyeres. If a proper amount of blast is admitted at the lower tuyere the cupola is filled with gases at this point, and it does not make any dififer- ence whether the upper tuyeres are placed over or between the lower ones, so long as they are only to supply oxygen to consume the gases with which the cupola is filled. If this theory of producing heat by consuming the escaping gases from the combustion of fuel is correct, they can be consumed at any point in the cupola, and the row of tuyeres for this pur- pose should be placed above the bed, and the gas burned in the first charge of iron to heat it and prepare it for melting be- fore it settles into the melting zone. To consume these gases only, the tuyeres should be small, and the number of them in the upper rows should be two or three times greater than in the lower row, so as to supply oxygen to all parts of the cupola, and not permit the gases to escape unconsumed between the tuyeres. If the tuyeres in the second and third rows are made too large in proportion to those in the lower row, the supply of oxygen is too great for the combustion of the gases, and the effect is to cool the iron. In the modern double tuyere cupola this theory is not Carried out, for the tuyeres in the second row are made big, and admit such a large volume of oxygen at one point that if they were placed high their efTect would be to cool the iron rather than to heat it. But they are placed low so as to force the blast into the bed and give a deeper melting zone, and their effect is to cause a more rapid combustion of fuel and do faster melting than is done in the single tuyere cupola of the same diameter. GREINER TUYERE. In Fig. \'] is seen the Greiner tuyere. The novelty of this device consists in a judicious admission of blast into the 6o THE CUPOLA FURNACE. Fig. 17. upper zones of a cupola, whereby the combustible gases are consumed within the cupola and the heat utilized to pre-heat the descending charges, thereby effecting a saving in the fuel necessary to melt the iron when it reaches the melting zone. This device consists of a number of upright gas pipes attached to the top of the wind box around the cupola, with branch pipes of I inch diameter extending into the cupola through the lining and about I foot apart, from a short distance above the melting zone to near the charging door. It is claimed that these small pipes admit a sufficient amount of oxy- gen to the cupola to burn the carbonic oxide produced by the carbonic acid formed at the tuyeres absorbing carbon from the fuel in its ascent. A great saving in fuel is thus effected by consuming this gas and pre- paring the iron for melting before it reaches the melting zone. While, when the first edition of this book was published, quite a number of cupolas with this device were in use in this country, the Greiner theory of melting has now been prac- tically abandoned, and we do not know of a single set of these tuyeres being in use at the present time. GREINER TU-YERE. ADJUSTABLE TUYERES. Tuyeres are sometimes placed in a cupola so that they may be adjusted to conform to the size of the heat to be melted or the way the iron is to be drawn from the cupola, and thus save fuel in the bed. They are placed low when the heat is small or the iron is drawn from the cupola as fast as melted, and placed high when the heat is large or when iron is to be held in the cupola for a large piece of work. One of the best arranged cupolas of this kind we have seen is that of the Pennsylvania Diamond Drill and Manufacturing Company, Birdsboro, Pa. CUPOLA TUYERES. 6l The air belt extending around the cupola is riveted to the shell about 4 feet from the bottom plate. From this belt a cast iron air box bolted to the shell extends down nearly to the bottom plate in front of each tuyere. The front of this box has a slid- ing door extending full length of the box. The cupola shell has a slot in front of each box the full length of the box. On each side of this slot a piece of angle iron is riveted to the shell to hold the lining in place. The slot is filled in with fire-brick, and a tuyere opening is left at any desired height from the bottom. When it is desired to lower the tuyere the bricks are removed from the bottom of the tuyere and placed at the top, and held in place by a little stiff daubing or clay, and when it is desired to raise it, the bricks are removed from the top and placed at the bottom when making up the cupola. With the Colliau and Whiting style of air belt an adjustable tuyere can be arranged in this way at a very moderate cost, and foundry- men who think they must have their tuyeres placed high so they can make a large casting and only make such a casting once or twice a year, can save a great deal of fuel from the bed by having their tuyeres arranged in this way. The old plan of putting in two or three tuyere holes one above the other, and adjusting the tuyeres during the heat by raising the tuyere pipe from one to the other, is not practicable with the modern way of charging a cupola, and has long since been abandoned. BOITOM TUYERE. In Fig. 18 is seen the bottom or centre blast tuyere. This tuyere, as will be observed, passes up through the bottom of the cupola instead of through the sides, and admits the blast to the center of the cupola at the same level as the side tuyeres. It is not designed to change the nature of the iron by forcing the blast through the molten iron in the bottom of the cupola, and, in fact, the blast has no more efTect upon the quality of iron when admitted in this way than when admitted through side tuyeres. A tuyere when placed in the bottom of a cupola, unlike a side tuyere, is brought in direct contact 62 THE CUPOLA FURNACE. with heated fuel and molten iron, and it must be made of a refractory material, or protected by a refractory material if made of metal. The tuyere shown in the cut is made of cast iron and is provided with a water space between the outside and the inside, through which a stream of water constantly flows, when the tuyere is in use, from a small pipe connected with a tank placed alongside the cupola or on the scafTold. But it has not been found necessary to Iceep the tu}'ere cool with water in short heats, for the heat in a cupola under the tuyeres BOTTOM TUYERE. is not sufficiently intense to melt cast iron, and the tuyere may be sufficiently protected against molten iron dropping upon it of coming in contact with it by a thick daubing of refractory material held in place by the prickers cast on the tuyere. The mouth of a bottom tuyere must be covered to prevent molten iron, slag and fuel dropping into it in their descent to the bottom of the cupola. This is done with a rounded cap placed on top of the tuyere to throw ofif the molten iron and slag, and the blast is admitted to the cupola through an opening around CUPOLA TUYERES. 63 the tuyere under the cap, as indicated by the arrows. The tuyere must be carefully dried and daubed before it is put in place. It cannot be attached to the bottom doors and must be put in place through a hole in the doors after they are put up, and withdrawn in the same way and removed before the cupola is dumped, to prevent it being broken or injured in falling or by the heat in the dump. It must have an adjustable and re- movable support, and the sand bottom must be made up very carefully around it to prevent leakage of molten iron. The tuyere often gets fast in the bottom and the men are frequently burned in removing it, and it sometimes gets filled with iron or slag, and spoils a heat. The bottom tuyere has been tried a great many times by foundrymen at different periods, and is nothing new. In con- versing with several old foundrymen in Massachusetts about 20 years ago, we learned that the bottom tuyere has been used in that State away back in the 40's, and at one time was quite popular with foundrymen there ; and we have met a number of other old foundrymen in different sections of the country who had tried the tuyere years ago and given it up. A bottom tuyere was patented by B. H. Hibler in this country August 13, 1867. Ireland and Voisin used a bottom tuyere in their cupolas many years ago, and had these practical men found any advantages in it over the side tuyere it would, no doubt, have been brought into general use in cupolas before this. The bottom tuyere was brought prominently before the foundrymen of this country by an ably written article by Thomas D. West, read before the Western Foundrymen's Association at Chicago, 111., October 18, 1893, in which he describes his experiments with the tuyere and claims for it a great saving in fuel and cupola lining. Since the publication of Mr. West's article a nimiber of foundrymen have published their experience with the tuyere and all claim it effects a great saving in lining and fuel. But if these foundrymen have not discovered some new feature in the tuyere that was overlooked by experimenters with it years ago, it will never come into general use. 64 THE CUPOLA FURNACE. Since the publication of the above in the first edition of this work, the bottom tuyere has been extensively tried by practical foundrymen and by cupola manufacturers who have constructed a variety of bottom tuyere devices, all of which were designed to obviate the difificulty of placing the tuyere in position, main- taining it there, removing it after a heat, and preventing molten iron and slag getting into it. So far as we have been able to learn all of these devices have been failures to so great an extent that the use of this tuyere has been practically abandoned; very few, if any, of them are being used at the present time. SIZE OF TUYERES. Foundrymen make a great mistake in placing small tuyeres in their cupolas, with a view of putting the blast into the cupola with greater force and driving it to the center of the cupola with the blower. Air may be driven from a small opening by a blower with greater velocity than the same vol- ume of air from a large opening, but the air from a small opening loses its velocity when it strikes a solid body, just the same as the air from a large opening. When the blast from a small tuyere strikes the solid fuel in front of it, its velocity is gone and it will not penetrate any further into the stock than the same volume of blast from a large tuyere. It is not the velocity at which the blast passes into a cupola that drives it to the center, but the force behind the blast. Neither is it the velocity of the blast that does the melting. It is the volume of blast. It therefore follows that nothing is gained in melting by forcing the blast through a small tuyere into a cupola with great velocity, and much is lost by increasing the power re- quired to run the blower to force the blast through a small tuyere. The small tuyere was one of the greatest mistakes made in the old-fashioned stave cupola. In these cupolas, many of which we have seen, only two tuyeres of 3 or 4 inches diameter were placed in a 30-inch cupola, and the improvement made in CUPOLA TUYERES. ^ 65 melting in the modern cupola is largely due to the enlarge- ment of the tuyeres and the free admission of blast to the cupola. The combined tuyere area of a cupola should be equal to three times the area of the outlet of the blower when the blower is of a proper size for the cupola. These dimensions may at first sight seem large, but it must be remembered that the size or area of a tuyere when a cupola is not in blast does not represent the area of the tuyere when a cupola is in blast, or the volume of blast that may be admitted to the cupola by the tuyere. When a cupola is in blast the space in front of the tuyere is filled with fuel weighted down with tons of iron. This fuel closes the mouth of the tuyere, and the outlet is rep- resented by the number of crevices between the pieces of fuel through which the blast may escape. Should a large piece of fuel fall in front of a tuyere the blast cannot remove it and the tuyere may be closed and rendered useless. Small tuyeres are more liable to be closed in this way than large ones, and for this reason they should never be placed in a cupola. Small tuyeres, furthermore, are not only more liable to be stopped ofT by the fuel, but also tend to promote bridging by admitting an insufficient amount of blast at certain points. HEIGHT OF TUYERE. There is a wide difference of opinion among foundrymen as to the height or distance tuyeres should be placed in a cupola above the sand bottom. So great is this difference of opinion at the present time that tuyeres are placed in cupolas at from 2 inches to 5 feet above the sand bottom. This wide variation in the height of tuyeres is due to some extent to the different classes of work done in different foundries, it being claimed by foundrymen making heavy work that it is necessary to have the tuyeres high to hold molten iron in the cupola and keep it hot for a large casting. Foundrymen making light castings requiring very hot iron draw the iron as fast as melted, and do not think it necessary to have high tuyeres to hold iron in the 5 66 THE CUPOLA FURNACE. cupola. In the many experiments we have made in melting iron in a cupola, we have placed the tuyeres at various distances above the sand bottom, and closely observed the effect of them at different heights. We learned by these experiments that the fuel under the tuyeres it not consumed in melting, nor is it wasted away to any extent by the heat or molten iron coming in contact with it. Charcoal may be placed in the bottom of a cupola, and if care is taken to prevent its being consumed by admission of air through the front before the blast is put on, the charcoal will not be consumed during the heat and may be found in the dump. We have tried this in our experiments to soften hard iron by bringing the molten metal in contact with charcoal in the bottom of a cupola, and found it correct. Pieces of charred wood used in lighting up are often found in the dump after having remained in the cupola throughout a heat. If these soft combustible substances are not consumed under the tuyeres, then it is not at all likely that the less combustible hard coal and coke are consumed. No iron can be melted in a cupola under the tuyeres, and the only function of the fuel below the tuyeres is to support the stock in a cupola above the tuyeres. If there is not sufficient heat in the bottom of a cupola to consume wood or charcoal, then there is not sufficient heat to keep molten iron hot for any length of time ; and it is a well-known fact among practical foundrymen that large bodies of molten iron can be kept hot and fluid for a greater length of time in a ladle when covered with charcoal to exclude the air than they can be in a cupola. Another reason given in favor of high tuyeres is that it is necessary to have them high to tap slag in long heats. The only slag in a cupola that can be drawn through a slag hole is a light fluid slag and floats on top of the molten iron or rests on the bottom of the cupola when there is no molten iron in it, and this slag may be drawn at any point between the sand bottom and tuyere. When a slag hole is placed high, slag only can be drawn when the cupola is permitted to fill up with molten iron and raise the slag upon its surface to the slag hole. CUPOLA TUYERES. 67 Slag may then be drawn for a few minutes while the cupola is filling up with iron to the slag hole. As soon as the iron reaches the slag hole, however, it flows out and must be tapped from the front. This slag then falls in the cupola with the sur- face of the iron as it is drawn ofT, and the slag hole must be closed to prevent the escape of blast through it. Iron tapped after permitting a cupola to fill up to a high slag hole is always dull. When a slag hole is placed low it is not necessary to have the cupola fill up with iron before slag can be tapped, for the slag may be drawn ofif the bottom of the cupola, and, further- more, the slag hole may be opened and permitted to remain open throughout a heat without waste of blast. The flow of slag regulates itself when the hole is of proper size. It is, there- fore, not necessary to place tuyeres high that slag may be drawn from a cupola, nor is it necessary to hold iron in a cupola for a large casting or to keep it hot. Molten iron should be handled in a ladle and not in a cupola. Hot iron for light work cannot be made in cupolas with high tuyeres, and for this reason the tuyeres in stove-foundry cupo- las are always placed low. In cupolas of large diameter, hav- ing a large bottom surface for molten iron, the tuyeres are placed so low that those at the back of the cupola are not more than i inch above the sand bottom, and those in front not more than 2 or 2J^ inches above the sand bottom. Tuyeres placed in this way give ample space below them to hold molten iron for this kind of work, for the iron must be very hot and is drawn from the cupola as fast as melted, and the cupola is large enough to melt iron as fast as it can be handled, and it is only when the cupola is not working free that it is stopped up to accumulate iron. The tuyeres in any cupola may be placed as low as in these large ones, if provision be made for handling the iron as fast as melted. In smaller cupolas not capable of melting iron sufficiently fast to fill a 40-pound hand-ladle, every 8 or 10 seconds the tuyeres are placed from 2 to 4 inches above the sand bottom, 6S THE CUPOLA FURNACE. SO that a sufficient quantity of iron may be collected before tapping to give each man in the section catching a hand-ladle full, and fill the ladle in about 6 seconds. In cupolas of very small diameter the tuyeres should be placed from 6 to lO inches above the sand bottom. These very small cupolas melt so slow that if the iron is drawn as fast as- melted the stream is so small that the iron is chilled in flowing: from the cupola to the ladle more than it is by holding it in. the cupola until a body of iron is collected sufficient to supply a large stream. In machine and jobbing foundry cupolas tuyeres are gen- erally placed from i8 to 24 inches above the sand bottom^ The object in placing the tuyeres so high is to hold iron in the cupola for a large casting. But, as before explained, this is not necessary or advisable. Another reason for these high tuyeres IS that they are necessary for tapping slag. The slag from many cupolas is drawn off at the tap hole with the iron, and a number of spouts have been invented for separating the slag: from the iron and preventing it running into the ladle. Slag may be drawn from the back of a cupola on a level with the sand bottom at that point, if the iron is drawn as fast as melted^ or it may be drawn i, 2 or more inches above the sand bottom at that point. It is, therefore, not necessary to place tuyeres at so great a height to tap slag. The tuyeres in cupolas for heavy work should be placed from 6 to 8 inches above the sand bottom when slag is not to be tapped. This gives an abundance of room in a cupola for "holding iron while removing or placing a large ladle, and that is all that is necessary. The tuyeres in many of the cupolas used in Bessemer steel works are placed five feet above the bottom. They are probably placed at so great a height be- cause the tuyeres in the first cupola constructed for this work were placed at that height. Tuyeres in all cupolas should be placed as low as they can be for the size of the cupola and facilities for handling the iron, for the fuel placed in a cupola under the tuyeres is not consumed in melting and is wasted by CUPOLA TUYERES. 69 being heated in the cupola and crushed and burned in the dump. The vakie of fuel wasted every year in the United States by the use of high tuyeres in cupolas is sufficient to make a man rich. NUMBER OF TUYERES. A cupola may be supplied with blast from one tuyere placed on one side of the cupola, but the objection to one tuyere arranged in this way is that the heat is driven by the blast against the opposite side of the cupola, and the destruction of lining at this point is very great. For this reason, at least two tuyeres are always placed in a cupola, and they are located on opposite sides so that the blast will meet in the center and be diffused throughout the stock. When a greater number of tuyeres than two are placed in a cupola they are located opposite •each other and at equal distances apart, to admit an equal amount of blast on all sides and prevent an uneven destruction of lining from the heat being forced unevenly against it by the blast. Any number of tuyeres desired may be placed in a cupola, and as high as 100 have been used in a 40-inch cupola, and a greater number in larger cupolas. But these large num- bers have given no better results in melting than two or four tuyeres in the same cupolas. It is not necessary to place a large number of small tuyeres in a cupola to distribute the blast €venly to the bed, and it is not advisable to put in small tuyeres, which are easily closed by the fuel, cinder and iron, and are oftener rendered useless than large ones. Better results are obtained from large tuyeres and fewer of them. The largest cupola in use may be supplied with blast by two tuyeres if they are big enough. The large cupola of the Buffalo School Furniture Company, Buffalo, N. Y., is supplied with blast by two tuyeres 12x18 inches, placed on opposite sides. The cupola, which is 60 inches in diameter inside, does excellent melting with only these two tuyeres, and the destruc- tion of hning in melting is very light. We saw a large cupola with two tuyeres of about the above dimensions in use in a 70 THE CUPOLA FURNACE. Stove foundry in St. Louis, Mo., about 20 years ago, and it did excellent melting. The results obtained from these two cupolas would go to show that there is nothing gained in dis- tributing the blast to the bed evenly by a large number of small tuyeres. When a number of tuyeres are placed in one row, every other tuyere is sometimes placed about the width of the tuyeres higher than those on either side of it. We have, however, never observed that anything was gained in melting by placing tuyeres in this way. When a double row of them is used the upper row should be made very small in comparison with the lower row, for if they are made of the same size as the lower one, or even half the size, and the two rows are placed at any great distance apart, the heat is so con- centrated upon the lining between them that it may be burned out to the casing in one or two heats. Foundrymen using the double tuyeres, who find the destruction of lining very great, may prevent it to some extent by reducing the size of the upper tuyeres. SHAPE OF TUYERES. The shape of a tuyere has nothing to do with the melting, except as it may tend to prevent bridging or increase the depth of the melting zone by supplying blast to the fuel at different heights in a cupola. A small horizontal slot tuyere extending around a cupola, or the greater part of the way around it, tends to promote bridging, and it is generally conceded that a cupola with a tuyere of this kind cannot be run for a greater length of time than two hours without bridging and clogging up. Vertical slot and reducing tuyeres supply blast to the bed at different levels and increase the depth of the melting zone the same as the double tuyere. For this purpose the Truesdale, Lawrence and triangular tuyeres, with elongated sides, are excellent when made of a proper size and placed a proper distance apart. When it is not desired to admit the blast to the bed at different levels, the flat or oval tuyeres are generally considered the best shapes, for they admit the blast freely, and a less amount of CUPOLA TUYERES. J I fuel is required for a bed with these shapes than with a round or square tuyere of the same area. TUYERES TO IMPROVE THE QUALITY OF IRON. All kinds of fancy shaped tuyeres have been placed in cupolas to improve or change the quality of iron in melting. They have been placed to point up, point down, point across each other at certain angles, and to point to the centre of the cupola. There is nothing more absurd than to attempt to improve the quality of iron in a cupola by the shape or angle of the tuyers. The instant the blast leaves the mouth of a tuyere it strikes the fuel in front of it. The shape or angle given to it by the tuyere is then instantly changed, and it passes through the crevices in the fuel until its oxygen enters into combination with the carbon of the fuel and produces combus- tion. It then escapes at the top of the melting zone, where it comes in contact with the iron as carbonic acid gas. This is the result, no matter what the shape or angle of the tuyeres, if a proper amount of blast is supplied. It may be claimed that the blast acts upon the iron as it drops through the fuel in the bed after being melted ; but as before stated, the shape or angle given to the blast by the tuyeres is changed by the fuel, and the effect on the iron of the blast from one tuyere would be the same as from another. TUYERE BOXES. The tuyeres may be and are often formed in the lining of a cupola when laying the brick, but this is a very poor way of making tuyeres, for there is nothing to support the brick and maintain the shape of the tuyeres, and they are often broken or burned away until there is no regular shape to the aperture,, and it is difficult to put the blast into the cupola at the point desired or to prevent iron or slag getting into the tuyere. Tuy- eres are more generally formed with a cast iron. lining or tuyere box, having the shape and size of tuyere desired. This box may be cast with a flange on one end and be bolted to the cas- 72 THE CUPOLA FURNACE. ing, or it may be cast without a flange and placed in the lining at the desired point as it is laid up. The boxes are made in both ways, but it is better to cast them with a flange and bolt them to the casing, making an air-tight joint, as it then insures the blast going directly into the cupola at the point desired. Tuyere boxes laid in a lining answer the purpose very well when the lining is new, but when it becomes old and shaky, or a section is removed and replaced, the lining often settles and the grout- ing or filling falls out, leaving crevices through which the blast escapes between the casing and lining, and from there enters the cupola at points where it does no good. The cold blast supplied to a cupola keeps the tuyere box cool, and it is not necessary to cast it hollow and fill it with water to prevent it being melted or injured by the heat. The only part of the box that is exposed and liable to be injured is the end next the fire, and to protect it the box at this point is generally cast about yi inch shorter than the thickness of the lining and the end covered with a little clay or daubing. NEW TUYERES. Since the publication of the second edition of this work, three new designs of tuyeres have been patented and installed in cupolas with marked improvement in melting in some cases and complete failure in others. The success in some instances, and failure in others, was in many cases no doubt due to the dififerent pressures or volume of blast furnished the cupola. But in other cases it was doubtless due to the patentee mak- ing too extravagant claims for his tuyere in the saving of fuel, fast melting, clean drop, etc., results he was not able to demonstrate, in well managed cupolas. Tuyeres are not the only factor in successful cupola practice, and for this reason the enthusiastic new tuyere patentee or designer should learn what results are being obtained from the cupola and compare them with results he has obtained in other cupolas, and if the com- parison does not show a chance for a decided improvement in favor of his tuyere, he will save himself considerable time and CUPOLA TUYERES. 73 money by not placing it in the cupola. The same policy should be followed by the founder to insure him against loss from bad heals that are almost certain to result in case of failure. THE WAIT CUTOLA TUYERES. The Watt cupola tuyere was designed by Mr. Watt, founder of the Watt Mining Car Wheel Company of Barnesville, Ohio, for use in the cupolas of their plant, and it gave such excellent results in melting and clean drop that Mr. Watt was induced to obtain a patent on the tuyere and formed The Watt Cupola Tuyere Co., to place the tuyere upon the market. This tuyere, as will be seen in the illustration. Fig. 19, is a belt tuyere ex- FiG. 19. Fig. 20. tending around the cupola, the front of which is covered with lattice-work plates, thus presenting an entirely new feature in tuyere construction. The other illustrations show the various parts used in the tuyere. Fig. 20 represents the belt air chamber, which is cast in sections and placed inside the cupola shell in the lining. Openings are provided in the backs of these sections for admissions of blast from the outside belt air chamber of the cupola to the inner chamber, and the size of tuyeres for cupolas of various diameters are regulated by the depth or width of this air chamber. Fig. 21 shows a section 74 THE CUPOLA FURNACE. Vv^ith tuyere plates attached so as to come flushed with the cupola lining. Fig. 22 shows the tuyere plates with hooks cast upon them for attaching to the air chamber and admitting of their removal in case iron or slag gets into the tuyere. This Fig. 21. tuyere, which gave every promise of success from the excellent results obtained in the Watt plant, was placed by The Watt Cupola Tuyere Co. in many cupolas throughout the country with excellent results in melting in many cases, but in others it failed to give even as good results as that obtained from the one which it replaced. This was no doubt due to the outlet area of the tuyere being much greater than that of the one it replaced and, the volume of blast not being sufiticient FiGr 22. to supply the tuyere with air for an equal distribution. Fail- ures was also no doubt due in some instances to too great a claim being made for the tuyere in saving of fuel hot iron, fast melting, etc. ; a mistake frequently made by tuyere designers. CUPOLA TUYERES. 75 IHE ZIPPLER TUYERE. In Fig. 23 is shown the Zippier tuyere. This tuyere was designed by the late Michael Zippier, an old melter of Pitts- burg, Pa., and installed in a number of cupolas 25 to 30 years ago with good results in many cases. But the shape of lining required for the tuyere was difficult to maintain, and the tuyere never came into general use. A few years ago Mr. Zippier improved it by adding a second row of tuyeres and the Fi<;. 2.^ THE ZIPl'LER TUYKRE. use of metal blocks around the tuyeres, which supported the over-hanging lining and made it more stable and readily maintained in its original shape. Since this improvement, for which he obtained a patent, the tuyere has been installed in a number of large cupolas with excellent results. But, like all others, it has failed in a number of instances to produce hotter iron or do faster or more economical melting than the one in use before its installation. THE KNOEPPEL TUYERE. In Fig. 24 may be seen the Knoeppel system of cupola tuyeres, designed and patented by John C. Knoeppel, a prac- tical foundryman of Buffalo, N. Y. The tuyeres embrace the 76 THE CUPOLA FURNACE. same principles as the Zippier tuyere, namely the overhanging bosh, and only differs from it in a third row being added and the upper rows being made smaller than the Zippier. This tuyere has been installed in a number of large cupolas with marked improvement in melting and saving of fuel, and is an excellent tuyere for large cupolas in which it is desired to hold molten iron. Neither of these tuyeres present any new Vh,. 24. THE KNOEPPEL TUYERE. features in cupola construction or tuyere arrangement for, as will be seen by reference to Fig. 64, the overhanging bosh and double row of tuyeres were designed and patented by Mr. Ireland, an English cupola inventor in 1856, and the over- hanging bosh may also be seen in the illustration of a number of other English cupolas in use about that time. But this feature was abandoned later on, and cupolas were constructed with straight linings, or boshed from the bottom plate to the desired height above the tuyeres. CHAPTER V. CUPOLA MANAGEMENT. The peculiarities in the working of every cupola must be learned before it can be run successfully, and this can only be done by working it in different ways. It is a question very much disputed whether a cupola constructed upon the latest improved or patented design is superior to one of the old style. This question can only be decided by the intelligent working of each cupola, and the advantage will always be found in favor of the one that is properly worked, no matter what its con- struction. It is the duty of every foundryman to give his per- sonal attention to the working of his cupola if he has time. If he is not a practical founder or has not the time to devote to this branch of the business that it requires, then he should have his foundry foreman give it his personal attention for a sufficient length of time each day to see that everything is right in and about the cupola. No cupola can be run successfully by any given rule or set of rules, for conditions arise to which the rules do not apply. We shall therefore not only give directions for the proper working of a cupola at every point, but shall also give the re- sults or effect of bad working at every point, so that the founder when he finds his cupola is not operating well may have some data from which to draw conclusions and be able to overcome the difficulty. DRYING THE LINING. The cupola having been newly lined, nothing is to be done to the lining for the first heat but to dry it. A very high or prolonged heat is not required for this when only one thick- ness of brick is put in and laid up in thin grout. The lining {77) 78 THE CUPOLA FURNACE. may be dried by making a wood fire after the sand bottom is put in, or by starting the fire for the heat a little sooner than usual. But the fire must not be started too early or the bed will be burned too much and the cupola filled with ashes, which will retard the melting. When a backing or filling of wet clay or sand several inches thick is put in between the casing and lining, more time and care are required in drying. It must then be dried slowly and evenly, or the filling will crack, and when jarred in chipping out will crumble and work out through cracks in the lining or holes in the casing and leave cavities behind the lining. When a lining is put in in this way, the doors are put up and covered with sand and a good coal or coke fire is made in the cupola and allowed to remain in over night. In the morning the bottom is dropped to remove the ashes and cool ofif the lining before making up the sand bottom for a heat. PUrriNG UP THE DOORS. The first thing to be done when making up the cupola for a heat is to put up the bottom doors. When the cupola is of small diameter and the door light, it may be raised into place and supported by one man. But when the door is heavy two men are required, aud if the cupola is a large one and the door made in two parts, three men are required to lift and support them. Two men get inside the cupola and raise one-half into place while the third man supports it with a temporary prop ; they then raise the other half as far as it can be raised with their bodies between the two doors, where it is supported by a temporary prop. The men then get under the door on their hands and knees and raise it into place on their backs, and it is then supported by a prop. Numerous devices have been arranged for raising the doors into place, but they soon get out of order from the heat of the dump or carelessness in manipulation, and they have almost all been abandoned. When the cupola is very small and the door light, it is sometimes supported by an iron bolt attached to the CUPOLA MANAGEMENT. 79 under side of the bottom plate at the front, where it can be readily withdrawn with an iron hook to drop the bottom. But the doors are generally supported by a stout iron prop or post placed under the door near the edge opposite the hinges. Double doors are supported by a stout iron prop in the center and generally a light one at each end of the doors to prevent them springing when charging the fuel and iron, or by a sudden settling of the stock, as may occur when melting large chunks. A great many melters have no permanent foundation under the cupola upon which to place the main prop, but make one every heat by laying down a small plate upon the sand and setting the prop upon it. The plate is often placed too high or too low, making the prop too long or too short, and the plate must be raised by putting a little more sand under it or lowered by scraping away a little sand. When this is being done the heavy iron prop, which frequently requires two men to handle in the cramped position in which they are placed under the cupola, has often to be put up and taken down two or three times before it is gotten into the right position to support the doors. All this extra labor can be avoided and time saved by im- bedding a heavy cast-iron block in the floor or foundation under the cupola for the prop to rest upon. It must extend down a sufficient distance to insure its not being disturbed when shoveling out the dump. A block 6 inches square and 10 inches long, placed with the end level with the floor, will seldom be displaced, and makes a sure foundation for the prop. The size of prop required to support a bottom depends upon the size of cupola. In small cupolas the stock is supported to a large extent by pressure against the lining, while in large cupolas the stock is supported almost entirely by the prop. For small cupolas the props are made from i ^ to 2 inches diameter, and for large cupolas from 3 to 3^ inches diameter. The props for large cupolas not only have a greater weight to support, but they are seldom pulled out of the dump and are therefore, if light, liable to be bent and twisted to such an 8o THE CUPOLA FURNACE. extent as to render them useless. For this reason they are often made heavier than is actually necessary for the support of the bottom. Quite a number of foundrymen have adopted the plan of attaching a ring to the prop near the top or bottom with which to draw it from the dump and avoid heating it. The ring is made large and hangs loosely, or as a long loop which stands out from the prop. When the prop is to be removed a hook is placed in the ring or loop and a quick jerk given, which releases it, and it is at once drawn from under the cupola. Some of the older melters never use the iron prop, but measure and cut a new wood prop for their cupola every heat. Many of them are so superstitious that they think the cupola would not melt without the new prop, and they would rather give up their jobs than try it. Such melters are not so plenti- ful now as they were 30 years ago, when we first began travel- ing as a melter through this country and Canada, but we find when visiting foundries there are still a few of them left. DROPPING THE DOORS. When it is desired to drop the doors it is done by removing the props or drawing the bolt. The small props are first taken out, being released by a stroke of the hammer, and are care- fully laid away so that they will not be bent by the heat of the dump. A long bar with a handle on one end and a large hook on the other is then placed under the cupola with the hook be- hind the main prop and about 10 or 12 inches from it. By a sudden jerk of the bar the hook is made to strike the bottom of the prop a sufficiently hard blow to knock it out of place and permit the door or doors to drop. Two or more blows of the bar are sometimes necessary to release the prop, but it can always be released in this way. It can also be released by striking it at the top with a straight bar, but it is oftener missed than hit, and many thrusts are sometimes required to bring it down. Bolts are only used on small cupolas from which the dump falls slowly, and the bolt can generally be with- CUPOLA MANAGEMENT. 8 I drawn by a blow of the hammer without danger to the melter. If it cannot be withdrawn in this way without danger of burn- ing the melter, a hook is made on the end of the bolt or a ring placed in it so that it may be drawn with a hooked bar or struck with a long straight bar. SAND BOTTOM. When the door or doors are in place and properly sup- ported, any openings or holes that may have been burned through them are carefully covered with a thin plate of iron, and all cracks through which the bottom sand might escape when dry are closed with clay. The doors are then covered with a bed of sand several inches in thickness, which is known as the sand bottom. The sand employed for this purpose must not be of a quality that will burn away and permit the molten iron to get down to the doors, or melt and form a hard mass that will not fall from the cupola when the doors are dropped, neither must it be so friable as to permit the molten iron to run through it when dry. The clay sands when used for a bottom burn into a hard, tough mass that adheres to the lining all around the- cupola, and in a small cupola frequently remains in place after the door is dropped and has to be dug out with a bar before the cupola can be dumped. Parting sand, sharp and fire sands are very friable and difficult to keep in place. They do not resist the action of the molten iron well, but melt and form a slag. Mixtures of clay and sharp sand burn too hard and do not drop well. The loam sands are the only ones suitable for a sand bottom, and sand that has been burned to a limited extent makes a better bottom than new sand. In stove and other foundries with large gangway floors the scrapings from the gangways are collected in front of the" cupola, passed through a No. 2 riddle to recover the scrap iron, and the sand used for the cupola bottom. This sand makes the very best kind of bottom. It is clean and free from cinder, soft and pliable, packs close, resists the action of the 6 82 THE CUPOLA FURNACE. molten iron and drops free. In foundries where the daily gangway cleanings are not sufficient to make the bottom, part of the old bottom is used over and the gangway cleanings are mixed with it or placed on top. In foundries where there are no regular gangways to clean every day, the heavy part of the dump is thrown out and the sand bottom passed through a No. 2 riddle and used over again. When the bottom sand is used over day after day, it must not be riddled out too close, and a little fresh material must be added to it each day to prevent it from becoming rotten from repeated burnings and containing too many small particles of cinder, which render it fusible and easily cut away by the molten iron. The cleanings from the moulding floors are generally added or a few shovelfuls from the sand heaps, and in case it becomes too rotten a few shovel- fuls of new moulding sand are mixed with it. When the material contains so much cinder that it does not make a smooth bottom, a few shovelfuls of burned sand from the heaps are put on to give an even surface and prevent the molten iron from coming in contact with the cinder and cutting the bottom. The bottom sand is generally wet with water, but some melters wet it with clay wash, to make it more adhesive and give it more strength to resist the action of the molten iron. A thick clay wash gives strength to a rotten sand when mixed with it, but it also increases the tendency of the bottom to cake and hang up, and it is better to improve the bottom material in the way above described and wet it with water only. The sand when wet is cut over and evenly tempered, and should be no wetter than moulding sand when tempered for a mould. The sand may be thrown into the cupola through the front opening, or may be thrown in at the charging door, but it is generally thrown in at the front, for it is more convenient to the material, and is also convenient for spreading it in the cupola. When the cupola is small the melter stands by the side of it and makes up the bottom by passing his arm in through the front opening; but when the cupola is large he CUPOLA MANAGEMENT. 83 goes inside, and his helper shovels the sand in as he wants it. The first sand thrown in is carefully packed around the edges with the hands to insure a tight joint. As the balance of the sand is thrown in, it is spread evenly over the bottom in layers from I to 2 inches thick, and each layer is evenly rammed or trampled down until the required thickness of bottom is obtained, which is from 3 to 6 inches, according to the rise of the cupola. The desired pitch or slope for throwing the iron to the front is then given, and the bottom butted evenly and smoothly all over. The melter next goes carefully around the edges with his hands and feels for any soft spots there may be near the lining, and slightly raises the edges of the bottom around the lining to throw the iron ofT and prevent it from work- ing its way down between the lining and sand bottom. The bottom is then carefully brushed and smoothed off, and in small cupolas a bucketful of thin clay wash is sometimes thrown in at the front and caught in the bucket as it runs out. This is called slushing the bottom, and is done to give a smooth, hard surface. The sand bottom does not always remain impervious to the molten metal, but is sometimes penetrated or cut up and de- stroyed by it, in which case a leakage of molten iron takes place from the bottom of the cupola that is difficult to stop. Leakage of this kind may be due to springing of the bottom doors when charging and the cracking or loosening of the sand bottom around the lining. This can be prevented by placing more props under the doors to support them. Sand that has been used over and over in a bottom until it has become worn out and filled with cinder is readily cut up and converted into a slag by the molten iron, and it is only a question of the time occupied in running off the heat whether the bottom gives way or stands. When the bottom sand gets into this condi- tion, it must be renewed by the addition of new sand, or the bottom covered with a layer of sand from the moulders' sand heaps. Molten iron will not lie upon a wet, hard substance, but will 84 THE CUPOLA FURNACE. explode or boil and cut up such material upon which it is placed. If the bottom sand is made too wet, or rammed too hard, or rammed unevenly, the iron will not lie upon it, but will boil and cut up the sand until it gets down to the doors, which it will melt, and run through. When a bottom cuts through, melters frequently attribute it to the bottom being too soft ; and we have seen them take a heavy pounder and ram a bottom as hard as a stone. In these cases, if the sand was worked very dry, or the bottom was well dried out before any molten iron came in contact with it, it did not cut up or leak; but if the sand was wet when the molten iron came down, boil- ing at once took place and the bottom soon cut through — and in such cases they generally cut through about every other day. In the sand bottom of a cupola we have the same ele- ments to contend with, so far as molten iron is concerned, as we have in a mould ; and the sand should be worked no wetter, rammed no harder, and rammed as evenly as the sand for a mould. The sand should not be worked wet for a bottom, under the impression that it is dried out before the iron comes down, for the ashes of the shavings, wood, coal or coke cover the bottom soon after the fire is started, and protect it from the heat to such an extent that it is only dried to a very limited degree before the iron comes down upon it. Water may be seen dripping from a very wet bottom long after the blast is on. Even if it were dried out, wet sand cracks when dried rapidly and should not be used. We shall not attempt to give any directions for stopping a leak after it occurs, for the time and place to stop a leak is when putting in the sand bottom ; and if all the remedies we have given for preventing leaks fail, then it is time to change the melter. The pitch or slope given to the bottom to cause the molten iron to flow to the tap hole from all parts of the bottom has a great deal to do with the temperature of the iron and nice working of a cupola. When the bottom is made too low and flat, molten iron lies in the bottom of the cupola and becomes dull. As the melted iron falls into this iron drop by drop, it is CUPOLA MANAGEMENT. 85 instantly chilled and the iron when drawn from the cupola is dull. This effect is more marked in a cupola melting very slowly, and a low bottom may be the cause of very dull iron when a sufftcient quantity of fuel is consumed to make very hot iron. A high pitch throws the iron from the tap hole with great force and spouting velocity, and it is almost impossible to run a continuous stream from a cupola with such a bottom. It is more dif^cult to keep the tap hole and spout in order, and the stream must be closely watched to prevent it shooting over the ladle and burning the men. Slag flows freely from the tap hole with the stream of iron when the bottom has a high pitch, even when there is very little slag in the cupola. But the flow of slag from the tap hole with the iron may be entirely stopped by changing the pitch of the bottom, no matter how great the quantity of slag in the cupola. The action of the iron at the spout is entirely changed by the pitch of the bottom. A hard iron may be made to run smooth from the spout, while a soft iron may be made to sparkle and fly, giving all the indications of a hard iron. The best expert on the quality of iron at the spout may be deceived in the iron by the pitch of the bottom, and it is only in the extremely hard and extremely soft irons they cannot be deceived. The bottom should never be made hollow in the center and high all around the outside with an outlet or trough to the spout. This concentrates the iron in the center in such a way that a few hundredweights place as great a pressure upon the front as a ton would do if the bottom were flat, and the front may therefore be forced out by a com- paratively small body of iron. The instant the tap hole is open the iron rushes out with great force, and it is almost impossible to stop it as long as there is any molten iron in the cupola. The bottom should be made flat and level from side to side with only a slight rise around the lining, which should not ex- tend out more than i or 2 inches from the lining. The pitch from back to front should not be more than ^ to ^ inch to the foot. This has been found to be a sufficient slope to throw all the iron to the front in an ordinary cupola. But in cupolas - |l ■ -- * Ijjjj|.. nn , 1 _ jj _ bPttt- ^^ >s I " Opposite each tuyere also is a sliding air-tight gate with peep hole, and in the beveled top is furnished a brass nipple to connect hose from the blast meter into the air chamber. " Our present tuyeres are of the latest and most approved patterns, so arranged that the blast is distributed over the MODERN CUPOLAS. I4I entire area of the combustion chamber, and are constructed in such form that the melted iron in its downward course cannot pas^ through them into the air chamber. If desired, these lower tuyeres can be made adjustable in height. "The Bottom Plate of each furnace is made in four (4) pieces, with joint over each leg, at which point it is reinforced by a steel plate. This arrangement permits of the necessary expansion and contraction without the possibility of cracking. " Each furnace is provided with a metal alarm and trap with fusible disc. "The furnace, as a whole, is simple in its construction. There is no complicated machinery or parts to get out of order, and consequently does not require any more attention or re- pairs than a common cupola. " In large shops, and where a large number of hands are em- ployed, the most important factor in melting iron is the rapidity with which it can be done. " The records of * the Colliau ' in this respect have never been excelled. " The Cupola can be operated by unskilled workmen, if in- structions are followed." THE NKWTON CUPOLA. The Newton Cupola, Fig. 30, while of modern design and fully up-to-date, reminds one of the days of the common, straight, plain cupola, when iron was supposed to be melted in a cupola and drawn from the tap-hole and not from the wind box. Mr. Newten. the designer of this cupola, evidently under- stood that melting is done inside of a cupola and not on the outside, for he has not devoted all his attention to the de- signing and construction of a wind box with elaborate air-tight hand-holes and openings for removing iron and slag from it, nor to the making of a cupola as big as a blast furnace or to resemble one by nonsensical outside attachments. But he has given to the outside a neat eupola-Iike appearance, while re- 142 THIC CUPOLA FURNACE. taining all the modern inside improvements in construction, arrangement of tuyeres, safety tuyere, slag-hole, etc. Fic. 30. THE NEWTEN CUPULA. MODERN CUPOLAS. I 43 The following is part of what the manufacturers have to say about it: "The Tuyere System, which is patented, is in accord with the best practical arid theoretical modern cupola practice. " The combined tuyere area is the important consideration, and the exact proportion which the areas of tuyeres, blast pipe and air chamber bear to the size of the furnace and the blower has been carefully adjusted to obtain the best melting speed and the most economical fuel results. ''The Main Tuyeres are of the expanded type, both inlet and outlet being of ample area to secure the transmission of sufficient air to the furnace. The increase in the area of the greatest portion of the tuyeres as they approach the fuel se- cures a blast of large volume and of moderate pressure nearest the iron, and the wide tuyeres afford nearly a continuous blast opening around the furnace walls. By these m.eans ample blast area is assured, even if a portion of the tuyere area is stopped by pieces of coke or other obstructions. " The lower tuyeres are adjustable vertically, through several inches, to suit either a deep or a shallow bed of fuel. This adapts the furnace to either coke or coal, or to any change in the inside diameter of the furnace, to suit different classes of work. " One tuyere has a low spout connected with a soft metal ])lug; this is burned out and gives warning if the molten iron should rise too high. "The upper tuyeres are fitted with dampers enabling them to be closed if desired ; the main tuyeres having ample area for the required capacity. "Special attention has been given to methods of getting the blast to the fuel in the most direct and efficient manner. "The entire body of the air chamber — bottom, top and sides — is made of plate steel, flanged, riveted and caulked, insuring an air-tight construction. "The blast enters the air chamber through a single inlet, which branches to right and left, giving a tangential motion to the blast in both directions. 144 THE CUPOLA FURNACE. "The bottom of the air chamber is raised several inches above the bottom plate to afford free inspection of the bottom of the shell at all times, it being at this point that cupola shells most frequently fail through rust. " The bottom plate is very thick, and is heavily ribbed ; a flange extending around the entire shell. "Bottom doors are of the hinged- drop type, with perforated plate and four heavy ribs on each door. On large cupolas there is provision for the attachment of levers for lifting doors into place. " A slag opening is located below the lower tuyeres, its height being adjustable to suit conditions. It is fitted with a suitable slag spout. By using the slag hole, the cupola can be kept from clogging, and continuous melting for a long period will result. "The charging door is extra large. The frame has a heavy iron slide at its base, protecting the lining. The charging doors may be either of the plate type for brick or mud lining, or of the wire screen type, the former being used unless otherwise or- dered. Two charging door openings or frames are provided on all cupolas left larger than ']2 inches. " Our No. 30 Cupola is often sold as a test cupola, for work at technical schools, or in large plants for testing quality of iron. It can be mounted either on trunnions or on columns in the regular way. " In this cupola but two large tuyeres are used, and the air is carried direct to the tuyeres from a branched blast pipe, the standard air chamber being omitted." PAXSON COLLIAU CUPOLA. In Figs. 31, 32 are seen external and sectional views of the Paxson Colliau cupola, illustrating the two zones of melting as designed by Mr. Colliau, but changed in some important details in construction in this cupola, to bring it fully up to date as a latest improved cupola. The lower tuyeres are rectangular and flared, and the upper ones are oval. They are staggered MODERN CUPOLAS. 1 45 SO that there is very little dead space, the blast reaching every part where it is wanted, being distributed evenly. Therefore, the lining is not affected by the action of the blast to the ex- tent that would be expected where upper and lower tuyeres are used and two zones of melting are at work. There are six lower and six upper tuyeres which tend downward. This makes better combustion and prevents molten iron from enter- ing the wind chamber through the tuyeres. Through the greater portion of the heat there is very little or no flame shown at charging doors, showing that the upper tuyeres pro- vide sufficient oxygen where it is wanted below the stock in the cupola where the heat is most severe. The tuyeres are rendered readily adjustable by a novel and simple arrangement. The tuyere boxes are made double or in two sections when desired, and when it is deemed advisable to lower the tuyeres, bricks are removed from the lower section and placed in the upper one. In this way the tuyeres may be raised or lowered in a few minutes without disturbing the lining outside of the tuyeres. A low safety tuyere and trap with soft metal plug is pro- vided, which discharges any overflow through the bottom plate. Therefore should the iron rise unexpectedly there is no possibility of it getting into the wind chamber through the tuyeres and injuring the chamber, as the cornucopia-shaped trap shown in Fig. 32 receives it and permits it to flow at once out of the chamber. The upper tuyeres can be opened or closed by the turn of a crank that is arranged for opening and closing them, and the cupola made a single tuyere cupola for small heats or a double tuyere one for a large one when fast melting is required. A slag-hole spout is placed in the back so the slag can be drawn off at will. It is this fact that makes this cupola a con- tinuous melter. The cupola is made of any size wanted, from 12-inch inside diameter up to any capacity desired, and is constructed in three sections or distinct parts, viz.: No. i, bottom plate and sup- 10 146 THE CUPOLA FURNACE. ports; No. 2, portion of base 3 to 5 feet high, according to size of cupola, with air chamber, upper and lower tuyeres, tap trough, slag spout and blast gauge; No. 3, casing, charging Fig. 31. Z777OT7ZP3 Fig. 32. rlflf""^^ Fllh », -- --.■..■.■.: . ::* L _.,. __ _p! j 1 I- - \ - - i. - ~ P- ^ — ^ ^'^ PAXSON COLLIAU CUPOLA.. -.-nacfi ■> II \ __ 1 ^ ! 1 ■ - 1 \- ' --- — :rr ' - - - — J _ t ..^ -^^--^ ----- --- it ^- - - 1 """mi — — — p y»-J" '"1 H /y V // ^J] i \ l.^ \ V j n n _ , 1— j ... 1 1 r- ^ .^-i; =t j p iiPt 1 ' i 1 1 1 J 1 "ij _C V- i zi _, \ r y////Ji& . zLJzi_4| m SECTION OF PAXSON COLLIAU Cl'POLA. MODERN CUPOLAS. 147 doors and stack. The cupola may be ordered complete or in parts, thus enabling parties desiring to make only a small outlay to obtain a fully up-to-date cupola by ordering only the essential parts of it and constructing the remainder from material at hand. The legs or supports are made any length desired from 2 to 7 feet, so that the cupola may be placed at a height suitable for ladles used in pouring or that a car may be placed under cupola for receiving the dump and removing it to the yard or tumbling barrels, where it may be quickly cooled and milled. Fig. The drop doors, when desired, are fitted with counter-balance weights to facilitate raising them into place. In Fig. 33 is seen the indestructible wire screen charging door with which this cupola is fitted. It requires no lining and does not warp or crack. As before stated in this work, a charging door has nothing to do with a cupola melting, and is only of use to give draught for lighting up and prevent sparks or pieces of fuel being thrown upon the scaffold toward the latter end of a heat, and this door answers every purpose. It 148 THE CUPOLA FURNACE. is hung on the outside of the cupola and does not come in con- tact with the heat to the same extent as the lined or iron door, is lighter and easy to swing and lasts longer than either of the others. This door, although called indestructible, does not last forever, and its frame is constructed in such a way that the wire screen when destroyed by slow corrosion may be re- moved and replaced with a new one in a very short time. Small cupolas of this construction are made especially for the use of technical schools and colleges, and also for use in large foundries for testing brands of pig iron, and in interior towns for melting small quantities of iron. THE WHITING CUPOLA. In Fig. 34 is seen the Whiting patented cupola, designed by Mr. Whiting, a practical foundryman, of which the following description is given by him: The universal satisfaction given by the Whiting cupola is largely due to the patented arrangement and construction of the tuyere system, which^is so designed as to distribute the blast most efficiently, carrying it to those portions of the cupola where it will do the most good, under a reduced pressure, and through an increased area. There are two rows of tuyeres. The lower ones are arranged to form an annular air inlet, distributing the blast continuously around the entire circumference of the cupola. This system of tuyeres is also arranged to be adjusted ver- tically. This provides for adjustment to the class of work, kind of fuel, and changes in the inside diameter of the cupola. These tuyeres are flaring in shape and admit the blast through a small area which is expanded into a large horizontal opening on the inside of the cupola, thus permitting the air to reach the fuel through an area nearly double that through which it enters the tuyeres — admitting the same volume of blast, but softening its force. There is an upper row of tuyeres of similar construction to supply sufficient air to utilize to the fullest extent the escaping MODERN CUPOLAS. 149 carbon gas. These tuyeres are of great service in melting and in large heats — for small heats they may be closed by means of our improved tuyere dampers. Fig. 34 represents the latest type of the Whiting patent cupola. A half-vertical section is represented, showing the arrangement of the improved tuyeres and the method of ad- FiG. 34. ELEVATION. -J^. 'Wl m- SECTION SECTION OF WHITING CUPOLA. justing them vertically. These tuyeres are arranged on slides and can be placed at various heights, as shown by dotted lines. It sometimes happens that the operator finds the cupola too large for his needs. When this is the case, a thicker lining can be used and the tuyeres adjusted accordingly, and for small 150 THE CUPOLA FURNACE. heats the proper ratio of coke to iron can be maintained ; other- wise a large cupola running small heats will decrease this ratio materiall)', adding considerably to the cost of castings. A change can be made from coke to coal fuel and the bed made of suitable depth, by simply adjusting these tuyeres. No other cupola has this device. It practically gives the operator two cupolas in one. This figure also shows the safety alarm attachment, side plates, improved blast meter and upper tuyere dampers, etc. Every cupola is provided with the foregoing improvements,^ together with foundation plate, bottom plate and doors, columns (three to five feet long), slag and tapping spouts and frames, peep holes with fittings, patent tuyeres and charging doors and frames. All fitted ready to erect. THE EJE CUPOLA. The illustration, Fig. 35, shows the general external appear- ance of the standard EJE Cupola, the above cut showing Body Section X. The blast pipe entering the wind box on a tangent has been found to be the most successful method for the en- trance of the blast, and the heavy construction of castings forming hearth plate, drop doors and legs will be noted. Tuyere System. — The EJE Cupola is furnished with two rows of tuyeres as shown in the illustration, the upper row being so spaced that they come exactly halfway between the tuyeres on the lower row, distributing the air evenly throughout the bed of the cupola. The tuyeres are flaring in shape; the air enters through a small opening in the shell, same expanding into a larger one in the inner circle of the cupola, finally reaching the fuel through an opening of almost double the area of the one through which it enters the tuyeres, thereby reducing the air pressure while admitting the same volume, thus softening the blast. Note the space between the openings of the lower tuyeres on inside of cupola is reduced to the minimum, allowing air to enter the cupola from almost every point on the inner cir- cumference. MODERN CUPOLAS. 151 The upper tuyeres are of similar construction to the lower and supply sufficient air to consume all escaping fuel gas; they are of great service during long heats or, if very quick melting is desired, they may be opened or closed independently of each other by a small damper operated from outside of the cupola. POINTS OF SPECIAL MERIT IN THE EJE CUPOLA. Two or more Safety Tuyeres are provided with each cupola, Fig. 35. E. J. E. CUPOLA-BODY SECTION. which give automatic warning when the operator allows iron to get too high in the cupola. A cast-iron box flared at top directly under each Safety Tuyere positively prevents any overflow of metal getting into the Wind Box. 152 THE CUPOLA FURNACE. Tapping Spout cast iron, of improved design, of extra width and depth. Slag Spout is of heavy cast iron, of sufficient length to allow slag to run into small wagons, if so desired. Cleaniug Doors are of cast iron, very readily removed, allow- ing furnace tender to easily clean out interior of air chamber when necessary. Two cleaning doors on sizes up to and in- cluding No. 66, and four on all sizes above. Peep Hole Frames and hinged covers machined air-tight are placed opposite all tuyeres, upper and lower, covers are fitted with mica peep holes and can be opened when necessary to get into tuyeres. A Mercury Blast Gauge of improved design is furnished with each cupola; the gauge is enclosed in an iron box with hinged cover, keeping the glass clean and preventing breakage. Tuyere System — The tuyeres are of such a shape that they will readily hold themselves in the lining and will distribute the air equally throughout the melting zone. The upper tuyeres can be opened or closed by means of a small damper. Linhig Supports of cast iron are bolted to the inside of the stack and are of sufficient strength to support the lining; one shelf is placed above the melting zone, one above the charging doors and others in the stack, the number, of course, depend- ing upon the height of stack desired. In Fig. 36 may be seen the inside construction and general design of the Calumet Cupola. As an iron melter this cupola, being the latest design, pos- sesses all modern features of economy of fuel and lining, rapid and continuous melting, resulting in a hot fluid iron of uniform grade throughout the heat, and a wide range of work. The design is the simplest and strongest yet produced in a cupola, and the construction is of the highest grade both as to material and workmanship. While all essential features of previous designs are retained, new features of importance are to be found exclusively on this cupola. MODERN CUPOLAS. 153 Air Chambers. — A conspicuous feature of the design of a Calumet Cupola is the placing of the air chamber inside the Fig. 36. CALUMET CUPOLA. furnace shell. This construction increases the thickness of the lining at the melting zone just above the tuyeres, thus avoiding 154 'I'HE CUPOLA FURNACE. any burning of the shell due to destruction of the lining at this point. By thus placing the shell on the outside it is easily in- spected at the bottom where inaccessible cupola shells usually fail because of rust. The inside plate of the air chamber being removable may be replaced if burned out. The conical shape of the furnace shell results in an enlarged base, giving great stiffness and stability to the cupola. These features of the de- sign will be readily appreciated, as they greatly increase the strength and life of the cupola. Blast Inlets, one on each side, to insure equal distribution of blast around cupola, may be attached as location of cupola re- quires, and may be either radial or tangential. Tuyeres are of the modern rectangular, expanded type, prop- erly proportioned to the cupola area and the outlet of any standard blower, and provide a nearly continuous blast open- ing around the furnace walls. The upper tuyeres provide an air supply to complete the combustion, and are equipped with dampers for closing them if desired. A safety tuyere is pro- vided near the slag spout, which prevents the molten iron rising and flowing through the lower tuyeres. Shell and Stack are of steel plate riveted in sections with downward joints, convenient for erection. Angle lining sup- ports are riveted to the shell at intervals, and the lining is of standard fire brick. Furnace Supports. — The cupola rests upon a heavy cast-iron flanged base ring, to which the furnace shell is bolted on the outside, and the removable air chamber plate on the inside. The cast ring rests upon ribbed columns which stand upon cast base plates, held together with steel rods. The base plates amply distribute the weight. The columns are curved to allow the drop doors to swing back free of the dump. Doors and Peep Holes — The drop doors are hinged to the base ring by heavy lugs and pins. They are substantially ribbed, are perforated, and provided with eyes for inserting a lifting rod. The charging door mgy be of the perforated plate or screen MODERN CUPOLAS. I 55 type, or it may be of cast-iron arranged for brick lining, the latter being the standard construction. Clean-out doors are provided in the air chamber, being machine fitted in an air-tight manner. Peep holes are provided opposite each tuyere, being of mica mounted in removable frames, which are machine fitted to be air-tight. Spouts — The spouts enter the furnace through cast-iron frames in the air chamber, bolted to the shell. The slag spout is adjustable to suit the height of the tuyeres. The tap spout is located opposite the slag spout, and may be of any length required. CHAPTER Vll. LARGE CUPOLAS. THE HOMESTEAD LARGE CUPOLAS. Probably the largest cupolas in this country are those of the Carnegie Steel Works, Homestead, Pa. These cupolas, four in number, were constructed for the purpose of melting pig iron for converting into steel by the Bessemer process, and are of the following dimensions : Diameter of cupola casing, 12 feet. Diameter of cupola stack, 12 feet. Height of charging opening above iron bottom, 30 feet. Height of stack, 15 feet. Stack supported on cast-iron columns 3 feet long, resting on top of cupola casing, with opening all around for charging stock from blast furnace barrows. Thickness of lining to a short distance above tuyeres, 27 inches. Thickness of lining from this point to top of cupola, 12 inches. Diameter of cupola at tuyeres, 7^ feet. Diameter of cupola above tuyeres, 10 feet. Diameter of stack, 12 feet. So little heat escaped from top of cupola it was not found mecessary to line the stack. Number of tuyeres, 16. Size of tuyeres, 4x6 inches. Height of tuyeres above iron bottom, 6 feet. The tuyeres were placed at so great a height for the purpose of holding molten iron in the cupola for a charge of a Bessemer converter. (156) LARGE CUPOLAS. I 57 These cupolas were designed to be kept in blast as long as the lining would last, and for this reason the casing from the bottom plate to above the melting zone was constructed of cast iron flanged sections, bolted together on the outside, so that in case the casing burned through a section could be removed and replaced by a new one. But this method was not found to be practical and the cupolas were only kept in blast from i a. m. Monday morning until Saturday noon before dumping. These cupolas which have probably been abondoned since the construction of a bridge across the Monongahela River for conveying molten iron direct from the blast furnace to the con- verters, were never a success so far as making hot iron or rapid melting was concerned for they seldom produced hot fluid iron and the melting capacity of each one did not exceed 12 tons per hour, while the melting area at the melting zone was suf- ficient to have melted 30 tons per hour. This was no doubt due to the diameter at the tuyeres being too great for forcing blast to the center of the stock from side tuyeres, and the cupola not melting properly in the center. The Jumbo cupola described elsewhere in this work which is only 54 inches diameter at the tuyeres melted 15 tons per hour of hot fluid iron for stove plates, soil pipes, etc. Had these cupolas been contracted at the tuyeres, to some- where near this diameter, and the lining shaped upon a plan similar to that of the construction of the Jumbo Cupola, their melting capacity per hour would no doubt have been double, and a great deal less fuel required in melting. In all cases, the lining of very large cupolas should be shaped similar to that of a blast furnace, for it is only by getting the blast to the center of the stock in these furnaces that they are made to produce the enormous quantities of iron they are capable of producing. This is done by contracting or boshing the furnace near the bottom, where the blast enters the stock, THE McSHANE LARGE CUPOLA. Another very large cupola that attracted considerable atten- 158 THE CUPOLA FURNACE. tion at the time of its construction was one at the McShane foundry plant, Baltimore, Md. This cupola was 98 inches in diameter inside the lining, and was designed to melt iron for soil pipe, plumbers' fittings, etc., such castings requiring very- fluid hot iron to run them. It, however, was not a success as regards making iron hot or rapid melting with the above diameter. This was attributed to the force or volume of blast not being sufificient for the size of the cupola. But a larger blower when placed in operation produced but little better results. Failure was then attributed to the tuyeres, but numerous changes in their size and design gave no better results, and it was not until the diameter of the cupola was greatly reduced by increased thickness of lining that a satisfactory iron was melted, with a melting capacity per hour greatly reduced from that originally designed or calculated. This cupola, which is still in use, was declared a Jonah soon after its construction. It melts very unevenly, producing hot, even iron for a while and then dull, uneven iron. When called upon a few years ago to locate the cause of this uneven melting, I found that the twenty inches or more of lin- ing put in to reduce the diameter had become shaky, and a great deal of the blast escaped through the lining instead of passing through the stock, and heat escaping through the melting zone was not all utilized in heating and preparing the iron for melt- ing before descending into the melting zone. This is a diffi- culty that may be remedied by using a good plastic, adhesive material in laying up the lining and by carefully daubing any openings that may occur in it all the way up to the charging door. But these are precautions seldom taken by cupola men unless their attention is frequently called to them, and it is far better and more economical to have a cupola constructed of the de- sired size with the proper thickness of lining than to reduce the diameter by extra thickness of lining. Another trouble with this cupola was the colored help employed to man it. These LARGE CUPOLAS. I 59 men frequently permitted the stock to get too low in the cupola for good melting, and when it became very hot at the charging door, stood back, and blast had occasionally to be taken ofif until the cupola was filled up. This was very bad cupola practice. THE THOS. D. WEST LARGE CUPOLA. To overcome the difificulty in cupolas of large diameter, not melting well at the center of the stock, Thos. D. West con- structed at the plant of the Thos, D. West Foundry Co., Sharpsville. Pa., a cupola, having a 92-inch shell, lined with 8-inch brick, giving a diameter of 76-inch inside the lining. In this cupola, in addition to the usual number of side tuyeres placed in cupolas of this size, he placed a center blast tuyere, the top of which stood three feet above the iron bottom. It was constructed of heavy cast-iron pipe upon which prickers were cast for holding daubing. It extended up from the floor and was made permanent or stationary in the cupola, the bottom doors being cut out to fit up around it. On the top of this pipe was placed a hood or rounded cover fifteen inches in diameter, from under which the blast entered the stock all around the hood. The pipe and hood were daubed for each heat with the same daubing material used for repairing the cupola lining, and the sand bottom was made up around the pipe. This cupola melted, when in blast and properly charged, from eighteen to twenty tons per hour, and was pronounced a suc- cess by Mr. West. However, there was at times more or less trouble with the center blast, due to the daubing being knocked or rubbed off the hood by the stock when thrown in and iron getting into the tuyere, and also from the tuyere pipe being crowded to one side by an uneven settling of the stock and causing a leak through the sand bottom. The foreman at the plant, when visited by the writer a few weeks ago was of the opinion that these difficulties could have been overcome by covering the hood with fire brick, in place of daubing, and constructing the tuyere pipe in a more substantial manner. This firm is engaged in the casting of ingot moulds l60 THE CUPOLA FURNACE. by the direct process, and this cupola is designed only for melting iron when the blast furnace, from which they obtained their molten supply was not making iron suitable for their cast- ings. But since its construction, the firm have arranged to ab- tain molten iron from any one of three blast furnaces that ma}'' be producing suitable material for their castings, and the cupola has not been in blast for the last three years, and is not likely to be put in blast again, so that these points may never be determined. However, the principle is no doubt correct and, if the difficulties that have been met with in the use of a center blast tuyere can be overcome by making this tuyere stationary and more substantial, large cupolas can be made to melt as well at the center as smaller ones by the use of this, tuyere in addition to outside tuyeres. Another plan of making large cupolas melt at the center, is to contract them at the tuyeres to a diameter of 55 to 60 inches. This diameter has been shown by numerous tests to be about the proper one at the tuyeres for fast and economical melting. Straight cupolas of larger diameters than this, have been made to do fast melting by the use of large positive blast blowers; but this has been done with considerable uncertainty as to a hot even temperature of iron throughout the heat, and at a greater expense for power, than actually necessary for the amount of iron melted per hour or during a heat. A diameter of 55 to 60 in. at the tuyeres may readily be obtained in cupolas of larger size without danger of bridging or hanging up, by boshing the cupola, as shown in Figs. 68, 'j'j and 79,. from the bottom plate to a short distance above the tuyeres, or contracting it at the tuyeres only as shown in Figs. 65 and 66y or by placing the Zippier or Knoeppell tuyeres in the cupola. Each of these plans has given hot even iron with less fuel in large cupolas than could be obtained in cupolas of over 60 inches in diameter at the tuyeres. The boshing from the bot- tom plate up, is by far the best plan for cupolas from which iron is drawn as fast as melted, as considerable less coke is re- quired for a bed. The molten iron is more concentrated in its. LARGE CUPOLLS. l6l descent and reaches the tap hole more rapidly and hotter iron may be obtained. But when it is necessary to hold molten iron in a cupola while waiting for a large ladle to be returned from the casting floor, or iron is held upon the erroneous theory that when molten it may be kept hotter in a cupola than in a ladle, the tuyeres have to be placed higher up, and this saving in coke in the bed is not cfTected ; for this style of melting, the projecting tuyere will probably give the best results. Each of these shaped linings and arrangement of tuyeres has given excellent results in melting in large cupolas, but these results can only be obtained by kee[Mng the lining in the shape outlined in the illustrations. To maintain this shape, a blue print of the design adopted should be framed and hung up near the cupola for the guidance of the mclter and foreman, in case the cupola does not coniinue to give the melting results obtained in the first or trial heats. The success of all fancy shaped linings depends upon maintaining the shapes that give the best results in melting. ADVANTAGES AND DISADVANTAGES OF LARGE CUPOLAS. The advantages claimed for a large cupola capable of melt- ing all the iron lequired for a plant in the shortest possible time are, that it admits of iron, fuel, and all cupola material be- ing concentrated in one point, in the yard or stock room. One blower is all that is required. One elevator or other device for getting up iron or fuel is sufficient. Less lining and daubing material is required. Only one melter is required and fewer men are necessary to man one cupola than two. All these claims are correct up to a certain point, but beyond this point they almost entirely disappear. For a large blower frequently costs more than two smaller ones, and more power is required to run it than two small ones. With onl)' one ele- vator or other device provided for getting up stock, men fre- quently have to wait their turns to use it, and in many cases II 1 62 THE CUPOLA FURNACE. for this reason more men are required for getting up stock for one cupola than for two smaller ones, melting the same num- ber of tons. In cupolas melting from eighteen to twenty tons per hour, the stock settles so rapidly that extra men are required in charging, to keep the cupola filled to the charging door, and if it gets awa}' from them it becomes so hot that blast has to be taken oiT until filled up. Fuel and iron have to be thrown in so rapidly that the fuel is often not evenly distributed or the different brands of iron are not properly mixed in charging, the result being an iron of uneven temperature at the spout, and also an uneven grade of iron from the mixture. For heavy work, or water pipe, car wheels, etc., this may not be an objectionable feature, for the iron is handled in large ladles and the temperature may be equalized in the ladle and the iron mixed, and an even grade obtained from the mixture. But for light work such iron is unfit for objects to be cast, and it is only when it is handled in large ladles by crane or tracks that it can be used and an even grade of it in the castings obtained. Another objection to the very large cupola for light work is the long distance the molten iron has to be carried when this is done by crane or track, the iron frequently becoming too dull to run the work, and many castings are lost. When car- ried by hand the iron not only becomes dull, but more time is required for casting and hence less time for molding. It will thus readily be seen that while there are advantages in concen- trating all the melting at one point in one cupola, there are also many important disadvantages. As a rule it is more profitable to install two or more cupolas than one large one, and these should be placed at the most convenient point for distributing in the shortest possible length of time molten iron to the work to be cast. For more time can be taken in bringing cold iron to a cupola than in getting molten iron away from it. What is meant by a large cupola is one capable of melting 1 8 to 20 or more tons per hour. When this amount of iron is required it LARGE CUPOLAS. 1 63 will generally be found more profitable to install two cupolas to melt it than one, especially for light work, and to place them at such a distance apart as will give the shortest possible carry for the molten iron. By this arrangement hotter and more fluid iron can be delivered at the moulds with a minimum amount of labor and time, and even for the heavier class of work this will be found to be of advantage in making sound, clean castings. Another matter that must be considered before installing a large cupola is the method of handling the molten iron with large ladles. Almost any amount can be handled per hour if sufificient ladles and means of handling them are pro- vided, but with small hand and bull ladles the amount of iron that can be taken from a cupola spout running a continuous stream is only about 8 ton per hour. Even this amount re- quires very rapid handling of ladles, and if the stream once gets away from the men and it becomes necessary to stop in to re- move iron from the floor and get control of the stream, even faster handling is necessary to get rid of the iron accumulated in the cupola during the stop-in, and the danger of handling the iron is increased. For this reason two tap holes should always be placed in a cupola melting over 8 tons per hour when the iron is all han- dled in small ladles. CHAPTER VIII. SMALL CUPOLAS. In the early days of foundry practice in this country only small cupolas were used. A fifteen to tv\enty inch inside diameter cupola was considered to be the proper size for a jobbing foundry, and a diameter of forty inches was the limit for large cupolas. In foundries equipped for heavy castings three cupolas of dififerent sizes were installed and arranged to be put in blast separately, or all placed in blast at the same time. When a piece was to be cast requiring more iron than could be melted in the largest cupola in a given time, one or more additional cupolas were put in blast at the same time, and in this way the founder was able to cast the largest piece required in those days. This arrangement also saved consider- able fuel, for the founder could put in blast a cupola to suit the size of his heat and adapt himself to good or bad times, a thing that cannot be done at the present time in cupola practice in many foundries. With the increase in the size and capacity of foundries the size of cupolas were also increased until we now have them up to ten feet inside diameter, and one would think from reading cupola literature in scientific papers and monthly periodicals, most all of which matter pertains to practice in large cupolas, that the small cupola had gone out of use. This is by no means the case, for the small cupola has kept pace with the large one in improvement of design and construction, and is still extensively used, not only in the small foundries where its capacity fills the requirement of the foundry for work to be cast, but also in large foundries in many of which its value as a money maker or saver has been overlooked by the manage- (164)- SMALL CUPOLAS. 1 65 ment. It is well known among practical founders that neither fracture indication nor chemical analysis accurately indicates the resultant quality of an iron that may be obtained from a new or untried brand when added to or used to replace another brand of iron in the regular foundry mixtures. To determine- this accuratcl}- the iron must be actually melted and cast, and may result in the loss of an entire heat or part of a heat from the iron being too hard, soft or weak for the work to be cast. Such loss may be reduced to a minimum by first testing a new brand or mixture of iron in a small cupola capable of melting from a two hundred weight to a ton, and casting all or part of it into the regular line of castings and the balance into unim- portant castings. It is absolutely necessary that in all tests of this kind a siifificient quantity should be melted to insure a hot fluid iron to run the work and the mixing of the different brands in the mixture, which cannot be done with only a few pounds of each brand. The small cupola is of value in making a mixture for a few hard or strong castings such as gearwheels or chilled castings when the regular heat is all soft iron, or a few soft castings when tiie heat is hard iron. This is done by melting the hard or strong iron in the small cupola at the same time the regular heat is being melted, and mixing the two molten irons in a ladle. In this way after a little practice an iron of any degree of hardness may be obtained without risk of hard iron getting into soft work, as would be the case if a special charge of hard iron were made in the regular heat. In the same way a few softer castings may be cast when the regular heat is hard iron, by melting a high silicon iron in the small cupola and mixing it with the hard iron. This practice is now regularly followed in many large foun- dries making only a limited number of castings for which a hard, close, strong iron is required. A semi-steel mixture may also be made in this way more accurately than when the mix- ture of iron and steel is melted together in the cupola. The small cupola is also of value in a large stove foundry for cast- 1 66 THE CUPOLA FURNACE. ing patterns or getting out a few repairs when the foundry is shut down. And in the large machine or jobbing foundry for turning out a few castings when shut down or getting out a rush order for a breakdown, furnishing hot iron for feeding up a .large casting after the heat has been melted and bottom dropped, etc. SWIVEL CUPOLAS. Now in Fig. 37 is shown a small cupola known as the Swivel Cupola, from being hung upon bearings in the center upon which it may be turned upside down to dump after a heat, or laid upon its side in chipping out and in repairing the lining. This style of small cupola is an old one, and was described in the writer's first work on cupola practice published in 1877. It was first made with a stationary bottom, and designed to be dumped after a heat by turning it upside down, but this was found to be impracticable, for the bottom became heavy and hot at the end of a heat and difficult to turn, and when turned only a limited amount of the melting refuse dropped out. The dropped bottom was therefore added and the cupola laid on its side for chipping out and repairing the lining. This de- sign is best suited for cupolas of from twelve to fourteen inches diameter, for if made of larger diameter it is too heavy to turn. The top of the cupola must have room for turning under the stack plate, and does not connect with the stack by several inches. It should therefore be of sufficient length to hold the required amount of stock, as none of it can be placed in the stack in charging. Cupolas of this design melt well when properly constructed and managed, and are nfiOre convenient for chipping out and repairing the lining than any other design of very small cupolas. This cupola calls to mind a small one in use at the foundry of Charles Spangler, of Allentown, Pa., which was probably originally designed for a swivel cupola. The stack is supported upon iron columns, as shown in Fig. 37, but the smaller section is mounted upon four small wheels placed at the bottom upon iron rails upon which this section is SMALL CUPOLAS. Fig. 37. 167 I 68 THE CUPOLA FURNACE. drawn from under the stack for chipping out and daubing. This section is only about four feet long, and can readily be chipped out with a bar from the top and the lining repaired at the melting zone without going into the cupola. When the lining has been repaired it is put back in place and the joint between the cupola and stack is luted. This luting makes the connection between the stack and cupola and admits of the charging door being placed at any desired height, it being for this reason a more desirable design for the larger-sized small cupola than the swivel cupola. This cupola has been in con- stant use for many years, and supplies from two to six moulders with iron for light castings. A PORTABLE SMALL CUPOLA. The illustration Fig. 38 recently appeared in" The Foundry" together with the following description by Mr. Dan Calvin, All foundries have to produce castings in a hurry at times, and sometimes it is inconvenient to wait for iron from the regu- lar cupola or to fire up one of the large cupolas for a small quantity of metal. A small portable cupola such as that shown in the accompanying illustration, will be found very serviceable indeed for such occasions as this. The cupola shown is in use in Paducah, Ky. It has no stack and is set against one wall of the foundry. Air for the blast comes from the blacksmith shop, which is about 20 feet away, the air being conducted through a pi{)e underground and brought up behind the cupola as shown. Connection is made with the cupola by means of a gland, as shown in the illustration. The diameter of the shell is 18 inches and the height of the shell 5 feet. All of the cast- ings for the cupola were made in open sand, and the construc- tion was such that very little patternmaking was required. The bussel pipe is a ring of square cross section, about 5 inches on a side. The tuyeres are made from i}4 inch pipe. The cupola is mounted upon a frame upon wheels, as shown, so that it can be moved away from the wall for cleaning and repairs. The A-shaped frame which supports the trunnion is SMALL CUFOLAS. 169 5 feet high, tlie center of the trunnion about 3 feet 6 inches irom the floor. When in use the cupola is Hned with molding sand, % of an inch thick. A casting weighing 300 pounds can be made with this cupola, and a heat of 700 pounds of metal can be taken from it. The charges for such a heat are as follows: Three Fir. 38. riddlesfull of coke for the bed and 300 pounds of iron. This is followed by two charges composed of one riddle full of coke and 150 pounds of iron each, and one charge of one riddleful of coke and 100 pounds of iron. The cupola can be gotten ready and hot iron available in from an hour to an hour and a half at any time. When large 170 THE CUPOLA FURNACE. brass castings are required, the cupola is simply relined and from 300 to 400 pounds of brass melted in it without any difficulty.* A CHEAP SMALL MOVABLE CUPOLA. In many foundries the cupola arrangement is such that the addition of a small cupola near the scaffold and blast pipe would be in the way and a movable cupola is therefore desired. A small neat and practical cheap construction answering this purpose has been in use for many years in a foundry at Tren- ton, N. J. This cupola is constructed in two sections each of which is about four feet long. To the lower section are at- tached the bottom plate, cupola legs or supports and drop door. Each section is provided with lugs or handles near the top for lifting. When wanted for melting, the lower section is lifted with the crane and placed in position alongside of the cupola scaffold, and the other section is placed on top of it, and the joint luted with clay. Connection is made with the cupola blast pipe and the cupola is ready for use. The foundry roof being high, no stack is required and the cupola is charged at the top from the regular cupola scaffold, making this prob- ably the cheapest small movable cupola that can be designed. After a heat has been melted, if the cupola is no longer wanted for immediate use, the sections may be lifted with the crane and placed in a corner out of the way until again wanted. This cupola has been put in blast daily for months to melt iron for two moidders casting wagon boxes, and cheaper melting was done than could have been effected in the regular foundry cupolas for this number of moulders on light work. Many other cheap small cupolas that the writer has seen in operation in foundries might be described such as an old steam boiler, or * This cupola when lined as described would have a diameter of sixteen and a half inches and the tuyere area is entirely too small for a cupola of this size. The lining of three fourths of an inch of moulding sand is too light for a l')ng heat and the lining material is loo friable for safety, as it may readily be knocked or rubbed off in charging ard setting of the stuck. At least a two inch firebrick lining should be placed m all small cupolas, and if long heats are to be melted a four-inch lining will prove more satisfactory. SMALL CUPOLAS, 171 smoke stack set on end and lined, or two or three wooden barrels placed one on top of the other and lined. In fact, small cupolas have been made by small foundries in their efforts to get into business, from almost every old cast-ofF material hav- ing the shape of a cupola that would hold a lining in place, and iron has been successfully melted in them for years, or until the founder could afford to construct or purchase a better cupola. The small cupola is more difficult to manage than a large one as the tendency to bridge or bung up is greater, but a twelve-inch cupola may be kept in blast for ten hours or more and good melting done if properly charged and fluxed. In England cupolas of this diameter have been kept in blast for a week without repairs to lining by knocking out the front after a heat, raking out the slag and refuse, putting in a new front and bed of coke to be ready for charging iron the next morn- ing. In this way the melter was able to put the blast on at seven in the morning and melt all day. THE KEEP SECTIONAL CUPOLA. In Fig. 39 is shown the Keep Sectional Cupola designed by Mr. W. J. Keep, the well-known authority on foundry practice, and inventor of mechanical analysis. It is made in sections, 18 inches deep and about 27 inches outside diameter (Fig. 40). These are lined with ordinary stock brick laid flatwise. The complete lining is about three inches thick, making the inside diameter 21 to 22 inches. A ring of angle iron is riveted to both ends of each section for stiffness, to hold the brick in place and to make a joint between sections. The lower section contains a wind box and tuyeres. This section is set on a solid truck on wheels, so that the cupola can be rolled to any point required. The wheels can be either flanged for a track, or flat tread wheels. The sections can be handled either by a trolley, placed a little to one side of the stack, and with an ordinary chain hoist, or by a light bracket or jib crane. The stack may be suspended by rods or otherwise from the foundry roof. It is 27 inches in diameter, and flares at the \J2 THE CUPOLA FURNACE. lower end, which is about eight feet from the floor, and is just high enough for the cupola to roll under it. One side of the flaring portion is cut away for a charging door. The three inch opening between the top of the cupola and the edge of the stack creates a strong draft and keeps the air fresh around the cupola. To take off a heat the bed-plate is rolled under the trolley track, and the lower section put in place. The sand bottom is put in, 2^ inches thick at the front and 3 J^ inches at the back. The spout is lined, the breast put in, and a slag hole made at the rear. Shavings and kindling are laid in this section and the other three sections put in place, daubing the joints on the inside. ¥\c,. T,(). Fig, 40. The cupola is then rolled under the stack, and the pipe be- tween the blower and the wind box connected. A charging platform should be made of boxes or flasks and coke charged. The fire is usually lighted two hours before charging iron. When the coke is well lighted iron and coke should be charged in accordance with directions furnished by the manufacturers. The cupola holds three charges, which can be placed in 15 to 20 minutes. The pig iron is to be broken into pieces about 10 inches long, and the scrap as small, and charged evenly. The blast is put on 15 minute; before iron. SMALL CUPOLAS. 173 The cupola will melt about 2,000 pounds of iron per hour, and eighteen charges, or 3,600 pounds can be melted at one heat. Two or three heats may be made the same day. The blast can be delivered from a small fan driven by belt or motor. The following are some of the advantages claimed for this cupola: A test chaige of ico pounds of iron will show the quality of any pig iron or mixture if the fire has burned two hours, that is, if the cupola is as hot as the average large cupola. On days when, from any cause, the large cupolas are not run, the foreman and his assistants can mold and take off two or three heats, and earn part if not the whole of their wages; and at the same time do work that is needed. Duiing any shutdown, repair castings can be made for quick " while you. wait " repairs. The iron may be ready to pour by the time a piece is molded. If an important piece is lost at the regular heat, it can be made the same night or early next morning. For special mixtures, such as white iron, chilling iion, semi-steel or soft iron for patterns, the results will always be as calculated. If molders break a heat, the cupola can be rolled in place and started before the men get out of the shop, and work that is needed can be made, so as to keep the rest of the shop running. As a result, very few heats are brtjken. For portable use by miners, contractors and technical schools, it recommends itself. This cupola may be mounted on a truck, as shown in illus- tration, or placed upon legs and made stationary if desired. In foundries with high roofs it may be charged fiom the top and no stack used, but the greatest advantage it presents fur very small cupolas is the sectional construction, which admits of the lining being repaired or renewed without going into the cupola. DIMENSIONS. c No. meter hell iside. meter iside iiiing. E >-5 H^ 1 -0 1 ■StS °J4 ^,2 s s E.2.2- 2 J- «-! .2"-! u ■4- .xta .2^-^ .2<:o &<-> •53 H lo .2*>"H P Q a D Q Q X n e 27K 27" 22" 8 ft. 27" 39" 10" 19" 4)^x10 7" 174 THE CUPOLA FURNACE. Fig. 41. STATIONARY BOTTOM CUPOLA. In Fig. 41 is shown the old-style English cupola. This cupola is constructed upon a solid foundation of stone or brick work and has a stationary bottom of brick, upon which is made a sand bottom. The refuse, consisting of ash, cinder and slag, remaining in the cu- pola after the iron is melted, is drawn out at the front in place of dropping it under the cupola, as is now generally done with the drop-bottom cupola. These cupolas are generally of small diameter. The opening in front for raking out is about two feet square, and when the cupola is in blast, is covered with an apron of wrought iron. When the cupola has been made up for a heat, shavings, firewood and a small amount of coke are placed in it and ignited, with the front open ; when the coke is well alight, a wall is built up with pieces of coke even with the inside of the cupola lining. Fig. 42. STATIONARY BOTTOM CUPOLA. SMALL CUPOLAS. I 75 The bed of coke is then put in, a round stick is placed in the spout to form the tap hole, and the front is then filled in with new molding sand or loam even with the casing, and rammed solid. The apron. Fig. 42, is then placed in position over the loam and wedged tight against it, to prevent it being forced out by the pressure of molten iron in the cupola. After the breast-plate is placed in position, the tap hole and spout are made up in the ordinary way. Some melters prefer to place the apron in position before lighting the fire, and put the breast in from the inside when making up the sand bottom. It is then rammed solid against the apron and made up to the full thick- ness of the brick lining of the cupola. When the heat has been melted the breast-plate is removed and the loam front dug out. After the loam front has been broken away, a sheet-iron fender is placed in front of the cupola to protect the workmen from the heat, and the raking- out process begins. This is done by two men with a long two-pronged rake. If the refuse hangs in the cupola, it is broken down from the charging door with a long bar, or by throwing in pieces of pig iron. These cupolas were extensively used in England, but never to any extent in this country. SMAIX CUPOLAS FOR BEDSTEAD WORK. The draw-front cupola has come into use quite extensively in the past few years as a bedstead foundry cujjola. This work is cast in chills placed in forms for the head or foot of a bedstead. After casting a form the castings are removed and pipes placed in the chills for another head or foot of a bedstead. This re- quires considerable time, and a cupola is theiefore desired that will melt iron slow and hot and may be kept in blast all day. This cupola possesses this advantage for, in case it becomes clogged, the front may be removed and the cupola cleaned out, a new front put in, and melting continued without waiting f6r the cupola to cool ofif, as with the drop bottom. In a bedstead foundry recently visited at Ansonia, Conn., we found one of these cupolas in use, with one tuyere 10 inches in diameter lo- 1/6 THE CUPOLA FURNACE. cated at the back of the cupola, with a removable blast pipe. When the cupola became clogged or bridged ihe blast pipe was removed, the front taken out, and through these two openings the obstruction in a few minutes removed with bars. A new front was then put in, fresh fuel charged, the blast put on and melting resumed in from twenty to thirty minutes from the time the blast w . o N 00 O lo o N • u^ O t^ H "* : o vn m . O »0 o na ^1 o ro N • o fO ro in \r% : »i-> " " , , , o Ul u in in t/i q K 0) U 1 4) lU tJD W bx M (M) 00 ex 5x M W) cu: M OX) ty; eac M tuo CUD <^ f c! C3 C5 CS ts c3 rt cl rt rt O .£ j: ^ jz ^^ ^ j; ^4=.C J3 jz M^ ^^js F-i (. <- o o c c c ^ «> ^ ^ 'A CQ • (A en en en c/1 en (u a> 3r biO bX) M tuo ao tn/} t> k. ^ t. >- 11 li CQ c4 <4 c^ c^ cd .C u u u u u u O "^ • tn tn tn tn cA in V D QJ ■L' (U Q> 4) cuo 0£ OX) wi or OX) tU3 >3 >- 1- ■ en en in in tn en J3 U U O U o tJ an ffia -OS 00 ■_ >_ o o 2 3 /'h 7> m o 0\ HJ . ,4_, o S . c! ON o • o j: , ON^ . ►" o • o a o XX WIS onS ■Pi; re o )J In O D . « P **-( ^ On " ^ ■" o . s in SXjS" ci -s t3 C >— , tn a< t. fcT ' 1> a -c ^^ S. . " in ea "^ T-I in 1^ S 6 rt ?! ii ;s ^ ^° 1) - o •■ -, „ u, -^ ii c ■■ -'^ .y ^.2 -^^ ^^^-^ a ^ u ^ Ji o " D "C ^ -- p/ t« y > CIS CO ^ "W CHAPTER XI. FREEZING THE BLAST, Since heating the blast for cupolas has thus far proved a failure, and will likely continue to be failure, owing to the limited time cupolas are as a rule kept in blast, the next field open for scientific investigation that promises any degree of success is freezing the blast to drive out any moisture it may contain. This method has been tried by blast furnace men with marked success in the saving of fuel, and the same results might be obtained in cupola practice, but we have not been able to learn of freezing the blast for cupolas having thus far been tried. There would be some difiference between this practice in fur- naces and that of cupolas, for in the former the blast is heated after having the moisture frozen out of it, which could not be done for the cupola. Many founders claim they obtain hotter iron with the same per cent, of fuel in the winter when the air is dried by being frozen than in summer when the air is laden with moisture. This being the case, a blast with the moisture all frozen out of it should produce a hot, fluid iron with less fuel than required in either summer or v\ inter. But this claim that hotter iron is obtained in the winter has never been proven, to our knowledge, by scientific investigation, and may only be due to the appearance of the molten iron in a ladle, which always appears hotter in a dark day of winter than in the warm, clear days of summer. The freezing of blast can readily be effected by passing it through a cold storage or artificial ice plant, as has been done by blast furnace men, and this may be tried by some of the larger foundry plants at an early day and a con- siderable saving efTected in fuel. But freezing plants are too expensive at the present time to be installed for freezing the (215) 2l6 THE CUPOLA FURNACE. moisture out of the blast for a cupola that is only in blast from one to two hours per day in melting a few ton of iron. MOISTURE IN BLAST. While hot and dry blasts for cupolas have received consider- able attention, the wet or moist blast has not been forgotten. For while it is claimed by many founders, that hotter iron is melted with the same per cent, of fuel with the cold dry air of winter as a blast, it is also claimed by others that hotter iron is melted on a wet day or in a damp atmosphere than on a dry, clear day, and many attempts have been made to produce a blast containing a per cent, of moisture equal to or above that of a damp wet day. Probably one of the most exhaustive ex- periments made along this line in this country, was that of The Lobdel Car Wheel Co., Wilmington, Del. This company constructed an underground air chamber, 50 feet long and 3 feet square, through which the blast was passed just before entering the cupola. At intervals of every few feet pipes were arranged across the whole length of this air chamber so as to throw a spray of water over the top and also to have the bottom of it covered with water. It was hoped by passing the blast through this chamber to add moisture to it, and obtain the hot fluid iron of a damp wet day with less fuel. But no reduction in fuel could be affected with this blast. A greater number of sprayers were then put in and the blast virtually forced through a very heavy rain storm, but this gave no better results. The air was then analyzed before entering the chamber, and after passing through it, to determine the per cent, of moisture it had taken up, and it was found that not one particle of moisture had been added to it in passing through the chamber. Steam was then tried in the air chamber with no better results in add- ing moisture to the blast, and the experiment was given up as a failure. These experiments were followed up in various ways until it was conclusively shown that moisture could not be added to the blast by any such device, but they failed to determine, whether the moist air of a wet damp day produced FREEZING THE BLAST. 217 hotter iron, than that of a dry day, for no moisture was added to the blast. Water has also been sprayed into the blast at the tuyeres, with a view of obtaining a moist blast, but this too proved a failure, as no saving in fuel was effected, or a perceptible im- provement in the quality of iron observed. Steam under low and high pressure has also been forced into the cupola at the tuyeres, together with the blast, for the purpose of giving a moist blast. Great results have from time to time been claimed for this process for improving the quality and strength of the iron melted, it being asserted that iron melt d with this process could be punched without cracking or breaking the same as wrought iron. But this claim failed to hold good, for in all cases, the same mixture of iron that can be punched without cracking, obtained by blowing in steam, can as readily be punched without steam having been used. Since writing the foregoing pages on dry and moist blast the following articles have appeared, together with comments by the editor, in the January, 1910, issue of " Castings." As these articles answer some of the problems of the foregoing pages and also present some new suggestions, they are here inserted for the consideration of the reader. Wealker and the Output of the Cupola * Why does the cupola melt better on a cold day in the winter than on a hot summer day? Why does a cupola melt better on a rainy day in the summer than on a dry day at the same season of the year? These are questions that are constantly being asked, and have puzzled many a foundryman. Both are easy of answer if we consider the underlying principles. Air Capacity for Moisture. — As a given volume of air is heated at constant pressure it expands and at the same time its capacity for moisture is very greatly increased. In locations near the sea or where there are considerable bodies of water to * By M. H. Bancroft. 2l8 THE CUPOLA F"URNACE. draw from, air is usually fairly saturated with moisture. The table below gives the weight of a cubic foot of air at several temperatures and also the amount of water contained in the air at these temperatures. The figures given in this table correspond to a barometer reading of 29.921 inches of mercury, the ordinary reading at the sea level. If air at a relatively high temperature and satu- rated with moisture is suddenly cooled, the moisture will be precipitated as rain or dew if the temperature is above 32 degrees Fahr., and as snow or frost if the temperature is below 32 degrees. Air that is almost saturated seems dry to us, while that which is supersaturated seems moist and in the lower temperatures colder than it actually is. In temperatures that approach bloodheat, very moist air seems hotter than is really the case. EFFECT OF HEAT ON AIR. Temperature in degrees Fahrenheit. W I eight of air in cubic foot in pounds. .0863 32 .0802 62 .0747 82 .0706 92 .0684 Pounds of water in I cubic foot. ,000079 .000304 .000887 .001667 .002250 Total number pounds of air and moisture. .086379 .080504 .075581 .072267 .070650 Weight of Air and Amount of Entrained Water at Various Temperatures. Let US now investigate the efifect of the varying degree of moisture and also the effect of changes in the density of air due to variations in the temperature. Between zero and 92 degrees Fahr. the expansion of air as shown in the table has reduced the weight of a cubic foot 26 per cent, in terms of the higher temperature. At the same time the amount of moisture which air can carry has been increased 27 ^/^ times. FREEZING THE BLAST. 219 Air is always supplied to a cupola by a fan or blower which, under given conditions and in a stated length of time, delivers a definite volume of air. Any change in the density of air will therefore affect the amount of oxygen entering the cupola and any alteration in the amount of water the air carries will also have its effect on the combustion. Whatever enters the tuyeres must pass through the fire. Water that goes in as an invisible vapor will dampen the fire just as effectively as an equal amount introduced from a hose. Load on Blower or Fan. — If we compare the combined weight of a cubic foot of air and the moisture it contains, we find that between zero and 92 degrees Fahr. there is a difference of .01 5662 pound per cubic foot. This is a change of 22 per cent, in the weight of a cubic foot of air and its contained moisture when compared with the weight at the higher temperature. In other words, at zero degrees Fahr. to pass a given number of cubic feet of air a fan or centrifugal blower must do 22 per cent, more work. These is another factor, however, which neutralizes this effect to a considerable extent. Owing to the greater density of the air the fan has a tendency to slow down as the load increases, and also owing to the greater density the amount of oxygen introduced at the lower temperature is greatly increased. In comparing the amount of moisture introduced at different temperatures we will consider the temperatures of 32 degrees and 92 degrees, the object being to eliminate the influence of the freezing point from our calculations. When a pound of water at 32 degrees Fahr. is heated, it ab- sorbs an amount of heat known as a British thermal unit for each degree's rise in temperature. To raise one pound of water from 32 degrees to the boiling point, 212 degrees, would re- quire 180 British thermal units. When the water reaches the boiling point it is converted into steam, but while this phenomenon is going on a great deal of heat is used up without increasing the temperature. This is known as the latent heat of vaporization, and represents the 220 THE CUPOLA FURNACE. energy expended in changing water to steam. To change one pound of water from a fluid at 2 12 degrees to steam at the same temperature requires 965.7 British thermal units (^com- monly abbreviated to B.t.u.). Temperature of the Air. — After the moisture has been con- verted into steam its specific heat is .48. In other words, it takes .48 of a B.t.u. to make a rise in temperature of i degree in a pound of steam. For clearness and to save dealing with very small figures, we will consider the amount of moisture in i,oco cubic feet of air at 32 degrees Fahr. This is .304 pound, while at 92 degrees it is 2.25 pounds. The amount of heat necessary to raise the moisture in 1,000 cubic feet of air at 32 degrees Fahr. to the temperature of the melting point in a cupola, which for these calculations is taken at 2,700 degrees Fahr., is shown by the following calculation : .304 X 180 = 54-72 B.t.u. required to raise the moisture from 32 degrees to the boiling point. .304 X 965.7 = 293.57 B.t.u. required to convert the moist- ure into steam. .304 X 2,488 X .48 = 363.05 B.t.u. required to raise the steam from 212 degrees to 2,700 degrees, or a total of 711.34 B.t.u. We will next consider the amount of heat necessary to raise the moisture in i,coo cubic feet of air at 92 degrees to the melting point of iron. These calculations are as follows: 2.25 X 120 = 270 B.t.u. required to raise the moisture to the boiling point. 2.25 X 965,7 = 2,152.82 B.t.u. required to convert the moisture into steam. 2.25 X 2,488 X .48 = 2,687.4 B.t.u. to heat the steam from the boiling point to the temperature of the melting zone in the cupola. This makes a total of 5,109.86 B.t.u. The difiference be- tween these two figures amounts to 4,398.52 B.t.u. Ratio of Air and Coke. — Most foundry coke averages about 10 per cent, ash, or stated the other way, about 90 per cent. FREEZING THE BLAST. 221 carbon. To burn this carbon would require 129.6 cubic feet of air at 32 degrees Fahr. In most cases, however, owing to the fact that some air escapes up past the charge along the lining and that the combustion is not uniform throughout the charge, a slight e.xcess of air has to be added. A 10 per cent, excess brings our figures up to 150 cubic feet of air to burn a pound of coke. It is probable that in practice somewhat more than this proportion is used. If we consider a melting ratio of 8 to i, it will require 250 pounds of coke to melt the 2,000 pounds of iron. By multi- plying the weight of coke by 150, we conclude that it will take 37.500 cubic feet of air to melt the ton of iron. Temperature of Moisture. — Of course if the melting ratio is higher, it will require less air. If it, is lower we will have to blow a greater amount into the cupola. If we refer to our former figure, which gave the B.t.u. necessary to raise the moisture in t.ooo cubic feet of air from 92 degrees to the tem- perature of the melting zone in a cupola, we see that this figure is 5.109.86. If we divide this by i, coo, to obtain the amount of heat necessary to raise the moisture in one pound of air to the tem- perature mentioned, we find that it is 5.109, or approximately 5.1 1 B.tu. Waste Heat. — Multiplying this figure by 37,500, the amount of air required to melt one ton of iron, we ascertain that we are wasting 191,625 B.t.u. by having to heat the moisture which enters with the air. One i)ound of the best coke contains 14,500 B%t.u. Divid- ing 191,625 by 14,500, we discover that it requires over 14^ pounds of coke simply to take care of the moisture which is introduced to melt a ton of iron under ordinary summer condi- tions. In the winter we are introducing one- seventh as much moisture and it will require less than two pounds of coke to take care of the moisture in the air which wc introduce to melt a ton of iron. Coke ill Summer and Winter. — In other words, if we use a 222 THE CUPOLA FURNACE. given weight of coke which is sufficient to melt a ton of iron in the summer, in the winter we have about ii pounds of coke to each ton of iron which is used for superheating the iron or which may be used for melting an excess quantity. This 1 1 pounds of coke in the winter would be capable of melting over 88 pounds of iron at the ratio which we have taken and would produce it at the same temperature that the cupola delivered its product in summer weather. The reason why a cupola works better on a rainy day in the summer than on a dry day, is simply that a rain cannot occur without a falling temperature. The falling temperature reduces the amount of water which a given volume of air can contain and thus reduces the amount of moisture entering the cupola. This in turn sets free some of the coke and allows it to super- heat the charge. Moist or Dry Cupola Blast* Many founders are of the opinion that hotter iron is melted on a wet, damp day when the atmosphere used as blast is laden with moisture than can be melted on a dry clear day with the same per cent, of fuel. They attribute this result to moisture or water in the blast. Numerous attempts have been made to add this moisture to the blast in drj' weather, such as passing it through a spray of water or steam just before entering the tuyeres. Adding Steam or Water to Blast. — These attempts have failed owing to the failure of the blast to absorb moisture as shown by analysis of the air, before and after passing through the spray. With the same object in view, water has been sprayed into the tuyeres with the blast. Steam has also been introduced in the same way, but without any perceptible sav- ing of fuel or improvement in the quality of the iron. Another claim made by many foundrymen is that the dry blast of winter, from which the moisture has been frozen, pro- duces a hotter iron than the moist blast of summer. I have * By Dr. Edward Kirk. FREEZING THE BLAST. 223 never learned of any attempt having been made to freeze the moisture out of the air for a cupola blast, though this has been done with marked success, and a sufficient saving in fuel to pay for the installation of a freezing plant in blast-furnace practice. A similar saving should readily be effected in cupola practice. Climate ajtd Hot Iron. — It has occurred to me that these two directly opposite theories might readily be tried out in the various climates of this country and Canada without any outlay for plant or special devices. In the north and northwest, we have a temperature for several months in the year sufficiently low to freeze the moisture all out of the air. This is followed by the warm months of summer with a moist air. A careful test made of the amount of fuel required to melt a given amount of iron in the winter and then compared with that necessary to melt a similar heat in the summer, should readily determine if any less fuel is requisite with the cold dry air of winter, than is essential with the moist air of summer, and if the saving of fuel is sufficient to pay for the installation of a freezing plant for an ordinary-sized foundry. Then again, we have the wet and dry season of California where the moist or wet blast theory could be tested in the same way. A series of accurate tests might not only result in settling the question of which of these theories is correct, but also in considerable saving of fuel to the tester and a great benefit to the foundry industry of the country. Dry Air for the Cupola* The Gayley dry blast has become an approved and regular factor in the economical manufacture of iron in blast-furnace practice. What has been published on this subject has un- doubtedly set many foundrymen to considering the cupola and the effect of moisture upon its action. Elsewhere in "Castings" we publish two articles that show the trend of thought among our readers. One of these essays * Comments by the Editor of " Castings." 2 24 THE CUPOLA FURNACE. is entitled " Weather and the Cupola," and is by M. H. Bancroft. It is a critical discussion of the subject from a simple mathe- matical point of view. The other contribution, on " Moist and Dry Cupola Blast," is by Dr. Edward Kirk. In this aiticle the doctor points out that by carrying on experiments in the wmter and then dupli- cating them in the summer, definite information as to the value of dry blast for the cupola can be obtained. Mr. Bancroft, however, brings out some points in his article which answer sundry of the queries in Dr. Kirk's essay. The former emphasizes the ratio of air and moisture, and shows that air which may seem dry is in reality (relatively) moist. Of course the relative humidity of certain parts of the United States, as for instance, southwestern and southern California, would have a marked effect upon this problem. In these sec- tions the air may be exceedingly dry during what is known as the dry season. This dryness is so marked that at times there is no dew at night even though there is a marked falling tem- perature. That proves conclusively that the air during the day contains a very small proportion of the moisture which it is capable of carrying. Most of the foundry plants in the United States, however, are located in the relatively humid eastern central states. From Mr. Bancroft's article it is evident that a considerable saving in fuel would be effected if a furnace could always be supplied with dry air. From this circumstance it would be a comparatively simple matter for heavy mclters to calculate the saving which could be effected by installing refrigerating plants for removing the moisture from the blast during the summer months. Dr. Kirk calls attention to the fact that air conducted through a spray of moisture had no more moisture after leaving the spray than before. Air so treated may contain less moisture, after passing through the spraj-, because the water cools it and reduces its capacity for carrying moisture. CHAPTER XII. CUPOLA FUELS. In these da}'s of advancement in foundry practice the sub- ject of cu])ola fuel is frequently referred to in several scientific papers, and inquiries in regard to the use of various fuels are frequently made, with a view of reducing the cost of fuel and doing more economical melting. Coke, when of good quality, is undoubtedly the best cupola fuel. With it iron may be melted rapidly and of any degree of heat desired for the work to be cast. It therefore possesses or gives the two requisites of modern foundry practice: Rapid melting and hot fluid iron. But all coals do not make good cupola coke, and foundries located nt a great distance from the foundry coke centers frequently find that the cost of transpor- tation makes their coke very expensive, and as the saying is, " costs its weight in gold." These are the founders who are looking for a cheaper and better cupola fuil. The latter, we fear, will be hard to find, but the former may be had, and a few recollections of meltnig done when cupola fuels were not so perfect as today and of experiments made with various fuels may be of interest. GAS AND LIQUID FUFL. The question is frequently asked : Why cannot iron be melted in a cupola for foundry work with gas, such as natural gas, illuminating gas; or liquid fuel, such as petroleum, oil, benzine, gasoline, etc., more economically than with coal or coke ? The reason these fuels cannot be used in a cupola is that the latter is constructed upon the principle of melting iron in direct contact with the fuel consumed in melting it. Iron, when first reduced from a solid to a molten state in a 15 (225) 226 THE CUPOLA FURNACE. cupola, is not sufficiently fluid to flow into a mold, and must be superheated and made more fluid than when first melted be- fore it can be used for foundry work. And a cupola fuel must be of a suff.cient density to support the iron when melting, and to superheat it to a sufficient extent before dropping to the bottom of the cupola to run the work to be cast. Gas and liquid fuel possess sufficient heat-producing units to melt iron in a cupola, but they are deficient in the requisite supporting properties of a cupola fuel. And iron, when melted by them, drops as soon as melted to the bottom of the cupola, where it cannot be sujierheated, or at least has not been super- heated by any plan yet devised. The writer, like many others, conceived the idea of melting iron in a cupola with these fuels many years ago, and in 1878 laid his plars for doing so before Mr. John S. Perry and Mr. Andrew Dickey, of the Perry Stove Co., two of the most ad- vanced men in foundry practice at that time in this country. They thought the plan feasible, and offered me every facility of their foundry plant, at Sing Sing, N. Y., for melting iron with any of these fuels I might select. A small cupola was constructed with numerous small open- ings or tuyeres, through which a blow-pipe flame could be thrown upon the iron. At each of these openings a lamp filled wiih kerosene oil was placed, and the flame from the burner directed upon the iron by means of blow- pipes connected with a main blast-pipe supplied by a fan-blower. By this means it was hoped to melt iron as rapidly in a 12- or 18-inch cupola as it could be melted in a 60- inch cupola with anthracite coal. For the first test a bed of coal was put in up to the first row of tuyeres to support the iron and keep it ofT the sand bottom. When. the coal was well burned iron was charged, and the numerous blow-pipe flames were directed upon it through the tuyeres. The iron was rapidly melted in this test by the blow- pipe flames, but was not sufficiently fluid when drawn from the tap hole to be cast. CUPOLA FUELS. 22/ To overcome this difficulty the melting zone, which had only been about one foot in depth, was increased to four feet, and an increased number of blow-pipe flames directed upon the iron. This caused the iron to be melted more rapidly, but did not increase its temperature or make it more fluid, but rather decreased its fluidity ; for the rapid melting increased the body of molten iron passing through the bed of coal, causing it to pass through more rapidly, and it was not superheated by the bed to the same extent as when the melting was not so rapid. After a number of failures in this line to produce a hot iron, it was decided to abandon the lamps and convert the oil into gas with a view of getting a hotter flame. A retort was cast and after being properly connected with the cupola was charged with crude petroleum, and the flame from the gas generated directed upon the iron by means of the blow-pipe as before throughout a four-foot melting zone. This plan melted the iron rapidly, but like the other, failed to produce a hot fluid iron. A bed of coal was then placed in the cupola and a light blast put on for the purpose of superheating the iron, after being melted with the gas. This plan produced a hot fluid iron, but after superheating a limited amount of iron the bed became exhausted and the only way to replenish it was to draw off all the iron, shut off the gas and put in a new bed. The fresh bed had to be heated and the temperatute of the melting zone brought up to the melling point before melting could be resumed. This resulted in considerable loss of time and waste of fuel in melting and was not considered practicable. The blow-pipe theory was then abandoned and a series of pipes placed in the melting zone, for the purpose of super- heating the gas before burning it and creating a more intense heat than we had yet obtained. This plan melted the iron, but as before failed to produce a hot fluid iron, and the pipes in a short time became so choked with carbon that the gas failed to pass through them and melt- ing stopped. This difficulty could have been overcome to a 228 THE CUPOLA FURNACE. sufficient extent to prevent the formation of carbon in them, but the iron melted was not satisfactory, and this plan was abandoned. After these repeated failures Mr. Perry, Mr. Dickey, and their entire foundry staff were consulted as to how a hot iron could be obtained in melting with these fuels, and a number of plans suggested by them were tried, all of which proved fail- ures. It was finally decided that a hot fluid iron could not be melted in a cupola with these fuels, no matter how hot the melting zone might be made, for the reason that the iron when melted dropped through the melting zone so rapidly that it could not be superheated. Since these experiments I have been called upon several times to assist in devising a plan to melt iron in a cupola with these fuels, and have learned of other experiments having been made, all of which proved failures. So far as I know, iron has never been melted in a cupola sufficiently hot and fluid for general foundry work with any of the gases or liquid fuels. Iron may be melted for foundry work with these fuels in furnaces especially designed for their use. Brass and other metals may also be melted with them in a properly constructed furnace for using them. One of the latest and most successful experimenters in design- ing and constructing furnaces for the melting of metals with oils and gases is W. J. Brown, Philadelphia, Pa , and founders favorably located for using such fuels may gain further infor- mation on the subject by addressing the J. W. Parson Co., Philadelphia, who are handling the furnace. CHARCOAL FUEL. The first fuel that was used in this country in smelting iron from its ores and also in cupola practice was charcoal, and for many years it was the only fuel available for these purposes. It produced a superior iron in many respects to that obtained with fuels in general use at the present time, but with the increase in population and disa{)pearance of the forests, char- CUPOLA FUELS. 229 coal is no longer available for this purpose ; except in moun- tainous districts where land is worthless for any other pur[)ose than the growing of timber, or in thinly populated districts where the forests have not yet been destroyed. Such districts are generally located a long distance from the cupola fuel centers, and a few points on cupola practice with charcoal fuel may be of interest to foundrymcn situated in these localities, and also to others who are unable to get a satisfactory iron with other fuel. My experience in melting with this fuel in cupolas has been limited to small cupolas of from 20 to 30 inches inside diam- eter. But the fuel will carry as heavy a burden in a cupola as in a blast furnace, and is therefore available in melting in any sized cupola up to that of a charcoal blast furnace, which will include the largest cupolas now employed in the melting of iron for foundry work. When melting with charcoal the fuel and iron are placed in the cupola in charges, in the same manner as when melting with coal or coke. A sufificient quantity of shavings, straw, or other combustible material to ignite the fuel is first placed in the cupola. Upon this a layer of small, soft wood, and upon this a bed of charcoal extending to from iS to 20 inches above top of tuyeres. Upon this a charge of iron, then a charge of charcoal, and upon this a charge of iron, and so on until the entire heat to be melted is placed in the cupola. As charcoal is light and readily combustible, it is customary to fill the cupola with stock before lighting the fire, and to avoid wasting the fuel, to put on the blast as soon as the char- coal has become ignited, and there is a good fire in it at the tuyeres. Charcoal does not carry as heavy a burden as coal or coke, and the charges of iron are made lighter and more numerous than when melting with these fuels. The weight of charges of fuel and iron is varied to suit the volume of blast, which should be lighter than when meliing with the harder and less freely combustible fuels. 230 THE CUPOLA FURNACE. The charges of fuel are made about 6 inches in depth or thickness, and the largest amount of iron which can be melted at a charge is the amount that can be melted without reducing the bed to such an extent that the next charge of fuel will not replenish the bed and bring it up to the top of the melting zone for melting the next charge. When charges of fuel and iron are properly proportioned iron may be melted sufficiently hot to run the lightest of cast- ings at a ratio of fiom 3 to 4 pounds of iron to a pound of fuel. It has been found in furnace practice that the best charcoals for fuel are made from the hard woods, and from small timber rather than from the large, and the second and third growth small, hard timber makes a charcoal that will carry a heavier burden and last longer than charcoal from first growth timber. Small cedar timber makes a very good fuel charcoal, and is the principal wood used for this purpose in some sections of the south. There are sections of this country where more economical melting can no doubt be done with charcoal than with coal or coke, but the results obtained when melting with charcoal are not to be compared to those obtained with either of the above fuels when fast melting and hot iron are desired. ANTHRACITE COAL AS A CUPOLA FUEL. The principal mines of this coal are located in four counties of eastern Pennsylvania, and the known area of the anthracite fields at the present time is 472 square miles, and the output of coal about 75,000,000 tons annually. Outside of these four counties in Pennsylvania there are only three anthracite coal mines in the United States, one in Colo- rado, one in New Mexico, and the third in Rhode Island. The aggregate output of these three mines is only about 60,000 tons per year, and the coal is a poor sort of anthracite. The Pennsylvania hard coal fields are divided locally into four regions, the Lehigh, the Schuylkill, the Lackawanna, and the Scranton. These various fields produce different grades CUPOLA FUELS. 23 I of coal. That of the Lackawanna and Scranton regions is soft compared with that of the Schuylkill, and that of the Schuyl- kill soft compared with that of the Lehigh region. There is also considerable difference in coal from the various mines in the same region. That from the deeper vems is gen- erally harder than that from veins nearer the surface. As a cupola fuel, in the days of anthracite fuel, coal from the Lehigh region ranked first, Schuylkill second, and that from the other two regions third. Coal from various mines in these regions also had higher reputations than that from others. Of all the mines Old Mine Lehigh had the h'ghest reputation as a cu{)ola fuel. This coal was of a bluish cast of color, very hard, and when placed in the sun in large pieces presented all the colors of the rainbow. Coals from other mines in this region have the same character- istic to a greater or less extent, but that from other regions is generally of a black cast of color, and the softer the coal the blacker it is in the fresh fracture. Some years ago when the largest pieces of coal that could be placed in a cupola were considered necessary for a good bed, these indicatii>ns of the qualify of a coal were considered of importance, as they enabled the expert foundryman to judge at a glance the quality of the fuel. But at the piesent time little or no attention is paid to ihem. There are no records to show when this coal was first used as a cupola fuel, but there are records to show that the first mine in the Pennsylvania districts was opened in 1810, and the output of coal in that year was 3C0 tons. It was probably about this time that the coal began to replace charcoal as a cupola and blast furnace fuel. How many years were required to introduce it for this pur- pose is not known, but one thing is certain, that it became the universal cu{)ola fuel in all the eastern sections of the country and as far west as it could be obtained. In 1875 I found it in use in many of the foundries in St. Louis, Chicago, Milwaukee, and various parts of Canada, and all the eastern section of the country. 232 THE CUPOLA FURNACE. In the early days of the manufacture of coke, coal from almost any of the anthracite coal fields of Penns)lvania was considered superior to coke, but with the improvements made in the manufacture of coke from time to time coal has been comptlkd to give place to coke, until at the present time the use of coal as a cupola fuel is restricted almost entirely to the coal fields and near-by foundry districts where it can be ob- tained at a less cost than ccke, and to foundries a long di^tance from the coke centers, to which coal is delivered by vessels at a less cost per ton of iron melted than coke, and its use has become so restricted that we are compelled to write of it rather as a cu| ola fuel of the past than of the present. To illustrate the manner of charging and melting with coal from the different coal fields of Penns}'lvania, 1 have selected from my notes three heats of about the same size melted in different sections of the country in which these fuels were most commonly used. The first of these was melted March 25, 1876, with Lacka- wanna coal at the foundry of Jackson & Woodin, Berwick, Pa., a small town located near the Lackawanna or Wyoming coal fields. The iron was melted for car wheels and general car castings, and was not lequired to be very hot to run the work: Bed Coal 1900 Charge Iron 435° Charge Coal 5C0 " " 435° ^co " '• 4350 7C0 " " 435° Total Coal 37CO Total Iron 1 7400 Per cent, fuel 21.2b -\-. Heat melted September 26, 1876, with Schuylkill coal at the foundry of the American Stove and Holloware Company, Philadelphia, Pa. The iron was used in the casting of stove plate and hollow ware, and required to be very hot and fluid to run the work : CUPOLA FUELS. 233 Bed Coal 1 500 Charge Iron 4000 Charge Coal 350 " " 4C00 350 " " 4CC0 350 " " 4000 250 " " 20CO Total Coal 2800 Total Iron 1 8cco Per cent, tuel 15.55 + . Heat melted January 15, 1877, with Old Mine Lehigh coal at the foundry of the Wolf Stove Work-, Troy, N. Y. Very hot fluid iron for light plate was melted in this heat. Bed Coal 1400 Charge Iron 4000 Charge Coal 500 " " 4000 300 " " 4C00 250 " " 3000 250 " " 3100 Total Coal 2500 Total Iron 18100 Per cent, fuel 13.81. It will be observed that the weight of fuel in the first heat is increased each charge and the charges of iron remain the same throughout the entire heat, while the weight of fuel in the charges with the harder coal remains the satne as long as the weight of iron remains the same, and is decreased as the weight of iron decreases. In melting with coal it has been found that with the softer coals the bed gives out in a long heat, resulting in dull iron towards the latter end of the heat. To obviate this the charges of fuel are increased to keep up the bed and prevent iron settling too low in the melting zone before melting. Ihis is the mode of charging commonly fol- lowed when melting with soft coal. It will also be observed that the per cent, of coal consumed in melting varies to a considerable extent. This is due in these heats to the quality of coal. This variation always occurs with the difTerent coals under the most favorable conditions, and is due to the difference in the heat-producing units of the coal. 234 THE CUPOLA FURNACE. The following reports from fourteen large foundries located in different parts of the country and using different grades of coal show the per cent, of coal consumed in melting for one year to have been 15.55, M-S f » I5-I7. 17-22, 16.12, 15.08, 15.48. 14.70, 14.95, 18.10, 20.00, 18.72, 20.39, 19.78. The foundries are principally stove-plate foundries and foun- dries casting light work for which very hot iron is required, and they show the average melting done in well-regulated foundries of this class. Founders and melters who are accustomed to speaking of pounds of iron m.eltcd to the pound of fuel may at first glance, as we have known them to do, take these figures to mean pounds of iron melted with a pound of fuel, which is not the case. They represent the pounds and fraction of a pound of fuel consumed in melting one hundred pounds of iron. Prior to the dates above given every foundry appears to have been a mystery unto itself, and nothing was published in regard to cupola fuel, and it was only by promise of absolute secrecy as to the founder furnishing them that these figures were obtained. Prior to this date, and even at the time, it was the practice in many foundries to use in melting the largest pieces of coal they could obtain or place in the cupola. Such coal was con- sidered necessary to make a bed that would last through a heat of two or three hours. I have seen the largest pieces of coal a man could lift and place in a cupola put in for a bed, and low cupolas of frorrr eight to ten feet filled with wood almost to the charging door to ignite these large pieces of coal; smaller pieces were used for charging, but they were generally entirely too large for this purpose. This large coal did not make a compact fire, and large crev- ices or openings were left between them, through which the molten iron quickly dropped to the bottom of the cupola with- out being superheated in its descent, and it was only by using an excessive amount of coal that hot iron could be made. The CUPOLA FUELS. 235 average melting done with this kind of fuel, when hot iron was required, was from three to four pounds of iron to the pound of fuel with the best of coal. Later on it was the practice in many foundries to put in a bed of large coal and charge with small coal ; this gave a better per cent, and the average melting was from four or five to one. The writer was probably the first to call foundrymen's atten- tion to this mi.stake in using coal, and while it is claimed by many that a cupola cannot be run by a book, my early work on cupola practice certainly revolutionized the use of coal in many sections of the country. At the time it was published many old founders and melters ridiculed the idea of melting with small coal, and were so posi- tive it could not be done that numerous bets of from one hun- dred to five hundred dollars were offered that it could not be done, and a long heat melted or hot iron made. But these primitive ideas of using coal soon gave way to better judgment when once their attention had been called to the matter, and the use of small coal became universal. Iron may be melted in a cupola with any size coal from the smallest to the largest if the quality of coal is good. The best results are obtained in either small or large heats with broken coal about the size of the fist or of the two fists, and no larger coal should be used either for large or small cupolas. After the adoption of broken coal for melting, the per cent, of coal required for making hot iron was very much reduced, and the average melting in well managed cupolas in large and small heats was from five to seven to one, and in some cases as high as seven and a half was obtained. This was probably the best ever done, although there were founders and melters who claimed as high as ten to one, but I have never seen any such melting done either in regular or test heats, and men doing such melting probably did it in their minds, as many do at the present time who melt with a very small per cent, of coke. When coke was first introduced into the coal melting districts 235 THE CUPOLA FURNACE. of the eastern section of the country, many founders were afraid to use it in their cupolas, and it was introduced by mixing it with coal, or by putting in a bed of coal and charging with coke and coal, and this practice is still kept up in many foun- dries where the two fuels can be obtained at the same price per ton of iron melted ; it being claimed that a coal bed lasts longer than a coke bed, and also a mixture of the two fuels in the bed and charges makes a hotter iron and gives life and fluidity to the molten iron. There is nothing in any of these claims, for a bed of one fuel will last as long as the other, and as hot, fluid and lively iron can be melted with one fuel as with the other, or with a mixture of the two fuels. Another claim made for the mixture of the two fuels is that more rapid melting can be done and larger heats melted with mixed fuels than with coal alone. There is some truth in this claim, and founders melting with coal can do more rapid melting and may increase the melting capacity of their cupolas by mixing the two fuels in the bed and charges or in the charges alone, or by putting in a bed of coal and charging with coke. The following heats melted with mixed fuels will illustrate the manner of charging and melting with the two fuels: Heat melted in a 48-inch Colliau cupola with No. 6 Baker blower, tuyeres 18 inches above the bottom, Schuylkill coal and Connellsville coke used in melting. Iron melted for gen- eral machine castings. Bed Coke Bed Coal Bed Iron " 1200 « 600 >( 4000 Charge 250 Charge 100 Charge 4000 " 250 (( 100 4000 « 250 « 100 4000 " 250 (( ICO 4CC0 " 250 M ICO 4000 " 250 " ICO 4000 " 250 " 100 4000 '* 250 Total, 100 Total, 4000 Total, 3200 1400 36000 Fer cent, coke -; 88 4 Per cent, cnni 8.88 Per cent, fuel 12.77. CUPOLA FUELS. 23/ Heat melted in 54-inch Whiting cnpola with No. 6 Baker blower, tuyeres 18 inches above bottom, Schuylkill coal and Connellsville coke used in melting. Iron melted for light mal- leables and required to be very hot. B< *d Coal Bed Coke Bed Iron ' 2800 « eo " 3-'00 Cha rge I qo Charge 60 Charge 19CO 150 50 1900 150 5° 1900 150 50 « 1900 150 50 19CO 150 50 19CO 150 50 1900 150 50 ( 1900 150 50 1900 150 " 50 1900 150 50 19CO 150 50 1900 150 50 19CO 150 Total, 50 1900 To tal, 4900 770 Total, 298CO Per cent, fuel 19.02. Per cent, coke 2 58. Per cent, coal 16.44. In the first heat, the per cent, of coke predominates and was employed to do f.ist melting. The coal was used to give more body to the fuel and make hotter iron. In this case, the coke in the bed and charges was put in first and the coal on top of it. In the second heat, the per cent, of coal predominates, it being the cheaper fuel in this instance, and the small per cent, of coke was employed to make the cupola work more open and free. In this case, the coke was put in on top of the coal, as is generally done when coke is used for this purpose. The two fuels are also used in various other ways. In some foundries a bed is put in entirely of coal and charging done with coke alone, in others the bed is made of equal parts of coal and coke and the charges of the same proportions. In such cases it is the practice to put in the coke first and the coal on top. Coal, unlike coke, is useless as a fuel after it has been sub- 238 THE CUPOLA FURNACE. jected to the intense heat of a cupola and cooled again, although the coal when broken appears to be as good in the center as before heating. I do not know of any analysis having been made to determine the cause of this; but it has been demon^trated that it cannot be burned alone in a core oven furnace or in a heating stove, and when mixed with fresh coal tends to deaden the fire and decrease the heat rather than increase it; and when placed in the cupola with fresh coal probably produces no heat. It does not pay to recover such coal from the cupola dump for healing purposes. CUPOLA COKE. From a paper entitled "A History of Connellsville Coke," prepared by Mr. F. C. Kieghley, and read before the Central Mining Institute of Western Pennsylvania, it appears that coke was first made in this country in 181 7 at Plumsack, Fayette County, Pa , for rolling-mill use. In 1837 F. H. Oliphant made coke at his Fairchance Fur- nace, near Uniontown, Pa. All the early coke was made on the ground, in what was known as coke rickets. The first coke made in ovens was in about 1841. In that year Province McCormick and James Campbell, two carpen- ters, and John Taylor, a stone mason, commenced making coke with two ovens, and in the spring of 1842 had enough coke stacked to fill two boats, or about 800 bushels, which they took down the river on a high stage of water to Cincin- nati, Ohio. This appears to have been the first shipment of coke as an article of commerce of which there is any record. A part of this cargo was afterwards boated by canal to Dayton, Ohio, and was there sold to Judge Gebhard, a former resident of Pennsylvania, who then had a foundry in operation at Dayton. He used the coke in his establishment and found it so well adapted for his purpose that he afterwards came to Connells- ville and proposed to Campbell and McCormick to make more. This appears to be the first record of Connellsville coke hav- CUPOLA FUELS. 239 ing been used in a foundry, for in a long research I have been unable to find any record of it having been used prior to this date; but it is likely that coke was used in foundries prior to this date. For in the early days it was the custom of foundiy- men to make their own coke, and this practice was still in vogue in the sixties; and as late as 1863 the coke ovens of the A. Bradley Stove Works of Pittsburg, Pa., were still stand- ing in the foundry yards, although they were not in use at that time. At a still later date we have seen foundrymen making their own coke at a distance from Pittsburg, and it was not until late in the sixties that it became the general practice of foundrymen to buy their coke, even in the vicinity of Pittsburg. It was the practice for two or more foundries in these days to build a coke oven together, and either make their coke to- gether or take turns using the ovens. I remember when a boy going to school, one of these ovens built at Sharon, Pa., by William McGilvery & Co., and Joseph King & Co. It was located in Pine Hollow, near the Jennie Berg Hill, alongside of a tram road, constructed to carry coal from the mines for ship- ment by the canal, and was only in operation occasionally, when a supply of coke was required by either foundry. When in operation in the winter the boys always went to this hill to coast and get warmed at the coke oven, and many times have I warmed my shins at the old coke oven, when a boy. Later on, when a moulder in the employ of Joseph King & Co., I learned the history of the oven, which was re- moved in 1867, after having been abandoned for a number of years, when the supply of coke was received from Pittsburg and known as Pittsburg coke, made from Pittsburg coal. At that time there were numerous coke ovens along the Monon- gahela River and Allegheny Valley Railroad, employed in manufacturing foundry coke, which was known as Pittsburg coke. Later on, Connellsville coke came upon the market, and about 1870 or '71 completely replaced the Pittsburg coke as a foundry fuel. In these various cokes may be traced the advancement made 240 THE CUPOLA FURNACE. in the manufacture of coke. That made at Sharon was a soft, dark coke, weighing about 32 pounds to the bushel. Pittsburg coke was a denser coke of a dark color, weighing 46 pounds to the bushel. Connellsville coke was of a light color, and when put upt)n the market in its early days, weighed 46 pounds to the bushel. The manufacture of this coke has been improved until we now have it of a silvery white, weighing as high as 72 pounds to the bushel. Another coke that had a high reputation in early days was Blossburg coke, made at Blossburg, Pa. The supply of this coke was limited and it never came into general use, and I do not remember ever havmg used it in m.elnng. Numerous other foundry cokes have been put upon the market at various times, but they have, so far as 1 have been able to learn, proven f.iilures to a greater or lesser extent. Among these were Hocking Valley coke and othei;s made from Ohio coal. The cause of failure was due to the large per cent, of sulphur in the coal, which was not removed in the process of coking and could not be removed by various plans tried for washing the coal and preparing it before coking, or by devices in the construction of ovens for its removal. When engaged in the foundr)' business in Ohio in 187 1 a coke oven was constructed at Urichsville, Ohio, and I was given a half-carload of this coke to try it. The coke had the appearance of being a good foundry coke, but when tried in the cupola hardened the iron to such an ex:ent that the casting was worthless, and after a number of attempts to use it by changing the mixture of iron it was condemned. Other founders who were induced to try it had about the same ex- perience with it, and when passing the oven a few years later 1 found it abandoned and a complete wreck. No coal has yet been found in this country equal to the coal of the Connellsville coal region for the manufacture of coke. This region has become the great manufacturing coke center of this country and the output has increased from that of a few ovens to thousands, amounting to millions of tons of coke CUPOLA. FUELS. 24 I annually, and probably ninety per cent, of all the foundry coke used in this country at the present lime is Connells\ille. It carries a heavier burden in a cupola and melis iron more rapidly than any other coke. It is said to be freer from im- pu'ities detrmiental to iron than other cokes, and is the mc^st economical fuel for the cupola, although the cost of transporta- tion niay render it expensive. When this is the case the question of economy when melting must be con^idcred by the founder, and I shall endeavor to give a few points on this subject. That a coke should be a good cupola coke, it is not neces- sary that it sliould in every respect be equal to ConneIls\iIle. A coke that is worthless in a blast furnace producing yco tons of iron a day and kept in blast for many months, or as long as the furnace lining will last, may be a good coke in the cupola mehing a few tons of iron and only in blast for from one to two or three hours. A soft coke, free from impurities detrimentnl to iron, may be more economical than a hard one, even if double the quan- tity is required to do the melting and more time is consumed in melting. Gas-house coke may be used for melting small heats and coke made in the vicinity f*)r other purposes may be used for melting if the cupola is managed to suit the coke, or founders may find it more economical to construct ovens and make their own coke from coal in the immediate vicinity, as did foundry- men years ago, than to pay for transporting the be;ter grades hmg distances. Almost any coke will produce hot iron in a cupola if properly managed. Two things are necessary in the manufacture of a good foundry coke. First, a good coking coal free from sulphur and other impurities detrimental to iron. Second, a properly constructed oven and a knowledge of the process of coking. Foundries located at a long distance from the coke centers, that contem|)late making their own coke with a view of reduc- ing cost in melting, should bear these facts in mind, and have ID 242 THE CUPOLA FURNACE. the available coal analyzed or thoroughly tested by coking in a small way, before going to the expense of constructing an oven or ovens of sufficient capacity to supply their wants. In the early days of melting with coke it was the custom in filling a cupola, after putting in the bed, to mix the iron and fuel by putting in a shovel or two of coke and a few pieces of pig or a few shovels of scrap, and so on, until the entire amount of iron to be melted was placed in the cupola. Cupolas were filled in this way upon the theory or supposi- tion that iron was melted in a cupola all the way up to the charging door, and two or three sets of tuyeres were placed in cupolas, one above the other, that the tuyere pipes might be raised to a higher set of tuyeres and the lower ones closed, when it was desired to collect molten iron for a large casting. This practice was still in vogue in some sections in the early seventies, but had been abandoned long before that time in other sections ; and the practice of placing fuel and iron in charges as at the present time, adopted upon the theory that iron is only melted in a cupola in a given space, which has been designated the melting zone. With the system of mixing the iron and fuel the per cent, of fuel consumed was much larger than with the present system, and the melting slower. When visiting foundries where this system was in use, I have frequently reduced the fuel consumed one-half and the time required for melting an equal amount, by changing the manner of filling the cupola to the charge system. In early days, coke was all measured, bought and sold by the bushel, instead of by weight, and after the adoption of the charge system bushel baskets were used for measuring the coke and placing it in the cupola. A founder when speak- ing of the ratio of fuel to iron melted, would state the amount melted per bushel of coke, in place of to the pounds of coke. The bed and charges of coke were placed in the cupola by measure instead of by weight. To learn the number of bushels of coke required for a bed for a cupola of any given diameter, CUPOLA FUELS. 243 the number of cubic inches in the space to be filled was ascer- tained, and this number divided by the number of cubic inches m a bushel. For example, we will take a 30-inch cupola, with tuyeres 6 inches in diameter located 12 inches above the sand bottom. This would make 18 inches from bottom to top of tuyeres. Add to this 18 inches for bed above top of tuyeres and we have a space or depth to be filled of ^6 inches. The area of 30 inches diameter is 707 ; multiply this by 36 and we find the area to be filled to be 25.452 cubic inches. Divide this num- ber of cubic inches by the number of cubic inches in the average bushel, 2,200, and we find 1 1^ bushels of coke would be required for a bed for this cupola. The charges of coke were generally made 5 inches in thick- ness, and the amount of coke required learned by multiplying 707 by 5 and dividing the product by 2,200, which gives the amount of coke required for each charge, 1.6 bushels. To these bushels were added, from time to time, a sufficient amount to make up for the burning-away of the lining and en- larged diameter of the cupola. The melting qualities of a coke were judged by its weight per bushel. A soft, porous coke weighed 32 pounds and the harder and better the coke the heavier it weighed up to 46 pounds per bushel, which was regarded as the maximum weight of the best coke. The weight of a charge of iron on the bed varied with the quality of coke, and was from an equal weight of the bed to three times its weight. And the amount of 'iron placed in each charge varied from two to ten times the weight of the coke placed in the charge to melt it. The number of pounds of iron melted to pounds of fuel varied with quality of coke and size of heat, and was from 3 to 8 to I. This was the common practice of judging the quality of coke and melting in all the leading foundries in the early sixties. And in many of them there was more system in melt- ing than in one- half the foundries at the present time. In the early days of coke its quality varied to a considerable 2 44 THE CUPOLA FURNACE. extent. This was due to the differences in the coal from which the coke was made, and again to badly designed and poorly constructed ovens and to lack of knowledge of the process of coking. The-e -difficulties have been overcome by the discovery of veins of coal more suitable for coking, the construction of ovens better adapted for the purpose, and a more perfect knowledge of the process of coking. Coke at the present time is of a more uniform grade than years ago, but there is still a considerable difference in the characteristics of the various kinds. This variation is due in some instances to the quality of coal,, but more frequently, especially in coke of the Connellsville region, to the time consumed in coking. This region has pro- duced from time to time 24, 36, 48 and 72-hour coke. These cokes differ in density or hardness, according to the time con- sumed in coking, and vary in weight from 40 .pounds to 72 pounds per bushel, which latter is said to be the weight of the Davis by-product coke. The greater the length of time coke remains (up to a certain period ) in an oven in the process of coking, the denser and harder it becomes. And the harder a coke, the longer time re- quired to consume it in a cupola, the heavier the burden it will carry and the larger the amount of iron it will melt. It therefore follows that a 72 hour coke is the best cupola coke; next to this is the 48 liour coke, and so on down to the 24-hour coke. Seventy- two hour coke for many years, and if we are not mistaken, at the present time, is only made once a week in the Connellsville region. The coke men of this region follow the example of the Lord, as set forth in the Bible, "And on the Seventh day rest from all their labors," and no ovens are drawn on Sunday. The coke in ovens falling due to be drawn on Sunday as 48-hour coke, is permitted to remain in the ovens until M.)nday, when it becomes ; 2-hour coke, and this is the only 7J-hour coke made. It is generally kept for filling CUPOLA FUELS. 245 foundry orders, but the supply is limited, and when exhausted orders are sometimes filled with 48-hour coke instead of 72- hour. This is one of the reasons for the variation in the quality of foundry cokes and the cause of bad workings of cupolas and poor melting, for the different grades of coke require a varia- tion in the charging of a cupola, when coke is charged by weight in place of by measure. The cupola furnace is a space furnace in which iron is melted in direct contact with the fuel, and is supported by the fuel previous to melting. To melt iron in this furnace, a sufficient space must be filled with fuel to admit of the iron to be melted entering the melting zone when the cupola is in blast as rapidly as it can be tnelted. If the amount of fuel is insufficient to fill the cupola to a proper height, the iron placed upon it settles below the melt- ing zone and cannot be melted ; and if the fuel is in excess and fills the cupola above a proper height, iron placed upon it can- not be melted until the excess of fuel is burned away, and per- mits the iron to settle into the melting zone. It is therefore a matter of space occupied or filled by fuel rather than of weight of fuel. With the old rule of placing coke in a cupola by the bushel, all cokes filled the same space, no matter to what extent their weights might differ per bushel. But the same weights of the different cokes do not fill the same space. To illustrate this we will take the cupola above referred to, for which 1 1.56 bushels of coke are required for a bed. This number of bushels of coke of the various weights per bushel gives the following total weights : Coke 32 lbs. per bushel 369 92 Coke 46 lbs. per bushel 53' -76 Coke 60 lbs. per bushel 693.60 Coke 70 lbs. per bushel 809.20 The total weights of any of these cokes would make a bed 240 THE CUPOLA FURNACE. for this cupola, but the same weight of no two of them would make a proper bed. For instance, were we to put in the weight of 11.56 bushels of 32-pound coke, 369.92 of 70-pound coke, this amount would not fill the cupola to the top of tuyeres, and not a pound of iron could be melted with such a bed. On the other hand, were we to put in the weight of 11.56 bushels of 70 pound coke, 809-20 of 32-pound coke, the cupola would be filled to such a height above the tuyeres that not a pound of iron could be melted until 439.28 lbs. of coke was burned away and permitted the iron to settle into the melting zone. The same rule applies to the charges equally as well as to the bed, and when the space between the charges of iron occu- pied by fuel is too small, the bed is not properly replenished, and the result is dull iron after one or more charges have been melted. When the space filled with fuel is in excess, irregular and slow melting results, due to the melting being stopped while the excess of fuel is being burned away to admit of the next charge of iron settling into the melting zone. Melters who do not understand the space theory of a cupola will invariably increase the weight of coke in bed and charges when they have a soft, light coke to melt with, and decrease it when they have a hard, heavy coke. This is a mistake, and exactly the reverse should be done. For the lighter a coke, the more space it occupies, and the heavier a coke, the less space it occupies, as illustrated in the bed of 32-pound and 70 pound coke. And by increasing the weight of coke, or even putting in the same weight with a light coke as a heavy one, too great a space is filled with fuel, and iron is placed too high in a cupola for either fast or economical melting. This theory of melting should be followed by every founder melting with coke, and as the quality of the different cars of coke frequently varies to a considerable extent, some means should be devised or provided in every foundry for determin- CUPOLA FUELS. 247 ing the weight of coke per cubic foot or bushel when such information is not furnished with the coke, and charging should be made to suit the quality of the coke. Hot iron may be melted in a cupola with any grade of coke if this theory of melting is practiced ; and equally hot fluid iron can be melted with a 32-pound as with a 70-pound coke. But it must be remembered that a light coke is inferior to a heavy one as a cupola fuel. It will not carry as heavy a bur- den or melt iron as rapidly, and a cupola cannot be kept in blast in good condition for melting for so great a length of time. And with a very light coke, it is sometimes necessary to make the size of a heat to suit the coke, for even by tapping slag a cupola could not be kept in blast for any great length of time with light gas-works coke, while a cupola may be kept in blast as long as the lining will last with a good quality of coke, and good melting done throughout the heat. The remedy in melting when coke is poor is not to increase the coke, but to decrease the weight of iron on bed and charges, and they should be varied to suit the coke. When a coke is light, and the weight placed in the bed and charges is reduced, the weight of iron placed upon them should be correspondingly reduced ; and when coke is heavy, the weight in bed and charges should be increased and the weight of iron also increased. Coke and iron should be evenly charged throughout a heat, that is, the proportion of fuel to iron should be the same. The old rule of charging is to place three pounds of iron to one of coke in the bed, upon the bed, and ten to one upon the charges. This rule is a good one, as it gives the proportion of fuel to iron throughout a heat, and with 46-pound coke and tuyeres of a certain height gives about the proper proportion of fuel to iron for fast and economical melting. But the rule is not appli- cable in all cases. In the first place, the rule does not apply to cupolas with tuyeres of different heights, for fuel under the tuyeres takes no part in melting, and when tuyeres are very 248 THE CUPOLA FURNACE, high the amount of coke required for a bed is so large that three to one cannot be melted upon it without lowering ihe top of the bed to such an ext«. nt that it is not restored to a proper height for milling by the next charge of fuel. The result is uneven melting and dull iron throughout the remainder of the heat. With low tuyeres the weight of coke required for a bed is not so great, and four or five to one may be melted upon it with the same grade of coke without detriment to further melting. Again, the rule does not apply accurately to coke of difTerent grades; for we have found in a number of case>, when meltirg vi^ith gas-wcuks coke, that from one to two to one was the best that could be done on the bed, and from five to six to one the be'-t that could be done on the charges ; and in tlie same cupola we have melted four to one on the bed and ten to one on the charges wiih a good coke. In regulating melting in dififerent foundries we have found our best guide for bed and charges to be measurement and weight, as follows : When melting in a cupola we had never seen melt, and for which previous melting was no guide for melting, we first ob- tained the measurement from sand bottom to top of tuyeres, then measurement from bottom of charging door down to a proper height for top of bed, and procured a pole or rod for determining this measurement when the bed was in. We then determined the quality of coke by weighing a bushel, or by in- spection. The blast machinery and pipes were then inspected and a bed put in to suit the coke and blast. With a light coke the bed was made a iittle higher than with a heavy one. And with a strong blast it was made higher than with a light blast, the height of bed generally being from 18 to 20 inches above top of tuyeres. When the tuyeres were very high, 18 to 20 inches above sand bottom, and the coke light, one to two pounds of iron were placed upon the bed to every pound of coke in the bed. CUPOLA FUELS. • 249 And with a heavy coke two to three to one were placed on the bed. With low tuyeres, four to eight inches above sand bottom, and light coki, two to three to one; heavy coke, three to four to one. The top of bed and also charges of fuel and iron were made as level as possible before putting in the next charge. For charges of coke, a sufficient quantity was put in to properly cover the iron (about five or six inches), and separate charges of iron. On the charges of coke were placed from three to five of iron to one wiih a light coke, and eight to ten to one with a heavy coke. This means of determining the proper amount of fuel for bed and charges and ratio of iron on fuel, in bed and charges, sel- dom failed to produce satisfactory melting, which might or might not be improved. To determine this the melting was watched from the time the bhist was put on until the bottom was dropped for indica- tions of necessary changes. All coke and iron was accurately weighed, the front put in and tuyeres closed as soon as bed was properly burned for charging, and charging began fiom two to three hours before blast was put on. If iron ftiiled to appear at the tap hole in five minutes after the blast was on, the bed was too high, and for the next heat was reduced a little. If iron came dull at the latter end of charges, charges of iron were too heavy and were reduced next heat. If the cupola did not melt rapidly the charges of fuel were too heavy. If iron was not of an even temperature through- out a ht at charges of fuel and iron were not of a proper pro- portion. All these things were noticed and changes made in the charging until the cupola melted the largest stream of iron it was capable of mehing suitable for the work to be cast, and an even temperature throughout a heat. When this had been acconiplished, the most economical 250 THE CUPOLA FURNACE. melting that could be done in that cupola with the grade of coke used was being done, and it did not matter whether two to one or ten to one was being melted, the per cent, of fuel to iron could not be reduced. The question of per cent, of coke to iron or of the number of pounds of iron that can be melted to the pound of Connells- ville coke is a matter upon which there appears to be a wide difTerence of opinion, and upon which few are capable or will- ing to give definite practical information. Periodically there appears in the scientific and mechanical papers a good cupola record, in which the writer claims to have melted anywhere from 10 to 15 to one. In Mr. West's work, " The Holder's Text Book," we find re- ports of melting with Connellsville coke from 24 foundries, in which the per cent, of fuel to iron of no two of them is the same and the ratio of fuel varies from StVo to i 1y\ to one. In these reports the size of heats varies to a considerable ex- tent, but the largest heats do not always show the lowest per cent, of fuel to iron, and we find heats of 8,000, 10 to one; 41,000, 7.84 to one; 21,000, 5.91 to one; 3,500. 6.64 to one; and in very few of them do the largest heats show the best per cent, of iron to fuel, which would seem to indicate that the old theory, that the larger the heat the smaller the per cent, of fuel, was all wrong. These reports indicate that the management of cupolas is very poorly understood by the majority of the foundrymen making them, or that others through a desire to excel have misrepresented their meltings ; and we are inclined to believe the latter to be the case, for in all our experience in melting we have never seen any such melting done as reported by some of them ; nor have we ever niet a practical founder who made such extravagant claims. Few practical founders claim to melt more than eight to one in their largest heats, and the majority of them do not state their average melting to be more than seven to one, and many place it even lower with the best of coke. CUPOLA FUELS. 25 I As stated above, the best and only guide the founder has to economy in fuel is fast melting and iron of a temperature suit- able for work to be cast; and when he melts his iron as fast as a cupola is capable of melting and of a temperature at the spout suitable for the work, he is doing all that can be done to save fuel, and no attention should be given to extravagant cupola reports made by other foundries. BY-PRODUCT COKE. Within the past few years a marked advance has been made in the manufacture of by-product coke, and it has taken its place as a cupola fuel to the extent of excluding Connellsville and other cokes in many localities. At Syracuse and Roches- ter, N. Y., what is known as the Solvay coke made at the Sol- vay plant, Syracuse, N. Y., is about the only coke used for melting in the foundries of these cities. This company also have works at Milwaukee, Wisconsin, which supplies a very large per cent, of the cupola coke used in that city, and also at Chicago and other places where their coke is in great demand. The Illinois Steel Co., Joliet, 111., and other large plants in the west have erected by-product coke plants for making their own coke from western coal, and it would appear to be only a question of a very few years when the West will be making all their own foundry coke from western coal. Owing to the large per cent, of sulphur this coal contains, it was not thought pos- sible, a few years ago, to make a good foundry coke from it, but a new process has been found that so thoroughly eliminates this element from the coke, that it is said to be more free from it than many of the Connellsville cokes. By-product coke is darker in color, is not produced in so large pieces, and has not the luster or ring of Connellsville coke, but it is said to possess an equal number of heat-produc- ing units, and in cupola practice gives equally as hot and fluid an iron. There appears to be considerable difiference in the density of by-product coke made by dififerent processes, and some carry 2 52 THE CUrOLA FURNACE. a much heavier burden in melting than others. For this reason charges of iron have sometimes to be. made lighter than with ConntlLsville coke. But with the Solvay coke charges are made about the same and results in n)elting per pound of coke are about the same, although in some cases it is claimed better re.'^uhs have been obtained by the use of it than with Connells- ville. BITUMINOUS COAL AS A CUP. )LA FUEL. Between the period of the discovery of bituminous coal in this country and the introduction of the process of coking, there should have been, and no doubt was, a period when this coal was employed as a cujiola fuel by some of the many small foundries located in the vicinity of these mines. But there appears to have been no record kept of this coal as a cupola fuel by any of the foundrymen of those da)'S, or nothing published in regaid to it ever having been used for this purpose. That there should be no such records is not strange, for nothing can be found upon the subject of any of the other cupola iucU, or mode of using them, piior to my work, "The Founding of Metals" (1877). Nor does there appear to have been anything published upon this subject, in England or other countries prior to that date. Twenty-five years ago I made inquiry among foundrymen and molders in different parts of the country as to the use of various cupola fuels in their early days. Many of them re- membered melting with charcoal before the introduction of anthracite coal and coke in their locality, but only three, my notes show, remembered melting with bituminous coal. Two of these were located in Western Pennsylvania and one in Ohio when melting was done with this coal without coking, but none of them had kept any record of the melting and were unable to give any practical data in regard to melting with it. My own experience in melting with this fuel in a cupola has been limited to one cupola, that of Joseph King & Co., Sharon, Pa. This firm received their supply of cupola coke at that time CUFOLA FUELS. • 253 from Pittsburg, Pa., by boat, on the Erie and Pittsburg Canal ; and it was their custom to l.iy in a sufficient supply in the fall to last until the canal opened in the sprinfjj. In the winter of 1865 and 1866 their supply ran short, and they were compelled to pay the high rate of a railroad that had just been opened the year before, look for other fuel, or shut down until the canal opened. At that time the Sharon Iron Co. were using a very hard bituminous coal in their bl.ist furnace without coking, and the foundry company were induced to try this coal in their cupolas. The first heat with it was not a success. The iron melted hot and dull, fast and slow, and the greater part of it was so dull it had to be poured in the pig bed. But part of it, in different parts of the heat, was sufKiciently hot and fluid to run light v\ork. This indicated that the fuel would do the melting, but the cupola had not been properly charged. For the next few heats the charges of fuel and iron were varied with better results, and in the third or fourth heats iron was melted sufficiently hot and fluid to run stove-plate and light jt/bbing work; and melting was done with this coal for a number of weeks, until the canal opened and they received a supply of coke. This melting was done in a 28-inch cupola. A bed was put in of the same height above the tuyeres, and the charges of coal made of same weight as when melting with coke. But the charijes of iron on the bed and those on the charges of fuel were made hghter, and the ratio of iron to fuel reduced from 7 to i with coke to 5 to I with coal. This is as good a per cent, of fuel to iron as the majority of founders melting small heats in small cupolas obtain with the best of coke. The quality of iron was not deteriorated by the coal, and it was not found necessary to make any change in the mixture to obtain as good a quality of iron in the castings as when melt- ing with Pittsburg coke. The coal used in this instance was very hard bituminous coal^ 2 54 THE CUPOLA FURNACE. and was said to be the only coal mined in this section that could be used in a blast furnace without coking, which was probably the case, for when the mine became exhausted the furnace began using coke as a fuel. All bituminous coals are not available as a cupola fuel. Some are too soft, fuse into a solid mass, or burn away too rapidly when subjected to a strong blast, and others contain so large an amount of sulphur that they harden the iron and render it brittle. In selecting a coal, a hard coal free from sulphur should be chosen. When such a coal is not obtainable, small heats may be melted with a soft coal and a light blast, and sulphurous coals may be used for some lines of work by charging a better grade of iron than when melting with a fuel free from sulphur. There are some sections of this country in which very hard bituminous coal is mined, that can no doubt be employed as a cupola fuel by small jobbing foundries located in districts where other fuels are very expensive. A WONDERFUL CUPOLA. Herbert M. Ramp, Springfield, Mo., writes on this subject to the "American Machinist," as follows: " Under the above heading an article appeared in the 'American Machinist,' September 27th, showing a cupola sup- posed to be doing phenomenal work, but upon a careful con- sideration and comparison with other cupolas on the same basis a great deal of the wonderful disappears. The economy is not as great as supposed at a casual reading. " In the first place the ratio of fuel to iron is given on the basis of what is used between charges, leaving the bed out en- tirely, neglecting the fact that the bed is a most important factor in raising the temperature of the cupola and all it contains. At the same time the first charge of iron is melted on the bed, and is clear gain in ratio of fuel on this basis. No charge being made against it, a considerable alteration is made in the pio- portion, especially if the heats only run from one to two hours. CUPOLA FUELS. 255 " From my own experience I can assert that, based on the preceding basis, I have accomplished an equal result with that shown by Mr. Bollinckx. " The past month I have used a cupola built on the plan shown in the ' American Machinist,' September 20th, 30 inches in diameter clear of the brick. Aside from the bed I have used fuel at the rate of i to 20, taking the coke and iron relative in each charge, but upon the addition of the charge melted on the bed the ratio will run up to i to 22 and i to 23 ; but taking the same heats and adding in the fuel used on the bed the ratio is brought down to the more rational figures of i to 14. " I can safely say I have not reached the limit of this cupola, but my experiments have been delayed on account of several cars of poor coke. I had not intended to write of this cupola at present, and later on will present a paper on it, but American pride bade me proclaim what is done in our country when its reputation for excellence is at stake. The iron used was from 30 to 50 per cent, pig iron, and the remainder heavy railroad scrap. " The cupola melts from 4)^ to 5 tons per hour. I make no claims as to the economy of the cupola, but rather to the management. "As in the case of the Greiner, there is no flame shown at the chargmg door, and very little gas or smoke, the tempera- ture at that point not running over 125° Fahr., but this is not due to the construction of the same, but the manner af charg- ing, and any cupola can be handled so that it has from 9 to 1 1 feet height to the charging door. "Any further information desired on this subject I will cheerfully give if in my power through the columns of the 'American Machinist' or by personal letter." The above is a fair sample of a wonderful cupola or melting record, that appears periodically in the mechanical and foundry publications of this country, and evidently from the reading of the above, they also appear in similar publications of other countries. 2S6 THIC CUPOLA FURNACE. Can it be possible, that all the many cupola designers, cnpola experts, and cupola scientists of this country and Europe, have overlooked an important point, in simply charging of the cupola, and have been for years using from 50 to 60 per cent, more fuel than necessary to melt their iron? This would ap- pear to be the case, for Mr, Ramp claims to have done this rr.elting in an ordinary 30-inch cupola. Is it at all likely that all the manufacturers of standard cupolas, one of whom prob- ably made the one used by Mr. Ramp, have been underesti- mating the fuel ratio required in their cupolas 40 to 50 per cent.? Can it be that the thousands of foundrymen of this country and Europe have for years been using from 50 to 60 per cent, more fuel than is actually necessary to melt their iron? It is not at all likely that all these practical and scientific men have made such a gross mistake in the estimating of fuel re- quired and manipulation of their cupola. Nor is it at all likely that Mr. Ramp melted 22 to 23 to i without counting the bed, and 14 to I counting the bed, anywhere but in his mind. For it is not pos-^ible to melt a five-ton heat in a 30- inch cupola with any such per cent, of fuel, let alone melting four and a half to five tons per hour. Mr. Ramp does not appear from the above statement of melting to understand the first principles of a cupola or to realize that it is a space furnace in which iron can only be melted within a given space, known as the melting zone. And iron must be sui'ported in this zone by the melting fuel imtil melted. Should it sink below this zone, after being converted into a semi fluid mass, it is struck by the blast, and conceited into slag by its bessemerizing action, and meliing at once stops. Should it descend to this point in a solid state, it is struck by the cold blast, and rapidly cooled. To support iron in a cupola, at the top of the melting zone, a bed of fuel is put in, that will fill the cupola to this point. Upon this bed a charge of iron is placed that may be melted while the fuel is burning away and settling to the lower edge of the zone or melting space. On the top of this iron a charge of fuel is placed of CUPOLA FUELS. 257 sufficient depth or thickness to bring the top of the bed again up to the top of the melting zone. This fuel melts the next charge of iron, and so on through the heat. An excess of fuel in the bed or charges causes slow melting. And a deficiency of fuel causes dull iron and melting may stop entirely. The rule for charging is to place ten pounds of iron to one of fuel in the charges, when iron is not required to be very hot and fluid, and toward the end of a heat twelve to one may be charged. Mr. Ramp must have a bed of this height and he does not appear to make any extravagant claim for saving fuel in the bed. For without counting the bed, he claims to have melted 22 to 23 to I. Now by what hocuspocus can he make a pound of coke melt 22 to 23 pounds of iron in his charges, while others can only melt 10 to 12 in cupolas of the same design and construction? He must either charm the fuel or the blast to obtain such results. Practical foundrymen pay no attention to any such articles that they may see in print, but all foundrymen are not practical foundrymen, and the reading of such stufT makes them think they are not getting the best of results in melting, and the fore- man is not a competent man for the position he holds, thus placing him under a cloud, and creating dissatisfaction, which may result in a vacancy for a foreman, which would seem to be the object of the writer of such articles. But there is a larger field for Mr. Ramp as an expert melter than as a foundry fore- man, for every founder would like to save 50 per cent, of his cupola fuel, and no doubt would be willing to pay liberally for points in melting that would enable him to do so. 17 CHAPTER XIII. FLUXING OF IRON IN CUPOLAS. Flux is the term applied to a substance which imparts igneous fluidity to metals when in a molten state, and has the power to separate metals contained in metallic ores from the non-metallic substances with which they are found in com- bination ; also to separate from metals when in a fluid state any impurities they may contain. Fluxes are also used for the pur- pose of making a fluid slag in furnaces to absorb the non- metallic residue from metals or ores and ash of the fuel, and removing them from the furnace to prevent clogging and to keep the furnace in good working order for a greater length of time. The materials used as fluxes for the various metals are numerous and varied in nature and composition, but we shall only consider those employed in the production of iron and the melting of iron for foundry work. The substances employed for this purpose are numerous, but they consist chiefly of the carbonate of lime in its various forms, the principal one of which is limestone. In the production of pig iron from iron ore in the blast fur- nace, limestone is used for the two-fold purpose of separating the iron from the ore, and for liquefying and absorbing the non-metallic residuum of the ore and ash of the fuel, and carry- ing them out of the furnace. For this purpose large quantities of limestone are put into the furnace with the fuel and ore. The stone melts and produces a fluid slag, which absorbs the non- metalHc residuum of the ore and ash of the fuel in its descent to the bottom of the furnace. Thence it is drawn out at the slag hole, and carries with it all those non-metallic substances which tend to clog and choke up the furnace. By this process of fluxing the furnace is kept in good smelting order for ( 258 ) FLUXING OF IRON IN CUPOLAS. 259 months, and even years. Were it not for the free use of lime- stone, the furnace would clog up in a few days. The blast furnace is a cupola furnace, and is constructed upon the same general principle as the foundry cupola. Foundry men long ago conceived the idea of using limestone as a cupola flux. In many foundries it is the practice to use a few shovel- fuls or a few riddlefuls of finely broken limestone in the cupola on the last charge of iron, or distributed throughout the heat, a few handfuls to each charge of iron. The object in using lime- stone in this way is not to produce a slag to be drawn from the cupola, but to make a clean dump and a brittle slag or cinder in the cupola, that can be easily broken down and chipped from the lining when making up the cupola for a heat. Limestone used in this way does not produce a sufficient quantity of slag to absorb the dirt from the iron and ash of the fuel and keep the cupola open and working free, but rather tends to cause bridging and reduce the melting capacity of the cupola. The making of a brittle cinder in a cupola by the use of lime- stone depends to a great extent upon the quality of the stone. Some limestones have a great afiFinity for iron and combine with it freely when in a molten state, while others have but little affinity for iron and do not enter into combination with it at all. In the cinder piles about blast furnaces we find cinder almost as heavy and hard to break as iron, resisting the action of the atmosphere for years; while at others we find a brittle cinder that crumbles to pieces after a short exposure to the atmos- phere, or even slacks down like quicklime when wet with water. In a cupola we may have a hard or brittle cinder produced by limestone. The results obtained from the use of limestone in small quantities in a cupola are so uncertain that we do not think they justify the foundryman in using it. LIMESTONE IN LARGE QUANTITIES. The tendency of slag or cinder in a cupola is to chill and adhere to the lining just over the tuyeres and around the cupola 26o THE CUPOLA FURNACE. at this point, and prevent the proper working of the furnace. So great is this tendency to bridge that a small cupola will not melt properly for more than two hours, and a large one for more than three hours. To overcome this tendency to clog and bridge, foundrymen in many cases have adopted the bla'^t- furnace plan of using a large per cent, of limestone as a flux in their cupolas, and tapping slag. When a large per cent, of limestone is charged with the iron in a cupola, it melts when it settles to the melting point and forms a fluid slag. This slag settles through the stock to the bottom, and in its descent melts and absorbs the ash of the fuel and dirt or sand from the iron and carries them to the bottom of the cupola, where the slag and dirt it contains may be drawn ofT and the cupola kept in good melting order and in blast for days at a time. The amount of limestone required per ton of iron to produce a fluid slag depends upon the quality of the stone and the condition of the iron to be melted. It is the custom in some foundries, where the sprevvs and gates amount to from thirty to forty per cent, of the heat, to melt them with- out milling to remove the sand, and to use enough limestone in the cupola to produce a sufficient quantity of slag to absorb and carry out of the cupola the sand adhering to them. In this case a larger per cent, of limestone is required than would be necessary if the sprews and gates were milled and only clean iron melted. Poor fuel also requires a greater amount of slag to absorb the ash than good fuel, and a lean limestone must be used in larger quantities than a stone rich in lime. The quan- tity required to produce a fluid slag, therefore, varies with the quality of the limestone and the conditions under which it is used, and amounts to from 25 to lOO pounds per ton of iron melted. The weight of the slag drawn from a cupola when the sprews and gates are not milled, and the cupola is kept in blast for a number of hours, is about one- third greater than the weight of the limestone used. When the sprews and gates are milled, the weight of the slag is about equal to the weight of the lime- FLUXING OF IRON IN CUPOLAS. 261 stone. When the cupola is only run for a short time and slag only drawn during the latter part of the heat, the weight of the slag is less than the weight of the limestone. The slag drawn from a cupola has been found by chemical analysis to contain from 4 to 7 per cent, of combined iron and numerous small particles of shot iron mechanically locked up in the slag. These cannot be recovered except at a greater cost than the value of the metal. In a number of tests made in the same cupola, w^e found the loss of iron to be from 3 to 4 per cent, greater when the cupola was slagged. EFFECT OF FLUX UPON IRON. Many of the limestones and other mineral substances em- ployed as cupola fluxes contain more or less finely divided oxides, silicates, etc., in combination with earthy materials. The flux is often reduced in a cupola and its component parts separated, and in minute quantities they alloy with the iron and injure its quality. The combined efifect upon iron of these diffused oxides, silicates, etc., liberated in a cupola from their native element in fluxes, is to prevent the metal running clean in the mold or making sharp, sound castings, and the tensile and transverse strengths are frequently impaired by them. When the oxides, silicates, etc., are not separated in the cupola from their native elements, they do not impair the quality of the metal, nor do they improve it. The tendency of the cupola furnace is to clog and bridge over the tuyeres, and concentrate the blast upon the iron through a small opening in the center and injure its quality. If by the free use of limestone we pre- vent bridging and keep the furnace working open and free, we avoid injuring the iron in melting by the concentration of a strong blast upon it. The etTect, therefore, of limestone in a cupola is not to improve the quality of iron, but to prevent its deterioration in melting. THE ACTION OF FLUXES ON LINING. Limestone and other minerals employed as fluxes frequently 262 THE CUPOLA FURNACE. contain impurities which enter into combination with the h'ning material of a furnace and render it fusible. This was illustrated at the foundry of John D. Johnson & C6., Hainesport, N, J., in 1893. The cupola front had been put in with new molding sand for a long time, and no fllux used in the cupola. The sand made an excellent front that resisted the action of the heat and molten iron upon it. As the heats enlarged, it became neces- sary to use flux and tap slag to run off the heat. Oyster shells were used, and produced a slag that flowed freely and had no effect upon the sand in the front. When the supply of shells became exhausted, a limestone was used in place of them. Trouble then began with the front. It was melted by the flux into a thick, tough slag that settled down and closed up the tap hole, and iron could only be drawn by cutting away a large portion of the front to enlarge the tap hole. Mr. Johnson called at our office to learn what could be done to keep the tap hole open. We advised that the front material be changed and a mixture of fire-clay and sharp sand be used in place of mold- ing sand. This was done, and there was no further trouble in keeping the tap-hole open and in good order to run ofT the heat. This serves to illustrate the efifect of fluxes upon lining material. With no flux and with oyster shells the molding sand resisted the heat and pressure of molten iron and slag upon the front; but with limestone it melted into a thick, tough slag. This was due to some property in the limestone entering into combination with the sand and making it fusible. Had the cupola been lined with this molding sand, the entire lining would have been cut out in one heat, while it would have stood many heats with shells or no flux at all. From the various qualities of cupola brick and lining material now in the market, a lining may be selected that will resist the action of almost any flux or slag, and foundrymen may select a flux to suit the lining or a lining to suit the flux, whichever they find to be the most profitable in their locality. FLUXING OF IRON IN CUPOLAS. 263 HOW TO SLAG A CUPOLA. Foundrymen sometimes experience trouble in slagging their cupolas. This is largely due to a lack of knowledge in charg- ing the limestone and drawing the slag, for any cupola can be slagged if properly worked. To draw slag from a cupola, a sufficient quantity of limestone or other slag-producing material must be charged in the cupola with the iron to make a fluid slag. The exact amount required can only be learned by ex- perimenting with the fluxing material used, but it is generally from fifty to sixty pounds of good limestone per ton of iron, when the remelt is not milled. The limestone is generally charged on top of the iron and put in with each charge after the melter begins using it. No limestone is used with the iron on the bed or first few charges of iron. In small cupolas lime- stone is generally charged with the second or third charge of iron. In large cupolas, when the charges of iron are light, six or eight charges, or generally about one-sixth of the heat, are charged without limestone. This is the way limestone is used when the cupola is run in the ordinary way for a few hours. When the cupola is run for some special work, the limestone is charged in a number of dififerent ways. The slag is drawn from the cupola through an opening known as the slag-hole. This opening is made through the casing and lining under the low er level of the tuyeres and at a point in the cupola where it will be out of the way in removing iron from the spout and convenient for removing the slag. The height the slag-hole is placed above the sand bottom depends upon how the iron is drawn from the cupola. When it is desired to hold iron in a cupola until a sufficient quantity is melted to fill a large ladle, the slag-hole is placed high, and when the iron is drawn as fast as melted the slag hole is placed low. When the slag hole is placed high, slag can only be drawn as the cupola fills up with iron and raises it to the slag-hole. When the iron is withdrawn from the cupola, the slag falls and the slag-hole is closed with a bod to prevent the escape of blast. When the iron is drawn from the cupola as fast as melted, the slag-hole is 264 THE CUPOLA FURNACE. placed low, and when opened it is permitteil to remain open through the remainder of the heat. This is the best way of drawing slag from the cupola, for the flow is regulated by the amount of slag in the cupola, and if the hole is not made too large, there is no escape of blast. The slag in the bottom of a cupola takes up impurities from the fuel and iron, and if permitted to remain in the cupola for too long a time, it may become so thick and mucky it will not flow from the slag hole. Or it may be filled with impurities, become over- heated, boil up and till the tuyeres with slag ; and when boiling, it will not flow from the cupola through a small slag hole. The time for drawing the slag from a cupola is therefore a matter of great importance. The slag hole is gen- erally opened in from half an hour to an hour after the cupola begins to melt, and when placed low is permitted to remain open throughout the remainder of the heat. When placed so high that slag can only be drawn when the cupola fills up with molten iron, it should be opened as soon as the slag begins to rise and closed as soon as it falls below the opening. DOES ir PAY TO SLAG A CUPOLA ? Nothing is gained by slagging a cupola when the sprews and gates are milled and the heat can be melted successfully in the cupola without slagging; but a great saving in labor and wear and tear of machinery can be efifected in many foundries by melting the sprews and gates with the sand on, and slagging to carry the sand out and keep the cupola working free. A cupola cannot be made to melt iron faster by slagging, but it can be kept in blast and in good melting condition for a greater length of time and a much larger amount of iron melted by slagging. Foundrymen who find their cupolas temporarily too small to melt the quantity of iron required for their work, can overcome the difficulty by slagging the cupola and keeping it in blast for a greater length of time. In endeavoring to make an estimate of the cost of slagging a cupola, we found that the cost of limestone in different localities FLUXING OF IRON IN CUPOLAS. 265 varied from 50 cents to $3 per ton. The amount used varied from 25 to 100 pounds per ton of iron melted. The amount of slag drawn varied from 25 to 100 pounds per ton of iron. The iron combined with the slag varied from 4 to 7 per cent. With these wide differences in the cost and quantity of limestone used, and the difference in the quantity of slag drawn and per cent, of iron it contained, we found it impossible to make an estimate that would be of any practical value to foundrymen. Such an estimate must be made at each foundry to be of value. * SHELLS. Oyster, clam and other shells are largely composed of lime, and are frequently used as a flux in place of limestone in local- ities where they can be procured at a less cost than the latter. The shells are charged in the same way as limestone and in about the same proportion to the iron. They may be used in place of limestone either in large or small quantities, and have about the same efifect upon the iron and cupola as limestone. When used in large quantities, they produce a fluid slag that keeps the cupola working free and flows freely from the slag- hole, carrying with it the refuse of melting that clogs the cupola. When the heat first strikes shells in a cupola, they produce a crackling noise and flakes of shell may be seen to pass up the stack, and the foundry roof, when flat, is often covered with flakes of shell after a heat, when they are used in large quantities. The crackling is due to the destruction of the hard inner surface of the shell; the flakes thrown from the cupola are entirely of this surface, and the loss of shell is not so great as it would appear to be at first sight. The remainder of the shell melts and forms a fluid slag that absorbs the refuse of melting, becomes thick and helps to clog up a cupola when the shells are used in small quantities, or assists in keeping it open when used in large quantities. MARBLE SPALLS. Marble is another of the carbonates of lime, and the spalls or 266 THE CUPOLA FURNACE. chippings from marble quarries or works are quite extensively used in some localities as a cupola flux. Their action in a cupola and their effect upon iron is very similar to that of lime- stone, and they are used in the same way and in about the same proportions. There are a number of other substances, such as fluor-spar, feld-spar, quartz-rock and a number of chemical compounds that are used as cupola fluxes. In 1873, when engaged in the manufacture of malleable iron, we began experimenting with mineral and chemical materials with the view of making a cheap malleable iron, and changing the nature of iron in a cupola furnace so that it might be an- nealed at a less cost, and produce stronger iron. In this we succeeded to some extent, and then drifted off into improving the quality of iron in a cupola for grey iron castings; this we have followed for nearly twenty years. During this time we have melted iron in foundries all over the greater part of the United States and Canada, and have constructed and worked a number of experimental cupolas of our own, to learn the effect of different mineral and chemical substances upon iron and cupola linings. In these investigations we have used all the mineral and chemical fluxes known to metallurgical science, and observed their effect upon the various grades of iron employed for foundry work. In these experiments it was found that iron can be improved or injured when melted in a cupola furnace, and is often ruined as a foundry iron by improper melting and fluxing. The point at which iron is melted in a cupola has a great deal to do with its quality. Iron melted too high in a cupola is burned and hardened ; melted too low, it runs dirty in a mold ; melted with too strong a blast, it is hardened. Iron melted dull does not make a sound casting. Iron melted with poor coal or coke is injured by the impurities in the fuel. Iron melted with oyster shells, limestone and other mineral fluxes may take up oxides, sulphides, phosphides, silicates and other impurities contained in the flux and may be ruined by them for foundry work. The per cent, of iron lost in melting is increased by improper FLUXING OF IRON IN CUPOLAS. 267 melting and fluxing, and may be double or treble what it should be. We have made a great many experiments to ascertain the effect of silicon on iron, and have found that silicon enters freely into combination with cast iron and has a softening effect upon it. Iron as hard as tempered steel may be made as soft as lead by combining it with silicon. But silicon is an impurity hav- ing a deleterious effect upon iron. An excess of it destroys cohesive force and crystallization, and reduces transverse and tensile strength. So great is the destruction of cohesive force in cast iron by silicon that the strongest iron may be reduced to a powder when combined with an excess of silicon, Silicon in any proportion is a detriment to cast iron, as an iron. The nature and form of crystallization of a pure cast iron is changed by sudden cooling in a mold, and a soft iron in the pig may become a hard iron in a casting. This chilling property in cast iron is destroyed by silicon, and an iron high in it is not hardened when run into a sand mold or upon an iron chill. The destruction of the chilling tendency in cast iron is very de- sirable in the manufacture of light castings, and for this reason silicon irons are largely used in foundries making this class of work. The per cent, of silicon an iron may contain and yet retain sufficient cohesive force for the work, depends upon the amount of other impurities in the iron and the work the iron is em- ployed to make. For heavy work, requiring great strength, it should contain none at all, For light machinery it may con- tain from one-half to one per cent ; and for stove plate, light bench work, etc., it may contain from two to three per cent. These amounts arc sufficient to reduce the chilling tendency of the iron, without impairing its strength to any great extent in these classes of work. But a larger amount destroys the strength of the iron and also injures its flowing property in a mold. At the present time there is a large amount of high-silicon cheap Southern iron being used in stove foundries for the pur- pose of making a cheap mixture and a soft casting. At one of 268 THE CUPOLA FURNACE, these foundries we recently visited, the foreman informed us that they were using a mixture that cost $14 per ton, and said their breakage in the tumbling barrels and mounting shop was very large, and he never made a shipment to their warehouse in New York, a distance of 25 miles, but a lot of stoves were broken in transit and sent back to be remounted and repaired. At another stove foundry in Troy, N. Y., they informed us they were using a mixture of Pennsylvania irons that cost them $20 per ton. They had scarcely any breakage at their works, and shipped their lightest stoves and plate to their warehouse in Chicago without boxing or crating, and never had any break- age in transit or in handling. They had found by experience that a mixture of Pennsylvania irons at a cost of $20 per ton was cheaper in the long run than a mixture of cheap Southern irons at $14 per ton. In a number of other foundries we visited they all complained of heavy breakage when using high silicon irons as softeners. Another matter to be considered in using these high silicon irons for stove plate is, how long will a stove last made of such weak iron, and can a reputation for good work be maintained by foundries using them? A stove made of this kind of iron will certainly not last so long as one made of good iron. Carbon has the same effect upon cast iron as silicon in soften- ing and reducing the chilling tendency. The hardest of cast iron can be made the softest by the addition of carbon, without destroying its cohesive force and rendering it brittle or rotten, and carbon can be added to iron in a cupola as readily as sili- con. Before the high-silicon Southern irons were put upon the Northern market highly carbonized irons were used as softeners for stove plate and other light work, and a far better grade of castings was made then than now is made from the silicon irons. It is difificult to remove silicon from iron when melted in a cupola, but free carbon is readily removed by the oxidizing flame produced by a strong and large volume of blast; and a soft iron may be hardened in melting to such an extent as to FLUXING OF IRON IN CUPOLAS. 26y make it unfit for the work. This can be prevented to some extent by using a mild blast and melting the iron low in the cupola, and it can also be prevented by the use of chemicals to produce a carbonizing flame. We have spent a great deal of time and money in experiment- ing on the production of such a flame in a cupola as would not only prevent the deterioration of iron in melling, but would improve its quality, and at the present time are engaged in the manufacture of a chemical compound for this purpose. FLUOR SPAR. Fluor spar is extensively used as a cupola flux, in sections of the country where it is found native and can be procured at a moderate cost, and it has also been used to a considerable extent in other sections of the country, but the expense of transporting this heavy material has greatly retarded its use as a flux at any great distance from the mines. Fluor spar when used in sufficient quantities in a cupola produces a very fluid slag that absorbs and liquefies the non-metallic residue of melt- ing with which it comes in contact, keeps the cupola open and working freely, and causes it to dump clean. But it also fluxes the cupola lining, causing it to burn out in a very short time, and for this reason it can only be used in large quantities with certain grades of lining material that are only affected to a very limited extent by it. This quality of lining material can gen- erally be procured in the vicinity of the mine, but it cannot always be had at a moderate cost in other parts of the country, and for this reason fluor spar is frequently used with limestone to increase the fluxing properties of the latter and reduce its own injurious effect upon the cupola lining. When used in this way fluor spar greatly increases the efficiency of a poor limestone, and often enables a founder to use a cheap limestone that could not be employed alone as a flux, while the limestone reduces the injurious effect of the spar upon the lin- ing, and the two combined make an excellent flux for tapping slag in long heats. 270 THE CUPOLA FURNACE. We have used fluor spar in a number of cupolas and with a great many difterent brands of iron. We never found it to harden or soften any of these irons to a noticeable extent, but it improved the melting very materially in a number of cases where the cupola was run beyond its melting capacity, melted slow in the latter part of the heat, and could not be dumped without a great deal of labor. CLEANING IRON BY BOILING. Before the use of fluxes in cupolas was so well understood as at the present time, it was a common practice in many foundries to cleanse iron of impurities in a ladle by agitating or boiling the molten metal. This caused a large amount of dross to collect on the surface, from which it was skimmed ofif and the iron was considered to be purer after the boiling. A favorite way of agitating iron in a ladle was to place a raw potato or apple on the end of a tap bar and hold it in the molten metal, near the bottom of the ladle, for a short time. The potato or apple contained a sufficient amount of moisture to agitate or boil the metal gently without exploding it, and the metal was said to be greatly benefited by this gentle boil- ing; but practice has demonstrated that nothing is gained by boiling iron in a ladle, and it lias long been discontinued in this country. A ball of damp clay placed upon the end of a tap bar was also used for boiling iron in a ladle, but this was not considered so good or so safe as an apple or potato, for if the clay chanced to be too damp, it caused the iron to boil violently and some- times to explode. Another favorite way of cleansing and mixing irons years ago was to pole the molten iron. This was done with a pole two or three inches in diameter, of green hickory or other hard wood. The pole was thrust into the molten metal in a ladle or reverberatory furnace, and the metal stirred with it. The effect of the green wood thrust into the metal was to cause it to boil around the pole, and as the pole was moved through the metal FLUXING OF IRON IN CUPOLAS, 2/1 all parts of it were agitated, and a better mixture of the different grades of iron melted was effected and a moie homo- geneous casting produced. The poling of iron was a common practice in many foundries twenty-five years ago, but we have not seen it done in a ladle for many years, and we believe the practice has been entirely discontinued with cupola-melted iron ; but poling is still practiced in many foundries in the mix- ing of iron in reverberatory furnaces for rolls and other cast- ings requiring a very strong homogeneous iron. CHAPTER XIV. WHAT A CUPOLA WILL MELT. The cupola furnace was originally designed for melting cast iron for foundry castings, and at the present time is principally employed for that purpose, but it is now also used in the melt- ing of almost all of the various grades of manufactured iron and steel, and many other metals. It is extensively employed in the melting of pig iron, in the manufacture of Bessemer steel, and in the melting of iron for castings to be converted into steel and malleable castings after they are cast. It is also used in melting steel for steel cast- ings, but as it makes an uncertain grade of steel it is only em- ployed for the more common kinds of castings. It is also employed in melting tin-plate scrap, sheet iron, wrought iron and steel wire, gas-pipe, bar iron, horse-shoes and all the various grades of m.allcable wrought and steel scrap found in a promiscuous pile of light scrap and used in the manufacture of sash, elevator and other weights, and melts them readily, producing a very hot fluid metal, and when prop- erly managed is the very best furnace for this purpose. It is to some extent used in the smelting of copper ores and the melting of copper in the manufacture of brass, and also in the melting of brass for large castings; but in melting brass, the alloy is oxidized to so great an extent that an inferior quality of brass is produced to that obtained from crucibles. Lead is frequently melted in cupolas. It melts more slowly than would naturally be expected, and it is very difficult to re- tain it in a cupola in the molten state, as it is almost impossible to put in a front through which it will not leak, and the ladle is generally heated and the tap hole left open. The quantity of cast iron that can be melted in a cupola per (272) WHAT A CUPOLA WILL MELT. 273 hour depends upon its diameter and height, and at the present time varies from one hundred pounds to twenty tons. Tiie number of hours a cupola will melt iron freely when properly managed, is only limited by the length of time the lining will last. Cupolas have been run continuously from one o'clock Monday morning until twelve o'clock Saturday noon, melting fourteen tons per hour. The size and weight of a piece of cast-iron that can be melted in a cupola at one heat, depends upon the size of the cupola. As a rule, any piece of iron that can be properly charged in a cupola can be melted. In steel-works cupolas, ingot moulds weighing five tons are melted with ease in the regular charges of the cupola. At the foundry of the Pratt & Whitney Co., Hartford, Conn., a large charging opening is placed in the cupola for the pur- pose of charging large pieces of iron to be melted, and almost any piece can be melted in one heat that can be placed in the cupola. At the foundry of the Lobdell Car Wheel Co., Wilmington, Del., an oblong cupola with charging door placed at the ends was constructed shortly after the War of the Rebellion to melt cannon and other heavy government scrap, and large cannon weighing many tons were melted in the cupola without previ- ously breaking them up. MELTING LARGE PIECES OF IRON. In jobbing and machine foundries, bad castings are some- times made or pieces purchased in scrap that are considered too large to melt in the cupola and cannot be broken with the appliances at hand for breaking. Such pieces are frequently permitted to lie in the foundry yards for years, and if thej-' chance to be bad castings, may often be buried, as we have frequently seen them, by the foreman or molders to get them out of sight. Such pieces are frequently permitted to lie in the yard through lack of knowledge of melting or of what consti- 18 274 THE CUPOLA FURNACE. tutes a large piece to melt in a cupola; and a few words on this subject may be of value. What constitutes a large piece of iron to be melted in a cupola depends upon the size of cupola. A piece weighing a few hundred weight may be a large piece for one cupola, while a piece weighing several tons may not be a large piece for another. A good way to decide this is by the weight of iron placed upon the bed when charging. A piece of iron weighing no more than the weight of small iron placed on the bed or charge is not a large piece to melt, and may be charged and melted the same as sma'l iron in reg- ular heats. Such pieces should be put in after the first or second charge, that they may have time to heat before settling into the melting zone. No extra fuel should be used in melt- ing such pieces, for extra fuel places the pieces too high in the cupola, makes the cupola melt slow, and may be the cause of failure to melt the piece. Large pieces weighing three or four times the weight of a charge cannot be melted in this way, for the piece may not all be melted, before the molien iron comes down too dull for pouring, and such pieces should be melted alone. When melting such pieces an extra bed of about six inches should be put in for the purpose of heating the iron prepara- tory to melting, before settling into the melting zone, and fuel should be placed around the piece to concentrate the heat upon it. .In this way iron may be melted sufficiently hot for casting, but if considerable fuel cannot be placed around the piece, the iron will come dull after an amount equal to two or three charges has been melted. When this occurs and the iron begins to melt slow, all the melted iron should be drawn ofT and the bottom at once dropped to prevent the unmelted piece being lodged in the cupola, and the piece again charged in the same way for an- other heat. In this way any piece of iron that can be placed in a cupola may be melted. WHAT A CUPOLA WILL MELT. 275 MELTING TIN PLATE SCRAP IN A CUPOLA. Tin plate scrap is melted in the ordinary foundry cupola the same as cast iron scrap, but more fuel is required to melt it. The best results are obtained with i pound of coke to from 3 to 4 pounds of scrap and a mild or light blast. Various ways of preparing the scrap for charging, such as hammering or pressing it into ingots and forming it into compact balls, have been tried ; but as good results are obtained by charging it in bulk, and it is generally placed in the cupola in this way. The charges are made of about the same weight as charges of iron in a cupola of similar size, but more fuel is added. The scrap when first put in the cupola is very bulky and takes up a good deal of room, but when heated it settles down into a compact mass, and takes up very little more space than a charge of cast iron scrap. Tin plate scrap settles rapidly, but melts slower than cast iron scrap or pig. Numerous attempts have been made to recover the tin de- posited upon the iron by heating the scrap in various ways to a temperature at which tin melts, but the coating of tin is so light it will not flow from the iron. All such attempts to re- cover it have proved failures. The iron, or rather steel, which is coated with tin is a very soft and tough material, but when melted the tin alloys with it, and the metal produced is very hard and brittle. The molten metal from this scrap has very little life, chills rapidly in the spout, ladles or molds, must be at a white heat when drawn from the cupola, and must be poured as quickly as possible. When not melted extremely hot the metal expands or swells in cooling to so great an ex- tent as to tear a sand mold to pieces or break an iron mold where it cannot escape. When the metal is melted very hot this expansion does not take place to so great an extent, and a sand or iron mold may be used for any work into which it is to be cast. The molten metal is more susceptible to the effect of mois- ture than iron, and is instantly thrown out of a mold when sand is worked too wet and cannot be made to lie in it. The 2/6 THE CUPOLA FURNACE. sand must, therefore, be worked as dry as possible. The metal is very hard and brittle, and only fit for sash and other weights, and even these when light and long must be handled with care to avoid breaking. The weights when rough cannot be chipped or filed smooth, and sash weights made of this metal are gen- erally sold at a less price than iron weights ; for when rough they wear out very quickly the wooden box in which they are hung, and builders dislike to use them. A foundryman who recently had a contract from the government for a number of weights of several tons each, to be used for holding buoys in the ocean, made them from tin plate scrap. When cast they were so rough that he remarked it was a good thing they were to be sunk in the mud under the ocean, for they were not fit to be seen. In a number of experiments we made in melting this scrap,, we found we could produce a gray metal from it about as hard as No. 3 pig iron, by melting it with a large per cent, of fuel and a very light blast. But the metal was very rotten and had little if any more strength than when white. We tried a number of experiments to increase its strength, but in none of them did we succeed to any extent. Melting it very hot and running it into pigs and remelting the pig improved the strength in some degree ; but this was expensive, and the results did not justify the expense. W^e also made a number of tests to learn the amount of metal lost in melting this scrap, and found with a light or proper amount of blast to do good melting there was practically no loss. With a strong blast the loss was heavier, and in one heat, with a very heavy blast, we lost lo per cent, of the metal charged. The metal from this heat was a little stronger and also a little harder, which was probably due to oxidation of the tin from the iron by the strong blast before melting. In melting old roofing tin, rusted scrap and old cans, the loss in melting varied frm lo to 25 per cent., which was probably due to rust, paint and solder used in putting the work together. Tin acts as a flux when melted with iron, and renders it more WHAT A CUPOLA WILL MELT. 277 fusible. Scrap from which the tin has been removed by acids to recover the tin or by the process employed in the manu- facture of chloride of tin, is more difficult to melt in a cupola than when covered with tin, and more fuel and time are re- quired to melt it, but a better grade of iron is produced from it. Scrap of this sort should be melted soon after the tin is removed from it, for it rusts very quickly, and when rusted to any extent produces nothing but slag when melted. Scrap sheet iron is more difificult to melt than tinned scrap and is seldom melted in a cupola, for better prices are paid for it by rolling mills than foundrymen can afford to offer. Galvanized sheet-iron scrap cannot be melted at all in a cupola in large quantities, for the zinc used in galvanizing it, acts like the zinc solution used in the Babcock fire extin- guishers, and reduces the heat in the cupola to a marked degree. When melting tinned scrap any galvanized scrap that has been mixed with it must be carefully picked out, for even in small quantities it lowers the heat in a cupola to such an extent that the metal from the tinned scrap cannot be used, and must be poured into the pig bed if it runs from the cupola at all. There are a number of ways of doctoring the metal from tin-plate scrap when it melts or flows badly, by the use of gas and oil, retort carbon, etc., but they do not improve the quality of the metal to any extent, and it is very doubtful if they increase its melting and flowing properties. A cupola of any suitable size can be employed for melting tin-plate scrap and an entire heat of the scrap may be melted alone, or it may be mixed with cast-iron scrap or pig, and melted, or again, it may be melted alone directly after a heat of iron. It is a common practice in many small foundries to melt this scrap in the cupola for sash and other weights directly after melting a heat of iron for soft castings. An extra heavy charge of fuel is placed upon the last charge of iron to check the melting for a few minutes by preventing the scrap settling into the melting zone, and the soft iron is all melted and drawn off before the scrap begins to come down. In melting long 2/8 THE CUPOLA FURNACE. heats of this scrap it is necessary to flux the cupola with lime- stone or shells in sufficient quantities to produce a fluid slag. The flux should be put in on the first charge of scrap in very- small cupolas and on the second or third charge in large cu- polas, and on each charge throughout the heat afterward. The slag hole should be placed at the lowest point consistent with the amount of molten metal to be collected in the cupola at one time, and opened as soon as the first charge of scrap, upon which flux is placed, has melted. The slag hole may be opened and closed from time to time, but it is better not to make the hole too large, and leave it open throughout the heat. The flow of slag then regulates itself, and there is no danger of it running into the tuyeres. In melting a few hundredweight of this scrap in a cupola, after melting a small heat of iron, it is not necessary to charge flux in sufficient quantities to produce a fluid slag to be tapped, unless the cupola is very small and shows signs of bunging up. In this case flux must be charged with the iron, and slag tapped early in the heat, to keep the cupola in condition to melt the scrap after the iron is melted. When constructing a-cupo]a expressly for melting tin-plate scrap the charging door or opening should be placed about 6 inches above the scaffold floor, so that the scrap may be dumped in from a barrow and save handling it a second time with forks. The charging door should be much larger than in a cupola of the same diameter for melting iron, and should be not less than 3 or 4 square feet in any case, and for cupolas of very large inside diameter the opening should be equal to one- half or three-fifths the diameter of the shell, and 4 or 5 feet high. The height of the door above the bottom depends upon the diameter of the cupola. In large cupolas it should be placed 18 or 20 feet above the bottom and in smaller cupolas as high as possible without danger of the stock hanging up in the cupola before settling into the melting zone. The lining material must be carefully selected, for poor fire brick will not last at the melting zone through one long heat; in fact, none of the fire brick lasts very long at this point, and it is generally WHAT CUPOLA WILL MELT. 279 necessary to put in a few new ones after each heat. High silicon brick is said to last belter than any other brick, but some of the native stone linings which we have described last longer in melting this scrap than any of the fire brick, and they are generally used for lining cupolas for this work. The cost of melting tin-plate scrap in a cupola is from $1 to $2 per ton more than the cost of melting iron. The amount of profit in melting this scrap for weights, etc., depends, like all other foundry business, upon the location and size of the plant and the management of the business; but at the present time, even under favorable circumstances, the profits are small. MtLTING BRASS IN A CUPOLA. The cupola furnace presents advantages not found in any other furnace for melting alloyed yellow brass, red brass, bronzes, etc. It melts these alloys more rapidly, hotter and with less fuel than probably any other furnace, and has been adopted at the United States Navy Yard, Washington, D. C. for melting allo}s for all large castings of these metals. The Southern R. R. Co. have constructed a small cupola in their repair shop foundry, Manchester, Va., for remelting axle bear- ings for locomotives and cars, and other castings, and cupolas have been installed in many other plants for this purpose. The cupola is not the best furnace for making alloys, for the more fusible metals melt too rapidly for those requiring a higher and more prolonged heat and it is difficult to obtain a definite alloy from a cupola. But copper and other metals having high melting points, maybe melted in a cupola and the more fusible metals melted in another furnace, and an accurate alloy can then be made in a ladle which had been previously well heated. In melting alloyed metals in a cupola, the loss of metal is no greater than in a crucible, and by some founders, who have made tests is claimed not to be so great. The cupola also presents the advantage of being able to mould all day, and having an hour for casting which greatly increases the output of a foundry over the method of casting when a crucible of metal is ready for pouring. CHAPTER XV. ART IN MELTING. The melting of iron in a cupola is an art that is by many foundrymen and foundry foremen but little understood, and they never begin the melting of a heat without a dread that something will happen to prevent the iron being hot enough for the work, or that they may not be able to melt the entire heat. In many foundries it is almost an every-day occurrence to have something happen in or about the cupola to prevent good melting. The sand bottom cuts through, the front blows out, the tap hole cannot be opened without a heavy bar and sledge, slag flows from the tap hole with the iron and bungs up the spout and ladles, iron and slag get into the tuyeres, daubing falls off the lining and bungs up or bridges the cupola, stock lodges upon the lining in settling, and only part of the heat can be melted. Iron melts so fast in one part of the heat that it cannot be taken care of; in another part it melts so slowly that a ladle cannot be filled before the iron is too dull for the work ; or, iron is not melted of an even temperature throughout a heat, and has to be watched in order to get hot iron to pour light work; the first iron is dull, or the last is dull, or the whole heat is dull. Some of these troubles to a greater or less extent occur almost daily, and it is a rare occur- rence in a great many foundries that a perfectly satisfactory heat is melted. In foundries in which these difficulties occur, the foundryman or his foreman, or both, do not understand melting, the cupola is in charge of an old professional melter, who always ran it in this way, or a foundry laborer or helper has been selected for a melter and given a few instructions by some one who has seen a cupola prepared for a heat, or per- haps has melted a few heats. He is instructed until he melts a (280) ART IN MELTING. 28 1 heat successfully, and then he " knows it all," and is left to himself, and perhaps he knows as much as his instructor. If he is a practical man, he learns the cause of all the troubles in melting and in time becomes a fair melter; but at what an ex- pense to his employer ! If he is not a practical man, he bungles along from day to day until he gets disgusted with his job and quits, or is dis- charged, and another man of the same kind is tried, with about the same result, for there is no one about the foundry who understands the art of managing a cupola to instruct him, and he must learn it himself, or as a melter be a failure. The foun- dryman or foreman of a foundry in which this kind of melting is done, will tell you a cupola is a very hard thing to manage, and it cannot be made to melt evenly throughout a heat or the same every heat. If this were really the case foundries making very light work, requiring hot fluid iron, would lose half their castings every heat or be compelled to pour large quantities of iron into the pig bed, and wait for hot iron. But this is not the case in stove, bench and other foundries making very light castings. Heats of many tons are melted every day, and as many pounds of iron are melted in one minute as in another from the beginning to the end of a heat, and there is not a variation of fifty degrees in the temperature of the iron from the first to the last tap. There is no chance work in nature, and there is no chance work in art when the scientific principles are understood and applied to practice, and there is no chance work in melting iron in a cupola when the cupola is scientifically managed, and there is no furnace used for melting iron more easily managed than the cupola furnace ; but it is necessary to understand its construction and mode of operation to do good melting. In the first place, the cupola must be properly constructed and of a size suitable for the amount of iron to be melted, and the time in which this melting is to be done. For fast melting, a cupola of large diameter is required, and for slow melting one of small diameter. There are those in use at the present 282 THE CUPOLA FURNACE. time in which sixty tons of iron are melted in four hours, and those in which one ton of iron is melted in four hours and a half, and each of these cupolas melts iron as fast as it can be taken care of after it is melted. The large cupola would be useless in one foundry, and the small one in the other. So it follows that a cupola must be so constructed as to be suitable for the melting it is desired to do. To melt iron hot and of an even temperature, the tuyeres must be placed low, made of a size to admit the blast freely to the cupola, and arranged to distribute the blast evenly to the fuel, and the latter must be of a proper volume for the size of cupola. To utilize the greatest possible amount of heat from the fuel, the charging door should be placed high and the cu- pola kept filled to the door until the heat is all in. When pre- paring a cupola for a heat, it must be properly ch'pped out and the lining given the best possible shape for melting, by the application of daubing. The daubing material must be of an adhesive and refractory nature and not put on so thick that it will fall off when dried or heated. The bottom door must be put up and supported by a sufficient number of props to make it rest perfectly solid against the bottom plate. The bottom sand must be of a quality that will not burn or be cut up by the molten iron, and it must be of a temper that will neither wash nor cause the iron to boil. It must be carefully packed around the edges and rammed evenly, and no harder than the sand for a mould, and given a proper pitch to cause the iron to flow to the tap hole as fast as melted. A front and spout lining mater- ial must be selected or prepared that will not cut or melt. And the front must be put in solid with a proper sized tap hole, and the spout given the right shape and pitch. The cupola having been thus prepared, it is ready for melting. Shavings and wood are put in for lighting the melting fuel or bed, and a sufficient quantity of coal or coke is put in to fill the cupola to the top of the melting zone after it has settled. As soon as this fuel is well on fire, and the heavy smoke is burned ofT so that the top of the bed can be seen, it is leveled up with a few ART IN MELTING. 2.^3 shovelfuls of fuel, and charges of iron and fuel are put in until the cupola is filled to the door. The weight of the bed fuel, and charges of iron and luel, must be learned for each cupola, for scarcely any two are charged exactly alike. It will thus be seen that the melting of iron in a cupola is very simple. But all these things and many more must be learned and practiced to make it so, and they cannot be learned in one or in a dozen heats. Sl.ig and cinder adhere to the lin- ing at one point to-day and at another to-morrow, and the chipping-out must be dififerent. The lining is burned away more at one point to-day than it was yesterday. A new lining requires a dififerent shaping than an old one, as lining burns out and the diameter of the cupola increases. More fuel is re- quired for a bed, and the weight of charges of fuel and iron must be increased. All bricks are not suitable for a cupola lining, and a good brick may be laid up in such a way that a lining will not last half so long as it would do if properly put in. All daubing material is not suitable for repairing the hn- ing of a cupola, and the best daubing is worthless when not properly applied. Bottom sand when used over and over again becomes worthless, and all sands are not suitable for a bottom. The front may be put in with material that melts, and the tap hole cannot be kept open and free of slag; or the front made of a shape that iron chills in the tap hole between taps. The spout lining material may not be suitable, and may melt and bung up the spout with slag, or the lining may be made of a shape that two or three ladles are required to catch the many streams that fall from it at the same time. To learn to manage a cupola perfectly, a close study of all the materials used in melting and their application to melting is necessary, and months of careful observation are required to learn them, but by an intelligent man they can be learned. A molder, when serving his time as an apprentice, is seldom given an opportunity to learn melting, and when he becomes foreman of a foundry knows nothing whatever about the man- agement of a cupola and is completely at the mercy of the 2S4 THE CUPOLA FURNACE. melter. The time has passed in many localities when the entire force employed in a foundry was subject to the whims of a melter and compelled to take a day off whenever he did not see fit to work, and a foreman who does not fully understand the management of cupolas is no longer considered a com- petent man to have charge of a foundry. It should be the aim of every molder who aspires to be a foreman or foundryman to learn melting, and when he takes charge of a foundry he should at once learn all the peculiarities of the cupolas of that foundry, and be able to run off a heat as well as the melter, or instruct the melter how to do it. In conversation with foremen, we have frequently remarked to them that the foreman of a foundry should be the melter, and many of them have replied that they would give up the foremanship before they would do the melting. To be a melter does not imply that the melter should perform the labor requisite to melting, for a melter may direct the melting of a heat without ever touching the iron to be melted or any of the material required to melt it. By going inside for a few minutes and giving directions how it must be done, any intelligent man can be employed to do the work, and he can be instructed from the charging door how to pick out and daub a cupola or repair a lining. He can be shown how to put up the doors and support them in place ; how to prepare daubing, front and spout material, select and temper bottom sand, and instructed from the charging door and front, how to put in a bottom front and spout lining; how to light up and burn the bed, and given a slate of charges and direc- tions for putting them in the cupola. After he has been directed by a competent melter in this way for a few heats, it is only necessary for the melter or instructor to inspect his work from time to time, to see that it is properly done and prevent the lining getting out of shape or other things occurring, in which a new melter cannot be instructed in a few days ; and his work should be inspected to prevent him getting into a rut, as melters so frequently do when left to themselves. ART IN MELTING. 285 TAKING OFF THE BLAST DURING A HEAT. The length of time the blast can be taken off a cupola after it has been in blast long enough to melt iron, and put on again and good melting done, depends upon the condition of the stock in the cupola at the time it has been stopped. The blast may for many hours be taken off a cupola that has only been in blast for a short time, is in good melting con- dition and filled with stock, if the melted iron and slag are all drawn off and the tuyeres carefully closed to exclude the air and prevent melting and chilling after the blast has been stopped. We have known a cupola in this condition in case of a breakdown in the blowing machinery to be held from four o'clock in the afternoon until eight o'clock the following morn- ing, and good melting done when the blast was again put on. In this case, the tuyeres were packed with new molding sand rammed in solid to completely exclude the air, and the molten iron all drawn off, after the tuyeres had been closed for a short time and the tap hole closed with a bod. Before putting on the blast in the morning, the tuyeres were permitted to remain open for a short time, to allow any gas that might have collected in the cupola during the stoppage to escape and avoid an ex- plosion, which might have occurred had a large volume of blast been forced into the cupola when filled with gas. Cupolas that have been in blast for some time and from which the blast is removed toward the end of the heat when the cupola is comparatively empty, or in bad shape for melt- ing, cannot be held for any great length of time, even if the tuyeres are at once closed and every precaution taken to pre- vent chilling and clogging. This is due to the gradual settling of a semi fluid slag and cinder above the tuyeres, and the clos- ing up of small openings in it through which the blast was dis- tributed to the stock ; and in case of accident to the blower it is better to dump the cupola at once than to attempt to hold it for any length of time. Cupolas, in which all the iron charged has been melted and drawn off, may be held over night, if the cupola has been 286 THE CUPOLA FURNACE. properly fluxed, the slag drawn off, and a fresh charge of coke put in, with a Hberal charge of Hmestone on top of it to liquefy any slag that may over night have chilled in the cupola. Small cupolas are frequently managed in this way; the tuyeres are closed and the tap hole permitted to remain open to admit sufificient air to ignite the fresh coke. In the morning after the cupola has been filled with stock and the blast put on, the limestone on the bed is the first to melt, and if in sufificient quantity makes a fluid slag that settles to the bottom, freeing the cupola of any clogging that may have taken place during the stoppage. BANKING A CUPOLA. Since writing the foregoing we have received the following practical illustration of keei)ing a cupola in good condition for meli-ing for many hours after it had been charged and the blast put on, from Mr. Knoeppcl, Foundry Superintendent, Buffalo Forge Co., Buffalo, N. Y. In this case melting had not begun before the pulley broke and the blast was taken off, but the same results would have been obtained from banking the cupola in this way if melting had begun and the cupola had been in blast for a short time. Mr. Knoeppel writes as follows : " Banking a cupola is something that does not come in the usual course of foundry practice, but there are times when the knowledge of how it is to be done would be a source of profit, as well as loss of time being averted. By request having been induced to allow this letter to appear in your valuable publica- tion on 'Cupola Practice;' hence will try and give you the details as near as I can from memory, although I wrote an arti- cle on this subject in the ' American Machinist,' December lO, 1891, which I am now unable to get. " In the latter part of October, 1891, just as we were about to put on the blast in our. foundry cupola and the fan making a few revolutions, the main pulley broke, running the main shaft to the fan or blower of our cupola. After considerable trouble, loss of time and delay in trying to get a new pulley, which was ART IN MELTING. 287 of wood pattern, we finally succeeded in getting one of the proper size, and had it put on the shaft ; but the belt being a little tight, and also anxious to get ofT the heat, in slipping the belt on the pulley, it was cut in such a shape that it became use- less for that day. By this time it was beyond our regular hour for quitting. At first there seemed no way out of the dilemma but to drop the bottom. The thought of re-handling the hot material and fuel, the extra labor attached therewith, suggested the idea of holding up the charges until next morning, when repairs would be completed. After a few moments' consulta- tion, proceeded as follows : Let me say first that the cupola was lighted at 1.45 p. m. and at 6 p. m began the operation of banking the cupola, havmg had four hours and fifteen min- utes' time for burning the stock, and being charged with eleven tons of metal. The cupola was of the Colliau type 60" shell lined to 44'' at bottom and 48" at melting zone, having six lower tuyeres, 7''x9'^ upper tuyeres being closed. Height of tuyeres from bottom when made up I8^^ blast pressure 10 oz., revolutions of blower about 2100, manufactured by the BufTalo Forge Co., and known as No. 10, the adjustable bed type. The cupola bed was made up of 600 lbs. Lehigh lump coal and 800 lbs. Connellsville coke, the succeeding charges 50 lbs. of coal and 150 lbs. coke, coal being an important factor in this heat on account of its lasting qualities. We first cleaned and cleared all of the tuyeres, packed each one with new coke, and then filled and rammed them tight with floor moulding sand to prevent any draft getting through them, and had the top of charges covered with fine coal and coke dust, and tightened that also to stop the draft in that direction. The object in using coal dust was this : Should any get through into the charges, it would not cause much trouble. After all was completed, gave orders to the cupola men to be on hand at 6 a. m. next morning, clean out the tuyeres and top of cupola, and ordered the men to be ready for pouring ofT at 7 a. m. The next morning all were on time. I had the tuyeres poked with bars, so that the blast might have easy access to center of cupola, and started the 288 THE CUPOLA FURNACE. blast at 7 : 15, bottom being dropped at 8 : 45 ; total time from time of lighting cupola until bottom dropped was nineteen hours. At first the iron was long in coming down and first 500 lbs. somewhat dull, but made provision for that and put it into dies, which turned out to be very good. The balance of the heat was hot enough for any kind of casting — our line being light and heavy — and had to be planed, bored and otherwise finished with some stove repair casting in with this heat engine casting, cylinder and a class of work that requires fluid metal. I am confident that if this method is carefully followed, it can be done at all times, but would not advise it in small cupolas, less than 36" inside measurement; and should the melt be in progress, it could not be successfully done at all. Should I be placed in a similar position, would resort to the same means with more confidence and certainty of success. " Yours respectfully, " John C. Knceppel, " Foundry Supt. Buffalo Forge Co., Biffalo, N. V." GIVE THE MELTER A CHANCE. There is no man about a foundry for whom we have more respect than a practical and scientific melter. He is generally a self-made man and has learned the art of melting himself. He is a man of intelligence, who, perhaps, has been a melter's helper and a close observer of the work, and when given charge of a cupola, has followed in his footsteps or improved on the methods of his predecessors. He may have been a man who was given a few instructions in melting when he first began, and has become an expert through his own efforts. He is respected by the foreman and molders, and well-paid by his employer. There is no man about a foundry for whom we have more pity than a poor melter, for he seldom melts two heats alike, and is cursed by the piece molders who have lost their work through bad iron. Gibed by the day molders, lectured by the foreman, looked black at by his employer, poorly paid, and respected by no one about the foundry, his lot is a hard one. ART IN MELTING. 289 A poor melter is not always to blame for doing poor work, for he may have been a foundry laborer who was put to work as a melter, and never given proper instruction in the manage- ment of a cupola. Again, a good melter may be made a poor one from being interfered with by others who do not under- stand melting. Foundrymen in conversing with each other learn that they are melting ten pounds of iron to the pound of fuel. The foundryman not being a practical man, does not inquire the size of the heat or cupola in which it is melted, the conditions under which it is melted, or the kind of work the iron is for. He does not stop to think that the other foundry- man may be lying to him, or is deceived by his melter and does not know how many pounds of iron he is melting to the pound of fuel. But he goes to his foundry and insists that iron must be melted at a ratio of 10 to i. The conditions in his foundry may be totally dififerent from those of the other one, and iron may not be melted at a ratio of 10 to i in the other foundry. The melter. if he is a practical man, knows this, or finds it out the first heat, and to hold his job shovels in extra fuel, unbeknown to any one, and if he is watched, does not get it in evenly or at the proper time, and the result is uneven melt- ing and dull iron, Foundrymen do not always furnish their melters with proper tools for chipping out and making up the cupola, a suitable material for repairing and keeping up the lining, a proper flux for glazing the lining and making the cu- pola melt and chip out free, and a man who would be a good melter if given a chance, is frequently made a poor one by being hampered in his work for want of tools and material to work with. He is blamed for poor melting when it is really not his fault. Good melters frequently get into a rut or certain way of doing their work, for want of text-books and other liter- ature on melting to read and study, or association with men of their calling, and become very poor melters. As a lawyer who does not read law-books that are up to the times and associate with his colleagues, becomes a pettifogger, so does a doctor who does not study his text- books and medical literature, diag- 19 290 THE CUPOLA FURNACE. noses all cases as one of two or three diseases, has one or two prescri[)tions which he prescribes for all cases. The man of learning, or a man who knows it all, when left to himself for years gets to know nothing; and so it is with melters when left to themselves. They forget many things they are not called upon to practice every day, and in time get into a rut or routine from which they unconsciously gradually degenerate if the mind is not refreshed by reading or contact with other melters. It should be the aim of every melter to converse with other melters upon cupola matters at every opportunity, and to read and study all literature upon the subject, whether good or bad ; for, if good, he. may learn something new, and, if bad, it stimu- lates the mind to reason why it is not good, and how it can be improved upon. It recalls to mind facts in his own experience which have long been forgotten, and he learns something, at all events. It is to the interest of every foundrymen who depends upon his melter for results to keep him posted upon all that is new in the business, and he should furnish him all the new lit- erature on the subject that comes into his office or is published. CHAPTER XVI. THE CUPOLA ACCOUNTS. In all well regulated foundries a cupola account of melting is kept and an accurate record made of each heat, and pre- served for future reference. In this way, the melting is re- duced to a system and the foundryman knows what is being ■done in his cupola each day and is able to make an estimate of the cost of melting. These records are also of value in showing the amount of fuel required for a bed and in charges when the cupola is newly lined, and the amount they should be increased as the lining burns out and the cupola is enlarged. Mixtures of various brands and grades of iron are recorded, with the result of the mixtures upon the quality of castings, and a great deal of experimental work in melting and mixing of irons is saved and better results are thus obtained. The manner of keeping these accounts varies in dififerent foundries. In some they are kept very simply, showing only the amount of fuel and iron in each charge and total fuel consumed, iron melted, and time required in melting. Others show kind and amount of fuel used, in bed and charges, and amount of each brand or quality of iron placed in charges, total amount melted, time of lighting up, time of charging, putting on blast, first iron melted, blast off, pressure of blast, etc. Others are still more elaborate, and not only show all the de- tails of the cupola management, but also a report presenting cost of various castings produced, good and bad, the cost of the bad ones being charged to the good ones made of the same pattern or for the same order, and the average found. To give foundrymen who have never used such reports an idea of how they are made out, we here give a few blank re- port from leading foundries. Those of Abendroth Brothers, Port Chester, N, Y., and of Byram & Co., are filled in to show the manner of placing the various items in the blank report. (291 ) 292 THE CUPOLA FURNACE. bl a; > G >. b 42 rt tn •« 1 1 c O a. o "i Pi; j i ' • • ^ •J33UOIJ Xapunoj . I o o O O o o o o o, o, o^ o^ •• B t5- - z -OM 1 I : 1 H •|B)01 pUB I ) OOOOOOOOOOOOOQ p ) ooooooocoooooo o a ^) sSjBqD qoca C ;_ q q q^ q q q q o o q o vj^ o i^ ^ JB spunoj P 1 On Os On 0» Ov Ov On CS On On On On On CO W H 1 OJ •dBJDS c > ioooooooooooooo ) ,00000000000000 8 a ■4 (3^ puB sanadg ) oooooocoooooo- 'f 1 rOfOrorofor^fOrorOfOf^fOfO-^ "T in 1 ■>*■ gj ' C 3 £ "c > oooooooooooooo c ) oooooooooooooo •XZ -ox c o qqqqqqqo^qqqqq^i- On c J a 8 ■4 c"^ r c > oooooooooooooolo 3 ^ • c ) oooooooooooooo "0 a> •yj, -ON n qqqqqo, qo^o^qo, qq^j- On (U a r i-ri-ri-ri-r»riM'i-r«^ercNr(NrN>N' 00 1^ s H e OJ c > oooooooo .00 PU a N c ) oooooooo 00 •Xe -ON n qooooooo ; 000 '2 H c r cTfrrrNereicTpr • C4 M 10 a 0. 6^ c 1 8§§S§8§8888§88 > c 9, •I -ojsj ro p \ 1 CINNNClNNNNMNNM On a N 1 P c ) oooooooooooooo •a^too spunoj c c > ! OOOOOCOOOOOUO"1 m fO a 8. a: h , c ) \r\\r^\r\xr\\ri\r\\j-\Q o O O O • » MMMNNNNOOOOO • 10 COC li-i D •|BOD spunoj c i^ p| IS > "^ ^ 1? M4 ^ 4 £ as c 00 '-' . ro c Jri d >c 1 B X - s ;? cd 1 "c in 3 V §^ c V I c c w U 3 ^" 2 "o 1 t^ 5 'u t: It ', 'T313'0-T3T)TTJ-d'0'r'0'D'T3T3 'O ^S _C a. c £ ^ ' n. ( 1 iTTTj'C'TD'Tr'a'O'O'o'o-D'u'a'n 3 "to c ( 1/ rt ^ ; I'O-C'C'CTJ-O'O'OXJTJ'U-D'^'O O CO c » t: c ) L ) ' < ' < , < ' < -< ; < ' < ■ < ; < ', < , 4 THE CUPOLA ACCOUNTS. 295 n a g < PS •jBlox pne 1 a3aEq3 qoeg 1 JO spunoj 1 •9JBIJ 3A0JS — •sanjdg •dBJOg -- — — 1 1 I I u D H ^1 i - i s u 6 H ■sanjdg S 1 •deiog 1 i u 8 c H g i .Sh J E CO H ^1 1 V * 1 5I N c3 ■5 •aiBIi 3A01S ij i e2 •9103 u B 1^1 V 1 •IE03 s 2i D d 1 •g a W "0 i i B a i CQ •a 0. 0. £ Q d i 19 m c 3 •s 1 E i 1 § 1 c 1 J ig6 THE CUPOLA FURNACE. o X m O H < u o H O w ,2 £ J5 5 - u .2 S g O|UjU|U,U,0fal33q3 ■peg •poor) •jiBiarr UI SJl{gl3_^ •o;^ uiajiEj •S333IJ JO •OJ^ •SJ9d|9{] JO "O^ THE CUPOLA ACCOUNTS. Cupola Slate for Charging and Cupola Report. J97 Coke. i c Iron. Iron. Iron. Iron. 2 0. 0. 2 IT. Total. Bed Charges — I St 2d 3d 4th 5th 1 6th 7th I 8th i 9th loth nth t2th 13th 1 Total 298 THE CUPOLA FURNACE, The blanks for these reports and records of them are fur- nished to the foundry foreman or melter, and preserved in dif- ferent ways. In some foundries they are furnished in separate sheets, and when filled out and returned are kept in files pro- vided for the purpose. In other foundries they are made out in book form and filled in by the foreman or foundry clerk. Such reports can be kept by a foundry foreman when provided with a small oflSce for doing such work; but when there is no office, as is frequently the case, a report book kept by the fore- man soon becomes so soiled that it is useless for reference, and report blanks are generally furnished in separate sheets and either filed or transferred to the report book by the foundry clerk. When only a record of fuel used and iron melted is kept, the report is generally made on a slate upon which lines are scratched similar to those in a printed report, and name and amount of various grades of iron and fuel filled in with the slate pencil. The fuel to be used and amounts of various irons to be melted in each charge are placed upon the slate by the foreman and given to the melter to charge the cupola by, and after the heat is melted the slate is sent to the foundry ofifice to be copied into the cupola account book. This latter is the oldest way of making out these reports. A cupola account is of no value if not correctly kept, and it should be the aim of every foundry foreman to see that the re- port he makes of fuel consumed and iron melted is correct, and not, as is frequently done, endeavor to make a good showing for himself, of melting a large per cent, of iron with a small per cent, of fuel, and permit his melter to shovel in extra fuel to make iron sufficiently hot to run the work. Foundrymen can readily ascertain the amount of fuel consumed by comparing the amount reported with the amount purchased. False re- ports only reduce the foreman in the estimation of his employ- ers, and are frequently the cause of him losing his position. COST OF MELTING. There is probably less known about the actual cost of melt- THE CUPOLA ACCOUNTS. 299 ing iron in cupolas for foundry work than about any other branch of the foundry business. But few foundrymen make any attempt at keeping a cupola or melting account. Many of those who do, keep it in such a way that they not only fail to learn the cost of melting, but are misled by the account to suppose their melting costs them a great deal less per ton than it really does. In the majority of foundries the melting is left entirely in the hands of the melter, who as a rule has no system for doing the work, and has no control over his assistants, or interest in having them do a fair day's work. In many of the foundries we visit, twice the number of man are employed as cupolamen as are employed in melting the same amount of iron in other foundries, where the facilities for handling the stock are almost the same; and the expense of lining and daubing material is frequently double with one melter what it is with another in the same sized cupola with the same sized heats. In many foundries the fuel is not weighed, but is measured in baskets, or the number of shovelfuls counted and the weight estimated. When the fuel is measured in baskets, the baskets always stretch and enlarge, and an old basket frequently holds one-third more than a new one; from 10 to 20 pounds more can easily be piled on the top of a basket after it is filled. Foundrymen who charge their fuel by the basket always use more of it than they estimate they are using; when the shovel- fuls are counted, each shovelful may be made to weigh more than is estimated, and a few extra shovelfuls are always thrown in, for fear some were not full. When too much fuel is used in a cupola there is not only a wastage of it, but there is slow melt- ing, increased destruction of the lining, and an increased wear and tear of the blast machinery. For these reasons every pound of fuel that goes into the cupola should be accurately weighed. Even when it is supposed to be accurately weighed, there should be some check on the melter, for he will shovel in extra fuel if not watched. At a foundry we recently visited in New Jersey a supposed accurate account of the melting had been kept for a year ; at the 300 THE CUPOLA FURNACE. end of the year the president of the company had figured up the amount of fuel consumed in the cupola and compared it with the amount purchased, and found they were short 260 tons. At another foundry, where the melter always reported melting 7 pounds of iron to i pound of anthracite coal, they ran short 300 tons in a year. This kind of work should be prevented by checking up the melter's report and comparing it with each car-load of fuel consumed. A cupola book should be provided, with blank spaces for re- cording the weight of coal or coke in the bed and charges, and the weight of each brand of iron, No. i, 2 or 3 and scrap, show- ing the exact mixture of each charge and heat. A note should also be made of the quality of iron produced from the mixture. Such a record is of great value in making mixtures and charg- ing a cupola, if it is properly kept. The cost of melting per ton is figured in a number of differ- ent ways, but to be of any practical value the entire cost of melting should be figured on as follows: Interest on cost of cupola plant and depreciation in value of same. Fire brick for relining and repairs. Fire clay, loam and sand for cupolas and ladles. Repairs to cupola, blast pipe, elevator, scaffold, runway, iDlower, &c. Belts, oil, &c., for blower. One fourth the entire cost of engine. Tools, wheelbarrows, buckets, hose, shovels, forks, rakes, hoes, sledges, picks, bars, trowels, bod sticks, tap bars, &c. Wood for lighting up and drying ladles. Coal or coke consumed in melting. Labor employed in removing the dump, making up cupola, milling dump and gates, collecting gates, scrap and bad cast- ing from foundry, placing iron and fuel on scaffold, charging, breaking and piling iron in yard, breaking up bad castings, daubing ladles, &c. When the cost of all these items has been learned, and the THE CUPOLA ACCOUNTS. JO I amount divided by the number of tons melted, it will be found tliat the cost of melting is about $2 per net ton of iron in the ladles. In foundries with all the modern improvements for handling the stock the cost is a little less than $2 per ton, and in foundries with none of the improvements for handling the stock and no system in melting, the cost per ton is as high as $3. When there is doubt as to the accuracy of weights in charging, the weights should be compared with the fuel pur- chased and castings sold, and the cost of melting may be figured on the weight of castings sold in the place of the amount of iron melted. To make a cupola report of value, the fuel, labor and tool accounts should be kept separate, and an efitbrt made to reduce the expense of each account. CHAPTER XVII. EXPLOSION OF MOLTEN IRON. Molten iron is a very explosive body, and under certain conditions explodes with as loud a report and as much vio- lence as gunpowder. Under other conditions it is not at all explosive, but those under which it explodes must be fully un- derstood and avoided by melters and moulders to prevent dan- gerous accidents. A stream of iron flows from a tap-hole and spout smoothly if the front and spout lining have been properly dried. When wet the iron explodes as it emerges from the tap-hole, and is thrown in small particles some distance from the cupola. The instant a stream of iron strikes a wet spout it explodes and the entire stream is thrown from the spout in all directions with great force. In a damp spout the iron boils and small particles may be thrown ofT, but the explosion is not so violent as from a wet spout. A wet bod causes molten iron to explode the instant it comes in contact with the stream, and it is impossible to close a tap-hole with it. A bod containing a little too much moist- ure causes a less violent explosion and a tap hole may be closed with it, but in closing it, the iron explodes and is fre- quently thrown from the tap-hole with great force past the sides of the bod before the latter is pressed into the hole. When the bod is in place in the hole one or more small explosions fre- quently take place, and the bod-stick must be firmly held against the bod to prevent it being blown out. The kick or thump felt against the end of a bod- stick when pressing a bod into place is due to these explosions, and not to the pressure of molten iron in the cupola, as is generally supposed. Bod ( 302 ) EXPLOSION OF MOLTEN IRON. 303 material should be no wetter than molding sand properly tem- pered for molding. When the iron is very hard, a stream of it when very hot throws ofif a great many sparks from a dry spout. These sparks are caused by an explosion of the iron due to the combination of oxygen with the combined carbon of the iron, and the sparks are the oxide of iron. They contain very little heat, and melt- ers or molders do not hesitate to enter showers of these sparks to stop in or catch the stream of iron. The sparks from explo- sions caused by dampness are of an entirely different character, and burn the flesh or clothing wherever they strike. A wet, cold or rusted tapping bar thrust into a stream of iron in the tap-hole or spout, causes the iron to explode. Tap bars should, therefore, always be heated before they are put into the stream of iron. When iron falls from a spout upon a hard floor, it spatters and flies in small particles to a considerable distance from the place it first strikes, and it is dangerous to go near the spout as long as the stream is falling upon the floor. When iron falls from a spout upon a wet, muddy floor, it ex- plodes instantly, and small particles of molten iron may thus be thrown a hundred feet from the cupola. If the stream con- tinues to run upon the floor, one explosion follows another in rapid succession, or a pool of molten iron is formed, which boils and explodes every few minutes, as long as there is any moisture in the floor and the iron remains liquid. The floor under a spout should always be made of loose dry sand, with a hole in it to catch any iron that falls from the spout. The floor under a cupola should always be dry, and when paved with brick or stone, should be covered with an inch or two of dry sand before dumping, to prevent fluid iron or slag in the bottom of the cupola spattering or exploding when dumped. Molten iron explodes violently when a piece of cold, wet or rusted iron is thrust suddenly into it, as the writer has reason to know from practical experience, when working at stove 304 THE CUPOLA FURNACE. moulding in the winter of 1866 and 1867. Knowing that a rusty or wet skimmer made iron explode, we always took the precaution of putting our skimmers into the foundry heating stove and heating them to a red heat before catching iron. One day we had taken this precaution, heating a skimmer to a red heat and putting it in a convenient place for use. A small boy who was around the foundry and sometimes skimmed our iron before pouring, saw the red-hot skimmer, and took it out and put it in the snow while we were catching a ladle of iron. As soon as we set the ladle on the floor he ran in with the skimmer dripping wet, and before we could prevent him, thrust into the molten iron. The iron exploded instantly and was thrown all over us as we leaned over the ladle, burning us so severely that we were not able to be out of the house for sev- eral weeks, and we still carry the scars from those burns. The iron was thrown with great violence, and passed through our clothing and a thick felt hat, like shot from a gun. The exploded iron passed over the boy's head and he was burned slightly, but never was seen about the foundry again, and prob- ably never became an iron moulder. Molten iron when poured into a damp or rusted chill-mould or a wet sand-mould, explodes and is thrown from the mould and escaping from a mould upon a wet floor or into the bot- tom of a wet pit, explodes. In the foundry of Wm. McGilvery & Company, Sharon, Pa., a deep pit for casting rolls on end was put in the foundry floor and lined with boiler plate. The first roll cast in this pit was one eleven feet long, weighing about five tons, moulded in a flask constructed in ring sections and clamped together. The mould was not properly made and clamped, and when almost filled with molten iron gave way near the bottom and permitted the iron to escape into the pit, the bottom of which was covered with wet sand ot mud. The iron at once exploded and forced its way up through ten feet of sand that had been rammed about the mould in the pit, and was thrown up to the foundry roof at a height of forty feet. The molten iron continued to explode until nearly four tons EXPLOSION OF MOLTEN IRON. 305 were thrown from the pit in small particles, and the foundry burned to the ground. Molten iron explodes when poured into mud or brought in contact with wet rusted scrap, but does not explode when poured into deep or clean water. At a small foundry that stood near the Pittsburg & Erie canal, in Sharon, Pa., many years ago, a wager was made by two moulders that molten iron could not be poured into the water of the canal without exploding. A ladle of iron was accordingly taken to the canal and poured into the water without any explosion taking place. A few days later an apprentice boy who had witnessed the ex- periment undertook to pour some into water in an old salt ket- tle that sat in the yard near the foundry and contained rusted scrap and mud under the water. An explosion at once took place that almost wrecked the foundry. The water in this case was not of sufficient depth to destroy the explosive pro- perty of the molten metal before it came in contact with the rusted scrap and mud at the bottom of the kettle. Moulders frequently pour the little iron they have left over, after pouring off their day's work, into a bucket of water to heat the water for washing in cold weather. This was a com- mon practice of the moulders in the foundry of James Mar'^h, Lewisburg, Pa., until one day iron was poured into a bucket of water in which clay wash had been mixed and contained mud at the bottom. It exploded instantly with so great a violence that all the windows were blown out of the foundry, and this stopped the heating of water for washing, in that way, at that foundry. At another foundry, iron poured into clear water in a rusted cast-iron pot, exploded, doing great damage. At the foundry of North Bros., Philadelphia, Pa., during the flood in the Schuylkill river, June, 1895, the cupola was pre- pared for a heat and the blast put on ; but before the heat could be poured ofif water soaked into the cupola pit and had to be bailed out to prevent the pit being filled. The heat was all poured before water came upon the moulding floors, but the 20 306 THE CUPOLA FURNACE. bottom of the cupola pit was soaking wet, and the melter, in his eagerness to leave the foundry before it was flooded, dropped the bottom without drawing off the molten iron remaining in the cupola. The instant the molten iron and slag dumped from the cupola came in contact with the wet floor of the pit, a violent explosion took place, scattering molten iron, slag and fuel in all directions and blowing all the windows out of the foundry. Had the melter taken the precaution to have drawn ofif all the molten iron before dumping, and thrown a few shovelfuls of dry sand under the cupola to receive the first slag to fall upon the bottom, this explosion would not have taken place. At the foundry of The Skinn?r Engine Co., Erie, Pa., a vio- lent explosion took place in their cupola which almost entirely wrecked it. At the time of this explosion, a lot of small steam cylinders were being melted in the cupola, and in some of these cylinders the ports of the steam chest had been closed by rust, leaving the steam-chest filled with water, from which it could not escape. The foreman, David Smith, had given the melter orders to see that each of these cylinders was broken before being put into the cupola, but this order had by the melter been disregarded, and the explosion was attributed to the water confined in one of the cylinders being converted into steam and exploding with such violence as to wreck the cupola. At the foundry of The Bufifalo School Furniture Co., Buffalo, N. Y., an explosion took place in 1895 in their sixty-inch cupola, about seven minutes after the blast was put on for a heat, which blew the heavy cast-iron door from the tuyere box, on each side of the cupola; and also blew out the front and broke the heavy cast-iron bottom doors. A number of men who chanced to be near the cupola were severely burned, but fortunately none were killed. This explosion was attributed to a number of causes, one of which was the formation of gas in the cupola before the blast was put on, which was exploded by the addition of oxygen from the blast. But this could hardl)' EXPLOSION OF MOLTEN IRON. 307 have been the cause, for the blast had been on fully seven minutes before the explosion occurred, and had this been the cause the explosion would have taken place almost as soon as the blast was put on. Another cause given for the explosion was that dynamite had been placed in the cupola concealed in some pieces of scrap-iron. This may have been the case, or some other explosive body may have been concealed in the scrap; but it is just as probable that it was due to steam generated from water confined in some piece of the scrap, by rusting of the opening through which it was admitted to the casting ; as in the case at the foundry of The Skinner Engine Co. A damp ladle causes iron to boil, and if the daubing is very thick may cause it to explode. A wet daubing or water in a ladle explodes the iron the instant it touches it. Wet or rusted scrap-iron placed in a ladle to chill the molten iron, causes the iron, if tapped upon it, or if thrown into a ladle of iron, to ex- plode. Such an explosion may be prevented by heating the scrap to a red heat just before using it to chill the iron. CHAPTER XVIII. GETTING UP CUPOLA STOCK. Probably the oldest and original way of placing stock upon a cupola scaffold is to lift or throw it up by hand from one plat- form to another until placed upon the scaffold. This appears to have been the only means of getting up the stock in the early days of foundry practice in this country, and this method is still practiced in many small foundries. A platform four or five feet square and probably five feet high, is constructed alongside the scaffold and fuel and iron are thrown upon it, until it is filled. The mclter then gets upon the platform, and throws the material from this upon another platform from which he again throws it upon the cupola scaffold. When the cupola is low, one platform is suflficient, and in a small foundry recently visited, we observed that the scaffold had been entirely dis- pensed with, and fuel and iron were thrown from the platform directly into the charging door of the cupola at a height of probably five feet above the platform. This method of getting up cupola stock answers very well for small cupolas melting a few hundredweight of iron, two or three times a week, and for small foundries with limited room is probably the cheapest and most practical method that can be devised for the plant. WHEELBARROW RUNWAYS. An improvement upon the above method is the runway or inclined plane constructed for wheeling up stock upon wheel- barrows. This method, which is much in use in foundries melting small heats, requires less handling of the stock and the latter may be placed upon the scaffold more rapidly and with less labor, but it requires more room than the platform, for the ( 308 ) GETTING UP CUPOLA STOCK. 309 runway has to be made long to give a grade upon which a good load may be pushed up on a wheelbarrow. When there is not sufficient room for a long runway, or in case it should terminate too far from the stock yard, it is in many plants so arranged that it runs half-way up to a platform and then makes a turn in the opposite or another direction to the scafifold. When runways are steep cleats have to be nailed upon them to insure a good footing, and an additional man is frequently required to pull the barrow with a rope in getting up a load, while with a proper runway, many cupola men wheel up 500 weight of pig with apparent ease. But these are experts and the average load is much lighter on the best of runways. TRACK RUNWAYS. A track runway is one as above described upon which a track is placed and a small car is drawn up by a chain rope or wire cable. This method replaced the barrow runway in many of the larger foundries years ago, and had the advantage of getting up stock more rapidly and with less outlay for labor. Many of these runways were very complete in design and con- struction with tracks extending to various parts of the yard upon which the cars were run to convey iron and fuel to the cupola with the least possible amount of labor in handling. This system is a good one and, if properly constructed with a good roadbed and steel rails in the yard, greatly facilitates the handling of iron from the various piles used in the mixture. A horse may be used in the yard for drawing the cars to the run- way, and if a sufficient number of cars is provided, the mixture of iron may be made when loading and the cars unloaded directly into the cupola; but when not properly designed and constructed the machinery gets out of order, rope breaks, cars jump the track, etc., making it the worst system that can be adopted. ELEVATORS. Since the perfecting of design and construction of elevators to a point where they may be run by almost any person with- 3IO THE CUPOLA FURNACE. out constantly being put out of order by sudden throwing on or off of power, overloading, lack of care, etc., they have almost entirely replaced all the methods before desciibed for the get- ting up of cupola stock. The elevator as a stock lifter presents the following advantages : It takes up very little room, may be placed at the most convenient point for unloading stock, lifts stock rapidly to the scaffold, saves time and labor; it may be used with wheelbarrows, trucks or car and a yard-track system. For these reasons they have them installed in almost every foundry plant of sufficient size to warrant their use where stock has to be elevated to place it upon the scaffold. There are a large number of makes of elevators upon the market, but for cupola work many of them are entirely too light, too delicate in construction, and easily put out of order by overloading, im- proper handling, dirt and neglect. On the other hand, there are a number of elevators upon the market especially designed for this work, and only these should be installed. Among the best of these we have seen in operation are those of The Craig Ridgway & Son Co., of the merits of which they have the fol- lowing to say : " The Steam-Hydraulic Elevator. Goes by steam or com- pressed air — steam always to be preferred. No machine ever introduced has met with such instant favor as this elevator. Hundreds are being placed in the best establishments all over the land. It is the most perfect of hydraulic elevators without the use of a pump, by simply running a small steam pipe to the nearest boiler. These elevators are rapid and do the work while other elevators are getting started. How perfect the motion is can be judged from the fact that we use the same system in foundry cranes for handling great ladles of molten iron and steel where the least irregularity of action would mean death to men and destruction to property. One of the most remarkable features of this elevator is the fact that it never gets out of order. Nothing puts it out of service but the boiler blowing up. When the boiler " lets go " no other elevator will be required ! GETTING UP CUPOLA STOCK. 311 " The cuts, Figs. 55 and 56 show the two most popular styles of the steam hydraulic elevator. " The Double Geared. — In this style all machinery is above ground. The frame is easily and cheaply made of wood by any carpenter, or, if desired, will be furnished by us. The cage has safety catches, but the best safety is the two or three separate lifting ropes. Everything is made heavy and substantial to Fig. 5 c Fig. 56. DIRFXT ACTING. DOUBLE GEARED. Stand hard work and bad usage. Hundreds of this type are in daily service. " The Direct Acting. — In this style a well is required. This is dug in the old-fashioned manner by the local well digger and walled up dry. When the water cylinder is placed upon the upper floor the head of water partly counterbalances ram and platform. The water cylinder can be placed anywhere. Note the long guides upon platform and the heavy under-bracing. This elevator is simple and easy of erection, and great numbers of them are in dail)' operation all over the land." LiniNG MAGNETS. The latest device for placing iron upon a cupola scaffold is the lifting magnet of the Electric Controller & Supply Co., an 312 THE CUPOLA FURNACE. idea of which may be gained from the illustration, fig. 57, in which the magnet is the small round device attached to the hook of the crane, and to the under side of which are attached pieces of scrap iron lifted by the magnet from the pile below. GETTING UP CUPOLA STOCK. 313 The magnet is complete in itself and may be attached for use to any traveling or swinging crane, over-head track system, etc., and used for lifting, moving or carrying iron as desired. The illustration shows a jib or swinging crane with magnet attached in use at the Baldwin Locomotive Works, Eddystone, Pa., for unloading cars of pig iron or scrap and placing it upon the scaffold or in the yard as desired. By this means a 30ton car of pig or scrap may be placed upon the scaffold in thirty min- utes without other labor than that of the crane-man being re- quired. In the same way, pig or scrap may be piled in the yard or lifted from any part of the yard within the swing of the crane and placed upon the scaffold. Iron trucks or cars with their loads may also be lifted from the tracks in the yard and placed upon a track on the scaffold, thus admitting of the de- sired mixture of iron being made from stock in the yard not within reach of the crane. The magnet may also be used for breaking up scrap by means of a drop weight, and for this purpose is said to be more effective than the old-fashioned hook for releasing the weight, the jerking of which frequently destroys the aim of the weight, resulting in failure to break the scrap as desired. The magnet system is thus the very cheap- est and quickest method that can be devised for handling cupola iron in plants melting large quantities of it. But at the present time the expense of installing this system is rather high for small foundries melting only a few tons of iron per day. This expense will no doubt be considerably reduced as the magnet system becomes more fully developed. ELEVATED STOCK YARDS. There are many foundries located near a hill or other high ground upon which their stock yards are placed upon a level with the cupola scaffold, so that it is only necessary to con- struct a barrow or track runway from the yard to the scaffold. One of the best arranged stock yards of this kind we have seen is that of the Brown & Sharpe Manufacturing Co., Providence, R. I. At this plant, which is located near a hill, a number of 314 THE CUPOLA FURNACE. Stone arched sand bins have been constructed alongside of the foundry, in which all the various grades of sand used are stored. The floors of the sand bins are on a level with the foundry moulding floor, placing moulding sand, core sand and cupola clay right at the foundry door. The top of the bins are on a level with the cupola scaffold and only a few feet from it. A driveway on the top of the bins admits of sand and clay being dumped into them from the top, and iron being piled in the yard back of the bins. A track system on top of the bins extends to the cupola, and a sufficient number of cars are pro- vided to admit of unloading fuel and iron directly into the cupola, thus reducing the amount of labor required to a mini- mum. The whole system is under roof, making this one of the most convenient and inexpensive methods of getting stock upon a scaffold and sand into a foundry that could be devised. There are many foundries in this country so situated that a system similar to this one could be readily installed at a very moderate outlay, and a great saving for machinery, power and labor effected in the handling of cupola stock, moulding sand^ core sand, cupola clay, facings, etc. CHAPTER XIX. RUNNING A CONTINUOUS STREAM. FOUNDRYMEN are realizing more and more each year the importance of running a continuous stream of iron from their cupolas instead of stopping in and tapping out. This method has the advantage over the latter system of giving a hotter iron and one of a more even temperature. Keeps the cupola in better condition for melting. Admits of tuyeres being placed low and saving fuel in the bed, and the slagging of a cupola being placed under better control. But the method of handling iron in many foundries has not admitted of this system being adopted. To overcome this difficulty a number of devices have been introduced that admit of ladles being removed and replaced without the necessity of stopping in a stream of iron. Among the best of these devices are the following: DOUBLE SPOUT. Probably the oldest device of this kind is that of the Osborne Mower and Reaper Co., Auburn, N. Y. At this plant the cupola spout is made long and divided in the center by an iron partition, in which provisions are made for a tap hole. The end of the spout next to the cupola is made two or three times the depth and width of the ordinary spout, and a lip or spout placed upon the side for running off slag. The tap hole in the cupola is made large and the slag permitted to flow into this spout with the iron, from which it is run ofT at the side. This insures a hot, fluid slag and keeps the cupola free of slag. The spout will hold from one to two hundredweights of iron when stopped in, and when it becomes necessary to stop in to change ladles, it is done in a partition of the spout. This sys- ( 315) 3l6 THE CUPOLA FURNACE. tern admits of stopping in for a few minutes and holding iron in the spout while changing ladles, and also insures a hot, fluid slag, keeps the cupola free from slag, and a low-tuyere system may be used. BASIN SPOUT. The basin spout is a broad, basin-shaped spout, resembling in shape the half of a pear, the wide part forming the basin and the narrow part, or neck, the spout. This spout is separate from the regular cupola spout, and is placed under it in such a way that it forms a continuation of it. The basin spout is pro- vided with a lug or swivel, on each side near the center, by which it is hung upon the cupola spout. A device for raising or lowering the back end of the spout by means of a lever is also provided. When raised, it forms a continuation of the cupola spout, and no iron remains in it. When lowered it forms a basin in which 50 to 100 lbs. of iron may be held while ladles are being changed, and when raised, the iron in the basin is instantly dumped into the ladle. This device places the stream under the control of the tapper for a few minutes at a time, and is one of the best in use for small bull and hand ladle work, as the iron may be held in it while ladles are being changed, and also in case hand-ladle men are not up in time to catch the stream of iron. CROSS spour. This is a spout attached to the end of a cupola spout by means of a swivel on the under side that admits of its being turned to throw the stream into a ladle on either side. This spout has been in use at the foundry of The Lobdell Car Wheel Co., Wilmington, Del., for a number of years. At this plant it is made about four feet long and used to throw the stream into a five-ton ladle on either side of the cupola spout. When one ladle is filled the cross spout is reversed to throw the stream into the other ladle. In this way a heat of one hundred tons of iron for car wheels is drawn from the cupola daily without once stopping in. This company also has a very RUNNING A CONTINUOUS STREAM. 317 neat method of disposing of their slag. The cupola spout, which is a long one, is divided in the center by an iron parti- tion, under which the iron flows. The cupola tapping-hole is made large and the slag permitted to flow out with the iron, and is caught by the partition in the spout. From the spout it is run off at a side spout and falls into a box constructed of iron plates clamped together. This box prevents the slag run- ning over the foundry floor and forms it into a solid lump Fig. r,8. S ■ S3Sli^^^* ' i f ■ ^^^H|^^^^ ^H ■ .■'^:^^W^"'^:^'^C- :{■"■■ "' from which it is only necessary to knock off the clamps when cold and remove the plate. It then may be readily broken up and removed from the foundry without making any dust or dirt as is corrimonly the case when removing hot slag from the floor. With the cross spout and this arrangement for slagging no attention need be given to either the iron or slag tap-hole from the beginning or to the end of the heat. And there is no hot slag to be cooled and removed during a heat. 3i8 THE CUPOLA P^URNACE. The cross spout may be used for a variety of purposes, and has recently been adopted by The Moyer Tramrail Co. for fill- ing tramrail ladles, as seen in the illustration, fig. 58, in which one ladle is being filled and a man stands ready to reverse the spout to fill the other one. The ladles are run to the cupola on a tramway loop that admits of them being run in either direction to the main line tramrail. This spout does not admit of iron being held in it in case of ladles not being in place to be filled, but it admits of large ladles being placed and the crane used for other purposes while one ladle is being filled. SPOUT LADLE. The spout ladle is probably the latest device for handling a continuous stream, and for many lines of casting the best one. This is an ordinary ladle of the bull type with a spout extend- FiG. 59. I . V X > ^, yx .^ >« x.\ ^ X , ^X %.^\mV^>\X\\\\\\>^ ing out on a line with the bottom as shown in Figs. 59 and 60. This spout is inclosed with a caisson of iron, the same as that of the ladle, and daubed to give an opening of four to six inches inside diameter. When placed in a position shown in I^ig- 59 it forms a continuation of the cupola spout, which may be given any desired pitch, by tipping the ladle. When it is desired to hold the stream while ladles are being changed, the RUNNING A CONTINUOUS STREAM. 319 ladle is tipped back as shown in Fig. 60. In this position it may be made to hold the stream for a minute or two while ladles are being changed. Or it may be filled to the dotted line before it becomes necessary to stop in, the stream of iron continually flowing through the ladle keeps it hot, and when tipped back the iron is not chilled by the ladle. When it is desired to fill the ladle from the spout ladle when it is full or partly full, the large opening in the spout admits of the iron being dumped from it very rapidly and the ladle filled at once. Fig. 60. The spout ladle may be constructed of a size to suit the ladles to be filled or the amount of iron that may be necessary to hold while waiting for a ladle. It may be mounted upon a permanent frame with gear for turning, or be placed upon a trestle to be turned by hand, and removed when it is desired to fill a large ladle direct from a cupola. This ladle was designed at the plant of The Brown-Sharpe Manufacturing Co., Providence, R. I., where it has been in use for several years in filling tramrail ladles holding about 800 lbs. of iron, and also other ladles of various sizes. The spout ladle in use at this plant holds 1200 lbs. when tipped back, and is 320 THE CUPOLA FURNACE. geared for turning. Its use has proven very satisfactory in this plant. RESERVOIR SPOUT LADLE. In Fig. 6i is shown the J. W. Paxson Co. Reservoir Ladle, mounted upon an iron frame, and geared for turning. De- signed for holding iron in changing ladles, as the one just de- scribed, forming a continViation of the cupola spout in filling ladles, or giving a bottom tap for skimming, by drawing the Fig. 6i. ■ --^^-^ f ■^ *.'>. I 1^ / ^-^*^ p molten iron from beneath the dirt and slag which has risen to the surface of the metal. The ladle is lipped for pouring from the top, and may be used either for bottom or top pouring by closing or opening the spout tap-hole in side of ladle. The following table gives the capacity in pounds and price of various sized ladles. Capacity in pounds. Price. ... looo 1 200 1500 1800 2000 2500 3000 50' 52 00 56 00 58 65 61 25' 68 00 66 50 Capacity in pounds. Price 3500 ^82 95 4000 89 25 4500 5000 1 6000 8coo 10,000 95 65 102 00:119 00 132 50 162 50 RUNNING A CONTINUOUS STREAM. 32 1 The capacity of these ladles when tipped back to hold iron when changing ladles is one-half that given above. When the ladle is to be used only for holding iron when changing ladles, this fact should be stated when ordering, so that the spout opening may be made large to admit of ladles being rapidly filled from it. Attention has recently been called in the foundry journals to the Reservoir Cupola, and illustrated elsewhere in this work and used in connection with the Baillot Cupola, also described in this work. This ladle may be used to form a most perfectl)' designed reservoir yet constructed; it can be employed for holding iron in slow-melting cupolas, and the iron kept hotter than in the cupola, while the slag may be permitted to flow from the cupola with the stream, and protect the iron from the atmosphere, both in the spout and ladle, and the excess of slag permitted to flow off at the lip at the backside of the ladle. When not desired to use a reservoir cupola, the ladle may be readily removed and the cupola made an ordinary one. TAPPING LADLE. Beside the new or comparatively new devices for running a continuous stream, we have the old-fashioned broad-mouth shallow tapping ladle, from which iron may be poured while the stream from the cupola is falling into it. This system has its advantages, for the iron may be skimmed in the tapping ladle before filling the pouring ladles. The temperature of the iron may be seen and the fact determined whether it is hot enough to run certain work before filling the ladle for this work. Little drops of iron left in ladles may be poured into the tapping ladle in place of the pig bed. On the other hand, it has the disadvantage of exposing a large surface of iron to the cooling action of the atmosphere, and always retaining more or less iron, which can only be emptied by stopping-in. But when the cupola is running a good-sized stream of hot iron, the iron seldom becomes dull in the short time it is necessary to hold it, and this ladle answers the purpose for which it is used very well. 21 322 THE CUPOLA FURNACE. With any of these devices, and the blast regulated to make the cupola melt a stream suited to the number of ladles in use, a continuous stream may be run from the cupola for any sized heat that it may be necessar)' to melt. The running of a con- tinuous stream from a cupola greatly reduces the liability of men being burned by iron sputtering and flying from the tap- hole due to the use of wet bod material, cold or wet tapping bars, etc. It also makes it unnecessary for men to get in each other's way at the cupola, as is always the ca'^e when catchmg over with small bull ladles. The chance of the stream getting away from the men and falling upon the floor is greatly reduced, and for these reasons one of these devices should be used in every foundry as a protection to moulders and cupol.i men. Another plan for running a continuous stream is by use of the cupola reservoir or crucible shown in Figs. 6i and 71, This system of melting has never been [)opular in this country, but is advocated by the manufacturer of the Baillot cupola, who make great claims for it. The objection to this system of melting is that the iron becomes too dull for pouring light work. CHAPTER XX. NUMBER OF MEN REQUIRED TO MAN A CUPOLA. A QUESTION frequently asked by foundrymen is how many cupola men are required to melt a given amount of iron in one or more cupolas. This is a very difficult question to answer accurately owing to the variety of conditions met with at dif- ferent foundries, such as the amount of remelt iron to be col- lected from the foundry, whether it is milled or not, distance pig iron and fuel have to be transported from stock yard to cupola, condition of yard in wet and dry weather, means of transportation, whether by wheelbarrow, track and car, horse and cart, cranes, etc., means of raising stock to cupola scaffold, whether by throwing it up from one platform to another, wheel- ing it up a runway in barrows, or drawing it up a runway with a rope or chain on cars and track, or lifting by fast or slow ele- vator, cranes, etc. These conditions increase or decrease the amount of labor required. Another element to be considered is the kind of help employed. In the south, with colored help, more cupola men are generally required to melt a given amount of iron than in the north with white or mixed help. Mr. J. W. Keep, who has recently made an investigation as to the number of cupola men required in a number of stove foundries, makes the following report in the Foundry: ( 1 ) One man does all of the work for a 2 i^^-ton melt, 3 tons being the limit. He repairs his cupola, taps out, wheels and weighs the iron, limestone and coke, wheels out the sprues and charges all of the material in the cupola. (2) Another stove foundry employing 166 moulders and melting 34 tons of iron requires only five men to operate its cupola. This includes the handling of all material, and one (323 ) 324 THE CUPOLA FURNACE. man taps out the iron while four men weigh the material and charge the cupola. These men wheel out all the sprues, and as no cinder- mill is used, pick over the bottom. However, a sixth man is employed to daub ladles and tap slag when melt- ing. The material is handled in the yard in wheelbarrows, and is hoisted to the charging floor by an elevator. (3) Another stove foundry requires six men for a melt of 2 2 tons of iron. The material is conveyed in wheelbarrows up an incline. The ladles are daubed by a separate man. (4) Another large stove foundry melting 8o tons of iron in three cupolas requires 15 men to handle the material. The iron is charged in cars handled by a crane, that reaches all parts of the foundry yard. Tlie limestone is conveyed to each charging platform by a crane. The charges are weighed and the sprews, coke, etc., are placed on the cars with the iron, and these charges are run to each cupola over tracks. Flat cars provided with boxes are used in the foundry for handling the sprues and scrap, and these after being conveyed to the yard are hoisted by the crane to the weighing platform or to a stor- age track. Fourteen cars of coke are loaded and placed on the storage tracks for each succeeding day's melt. This work requires two men in the yard, two men on the weighing plat- form, four men at each of two cupolas, and two men at the third. Including the crane operator, 15 men are required for the 80 ton melt. The ladles are daubed by another employee; the man who taps the iron also keeps the slag running. One hun- dred tons could be melted by this crew, but the distribution of the work in the foundry would necesitate the installation of an- other cupola, and therefore, four additional men. Four men could easily do the work at each of the two larger cupolas in the winter time, but in as much as an additional man has to be added at each furnace in summer, it was decided to employ the entire crew throughout the year. The melt compared with the necessary charging-floor labor can be summed up as follows. ( I ) One man 3 tons. NUMBER OF MEN REQUIRED TO MAN A CUPOLA. 325 (2) One man 6f tons. (3) One man 3^ tons. (4) One man 5^ tons. The labor of the second foundry shows that the melting is most economical in the pecentage of labor employed. "I am not certain whether uniform iron can be obtained by dumping the entire charge of coke and iron into the cupola at once, al- though in all these cases the charging was done very care- fully.— (J. W. K.). The above heats were all melted in stove foundries, in which the sprues and remelt averages about 40^1^' of the heat melted, and more time and labor are required to collect this iron than in a machine or jobbing foundry where remelt frequently does not amount to 5/0 of the heat. In small foundries it is the practice to only have one cupola man and, in case of an extra heavy heat or large ladles to be daubed, to give him a helper for a few hours. But this plan is not practicable where a num- ber of cupola men is employed for if given extra help one day, they aim to get it every day and an extra man soon has to be regularly employed to get the work done. When a number of cupola men are employed the work should be divided up so that each man has his task to do. DEVICES FOR CHARGING CUPOLAS. • The charging or placing of fuel and iron in cupolas has always been done by handling the stock at the charging door. In the handling of stock for a large rapid melting cupola more men are frequently required to keep the cupola filled than can be worked to advantage at one or more charging doors, and stock gets too low in the cupola for rapid melting. To over- come this trouble and reduce expense for cupola labor a num- ber of devices have been arranged for automatic or rapid charg- ing. At the plant of the Carnegie Steel Works, Homestead, Pa., the stacks of their large cupolas are supported on iron columns, three feet long, leaving an opening all around the cupola for charging. This opening is only a few inches above 326 THE CUPOLA FURNACE. the scaffold floor, and admits of charging being done direct from two-wheeled iron barrows of the blast furnace type, which dump from the front or end of the barrow. These barrows are wheeled from the elevator and coke or iron is dumped direct into the cupola. This method reduces the cupola labor to a considerable extent and has proven very satisfactory at this plant, where an iron of a very hot, even temperature is not re- quired. An endless chain carrying and charging device de- signed and put in use at a foundry in Indianapolis, Ind., was exhibited to the members of The American Foundrymens' As- sociation during their meeting at that city a few years ago. This device at that time was claimed to be a success, but an inquiry by the writer at this plant last spring elicited the infor- mation that it was riot then in use, and the superintendent of the foundry at that time in charge had never seen or heard of it» It therefore could not have been much of a success. An Eng- lish charging device recently described in the iron and foundry publications consists of a round iron car of the diameter of the cupola to be charged. This car is provided with a drop bottom and the charges of coke or iron properly mixed and arranged are placed in the car which is run over the cupola where the bottom is dropped and the charge dumped into the cupola. This device admits of even charging and promises more of a success than any other yet devised and put in use. Another device for direct charging that might be used to ad- vantage and no doubt will be tried in the near future, is the lifting magnet illustrated in Fig. 57. By means of this magnet, iron may be lifted direct from the yard or cars and dropped into the cupola, and only the fuel would have to be charged by hand. But like the English device above described, this can only be done when the cupola is of a sufificient height and so situated that the stack can be dispensed with. A number of other devices for this purpose that have been placed in use might be mentioned, but those described are among the best and probably sufificient to outline the work that has been done in this direction. NUMBER OF MEN REQUIRED TO xMAN A CUPOLA. 327 The great trouble with all such devices is that they do not distribute the fuel evenly over the charges of iron, and do not pack or place the iron in a cupola to utilize all the heat of the fuel. Hence the cupula does not melt iron of an even tempera- ture throughout a heat, and this has rendered all such devices unsuitable for castings requiring a hot, fluid, even iron. SMALL CHARGES FOR A CUPOLA. In an article on cupola management, written by Doctor Moldenke, and published a year or more ago in the foundry periodicals, the doctor made the claim, that by making the charges of fuel and iron light, less fuel was required, the cupola melied f.istcr, and a more even iron was obtained at the spout. Since the publication of this article a number of foundrymen have tried this system of charging and published their re^^ults. Some claim better results, while others stated that this system was a complete failure in their cupolas. The writer has met many other foundrymen who have tried the system without publishing result-^, and they report similar results, that is, suc- cess in some cupolas and failures in others. This proves the theory that I have always advocated, that every cupola is a law unto itself, and that scarcely any two cupolas can be charged exactly alike, and the best results that may be obtained pro- duced. A little investigation of cupola charging will show that there is a very wide difference in the weight of charges of fuel and iron placed in cupolas of the same diameter in different foundries, and frequently in the same foundry. This difference in weight of charges is sometimes two or three times that of the weight of others for cupolas of the same diameter. Never- theless, these varying charges give a good hot even iron from the cupola in which they are melted, which would probably not be the case were the charges reversed and the heavy ones put in cupolas melting light charges. It is therefore apparent, that to obtain the best results from a cupola, the weights of charges of fuel and iron should be varied until these results are ob- tained. Dr. Moldenke's theory is no doubt correct for many 328 THE CUPOLA FURNACE, cupolas, and especially for small ones, in which the fuel may be concentrated and in many of which the best results are obtained from small charges. But I should not recommend it for large cupolas in which a very thin layer of fuel between the charges of iron, if not very evenly distributed, is liable to permit the iron to sink below the melting zone before melting, and produce foaming slag, dull iron, or not be melted at all. RETAINING HEAT IN A FOUNDRY. Cupolas, years ago, were generally placed outside the foun- dry or in a cupola room with a spout extending into the foun- dry, but of late years they are commonly placed at the most convenient point from which to distribute molten iron to work to be cast, this being near the center of the foundry on the gangway or on the side. In this position, a cupola when not made up for a heat acts as a perfect funnel for drawing heat from the foundry during the winter months, and the coldest moulding floors are those nearest the cupola. This waste of heat may be readily prevented by placing one or two doors on top of the cupola stack, to serve as a damper when the cupola is not in blast or made up for a heat. These doors are not subjected to any great heat and' may be made of boiler plate and hinged to the top of the stack, with an arm or other device attached to each door, for raising or lowering it by means of a chain or rod from the foundry floor or scafifold. For cupolas of small diameter one door is sufificient, but for large cupolas double doors are the best, as they are more easy to raise and lower, and do not stand up so high when raised. These doors, when stood straight up, do not interfere with the draft of the cupola when lighting up, and are out of the way when the cupola is in blast. If closed as soon as the bottom is dropped, and the dump wetted a little, they retain all the heat of the dump, hot castings and warm sand in the foundry, and the foundry will be found many degrees warmer in the morning. Another way of arranging the cupola damper to prevent the NUMBER OF MEN REQUIRED TO MAN A CUPOLA. 329 escape of heat from the foundry, and at the same time to have a spark arrester over the cupola, is to hang a spark arrester over the cupola upon a lever in such a way that it may be let down upon the top of the stack by means of a chain or rod from the foundry floor or scaffold. Either of these devices may be arranged at very little cost and effect a considerable saving in fuel for heating a foundry during the winter months. PROTECTING THE MELTER WHEN CHIPPING OUT. At this time when the American Foundrymen's Association have a committee investigating accidents in foundries with a view of preventing men being injured in the performance of their daily work, it might be well to call attention to a constant danger to the melter when chipping out the cupola in making it up for a heat. In this work, heavy sledges and picks have frequently to be used to remove bridging and hard lumps that adhere to the lining, and in so doing the lining is jarred from the bottom of the cupola to the top of the stack. This jarring frequently causes bricks to fall from the top of the stack where they have been loosened by the heat and by the weather freez- ing or washing out the grouting or mortar between them ; or slag adhering to the stack lining, and deposits of oxides upon the spark arresters to drop down upon the melter, and man}' melters have been injured and some killed in this way. This danger is principally from the stack, and a very efficient and inexpensive way of lessening it is as follows: Take a board or light plank eight or ten feet long and the width of the charging door. Round ofif one end of it to the diameter of the cupola, and to the other end fix a hinged leg for a support. Attach to each side of the board with strap hinges a circular piece so that these pieces, when let down, completely fill the cupola; a cross-piece to support these wings may be nailed to the under- side. Push the board, rounded-ofF end foremost, into the cupola through the charging door, let down the wings, adjust the hinged leg under the other end of the board and place upon it a few pieces of pig iron to prevent it from being tipped 330 THE CUPOLA FURNACE. by anything that may fall upon it. This device when con- structed of light lumber is very easily adjusted and removed, and when not in use may be set on end in a corner out of the way. A device may also be constructed of boiler plate or boards, consisting of a centerpiece and two hinged side pieces to form a circle, which is braced against the Iming when in place, but such a device is more difficult to get into and hold in place than the above device. PIG BED. Pig beds for little drops of iron left over in ladles, and pig- ging out after a heat, are placed near a cupola, where they are always more or less in the way and frequently tramped over in casting, and the pig moulds destroyed. Tliis trouble may be overcome by placing iron pig moulds. Fig. 62, in the gang- way for iron from ladles, and Fig. 62. . • • 1 1 ^ constructing a pit-pig bed for pigging out. This is done by casting four plates and placing them in the floor to form a frame, the top of which comes just about level with the foundry floor. Inside of this frame the pig moulds are made in sand, to come just below the top of the frame, and covered with plates which rest upon the frame, over which a little sand may be thrown to prevent molten iron spattering in case any is spilled upon them from ladles. After the heat is over, the plates are removed with a couple of hooks provided for the purpose, and the pig moulds are ready for any over iron that may be in the cupola. This arrangement places the pig bed entirely out of the way and gives more floor space about the cupola for the handling of iron in the ladles. Another good way of protecting the pig bed is to provide a sufficient number of patterns for the entire bed and permit these patterns to re- main in the moulds until ready to pig out, when they are removed. This arrangement admits of the pig bed being NUMBER OF MEN REQUIRED TO MAN A CUPOLA. 33 1 tramped over in handling iron in ladles without destroying the pig moulds. Either of these arrangements may be found pre- ferable to forming pig moulds with a shovel and casting rough slabs of iron that have to be broken up while hot and are diffi- cult to handle and remclt. BOILING OR FOAMING SLAG. So large a quantity of slag occasionally forms in a cupola that it boils and foams until it fills the cupola to the charging door, and may run out at the latter. This phenomenon gener- ally occurs at the end of the heat, and is due to too small a quantity of fuel being used between the charges of iron, and the latter sinking too low in the melting zone before melting. At this point, when in a semi molten state, it is struck by a strong blast from the tuyeres, which has a bessemerizing effect uDon it, and a large per cent, of it is converted into slag, which is made to boil and foam in the cupola by a strong blast pass- ing directly into it from the tuyere. This slag contains a large per cent, of iron, and the loss of the latter in melting is very heavy. Boiling slag may also be due to uneven distribution of fuel, or an excess of it being thrown upon one side of the cupola. In this case the slag is only formed on one side of the cupola or in front of one or more tuyeres, and if the trouble is soon remedied by an excess of fuel settling down at this point, the only effect will be to produce an excess of slag at the iron or slag tap hole. But if this does not occur, the cupola only melts on one side and the iron is made dull and harder by oxidized iron mixing with it, and when stock gets low in the cupola, the slag boils and foams up to the charging door, and melting al- most entirely stops. When a cupola gets into this condition, the only thing to do is to drop the bottom, and this should be done before the blast is taken ofT, to prevent the tuyeres and air chamber from being filled with slag. 332 THE CUPOLA FURNACE. TREATMENT OF BURNS. In many of the large foundries scarcely a day passes but men are burned in handling hot iron in ladles. Linseed oil and lime water are generally kept at hand for the treatment of such burns. But this remedy is slow in action and difficult to keep in place, and small burns are frequently neglected, result- ing in bad sores. A much better remedy is a fine grade of new moulding sand moistened with glycerine to the consistency of a thin putty. This remedy, if at once applied, draws out the fire very quickly and admits of the burn healing rapidly. A small piece of gauze or thin white cloth placed over the burn before applying the remedy keeps the burn clean and does not interfere with the action of the remedy. For drawing the fire put the remedy on thick, and for healing spread it on very thin. Another good remedy is antiphlogistine, a preparation of white clay sold in drug stores. This preparation acts very similarly to the moulding sand remedy and is applied in the same way. It is however much cleaner, and may be applied direct to the burn for healing, and washed ofT when dressing the burn. Should this or the sand remedy draw the sore too much for rapid healing, apply a thinner layer. Sores from burns are retarded from healing by exposure to the air, and should only be dressed once a day, and if kept clean, once in two or three days is sufficient. If no other remedy is at hand a little clay from the cupola daubing trough is a good one for drawing the fire from a burn and giving prompt relief. Apply it thick and tie it up to ex- clude the air. NEW METHOD OF MIXING DAUBING. In some of the larger foundries using a great deal of daubing material, it has been found to be more economical to dry and grind the clay before mixing it with the sand, than to soak the the clay and mix the sand after soaking. A common stave tumbling barrel is provided for this purpose. The clay is n NUMBER OF MEN REQUIRED TO MAN A CUPOLA. 333 thrown into the barrel with a proper amount of pig iron to break it up and reduce it to a powder. When this has been done, the clay is again thrown into the mill with the proper amount of sharp or fire sand, and the two thoroughly mixed. The mixture is then placed in a mixing trough and wetted up and, while the mill man is waiting for a mill full to be ground, he hoes it over and makes it ready for application to the cupola. This method gives an even mixed daubing that does not crack when heated or fall ofT in spots from containing an excess of clay or sand. It is also claimed to save considerable time and expense, for it is said, that in no part of cupola manipulation can cupola men put in more time than in hoeing over a trough of daubing. This method also has the advantage of reducing the mixing of daubing to a science, for it enables the founder to accurately determine the per cent of clay and sand, that gives the best re- sult in melting from the grade of clay and sand used, and to determine if a difTerent grade of either would give better results. This is a matter which cannot be accurately determined with any degree of certainty when cupola men are depended upon to do the mixing, because in many cases the greatest quantity of material that is easiest to shovel and mix, is used regardless of results obtained in melting, This system of mixing is applicable to small as well as large plants, as an ordinary tumbling barrel may be used for the grinding and mixing, and when mixed, the material may be binned or barreled. It is then only necessary to wet and hoe it over to ensure an even temper of the daubing. Grinding and mixing may also be done in any of the sand mixers used in foundries, but in this case the cla}' must be per- fectly dry and broken small to prevent clogging in the mixer. Another way of mixing daubing is by the wet process in the roller mill. With this mill no drying of the clay is necessary, and when mixed, the daubing is ready for application to the cupola. However, only foundries using rope cores, coated with loam, or doing a large amount of loam work, have this 334 '^"HE CUPOLA FURNACE. mill in use, and it is too expensive to install for this purpose only in any but large plants. RENEWING A LINING. In many of the large cupolas, melting from fifty to one hun- dred tons of iron at a heat, the destruction of lining material is very great. Four inches of lining are frequently burned out at the melting zone in one or two heats, and this thickness of lin- ing seldom lasts more than a week before it has to be renewed with new brick. A good plan of renewing this lining, is to place in the cupola at this point a lighter permanent lining than desired, and inside of this lining place a lining of four-inch brick to reduce the cupola to the desired diameter. Such a lining is equally as refractory as the permanent lining and may be removed and rejjlaced with new brick in a very short time without disturbing the permanent lining. This method of re- newing a lining has proven very satisfactory in a number of plants melting large heats, and may also be adopted by those melting small heats in which the destruction of lining is heavy. MICA SCHIST LINING. Mica schist * or fire stone, as it is sometimes called, is a soft rock that has been used for some time in lining steel convert- ers and furnaces, and is now coming into use for cupola linings. This material may be readily broken, and crumbles easily when handled, and cannot be cut into shape for lining before ship- ment. It is therefore used in its natural state as it comes from the mines and fitted to the cupola as the lining is laid up. The small pieces or crumbs that are broken off in handling and fitting the lining are mashed up and mixed with a little fire clay ; this makes a fire mortar that stands the heat equally as well as the solid rock, and when heated cements the entire lining * Mica schist, although an excellent lining material, does not appear to have come into use to any gn-at extent as a cupola lining sin^e the publication of the second edition of this work. The great objection to it appears to be the time required for putting in a lining. NUMBER OF MBN REQUHIED TO MAN A CUPOLA. 335 into a solid mass that glazes and does not spall off and fall out so easily as fire brick. At several foundries where this lining was being used we were informed that it was giving excellent results, and required less daubing and repair than fire brick. At one large foundry where a lining of this material had only recently been put in, we were told that the lining material for their cupola had cost less than one-fourth the cost of fire brick for the same cupola ; and while the cost of putting it in was a little greater, the lining when in had cost less than one-half that of fire brick, and in the few heats they had melted with it, it had not been cut out to so great an extent as with brick. When putting in a lining of this material all backing or fill- ing put in with fire brick should be removed and the lining made as thick as possible, for the thicker it is the more readily and quickly it may be laid up, and a backing is not required with it. There are several other native lining materials in the market, such as ganister and mica soap-stone, that may be used to advantage when cost of transportation is not too great. COMMON RKD BRICK LINING. The question of lining with common red brick bobs up every once in a Vv'hile as something new, cheap and economical. We have seen many cupolas lined with this material in days when fire brick was not so cheap or easily obtainable as at the present time. The softer bricks were generally selected, and they were set on end with the edges to the fire, and two thicknesses of them were generally put in. These linings answered the purpose very well for the small heats commonly melted in those days, but with the heats melted in many cupolas at the present time it is doubtful if they would last through one heat; and even when heats are light, they are a more costly lining in the long run than the more expensive fire brick or other material, for they require to be replaced very frequently at the melting zone, which neces- 336 THE CUPOLA FURNACE. sitates taking a day or having the melter and helper work on Sunday, and this in time costs more than good lining material. Use only the best of lining material and the best of daubing material for keeping it up, and you will reduce cost of melting more than by using cheap material. moor's patent cupola breast and runner. The breast and spout are made of the same material as a plumbago crucible for melting steel or brass, or of fire clay, and baked in an oven the same as crucibles and fire brick. This breast and spout are designed to replace the common loam and clay breast and spout made up every heat and save material and labor in making them up. The runner is made to order to fit the cupola spout, the iron running over it to the ladle. It will last for three or four years with care. Runners are also made for slag spouts or in fact any spout where iron, steel or brass is run. It saves the clay or loam to make and mend it, and the time in doing so. The breast will not only do away with the old clay or loam breast, but relieves the foreman of much responsibility. It should last six to eight months. The breasts are kept in stock and may be readily fitted to any cupola. With this breast and spout always in place, it is only necessary to make the sand bottom up to suit the tap hole and much material and labor are saved. The size of tap hole may be regulated by use of thimble or ring, or by placing a bod in the hole and making an opening through it of any desired size with a tap bar. These are the claims made for this breast and spout. CHAPTER XXI. SCIENTIFICALLY DESIGNED CUPOLAS. That the cupola designer has not been idle will readily be seen by the following illustrations and descriptions of a few of the many designs of cupolas that have been constructed and placed in the foundries of this and foreign countries. Each of these cupolas embraces some practical or scientific point not found in the others, and designed to better suit it for the work to be cast, fast melting, slow, continuous melting, holding mol- ten iron, economy in fuel, blast, lining material, labor, etc. Each of these cupolas presents some fine points in melting or other purpose for which it was designed, and was no doubt a great improvement over the one it replaced, but it is much easier to design and construct a cupola upon scientific lines with fine points than it is to maintain it. Thus a flat cupola admits of blast being more evenly distributed to the stock than a round one, but the increased tendency of the cupola to bridge and bung up, and lining to collapse, makes this design imprac- ticable. Some of the various shaped linings present scientific points in the distribution of blast and settling of the stock, but the difficulty of maintaining the lining in this shape renders these points useless. The arrangement of tuyeres and distri- bution of blast upon scientific principles has produced perfect combustion of fuel, rapid and economic melting, but changes in shape of lining, difficulty of keeping small tuyeres open, etc., have destroyed this effect. Another objection to these scien- tific, fancy-designed cupolas is the class of men employed in manipulating cupolas. As a rule these men are not scientists, and cannot see the advantages of maintaining the finer points, and while one melter may manage one of these cupolas suc- cessfully for years, the next one may make a complete failure 22 (337) 338 THE CUPOLA FURNACE. of it. For these reasons the fancy-shaped or designed cupola has as a rule been forced to give place to the straight-line, cylindrical one with abundant tuyere area and high charging door, which is more easily manipulated than any other with the help obtainable, and while it may not give the best results indi- cated by science, it gives the best practical results for the founder, OLD SlYLE STAVE CUPOLA, In Fig. 63 is seen the old style cupola in general use through- out the country many years ago, some of which are still in use in old-time small foundries. A square cast-iron bottom plate, with opening in the center and drop door, is placed upon a brick foundation at a sufificient height above the floor for the removal of the dump. An iron column is placed upon each corner of the plate, and upon these columns is placed another cast-iron plate, having an opening in the centre for the top of the cupola. Upon this plate a brick stack is constructed to carry ofT the flame and unconsumcd gases. The stack plate was sometimes placed upon brick columns or brick walls, built on each side of the cupola, through which openings were made for manipulating the tuyere elbows. The stack was built square and of a much larger size than the inside diameter of the cupola. It was not subjected to a very high heat, and was built of common red brick. These large stacks were not built very high and threw out very few sparks at the top, which was due to their size. The cupola was placed between the bottom and stack plate, and the casing was formed of cast-iron staves, which were held together by wrought-iron bands, drawn tight by draw-bolts placed through the flanged ends of the bands. When the casing was made tapering, the bands were placed in position when hot and shrunk on. The cupolas were only from six to eight feet high, and those of small diameter, were generally made larger at the bottom than at the top, to facilitate dropping, and that a large quantity of molten iron might be held in the cupola for a heavy casting. SCIENTIFICALLY DESIGNED CUPOLAS. 339 The charging door was placed in the stack just above the stack plate. From two to four tuyeres were put upon each side of Fig. 63. OLD STYLE CUPOLA. 340 THE CUPOLA FURNACE. the cupola, one above the other, and from eight to ten inches apart. The tuyeres were supplied from a blast-pipe on each side, to which was attached a flexible leather hose and a tin or copper elbow for conducting the blast into the tuyeres. A small hole was made at the bend of the elbow for looking into the tuyere, and closed with a wooden plug. The tuyeres were frequently poked with an iron bar through these openings. When light work was to be cast, the upper tuyeres were closed with clay or loam, and the blast sent through the lower tuyere. When it was desired to accumulate a large amount of molten iron in the cupola for a heavy piece of work, the lower tuyeres were used until the molten iron rose to the lower edge. The tuyere elbows were then withdrawn and shifted to the next tuyere above, and the lower tuyere closed with clay or loam rammed in solid. The shifting of the tuyere elbows was con- tinued in this way until the necessary amount of molten iron for the work to be cast was accumulated in the cupola. When a heavy piece of work was to be cast, a sufificient quantity of fuel was placed in the cupola to bring the top of the bed some distance above the top of the highest tuyere to be used ; on the bed two cwt. of iron was charged, and a shovelful of coke and a cwt. of iron charged throughout the heat. The charging was raised a little in different sized cupolas, but the fuel and iron were always mixing in charging. The large body of molten metal frequently pressed out the front and sometimes the plugging of the lower tuyeres. After the iron was tapped the stock in the cupola dropped so low that no further melting could be done with the blast in the upper tuyeres, and fre- quently the lower tuyeres were so clogged that they could not be opened, and the bottom had to be dropped. In practice it was found that in a cupola constructed large at the bottom and small at the top for the purpose of retaining a large amount of molten iron, the stock did not spread to fill the cupola as it settled, and a great deal of heat escaped through the space made between the lining and stock by the settling of the latter. It was also found that the shifting of tuyeres re- SCIENTIFICALLY DESIGNED CUPOLAS. 341 •quired Jsuch a high bed that the cupola melted slowly, and a greater per cent, of fuel was consumed in large than in small heats. Fic.. 64. RESERVOIR CUPOLA. 342 THE CUPOLA FURNACE. THE RESERVOIR CUPOLA. To overcome the objection to the tapering cupola and shift- ing of the tuyeres, and still be able to hold a large amount of molten iron in a cupola, the reservoir cupola, Fig. 64, was designed. The casing of this cupola was made of wrought iron, and the bottom section, to a height of from twelve to twenty-four inches, was constructed of one-third greater diameter than the upper section or cupola proper. This arrangement admitted of a large body of molten iron being held in the cupola without shifting the tuyeres. The metal was spread over a larger sur- face, which reduced the pressure on the breast, and did not leave the stock in so bad a condition for melting after a large tap was made as in the tapered cupola, and melting could be continued after a large body of iron was tapped. The reservoir cupola did faster and more economical melting in large heats than the tapered cupola, but in small heats the amount of fuel required for the bed was too large for economical melting. At the present time cupolas are made of the same diameter from the bottom to six or eight inches above the tuyeres. The tuyeres are placed at a height to suit the general run of work to be done, and when a heavy piece is to be cast, the iron is held in ladles and covered with charcoal or small coke to ex- clude the air. The molten iron can in this way be kept hotter for pouring than in the cupola, and the cupola is kept in better condition and melts faster and longer. EXPANDING CUPOLA. Fig. 65 is a sectional elevation of the expanding cupola, which is said to have melted very rapidly and with very little fuel. This peculiar form was designed to admit of the charging of a large quantity of iron before putting on the blast, for the purpose of utilizing all the heat produced by the com- bustion of the fuel. These cupolas were built of common brick, banded with wrought- iron band and lined with firebrick. The diameter at the charging door was sixty inches and at the SCIENTIFICALLY DESIGNED CUPOLAS. Fig. 65. 343 EXPANDING CUPOLA. 344 THE CUPOLA FURNACE. tuyeres thirty inches, or one-half the diameter at the charging door. Below the tuyeres the lining expanded to forty or even fifty inches, to give room for molten metal. The bottom was stationary, and the refuse after meltmg was drawn at the front. The cupola expanded from a level a little above the tuyeres to the bottom of the charging door, thence to the top of the stack it gradually contracted. The greatly increased diameter at the charging door certainly admitted of a large quantity of iron being placed in the cupola at one time, and the utilization of a very large per cent, of the heat in melting. The even taper of the lining insured the even settling of the stock, so that good melting should have been done in this cupola ; but the best results obtained appear to have been about six and a half pounds of iron to the pound of coke. This old form might be used to advantage in the construc- tion of very large cupolas ; but in the ordinary sized cupola, practically the same results are obtained by boshing or con- tracting the lining at the tuyeres, and making it straight from the top of the boshes to the charging door. Ireland's cupola. Ireland's cupola, for which the inventor took out a number of patents in England about 1856, and which was largely used there about that time, and is still the leading cupola in England, was constructed of a variety of shapes and sizes, but probably the best design is that shown in sectional view Fig. 66. It is built with a bosh and contraction of the diameter at the tuyeres, and has a cavity of enlarged diameter below them to give in- creased capacity for retaining molten metal in the cupola. The cupola, of which a section is shown, was twenty-five feet high from bottom plate to top of stack, twelve feet from bottom plate to sill of charging door. The shell was parallel and fifty inches diameter to the charging door, thence it gradually tapered to two feet three inches at the top. There were two rows of tuyeres eighteen inches apart, eight in the upper row, two inches diameter, and four in the lower row, six inches SCIENTIFICALLY DESIGNED CUPOLAS. 345 •diameter. The cupola was constructed with stationary bottom -and draw front. Fig. 66. Ireland's double tuyere cupola. 346 THE CUPOLA FURNACE. It was at first proposed to use a hot blast in the top row of tuyeres, but it was found to be difficult and expensive to heat the blast, and that nothing was gained by using the upper row with a cold blast, and they were closed and the cupola con- structed with only the lower row of tuyeres. The interior shape was slightly modified to give more space for retaining molten metal, while, at the same time, retaining the boshes and in- creasing the diameter of the bottom of the cupola, as seen in the Fig. 66. Two of these cupolas were used by the Bolton Steel and Iron Company in England, in melting the iron for a large anvil block weighing two hundred and five tons, for which two hundred and twenty tons of metal, including eight tons Bessemer steel, were used. The cupolas were each seven feet outside diameter, three feet nine inches diameter below the boshes in the crucible, and five feet diameter above and below the crucible. The blast was sup- plied from an external air-chamber, extending round the casing and delivered into the cupolas through two rows of tuyeres placed eighteen inches apart, sixteen in the upper row of three inches diameter, and four in the lower row of eight inches diam- eter. The metal was melted in ten hours and forty-five minutes from the time of putting on the blast until the mold was filled, and only one hundjed and twenty-five pounds of coke con- sumed per ton of metal. Slag was tapped from the slag hole A below the tuyeres throughout the heat. Ireland's center blast cupola. In Fig. 6y is seen a sectional elevation of Ireland's cupola with bottom tuyere. The height from bottom plate to top of stack is twenty-seven feet, from bottom plate to sill of charging door twelve feet. The casing is parallel from the bottom plate to charging door, and thence it gradually tapers to the top ; diameter of casing up to charging door four feet six inches, tapering to two feet six inches at the top of stack. The inside diameter at bottom of crucible, on the cupola hearth L, is two feet six inches, contracting to two feet three inches at spring of SCIENTIFICALLY DESIGNED CUPOLAS. Fig. 67. 347 IRELAND'S CENTER BLAST CUPOLA. 348 THE CUPOLA FURNACE. the bosh A A, and three feet nine inches diameter from top of bosh to charging door, whence it tapers to one foot nine inches at top of stack. Height of crucible four feet five inches, length of boshes from AA to BB, eighteen inches; height from top of bosh to charging door, six feet seven inches. The blast is sup- plied from one tuyere placed in the center of the bottom of crucible. The tuyere hole through the iron bottom is nine inches diameter, into which is passed a seven and a half-inch water tuyere, the mouth of which, //, is two feet above the sand bottom L. A slag hole A'^, five inches diameter, is placed just below the level of the mouth of the tuyere. P is the tap-hole and spout. This cupola melted three tons of iron per hour with two and a-half cwt. of coke per ton, but it does not appear to have given satisfaction, for it never came into general use in England or this country, and Mr. Ireland changed his plans and constructed his cupolas with side tuyeres. voisin's cupola. In illustration Fig. 68 is seen a sectional elevation of Voisin's cupola, in which very good melting has been done. The shell is constructed of boiler plate with an external air chamber of the same material, extending all the way round the body of the cupola. This air chamber is supplied from two pipes, one on each side of the cupola. Two sets of tuyeres lead from the air belt into the cupola. Those of lower ,set are oblong, four in number, placed at equal distances apart and at right angles to the air belt. Those of the upper set are round, of less ca- pacity than those of the lower set, are placed horizontally through the lining and diagonally to the lower set, so that they are between them at a higher level. Mr. Voisin claims through this arrangement of the tuyeres, that the escaping gases are burnt in. the cupola, creating a second zone of fusion with those gases alone, and the second set of tuyeres obviates to some extent the evil effect of the formation of carbonic oxide in the cupola. SCIENTIFICALLY DESIGNED CUPOLAS. Fig. 68. 349 voisin's cupola. 3 so THE CUPOLA FURNACE. This cupola is constructed in slightly varying shapes inside the lining, but the following dimensions give a general outline of it: Vertical dimensions from bottom to offset below tuy- eres, one foot ten inches ; offset below tuyeres to lower end of bosh, two feet four inches; length of bosh, one foot two inches ; top of bosh to charging door, six feet ten inches ; bottom of charging door to bottom of stack, two feet seven inches; taper to stack, three feet ten inches Horizontal dimensions: Below tuyeres, two feet; at tuyeres, one foot eight inches; at top of bosh, two feet four inches; at bottom of charging door, one foot ten inches ; at charging door, two feet seven inches. The casing is made straight from the bottom plate to taper to the stack, and to get the above dimensions it has to be lined with brick made especially for this cupola. Mr. Voisin has invented a number of different cupolas, but this one is said to give the best results in melting. woodward's steam jet cupola. In Fig. 69 is seen a sectional view, showing the construction of the Woodward steam-jet cupola in use to some extent in England. This cupola is worked by means of an induced cur- rent or strong draught caused by a steam-jet blown up the cupola stack, which is very much contracted just above the charging door. There are several different modes of applying the steam-jet, but the general principle will be at once under- stood from the illustration. The cupola is constructed upon the general plan of the English cupola, with a stationary bot- tom and draw front. Two rows of tuyeres or air-inlets, as they are termed, are placed radially at two different levels. In the lower row there are four openings, varying in size from five to eight inches in diameter, according to the size of the cupola. In the upper row there are eight, varying in diameter from three to five inches. Each of the air- inlets is provided with a cover outside, which can be closed when it is desired to shut off the draught. The upper row of air-inlets is placed from ten to SCIENTIFICALLY DESIGNED CUPOLAS. Fig. 6q. 351 WOODWARD STEAM-JET CUPOLA. 352 THE CUPOLA FURNACE. fifteen inches above the lower row. The lining is contracted at the air-inlets to throw the air to the center of the stock, and en- larged below the air-inlets to admit of the retention of a large amount of molten iron in the cupola. The charges of fuel and iron are put in at the charging door A in alternate layers in the ordinary way, and the door is tightly closed and luted to prevent the admission of any air. The steam is then turned on through the nozzle B connected with the boiler by steam-pipe D, and the air-inlets N opened for the admission of air. When the cupola is working, the draught has to be regulated by the melter and care taken to close any air-inlets near which iron is seen to accumulate in a semi-fluid state. The temperature at the spot where the iron chills will soon rise to a degree that will cause the iron to run freely, when the air-ii^let may be again opened. All the iron to be melted is put in and the door closed before the steam is turned on. The charging may be continued throughout the heat, but the opening of the door has the same efTect on the stock as shutting off the blast in the ordinary cupola, and the melting stops. The repeated opening of the door soon gets the cupola into bad working order and it bungs up in a short time. When it is desired to use the cupola for continuous melting or for a larger amount of iron than can be put in at one time, it is constructed with a side flue and feeding hopper, as shown in Fig. 70. The general construction and air inlets are the same as those shown in Fig. 69. The stack is removed and the feed- ing hopper A with a sliding door B at the bottom, to be worked by the lever D, is placed on top of the cupola. The flue // near the top of the cupola connects it with the stack M, and the draught is induced by a steam- jet from the nozzle TV attached to the steam-pipe P. When filling the cupola, the bottom of the hopper is left open and the charges put in in the ordinary way until the cupola is filled. The bottom door of the hopper is then closed, and when the cupola is melting the charges of fuel and iron are put into the hopper and dropped into the cupola as the stock settles, and the door is at once closed to exclude the air at the top of the cupola. I SCIENTIFICALLY DESIGNED CUPOLAS. Fig. 70. 353 woodward's steam-jet cupola. 23 354 THE CUPOLA FURNACE. It is asserted by those interested in this cupola that it effects a great saving in fuel over the ordinary blast cupola. The con- sumption of coke in melting a ton of iron is placed at one hun- dred and fifty pounds, a very low rate of fuel ; but the same results are also claimed to have been obtained in blast cupolas of good design when properly worked. The steam required to create the draught is only equal in quantity to what would be required by an engine for driving a fan or blower of sufficient power to work an ordinary cupola of the same size. Considerable saving is effected in the first cost of engine and fan or blower, besides the saving in wear and tear of machinery. The objection to this style of cupola is the slow melting, for it cannot be forced beyond a certain point, and when a large amount of iron is to be melted the cupola must be kept work- ing all day. This does not meet the views of the foundrymen of this country, who desire to melt their heats in from one to two hours from the time the blast is put on until the bottom is dropped, and with that object in view construct their cupolas. TANK OR RESERVOIR CUPOLA. In Fig. 71 is seen a sectional elevation of a reservoir cupola. This cupola was designed for the purpose of making soft iron for light castings. It only differs in construction from the ordinary type in the reservoir or tank placed in front, which may be attached to any cupola. The cupola is set high, and the tank A is placed in front of it, with the cupola spout leading into it near the top. The molten iron is run from the cupola into the tank as fast as melted, and drawn from the tank-spout into the ladles as it may be required for pouring. The tank is made of boiler plate and lined with fire-clay or other refractory material, and is covered with an iron lid, lined likewise with same material. The spout and breast are made up the same as for an ordinary cupola. Before putting on the blast, the tank is filled with charcoal and closed with the cover; and as the iron melts, it is run into the SCIENTIFICALLY DESIGNED CUPOLAS. Fig. 71. 355 TANK OR RESERVOIR CUPOLA. 356 THE CUPOLA FURNACE. tank, where it is allowed to remain a sufficient length of time to be carbonized and softened by the charcoal. These cupolas have been constructed in a number of differ- ent ways; the tank has been made of sufficient size to hold the entire heat of molten iron before pouring, so that the iron might be of an even grade throughout the heat and softened to a greater extent; and they have been riveted to the cupola casing and the lining continued from the cupola to the tank. In this latter case, the top is bolted or clamped to the tank and a tight joint made to prevent the escape of the blast, which has the same pressure in the tank as in the cupola. The tank cupola produces a softer iron than the ordinary cupola, but there is considerable additional expense attached to it in keeping up the tank and supplying it with charcoal. Another objection is the change made in the shrinkage of the iron ; that taken from the tank shrinks less than the same grade of iron when taken from the cupola, and when some parts of a machine or stove are made from the tank and other parts from the cupola, allowance must be made in the patterns for the difference in shrinkage. It is claimed by some founders that soft iron can be pro- duced by putting a quantity of charcoal on the sand bottom, and placing the shavings and wood for lighting the bed on top of the charcoal. In lighting up, the charcoal is not burned,, but remains in the cupola during the heat and may be found m the dump. This is the case if the tuyeres are high and the front is closed before lighting up; but if the tuyeres are low or the front and tap-hole are not closed, the charcoal will be burned out in lighting up the bed, the same as the wood. Tanks are, in England, used in connection with cupolas to som.e extent at the present time for mixing irons or to enable the founder to run a large casting or heat from a small cupola. The iron for an entire heat, requiring several hours to melt in a small cupola, is melted and run into the tank and drawn from the tank into the ladle at casting time. This makes a well- mixed and even grade of iron in all the castings and saves con- SCIENTIFICALLY DESIGNED CUPOLAS. 357 siderable time in casting, as the molders are not obliged to wait for iron to melt, as is often the case. MACKENZIE CUPOLA. In Fig. T2 is shown a sectional elevation of the Mackenzie cupola, designed by Mr. Mackenzie, a practical foundryman. When this cupola was designed the only one in use was the common straight one with a limited number of very small tuyeres and low charging doors, and it melted very slowly. It was the custom in foundries at that time, to put on the blast at one or two o'clock and blow all the afternoon in melting a heat. Molders generally stopped molding when the blast went on and a great deal of time was lost in waiting for iron. To save this time and get a few hours' more work from each molder on casting days, Mr. Mackenzie conceived the idea of constructing a cupola that would melt a heat in two hours from the time the blast was put on until the bottom was dropped. He had dis- covered that the tuyeres in common use were too small to admit blast freely and evenly, and cupolas did not melt so well in the center as near the lining and tuyeres. To overcome this fault in the old cupola, and admit the blast to the stock evenly and freely, a belt tuyere was put in extending around the cupola, and to place the belt nearer to the center of the cupola at the tuyeres, the lining was contracted or boshed at this point. To avoid reducing the capacity for holding molten iron below the tuyeres, the lining just above the tuyeres was sup- ported by an apron riveted to the cupola casing and the bosh made to overhang the bottom, leaving the cupola below the tuyeres of the same diameter as before boshing. This cupola, when first mtroduced, was known as the two- hour cupola, and wrought a great revolution in melting and in foundry practice. Heats that had required half a day to melt were melted in two hours, the quantity of fuel consumed in melt- ing was reduced, the number of molds put up by each molder increased, and the cost of producing castings greatly reduced. Many of these cupolas are still in constant operation, and for 358 THE CUPOLA FURNACE. Fig. 72. MACKENZIE CUPOLA. SCIENTIFICALLY DESIGNED CUPOLAS. 359 short heats of one or two hours are probably the most eco- nomical melting ones now in use. In long heats the tendency of the cupola to bridge at the bosh is so great, that it melts slowly toward the end of a heat and is frequently difficult to dump, especially if it is a small one. We have had much experience in melting in these cupolas. and have found that slag and cinder adhere to the lining over the tuyeres, and become very hard and difficult to remove, and if care be not taken to remove them after every heat it soon builds out, as shown in Fig. 'ji, which reduces the melting capacity very much, and increases the tendency of the cupola to bridge and hang up. The lining should be kept as near the shape shown in Fig. ^2 as possible, and all building out 36o THE CUPOLA FURNACE. over the tuyeres and bellying out in the melting zone, as far as possible, prevented. Fig. 74. DR. OTTO GMELIN'S CUPOLA. In the illustration (Fig. 72) is shown the cupola pit, com- monly placed under cupolas when they are set very low for hand-ladle work. The outlet to the pit may be placed at the SCIENTIFICALLY DESIGNED CUPOLAS. 361 front, back, or side of the cupola, as found most convenient for removing the dump. DR. OTTO GMELIN S CUPOLA. The cupola shown in Fig. 74 was invented by Dr. Otto Gmelin, of Buda-Pesth, for smelting iron, copper, or other metals, and has during the last few years won ground in Austria- Hungary, and is now also being introduced in Germany. The illustration hardly requires any further explanation, considering the simplicity of the principle on which the furnace is constructed. Two concentric cylinders of boiler plates with Fig. 75. I A THE TOP PLATE. two annular spaces between them, closed at the bottom, and open at the top, are placed on a foundation ring of brickwork. Cold water enters the annular space at the bottom, and the warmed water flows off below the upper edge of the cylinders. The interior of the inner boiler-plate cylinder is, says Engi- 7ieering, made rough, and is covered with fire-clay. The cir- cular space between the two cylinders is covered over by a cast-iron plate which lies loosely on the top of the two cylin- ders. Two circular grooves in the cast-iron top plate maintain the two cylinders at the correct distance from each other. The outlet of the metal and of the slag takes place through 362 THE CUPOLA FURNACE. tubular boiler-plate connections passing through the water space and attached to the inner and outer cylinders. The con- struction has lately been considerably simplified and strength- ened by making the inner furnace cylinder of a welded tube, with tubes for air inlets welded on all in one piece. The novelty of the above construction consists chiefly in the cooling of the smelting furnace by water without using an air- tight water space. The inner cylinder can expand and con- tract without any resistance as the temperature in the furnace changes, and the consequence is that repairs are hardly ever required. The first furnace built upon this principle has now been at work daily for the last 2j^ years without ever having required any repairs to the boiler plates of the cylinders. The smelting operations can therefore also be kept up for any length of time without interruption. The energetic cooling of the inner smelting cylmder, which takes place with this system of furnace, is also stated to afford advantages as regards the sav- ing of fuel (equal to from 6 to 8 per cent.) and the decrease of burnt metal, as well as the good and equal quality of the castings. The above illustrations and description of Dr. Otto Gmelin's cupola are taken from a foreign engineering journal, and are here given to show what is being done in the way of protecting cupola linings with water. This theory has been a hobby of a number of founders we have met, and it has often been tried in this country and in a variety of ways, with but limited success. In one instance we recall to mind, gas pipe was closely coiled around the cupola at the melting zone, and covered with daubing one or more inches thick, and water forced through the coil when the cupola was in blast. In another, a tank constructed of boiler plate was placed around the inside of the cupola at the melting zone, and pro- tected by daubing. In both of these experiments it was found difificult to keep the pipes and tank filled with water, as the heat was so intense that water was driven from them very rapidly after melting began, and in one of them the bottom had to be SCIENTIFICALLY DESIGNED CUPOLAS. 363 dropped for fear of collapse of the tank and caisson. But this objectionable feature may readily be overcome by making the tank large and the inlet and outlet ample for a supply of cold water, which was not the case in this instance. The doctor appears to have solved this problem by extend- ing the water space from the bottom to top of cupola, giving a larger body of water to be heated than in the tests referred to. But even when this is done the water space must be large and the supply admitted at the bottom abundant, or every drop of water will be forced from the water space by the heat. The experiment referred to, while not perfectly satisfactory, so far as keeping the lining cool with water, was sufficiently so to convince the advocates of this theory in each case that noth- ing could be gained by protecting a lining in this way ; for they found by cooling the lining at the melting zone the melt- ing capacity of their cupola was reduced and more time was required to melt their heat and probably more fuel was con- sumed. While this cupola may be a success in foreign coun- tries, where slow melting is done, it would hardly prove a suc- cess in this country with our present desire for rapid melting, and is not likely here to come into use. As for the saving of fuel and improved quality of iron, all new cupolas effect these results, and they require no further consideration. PEVIE CUPOLA. In Fig. "jQ is seen the Pevie cupola, designed by Mr. Pevie, a practical foundryman of Lowell, Mass. The small cupolas, 18 to 24 inches, of this design are built square, with square corners in the lining, and larger ones are made oblong with square corners and 24 to 30 inches wide inside the lining, and any increase in the melting capacity of the cupola desired is obtained by increasing the length of the cupola in place of increasing the diameter, as is done with the round cupolas. Blast is supplied on two sides from an inner air chamber, through a vertical slot tuyere extending the full length of the sides of the cupola. 364 THE CUPOLA FURNACE. Fig. 76. J I PEVIE CUPOLA. SCIENTIFICALLY DESIGNED CUPOLAS. 365 The object of Mr. Fevie in constructing a cupola upon this plan was to supply an equal amount of blast to all parts of the stock and to produce even melting. This theory was correct, for blast was certainly more evenly distributed to the stock than with the small round tuyere then commonly used, and we saw excellent melting done in cupolas of this construction in the foundry of Pevie Sons, in a small town in Maine (the name of which is forgotten), which we visited some twenty years since. But in cupola construction an even distribution of blast is not the only matter of importance to be considered ; for if it bridges and clogs up, the blast cannot do its work, no matter how evenly it may be distributed by tuyeres or by the construction of a cu- pola, and the peculiar construction of this cupola made the ten- dency to bridge very great. It was only by careful management that it could in long heats be prevented from bridging, when the lining was kept in its original shape, and for this reason it never came into general use. We know of only three of them at the present time in operation, one at Smithville, N. J., and two at Corry, Pa., and the shape of the linings in these cupolas has been greatly altered from their original form. Stewart's cupola. In Fig. '/J is seen a sectional view of a cupola in use at the Stewart Iron Works, Glasgow, Scotland. This cupola, which is one of large diameter, is boshed to throw the blast more to the center of the stock and reduce the amount of fuel required for a bed. Blast is supplied from a belt air-chamber extending around the cupola, through a row of tuyeres passing horizontally through the lining and a second row placed above and between the tuyeres of the first row and pointing downwards, as shown in the illustration. The object of this second row of tuyeres is to increase the depth of the melting zone and increase the melting capacity of the cupola per hour. Attached to the top of the air-chamber at intervals of about two feet, is placed a vertical gas-pipe of two inches diameter, and from this pipe four branches of one-inch pipe lead into the cupola, about 366 THE CUPOLA FURNACE. Fig. 77. STEWART'S CUPOLA. SCIENTIFICALLY DESIGNED CUPOLAS. 367 twelve inches apart. The object of these pipes is to supply a sufficient amount of oxygen to the cupola above the melting zone to consume the escaping unconsumed gas, namely car- bonic oxide ( CO), above the melting zone, and utilize it in heating and preparing the iron for melting before entering the zone. The cupola melts very rapidly, and is said to be the best melting one in Glasgow. But it is very doubtful if the one- inch gas- pipe tuyeres contribute anything towards the rapid melting, for it is absurd to suppose that one-inch openings placed twelve inches apart vertically, and two or more feet apart around the cupola, would supply a sufficient amount of oxygen to fill a large cupola to such an extent as to ignite escaping carbonic oxide in the center of the cupola. While they might supply oxygen for combustion of carbonic oxide nea"- the lining, we do not think they would admit a sufficient amount to be of any practical value in melting, even if they admitted a volume of blast equal to their capacity when placed in the lin- ing. This they do not do, for they are frequently clogged by fuel or iron, filled with slag from melting of the lining, and as a lining burns away the ends of the pipes are heated and fre- quently collapse at the ends, and it is almost impossible to keep them open during a heat, or to open many of them after a heat is melted. The rapid melting in this cupola is probably due to the arrangement of the first and second rows of tuyeres and the shape given to the inside of the cupola, which is excellent for cupolas of large diameter. THE GREINER PATENT ECONOMICAL CUPOLA. In Fig. 78 is shown the Greiner cupola, for which the follow- ing claims are made : In placing the Greiner Patent Economical Cupola, before the foundrymen and steel manufacturers in this country, we have the advantage of the splendid results already obtained with this cupola in Europe, where more than three hundred are in daily use. The adoption of the Greiner system of melting iron there has met with the most satisfactory results. In no case has the sav- 368 THE CUPOLA FURNACE. ing of fuel been less than twenty per cent., and in some instan- ces it has reached forty and even fifty per cent. The novelty of the invention consists in a judicious admission of blast into the upper zones of a cupola, whereby the combus- FiG. 78. THE GREINER PATENT ECONOMICAL CUPOLA. tible gases are consumed within the cupola and the heat utilized to pre-heat the descending charges, thereby effecting a saving in the fuel necessary to melt the iron when it reaches the melt- ing zone. Considerably more space was given to this cupola in the first edition of this work, where it may be seen ; but as we do not know of a single one of them in operation in this country, we SCIENTIFICALLY DESIGNED CUPOLAS. 369 devote the space to more important matter. The same prin- ciple may be seen more fully illustrated in the sectional view of the Stewart Cupola (Fig. "JT). STEAM JET CUPOLAS. The arrangement of pipes of the Greiner cupola recalls to mind the arrangement of pipes, a variety of which we have seen, for admitting steam jets at various points to cupolas for the purpose of improving the melting or the quality of the iron. This mode of melting has been thoroughly tried in this country in years past and a number of patents have been taken out for it here and in Canada, none of which have ever come into general use, although great claims have been made for them both as to economy of fuel and improvement of quality of iron. The inventor of one of them, which we saw in opera- tion some twelve years ago, went so far as to claim he could from a cupola produce an iron having all the qualities of mal- leable iron. This device we found upon investigation to con- sist of putting a jet of steam into the cupola at the tuyeres with the blast, which only amounted to putting that amount of water into the cupola, which, so far as we could see, had no effect on the qualiy of iron, and certainly no malleable iron was pro- duced in the heat we saw melted. We made a series of experiments in melting in a cupola with steam with and without blast some twenty-five years ago. A detailed account of these experiments is not necessary, for they proved a complete failure so far as saving fuel, making hotter iron, or improving the quality of the iron ; although we were under the impression at the time that some improve- ments had been effected, but these, like many results obtained in experiments, were deceptive and due rather to careful manage- ment of the cupola than to any benefit derived from the steam. Since making these experiments we have met a number of men who have experimented in this direction, among them the late Thomas Glover, who, when foreman of the large foundry of Morris, Tasker & Co., made extensive experiments with steam 24 370 THE CUPOLA FURNACE. in their large cupolas, using wet and super-heated steam, and putting it into the cupola at the tuyeres and above and below the melting zone. Mr. Glover kept an accurate record of these experiments, a copy of which he ofifered to furnish for this work, but the experiments were made years ago, and when he came to look for the record it could not be found. That the results of these experiments were not satisfactory is shown by the fact that Morris, Tasker & Co. did not continue the use of steam in their cupolas, and when Mr. Glover engaged in busi- ness for himself, as the firm of Glover Bros., he did not apply steam to their cupolas. From what we have observed in melting with wet and super- heated steam we have concluded that the passing of steam into a cupola amounts only to the placing of a certain amount of water or moisture in it, and this may be accomplished in a more economical way than with steam. By placing a small water jet at each tuyere the water may be atomized and carried into the cupola with the blast, and by placing one or two gunny bags over the inlet of a blower, and keeping them wetted with water, moisture may be added to the blast and carried into the cupola. But probably the best way to accomplish this is to wet coke before charging. Years ago it was the common prac- tice of founders to let their coke lie out in the weather, and in dry weather to wet it with a few bucketfuls of water before charg- ing, upon the theory that wet coke made hotter iron than dry. But since the discovery by some one that about one-third more coke is required to smelt iron in a blast furnace on a wet day when the atmosphere is full of moisture, than on a dry day, this theory has been abandoned by founders and coke carefully housed. While this discovery may be correct in a blast furnace, which we very much doubt, we think that a careful" and prolonged test will demonstrate that the reverse is the case, and that more fuel is required on a dry day than a wet one. For a gas may be made from water having a sufificient number of heat- producing units to melt iron. This being the case, why should SCIENTIFICALLY DESIGNED CUPOLAS. 37 1 not a blast saturated with moisture produce a greater amount of heat than a dry one? But whether or not this theory be correct as regards a blast furnace, it is certainly not so in a cupola, for no founder ever thinks of placing more fuel in his cupola on a wet day than on a dry one, and always has hotter iron on a wet, murky or foggy day than on a dry, clear one, with the same amount of fuel. From our observation in the use of steam in a cupola, we are of the opinion that, as good results may be obtained from steam generated in a cupola in any of the ways outlined as from steam generated in a boiler and conveyed to it by pipes, and that no great benefit can be derived from steam in either way. JUMBO CUPOLA. In the accompanying illustration. Fig. 79, is shown a sectional elevation of the large cupola known as Jumbo, in use in the foundry at Abendroth Bros., Port Chester, N. Y., to melt iron for stove plate, sinks, plummers' fittings, soil pipe and other light castings, all requiring very hot fluid iron. The cupola, which was constructed for the purpose of melting all the iron required for their large foundry in one cupola, is of the following dimen- sions : Diameter of shell at bottom to height of 24 inches, 7 feet 6 inches ; diameter in body of cupola, 9 feet ; taper from large to small diameter, 5 feet 6 inches long; diameter of stack, 6 feet; taper from cupola to stack, 6 feet long ; height from bottom plate to bottom of taper to stack, 20 feet; height to bottom of charging doors, 18 feet; two charging doors placed in cupola on opposite sides. Wind box inside the shell extending around the cupola, 5 feet 6 inches by 9 inches wide. Height of tuyeres, first row, 24 inches; second row, 36 inches; third row, 48 inches. Size of tuyeres, first row, 8X5 inches ; second row, 6X4 inches; third row, 2X2 inches. Number of tuyeres in each row, 8 ; total number of tuyeres, 24. Slag hole, 17 inches above iron bottom, 1 1 inches above sand bottom. Two tap holes. Lining, 18 inches thick; over air belt, 9 inches. Di- ameter of cupola at bottom, inside the lining, 4 feet 6 inches. Diameter above taper, 6 feet. Cupola supplied with blast by No. 6 Baker blower. It is charged as indicated in the table as follows: 11^ THE CUl'OLA FURNACE. 1 iZ > ' o a o J3 eS tn -« i -o Pi \ 3 O O o- o o Pi : 1 8 • •^ •J33UOIJ Xapunoj : : o o o o : o o o o . . o o o o . • ' '1 iJ o 3 IT) c32 z -oj^ : 1 1 1 : •• '• w H 1 "^ •|B)01 pUB c 3 lOOOOOOOOOOOOOOO c jiooooooocoooooolo 3 N) c 5, , q, q q, q q q q_ o o o ^, o_ o 1^ ^ O ;b spunoj f ' 1 :? ^ ! "' o j •dBJDS c )iOOOOOOOOOOOOOO,0 3 ^ o « > c ):ooooooooooooooo r "! Tl- puB sanjidg c ) oooooocoooooo" 1- t— 1 ! 1 ^ll z J 1 ' II o C 3 O C o 0$ c ) oooooooooooooo o •Xe •osj: e ) oooooooooooooo o q.q.oq.ooqo^^o^o^qqorf o ON M • 1 s " ^ |i • '"' y o U i: a Q c ~ .2 c 1 , ) 1 oooooooooooooo i o lU ^ , c )iOOOOOOOOOOOOOO ol S L> yj, -ojsi >J n 1 q o__ q_ o__ q o^ o^ o^ o^ q^ o_ o__ q ■* 1 q^ V H o ^ H '»'>^>^n>^>^t^J^>^<^t^i^i:^J!i ocT u» _ -" en >^ 3 E- -1 O — ' i 1 1 aj 1 , CQ < c > oooooooo . o o o p ^ N c ) oooooooo 1 o o 1 o ! o S •X2 -ON fj q o^ q o__ o^ o^ q q . o 00 ] 'o ] i- -t 1 e 1 z w fl b 1 8 6^ C ) oooooooooooooo o oooooooooooooo O ' n qqqqqqqqqqqqqoo ro| < •I -oj^ C ^ . ^ N • H ^i c OOOOOOOOOOOOOO O •ajloD spanoj g OOOOOCOOOOOUO"! "^ a; 1 (1 I a^ c ir)u^Low^"->"^uiOOOOO • ui C 00 "1 'IBOD spunoj c NNtSNNNNOOOOO • iHwi-i«»i-iw«NPOrorOw • '^ «=» ^ ^ « ; •<*■ "- 4 ^ ' 1 \ • B 3> ■ . i ' • o 00 I 1 ; " • ro . * " o i?i c I • J= ' • : 6 Xi « s ;z^ f eac on . • O "o 2 = ~ ; 2 1 a. o 1-1 1. ^ r^ D "^ t ■o X •o x- 13 ■o -u -r "C "D XJ ■O -U) 1 P o O cj 13 O « ^ 4*CJDVDl'l>Ul>'L»UttJ« c ;S o \\ \Sl\fl5\j^\M\p0\CO\61^fl3\0O\Ol\^\o5\M\^ .£ u-1 uovO t~.00 ON— M Tt-vO t^O\i-" N rJ-u-it^ONO M m UM^OO O 00 £ 1) J2 1°^^ 00 .2-*r " Q °-S w ^ Pi, t3.S-T3 1^^ "^ .2 -t; ^\co \M\co \eo\co ~\^\j)i N^Xjf \:rti ViJiN^N ►,«H,„.,.,>,P4NNNNNNro<~Oro rOOO ro •h\ M\C»!\TH\rt\ M\e<5\rH\UY\ M\rt\rH\"0\ ^\ M\ W\t-1\i-I\ •^ \r, i/^o r^oo O ►" N -^ Lo r-~oO a\ -" n tt "-> t^oo On — fs •* O fO S P^ 1 •»- Q V.I V u n 2 a 43 \co\jji\co\iM\Tj«\eo\i)\ce-,M\e(\Tji\^N -i M -^ U-) t-.00 On O N O t^ •^ rj- ir^ u-inO t^OO O ►< ^^ <~0 u-,\D t^ On O ►• N ■^ u-ivO i^ On O O « i-.i-i«.-i-ii-,«i-iMMCSNNMP Wl J3 CO ti c c t.ri 4_» V B (4 Q \C0\CO\!j.\C0 ro "I- rj- w-)>0 r-OO On O -- fO t1- "-.vO t^ On O — N ro ttnO I-^OO O "^ m ro -^ u-i u^vO t^oo O 1-1 N fO ■* lonO t^ t-^ On O M ^O ■^ ltivC O On »-»-«i_«««i_i_ii-iMri 261.58 6 28274 12K 117.85 i^li 268.80 6K 30.679 1 21^^ 122.71 1 '8% 276,11 6>^ 33-183 12% 127.67 19 283-52 6% 35-784 13 132-73 19% 291.03 7 38-484 I3M 137-88 19 H 298.64 IV^ 41.282 13^2^ 143- 1? i 19% 306.35 7>2 44.178 13% 148.48 20 314.16 IYa 47-173 14 15393 8 50.265 I4>i 159.48 BLAST PIPES AND BLAST. 399 In connecting blast pipes direct with tuyeres, either by long branch pipes from the main pipe or short ones from a belt air chamber not attached to cupola shell, care should be taken to have as few joints or connections in the pipes as possible, and every joint should be made in such a way that the jar made in chipping out andcharging the cupola will not cause the joints to leak after they have been in use a short time. In leading pipes out of an air chamber they cannot always be placed in line with the current of the blast, and must be filled from pres- sure of blast in the air chamber, but the connecting pipes may be shaped to guide the blast smoothly from the air chamber to its destination. In Fig. 83 is shown as perfect a connection of air chambers of this kind as can be made. In this illustration the belt pipe A A is placed up out of the way and of danger of being injured when making up or working the cupola, and the branch pipes to each tuyere are straight and smooth inside and the pipe is given a curve at the bottom to throw the blast into the tuyere without having the force of its current impaired, and the tuyeres are of a size to admit the full volume of blast from the pipe. Only two joints are required in connecting the air chamber with the cupola, and these are made in such a way that they may be securely bolted or riveted, and all leakage prevented. In contrast with the neat arrangement of pipes on this cupola is shown the other extreme of poor arrangement in illustration Figure 85. This is a section of a " perfect cupola" illustrated and described in T/ic Iron Age some years ago, and while other parts of the cupola may have been perfect, this part was cer- tainly very imperfect. The air chamber and its connecting pipes are made of cast iron. The connecting pipes are cast in three pieces, necessitating the making of four joints. The air box is cast in two pieces, requiring another joint; and a peep- hole and an opening for escape of slag and iron running into the tuyeres, is placed in the pipe, making in all seven joints and openings in each connection to be made and kept air-tight. The jar in working the cupola, together with the small explo- 400 THE CUPOLA FURNACE, sions of gas that frequently take place in cupolas and pipes^ Fig. 85. POOR ARRANGEMENT OF BLAST PIPES. would naturally tend to loosen many of these joints, and a large BLAST PIPES AND BLAST. 4OI amount of blast would be lost through leakage of joints. The many joints make more or less roughness in the pipes, thus im- peding the blast. The turn in the pipe for connection with the tuyere is square and the course of the current of air is abruptly changed, and the tuyere is entirely too small to admit the full volume of blast from the pipe to the cupola, and only by a heavy pressure of blast could the air be forced into the cupola in sufficient quantities to do good melting. In Fig. 83 is shown another way of connecting a belt air- chamber with the tuyeres. In this case the pipe is made of galvanized iron, and the tuyere boxes are made of cast-iron and are large, giving abundant room for changing the direction of the blast current. Only two joints are made in connecting the air-chamber with the cupola ; beside these joints, the end of the tuyere box is closed with a large door, the full size of the box, and a peep-hole is placed in the door, making two more open- ings to be kept air-tight. Many cupolas are in use having their blast connections arranged in this way, and while the arrange- ment is good, it is not perfect, and a great deal of blast is lost through leakage of joints — the principal loss occurring around the large door and at the joint connecting the galvan- ized iron pipe with the cast-iron tuyere box. The very best way of connecting blast pipes with cupola tuyeres is by means of a belt air-chamber riveted to the cupola casting, as shown in Figs. 28, 30 and 31, or by an inside air- chamber, as shown in Figs, "jz and "j^. In either case the air- chamber is riveted to the cupola shell and the joint made per- fectly air-tight, and in case of jar to the cupola, the air-chamber being part of the cupola, oscillates with it, and the jar in chip- ping out and charging does not loosen the joint and cause leak- age of blast. The blast pipes may also be securely riveted or bolted to the air-chamber and a perfectly tight joint made. In constructing cupolas in this way, care should be taken to make the air-chamber of a sufficient size to admit of a free circulation of blast and supply all the tuyeres with an adequate amount for good melting. When the air chamber is small, the blast-pipe 26 402 THE CUPOLA FURNACE. should be connected with it on each side of the cupola, and on the side or top as found most convenient. When the chamber is large and there is an abundance of room for the escape of blast from the pipe, one pipe is sufificient and it may be connected on the side or top. When attached on the side it should be placed in line with the circle of the cupola as shown in Fig. 34, to cause the current of blast to circulate around the cupola and facilitate its escape from the pipe. When Fig. 86. BLOWER PLACED NEAR CUPOLA. the current of blast is thrown directly against the cupola casing or bottom of the chamber in a narrow air-chamber, the mouth of the pipe should be enlarged, to facilitate the escape of blast into the chamber ; for cupolas of this construction may be made a complete failure by failing to provide a sufficient space at the end of the pipe for escape of blast into the air-chamber, when the chamber is of a sufificient size to supply the cupola. Con- nections with the inner air-chambers of limited capacity should BLAST PIPES AND BLAST. 403 be made on each side by means of an air or tuyere box placed outside, as shown in Fig. 6, and the pipe connected on top to equaHze the volume of blast supplied to each tuyere. Long blast pipes often cause poor melting, from the volume of blast delivered to a cupola being reduced by friction in the pipes, and in all cases the blower should be placed as near the cupola as possible, in Fig. 86 is shown a very neat arrange- ment in placing a blower near a cupola and at the same time having it up out of the way of removing molten iron or the dump from the cupola, and the space under it may be utilized for storing ladles, etc. In this illustration is also shown a very perfect manner of connecting the main pipe with an air cham- ber. The pipe is divided into two branches of equal size in line with the current of blast from the blower, and connected with the air chamber on each side by curved pipes arranged in such a way as not to check the current of air as it passes through the pipe. PLACING A BLOWER. A blower should always be placed at as near a point to a cupola as is consistent with the arrangement of the foundry- plant, and it should be l.iid upon a good, solid foundation, and securely bolted to prevent jarring, as there is nothing that wrecks a blower so quickly as a continual jar when running at high speed. In Fig. 86 is shown a convenient way of placing a blower near a cupola, and at the same time having it out of the way. But when so placed, the blower should be laid upon a solid frame-work of heavy timber, and securely bolted down to prevent jarring when running. It should also be boxed in to prevent air being drawn in from the foundry, and have an open- ing provided for supplying air from the outside, for air drawn from a foundry when casting and shaking-out are taking place is filled with dust and steam, which are very injurious to a blower and pipes. A blower should never for the same reason be placed in a cupola-room or a scratch room in which castings are cleaned ; 404 THE CUPOLA FURNACE. for it is impossible to exclude dust from the bearings when so placed, and when a bearing once begins to cut, it makes room for a greater amount of dust, and cuts out very rapidly in blow- ers run at high speed. Dust and steam also corrode and de- stroy blast wheels which are inside the blower and out of sight, and a blast wheel may be almost entirely destroyed and not discovered until it is found the cupola is receiving no blast. To prevent a blower from being destroyed in this way, and insure a proper volume of blast for a cupola, the blower should be placed in a clean, dry room and supplied with pure air from the outside. If it cannot be so placed near a cupola, it had better be placed at some distance, in which case the blast-pipe must be enlarged in proportion to its length, as described else- where. When a blower is placed in a closed room, windows should be opened to adrnit air when it is running, and when the air about the room is filled with dust, a pipe or box for supplying pure air should be run off to some distance from the blower and the room kept tightly closed. BLAST GATES. These devices are especially designed lor opening and clos- ing blast pipes, such as are employed for conveying air be- tween blowers and cupolas. There are several different de- signs of blast gate?, but the one shown in Fig. 87 is the one most commonly used by foundrymen. They aie manufactured and kept in stock by all the leading manufacturers of blowers, and cost from one dollar upwards, according to size of blast pipe. The employment of the blast gate places the volume of blast delivered to a cupola under control of the melt-er, which feature is frequently very important in the management of cupolas in melting iron for special work, or in case of accident or delay in pouring. In foundries in which the facilities for handling molten metal are limited and melting must at times be retarded, to facilitate its removal from the cupola as fast as melted, and in foundries where the amount of iron required to BLAST PIPES AND BLAST. 405 be melted per hour is limited by the number of molds or chills employed, from which castings are removed and the molds re- filled, it is very important that the blast should be under con- trol of the melter. In such foundries the cupolas are general!}' of small diameter and frequently kept in blast for a number of hours at a time, and it is often desired to increase the volume of blast to liven up the iron, and decrease it to reduce the amount melted in a given time. The blast gate places the blast under control of the melter and enables him to increase or diminish its volume as deemed Fig. 87. BLAST GATE. necessary to obtain the best results in melting. They are often of value in regular cupola practice to reduce the volume of blast and retard melting for a few minutes while pouring a large piece of work, in foundries where the facilities for hand- ling large quantities of molten iron are limited, and the speed of blower cannot be reduced without reducing the speed of machinery in other parts of the works or stopping the blower entirely, which is not good practice after a cupola has been in blast for some time. 406 THE CUPOLA FURNACE. The gate is also a safeguard against gas explosions, which often occur from the accumulation of gas in pipes during the temporary stoppage of the blower. The gate should always be placed in the pipe near the cupola, and closed before stop- ping the blower and not opened until it is again started up. EXPLOSIONS IN BLAST PIPES. Violent explosions frequently take place in cupola blast pipes,, tearing them asunder from end to end. These explosions are due to the escape of gas from the cupola into the pipes during a temporary stoppage of the blower in the course of a heat. The explosion is caused by the gas being ignited when the pipe becomes over-charged, or the instant the blower is started and the gas is forced back into the cupola. Such explosions gen- erally take place in pipes placed high or arranged in such a way as to have a draught toward the blower. But they may occur in any pipe if the cupola is well filled when a stoppage takes place and the blower is stopped for a great length of time. Such explosions may be prevented by closing the blast-gate if placed near the cupola, or by opening the tuyere doors in front of each tuyere and admitting air freely to the pipe. Such precaution should always be taken the instant the blast is stopped, as a pipe may be exploded after only a few minutes' stoppage of the blower, and men may be injured or the blower destroyed by the explosion. BLAST GAUGES. A number of air or blast gauges have been designed and placed upon the market for determining the pressure of blast in cupola blast pipes and air-chambers. These gauges are of a variety of design, and are known as steel spring, water and mercury gauges. They are connected with a blast pipe or air- chamber by means of a short piece of gas-pipe or a piece of small rubber hose, through which the air is admitted to the gauge. The pressure of blast is indicated by a face dial and BLAST PIPES AND BLAST. 407 hand on the spring gauge, and by the graduated glass tube of the water and mercury gauges, pressure being shown up to two pounds, in fractions of an ounce. These gauges, when in good order, indicate very accurately the pressure of blast on a cu- pola, and when tuyeres and pipes are properly arranged, show to some extent the resistance offered to the free escape of blast from the pipe and the condition of the cupola in melting. But they do not indicate the number of cubic feet of air that pass into a cupola in any given length of time, and a gauge may show a pressure of six or eight ounces when scarcely a cubic foot of air is passing into a cupola per minute. With a pressure blower these gauges show a gradual increase of pressure in the pipe when a cupola is clogging up, and may enable a foundryman to prevent bursting of the pipe ; but with a non-positive blower they show nothing that is of any value to a foundryman in melting, so far as we have been able to learn. The volume of blast is what does the work in a cupola, and not the pressure ; and a high pressure of blast does not always indi- cate a large volume of blast, but rather the reverse, for little if any pressure can be shown on a gauge when blast escapes freely from a pipe. We have seen two cupolas of the same diameter, one melting with a two-ounce pressure of blast and the other with a six- ounce pressure, and the cupola with the low pressure doing the best melting. This was simply because with the low pressure the air was escaping from the pipe into the cupola and with the high pressure it was not, and the high pressure was wholly due to the smallness of the tuyeres which prevented the free escape of blast from the pipe mto the cupola. A definite number of cubic feet of air has been determined by accurate experiments to be required to melt a ton of iron in a cupola, and an air-gauge to be of any value in melting must in- dicate the number of cubic feet of air that actually enter a cupola at the tuyeres. We have at the present time no such gauge, and in the absence of such a gauge the foundryman's best guide as to the number of cubic feet of air supplied to his 40S THE CUPOLA FURNACE. cupola is the tables furnished by all manufacturers of standard blowers, giving the number of revolutions at which their blowers should be run, and the number of cubic feet of air de- livered at each revolution. From these tables a foundryman may figure out the exact number of cubic feet of air his cupola receives, provided there is no leakage of air from pipes or tuyeres and the tuyeres are of a size that will permit the air to enter the cupola freely. BLAST IN MELTING. , A cupola furnace requires a large volume of air to produce a thorough and rapid combustion of fuel in the melting of iron or other metals in the furnace. Numerous means have been devised for supplying the required amount of air, among them the draught of a high chimney or stack, and the creating of a vacuum in the cupola by means of a steam jet, placed in a con- tracted outlet of a cupola as shown in Figs, tg and 70. These means of supplying air are a success in cupolas of small diam- eter and limited height, but even in these cupolas the volume of air that can be drawn in is not sufficient to produce rapid melting, and it is doubtful if iron could be melted at all in a cupola of large diameter and of a proper height to do econom- ical melting, by either of these means of supplying air. Owing to the peculiar construction of a cupola furnace and the manner of melting, the free passage of air through it is restricted by the iron and fuel required ; and rapid melting can only be done when air for the combustion of the fuel is supplied in a large volume, which can only be by a forced blast. A number of machines have been devised for supplying this blast, among the earliest of which were the leather bellows, trompe or water blast, chain blast, cogniardelle or water-cylin- der blast, cylinder or piston blower. These have, as a rule, given away to the more modern fan blower and rotary positive blast blower, a number of which will be described later on. The relative merits of a positive and non-positive blast, is a very much disputed question. It is claimed by many that BLAST PIPES AND BLAST. 409 with a positive blast a definite amount of air is supplied to a cupola per minute or per hour, while with a non-positive blower or fan there is no certainty as to the amount of air the cupola will receive. This is very true, for a cupola certainly does not receive the same amount of air from a fan blower when the tuyeres and cupola are beginning to clog as it does from a positive blower when there is no slipping of the belts. But is it advisable to supply a cupola with as large a volume of blast when in this condition as when working open and free? Does not the large volume of blast have a chilling effect upon the semi-fluid mass of cinder and slag, and tend to promote clog- ging about the tuyeres while keeping it open above the tuyeres ; while blast from a non-positive blower would percolate through small openings in the mass, and be more effective than a large volume of blast from a positive blower forming large openings in it through which it escaped into the cupola? These are questions we have frequently tried to solve b)' actual test; but it is so difftcult to find two cupolas of the same dimensions melting the same sized heats for the same class of woik, one with a positive and the other with a non-positive blast, that we have never been able to test the matter. We have melted iron with nearly all the blowers now in use and with a number of the old-style ones, and think there is more in the management of a cupola than there is in a positive or non- positive blast. Good melting maybe done with either of them, when the cupola is properly managed, and it cannot be done wiih either of them when the cupola is not properly managed. Until the management of cupolas in every-day practice is re- duced to more of a system than at present, it will be impossible to determine any practical advantage in favor of either blower over the other. So far as we are concerned, we have no prefer- ence in blowers, but make it a rule to charge a cupola more openly when melting with a non-positive blast, for the reason that stock may be packed so closely in a high cupola that the volume of blast that is permitted to enter at the tuyeres may not be reduced by preventing its escape through the stock. 4IO THE CUPOLA FURNACE. The amount of air that is required for combustion of the fuel in melting a ton of iron has been determined by accurate ex- periments to be about 30,000 cubic feet, in a properly con- structed cupola in which the air was all utilized in combustion of the fuel. This amount of air if reduced to a solid would weigh about 24,000 lbs., or more than the combined weight of the iron and fuel required to melt it. In a cupola melting ten tons per hour, 300,000 cubic feet of air must be delivered to the cupola per hour to do the work. It will thus be seen, that a very large volume of blast is required in the melting of 10 tons of iron. To deliver this amount of air to a cupola from a blower that is capable of producing it in the shape of a blast, the blast pipes must be arranged in such a way that the velocity of the air is not impeded by the pipes; and the tuyeres must be of a size to admit the air freely to the cupola. This is not always the case, for we have seen many cupolas in which the combined tuyere area was not more than one-half that of the blower outlet. The object in making the tuyere area so small was to put the air into the cupola with a force that would drive it to the center of the stock. This was the theory of melting in the old cupolas with small tu)"eres, but this was wrong, for air cannot be driven through fuel in front of a tuyere, as an iron bar could be forced through it, even with a positive blast; and when the air strikes the fuel it cannot pass through it, but escapes through the crevices between the pieces of fuel. These crevices may change its direction entirely, and the same force that drives it into the cupula impels it in the direction taken,, which will be the readiest means of escape, and is more liable to be up along the lining than toward the center of the cupola. For, as a rule, stock does not pack so close near the lining as toward the center, and the means taken to prevent the escape of blast around the lining is the very thing that causes it to escape in that way. Since blast cannot be driven through fuel to the center of a cupola and can only escape from the tuyeres through the crevices between the pieces of fuel, the only way to force it to the center of a cupola is to supply a sufficient volume BLAST PIPES AND BLAST. 411 of blast to fill all of the crevices between the pieces of fuel. This can only be done by discarding the small tuyeres and using a tuyere that will admit blast freely to a cupola. In placing tuyeres in a cupola, it must be remembered that the outlet area of a tuyere is governed by the number of crev- ices between the pieces of fuel in front of the tuyere through which the blast may escape through the tuyere. With small tuyeres a large piece of fuel may settle in front of the tuyere in such a way that its outlet is not equal to one one-hun- dreth part of the tuyere area, in which case the tuyere is ren- dered useless, and may remain useless throughout the heat. P'or these reasons small tuyeres should never be placed in a cupola. For small cupolas we should recommend the trian- gular tuyere, Fig. 14, for the reason that it tends to prevent bridging, and its shape is such that it is less liable to be closed by a large piece of fuel than a round tuyere of equal area. The vertical slot tuyeres, Figs. 10 and 1 1, are also for the same reason good tuyeres for small cupolas. , For large cupolas we think the expanding tuyere, Fig. 3, is the best, and if we were constructing a large cupola we should use this tuyere in preference to any other, and make the outlet at least double the size of the inlet, and should place the tujeres so close together that the outlets would not be more than six or eight inches apart. This would practically give a sheet blast, and distribute air evenly to the stock all around the cupola. The width of the tuyere can be made to correspond with the diameter of cupola, and may be from three to six inches, and should be of a size that will permit blast freely to enter the cupola. Parties who have been melting with small tuyeres and put in large ones upon this plan must change their bed and charges to suit the tuyeres, for this arrangement of tuyeres would probably be a complete failure in a cupola charged in the same way as when not more than one-fourth of the blast supplied by the blower entered the cupola. The largest cupolas in which air can be forced to the center from side tuyeres with good results would appear from actual 412 THE CUPOLA FURNACE. test to be from four and a half to five feet. Larger cupolas than this have been constructed, and are now in use, but they do not melt so rapidly in proportion to their size as those of a smaller diameter. To illustrate this, we might cite the Jumbo Cupola of Abendroth Bros., Port Chester, N. Y., already de- scribed, in which the diameter at the tuyeres is 54 inches, and above the bosh 72 inches, in which 15 tons of iron have been melted per hour for stove-plate and other light castings. The Carnegie Steel Works, Homestead, Pa., have cupolas of seven and one-half feet diameter at the tuyeres and ten feet diameter above the bosh, in which the best melting per hour is only fourteen tons. The area of this cupola at the tuyeres is almost three times that of Abendroth's cupola, yet the amount of iron melted per hour is actually less than that of the smaller cupola. Tuyeres have been arranged in different ways in this large cupola, and from one to four rows used, yet the melting was not in proportion to the size of cupola. This would seem to indicate that the cupola was not properly supplied with blast near the center, and the melting done in the center was caused principally by the heat around it; which is probably the case, for the cupola is kept in blast night and day, for six days, and melting must take place in the center, or the cupola would chill up. There are many cupolas of sixty inches diameter at the tuyeres in use in which good melting is done, but this would seem to be the limit at which good melting takes place in a cupola supplied with blast from side tuyeres, for above this diameter the rapidity of melting does not increase in proportion to the increase in size of cupola. There has been considerable experimenting done during the past two or three years with a center blast tuyere for admitting blast to the center of a cupola through the bottom. We have had no practical experience with this kind of tuyere for the last twenty-five years, when we placed one in a small cupola with side tuyeres and found no advantage in it; probably for the reason that a sufificient quantity of air for an even combustion BLAST PIPES AND BLAST. 413 of the fuel was supplied to the center of the cupola from the side tuyeres. During the past few years, we have visited a number of foun- dries in which the center blast was being tried, but in every case the tuyere was out of order or not in use at the time of our visit. The great objection to this tuyere seems to be its liability to be filled with iron or slag and rendered useless. Should this objectionable feature be overcome, it would cer- tainly be a decided advantage in melting in cupolas of large diameter in connection with side tuyeres. In cupolas of small diameter with side tuyeres, we do not think a center blast would increase the melting capacity of a cupola, for the reason that air can be forced to the center of a small cupola from side tuyeres, when properly arranged and of a proper size. With a center blast alone, it is claimed that considerable sav- ing is effected in lining and fuel. It is reasonable to suppose that a saving in lining might be effected by a center blast; for the most intense heat that is created by the blast is transferred from near the lining to the center of the cupola, and the tend- ency to bridge is greatly reduced. As to the saving of fuel, there never was a new tuyere that did not " save fuel," and there have been hundreds of them, but consumption of cupola- fuel is still too large. CHAPTER XXV. BLOWERS. To describe and illustrate all the blowing apparatus designed for furnishing blast for cupolas would require a larger volume than this one is designed to be, and would be of little practical value, as founders are not looking for obsolete but up-to-date machinery. We shall therefore confine ourselves to a descrip- tion of a few and most improved blowers. The blowers used for this purpose at the present time are confined almost exclusively to two types, viz.. Rotary Pressure Blowers and Fail Blowers. Each of these types has its advo- cates, and both are extensively used in supplying cupola blast. That they may be employed for this purpose is clearly demon- strated by the many hundreds of each type now in use. The question of superiority of one type over the other for furnishing cupola blast is one that has been extensively dis- cussed, and for which extravagant claims have been made by the manufacturers of each, and proved by them to their own satisfaction and in many cases to the satisfaction of their patrons ; and where such claims can be proved by the manu- facturers of each type, there must be some good points in each. We have melted iron in all the various styles of cupolas now in use, and in many of the old styles that have gone out of use with both these types of blowers, and have also seen a good deal of melting done with them, and are of the opinion that as fast and economical melting can be done with one type as with the other, when a cupola is properly managed ; and good melting cannot be done with either one of them if a cupola is not properly managed. It is just as well to have the blast shut ofT by the settling of stack and clogging of the cupola, as is claimed to occur with a fan blower, as it is to force blast (414) BLOWERS. 415 into a cupola when in this condition, as can be done with a pressure blower. For in such cases, the blower if of a proper size is not responsible for this condition of the cupola, and when in this condition good melting cannot be done with either blower. The selection of a blower is therefore a matter to be decided by each founder, and the points to be considered are, which is the most economical blower under the conditions in which it is to be placed. THE GRKEN PATENTED POSniVE FRPSSURE BLOWER. This is a blower of a new design recently placed upon the market by the Wilbraham-Baker Blower Co., to take the place of the Baker blower, for many years manufactured by them. The new blower is said to be a great impro\ement upon the Baker blower, which for many ) ears was one of the best in use for foundry cupoLis. We regret that the descriptive matter of the Green Blower was not ready in time for this work, and we are unable to give a detailed description of its construction and advantages for cupola work. CONNFRSVILLE CYCLOmAL BLOWER. The Connersville Positive Pressure Blower is one of the latest designs of blower, and has only been manufactured for a few years. A description of it is taken from the excellent circular, which is well worth reading by those contemplating the pur- chase of pressure blowers, and is as follows: The cycloidal curves, their nature, peculiarities and possi- bilities, have always b( en an attractive study, not only to the theoretically inclined, but more particularly to those interested in the many important applications of these curves in practical mechanics. The especial value of combining the epi- and hypocycloids to form the contact sui faces of impellers for rotary blowers, gas exhausters and pumps has long been recognized, and many attempts have been made to utilize them in that con- nection, but in vain. While conceded to give the theoretically correct form to a revolver or impeller, it came to be regarded 41 6 THE CUPOLA FURNACE. as impossible to produce such surfaces by machinery with suffi- cient accuracy to admit of their use in practice with anj' degree of satisfaction. It remained for us to demonstrate that it could be done, and in a highly successful manner as well. Fig. 88 is an illustration showing a cross section of our new cycloidal blower, and particularly of the revolvers or impellers, their form, relation to each other, and to the surrounding case. A glance only is required to discern the superiority of this method of construction over all others. The vital part of every machine of this class is the impeller, Fig. 88. SECTIONAL VIEW OF CONNERSVILLE CYLLOIDAL BLOWER. as on it depends economy of operation and efficiency in results. That we have the ideal form for an operating part is self-evident. It will be noted that there are two impellers only, and each is planed on cycloidal lines with mathematical accuracy. Now, it is one of the well-known peculiarities of the epicycloidal and hypo-cycloidal curves, when workeil together as in our machines, that there is a constantly progressive point of contact between the impellers. As a result of this regular advance of the point of contact, the air is driven steadily forward, producing a smooth discharge that is conducive to the highest economy. The advantage of this arrangement over the use of arcs of circles to approximate contact curves is very great, as it is a BLOWERS. ' 417 well-demonstrated fact that circular arcs whose centers are not coincident with the centers of revolution can not keep practical contact through an angle of more than four or five degrees. On the contrary, the contact does not progress continuously, but jumps from one point to another across intervening recesses as the impellers revolve, leaving pockets in which the air is alter- nately compressed and expanded, producing undesirable pulsa- tions in the blast, a waste of power, and necessitating two points of contact at one time in four positions in each revolution. Another advantage of the cycloidal form is that, at the point of contact, a convex surface is always opposed to a concave surface; that is, the epi-cycloidal part of one impeller works with the hypo- cycloidal part of the opposite impeller. The consequence of this is to produce a long contact or distance through which the driven air must travel to get back between the impellers, instead of the short contact that results when two convex surfaces oppose each other, as is the case in other machines of this character. Attention has previously been directed to the fact that the point of contact between the impellers continuously progresses ; indeed, the path it describes is a circle. One result of this con- tinuously-progressive contact, as before mentioned, is a smooth, reliable blast. Another is, as has also been noted, the absence of any pockets or cavities in which air can be gathered, com- pressed and then discharged back toward the inlet side of the machine, thereby entailing a waste of power and shortening the life of the blower by subjecting the impellers, shaft and gears to a needless shock, strain and wear. Furthermore, the impellers can be in contact only at one point at the same instant — in no position is it possible for them to touch each other at two points at once ; hence, there are no shoulders to knock together when the speed is more than nominal. On account, also, of there being no popping due to the ex- pansion of air when released from the pockets in which it has been caught and compressed, and no pounding of the impellers together, that disagreeable din and vibration usually associated 27 41 8 ' THE CUPOLA FURNACE. with machines of this class is eHminated, and our blowers run with practically no noise. This is a feature that will commend itself to parties having had experience with other pressure blowers. Another point contributing to the evenness and uniformity of the di>charge is the fact that the extremities of the impellers are curved. Thus, as they sweep past the outlet, there is a gradual equalization of the pressure instead of a sudden shock, such as results from the passage of two sharp edges, which shocks are sodi^trimental to all working parts, as has been noted. From what has been stated, we scarcely need to add that the machme is positive in iis action. All the air that enters the blower is inclosed by the impellers, forced forward and dis- charged through the outlet pipe. The leakage is insignificant, and there is no compressed air allowed to escape backward. Hence, all the power applied to the machine is used for the purpose intended — the maintenance of an even blast — and none of it is wasted on needless work. Furthermore, as the contact between the impellers and the surrounding case is perfect at all limes, the amount of pressure that can be developed and sustained depends solely on the strength of the machine and the power applied. Each of the two impellers is cast in one piece and well ribbed on the inside to prevent changes in form under varying condi- tions. It is part of our shop practice to press the shaft into the impeller with a hydrostatic press, finish the journals to standard size, mount the impeller on a planer and plane its entire surface accurately. By this means we secure perfect symmetry and ex- actness with respect to the journal on which it revolves, and, as a consequence, can produce a machine that will run more smoothly, and in either direction, at a higher speed and press- ure than it has been possible to attain heretofore. It will be observed that the C}'cloidal curves produce an im- peller with a broad waist. We have availed ourselves of this to use a high grade steel shaft of about twice the sectional area of those foinid in competing machines. The advantages of this need not be enumerated. BLOWERS. 419 In Fig. 89 we illustrate the style of blowers that are most largely sold, i. e., those pulley driven. It will be noticed that we use one pulley only. We can, however, when desired, put a pulley on each end, but because of the large shafts, wide-faced gears, and the fact that there is a bearing the entire distance from HORIZONTAL BLOWER. the gears to the impellers, it is seldom necessary. In any event, we do not recommend two belts very highly, as, owing to the difference in the amount of stretch in the leather, it is usually the case that one transmits most of the power. Indeed, it sometimes occurs that they work against each other. NUMBERS, CAPACITIES, ETC., OF THE CYCLOIDAL BLOWERS. Number of Blower •Capacity in cubic feet per rev- oluiion Ordinary speed Diameter of pipe opening .... 400 350 4 6 3 300 5^ 8i2i^24>^ 42 07 100 27s 250 200 175 150 125 100 10! 121 14 16, 20 24 30 By " ordinary speed " we mean what would be about an average of every-day duty. It must be understood, however, that the peculiar form of the impellers of our blowers, in con- nection with the other superior points in construction to which we have called attention, permits of higher speeds than com- peting machines. 420 THE CUPOLA FURNACE. The speed at which positive pressure blowers are run may be classed as "slow"; therefore power can be taken direct from the main line of shafting or from a countershaft driven at the same rate. Fig. 90 shows a blower with an engine to furnish the required power, both on the same bed-plate. By such a combination all shafting, pulleys, gears and belts are dispensed with, as the crank-shaft of the engine is coupled direct to a shaft of the Fig. 90. VERTICAL BLOWER AND ENGINE ON SAME BED-PLATE. blower, thereby efifecting a very simple but most efificient driv- ing- arrangement. We recommend the installation of such a plant when the blower is to be located at a considerable distance from the line shaft, as it will be found more economical to pipe steam to the engine than to transmit power by shafting or cable. But even where power is convenient there are many good reasons why it will be found much more desirable to operate the blower with its own engine. For instance, it can be run independent of the other machiner>', as necessity or conven- BLOWERS. 421 ience may often require, and also permits the speed of the blower to be varied as there is a demand for an increased or diminished amount of blast, while otherwise this could not be accomplished without a change of pulleys. In nearly every town there is now a station for electric-light- ing purposes, and managers of it are finding that they can extend the earning capacity of their plants and increase their profits by renting power at a time when otherwise their machin- ery would be practically idle. We have arranged to have our Fig. 91. BLOWER AND ELECTRIC MOTOR. machines operated by electric motors when desired. In Fig. 91 will be found an illustration of a motor geared direct to a blower, both on the same bed-plate. When preferred, how- ever, the motor can be located a short distance away, and the power transmitted to the blower pulley by means of a belt. Foundries and other industries needing power only to run their blowers will find it exceedingly advantageous and economical to adopt this plan. Not only will there be a saving in first cost, but the operating expense will be much less. Furthermore, the motors can have sufficient power to run the rattler and other light machines about the establishment. 422 THE CUPOLA FURNACE. ROOT S ROTARY PRESSURE Br OWERS. In the latest improvements in the construction of these blowers, the manufacturers assert that they represent the up- to date developments in this class of machinery, because with an experience of forty years in the construction of rotary pres- sure blowers, their improvements mean that they adapt and adopt such features as will meet the requirements of the trade, and at the same time eliminate what their long experience teaches them would be objectionable in the construction of this class of machinery. They claim that their machines represent the best class of workmanship, material and design, the highest efficiency, the Fi<:. 92. ROOT'S VERTICAL PRESSURE BI OWER. greatest durability, and 'a positive guarantee that a given quan- tity of air under a given pressure will be delivered with less power than any competing machine. In the most recent constructions the shape of the blower cases has to some extent been changed, and they are now con- structed vertical and horizonal as shown in Figs. 92 and 93. They are also made with blower and engine on same bed-plate or with blower and electric power motors on same bed-plate. The following claims are made for it by the manufacturers: BLOWERS. 423 1. It is simpler than any other blower. 2. It is the only positive rotary blower made with impellers constructed on correct principles. 3. It is the best, because it has stood the test of years and is the result of long experience. 4. In case of wear of the journals, the impellers will not come together and break, or consume unnecessary power, as is the case with competing machines. 5. The princii^les upon which our blowers are constructed admit of more perfect mechanical proportions than any other. ROOT'S HORIZONTAL PRESSURE BLOWER. 6. The only perfectly adjustable journal box for this type of machine is used. 7. The gears are wide- faced and run constantly in oil. 8. The gears and journals are thoroughly protected from dust and accident. 9. Our machine blows and exhausts equally well and at the same time, and the motion may be reversed at any time. 10. All the operating parts are accurately balanced. The principles upon which our blower is constructed are so radically different from any competing machine that we are enabled to adopt proportions that are mechanically perfect, and 424 THE CUPOLA FURNACE. hence we can speed our machines much faster than any other, with a far greater degree of safety. We are not compelled to cut down the weight of our blower cases, as other manufacturers do, in order to bring the weight of the complete machine within reasonable bounds. The distribution of metal in the shafting, impellers, gears and cases of all our blowers is perfectly pro- portioned, and it is the only rotary positive blower made so constructed. GARDEN CITY POSITIVE BLAST BLOWERS. In Fig. 94 is shown the Garden City Positive Blast Blower, manufactured by the Garden City Fan Co., Chicago, II!., many Fk;. 94. GARDKN CriY POSITI\'E BLAST BLOWER. of which are in use in foundries, and for which claims are made as follows : The operation of our blower is not on the fan principle, in which pressure is obtained by a high velocity or speed, but when the air enters the case at the inlet and is closed in by the vanes of the blower, it is absolutely confined and must be forced BLOWERS. 425 forward until finally released at the outlet, where it must have escape or the blower stop if outlet is closed. There is posi- tively no chance for loss by backward escapement of air, after it once enters the inlet. In many respects our blower has points of superiority over any positive blower made, and we call your attention to the following points : 1st. It has no £:^ears whatever. No internal parts that re- quire attention, adjustment or lubrication. 2d. It has only two journal bearings that are external to the blower casing. They are self-oiling. Easy of adjustment. 3d. Has no irregular internal surfaces that require contact to produce pressure, and add friction. 4th. Operating parts are always in perfect balance, thus blower may be safely run at a higher speed than any positive blower made, giving a proportionate increase in efficiency and a smaller blower may be used. 5th. A higher pressure can be obtained than is possible with any other. 6th. The blowers are practically noiseless as compared with all other makes. STURTEVANT HIGH-PRESSURE BLOWERS. Since the publication of the second edition of this work the B. F. Sturtevant Co. have perfected and placed upon the market a new high-pressure blower, Fig. 95, designed for handling air or gas at any pressure below ten pounds per square inch. They may be used to advantage in supplying air blast for foun- c'ry cupolas, forge fires, smelting furnaces, hardening, temper- ing, and annealing furnaces, whether supplied with coal, gas or oil; for pneumatic tube systems ; for moving granular material ; and in fact for furnishing air or gas for any purpose where the maximum pressure does not exceed the limit of ten pounds. The blower, which is of the so-called positive type, is manufac- tured in a variety of sizes and capacities ranging from five cubic feet to over 15000 cubic feet per minute. 426 THE CUPOLA FURNACE. The blower consists of four principal parts : the cast-iron shell or casing, two rotating members, or rotors, and a station- ary core. The rotors are held in position by bearings mounted on the end plates, and are made to revolve at the same speeds being connected by gears. As one of the rotors, called the impellers, revolves, it forms pockets or chambers in the annu- lar space between the core and the shell which imprison the air and carry it from the suction to the discharge, its return being prevented by the other rotor. Each pocket, as it nears the discharge, is decreased in volume, and consequently delivers its air at greater density. Fig. 95. i The other rotor, called the idler because it does no work,, simply acts as a valve to allow the impeller-blades to return to the suction side of the machine without loss of compressed air.. All the work of compressing and moving the air is done by the impeller which is mounted on the driving shaft, and no power is transmitted through the gears to the idler except that which is necessary to overcome the friction of the journals. Because all the work is done by one shaft, the load on the engine or motor is constant, the gears are relieved of all but a small fraction of their usual duty, and the wear is correspondingly reduced. BLOWERS. 427 , il n. p n! 0) -5 '^ Q -o ;^ ^ — ' .S3 5 5 Q "H 0- "" ro 000 00000 o i>- o o ' J rn •& iy~, 1^00 o vO O O N VD X X X X X u~i ir^oo 00 N X X X X X 00000 00000 vij i^ Ln o O « « M M X X X X X M N u-1 li-)X) X X X X X 'x -^ C O M 3 1-c f O ir-, I^ 00000 00 t^ O O O 0-0 u-i 1-1 &^^ CI e o5 K r- ." QlS 1-1 >-c M M M ro X X X X X X t1- -^ uo t-^00 O X X X X X 00 00 O O M X X X X X a I « B — ^ c C rt w- — >-^ -i5 ° H c ^ 00 O o «-< CL, O 3 II ^ ii a; fl 3 w< U c r/! ui a. cs ir" ■ ' \tM o o o o o "■^ O O O O O M O 00 00 vO li^ u-1 >J-i O O O o i^ r^ Tj- o CO ly-l ir^ u-1 O TO lo u^ Lri O "^ 10 Tl- ■* T <^ O O O O 10 VO O ONCO O ro ro C< P) ^ 00000 -O fO -^ O O LTi o "^ ^^ ^ -T i-T pT ro in O O O C N ^O fO ■* O ro m O *o ^'^ 00000 00000 00000 00000 r^ O "^ -" "^ rf 000 " LO f^ t^ O u^ *^ •J9A\oi3 JO jaquinjyf O ►« CI to ■^ IDVO t^oo o> o >-' p< <^ 428 THE CUPOLA FURNACE. Sturtevant electric motors and engines, especially adapted for use with these blowers, may be connected to the blowers in a number of different ways. Air or gas at atmospheric or suction pressure entering the blower at the intake is successively imprisoned in the three pockets formed by the three blades of the revolving impeller, and, since these volumes are reduced as the impeller- blades pass into the idler spaces, the air is discharged at any desired pressure up to ten pounds per square inch. The volume of free air displaced per revolution is constant, the pressure vary- ing with the speed and with the resistance to the passage of air. The principle upon which the blower operates is clearly shown by the diagram, fig. 93, which is a sectional view illus- trating the design and inside construction of the blower, fig. 94. The extreme high pressure for a rotary blower attained by this blower at once brought it into prominence and it has been in- stalled in many plants. PIQUA POSITIVE BLOWERS. Another positive pressure blower, that has attracted con- siderable attention of late, is The Piqua Blower. This blower is constructed upon the same general principles as the Root's and Connerrsville Blowers. In fact all the positive pressure rotary blowers are constructed upon the same general principles and it is only the material used in construction, and workman- ship that makes one more desirable than the other, for each delivers about the same volume of air per revolution of the same sized blower and requires about the same per cent of power to run them. FAN BLOWERS. The Sturtevant Bloivers. A third of a century has elapsed since the Sturtevant Steel Pressure Blower was first introduced as an indispensable factor in many manufacturing processes. Of the greatest importance has been its influence upon cupola practice. Before its advent, the rotary blower and the blowing engine were the only devices BLOWERS. 429 available for the production of blast sufficient for the melting of iron. It was at once asserted that a fan blower could not create sufificient pressure, was less efficient and less serviceable than the rotary blower. But Mr. Sturtevant, with characteristic energy and zeal, soon disproved these statements, made the fan an active competitor, and soon the worthy successor of the rotary blower ; and all this because the merits of the fan were emphatically proven, clearly presented and readily appreciated. STEEL PRESSURE BLOWERS. Although these blowers were originally designed for use in connection with cupola furnaces and forges, they are equally efficient when employed for producing mechanical draft for steam boilers, where high air pressure is required in connection with mechanical stokers, for producing the blast in sand blast Fig. 96. machines, for use in connection with pneumatic tube delivery systems, and in fact for any purpose where high pressure is to be maintained or where air or gas is to be forced long distances. The shell (Fig. 96) is of cast iron, bolted together and pro- vided with an outlet. The shaft is of high-grade steel, carefully finished, and the wheel and boxes are as described on a suc- ceeding page. 430 THE CUPOLA FURNACE. Number of Outside Diameter of Outlet in Inches. Diameter and Face uf TuUey, in Inches. Weight, m Pounds. Blower. Not Packed. Packed. OOOO CO o 2^ 4 1% X 1% 3 X2>^ 17 35 55 •35 65 90 I 2 3 4% 5% 6>i 3^ X 2l^ 3^X2% 4>^x3 75 95 155 100 140 220 4 5 6 7l^ I034 5 ^iVi 6% X 4ii 225 330 460 310 3^5 500 7 8 9 lO 12 133^ i6 i8X 7Kx5^ 938 X 63^ icig X 8 12^8 X 9% 695 870 1,615 2,100 740 920 1,680 2,175 SfEEL PRESSURE BLOWERS ON ADJUSTABLE BED WITH COMBINED UPRIGHT ENGINE. This type of machine (Fig. 97) represents the acme of con- venience and economy. It may be shipped ready for immediate operation, and may be used in any location to which a steam pipe can be conducted. The merits of the adjustible bed have already been pointed out. Its combination with an upright engine insures perfect alignment, rigidity, ease in adjustment, perfect control over the tension of belts, and, when desirable, an instantaneous change in the speed of the blower independ- ently of any portion of the plant. Both of the styles of the engines employed are identically the same in design, workmanship and material as the regular automatic engines. The double enclosed upright engine is peculiarly fitted for this service. All the running parts are thoroughly protected from the dust that forms an inherent part of the atmosphere in or about any foundry or forge shop. The oil-cups are all placed upon the exterior of the frame, so that continuous oiling is possible without the repeated opening and closing of the door. The short stroke, the perfect balance of BLOWERS. 431 the reciprocating parts and the large wearing •surfaces make Fig. 97. high rotative speed possible and render this engine unexcelled for the purpose for which it is designed. 4 to 8 oz. Pressure. 8 to 12 oz. Pressure. Number of Blower. Style of Engine. Diameter of Cylinder. Stroke. Weight in Pounds. Style of Engine. Diameter of Cylinder. Stroke. Weight in Pounds. 4 4 4 1,300 4 3 1,650 5 .£f 5 5 1.750 ! bo 5 4 2, ICO 6 0. — "5) 6 6 2,300 0. T3 6 5 3.500 7 m 7 7 3.650 _o c U 3 3 6 5 4,050 8 9 ID Double Enclosed Upright. 6 6 7 5 5 5 5.500 6,300 7.950 7 7 8 5 5 5.400 6,400 8,6co ELECTRIC STEEL PRESSURE BLOWERS. Electric blowers of this type are obviously applicable for all purposes for which the ordinary form of steel pressure blower may be employed. The fact that in the case of blowers with 432 THE CUPOLA FURNACE. direct-connected motors it is possible to place them wherever most convenient, and then make connection by wire, is most suggestive of their universal adaptability. All connecting belts and shafting, or the presence of a special engine and the neces- sary steam piping, are thus avoided. The blower is usually readily portable, and therefore easily adapted to changed con- ditions. The electric steel pressure blowers are principally used for the blowing of forge fires and cupola furnaces. Fig. 98. although equally serviceable for any work for which the regu- lar type is adapted. The general construction of these blowers is evident from the accompanying illustration. Fig. 98. In the smallest sizes the motor is of the bi-polar type, circu- lar in form, extremely compact and attached directly to the side of the blower, which is otherwise perfectly regular in its character. Where the atmosphere is free from dust, the open type may be employed. Otherwise, the enclosed construction is prefer- able. This is especially designed for foundry work, and may be introduced in either of two forms. That is, the motor may BLOWERS. 433 be adjustably attached to the fan; or the motor, with its en- closing ends, may be independently mounted, and the fan attached in such manner that it may be turned to discharge in any direction. The largest sizes of electric steel pressure blowers are equipped with multi polar motors of the independent circular type. This form of motor is placed upon a high bed, which in connection with the fan to which it is bolted serves as an ex- tremely solid foundation. In the belted arrangement the same type of motor is em- ployed. This form of construction is desirable where the speed of a direct connected motor would of necessity be ex- cessive, or where for certain reasons such an arrangement would be undesirable. Dififerent-sized motors may be fitted to the same blower, thereby making possible a great number of combinations, with speeds and cai)acities dependent upon the current and the size of the motor. These electric blowers are regularly made with bottom horizontal discharge, but may be made to discharge either upward, downward, or horizontally at the top, when so ordered. In asking for estimate state clearly what work it is de-ired the blower should do, and give the voltage of the current available. BUFFALO STEEL PRESSURE BLOWER. In Fig. 99 is shown the latest improved construction form of the Buffalo Steel Pressure Blower, for cupola furnaces and forge fires. A distinguishing feature of this blower, common to those of no other manufacture of the same type, is the solid case, the peripheral portion of the shell being cast in one solid piece, to which the center plates are accurately fitted, metal to metal. It will thus be seen that the objectionable and slovenly " putty joint " is entirely dispensed with. Ready access to the interior of the blower, without entirely taking it apart, is also thus afforded. With blowers of other manufacture, the "putty joint" feature of the shell or casing is an indispensable adjunct, 28 434 THE CUPOLA FURNACE. although it is a construction-point which is, at the best, some- thing to be avoided in an efficient machine. The Bufifalo Steel Pressure Blower is designed and con- structed especially for high pressure dut)', such as supplying blast for cupolas, furnaces, forge fires, sand-blast machines, for any work requiring forcing of air long distances, as in connec- tion with a pneumatic tube delivery system. It is adapted for all uses where a high pressure or strong blast of air is re- FiG. 99. .^-if / M: Slt-EL I'KESSUKE Kl.OWEK. quired. The journals are long and heavy, in the standard ratio of length to diameter of six to one, and embody a greater amount of wearing surface than those upon the blower of any other construction. Attention is directed to the patented jour- nals and oiling devices employed on this blower, which are unique features. The bearings are readily adjustable, and any wear can be taken up, which is an important point attending the durability and quiet running of a perfect machine. The Bufifalo Steel Pressure Blower possesses the fewest num- ber of parts of any like machine; in fact, the blower is prac- BLOWERS. 435 tically one piece, so that under any service the bearings invariably are in perfect alignment, vertically and laterally, with the rest of the machine. In the items of durability, smooth running and economy of power, it is thus rendered far superior to any blower with the so-called universal journal bearing which is commonly employed. In every point of construction the greatest pains have been taken to simplify all parts, and at the same time to give them the greatest strength. To adjust, repair and keep in order a BufTalo Blower is a very small matter and readily understood by a machinist of average ability. For obtaining the best results from a blower of given size, when used for melting iron in foundry cupolas, much depends upon the proper lay-out of the blast piping between the blower and the cupola, and also upon the proper proportionment, ar- rangement and design of the cupola tuyeres. Several forms of cupolas are now upon the market, economical in the use of fuel and fast melting, which are the points most sought for in cupola construction. It is a common but erroneous idea that a blower large for the work will give better results, in a given diameter of cupola, than a smaller one. In the tables which accompany the blower we give the proper sizes of blower for different diameters of cupolas; but it must be borne in mind that if the tuyerage is not of sufificient area, or if the blower has to be located at some distance from the work to be accomplished, these points enter for consideration. Frequently foundrymen, when experiencing difficulty in obtaining satisfactory melts, throw the whole cause of the trouble upon the blower, when the fault does not lie at this point. It is safe to say that failures are due more largely to the mism.anagement of a cupola and improper application of the blower than to any other cause. The BufTalo Steel Pressure Blower is especially adapted for foundry cupolas, and is guaranteed to produce stronger blast with less expense for power than any other. 436 THE CUPOLA FURNACE. BLOWER ON ADJUSTABLE BED, AND ON BED COMBINED WITH COUNTERSHAFT. Unless considerable care is taken in putting up countershafts^ and some special attention is given to keep them in. perfect alignment, trouble is often experienced, especially in keeping the belts on the larger sizes of blowers, on account of the great speed at which they have to run to produce high pressures. To overcome such features, this house designed the adjustable bed, and the adjustable bed combined with countershaft ar- rangements, which is illustrated in Fig. lOO. The blower on adjustable bed, alone, without the countershaft, is very con- ¥\G. lOO. HI.OWEK AXD COUNTERSHAFT. venien.t for taking up the slack in belts while the fan is in motion and driven by belt from main line. In Fig. lOO is shown the latest construction form of Buffalo Steel Pressure Blower on adjustable bed with combined coun- tershaft. Its use will be found to result in a decided saving in the wear and tear upon belts, which, in a short time, more than justifies the extra initial expense of the arrangement. The cost will be found liitle in excess of ordinary method, and a few turns of the nut on the end of the adjusting screw, which is BLOWERS. 437 clearly shown directly under the outlet of the blower, after first loosening the holding-down bolts, which should afterward be re-tightened, accomplish, in a very few moments, what, previous to the introduction of this apparatus, has caused considerable delay and annoyance. It will readily be seen that the usual frequent relacing of belts, to make them sufficiently tight to avoid slipping, is hereby entirely obviated. Positive alignment of the countershaft with the shaft of the blower by this arrangement causes the belt to track evenly, run smoothly and avoid the usual wear by their striking against the hanger or side of the blower. As will be readily appreciated, the tightening screw gives the same uniform tension to both belts, and this may be regulated at will of operator. A tele- scopic mouth-piece, as is shown by the cut, is placed upon each blower purchased in this form, which enables the machine to be moved upon its bed without any disarrangement of the blast piping. Especial attention is called to the fact that the arrangement of blower on adjustable bed combined with countershaft, as illustrated in Fig. lOO, occupies the smallest amount of space consumed by any apparatus of this kind manufactured in the world. Ordinary tight and loose pulleys are placed upon the countershaft from which the power is transmitted to the coun- tershaft of this apparatus. When this feature is not desirable, which is often the case where power is transmitted from the main line without the intervention of a countershaft, the adjust- able bed countershaft may be furnished with the blower, so that it will extend at the right or left, as desired, and the tight and loose pulleys are then placed thereon ; we then' have a right or left hand apparatus. The space between the two pulleys which drive the blower is not wide enough to permit of the introduction of tight and loose pulleys. BUFFALO BLOWER FOR CUPOLA FURNACES IM IRON FOUNDRIES. In the following table are given two different speeds and pressures for each sized blower, and the quantity of iron that 438 THE CUPOLA FURNACE. may be melted per hour with each. In all cases, we recom- mend using the lowest pressure of blast that will do a given work. Run up to the speed given for that pressure, and regu- late the quantity of air by the blast gate. The proportion of tuyerage should be at least one-ninth of the area of cupola in square inches, with not less than four tuyeres at equal distances around cupola, so as to equalize the blast throughout. With tuyeres one-twentieth of area of cupola, it will require double the power to melt the same quantity of iron, and the blast will not be so evenly distributed. Variations in temperature afTect the working of cupolas very materially. Hot weather requires an increase in volume of air to melt same quantity of iron as in cold weather. Table of Speeds and Capacities as Applied to Cupolas. in T3 ■•-' * u *o t u u o a il 3 S a* rt HH •SO S ■" • '-''9 m U U IH c . so d s . a, PI u 1- T^ C/2 Q fu en 2 U p-( ca; ^-. u 4 4 20 8 4732 1545 666 9 5030 1647 717 5 6 25 8 4209 2321 773 10 4726 2600 867 6 8 30 8 3660 3093 951 ID 4108 3671 1067 7 14 35 8 3244 4218 i486 10 3642 4777 i6fe8 8 i8 40 8 2948 5425 2199 10 33>o 6082 2469 9 26 45 ID 27«5 7818 3203 12 3260 8598 3523 ID 36 55 10 2195 11295 4938 12 2413 12378 5431 II 45 6S 12 1952 16955 7707 14 2116 i«357 «35« III/^ 55 72 12 1647 22607 10276 14 1797 25176 1 1 144 12 75 84 12 1647 25836 1 1 744 14 1797 28019 12736 "a. b. c." steel pressure blowers. The A. B. C. Steel Pressure Blowers of the American Blower Co. are especially designed and constructed for delivering air at high pressure. They are, therefore, adapted for supplying blast for cupolas, forges, etc., and the following claims are made for them : BLOWKRS. 439 Centrifugal Pressure Blowers have many advantages not possessed by blowing engines, rotary or so-called positive blowers, or other devices built for the same class of work. These advantages may be briefly summarized as follows: I. The cost is from one-fourth to one-third the cost of a rotary blower. 2. It weighs about one-eighth. 3. Occupies less than one-third the floor space. 4. Requires from one-third to one-half the power to produce the same results. 5. Can produce a steady pressure of 20 ounces per square inch, which is the maximum required for any furnace or cupola. 6. The volume discharged is proportional to the resistance, automat- ically increasing if another cupola or furnace is added. The power required to drive the blower is almost proportional to the volume, being little more than the friction of the bearings when the blast is closed off. With a rotary blower, adjust- ments have to be made for every change of conditions and the. power remains at the maximum whether the blast is off or on. 7. The mechanical efificiency is from 50 to 85 per cent, greater (varying with the age of the rotary blower), due to wear of the impellers, gears, and other mechanical leakages and lost motion. 8. A Centrifugal Blower automatically adjusts itself to the work, always producing results with the highest possible efficiency, whereas the rotary blower is dependent entirely upon the skill and intelligence of the operator for the results attained. 9. Centrifugal Blowers have run for years without any expense for repairs. Rotary blowers require constant attention and fre- quent overhauling to keep the impellers in such condition as to reduce excessive leakage. 10. There is no pulsation to the blast, which is even, smooth, and steady under all conditions — a most desirable condition. 11. The term "Positive Blower," so commonly applied to rotary blowers, or those having impel- lers revolving in close proximity to one another, is very mis- leading. They are not "positive" in any sense of the word. The impellers cannot rub together; if they did they would soon wear so there would be no contact. As the bearings and gears wear the leakage becomes greater. The whole machine 440 THE CUPOLA FURNACE. has to be taken apart to make repairs. It is made of very heavy and cumbersome parts, hard and awkward to handle, making emergency repairs difficult, if not impossible. The Centrifugal Blower is light and simple in construction, easily accessible, requires no repairs (barring accidents) except re- babbiting the bearings ; is equally as positive in delivery, and far more economical and simple to operate. That this is the general opinion is proven conclusively by the vastly greater number of Centrifugal Blowers in use than any other type. Fig. ioi. In Fig. IOI may be seen one of these blowers in a foundry, illustrating position of blower-pipe connection, method of ap- plying power, etc. Blowers of this type are designed to be driven b)' direct con- nected electric motors. Pressure blowers of standard propor- tions run at speeds altogether too fast to be electrically driven, but by increasing the diameter of the impeller and altering the proportions of the other parts, the speed can be made to con- form with that of any motor; and at the same time the blower will produce any pressure and deliver any volume of air within the possibilities of accomplishment with centrifugal pressure blowers. These blowers are built entirely of steel, amply strong for BLOWERS. 441 the severest conditions. They are far more desirable than the smaller high-speed blowers which are driven by belt. The motor is attached by a flexible coupling, which avoids any trouble from imperfect alignment through the use of four bearings in a row, two of which are on the motor and two on the blower. CHAPTER XXVI. FOUNDRY TRAMRAIL. Foundry transportation is receiving more careful attention to-day than ever before. For the foundry the day of the wheel- barrow and industrial track is over and, on account of their many disadvantages and costly operation, they are becoming obsolete. The mostefificient method thus far used is an overhead tram- FlG. I02. TRAMRAIL OVER THE STORAGE YARD — WITH LIFTING MAGNET CARRYING COKE. rail or trolley track as it is sometimes called. By means of this tramrail one man will handle easily loads weighing up to one ton. Briefly described, the tramrail consists of a steel I beam of (442) FOUNDRY TRAMR\IL. 443 standard section, running on tlie lower flange of which is a four wheel trolley. Suitable hangers can be made to attach this rail to the overhead roof trusses or other supports. An I beam makes an inexpensive form of rail in that the hangers neces- sary to support it can be placed as far apart as twenty feet, and a ton load be carried. As used in the average foundry, the main line extends out along the wall in the storage yard with branch <^witches and tracks running to the piles of coke, scrap and pig. A section of the rail is placed on the elevator and on the platform, and a Fig. 103. CARRYING COKE FROM THE STORAGE YARD TO THE CHARGING FLOOR. loop around in front of the charging door of the cupola. One man in the yard will load self-dumping buckets with coke, or racks with pig or scrap, and shove them over the tramrail in the yard to the elevator. Here the yard rail and the section of the tramrail on the elevator come to a common level and the load is shoved, still on the trolley, on to the elevator, is raised and pushed ofT on the trolley to the loop in front of the charging door. Scrap and coke may be dumped directly into the cupola and in the case of pig the rack or cradle is run near the door and the pig thrown into the cupola where wanted. The ingredients for the entire charge may be run up to the 444 THK CUPULA FURNACE. platform and stored, and when the heat is on, the yard man may be used on the platform. In some cases an hour's melt may be stored and one man left in the yard to bring up the charge for the next hour. As the most efificient method is to weigh each charge, a scale may be inserted in the rail and the load weighed as it moves along. The scale is usually placed in the rail in the Fig. 104. CHARGING SCRAP BY MEANS OF TKAMRAIL. yard just before the load passes to the elevator. By this method no rehandling of the pig, coke or scrap for weighing or charging is necessary. In foundries of larger capacities, the tranirail may extend out over the yard on the same level as the rail on the platform, an electric trolley and hoist be provided, and for lifting pig and scrap, and electric magnet. By means of this system one man FOUNDRY TRAM RAIT.. 445 in the trolley cage and one or two men in the yard will not only convey to the charging floor the ingredients for the heats up to lOO tons, but will unload the incoming cars of pig and scrap. We know of one installation of this kind wherein three men and an electric tramrail are all that are necessary to convey pig, scrap and coke for lOO tons daily melt as against twenty-three men in the old way of wheelbarrows, industrial tracks and cars^ Fig. loe. CHARGING COKE IN A DUMP BUCKET SUSPENDKD FROM TRAMRAIL. A tramrail for carrying molten metal from the cupola is a labor-saving appliance well worih consideration. Starting in front of the cupola spout a loop should extend to the main line of the tramrail system and by means of curves and switches be so designed as to enable a load to make a con- tinuous loop so that full ladles pass one way and come back empty to the cupola a different way. This is necessary as it is not good practice to have a full ladle wait for an empty one to pass out of its way. If a continuous loop of rail is not installed 446 THE CUPOLA FURNACE. there should be frequent cut-outs or switches enabling the full to pass the empt)' ladle. For continuous pouring, the best way is to provide a tilting spout on the end of the regular .cupola spout. By means of this, an empty ladle may be placed directly against the ladle receiving its metal, so that when filled, the tilting spout is tip- ped so that the metal runs into the waiting ladle. This does away with tapping the spout, insures a continuous stream and consequently better mixed metal. Ladles containing up to 1500 lbs. of metal are shoved by one man to any of the floors and poured direct mto the flasks Fig. 106. LADLES BEING ULLED AT THE C'JPOLA SPOUT. if the castings are heavy, or into the ladles of the moulders at the floors if the castings are light in weight. It is admitted, that the larger the volume of metal carried, the longer it will stay hot, so that if large bull ladles are carried to the floors in place of one or even two man shank ladles the metal will be delivered to the flasks at a higher temperature, cleaner and more uniformly mixed than by any other method thus far designed. Theoretically, if it were possible to bring the flasks up under the cupola spout better castings would result. Again, if it were possible to place a number of small cupolas over the FOUNDRY TRAMRAIL. 447 foundry, one at each floor, better castings would result. Both of these methods of course are impossible, but what can be done is to carry the metal in large bulls from the cupola to the floor. It should be borne in mind, that an excess ladle capacity of 33/^ per cent, is absolutely essential in order that the ladle may be quickly moved about without any possible danger of slopping the metal. In addition to carrying the charge and supplying metal to the floors, tramrails can be used to do nearly all of the carrying around the foundry and a well designed system, well installed and put to all the uses for which it is so well adapted, will pay for its original cost several times each year it is used. I m NDEX. A. 441 Abendroth Bros., cupola report of, 292 tuyeres in the cupola of, 58 Adjustable tuyeres, 60, 61 Air, amount of, required for combus- tion of fuel. -IIU and coke, ratio of, 220, 221 capacity for moisture, 217, 218 chamber, 5, 29-31 chambers, connection of, with blast pipes, 399-401 dry, for the cupola, 223, 224 effect of heat on, 218, 219 gauges, 389 temperature of, 220 Alloys, melting of. 279 American Bio ^er Co., steel pressure blowers of, 438-441 Angle irons, arrangement of, 39-41 Anthracite coal as a cupola fuel, 230- 238 pounds of iron melted with one pound of, 113 quantity of, for bed, 98 Apron, 90 Art iu melting, 280-290 B. C. steel pressure blowers, 438- • Bedstead work, small cupola for, 175, 176 Belgium, small cupolas of, 178, 179 Belt air chamber, connection of, with tuyere, 401 Bessemer steel, melting pig iron in the manufacture of, 'St"! Bituminous coal as a cupola fuel, 252- 254 Blakeney cupola, 376-378 tu\ere, 50, 51 Blast, '1U8 adding steam or water to, 222, 223 admission of, to air chamber, 31 best way to put on, 110 closing the tap-hole before put- ting on, 11(1, 111 delay in putting on, 388, 389 driving of, to the center, 15 dry, Gayley, 223 failure of healing, 215 fallacy of the theory of heating, 209 freezing the, 215-224 furnace, fuel required for, 1 gates, 404-406 gauges, 406-408 hot, theory of obtaining, 210 in melting, 4(i8-413 machines for supplying, 408 moist or dry, 222, 223 moisture in, 210, 217 old theory of, 15 -pipes, 394-103 and blast; 394-413 connection of, with air-cham- bers, 399-401 with cupolas, 397, 398 with tuyeres, 399 diameter of, 397-403 and area of, 398 explosion in, 4(16 long, cause of poor melting, 4(i2 materials for, 395 BAILLOT cupola, records of ex- periments made on a, 214 cupolas. 210-213 Baldwin Locomotive Works, swing- ing crane with magnet attached at, 313 Bancroft, M. H., on weather and the output of the cupola, 217-222 Banking a cupola, 286-288 Basin spout, 316 Bed, 98-1(10 arrangement of, 95, 96 burning up the, 96, 388 leveling the top of, 103 raising or lowering a, 99, 100 uneven burning of 201 weight of fuel required for, 100 29 ( 449 ) 450 INDEX. Blast-pipes, table showing necessary increase in diameter for difFert-nt lengths of, 396 underground, 394 positive and non-positive, 408, 4(i9 supply of, 12 taking off the, during a heat, 285. 28ti time for charging the iron before putting on, 1U9-111 Blossburg coke, 240 Blower and counter-shaft, 436 connections of tuyeres with, 5 load on, 219, 220 placing a, 4(l3, 404 Blowers, 414-441 types of, 414 Bod, making a good, 118 material 117-119 size and shape of, 119 steel bar for cutting away the, 116 sticks, 116, 117 support for, 121 wet, explosion of iron caused by, 302. 303 Boiler-plate casings, 13, 14 Bulling, cleaning iron by, 270, 271 or foaming slag, 331 Boshed cupola, lining of, 132 Bottom doors, 4, 25, 26 devices for raising, 26, 27 supports of, 4 hard ramtntd, 388 height of, 25 of cupola, height of, above moulding floors, 3 plate, 4, 41 removing props from the, 122 sand, 81, 282 wet, 3S8 tuyere, 61-64 Brackets, arrangement of, 39-41 Brass, melting of, 279 Breast building a, 90 plate, 90 Brick for lining. 1.34, 135 lining, common red, 335, 336 stack cupolas, 13 Bricks for cupolas, 37 Bridge, breaking away a, 123 Browne & Sharp Manufacturing Co., stockyards of, 313, 314 Buckeye heater or oil torch, 97, 98 Buffalo blower for cupola furnaces in iron foundries, 4;-47, 438 Forge Co., banking the cupola of, 286-288 Buffalo School Furniture Co., explo- sion at, 306, 307 tuyeres in the cupola of, 69 steel pressure blower, 433-437 Burns, treatment of. 332 By product coke, 251, 252 By ram & Co., cupola report of, 293 pALUMET cupola, 152-155 v^ Calvin, Dan., description of a small portable cupola by, 168- 170 Canada Car Co., records of experi- ments made on a cupola of the Baillot system, 214 Carbon, effect of, on iron, 268 Carnegie Steel Works, device for charging cu- polas at, 325, 326 large cupolas at, 156, 157 Cars for removing dump, 124 Casing, 27-29 greatest wear on, 27 lining for, 6, 7, 37 rusting of, 40 strain upon, 27 Casings of cupolas, 4, 5 of stacks, 5 Cast iron blast pipes, 395 quantity of, that can be melted in a cupola, 272, 273 size and weight of, that can be charged, 273 Castings, report on, 296 Center 1)last tuyere, 61-64, 159, 160, 412, 413 Centrifugal blower, 440 Charcoal fuel, 228-2.30 Charge, weighing the, 444 Charges, heavy, division of, 105 placing the, 103-1U7 small, for a cupola, 327, 328 Charging, 100-103 and melting with anthracite coal, 232, 233 aperture, location of, 28, 29 coke, rule for, 245, 246 cupola slate for, and cupola re- port, 297 cupolas, devices for, 325-327 door, 6, 29 carrying coke from storage yard to, 443 INDEX. 451 Charging door, iudestructible wire screen, 147, 148 flux, 1(17 Cbenney tuyere, 56 Chill-mould, damp or rusted, explo- sion of molten iron when poured into, 304 Chipping out, 125, 126 protecting the melter when, 329, 330 Cinder, brittle, 259 tendency of, 259, 260 Clay sands for bottom, 81 Clays for daubing, 127 for spouc linings, 87 Cleaning iron by boiling, 270, 271 Climate and hot iron, 223 Coal and coke, mixture of, 236, 237 wood, bad melting caused by, 198, 199 anthracite, as a cupola fuel, 230- 238 charging and melting with, 232, 233 first use of, 231 pounds of iron melted with one pound of, 1 13 report from foundries show- ing per cent, of, consumed in melting, 234 size of, for melting, 234, 235 bitummous, as a cupola fuel, 252- 254 diflference in, 231 for lighting up, 95 Coke and coal, mixture of, 236, 237 by-product, 251, 252 carrying of, from storage yard to charging door, 443 charging of, in a dump bucket suspended from tramrail, 445 Connt-llsville, pounds of iron melted with one pound of, 113 conveyance of, to scaffold, 23 custom in the early days of melt- ing with, 242-244 difFt-rence in, 244 economy in melting with, 241 first manufacture of, 238 shipment of, 238 for cupola, :i38-251 lighting up, 95 good foundry, requirements in the manufacture of, 211 in summer and winter, 221, 222 ovens, first coke made in, 238 per cent, of, to iron, 250 Coke, poor, remedy in melting with, 247 quantity of, for bed, 98 reason for the variation in the quality of, 245 reports of melting with, 250 rule for charging, 245, 246 seventy-two liour, 244, 245 Sol way, 251, 252 Colliau cupola, 18-20, 137-141 hot-blast cupola, 205, 206 tuvere, 56 Combination bod-stick, 117 Connellsville coke, first record of use of, 238, 239 pounds of iron melt- ed with one pound of, 113 reports of melting with, 250 Connersville cycloidal blower, 415- 421 Construction of a cupola, 22-44 Cost of melting, 298-301 Crandall improved cupola with John- son patent center-blast tuyere, 374- 376 Cross spout, 316-318 Cupola accounts, 291-301 art of melting in a, 280-290 banking a, 286-288 Blakeney, 378 blast, moist or dry, 222, 223 blower placed near, 402 boshed, lining of, 132 bottom, 2 ht-ight of, 25 breast and runner, Moor's patent, 33^> brick, 37 bridgfd, section through, 130-132 bridging of, 15 casing, 27-29 charging a, 100-103 cheap, small, movable, 170, 171 coke, 238--i51 commencement of melting in a, 108, 109 construction of a, 22-44 Crandall improved, with John- son patent center-blast tuyere, 374-376 does it pay to slag a, 264, 265 drv air for, 223, 224 E.'j. R . 150-152 expanding, 342-344 fluxing a 107 * of iron in a, 258-271 452 INDEX. Cupola for melting tiu-plate scrap, 278, 279 foundation, 28, 24 fuels, 225-257 furnace, 1-7 advantages of, 1 description of, 2-7 first, used in this country, 8, 9 Gmelin's, 361-3G3 Greiner's patent economical, 367- 369 height of a, 28 Holland, 206-210 hoods, 385, 386 Ireland's, 344-346 center blast, 346-348 Jumbo, 371-374 Keep sectional, 171-173 McShane large, 157-159 Mackenzie, 357-361 management, 77-136 requirements for, 283, 284 melting capacity of a, 29 with charcoal in a, 229, 230 z .ne of, 98 number of men required to man a, 323-336 Newten, 141-144 old style stave, 338-341 on wheels, 176, 177 Paxson Colliau, 144-148 truck and track, 176, 177 proper location of, 22 Pevie, 363-365 piiks, 126 placing tuyeres in a, 411, 412 plain, round, 21 practice, oil in, 209, 210 reason why a, works better on a rainy day, 222 reservoir, 342 , scrap, charging of, 103, 104 scraps, 387-395 sectional view of, 38 slate for charging and cupola re- port, 297 small charges for a, 327, 328 for bedstead work, 175, 176 portable, 168-170 value of, as a money maker or saver, 164, 165 space theory of, 246 stationary bottom, 174, 175 Stewart's, 365-367 stock, getting up, 308-314 g supports, 24 swivel, 166-168 Cupola tank or reservoir, 354-357 tuveres, 45-76 utilization of heat from, 202-205 Voisin's, 348-350 warming up a, 196-198 weather and the output of the, 217-222 West's large, 159-161 what a, will melt, 272-279 Whiting, 148-150 wonderful, 254-257 Woodward's steam jet, 350-354 Cupolas, Baillot's, 210-213 Colliau, 137-141 connection of blast-pipes with, 397. 398 devices for charging, 325-327 for heavy work, tuyeres in, 68 forms and sizes of, 2 foundations of, 2 heights of, 13 high, importance of, 137 Homestead larjje, 156, 157 hot blast, 202-214 improvements in, 8-21 large, 156-163 advantages and disadvan- tages of, 161-163 modern, 137-155 of different diameters, height and size of door for, 29 scientificaliv designed, 337-378 small, 164-186 bod for, 118, 119 of Europe, 178, 179 spark catching devices for, 379- 393 steam jet, 369-371 trouble in slagging, 263, 264 DAUBING, 126-128 excessive, 130 material, 127, 282 from pieces of fire-brick, 135, 136 new method of mixing, 332- 334 object of application of, to lining, 128, 129 thickness of, 130 Doherty cupola, 17, 18 tuyere, 48, 49 Doors, devices for raising, 78 dropping the, 80, 81 props for, 78. 79 pulling up the, 78-80 table giving height and size of, 29 INDEX. 453 Double spout, 315, 310 tuyere, 57, 58 Draw front cupola, 8-10 Drop bottom cupola, 11, 12 Dropping the doors, 80, 81 Dry air for the cupola, 223, 224 Drying the lining, 77, 78 Dump, breaking up the, 123 picking over the, 124, 125 removing the, 25, 124, 125 Dumping, 122, 123 t^ J. E. cupola, 150-152 ^, Electric Controller and Supply Co.. lifting magnet of, 311-313 steel pressure blowers, 431- 432 Elevated stockyards, 313, 314 Elevator, 23 Elevators, 309-311 England, management of small cupo- las in, 171 use of tanks in, for mixing irons, 356 Europe, small cupolas of, 178-180 Examples of bad melting, 181-201 Expanded tuyere, 47, 48 Expanding cupola, 342-344 Explosion of molten iron, 302-307 Explosions in blast-pipes, 406 FAN blowers, 428-441 load on, 219. 220 Fire brick, daubing material from pieces of, 135, 136 clay for daubing, 127 soaking of, 129, 130 -proof scaffolds, 23, 41-44 sand, 81 Eloor, wet, muddy, explosion of iron caused by, 3(i3 Fluor spar, use of, as flux, 269, 270 Flux, charging of, 107 definition of, 258 effect of. upon iron, 261 use of fluor-spar as, 269, 270 marble spalls as, 265, 266 shells as, 265 Fluxes, action of, on lining, 261-264 influence of, upon front material, 91 materials used as, 258 Fluxing iron in a cupola, 258-271 limestone in large quantities for, 259-261 Foundations of cupolas, 2, 23, 24 Foundries report from, showing per cent, of coal consumed in melt- ing, 234 troubles in, 280 Foundry, retaining heat in a, 328, 329 tramrail. 442-447 transportation in, 442 work, general, best practical re- sults for. for melting, 391 Freezing the blast, 215-224 Front, 90-92 drying the, 91 material for, 90 poor, troubles due to, 91 too wet, 91 putting in the, 90, 282 Fuel, 113-115 amount of air for combustion of, 410 charging of, 100, 101 consumption of, in a double tuy- ere cupola, 58 in various fur- naces, 1 effect of too heavy charges, 102 for cupola, 1 gas and liquid, 225-228 misstatements regarding. 114- 115 utilization of greatest amount of heat from, 282 weight of charjics of, 103 required for a bed, 100 Fuels, cupola, 225-257 mixed, heats melted with, 236, 237 Furnaces, various, consumption of fuel in, 1 GALVANIZED sheet iron scrap, melting of, 277 Garden City positive blast blowers, 424, 425 Oas and liquid fuel, 225-228 -house coke, 241 Gates, charging of, 103, 104 Gayley dry blast, 223 Gebhard, Judge, early use of coke by, 238 Getting up cupola stock, 308-314 Gmelin, Dr. Otto, cupola of, 361-363 Gould & Eberhardt, cupola scaffold in the foundrj' of, 44 Great Britain, small cupolas of, 178 Green patented positive pressure blower, 415 Greiner patent economical cupola, 367-369 tuyere, 59, 60 454 INDEX. HAND ladle-work, mauagement of , 111 Heat, effect of, on air, 218, 219 production of, by consuming escaping gases, 59 retaining the, in a foundry, 328, 329 taking off the blast during a, 285, 286 utilization of, from cupola, 202- 205 waste, 221 utilization of, 1, 28 " Heater or oil torch, 97, 98 Heats melted with mixed fuels, 236, 237 Height of cupola, 28 bottom, 25 tuyere, 65-69 Hibler, B. H., tuyere patented by, 63 Hocking Valley coke, 240 Holland cupola, 2(i6-2l0 Homestead large cupolas, 156, 157 Hoods, cupola, 385. 386 Horizontal and vertical slot tuyere, 51 Horse manure for bods, 118 Hot-blast, 18, 19 cupolas, 202-214 theory of obtaining, 210 IMPROVEMENTS in cupolas, 8-21 1 Ireland's center blast cupola, 346- 348 cupola, 344-346 double row of tuyeres, 57 Iron, accurate determination of the resultant qualities of an, 165 action of. at the spout, 85 tin on, 276, 277 additional, charging of, 106 and coke, rule of charging, 247, 248 appearance of, at the tap hole, 109 boiling of, 84 charging of, 100, 101 chilling of, in the tap hole, 94 cleaning of, by boiling, 270, '.'71 cold, wet or rusted, explosion of molten iron caused by, 303, 304 cost of melting, 390 crates for removing dump, 124 effect of carbon on, 268 flux upon, 261 silicon on, 267, 268 experiments in melting, with gas and liquid fuels, 226-228 flow of, after blast is put on, 119 Iron, flow of. from tap hole, 1 12 fluxing of in a cupola, 258-271 foundries Buffalo blower for cu- pola furnaces in, 437, 438 fuel required for melting, 1 hot, and climate, 223 production of, 282 hotter, in winter, 215 in slag, 261 malleable, experiments in mak- ing, 266 melting large pieces of, 273, 274 of, in a cupola, different terms used to indicate, 387 molten, explosion of, 302-307 handling of, 389. 39(t holding of. in cupola, 111 per cent, of coke, to, 250 lost in melting, 266, 267 poling of, 270, 271 preventing the, from running into tuyeres, 125 size of coal of, for melting, 235 space in which melted, 98 sparks thrown off by, 3(l3 time for charging the, before putting on blast, l(i9-lll tuyeres to improve the quality of, 71 uneven melting of, 102 use of charcoal (or smelting, 228 weight of first charge of, 102, 103 Irons, first step in mixing, 104 TAGCER, Treadwell & Perry, hot J blast cupolas constructed by, 202- 205 Johnson, John D., & Co., trouble with the cupola of, 262 Jumbo cupola, 371-374 KEEP, J. W., investigation by, as to the number of cupola men required, 323-325 sectional cupola, 171-173 Knoeppel, Mr., on banking a cupola, 286-288 tuyere, 75, 76 LADLE, damp, explosion of iron caused by, 307 tapping, 321, 322 Ladles, filling of, at the spout, 446 transporiation of, 446 Large cupolas. 15H-163 advantages and disadvan- tages of, 161-163 1 INDEX. 455 Lawrence cupola, 16, 17 reducing tuvere, 53, 54 Lead, melting of, in a cupola, 272 Lebanon Stove Works, daily report of foundry department of, 294 Lehigh coal, 231 Lifting magnets, 311-313 Lighting up, 95-97 new method of, 97, 98 Limestone, amount required to pro- duce fluid slag, 260 as a cupola flux, 259 impurities in, 2(il, 262 in large quantities for fluxmg, 259-261 use of, in the production of pig iron, 258, 259 Lining, 37-39 absorption of moisture into, 41 action of fluxes on, 261-264 brick for, 134, 135 common red bnck, 335, 336 drying the, 77, 78 efi'ect of fluor spar on, 269 greatest wear of, 133 materials for, 6 mica schist, 334, 335 object of applying daubing to, 128, 129 of casing, 6, 7 out of shape, examples of, 181- 189 renewing a, 334 shaping the. 128-133 thickness of, 6, 7 Linings, new, 129 Liquid and gas fuel, 225-228 Loam s mds for bottom, 81 Lobdell Car Wheel Co., cross spout used by, 316- 318 experiments to produce a moist blast at, 216, 217 McSHANE large cupola, 157-159 Mackenzie cupola, 14, 15, 357- 361 tuyere, 49, 50 Machine and jobbing foundry cupo- las, tuyeres in, 68 Magee Furnace Co., tuyere used by, 54 Magnets, lifting, 311-313 Malleable iron, experiments in mak- ing, 266 Marble spalls, use of. as flux, 265, 266 Melter, give the, a chance, 288-290 protecting the, when chip^jiug out. 329, 330 Melting, 108-112 art in, 280 290 bad, caused by wood and coal, 198, 199 examples of, 181-201 best practical results for, for gen- eral foundry work, 391 blast in, 4(i8-4l3 brass in a cupola, 279 cost of, 298-:;01 fast, cupola for, 281 . 282 in old cupolas, theory of, 410 iron, cost of, 390 large pieces of iron, 273, 274 of iron in a cupola, different terms used to indicate, 387 per cent of iron lost in, 266, 267 point, 98 to find the, 99 poor, cause of, 106, 107 in a Ciucinnaii cupola, 199- 201 long blast-pipes cause of, 402 report from foundries showing per cent, of coal consumed in, 234 reports of, with Connellsville coke, 25() space theory of, 246 tin-plate scr^ip, co^t of, 390 in a cupola, 275-279 trouble in, lOO with charcoal, 229, 230 poor coke, 247 zone, 98 burning away of lining at, 134 Men, number of, required to man a cupola, 323-336 Mercury gauge, -106 Mica schist lining, 334, 335 Modern cupolas, 137-155 Moist or dry cupola blast, 222, 223 Moisture, air capacity for, 217, 218 in blast. 216, 217 temperature of, 221 Moldenke, Doctor, on small charges for a cupola, 327 Molten metal, explosion of, 83, 84 Moor's patent cupola breast and.run- ner, 336 • i Mud, explosion of molten iron'when poured into, 305 456 INDEX. ^I EW tuyeres, 72-76 t Newteu cupola, 141-144 North Bros., explosion at the foundry of, 8(»o, 3(>6 Number of tuyeres, 69, 70 OIL in cupola practice, 2^9, 210 O'Ketfe, John, return flue spark- catcher designed by, 882-384 Old Mine Lehigh coal. 231 Oliphant, F. H., early production of coke by, 238 Osborne Mower and Reaper Co., double spout at the plant of, 315, 316 Oval tuyere, 47 Oyster shells, use of, as flux, 265 PARIS, Daniel E., & Co., trouble with cupolas in the works of, 19(1-195 Parting sand, 81 Patterns, casting of, 166 Paxson CoUiau cupola, 144-148 reservoir spout ladle, 320, 321 truck and track cupola, 176, 177 Pennsylvania, anthracite coal mines in, 23(', 231 Diamond Drill and Manufactur- ing Co., cupola of, 60, 61 Terry & Co., trouble with cupolas in the works of, 181-189 P^vie cupola, 17, 363-365 Picks for chipping out, 126 Pig bed, 330, 331 iron and old scrap, charging of, 106 scrap, mixing of, 105 charging of, 103 melting of, in the manufac- ture of Bessemer steel, 272 with re-melt scrap, 105 of different grades, charging of, 105 use of limestone in the pro- duction of, 258, 259 moulds, iron, 330 Piqua positive blowers, 428 Pit beneath cupola, 3 Pitch of sand bottom, 84, 85 Poking the tuyeres, 112, 113 Poling iron. 27'o, 271 Portable small cupola, 168-170 Pot furnare. fuel required for, 1 Prop, device for removing, 80 foundation for, 79 Prop, wooden, superstition attached to. 80 Providence Locomotive Works, visit to the plant of, U)b-I98 Putting up the doors, 78-80 RAMP, Herbert M., on a wonder- ful cupola, 251, 255 Ramson & Co., hot-blast cupola at the stove foundry of, 209 Reeder, Chas., & Sons, cupolas in the foundry plant of, 9, 10 Relining and repairing, 133-136 Re melt scrap, melting pig iron with, 105 Renewing a lining, 334 Reservoir cupola, 342 spout ladle, 3l0, 321 Return flue cupola spark-catcher, 382-384 Reverberatory furnace, fuel required for, 1 Reversed T tuyere, 52 Ridgway & Son Co., elevators made by, 310, 311 Root's rotary pressure blowers, 422- 424 Round tuyere, 46 Running a continuous stream, 315- 322 Runways, 308, 309 SAND bottom, 81-86 cutting through of, 84 leakage of, 83-86 making the, 83 pitch or slope of, 84, 85 starting the, 122 mould, wet, explosion of molten iron when poured into, 304, 305 Sash vi-eighis, 276 Scafi'old, 7, 22, 23 location of, 41, 42 oldest way of placing stock upon the, 3t 8 ScaffoMs, fire-proof, 41-44 Schuylkill coal, 231 Scientifically designed cupolas, 337- 378 Scrap and pig iron, mixing of, 105 carrying of, by means of tram- rail, 444 old, and pig iron, charging of, 106 sheet iron, melting of, 277 wet, rusted, explosion of molten iron when brought in contact with, 3n5 Sectional cupola. Keep, 171-173 INDEX. 457 Setni-steel mixture, 165 Seveuty-two hour coke, 244, 245 Shape of tuyeres, 7U, 71 Shapes of cupolas, 2 Shapiag the lining, 128-133 Sharp sand, 81 Shavings for lighting up, 95 Sheet blast tuyere, 49 -iron blast pipes, 395 scrap, melting of, 277 Shells, use of, as flux, 265 Shot iron in slag, 261 Silicon, effect of, on iron, 267, 268 Size of tuyeres, 64, 65 Sizes of cupolas, 2 Skinner Engine Co., explosion at, 306 Slag, boiling or foaming, 331 chilling of. 94 constitution of, 261 fluid, amount of limestone re- quired to produce, 260 hole, 33, 93, 94, 263, 264 front. 94 iron in, 261 removal of, from the spout, 89 tapping of, 19, 107 tendency of, 259, 260 weight of, drawn from a cupola, 260, 261 Slagging, cost of, 264, 265 trouble in, 263, 264 Slope of sand bottom, 84, 85 Small cupola, value of. as a money maker or saver, 164, 165 cupolas, 164-186 cheap movable, 170, 171 management of, 171 of Europe, 178-180 Soapstone for daubing, 127 Sol way coke, 251, 252 Southern R. R. Co., cupola for re- melting alloys in shops of, 279 Space theory of melting, 246 Spangler, Chas., cupola in the foun- drv of, 166-168 Spark arrester, 379-382 catching devices for cupolas, 379- 393 Split brick, 135 Spout, 32, 33, 86-90 action of iron at the, 85 basin, 316 bottom of, 89 cross, 316-318 cutting out of, 89 double, 315, 316 filling ladles at the, 446 greatest strain upon, 88, 89 Spout ladle, 318-320 reservoir, 320, 321 lining, cause of cutting out of, 387 drying the, 91 making up the, 87, 88 materials for, 86 tilting, 446 wet, explosion of iron caused by, 302 Spouts, modern, 86 Stack, 5 casing, 27-29 lining, 39 Standard Colliau cupola furnace, 138- 141 Stationary bottom cupola, 174, 175 Stave cupola, old style, 338-341 Steam, adding of, to blast, 222, 223 experiments with, to produce a moist blast, 216, 217 -hydraulic elevator, 310, 311 -jet cupola. Woodward's, 350-354 cupolas, 369-371 Steel bar for cutting away the bod, 116 pressure blowers, 429, 430 on adjustable bed with combined up- right engine, 430, 431 spring gauge, 406 Stewart's cupola, 365-367 Stock, oldest way of placing the, upon the scaffold, 3(i8 yards, elevated, 313, 314 Stopping in, 120, 121 Storage yard, tramrail over, 442 Stove foundrieSj breakage in, 268 investigation as to the num- ber of cupola men required in, 323-325 sand used for bottom in, 81, 82 -foundry cupolas, tuyeres in, 67, 68 use of small cupola in, 165, 160 Straight Line Engine Co., scaffold in the foundry of, 44 Straw for lighting up, 95 Stream, continuous, running a, 315- 322 Sturtevant blowers, 428, 429 high-pressure blowers, 425-428 Supports for cupolas, 24 Swivel cupolas, 166-168 Syracuse Stove Works, melting sheet of, 295 451 INDEX. ''PABLE giviug height and size of 1 doors, 3) of diameter and area of blast- pipes, 398 showing necessary increase in diameter for different lengths of blast-pipes, o9() Tacony Iron Works, Colliau hot-blast cupola in, 206 Tank or reservoir cupola, 3o4-357 Tanks for mixing irons, 356 Tap bars, support for, 121 hole, 31, 32 appearance of iron at the, 109 closing the, before putting on blast, 110, 111 flow of iron from, 112 forming the, 90 making a, 120 slag chilling in the, 94 holes, locating the, 92, 93 sizes of, 92 Tapping and stopping in, 119-122 bars, 11. 5, 116 ladle, 321, 322 slag 32 Test castings, 1 6o Three rows of tuyeres, 58, 59 Tilting spout, 446 Tin, action of, on iron, 276, 277 blast- pi pes, 395 -plate scrap, cost of melting, 390 loss of metal in melting, 390 melting of, 27-5-279 scrap, experiments in melting, 276 Torch for lighting up, 97, 98 Track runways, 3U9 Tramrail, 442-447 constitution of, 442, 443 Treat, C. A., remarks of, 392 Triangular-shaped tuyere, 41, 54 Trolley track, 442-44f Trucks for removing dump, 124 Truesdale cupola, 16 reducing tuyere, 52, 53 Tuyere area, combined size of, 65 boxes, 14, 34, 71, 72 Blakeney, 50, 51 bottom, 61-64 center blast, 61-64, 159, 160, 412, 413 Chenney, 56 Colliau, 56 Doherty. 48, 49 double, 57, 58 expanded, 47, 48 Tuyere, Greiner, 59, 60 height of, 65-69 holes, 5 horizontal and vertical slot, 51 Knoeppel, 75, 76 Lawrence reducing, 53, 54 Mackenzie, 49, 50 oval, 47 reversed T, 52 round, 46 sheet blast, 49 triangular, 51, 54 Truesdale reducing, 52, 53 water, 54, 55 Whiting, 56 Zippier, 75 Tuyeres, 34-36, 45-76 adjustable, 12, 60, 61 combined area of, 34 connection of blast-pipes with, 399 with belt air-cham- ber, 401, 402 blower, 5 double row of, 19, 20 height of, above sand bottom, 35 high, 389 improvement in, 389 location of, 12 new, 72-76 number of, 34, 69, 70 placing of, 411, 412 poking the, 112, 113 preventing iron from running into, 125 shape of, 70, 71 size of, 46, 47, 64, 65 small, 13 three rows of, 58, -59 to improve the quality of iron, 71 two or more rows of, 36, 37 variation in the height of, 65, 66 Watt, 73, 74 j Two-hour cupola, 14, 15 u NITED States, anthracite coal mines in, 231 Navy Yard, Washing- ton, D. C, cupola for melting alloys at, 279 T 70ISIN'S cupola, 348-350 WARMING up a cupola, 196-198 Waste heat, 221 utilization of, 28 INDEX. 459 Water, adding of, to blast, 222, 223 gauge, 406 tuyere, 54, oo Watt cupola tuyere, 73, 74 Weather and the output of the cupola, 217-222 West, Thos. D., large cupola, 159-161 on bottom tuyere, 63 Wheelbarrow runways, 308, 309 Whiting cupola, 148-150 tuyere, 56 Wire screen charging door, inde- structible, 147, 148 Wood and coal, bad melting caused by. 198, 199 for lighting up, 95 Wooden blast-pipes, 395 Woodward's steam-jet cupola, 350- 354 y IPPI^ER tuyere, 75 REDUCE YOUR COSTS witli llie Newten. A vapid, econcMiiical, practical cupola. Not cheap but a money saver. Hun- (irefis are usiiic; the Standard Sizes i diameter of shell! : 30" 36" 42" 48" 54" 60" 66" 72 ' 78" 84" 90 ' 96" 108" Average Capacities per Hour in Tons: 124 5 6 8 10 12 13 16 19 22 28 We make a complete line of Modern Foundry Machinery. Catalogues ? NortHern Engineering WorKs, 30 chene st. DETROIT. MICH ICRANESl •' You will search in vjiin for a lietier crane ' than our 1 ype E Electric. Enclosed Gearing; Capped Bronze Bearings ; no Gearing overhung; Perfect Foundry Control ; large safety factor; Best Electric Equip- ment. All capacities and sizes. We also make hand and pneumatic ciaiies. Catakigue free. Northern Engineering Works, 30 chenest. BRANNT'S METALLIC ALLOYS. Third Edition, Thoroughly Revised and Enlarged. PUBLISHED APRIL 17, 1908. the: meztallic allovs. A Practical Guide for the Manufacture of all Kinds of Alloys, Amalgams, and Solders used by Metal- Workers ; together With their Chemical and Physical Properties and their Application In the Arts and the Industries ; With an Appendix on the Coloring of Alloys and the Recovery of Waste Metals. Edited by 'William T. Brannt. Illustrated by 45 Engravings. Third Edition, thoroughly Revised and Enlarged. 577 pages, 8vo. 4^ Price SS.OO, free of postage to any address in the world. CONTENTS.— Chapter I. Introduction. II. Physical and Chemical Relations of the Metals. III. Special Properties of ihe Metals. IV. General Properties of Alloys. V. Preparation of Alloys in General. VI. Copper Alloys. VII. Copper-Tin Alloys. VIII. Alloys of Copper with Other Metals. IX. Tin Alloys. X. Nickel Alloys. XI. Aluminium Allovs. XII. Lead Alloys. XIII. Cadmium /Mloys XIV. Bismuth Alloys. XV. Iron Alloys (Alloy Steels). XVI. Silver Alloys XVII. Gold Alloys. XVIII. Alloys of Plat- inum and Platinum Metals. XIX. Alloys of Mercury and Other Metals, or Amalgams, XX Miscellaneous Alloys. XXI. Soldeis and Soldefmg. XXII. Determination of the Constituents of Metallic Alloys, of the Impuriti s of the Technically Most Important Metals, etc. Appendix.— Coloring of Alloys. Recovery of Waste Metals. 4®^ An illustrated circular of 6 pages quarto, giving the full Table of Contents of this im- />oi tant book, ivill be sent free of postage to any one in any part afthe world zvho will furnish Jus address. 4®= The above or any of our books sent by mail, free of postage, at ihe publication price, to any address in the world. HEI^RY CAREY BAIRD & CO., INDUSTRIAL PUBLISHERS, BOOKSELLERS AND IMPORTERS, 810 Walnut St., Pliilartelpliia, Pa., U. S. A. WILLIAM SELLERS h CO., Incorp., PHILADELPHIA. MODERN MACHINE TOOLS. Centrifugal Sand Mixing MacHine For rapidly, thoroughly and evenly mixing all kinds of foundry sand. .'. .'. .". .". .*. EFFECTIVE. ECOMOMICJU. CRANES, SHAFTING/INJECTORS, ETC. O^T-A-XiOO-XJE OF pmtM and pcienMfic Boolj^ PUBLISHED BY Henry Carey Baird & Co. INDUSTRIAL PUBLISHERS, BOOKSELLERS AND IMPORTERS. 810 Walnut Street, Philadelphia. . torts, Architectural Terra-Cotta, Sewer Pipe, Drain Tile, Glazed and Unglazed Roofing Tile, Art Tile, Mosaics, and Imitation of Intar.sia or Inlaid Surfaces. Comprising every product of Clay employed in Architecture, Engineering, and the Blast Furnace. With a Detailed Description of tlie Different Clays employed, the Most Modern Machinery, Tools, and Kilns used, and the Processes for Handling, Disintegrating, Tempering, and Moulding the Clay into Shape, Dry- ing, Setting, and Burning. By Charles Thomas Davis. Third Edi- tion. Revised and in great part rewritten. Illu.'-trated by 261 engravings. 662 pages ....... ^20.00 DAVIS. — A Treatise on Steam-Boiler Incrustation and Meth- ods for Preventing Corrosion and the Formation of Scale: By Charles T. Davis. Illustrated by 65 engravings. 8vo. DAVIS. — The Manufacture of Paper: Being a Description of the various Processes for the Fabrication, ('oloring and Finishing of every kind of Paper, Including the Dif- ferent Raw Materials and the Methods for Determining their Values, the Tools, Machines and Practical Details connected with an intelli- gent and a piolitable prosecution of the art, with special reference to the best American Practice. To which are added a History of Pa- per, complete Lists of Paper-Making Materials, List of Anu-rican Machines, Tools and Processes used in treating the Raw Materials, and in Making, Coloring and Finishing Paper. By Charles T. Davis. Illustrated by 156 engravings. 608 pages, Svo. ;^6.oo DAVIS. — The Manufacture of Leather: Being a Description of all the Processes for the Tanning and Tawing with Bark, Extracts, Chrome and all Modern Tannages in General Use, and the Currying, Finishing and Dyeing of Every Kinii of Leaiher; Including the Various Raw Materials, the Tools, Machines, and all Details of Importance Connected with an Intellit;ent and Pioiiiable Prosecution of the Art, with Special Reference to the Best American Practice. To which aie added Lists of American Patents ( 1884-1897) for Materials, Processes, Tools and Machines for Tanning, Currying, etc. By Charles Thomas Davis. Second Edition, Revised, and in great part Rewritten. Illustrated by 147 engravings and 14 Sam- ples of Quebracho Tanned and Aniline Dyed Leathers. Svo, cloth, 712 pages. Price $12.50 DAWIDOWSKY— BRANNT.— A Practical Treatise on the Raw Materials and Fabrication of Glue, Gelatine, Gelatine Veneers and Foils, Isinglass, Cements, Pastes, Mucilages, etc. : Eased upon Actual Experience. By F. Dawidowsky, Technical Chemist. Translated from the German, with extensive additions, including a description of the most Recent American Processes, hy William T. Brannt. 2d revised edition, 350 pages. (1905.) Price Jlj.oo DE GRAFF.— The Geometrical Stair-Builders' Guide: being a Plain Practical System of Hand-Railing, embracing all ita necessary Details, and Geometrically Illustrated by twenty-tw.o Stee! Engravings; together with the use of tlie most approved pnnciple. nf Practical Geometry By Simon De Graff. Architeict (Scan... j HENRY CAREY BAIRD & CO.'S CATALOGUE. l\ DE KONINCK— DIETZ.— A Practical Manual of Chemical Analysis and Assaying : As applied to the Manufacture of Iron from its Ores, and to Cast Iron, Wrought Iron, and Steel, as found in Commerce. By L. L. Dh KoNlNCK, Dr. Sc, and E. Dietz, Engineer. Edited with Notes, by Robert Mallet, F. R. S., F. S. G., M. I. C. E., etc. America^ Edition, Edited with Notes and an Appendix on Iron Ores, by A. A. Fesquet, Chemist and Engineer. lamo. . . . ;^i.oo DUNCAN.— Practical Surveyor's Guide: Containing the necessary information to make any person of com) mon capacity, a finished land surveyor without the aid of a teacher. By Andrew Duncan. Revised. 72 engravings, 214pp. i2mo. $i.So DUPLAIS. — A Treatise on the Manufacture and Distillation of Alcoholic Liquors : Comprising Accurate and Complete Details in Regard to Alcohol from Wine, Molasses, Beets, Grain, Rice, Potatoes, Sorghum, Aspho del. Fruits, etc.; with the Distillation and Rectification of Brandy Whiskey, Rum, Gin, Swiss Absinthe, etc., the Preparation of Aro- matic Waters, Volatile Oils or Essences, Sugars, Syrups, Aromatic Tinctures, Liqueurs, Cordial Wines, Effervescing Wines, etc., tlw Ageing of Brandy and the improvement of Spirits, with Copious Directions and Tables for Testing and Reducing Sjiirituous Liquors, etc>« etc. Translated and Edited from the French of MM. DuPI.AIS, By M. McKennie, M. D. Illustrated 743 pp. 8vo. $15.00 OYER AND COLOR-MAKER'S COM PANION : Containing upwards of two hundred Receipts for making Colors, OQ the most approved principles, for all the various styles and fabrics novf in evi.stence ; with the Scouring Process, and plain Directions for Preparing, Washing-oft', and Finisliing the Goods. i2mo. $1 OO EIDHERR. — The Techno-Chemical Guide to Distillation: A Hand-Book for the Manufacture of Alcohul ami Alcoholic Liquors, including the Preparation of Malt and Compressed Yeast. Edited from tiie German of Ed. Eidherr. EDWARDS. — A Catechism of the Marine Steam-Engine, For the use of Engineers, Firemen, and Mechanics. A Practical Work for Practic.nl Men. By Emory Edwards, Mechanical Engi- neer. Illustrated by sixty-three Engravings, including examples of the most modern Engines. Third edition, thoroughly revised, with much addition.il mattfr. I2mo. 414 jiages . . $2 OO SDWARDS. — Modern American Locomotive Engines, Their Design, Construction and Management. By Emory EdwarDS. Illustrated i2mo $2.00 EDWARDS.— The American Steam Engineer: Theoretical and Practical, with examples of the late^-. and most ap- proved American practice in the design and construction of Steam Engipes and Boilers. For the use of engineers, machinists, boiler- t»»'- gineer, together with Numerous Valuable Rules and Examples. By W. Griswold. i2mo., tucks ' $1.50 ORUNER. — Studies of Blast Furnace Phenomena: By M. L. Gruner, President of the General Council of Mines o" France, and lately Professor of Metallurgy at the Ecole des Mine-. Translated, with the author's sanction, with an appendix, by L. D B. Gordon, F. R. S. E., F. G. S. 8vo. . . . ^2. 50 Hand-Book of Useful Tabl«s for the Lumberman, Farmet and Mechanic: Containing Accurate Tables of Logs Reduced to Inch Board Meas- ure, Plank, Scantling and Timber Measure; Wages and Rent, by Week or Month; Capacity of Granaries, Bins and Cisterns; Land Measure, Interest Tables, with Directions for Finding the Interest on any sum at 4, 5, 6, 7 and 8 per cent., and many other Useful Tables 32 mo., boards. lS6 pages ...... .25 HASERICK.— The Secrets of the Art of Dyeing Wool, Cotton and Linen, Including Bleach'irg and Coloring Wool and Cotton Hosiery and Random Yarns. A Treatise based on Economy and Practice. B^' E. C. Haserick. Illustrated by 323 Dyed Patterns of the Yarm or Fabrics. 8"o. ........ j?5.00 HATS AND FELTING: A Practical Treatise on their Manufacture. By a Practical Hatter, Illustrated by Drawings of Machinery, etc. 8vo. . . ^i.oo HERMANN. — Painting oh Glass and Porcelain, and Enamel Painting: A Complete Introduction to the Preparation of all the Colors and Fluxes Used for Painting on Glass, Porcelain, Enamel, Faience and Stoneware, the Color Pastes and Colored Glasses, together with t Minute Description ol the Firing ot Colors and Enamels, on th« Basis of Personal Practical Experience of the Art up to Date. 18 illustrations. Second edition. ..... #4.00 HAUPT. — Street Railway Motors: With Descriptions and Cost of Plants and Operation of the Various Systems now in Use. isr"* , . . . lS!i-75 HENRY CAREY BAIRD & CO.'S CATALOGUE. 15 HAUPT. — A Manual of Engineering Specifications and Con* tracts. By Lewis M. Haupt, C. E. Illustrated with numerous maps. 328pp. 8vo ;83 00 HAUPT. — The Topographer, His Instruments and Methods. By Lewis M. Haupt, A. M., C. E. Illustrated with numerous plates, maps and engravings. 247 pp. 8vo. . . . ^3-00 HUGHES. — American Miller and Millwright's Assistant: By William Carter Hughes. i2mo ^1.50 HULME. — Worked Examination Questions in Plane Gecrnet • rical Drawing : For the Use of Candidates for the Royal Military Academy, Wool- wich; the Royal Military College, Sandhurst ; the Indian Civil En- gineering College, Cooper's Hill ; Indian Public Works and Tele- graph Departments; Royal Marine Light Infantry; the Oxford and Cambridge Local Examinations, etc. By F. Edward Hulme, F. L. S., F. S. A., Art-Master Marlborough College. Illustrated by 300 examples. Small quarto . . . . . - Si 00 JEK VIS. —Railroad Property: A Treatise on the Construction and Management of Railways; designed to afford useful knowledge, in the popular style, to tha holders of this class of property ; as well as Railway Managers, fjffi. cers, ar.d Agents. By JOHN B. Jervis, late Civil Engineer of the Hudson River Railroad, Croton Aqueduct, etc. i2mo., cloth $i.f;o KEENE.— A Hand-Book of Practical Gauging: For the Use of Beginners, to which is added a Chapter on Distilla- tion, describing the process in operation at the Custom- House for ascertaining the Strength of Wines. By James B. Keene, of H. M. Customs. 8vo. $1 oc KELLEY.— Speeches, Addresses, and Letters on Industrial and Financial Questions : By Hon. William D. Kelley, M. C. 544 pages, 8vo. . S2.50 KOENIG.— Chemistry Simplified: A Course of Lectures on the Non-Metals Based upon the Natural Evolution of Chemistry. Designed Primarily for Engineers. By George Augustus Koenig, Ph.D., A.M., E. M., Professor of Chemistry, Michigan College of Mines, Houghton. Illustrated by 103 Original Drawings. 449 pp i2mo., (1906). . ^2.25 KEMLO.— Watch-Repairer's Hand-Book : Being a Complete Guide to the Young Beginner, in Taking Apart. Putting Together, and Thoroughly Cleaning the English Lever and other Foreign Watches, and all American Watches. By F. Kemlo, •itactical Watchmaker. With Illustrations. i2mo. $J-2$ t6 HENRY CAREY BAIRD & CO.'S CATALOGUE. KENTISH.— A Treatise on a Box of Instruments, And the Slide Ruie ; with the Theory of Trigonometry and Logs rithms, including Practical Geometry, Surveying, Measuring of Tim. ber, Cask and Malt Gauging, Heights, and Distances. By Thoma' Kentish. In one volume. i2mo. . . . . ^JSl.OC KERL.— The Assayer's ManuaL- An Abridged Treatise on the Docimastic Examination of Ores, and Furnace and other Artitici .1 Products. By Bruno Kerl, Professor in the Royal School of Mines. Translated from the German by WiLi-iAM T. Brannt. Second American edition, edited with Ex- tensive Additions by F. LvNWOon Garrison, Mem.ber of the American Institute of Mining Engineers, etc. Illustrated hy 87 en- gravings. 8vo. (Third Edition in preparation. ) KICK. -Flour Manufacture . A Treatise on Milling Science and Practice. By Frederick Kick Imperial Regierungsrnth, Professor of Mechanical Technology in tlu imperial German Polytechnic Institute, Prague. Translated from the second enlarged and revised edition with supplement iiy H. H P. PoWLES, Assoc. Memb Institution of Civil Engineers. Illustrated with 28 Plaips, and 167 Wood-cuts. 367 pages. 8vo. . ;^io.oO RINGZETT.— The History, Products, and Processes of tho Alkali Trade : including the most Recent Improvements. By Chables Thomas yivr.7F.Tr Co"sn1iin'; Chemist. With 23 illustrations. 8vo. i^2.50 KIRK. — The Cupola Furnace : A Practical ireatise on the i Onstruction and Management of Foundry Cupolas. By Edward Kirk, Practical Moulder and Melter, Con- sulting Expert in Melting. Illustrated by 78 engravings. Second Edition, revised and enlarged. 450 pages. 8vo. 1903. ^3-50 LANDRIN.— A Treatise on Steel: Cumprising its Theory, Metallurgy, Properties, Practical Working, and iJse. By M. H. C. Landrin, Jr. From the French, by A. A, Fesquet. i2mo $2.sc LANGBEIN.— A Complete Treatise on the Electro-Deposl tion of Metals : Computing Electro-Plating and Galvanoplastic Operations, the De- position of Metals by the Contact and Immersion Processes, the Color- ing of Metals, the Methods of Grinding and Polishing, as well a? Description of the Voltaic Cells, Dynamo-Electric Machines, Ther- mopyles, and of the Materials and Processes Used in Every Depart- ment of the Art. Translated from tlie Fifth German Edition ot Dr. George Langbein, Proprietor of a Manufactory for Chemical Products, Machines, Apparatus and Utensils for Electro- Platers, and of an Electro-Plating Establishment in Leipzig. With Additions by William T. Brannt, Editoi of ''The Techno-Chemical Receipt Book." Sixth Edition, Revised and Enlarged. Illustrated by 163 Engravings, 8vo , 725 pages (1909) . . . . . ^4 00 LEHNER.— The Manufacture of Ink: Comprising the Raw Materials, and the Preparation of W«-;ting, Copying and Hekiograph Inks, Safety Inks, Ink Extracts and Pow- ders, etc. Translated from the German of SiGMUND Lehner, with additions by William T. Brannt, Illustrated. i2mo. ia.'oo HENRY CAREY BAIRD & CO.'S CATALOGUE 17 *»— " ' . — ■ ~— — - — ■ L.ARKIN. — The Praciicai Brass and Iron Founder's Guide : A Concise Treatise on Brass Founding, Moulding, the Metals and their Alloys, etc.; lo vvnich are added Recent Improvements in the Manufacture of Iron, Steel by the Bessemer Process, etc., etc. Bj James Larkin, late Conductor of the Brass Foundry Department ii keany, Neafie & Co.'s Penn Works, Philadelphia. New editions revised, with extensive additions. 414 pages. i2mo. . S2.50 LEROUX.— A Practical Treatise on the Manufacture of Worsteds and Carded Yarns : Comprising Practical Mechanics, with Rules and Calculations applied to Spinning; Sorting, Cleaning, and Scouring Wools; the Englisk and French Methods of Combing, Drawing, and Spinning Worsteds, and Manufacturing Carded Yarns. Translated from the French of Charles Leroux, Mechanical Engineer and Superintendent of a Spinning-Mill, by HoRATio Paine, M. D., and A. A. Fesquet, Chemist and Engineer. Illustrated by twelve large Plates. To whicb is added an Appendix, containing Extracts from the Reports of the International Jury, and of the Artisans selected by the Committe* appointed by the Council of the Society of Arts, London, on Woolet and Worsted Machinery and Fabrics, as exhibited in the Paris Uni- versal Exposition, 1867. 8vo. 54-00 1-EFFEL.— The Construction of Mill-Dams : Comprising also the Building of Race and Reservoir Embankments and Head-Gates, the Measurement of Streams, Gauging of Water Supply, etc. By James Leffel & Co. Illustrated by 58 engravings Svo. (Scarce.) LESLIE.— Complete Cookery: Directions for Cookery in its Various Branches. By Miss Leslie. Sixtieth thousand. Thoroughly revised, with the addition of New Receipts. i2mo. ... . 5' !"> LE VAN. — The Steam Engine and the Indicator: Their Origin and Progressive Development; including the Mu.-t Recent Examples of Steam and Gas Motors, together with the liuii cator, its Principles, its Utility, and its Application. By William Barnet Le Van. Illustrated by 205 Engravings, chi;?fly of Indi cator-Cards. 469 pp. 8vo . ^2.00 LIEBER.— Assayer's Guide : Or, Practical Directions to Assayers, Miners, and Smelters, for the Tests and Assays, by Heat and by Wet Processes, for the Ores of a'l 0/ principal Metals, of Gold and Silver Coins aad Alloys, and of Coal, etc. By Oscar M. Lieber. Revised. 283 pp. I2mr.. ^1.50 f^ockwood's Dictionary of Terms : Used in the Practice of Mechanical Engineering, embracing those Current in the Drawing Office, Pattern Shop, Foundry, Fitting, Turn- ing, Smith's and Boiler Shops, etc., etc., comprising upwards of Six Thousand Definitions. Edited by a Foreman Pattern Maker, authof jf " Patterr Making." 417 pp. l2mo. . . . $3.75 l8 HENRY CAREY BAlRD & CO.'S CATALOGUE. LUKIN.— The Lathe and Its Uses: Or Instruciion in tlie Art of Turning Wood and Metal. Including a Description ol the Most Modern Appliances for the Ornamentation of Plane and Curved Surfaces, an Entirely Novl'I P^orm of Latiie for Eccentric and Rose-Engine Turning; A Lathe and Planing Macliine Combined; and Other Valuable Matter Relating to the Art. Illustrated by 462 engravings. Seventh edition. 315 pages. Svo #4.35 HAIN and BROWN.— Questions on Subjects Connected with the Marine Steam-Engine : And Examination Papers; with Hints for their Solution. By Thomas J. Main, Professor of Mathematics, Royal "Caval College, and Thomas Brown, Chief Engineer, R. N. i2mo., cloth . ;^i.oo MAIN and BROWN. — The Indicator and Dynamometer: With their Practical Applications to the Steam-Engine. By Thomas J. Main, M. A. F. R., Ass't S. Professor Royal Naval College, Portsmouth, and Thomas Brown, Assoc. Inst. C. E., Chief Engineer R. N., attached to the R. N. College. Illustrated. Svo. . MAIN and BROWN.— The Marine Steam-Engine. By Thomas J. Main, F. R. Ass't S. Mathematical Professor nt the Royal Naval College, Portsmouth, and Thomas Brown, Assoc. Inst. C. E., Chief Engineer R. N. Attached to the Royal Naval College. With numerous illustrations. Svo. MAKINS.— A Manual of Metallurgy: By George Hogarth Makins. 100 engravings. Second edition rewritten and much enlarged. i2mo. 592 pages vffARTIN.— Screw-Cutting Tables, for the Use of Mechanic*) Engineers : Showing the Proper Arrangement of tVheels for Cutting the Threads of Screws of any Requued Pitch ; with a Table for Making the Uni versal Gas Pipe Thread and Taps. By W. A. Martin, Engineer. Svo. .<;o M ICHELL.- Mine Drainage : Being a Complete and Practical Treatise on Direct-Acting Under mund Steam Pumping Machinery. With a Description of a largt nvmber of the best known Engines, their General Utility and Ihe Special Sphere of their Action, the Mode of their Application, and their Merits compared with other Pumping Mnchinery. By STEPHEN MiCHElX. Illuslrated by 247 engravings. 8vo., 369 pages. 11250 MOLESWORTH — Pocket-Book of Useful Formulae and Memoranda for Civil and Mechanical Engineers. By Guilford L. Molesworth, Member of the Institution of Civil Engineers, Chief Resident Engineer of the Ceylon Railway. Full- bound in Pocket-book form . . c - . . Jl 00 ilENRY CAREY Bx\IRD & CO.'S CATALUGUIi, ^9 MOORB.— The Universal Assistant and the Complete Wl chanic ; Containing over one million Industrial Facts, Calculations, Receiptfc. Processes, Trades Secrets, Rules, Business Forms, Legal Items, Etc., in every occupation, from the Household to the Manufactory. B| R. MRE. Illustrated by 500 Engravings. i2mo. . $2.yi MORRIS, — Easy Rules for the Measurement of Earthworks: By means of the Prismoidal Formjla, Illustrated with Numerour VVoed-Cuts, Problems, and Examples, and cunc'.udeti by an Exten sive Table for finding the Solidity in cubic yards from Mean Areas, The whole being adapted for convenient use by Engineers, Surveyors^ Contractors, and others needing Correct Measurements of Earthwork. By Elwood Morris, C. E. 8vo. . . . . . $i.$9 MAUCHLINE.— The Mine Foreman's Hand-Book Of Practical and Theoretical I-.fonnation on the Opening, Ventl lating, and Working of Collieries. Questions and Answers on Prac. tical and Theoretical Coal Mining. Designed to Assist Students and Others in Passing Examinations for Mine Foremanships. By Robert Mauchline. 3d Edition. Thoroughly Revised and En- larged by F. Ernest Brackett. 134 engravings, 8vo. 378 pages. (1905) . $3.75 NAPIER. — A System of Chemistry Applied to Dyeing. By James Napier, F. C. S. A New and Thoroughly Revised Edi- tion. Completely brought up to the present state of the Science, including the Chemistry of Coal Tar Colors, by A. A. Fesquet, Chemist and Engineer. With an Ap]3endix 0,1 Dyeing and Calico Printing, as shown at the Universal Exposition, Paris, 1867. Illus trated. 8vo. 422 pages ....... $2.50 NEVILLE.— Hydraulic Tables, Coefficients, and FoimuI?e, fo' finding the Discharge of Water from Orifices, Notches Weirs, Pipes, and Rivers : Tiiird Edition, with Additions, consisting of New Formuise for tht >ischarge from Tidal and Flood Sluices and Siphons; general infor nation on Rainfall, Catchment-Basins, Drainage, Sewerage, Wa.e» Supply for Towns and Mill Power Bv Tohn Nevii.i.k. C. E. M P I. A. ; Fellow of the Royal Geological Society of Ireland. ThicJ l2mo. ........ Si:arce JEW^BERY.— Gleanings from Ornamental Art of every style : Drawn from Examples in the British, South Kensington, Indian, Crystal Palace, and other Museums, the Exhibitions of 1851 and 1862, and the best English and Foreign works. In a series of loO exquisitely drawn F'lates, containing many hundred examples. By Robert Newberv. 410. ...... (Scaiccj NICHOLLS. —The Theoretical and Practical Boiler-Maker zn4 Engineer's Reference Book: Containing a variety of Useful Information for Employers of Lat^r foremen a\d Workina; Boiler-Makers Iroo, Copper, and Tinsmith* 20 HENRY CAREY BAIRD & CO.'S CAl'ALOGUE. IkaDghtsmen, Engineers, the General Steam-using Public, and for the Use of Science Schools and Classes. By SAMUEL NiCHOL.'.s. Illu» trated by sixteen plates, i2mo. ..... $2.^c- ..NICHOLSON.— A Manual of the Art of Bookbinding -. Containing full instructions in the different Branches of Forwarding^ Gilding, and Finishing. Also, the Art of Marbling Book-edges and Paper. By James B. NICHOLSON. Illustrated. l2mo., cloth $2.25. NICOLLS.— The Railway Builder: A Hand-Book for Estimating the Probable Cost of American Rail* way Construction and Equipment. By WiLLiAM J. NicoLLS, Civil Engineer. Illustrated, full bound, pocket-book form . Scarce NORMANDY. — The Commercial Handbook of Chemical An»^ alysis : Or Practical Instructions for the Determination of the Intrinsic oi Commercial Value of Substances used in Manufactures, in Trades, and in the Arts. By A. Normandy. New Edition, Enlarged, and to a great extent rewritten. By Henry M. Noad, Ph.D., F.R.S.. thick i2mo. . Scarce NORRIS. — A Handbook fcr Locomotive Engineers and Ma chinists : Comprising the Proportions and Calculations for Constructing Loco motives; Manner of Setting Valves; Tables of Squares, Cubes, Areas^ etc., etc. By Septimus Norris, M. E. New edition. Illustrated, J2mo 5»-5c NYSTROM. — A New Treatise on Elements of Mechanics : Establishing Strict Precision in the Meaning of Dynamical Terms accorrpanied with an Appendix on Duodenal Arithmetic and Me trology. By John W. Nystrom, C. E. Illustrated. 8vo. NYSTROM.— On Technological Education and the Construc- tion of Ships and Screw Propellers : For Naval and Marine Engineers. By John V/. Nystrom, l^i. Acting Chief Engineer, U. S. N. Second edition, revised, with addi tional matter. Illustrated by seven engravings. i2mo. . $1.2^ O'NEILL. — A Dictionary of Dyeing and Calico Printing: Containing a brief account of all the Substances and PiocessesJ^. C use in the Art of Dyeing and Printing Textile Fabrics ; with Practrc^ Receipts and Scientific Information. By Charles O'Neill, Anal)" tical Chemist. To which is added an Essay on Coal Tar Colors ano their application to Dyeing and Calico Printing. By A. A. Fesquet Chemist and Engineer. With an appendix on Dyeing and Calic'> Printing, as shown at the Universal Exposition, Paris, 1867- 8vo.. 491 pages . . $2.00 ORTON. — Underground Treasures-. How and Where to Find Them. A Key for the Ready Determination I 25 frlEiNkV CAKtY ii/vlKij ^^ c^. cs k,. . i . > t^vjv^ UE. 25 SMITH— Parks and Pleasure-Grounds : Or Practical Notes on Country Residences, Villas, Public Parks, and Gardens. By Charles H. J. Smith, Landscape Gardener and Garden Architect, etc., etc. l2mo. .... $2.00 SMITH.— The Dyer's Instructor: Comprising Practical Inst<-uctions in the Art of Dyeing Silk, Cotton, Wool, and Worsted, and Woolen Goods; containing nearly 800 Receipts. To which is added a Treatise on the Art of Padding; and t'le Printing of Silk Warps, Skeins, and Handkerchiefs, and the virious Mordants and Colors for the different styles of such work. :;/ David S.MITH, Pattern Dver. i2mo. . . . $1.00 8 /lYTH.— A Rudimentary Treatise on Coal and Coal-Mining. By Warrington \V. Smyth, M. A., F. R. G., President R. G. S. of Cornwall. Fifth edition, revised and corrected. With fiumer* ous illustrations. l2mo. ...... ^^1.40 SNIVELY.— Tables for Systematic Qualitative Chemical Anal- ysis. By John H. Snively, Phr. D. 8vo. .... $1.00 SNIVELY.— The Elements of Systematic Qualitative vhemical Analysis : A Hand-book for Beginners. By JoHN H. Snively, Phr. D. i6mo. ;^2.oo STOKES. — The Cabinet Maker and Upholsterer's Companion: Comprising the Art of Drawing, as applicable to Cabinet Work; Veneering, Inlaying, and Buhl-Work; the Art of Dyeing and Stain ing Wood, Ivory, Bone, Tortoise-Shell, etc. Directions for Lacker- ing, Japanning, and Virnishing; to make French Polish, Glues Cements, and Compos'.^^ns; with numerous Receipts, useful to work men generally. B'- Stokes. Illustrated. A New Edition, with an Appendix upor .ench Polishing, Staining, Imitating, Varnishing, etc., etc. i2nio ........ ^1.25 STRENGTH AND OTHER PROPERTIES OF METALS; Reports of Experiments on the Strength and other Properties of Metals for Cannon. With a Description of the Machines for Testing Metals, and of the Classification of Cannon in service. By Officer? of the Ordnance Department, U. S. Army. By authority of the Secre- tary of War. Illustrated by 25 large sled plates. Quarto . ^5.00 SULLIVAN. — Protection to Native Industry. By Sir Euward Sullivan, Baronet, author of " Ten Chapters on Social Reforms." 8vo. ....... ^i.oo SHERRATT.— The Elements of Hand-Railing: Simplified and Explained in Concise Problems that are Easily Under- stood. The whole illustrated with Thirty-eight Accurate and Origi- nal Plates, Founded on Geometrical Principles, and Showing how'to Make Rail Without Centre Joiiit.s, Making Better Rail of the Same Material, with Half the LaWor, and Showing How to Lay Out Stairs of all Kinds. By R. J. Shekratt. Folio. . . . ^2.50 26 HENRV CAREY BAIRu & CO.'S CATALOGUE. SYME.— Outlines of an Industrial Science. By David Syme. i2mo, . . ... $2.0C TABLES SHOWING THE WEIGHT OF ROUND, SQUARE, AND FLAT BAR IRON, STEEL, ETC., By Measurement. Clolh ...... 63 THALLNER.— Tool-Steel : A Concise Handbook 011 Tool-Steel in General. Its Treatment In the Operations of Forging, Annealing, Hardening, Tempering, etc., and the Appliances Therefor. By OiTO Thallner, Manager ia Chief of the Tool-Steel Works, Bismarck liiitte, Germany. From the German by WiLLIAM T. BrannT. Illustrated by 69 engravings. 194 pages. 8vo. 1902. |2.oo TEMPLETON. — The Practical Examinator on Steam and thi Steam -Engine: With Instructive References relative thereto, arranged for the Use of Engineers, Students, and others. By WiLLiAM TEMPLETON, En. gineer. i2mo. ....•••. ^i-OO THAUSING.— The Theory and Practice of the Preparation of Malt and the Fabrication of Beer: With especial reference to the Vienna Process of Brewing. Elab- orated from personal experience by JUJ..IUS E. Thausing, Professor at the School for Brewers, and at the Agricultural Institute, Modling, near Vienna. Translated from the German by WiLLlAM T. BrannT, Thoroughly and elaborately edited, with much American matter, and according to the latest and most Scientific Practice, by A. ScHWARZ and Dr. A. H. Bauer. Illustrated by 140 Engravings. 8vo., 815 pages .......... ^10.00 THOMPSON. — Political Economy. With Especial Reference to the Industrial History of Nations : By Robert E. Thompson, M. A., Professor of Social Science in the University of Pennsylvania. i2mo. .... ^1.50 THOMSON.— Freight Charges Calculator: By Andrew Thomson, Freight Agent. 24mo. , . ^1.25 TURNER'S (THE) COMPANION: Containing Instructions in Concentric, Elliptic, and Eccentric Turn- ing; also various Plates of Chucks, Tools, and Instruments; and Directions for using the Eccentric Cutter, Drill, Vertical Cutter, and rrircular Rest; with Patterns and Instructions for working them. l2mo. .......... ^I.OO TURNING : Specimens of Fancy Turning Executed on the Hand or Foot-Lathe : i With Geometric, Oval, and Eccentric Chucks, and Elliptical Cutting Frame. By an Amateur. Illustrated by 30 exquisite Photographs. 4to. . (Scarce.) HENRY CAREY BAIRD & CO.'S CATALOGUE. a; V^AILE.— Galvanized-Iron Cornice-Worker's Manual : Containing Instructions in Laying out the Different Mitres, and Making Patterns for all kinds of Plain and Circular Work. Also Tables of Weights, Areas and Circumferences of Circles, and other Matter calculated to Benefit the Trade. By Charles A. Vaile. Illustrated by twenty-one plates. 410. . . .(Scarce.) VILLE. — On Artificial Manures : Their Chemical Selection and Scientific Application to Agriculture. A series of Lectures given at the Experimental Farm at Vincennes, during 1867 and 1874-75. By M. Georges Ville. Translated and Edited by William Crookes, F. R. S. Illustrated by thirty-one engravinos. 8vo., 450 pages ^6.00 VILLE.— The School of Chemical Manures : Or, Elementary Principles in the Use of Fertilizing Agents. From the French of M. Geo. Ville, by A. A. Fesquet, Chemist and En- gineer. With Illustrations. l2mo. .... ;^l.2^ VOGDES.— The Architect's and Builder's Pocket- Companioo and Price-Book : Consisting of a Shoit but Comprehensive Epitome of Decimals, Duo- decimals, Geometry and Mensuration; with Tables of United Stales Measures, Sizes, Vveights, Strengths, etc., of Iron, Wood, Stone, 3rick, Cement and Concretes, Quantities of Materials in given Sizes and Dimensions of Wood, Brick and Stone; and full and complete Bills of Prices for Carpenter's Work and Painting; also. Rules for Computing and Valuing Brick and Brick Work, Stone Work, Paint- ing, Plastering, with a Vocabulary of Technical Terms, etc. By Frank W. Vogdes, Architect, Indianapolis, Ind. Enlarged, revised, and corrected. In one volume, 368 pages, full-bound, pocket-book form, gilt edges ........ ^2.00 Cloth . . 1.50 VAN CLEVE.— The English and American Mechanic: Com|3risiiig a Collection of Over Three Thousand Receipts, Rules, and Tables, designed for the Use of every Mechanic and Manufac- turer, By B. Frank Van Cleve. Illustrated. 500 pp. i2mo. ^2.00 VAN DER BURG.— School of Painting for the Imitation of Woods and Marbles : A Complete, Practical Treatise on the Art and Craft of Graining and Marbling with the Tools and Appliances. 36 plates. Folio, 12x20 inches. ......... $6.00 WAHNSCHAFFE.— A Guide to the Scientific Examinatioe of Soils : Comprising Select Methods of Mechanical and Chemical A lalysu^ and Physical Investigation. Translated from the German of Dr. F. Wahnschaffe. With additions by William T. Brannt. Illus- trated by 25 engravings. i2mo. 177 pages . . . $l-Sfi IVALTON. — Coal-Mining Described and Illustrated: By Thomas H. Walton, Mining Engineer. Illustrated by 24 Jast^ and elaborate Plates, after .(Xctual Workings and Apparatus. |2.oo 2^ HENRY CAREY BAIRD & CO.'S CATALOC UE. WARE.— The Sugar Beet. Including a History of the Beet Sugar Industry in Europe, Vanetiei of the Sugar Beet, Examination, Soils, Tillage, Seeds and Sowing, Yield and Cost of Cultivation, Harvesting, Transportation, Conserva tion, Feeding Qualities of the Beet and of the Pulp, etc. By Lewh S. Ware, C. E., M. E. Iliustiated by ninety engravings. 8vo. WARN.— The Sheet-Metal Worker's Instructor: For Zinc, Sheet-Iron, Copper, and Tin-Plate Workers, etc. Contain- ing a selection of (jeonietrical Problems ; also. Practical and Simple Rules for Describing the various Patterns required in the different branches of the above Trades. By Reuben H. Warn, Practical Tin- Plate Worker. To which is added an Appendix, containing Instructions lor Boiler-Making, Mensuration of Surfaces and Solids, Rules for Calculating the Weights of different Figures of Iron and Steel, Tables of the Weights of Iron, Steel, etc. Illustrated by thirty- two Plates and 'hirty-seven Wood Engravings. 8vo. . ^^2.50 WARNER.— New Theorems, Tables, and Diagrams, for tht Computation of Earth-work : Designed for the u^e of Engineers in Preliminary and Final Estimates of Students in Engineering, and of Contractors and other non-profes- sional Computers. In two parts, with an Appendix. Parti. A Prac- tical Treatise; Part II. A Theoretical Treatise, and the Appendix, Containing Notes to the Rules and Examples of Part I.; Explana tions of the Construciion nf Scale'^, T.ible>, and Diagrams, and j Treatise upon Equivalent hquare Bases and Equivalent Level Heights By John Warner, A. M., Mining and Mechanical Engineer. Illus- 1 ated by 14 Plates. Svo. ...... $3.00 WILSON. — Carpentry and Joinery : By John Wilson, Lecturer on Building Construction, Carpentry and Joinery, etc., in the Manchester Technical School. Third Edition, with 65 full-page plates, in flexible cover, oblong. . . (Scarce.) WATSON— A Manual of the Hand.Lathe : Comprising Concise Directions for Working Metals of all kinds, Ivory, Bone, and Precious Woods ; Dyeing, Coloring, and French Polishing ; Inlaying by Veneers, and various methods practised to produce Elaborate work with Dispatch, and at Small Expense. By Egbert P. Watson, Author of "The Modern Practice of American Machinists and Engineers " Illustrated by 78 engravings. $1.50 WATSON. — The Modern Practice of American Machinists and Engineers : Including the Construction, Application, and Use of Drills, Lathe Tools, Cutters for Boring Cylinders, and Hollow-work generally, with the most Economical Speed for the same ; the Results verified by . Actual Practice at the Lathe, the Vise, and on the floor. Togethei HENRY CAREY BAIRD & CO.'S CATALOGUE. 29 with Workslinp Management, Economy of Manufacture, the Steam Engine, Boilers, Gears, Belting, etc., etc. By Egbert P. V\ atson. Illustra'ed hy eighty-six engravings. i2mo. . . . $2.50 WATT.— The Art of Soap Making: A Practical Iland-Book of the Manufacture of Hard and Soft Soaps, Toilet Soaps, etc. Fifth Edition, Revised, to which is added an Appendix on Modern Candle Making. By Alexander Watt. 111. I2nio. S3. 00 WEATHERLY.— Treatise on the Art of Boiling Sugar, Crys- tallizing, Lozenge-making, Comfits, Gum Goods, And other processes for Confectionery, including Methods for Manu- facturing every Description of Raw and Refined Sugar Goods. A New and Enlarged Edition, with an Appendix on Cocoa, Chocolate, Chocolate Confections, etc. 196 pages, 1 2mo. (1903) . i^i.So WILL. — Tables of Qualitative Chemical Analysis • With an Introductory Chapter on the Course of /Analysis. By Pro- fessor Heinrich Will, of Giessen, Germany. Third American, from the eleventh German edition. Edited by Charles F. Himes, Pli. D., Professor uf Natural Science, Dickinson College, Carlisle, Pa. 8vo ^1.50 WILLIAMS.— On Heat and Steam : Embracing New Views of Vaporization, Condensation and Explo- sion. By Charles Wye Williams, A. I. C. E. Illustrated. 8vo. J2.50 WILSON — First Principles of Political Economy: Witli Reference to Statesmanship and tiie Progress of Civilization. By Professor W. D. WiLSON, of the Cornell University. A new and revised edition. l2mo. . . . . . . ^I-S^ WILSON. — The Practical Tool-Maker and Designer: A Treatise upon tlie Designing of Tools and Fixtures for Machine Tools and Metal Working Machinery, Comprising Modern Examples of Machines with Fundamental Designs for Tools for the Actual Pro- duction of the work ; Together with Special Reference to a Set of Tools for Machining the Various Parts of a Bicycle. Illustrated by 189 engravings. 1898. ...... $2.50 CONTENTS: Introductory. Chapter I. Modern Tool Room and Equipment. II. Files, Their Use and Abuse. III. Steel and Tempering. IV. Making Jigs. V. Milling Machine Fixtures. VI. Tools and Fixtures fur Screw Machines. Vll. Broaching. VIII. Punches and Dies for Cutting and Drop Press. IX.Toolsfor Hollow-Ware. X. Embossing: Metal, Coin, and Stamped Sheet-Metal Orna- ments. XI. Drop Forging. XII. Solid Drawn Shells or Ferrules ; Cupping or Cutting, and Drawing; Breaking Down Shells. XIII. Annealing, Pickling, and Cleaning, XIV. Tools for Draw Bench. XV. Cutting and Assemblirg Pieces by Means of Ratchet Dial Plates at One Operation. XVI. The Header. XVII Tools for Fox Lathe. XVIII. Suggestions for a Set of Tools for Machining the Various Parts of a Bicycle. XIX. The Plater's Dynamo. XX. Conclusion — With a Few Random Ideas. Appendix. Index. WOODS — Compound Locomotives : By Arthur Tannatt Woods. Second edition, revised and enlarged by David Leonard Barnes, A. M., C. E. 8vo. 330 pp. $3.00 30 HENRY CAREY BAIRD & CO.'S CATALOGUE. WOHLER. — A Hand-Bookof Mineral Analysis: By F. WoHLER, Professor of Chemistry in the University of Gottin- gen. Edited by Henry B. Nason, Professor of Chemistry in the Renssalaer Polytechnic Institute, Troy, New York. Illustrated. i2nio. $2.50 WORSSAM.— On Mechanical Saws: From the Transactions of the Society of Engineers, 1869. By S. W. WoRSSAM, Jr. Illustrated by eighteen large plates. 8vo. $1.50 RECENT ADDITIONS. BRANNT. — Varnishes, Lacquers, Printing Inks and Sealing. Waxes : Their Raw Materials and their Manufacture, to which is added the Art of Varnishing and Lacquering, including the Preparation of Put- ties and of Stains for Wood, Ivory, Bone, Horn, and Leather. By William T. Brannt. Illustrated by 39 Engravings, 338 pages. i2mo ^3.00 BRANNT.— The Practical Dry Cleaner, Scourer, and Gar- ment Dyer : Comprising Dry or Chemical Cleaning; Purification of Benzine; Re- moving Stains or Spotting; Wet Cleaning; Finishing Cleaned Fabrics; Cleaning and Dyeing Furs, Skins, Rugs, and Mats; Cleaning and Dyeing Feathers ; Bleaching and Dyeing Straw Hats ; Cleaning and Dyeing Gloves; Garment Dyeing; Stripping; Analysis of Textile Fabrics. Edited by William T. Brannt, Editor of "The Techno- Chemical Receipt Book." Third Edition, Revised and Enlarged. Illustrated by Twenty-Three Engravings ^2 50 BRANNT.— Petroleum , its History, Origin, Occurrence, Production, Physical and Chemical Constitution, Technology, Examination and Uses; Together with the Occurrence and Uses of Natural Gas. Edited chiefly from the German of Prof. Hans Hoefer and Dr. Alexander Veith, by W'M. T. Brannt. Illustrated by 3 Plates and 284 Engravings. 743 pp. 8vo, #8.50 BRANNT. — A Practical Treatise on the Manufacture of Vine- gar and Acetates, Cider, and Fruit-Wines ; Preservation of Fruits and Vegetables by Canning and Evaporation; Preparation of Fruit-Butters, Jellies, Marmalades, Catchups, Pickles, Mustards, etc. Edited from various sources. By WiLLlAM T. Brannt. Illustrated by 79 Engravings. 479 pp. 8vo. $S-oo BRANNT.— The Metal Worker's Handy-Book of Receipts and Processes : Being a Collection of Chemical Formulas and Practical Manipula- tions for the working of all Metals; including the Decoration and Beautifying of Articles Manufactured therefrom, as well as their Preservation. Edited from various sources. By William T. Brannt. Illustrated. i2mo. I2.50 HENRY CAREY BAIRD & CO.'S CATALOGUE. 31 DEITE. — A Practical Treatise on the Manufacture of Per- fumery : Comprising directions for making all Kinds of Perfumes, Sachet Powders, Fumigating Materials, Dentifrices, Cosmetics, etc., with a full account of the Volatile Oils, Balsams, Resins, and other Natural and Artificial Perfume-substances, including the Manufacture of Fruit Ethers, and tests of their purity. By Dr. C. Deite, as^^isted by L. BoRCHERT, F. Eichbaum, E. Kugler, H. Toeffner, and other experts. From the German, by Wm. T. Brannt. 28 Engrav ings. 358 pages. 8vo. $3*30 EDWARDS. — American Marine Engineer, Theoretical and Practical : With Examples of the latest and most approved American Practice. By Emory Edwards. 85 illustrations. lamo. . . ^2.00 EDWARDS.— 900 Examination Questions and Answers: For Engineers and Firemen (Land and Marine) who desire to ob- tarn a United States Government or State License. Pocket-book form, gilt edge ^^-5° FLEMMING. — Practical Tanning: A Handbook of Modern Processes, Receipts, and Suggestions for the Treatment of Hides, Skins, and Pelts of Every Description. By Lewis A. Flsmming. American Tanner. 472 PP- 8 vo. (1903) ^4.00. POSSELT. — The Jacquard Machine Analysed and Explained: With an Appendix on the Preparation of Jacquard Cards, and Practical Hints to Learners of Jacquard Designing. By E. A. PossELT. With 230 illustrations and numerous diagrams. 127 pp. 4to $300 POSSELT. — Recent Improvements in Textile Machinery, Part III: Processes Required for Converting Wool, Cotton, Silk, from Fibre to Finished Fabric, Covering both Woven and Knit Goods ; Con- struction of the most Modern Improvements in Preparatory Machin- ery, Carding, Combing, Drawing, and Spinning Machinery, Winding, Warping, Slashing Machinery Looms, Machinery for Knit Goods, Dye Stuffs, Chemicals, Soaps, Latest Improved Accessories Relat- ing to Construction and Equipment of Modern Textile Manufactur- ing Plants. By E. A, Possf.lt. Comoletel" Illustrated. 4to. ^7-50 RICH.— Artistic Horse.Shoeing: ^ ,^ ^ ^ . A Practical and Scientific Treatise, givmg Improved Methods of ShoeinP with Special Directions foi Shaping Shoes to Cure Different Disease's of the Foot, and for the Correction of Faulty Action in Trotters By George E, "i'm r.2 Ilhisiu.tions. 153 pa-es ' 2.00 32 HENRY CAREY BAIRD & CO.'S CATALOGUE. RICHARDSON. -Practical Blacksmithing : A Callection of Articles Contributed at Different Times by Skilled Workmen to the columns of " The Blacksmith and Wheelwright," and Covering nearly the Whole Range of Blacksmithing, from the Simplest Job of Work to some of the Most Complex Forgings. Compiled and Edited by M. T. Richardson. Vol.1. 2IO Illiistraiions. 224 pages. i2mo. . . ^Jl.oo Vol. II. 230 Illustrations. 262 pages. l2mo. . , $l.oo Vol. III. 390 Illustrations. 307 pages. i2mo. , , ^Sl.oo Vol. IV. 226 Illustrations. 276 pages. I2mo. , , |i.oo RICHARDSON.'— The Practical Horseshoer; Being a Collection of Articles on Horseshoeing in all its Branches* which have appeared from time to time in the columns of " 1 he Blacksmith and Wheelwright," etc. Compiled and edited by M. T. Richardson. 174 illustrations ^i.oo ROPER. — Instructions and Suggestions for Engineers and Firemen : By Stephen Roper, Engineer. i8mo. Morocco . $2.00 ROPER.— The Steam Boiler: Its Care and Management: By Stephen Roper, Engineer. i2mo., tuck, gilt edges. ;^2.oo ROPER.— The Young Engineer's Own Book: Containing an Explanation of the Principle and Theories on which the Steam Engine as a Prime Mover is Based. By Stephen Roper, Engineer. 160 illustrations, 363 pages. i8mo., tuck . '82. 50 ROSE. — Modern Steam- Engines: An Elementary Treatise upon the Steam-Engine, written in Plain language ; for Use in the Workshop as well as in the Drawing Office. Giving Full Explanation J of the Construction of Modern Steanv Engines : Including Diagrams showing their Actual operation. To. gether with Complete but Simple Explanations of the operations of Various Kinds of Valves, Valve Motions, and Link Motions, etc., thereby Enabling the Ordinary Engineer to clearly Understand the Principles Involved in their Construction and Use, and to Plot out their Movements upon the Drawing Board. By Joshua Rose. M. E. Illustrated by 422 engravings. Revised. 358 pp. . . ;5!6.oo ROSE.— Steam Boilers: A Practical Treatise on Boiler Construction and Examrnation, for the Use of Practical Boiler Makers, Boiler Users, and Jjispectors; and embracing in plain figures all the calculations necessary in Designing or Classifying Steam Boilers. By Joshua Rose, M. E. Illustrated by 73 engravings. 250 pages. 8vo. .... 152.50 8CHRIBER. — The Complete Carriage and Wagon Painter: A Concise Compendium of the Art of Painting Carriages, Wagons, and Sleighs, embracing Full Directions m all the Various Branches, including Lettering, Scrolhng, Oman;enting, Striping, Varnishing, and Coloring, with numerous Recipes for Mixing Colors. 73 Illus- trations. 177 pp. i2mo. ...... $iJOr 1 AUG 131910 ^M- PS?*''' One copy del. to Cat. Div |:^*S IS ««•.■*. -.-TjmOL