* . i * * * * . . . . .. ... . . * & ; : , ; 3: ... Sº ~. ©º < *, * º § * , , ; ‘. \ # , º, . . . www.s *". # Nº Ö - sº • 3 & y & A” * aft £3. *y *~ , $ , , , , & * ** & ... - ... * ſº & "3 - ... * . . . **... .” .* ºr; ... }, . r; *... " . , , , . . . , *. ºf , ' ' s , . . '? ...# • * . *†, 3. Meilon Institute of Industrial Research and School of . - Specific Industries Smoke Investigation Bulletin No. 8 Some Engineering Phases of Pittsburgh's Smoke Problem University of Pittsburgh Pittsburgh, Pa. 1914 Mellon Institute of Industrial Research and School of Specific Industries Robert Kennedy Duncan, Sc.D Director. Raymond F. Bacon, Ph.D Associate Director. - STAFF OF THE SMOKE INVESTIGATION Raymond C. Benner, Ph.D..........Chief Fellow and Chemist. Joseph A. Beck, LL.B Attorney. A. B. Bellows, B.S Mech. Engineer. W. W. Blair, M.D ...Physician. J. F. Clevenger, M.A. Botanist. B. A. Cohoe, A.B., M.D Physician. E. W. Day, A.M., M.D Physician. S. R. Haythorn, M.D Physician. W. L. Holman, A.B., M.D Physician. Richard Hooker, B.S Architect. C. T. Ingham -Architect. Richard Kiehnel Architect. H. H. Kimball, Ph.D.... Meteorologist. Oskar Klotz, M.D., C.M. Physicia- E. B. Lee ...Architect. C. H. Marcy, A.B Bacteriologist. O. R. McBride, B.S Mech. Engineer. E. H. McClelland, Ph.B Bibliographer. R. T. Miller, Jr., A.B., M.D.--------------------------------------- Surgeon. A. F. Nesbit, B.S., A.M. Elec. Engineer. J. J. O’Connor, Jr., A.B Economist. K. K. Stevens, B.S ....Chemist. A. A. Straub, M.E Mech. Engineer. Carlton Strong Architect. W. W. Strong, Ph.D. Physicist. J. E. Wallace Wallin, Ph.D Psychologist. W. C. White, M.D Physician. Ruth E. Gilchrist Secretary. There is nothing impossible or wonder- ful about the smokeless combustion of even Pittsburgh coal, provided the proper methods are applied and the ordinary precautions taken. : : º º Contents. PAGE. Note * 7 Introduction 8 Summary of conclusions 9 PART I. The history of the smoke nuisance and of smoke abatement in Pitts- burgh PART II. Evidences of the smoke nuisance Study of Pittsburgh’s soot-fall PART III. The contributing causes of the smoke nuisance The coal field.…~~~~~~~~~~~~~~~~~~~~~~~~~~~ The composition of Pittsburgh coal Pittsburgh’s industries The coal consumption of the District Topography of the Pittsburgh District The wind direction and the smoke nuisance....... * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * PART IV. The sources of smoke in the city of Pittsburgh and the Pittsburgh District The business section of the city Manufacturing plants Special furnaces * * * * * * * * * * * * * * * * * * * * * * * * Railroads Steamboats Residence section Miscellaneous services PART V. Mechanical engineering survey of stationary plants e Object of the survey....................…..--------------------------------~~~~~ Methods of collecting data Smoke observations Hand-fired plants The steam jet; its use with hand-fired plants.............................. Results of the survey of hand-fired plants............................ Mechanical stokers Chain-grate stokers * * * * Results of the survey of chain-grate stoker plants.............. Front-feed Stokers * * Results of the survey of front-feed stoker plants.............. Side-feed stokers … … Results of the survey of side-feed stoker plants...... .... .... Underfeed stokers - - - Results of the survey of underfeed stoker plants................ APPENDIX. Appendix I. Prevailing winds Appendix II. Powdered coal ...................................................................... Appendix III. The construction of the Ringleman smoke chart............ Appendix IV. Rules to aid in abating smoke 185 193 FIGURE 11. 12. 13. 14. 15. 16. 17. 18. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 34. 35. Illustrations. PAGE. Map of Pittsburgh and vicinity Frontispiece Soot-fall map of Pittsburgh...................................................... 21 Relief map of Pittsburgh 31 View down the Ohio River when the city was free from Smoke 36 Same view as in Figure 4 on a smoky day............................ 37 View of North Side when the city was free from smoke.... 38 Same view as in Figure 6 on a smoky day........................... 39 View of the “Downtown Section” when the city was free from smoke - 40 Same view as in Figure 8 on a smoky day.............................. 41 View up the Allegheny River when the city was free from smoke 42 Same view as in Figure 10 on a Smoky day................ ........... 43. View in direction of Pennsylvania Station when city was free from Smoke ... 44 Same view as in Figure 12 on a smoky day.......................... 45 View east across the city when it was free from smoke...... 46 Same view as in Figure 14 on a smoky day............................ 47 Shows how industrial plants line the river banks................ 50. Smoky condition in neighborhood of metallurgical furnaces 63 Smoke from locomotive in a residence section of Pittsburgh 69 Steamboat on the Monongahela River ... 79 Dutch oven setting as applied to horizontal return tubular boiler 89 Kent’s wing-wall furnace as applied to Babcock & Wilcox water-tube boiler 90. Wooley furnace applied to Babcock & Wilcox water-tube boiler 91 Usual method of setting horizontal return tubular boiler.... 92 Horizontal return tubular boiler with fire-brick arch over grates and under boiler shell 93 Horizontal return tubular boiler with fire-brick arch over grates --------------------------------------------------------------------------------------- 93 Heine water-tube boiler equipped with Hawley down-draft furnace 94. Chain-grate with short ignition arch as applied to Bab- cock & Wilcox watér-tube boiler ... 111 Chain-grate with short ignition arch as applied to Heine water-tube boiler ... 112 Special setting of chain-grate stoker and Babcock & Wil- cox water-tube boiler 113 Special setting of chain-grate stoker and Babcock & Wil- cox water-tube boiler ... 114 Chain-grate stoker as applied to Wickes vertical water- tube boiler … 115 Chain-grate stoker as applied to Stirling water-tube boiler 116 Detailed construction of Roney Stoker 128 Front-feed Stoker, Roney model, as applied to Babcock & Wilcox water-tube boiler.................................................... 130. Front-feed stoker, Roney model, as applied to Babcock & Wilcox water-tube boiler, Alert type of setting................ 131 PAGE. 36. 37. 38. 39. 40. 41. 42. 43. 45. 47. 48. 49. 50. 51. 52. 53. 54. 55. 56. 57. 58. 59. 61. 62. 63. Front-feed stoker, Roney model, as applied to Heine water-tube boiler • * * * * * * * Front-feed stoker, Roney model, as applied to a Rust vertical water-tube boiler - Front-feed stoker, Roney model, as applied to horizontal return tubular boiler Front-feed stoker, Roney model, as applied to Stirling water-tube boiler Front-feed stoker, Roney model, as applied to large Stirl- ing water-tube boilers Vertical cross section of side-feed stoker, Murphy model Side-feed stoker, Murphy model, as applied to Heine water-tube boiler, flush-front setting Side-feed stoker, Murphy model, as applied to Heine water-tube boiler, extended over setting * Side-feed stoker, Murphy model, as applied to Babcock & Wilcox water-tube boiler, extended over setting.............. Side-feed stoker, Murphy model, as applied to horizontal return tubular boiler, extended front setting.................... Side-feed stoker, Murphy model, as applied to Stirling water-tube boiler Longitudinal section of underfeed stoker, Jones model........ Underfeed Stoker, Jones model, as applied to Babcock & Wilcox water-tube boiler........................................................ Underfeed stoker, Jones model, as applied to Heine water- tube boiler …~~~~~~ Underfeed Stoker, Jones model, as applied to Wickes water-tube boiler Underfeed stoker, Jones model, as applied to a horizontal return tubular boiler - Underfeed Stoker, Jones model, as applied to a Stirling water-tube boiler Underfeed Stoker, Jones model, as applied to a Scotch marine boiler - Cross section of underfeed stoker, Jones model, as applied to a horizontal return tubular boiler Longitudinal section of underfeed stoker, Taylor model.... Underfeed stoker, Taylor model, as applied to a horizontal return tubular boiler Underfeed stoker, Taylor model, as applied to a Babcock & Wilcox water-tube boiler Underfeed stoker, Taylor model, as applied to Heine water-tube boiler Underfeed stoker, Taylor model, as applied to a Stirling boiler …~~~~~~~~~~~~~~~~~~~~~ Underfeed stoker, Taylor model, as applied to Rust water- tube boiler …~~~~~~~~~~~~~~ Underfeed stoker, Jones model, as applied to a furnace for heating forgings. This furnace is equipped with a waste- heat boiler Underfeed stoker, Jones model, as applied to a billet-heat- ing furnace at the plant of the Oil Well Supply Com- pany, Pittsburgh, Pa Ringleman Smoke Chart 132 133 134 135 136 149 151 152 153 154 154 161 16.1 162 163 164 164 165 166 167 167 168 169 170 171 172 173 189 Note. The work on this report was begun in March, 1912, under the direction of Mr. A. B. Bellows. The work was outlined by him and the field work carried on under his supervision until May, 1913, when he was compelled to resign because of illness. The work was then taken up by Mr. A. A. Straub, who had joined the Engineering Staff of the Investigation in December, 1912. The material was assembled and the report was written, for the most part, by him. Mr. Straub remained with the Investigation until June, 1913. All of the field work in connection with the report was done by Mr. O. R. McBride. The outline for the survey of plants in this report is similar to that developed in Bulletin 40 of the United States Bureau of Mines, “The Smokeless Combustion of Coal in Boiler Furnaces,” by D. T. Randall and H. W. Weeks. The authors of this report are indebted to these men. Acknowledgment is made to Mr. A. F. Nesbit for revising and reviewing the report. The drawings for the line cuts were kindly furnished by the various boiler, furnace and Stoker companies. The photographs of the city and of the maps were taken by Mr. Harry C. Anderson. No bibliography is appended to this report because it is expected that those who receive it either have copies of, or at least, have access to copies of Smoke Investiga- tion, Bulletin No. 2, Bibliography of Smoke and Smoke Prevention. JoHN O’ConnoR, JR. February 23, 1914. Introduction. This report was made with the view, first, to determine the conditions which, existing in the Pittsburgh District, account for so much smoke in the District and, second, to describe the methods of furnace construction and the existing mechanical or other devices, the employment of many of which aids materially in securing more perfect combustion of fuel and lessens the amount of smoke pro- duced. The smoke nuisance is no new problem in Pittsburgh. It has been a sore spot since the very beginning of the city. The city, in the minds of some, seemed to have thrived on smoke and it came, in time, to be a symbol of prosperity. It is only at this late day, in the light of an ever growing civic consciousness, that the city is coming to realize that the smoke nuisance is the greatest handi- cap with which it has to contend. Pittsburgh’s smoke problem is unique in many ways and there are extenuating circumstances connected with it. It is well known that the District is located in the heart of the bituminous coal fields, the coal from which, being very rich in volatile matter, is difficult to burn with- Out Smoke. The industries of the District use more bitum- inous coal than any other district of like size in the world. Pittsburgh’s topography, which bears the brunt of so many of Pittsburgh's evils, while no cause of the smoke nuisance, intensifies and prolongs it. Pittsburgh's irreg- ular topography confines the smoke in “pockets” so that it cannot be readily carried away by the winds. A study of the topography will reveal the fact that the non-pro- duction of smoke is the only solution of Pittsburgh's Smoke problem. Arguments which are advanced in other cities against the smoke nuisance have not the same value when they are advanced in Pittsburgh. It is so with the argument that smokeless combustion is economical. Efficiency tests of plants and mills may not reveal a very large monetary saving, under the most favorable conditions of operat- ing, when fuel is $1.25 or less per ton. The mechanical engineer has no light task before him, in his attempt to demonstrate conclusively that a redesigning of combus- tion chambers, the proper mixture of air and volatile gases, and the employment of automatic devices for feed- ing the fuel, will result in the greatest economy and at the same time minimize the production of smoke. More than that, it is sad to relate, that the mechanical engineer is seldom called in by the owner of a Pittsburgh plant. The plant owner, as a rule, seeks advice from someone who has this or that apparatus to sell him. The Pitts- burgh District should be the greatest center in the world for combustion engineers. There is a need, but no great demand for them. However, the outlook for smoke abatement in the Pittsburgh District is most hopeful. With the introduc- tion of modern ideas of efficiency, the plant owner will be forced to look, where so few have as yet looked, into the boiler room to see what savings can be affected there. In doing this he will, moreover, be prompted and urged by a sense of duty and responsibility to the community, which is more and more coming to demand that the smoke nuisance be abated as a menace to health, property and the things which make for civic betterment. Summary of Conclusions. That there is a reason for such a report as the present one is evidenced by the fact that when smoke observations were made on the stacks of the one hundred and fifty-two stationary plants, described in this report, about forty per cent. of them were violating one of the most lenient smoke ordinances of any large city of the United States. Fifty per cent. of the stacks of the hand-fired plants and sixty per cent. of the stacks of the front-feed stoker plants were violating the ordinance. The percentages of violations from the other types of stationary plants were small. The two main sources of smoke in the city and district are the manufacturing plants, which include special fur- naces, and the railroads. The amount of smoke made in the business and in the residence sections is relatively small. In the manufacturing plants, on account of the cheap- ness of fuel, slight attention is paid to the efficiency of the boiler plant and little effort is made to prevent smoke in heating or metallurgical furnaces. Because of the condi- tions which prevail in the majority of plants the average boiler efficiency is from fifteen to twenty-five per cent. lower than what it should be. If the necessary changes were made in these plants and the proper care taken, it would not be unreasonable to expect a thirty per cent. decrease in fuel consumption. The next worst offenders to the manufacturing plants, in the emission of smoke, are the railroads. Inasmuch as all outbound locomotives have to ascend heavy grades they make much smoke. However, most of the smoke is made in the yards by shifting engines. There seems to be only one sure cure for this, and that is that they use some fuel which does not produce objectionable smoke as, for exam- ple, coke. Probably, the ultimate solution of the railroad smoke problem is electrification. A strenuous demand for smoke abatement will hasten its coming. A small group of men control the plants which pro- duce at least eighty per cent. of the smoke of the district. The solution of Pittsburgh's smoke problem lies in induc- ing these men to apply the best of modern engineering practice to the combustion of fuel in their plants. There is nothing impossible or wonderful about the smokeless combustion of even Pittsburgh coal, provided the proper methods are applied and the ordinary precautions taken. SOME ENGINEERING PHASES 11. Part I. The History of the Smoke Nuisance and of Smoke Abatement in Pittsburgh. The history of the Smoke Nuisance in Pittsburgh dates from the very beginning of the city. Tradition has it that coal was burned in Fort Duquesne by the French. As this coal was from the Pittsburgh vein, which is so rich in volatile matter, and as it was burned, no doubt, as a great part of it is burned to-day, it is safe to assume that there was black smoke about the Fort even in its earliest days. The Rev. Charles Beatty, who was chap- lain of the English forces which occupied the Fort in 1758, noted that coal was used in the garrison in 1766. In that year, what was known as “Coal Hill,” now Mount Washington, took fire and is said to have burned steadily for sixteen years. A TOWN PROBLEM 110 YEARS AGO. That official cognizance was early taken of the Smoke Nuisance is indicated in the following communi- cation of General Presley Neville, the Burgess of Pitts- burgh, to George Stevenson, the President of Council. The letter is dated June 10, 1804. It reads in part: “The general dissatisfaction which prevails and the frequent complaints which are exhibited, in consequence of the Coal Smoke from many buildings in the Borough, particularly from Smithies and Blacksmith Shops, com- pels me to address you on this occasion. I would be ex- tremely sorry to be in any way the means of subjecting any of our fellow citizens to unnecessary or useless ex- pense, but in this instance not only the comfort, health and in some measure the consequence of the place, but the peace and harmony of the inhabitants, depend upon 12 THE SMOKE INVESTIGATION the speedy measures being adopted to remedy the nuis- ance.” The burgess went on to suggest higher chimneys by which “the Smoke could be voided into free air and car- ried beyond the limits of the Borough.” FIRST CITY LEGISLATION. Although the attention of Pittsburghers was con- stantly called by officials and more especially by visitors, to the evils of the smoke nuisance, no legal regulation was attempted until shortly before 1869. In the digest of the ordinances of Pittsburgh, 1804- 1869, there is recorded the following ordinance: “Section 2344. No bituminous coal or wood shall be used in the engine or any locomotive employed in con- ducting trains upon any railroad.” The code in which this ordinance appears was formu- lated in 1869 so this ordinance was passed, no doubt, shortly before that date. It is said that it has never been expressly repealed or amended. THE COMING OF GAS. There is no reason for believing that this ordinance was very seriously enforced. There are, however, good reasons for believing that Pittsburgh would never have had any smoke abatement agitation, as early as it did, if it had not come to pass that the city was practically freed from smoke by the discovery of natural gas and its utiliza- tion as a fuel. In a report made to the Engineers' Society of Western Pennsylvania in May, 1884, there was this statement: “Smoke and smoked ceilings of Pittsburgh may become things of the past, yet if sold at the price now charged, i. e., 50c per thousand feet, it (natural gas) is much more costly than coal.” At the time of the report, natural gas was being used as a fuel in the Union Iron Mills and the Black Diamond Steel Works. It was only a short time until natural gas became cheaper than coal and for the time being supplanted the latter as a fuel. SO ME ENGINEERING PHASES 13 ENGINEERS’ SOCIETY. However, before 1885 Pittsburgh became alive at least to the question of coal economy. In 1881, William Metcalf, an eminent engineer and mill owner, read a paper before the Engineers’ Society of Western Pennsylvania on “Some Waste of Heat.” In the introduction to his paper he declared that he “proposed to show by figures obtained from actual working data, how much money is annually thrown away in Allegheny County by throwing coal into our furnaces in the shape of coal, to be sent, wasted, out at the tops of the stacks in the shape of dirty, useless smoke, and red and far more expensive flames.” He esti- mated the cost to be $1,063,000. In 1884 it is estimated that Pittsburgh was using an- nually 3,000,000 tons of bituminous coal. With the in- troduction of natural gas this fell off to less than 1,000,000 tons. The regime of natural gas was brief. About 1890 the coal consumption again began to move upward and by 1895 King Coal had resumed his throne. LESSON OF A CLEAN CITY. But Pittsburgh knew what a clean city was like. It had actually been experienced. It was only natural then that the people protested when the smoke began to in- crease. The question was taken up by the Ladies’ Health Association of Allegheny County. The prime mover in this organization was the late Miss Kate C. McKnight, who was very active in civic work. This association merged with the Civic Club of Allegheny County when it was organized in 1895. A committee from the Health Association was present at the meeting of the Engineers’ Society in February of 1892 when William Metcalf, re- ferred to above, read a paper which was a partial defense of smoke. In the discussion that followed this paper one of the speakers said: “We are going back to smoke. We had four or five years of wonderful cleanliness in Pittsburgh, and we have all had a taste of knowing what it is to be clean.” 14 THE SMOKE INVESTIGATION At the March meeting of the Engineers' Society, the Ladies’ Health Association presented its side of the story. The result was that the engineers appointed a Committee on Smoke Prevention, which reported in the latter part of the same year. ACTION BY THE ENGINEERS’ SOCIETY. In this report the committee recommended: (1) That the Women’s Health Protective Association or some sim- ilar organization, continue its efforts toward smoke pre- vention by educating the community in its principles and advocating the use of smokeless fuel in dwellings and the best stokers or other devices in manufactories and steam plants. (2) That the City Council should pass an ordi- nance for the abatement of the Smoke Nuisance, insist- ing on the absence of dense smoke from stationary, steam- boat and locomotive boilers except when fires are started, but recognizing the necessity of puddling and other fur- naces which require a small excess of carbon for proper working. (3) That one of the duties of the Building In- spector or of persons appointed for the purpose, should be to see that the newly erected buildings have properly designed flues and ample room for furnaces with particu- lar reference to economical combustion and the non-emis- sion of smoke. It is interesting to note that in this first report on the smoke nuisance, the importance of having all plans and specifications for the installation of boilers and fur- naces come under the supervision of a properly qualified inspector, was recognized and emphasized. It is also in- teresting to note that scarcely a year has passed since the founding of the Engineers’ Society, a committee from which formulated the above mentioned report, but that a paper dealing with some phase of the smoke problem has been read before it. Practically every phase of the problem as it affects both the producer of smoke and the business and general public who suffer from its effect, has been presented before the Engineers’ Society. SOME ENGINEERING PHASES 15 FIRST GENERAL ORDINANCE. There is little doubt that as a reult of the agita- tion on the part of the Ladies’ Health Association, and because the city was forced to give up the use of gas in the pumping station, in 1891, on account of the increased price, the City Councils passed the first general ordinance. This ordinance of March, 1892, provided that after September 1, 1892, it should be unlawful for any chimney or Smoke stack used in connection with a stationary boiler to allow, suffer or permit smoke from bituminous coal to be emitted or escape therefrom, within a certain district. This district was bounded by Miltenberger, Din- widdie, Devilliers and Thirty-third streets on the west and the city line on the east. Its northern and southern boundaries were irregular, being arranged according to a newspaper, “so as not to affect a number of iron works, steel works, oil refineries and other industries for which successful smoke consuming devices have not yet been pro- vided.” It will be observed that this ordinance excepted the business section of the city, bounded by Grant street, the Tenth street bridge and the two rivers. The ordi- nance was chiefly notable for its exceptions. The power of enforcing this ordinance was placed in the hands of the Department of Public Works. EFFORTS AT THE PUMPING STATION. Edward M. Bigelow, who was then Director of the Department of Public Works, assigned the duty of en- forcing the ordinance to the Superintendent of the Bureau of Water Supply. The city decided very properly to clean up its own stacks, which were sending forth black smoke, and at the same time to give a demonstration of what might be done in the way of burning bituminous coal for steam making purposes without emitting black smoke. The story of the attempt to make the Brilliant Pump- ing Station smokeless is a most instructive one. No doubt it explains why plants other than municipal ones are still making black smoke. At first the work at the pumping 16 THE SMOKE INVESTIGATION station was pushed with vigor. The work of installing stokers was started in 1893. In 1894 the Superintendent said in his report: “None of the smokeless devices are smokeless except under favorable conditions.” Mr. Bige- low, the Director of the Department of Public Works, was more optimistic, for in his report for that year he said: “I may say that we have solved the problem of smoke prevention at the pumping stations.” In 1908, the Super- intendent reported: “We have continued our efforts to prevent an unnecessary amount of smoke at this station.” It is interesting to note in connection with the review of the efforts put forth by the city at the Brilliant Pump- ing Station that in his 1913 message to Council, Mayor Magee said, “Your attention is called again to the fact that one of the worst offenders against the smoke ordinance is the City of Pittsburgh at the Northside light plant and the Brilliant Pumping Station.” In May of 1895 a second smoke ordinance was passed. This ordinance provided in Section 1, that the emission of more than 20 per cent. black or dark gray smoke from any stack should be considered a public nuisance. Sec- tion III provided a fine for the emission of smoke for over three minutes. The decision of the Superior Court in the case of Pittsburgh vs. W. H. Keech Company virtually made this ordinance inoperative. THE WORK OF THE CHAMBER OF COMMERCE. In January, 1899, the President of the Chamber of Commerce, appointed a Committee on Smoke Abatement. This appointment was, no doubt, brought about in a measure by the speech of Andrew Carnegie at the annual banquet of the Chamber in November of 1898. In speak- ing of the Smoke Nuisance he said: “We all know that many of our citizens are tempted just at that period of their lives when they would be of most use to our city, in furthering the things of a higher order, to leave Pitts- burgh to reside under skies less clouded than ours. The man who abolishes the Smoke Nuisance in Pittsburgh is SOME ENGINEERING PHASES 17 foremost of us all; to him be assigned first place, and to him let our deepest gratitude go forth.” After the appointment of its committee the Chamber of Commerce requested that a committee be appointed from the Civic Club of Allegheny County and from the Engineers’ Society to co-operate with it. While the Civic Club promptly accepted the invitation, the Engineers' So- ciety, for reasons of its own, withheld its co-operation. This combined committee reported in December of 1899. Among other things in this report, it said: “If your committee believed that it was not practi- cable to, at least, greatly diminish the smoke nuisance throughout the commercial and residence districts of the city, it would frankly say so and ask for summary dis- missal. * * * The efforts of our city government to- ward the abatement of the Smoke Nuisance have so far not met with notable success; a fact chiefly due to the absence of laws for the enforcement of the city ordinance for this purpose.” The committee suggested asking the Legislature for power to compel offenders to comply with the ordinance. CREATING A SMOKE INSPECTOR. As a result of the work of this committee an ordi. nance was passed in December, 1906. This ordinance held the emission of dense black or dense gray smoke for more than eight minutes in any one hour to be a nuisance and prescribed the penalties for the violation thereof. How- ever, it made no provision for the enforcement of this ordinance by any particular bureau. In January of 1907, Council passed an ordinance introduced by this committee creating the office of Smoke Inspector. At the request of Mayor Guthrie and in recognition of the efforts of this committee—this being prior to the enactment by the Legislature of the Civil Service Law—a civil service examination was held under the supervision of the committee to secure a man fitted to take the posi- 1 Year Book and Directory, Chamber of Commerce, 1900. I8 THE SMOKE INVESTIGATION tion of Smoke Inspector. William H. Rea was selected and active work was begun under the new ordinance in June, 1907. The administration of Mr. Rea was a very efficient one, resulting in a material reduction of the smoke nuisance in the city. THROWN OUT OF COURT. In 1909 Mr. Rea resigned and Mr. J. M. Searle was appointed by Mayor Magee to succeed him. On March 3, 1911, the ordinance was declared void in the case of the Commonwealth of Pennsylvania vs. Standard Ice Com- pany. The grounds of this decision were, first, that the Legislature of Pennsylvania had likely not given the city any sufficient authority to pass ordinances upon the sub- ject of the emission of smoke and without such authority the city could not act—this, however, was not definitely ruled—and, second, that the ordinances were unreason- able. On June 6, 1911, the Legislature passed an act au- thorizing cities of the second class to regulate the emis- sion of smoke, and in September, 1911, a new ordinance— the present one with one modification, that of the excep- tion of mill heating furnaces and puddling furnaces, was passed. On September 22, 1911, Mr. Searle resumed his work as Chief Smoke Inspector. SMOKE INVESTIGATION OF MELLON INSTITUTE. About the same time that Mr. Searle again took up his work as chief smoke inspector in 1911, a Pittsburgh business man provided Robert Kennedy Duncan, the Di- rector of the Mellon Institute, with a fund for an investi- gation of the Smoke Problem. The present report is one of the publications issued by that Investigation. SOME ENGINEERING PHASES 19 Part II. Evidences of the Smoke Nuisance. Neither to those who live in, nor to those who even visit Pittsburgh or any other industrial center, which burns a large quantity of bituminous coal, is it necessary to present evidences of the smoke nuisance. The “smoke readings” given under the Survey of Plants gives some idea of general conditions. One need not be a smoke in- spector to know that Pittsburgh has a smoke nuisance. The interesting question is as to the extent of the smoke nuisance. The two sets of pictures given in this report will give an idea of what the actual conditions are and what they could be. The Smoke Investigation also made a study to determine the amount of solid matter in the atmosphere. This study gives a clue to the nature and extent of the nuisance in Pittsburgh. Everyone is more or less familiar with the popular way in which explanation is given to account for the carrying of clouds of dust, ashes and smoke by the action of winds. During the existence of a calm or a very light breeze the dust, soot and other particles that issue from the chimneys or stacks rise to elevations which depend upon the draft artificially or otherwise produced. Many of these particles are, as a rule, quite light and because of this fact they settle very slowly to the ground or to their final resting places. While these particles are in the air they may float away to considerable distances, de- pending upon the circulation currents established in the atmosphere by their own upward motion, combined with the movement of large masses of the air due to meteoro- logical changes. The heavier particles in these clouds necessarily fall to the ground much sooner than the lighter ones. All along the pathway of such a floating cloud, dust or other 20 THE SMOKE INVESTIGATION particles may be detected in greater or less abundance. There is reason to believe that the finer and lighter par- ticles travel for many miles, especially when wind condi- tions are favorable. Similar phenomena are observable on an immense scale in the case of Volcanic dust. The atmospheric pollution may be due to the simul- taneous existence of gases and fumes with the solid par- ticles. The former are more or less invisible and are like the latter thinned out as they travel far away from their origin, until they finally disappear from view. STUDY OF PITTSBURGH’S SOOT-FALL. To determine the amount of solid matter in the at- mosphere of Pittsburgh, its distribution and composition, twelve stations were selected in various parts of the city. The stations at which measurements were made, and their location, which may also be found by reference to the soot-fall map, Figure 2, are as follows: SOOT COLLECTING STATIONS. STATION. LOCATION. DISTRICT, 1. Cargo School, Boggs Avenue, Mt. Washington. 2. Ohio Valley Bank, Preble Street, Woods Run. 3. Allegheny High School, Sherman Avenue, North Side. 4. Oliver Building, Smithfield & Sixth Ave., Downtown Dist. 5. Irene Kaufmann Settlement, 1835 Center Avenue, Hill District. 6. State Hall— University of Pgh., O’Hara Street, Oakland. 7. Peebles School, Tecumseh Street, Hazelwood. 8. Ormsby Park, S. 22nd Street. South Side. 9. Colfax School, Phillips Ave. & Beechwood Blvd., Squirrel Hill. 10. Brushton School, Brushton Avenue, Brushton, Pa. 11. Arsenal Park, - Butler Street, Lawrenceville. 12, Margaretta School, Margaretta Street, East Liberty. Table I gives the weight of the soot-fall in grams at each station for each month. Below the table is given the calculated weight of the soot-fall at each station in tons per square mile for the entire year. º: 4912 - 1213 **w, * * As amas. 3 ºr Faua - Tess ºf a $4 a as a stres * Qºwrcs & ºv Pants or Prºrs suae - Gºwreyss fºr Teºs SOOT FALL MAF *** *********** * * **A* -ses. •ere sºar º- - - *—it –-º Figure 2—Soot-fall map of Pittsburgh. TABLE I—PITTSBURGH’S SOOT-FALL SAMPLES IN GRAMS PER MONTH, APRIL 1912 TO APRIL 1913. STATION NUMBERS. Month. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. April, 12 .3806 .5106 .2722 .5308 .5501 .4186 .1184 .2596 .1821 .1341 .2599 .1603 May .1081 .4146 .1142 .5198 .5882 .0873 .1384 .1915 .1332 .1192 .1676 .2778 June .2552 .5714 .2752 .4872 .4000 .3604 .2142 .3306 .1863 .1374 .2026 .1315 July .1450 .6924 .2570 .3900 .5520 .2282 .2030 .3364 .1732 .1564 .2678 .1938 August .1104 .5154 .1460 .2608 .3570 .1828 .2022 .2266 .1732 .1142 .2024 .1210 September .1114 .5038 .1910 .2022 .3278 .1830 .1832 .2040 .1826 .1282 .2136 .1426 October .1380 .5610 .2182 .3124 .4622 .2488* .2072 .3254 .1664 .1636 .294.2 .1554 November .0526 .7700 .1290 .2188 .3860 .2166 .2076 .1734 .1586 .1836 .2088 .1742 December .1380 .7522 .3428 .4896 .3788 .3988 .2860 .1484 .4282 .3702 .4276 .2518 January, '13 .1278 .5232 .2660 .6398 .2828 .2742 .3092 .2456 .2094+ .3154 .3206 .1948 February .1034 .6200 .2642 .4574 .3746 .2042 .0914 .1462 .1278 .1420 .2894 .1242 March .1550 .5438 .1956 .5876 .3342 .1972 .3236 .3346 .1750 .2462 .1924 .1946 Total 1.8255 6.9784 2.6814 5.0964 4.9937 3.0001 2.4846 2.9223 2.2960 2.2075 3.0469 2.1220 Tons per sq. mi. 595 1,950 670 1,660 1,630 978 812 922 748 721 995 693 *The October jar from Station No. 6 was broken and the January sample from Station No. 9 froze and the jar was broken. The weights of the soot-fall were calculated by taking, in the case of the Octo- ber sample of No. 6, the average per cent. of the October precipitate of the total of 12 months for the 10 full year samples. From this and the weight of No. 6 for 11 months the October precipitate was calculated. No. 9 for January was calculated in the same way. This gives a better weight than a simple average would. - § TABLE II—PER CENT. ANALYSIS OF YEAR’S SAMPLE OF EACH STATION, STATION NUMBERS. 1. Tar 2.19 Ash 75.84 Fixed carbon 21.97 Fe. O3 in ash 24.3 Fe:O3 in deposit 32.08 2. 0.8 62.6 36.58 21.1 33.73 2 3. 1.56 68.30 30.14 40.1 58.78 4. 1.12 73.77 25.11 22.9 30.98 5. 1.26 76.82 21.92 33.6 43.66 6. 0.36 66.68 32.96 31.6 47.44 7. 1.00 61.94 37.06 23.8 38.44 8. 0.74 68.20 31.06 33.38 22.8 9. 0.62 71.16 28.22 35.42 25.2 10. 0.42 61.42 38.16 24.05 14.8 11. 0.76 59.96 39.28 36.52 21.9 12. 1.04 70.14 28.82 31.47 22.1 § 24 THE SMOKE INVESTIGATION The soot collected at the different stations was ana- lyzed according to standard methods. Table II shows the percentage of tar, ash, fixed carbon, iron oxide in ash and iron oxide in the entire deposit, of sample of soot-fall at each station. The table given below shows the calculated amount in tons per square mile of tar, fixed carbon, ash and iron oxide that fell at the different stations during the stated year. TABLE III—CALCULATED WEIGHT OF CHEMICAL COMPOSI- TION IN TONS PER SQUARE MILE PER YEAR. 1 2 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. Tar 13 16 10 19 21 4 8 7 5 3 8 7 Fixed carbon 131 713 202 417 357 322 300 286 2.11 274 391 200 Ash 306 809 189 844 704 343 309 419 344 336 378 333 Fe2O3 145 412 269 380 548 309 195 210 188 108 218 153 3 It is a matter of regret that similar soot-fall studies have not been made for other cities of the United States so that a comparison could be made of the amount of smoke in them. A number of studies have been made in cities of Great Britain. It was found, for instance, that in the city of Leeds the annual soot-fall varied from 26 tons to 539 tons per square mile. In 1910 observations were carried on in London and it was ascertained that the annual soot-fall in the center of London was 426 tons, while the average for the whole city was 248 tons per square mile. Observations made in Glasgow during the winter of 1910-1911 showed an annual SOOt-fall Of 820 tons per square mile in the center of the city. When these figures are compared with Pittsburgh's average annual soot-fall of 1,031 tons per square mile, it would appear that either the methods of making calculations differ widely, or what appears to be the more plausible ex- planation—that Pittsburgh is a very smoky city. SOME ENGINEERING PHASES 25 Part III. The Contributing Causes of the Smoke Nuisance. While the underlying cause of the smoke nuisance is the incomplete combustion of bituminous coal, there are, as was stated in the introduction, what may be termed contributing causes of the smoke nuisance. In the first place, the coal which is found in the District is very plenti- ful, cheap and rich in volatile matter; secondly, the in- dustries of the District are those which consume large Quantities of coal. The District uses more bituminous coal than any other district of like size in the world. In the third place, the many hills and valleys, and the frequent fogs hold the smoke that is made long after it would have been carried away in another locality having a more regu- lar topography. THE COAL FIELD. Pittsburgh, as is well known, is the center of the bituminous coal field of Pennsylvania. This coal field comprises an area of about 14,200 square miles; and it contributes 95 per cent. of the total bituminous output of the State, and one-third of the total bituminous output of the United States. The amount of coal originally in the bituminous field of Pennsylvania is placed at 112,574,000,000 short tons 1 . The total production to the close of 1911 amounted to 2,396,491,260 short tons. It is said that even at the present rate of exhaustion, the coal supply will still last about 475 years. It may be seen at once that Pittsburgh will be forced to battle with the smoke nuisance for years to come. 1 United States Geological Survey—“The Production of Coal in 1912,” by Edward W. Parker. 26 THE SM OKE INVESTIGATION In 1912, 161,865,488 short tons of coal were mined in the District. The value of this coal was $1.05 a ton at the mine. The Pittsburgh coal, which is found in this field, is the most famous coal bed in America. The bed gives 9 feet of available coal over large areas, and seldom runs under 4 feet. ºr THE COMPOSITION OF PITTSBURGH COAL. Coal consists of moisture, ash, fixed carbon and vola- tile matter, the relative amounts of each varying consider- ably according to the locality or bed from which the coal is mined. The moisture in coal is obtained by heating a finely powdered sample in a crucible for one hour at 104° to 107°C. The loss in weight represents the moisture. The amount of moisture varies from as low as 0.76 per cent. in the best grade of semi-bituminous coal to as high as 40 per cent. in the case of lignites. For coal from the Pittsburgh bed, the moisture contents in mine samples varies from below 1 per cent. to over 4 per cent. Ash, which is ordinarily the mineral residue after the coal is burned, varies from as low as 2 per cent. in some West Virginia coals, to as high as 25 per cent. in dirty slack. Mine samples of Pittsburgh coal shows that the ash in it varies from 4.5 per cent. to 12.9 per cent. Fixed carbon, which represents the difference obtained by subtracting the percentage of moisture, volatile matter and ash from 100 per cent., varies from as high as 80.6 per cent, in the better grades of semi-bituminous coal to as low as 33 per cent. in the poorer grades of bituminous coal. For Pittsburgh coal, fixed carbon varies from as low as 44 per cent. to as high as 59 per cent. To obtain the amount of volatile matter in coal, one gram of a finely ground sample, placed in a covered plat- inum crucible is held Over the full Bunsen burner for 7 minutes. The loss in weight represents moisture plus volatile matter. When the value of the moisture is sub- tracted from this result the remainder represents the SOME ENGINEERING PHASES 27 amount of volatile matter. In the best grades of semi- bituminous coal it will go as low as 12.3 per cent., while in some good grades it will run as high as 41.4 per cent. ; and in the poorer grades, from 31.2 per cent. to 37.4 per cent. The volatile matter in Pittsburgh coal varies from 30.9 per cent. to 41.4 per cent. of the fuel 4. As a rule, the amount of volatile matter may be considered a good indication of the smoke producing nature of the coal. However, volatile matter itself, varies in composition from that containing gases and compounds, which are not difficult of consumption in an ordinary furnace with- out the production of smoke, to that containing gases high in hydro-carbons in tar, which can only be burned with- out the production of smoke, in carefully constructed and operated furnaces. Pittsburgh coal, because of its vola- tile composition, is more smoky than other coals which have the same volatile content. In order to understand why it is so difficult to burn the Pittsburgh coal without smoke it may not be out of place to discuss at this point the general process of com- bustion. The process of combustion is a simple one, being a chemical union of the combustible material of a fuel with the oxygen of the air resulting in the development of heat. In practice, however, many difficulties are en- countered which tend to complicate the process, and it is in overcoming these that care is required in the opera- tion and construction of furnaces. The number and nature of the difficulties vary considerably with the fineness of the fuels, the type of furnaces used, the amount and com- position of the impurities in the fuel, and the variable demands for power. There are three separate and distinct stages involved in the combustion of coal. First, there is absorption of heat. When fresh fuel is fed to the furnace, its tempera- ture must be raised to the kindling point in order that chemical combustion may begin, Second, in order, is the 1 United States Geological Survey Professional Paper No. 48 and United States Geological Survey Bulletin No. 290. 28 THE SMOKE INVESTIGATION distillation and combustion of the volatile portion of the fuel; and third, the combustion of the remaining or car- bonaceous portions of the fuel. After the hydrocarbons have been driven off and more or less consumed, the re- maining portion of the solid matter is composed mainly of carbon and ash. It is comparatively simple to secure complete combustion at this stage, so that the solution of the smoke problem deals largely with the combustion of the products evolved in the second stage of combustion. Therefore, the smokeless combustion of bituminous coal depends upon the construction and operation of furnaces in such a manner that the volatile products evolved in the second stage of combustion, are completely consumed before they strike any cooling surfaces which will reduce their temperature below the kindling point. Briefly stated the principles involved to secure these results are: (a) Air in sufficient quantities for complete com- bustion must be admitted at the proper time. (b) The air must be thoroughly mixed with the gaseous portion of the fuel. (c) The temperature of the gases must be main- tained above their kindling point until the chemical proc- ess known as combustion is complete. PITTSBURGH’S INDUSTRIES. The nature of the industries in which any city is engaged depends largely upon the natural advantages of the district in which it is located. The fact that iron and coal were so accessible determined the lines of indus- trial development in Pittsburgh. Of the two, coal has been demonstrated to be the more valuable. As some One has put it, “Coal is the rock upon which Pittsburgh is built.” While the first industries of the city did not depend upon natural advantages, it was not long before enter- prising Pittsburghers began to take coal from the hills of the District to use in furnishing power for their man- ufactories. The accessibility of iron ore, together with SOME ENGINEERING PHASES 29 this coal determined the industrial development of the District. As early as 1792, a blast furnace was built in Shady Side. While pig iron was not produced in the city until about 1850, in twenty years' time the Pitts- burgh District had surpassed all other iron producing dis- tricts in the country. When steel came to supersede pud- dling iron, Pittsburgh naturally became the center of the steel industry. In 1850, when the city had a population of 46,606 there were thirteen rolling mills and thirty large foun- dries, which, together with cotton and glass factories, con- sumed about 12,000,000 bushels of coal. It was about this time that the city received the title “The Iron City” and shortly afterwards “The Smoky City.” The census report for 1910 shows that the industries which use ore and metal as the principal materials, and accordingly great quantities of coal, as blast furnaces, steel works, rolling mills, foundries and machine shops, formed more than 50 per cent. of the total value of all manufactured products for the city proper. The city was given seventh rank in the value of manufactured prod- ucts in the census of 1910. The Statistics for the Pitts- burgh Industrial District showed that it ranked fourth. In 1909, the Pittsburgh District produced 11 per cent. of the world’s output of pig iron; 30 per cent. of the steel man- ufactured in the country; 50 per cent. of the country’s steel cars; and 66 per cent. of the country’s glass. In the city in 1909 there were 307,666 primary horsepower em- ployed in manufacturing alone, of this, 227,231 or 73.9 per cent. was assigned to the manufactory of electrical machinery and apparatus, foundry and machine shop prod- ucts, iron and steel blast furnaces, iron and steel works, and rolling mills. Of the total capital invested in man- ufactories, 95.5 per cent. was invested in these industries and they account for 60.9 per cent. of the total expendi- fire for fuel and rent of power. In the District, the above mentioned industries, required 80.7 per cent. of the total primary horsepower utilized in manufactory. 30 THE SMOKE INVESTIGATION THE COAL CONSUMPTION OF THE DISTRICT. Coal is the general source of power for all manu- facturing purposes in the Pittsburgh District and is ap- plied either directly or indirectly to metallurgical proc- esses as a source of heat in carrying out the various opera- tions. It is almost universally used for heating where heating is done on a large scale, as in office buildings, hotels, store buildings and central heating plants. In some instances it is used for heating dwellings, but is not used extensively for other domestic purposes. The part consumed for all domestic purposes is negligible when compared to the amount, used in power generation and for metallurgical purposes. While coal was mined in Pittsburgh as early as 1760 it was not used for domestic purposes until 1780, for fire- wood was plentiful, cheaper and cleaner than coal. As was stated in “The History of the Smoke Nuisance,” the consumption of coal had reached 3,000,000 tons in 1884 when natural gas was discovered. This consumption fell to about 1,000,000 tons until 1890 when it began to in- crease again. The only figures that are available on the coal con- sumption of the city of Pittsburgh are those furnished by Mr. J. M. Searle, the Chief Smoke Inspector of Pitts- burgh. Mr. Searle's figures show that the coal consump- tion of the city for 1912 to be 5,606,416 tons. The con- sumption of coal in the Pittsburgh District for 1912 amounted to 17,721,783 tons. ' This makes the Dis- trict the largest consumer of bituminous coal in the world. The District is not only the largest consumer of bitumin- ous coal, but when to the coal consumption is added some 5,000,000 tons of coke and the gas consumption for 1912 equivalent to over 3,000,000 tons of bituminous coal, the District becomes the greater user of fuel in the world. 1 United States Geological Survey—“The Production of Coal in 1912,” By Edward W. Parker. i Ş s'sſ | i i i SOME ENGINEERING PHASES 33 TOPOGRAPHY OF THE PITTSBURGH DISTRICT. Pittsburgh is located on the point of land where the Allegheny and Monongahela Rivers join to form the Ohio, as is shown in Figure 1. The city of Pittsburgh includes within its limits 41.4 square miles, and, what is known as the Pittsburgh District, comprises an area of 634.2 square miles. The city and district are situated among the foot- hills of the Allegheny Mountains, and the country is, in general, rough and irregular in its topography, as may be seen from the “Relief Map,” Figure 3. This map shows that the hills vary greatly in height and steepness. In a number of instances, within the city, the hills are so steep that they have to be ascended by inclines. This is par- ticularly true of the South Side where the high hills ap- proach the Ohio and Monongahela Rivers so closely as to allow scarcely room for the construction of public high- ways and railroad beds. Figures 4, 5, 6, 7, 8 and 9 show photographs taken on the South Side, not far from the top of the hillside, opposite the “Point” of the city. Photographs 4, 6 and 8 were taken on the Fourth of July when very few mills and factories were in operation. The day was excep- tionally clear and the sky was, at times, almost cloudless. They give an idea of the condition that could prevail in Pittsburgh even with the mills and factories in opera- tion, provided the proper care was taken in burning coal. Photographs 5, 7 and 9 were taken from the same point on October 8th, between the hours of 12 M. and 3 P. M. The wind was coming from the Northwest and was travel- ing at the rate of twenty miles an hour. The day was not a foggy one, but, as can be seen from the pictures, was very smoky. Figure 4 is a view down the Ohio River and shows Brunots Island in the center of the background. The low sloping land upon which the old city of Allegheny is located is seen on the right and the steep hills on the South Side, on the foreground and left. Figure 6 com- 34 THE SMOKE INVESTIGATION bined with Figure 4 gives almost a panoramic view of the North Side. Figure 8 shows a view of the “Point” at the junction of the Allegheny and Monongahela Rivers with the Ohio. Again the steep sides of the hills on the South Side are shown. In this picture the waters of the Monongahela are very muddy due to the recent rains along its course. The photographs represented by Figures 10, 12 and 14 were taken from the top of the Oliver Buliding on the same day as Figures 4, 6 and 8. Photographs shown in Figures 11, 13 and 15 were taken on the same day as Figures 5, 7 and 9, and show the smoky condition of the city. Figures 10 and 12 show the Allegheny River as far up as Herr's Island. In Figure 12, the Pennsylvania Railroad Station is represented just above the center of the picture and just back of it is seen one of the inclines. Figure 14 shows a view of the city looking southeast from the Oliver Building. The picture takes in what is known as the “Hill District.” Part of the work in the “Hump Cut” in seen in the foreground. Figures 4 to 14 taken together with the “Relief Map,” Figure 3, show, in general, the roughness and irregularity of the land upon which the city is located. Figure 16 represents the Pittsburgh Flood Commis- sion Map from its Survey, July to October, 1909, and gives the location of the steel mills and factories along both banks of the rivers of this District. It shows how the city, especially the business district, is closed in by mills and factories. THE WIND DIRECTION AND THE SMOKE NUISANCE. The effect of wind direction upon the prevalence of smoke in different parts of the city may be traced in the following manner: (For prevailing winds see Appendix 11). (1) North Winds: The smoke from the north side of the Allegheny River combines with the greater volume from the mills and factories on the South Side; and for a Contrast Views of Pittsburgh. Figure 4–View down the Ohio River when the city was free from smoke. Photo by H. C. Anderson º: * - _ l f - - º 38 uos uºpuv （O ‘H ºd oņoti，I · × ep x>ſours e tio 9 ºunºſ） uſ se waſ， ºu es-1 ºu nº 1:1 3:) Figure 8–View of the “Downtown Section” when the city was free from smoke. Photo by H. C. Anderson t * * * { 1. _ * 3 41 § Figure 10–View up the Allegheny River when the city was free from smoke. Photo by H. C. Anderson u osua puv （O ‘IH Kd on ottaeſ · xep x>ſous e uo 01 ».īnāſ） uſ se wº! A ºures—IIøanºſ. H │ │ │| （）|× |- L.- Baewae 13 º º - - -- - - º – Hºnº - - º º º - Figure 12–View in direction of Pennsylvania Station when the city was free from smoke. Photo by H. C. Anderson - - I -- - u osua puv （O ‘H & q oqotſaſ • Kep ,，ſouus e uo z I º anºſ, I uſ se wº! A ºu BS-81øanºſ， |- |- ， · ）); · （ ） - - . . . |- 45 uos uºpuv （O ‘H  q oqotIaI. 'ºx{ouus uuouſ ººuſ sew qų uøųw \!!0 ºu q ssoluotº ,stº wºļA – † 1 ºunºſ）. （~\~ Trſë， ！ ！ ！ 46 ±1） • Kep ，，ſouus e uo +1 ºunº 1，1 uſ se wºțA 9uues-gI a.in u osua puv （O ‘H KQ on ott. IAſep  47 SOME ENGINEERING PHASES 49 distance of almost four miles east of the “Point” the busi- ness, as well as the park and residential sections of the city, are subject to its evil effects. A glance at Figures 9 and 13 will show that the busi- ness district as far east as the Pennsylvania Railroad Station receives this smoke at low levels, especially when the wind is high. At such times apart from the additional clouding effect of fogs, the streets of the lower parts of the city afford avenues for the passage of the smoke south- ward and due to the smoke eddies which form, there is no possible means of preventing the smoke, ashes, etc., from penetrating the stores, office buildings, hotels, the- aters, etc. When the North Wind has a low velocity approach- ing a calm, there is a greater tendency for the smoke cloud from these same sources to rise to higher elevations, espe- cially the lighter portions of it across the city. The heavier constituents of this smoke cloud, however, such as ashes and ore dust, settle to the ground or on their final rest- ing places within a short distance from the localities where they were produced. Between these two extremes of wind velocities, the city’s life and activities must certainly experience the ill effect of the impurities in the air and simultaneously there are losses along many economic lines. During the preva- lence of the North Winds, that portion of the city east of the Pennsylvania Railroad Station has a deflecting wall in the high sloping hill sides on the south bank of the Allegheny River. The general effect is that the smoke clouds are de- flected on these more or less sloping hill sides, and are driven into higher elevations, above the buildings and thus they are carried in sheets high over our heads across the Oakland, Schenley Park and Squirrel Hill Sections of the city. (2) Northwest Winds: These bring the smoke from the mills and factories along the Ohio River (See Figure 16) and give the business section of the city, perhaps its most complete deluge of smoke, ashes, etc. Even without - : SOME ENGINEERING PHASES 51 the existence of fogs, it is quite commonly the case that the stores, office and other buildings have to be illumin- ated throughout the day. What has been said as to the penetration of the smoke cloud under North Winds, is con- siderably magnified under the Northwest Winds. It is fikewise true that the residential and park districts re- ceive their share of the smoke from the mills along the Ohio River in addition to that already outlined under the NOrth Winds. (3) West Winds: During the existence of Westerly Winds, the business section of the city is as free from smoke as it can possibly be, under existing conditions, the only sources of smoke being a number of small mills and factories on the South Side, and directly west of the “Point,” also the few mills and factories scattered throughout this part of the city itself. It is only necessary to carefully examine the Flood Commission Map, Figure 16, to realize the truth of these statements. There is a narrow section of the city which is in the direct path of the West Winds which have already swept over the business portion of the city. This part of the city is located on the high and sloping background, as seen in Figures 8, 12 and 14, and due to the high hill sides to the east and right of the Pennsylvania Railroad Station, and on the south side of the Allegheny River, the smoke is somewhat deflected, and tends to be driven up the Allegheny Valley, thence to spread over the resi- dential and Highland Park sections of the District. At the same time the smoke from the mills and fac- tories along the Monongahela River is carried up the river valley for a short distance (on account of the high hills on the South Side), and then spreads eastward over the residential and park districts. (4) Southwest Winds: When the Southwest Winds are blowing, the smoke from the mills and factories at McKees Rocks and also those along the north bank of the Ohio River is driven across the North Side, or the old city of Allegheny, and thence spreads over Reserve, Shaler and other townships in its course. 52 THE SM OKE INVESTIGATION From the mills along the Allegheny River, up as far as Sharpsburg, the smoke generally follows the course of the river and does not spread appreciably for a distance of nearly five or six miles from the “Point.” At the same time the business portion of the city suffers very little more than it does due to West Winds. The smoke clouds, due to the industries along the Monongahela River, are carried by these winds up and over the sloping hill sides on its north bank as seen in Figures 9 and 15, and spreads over the park and residen- tial portions of the districts shown in Figure 15. For winds in any other directions than those dis- cussed, a reference to the pictures will enable any one to determine with a fair degree of reliability the distribu- tion of smoke in the city. - From the discussion thus far presented, and by the aid of maps and pictures in considering the topography of the Pittsburgh District, it will be realized that there is truth in the statement that “the non-production of smoke is the Only solution of Pittsburgh’s smoke problem.” SOME ENGINEERING PHASES 53 Part IV. The Sources of Smoke in the City of Pittsburgh and the Pittsburgh District. The smoke in the city of Pittsburgh comes from many sources, both within the city limits and from the out- lying districts. The smoke from the surrounding terri- tory is mainly from the large manufacturing plants which border on the city. The smoke within the city limits may be traced (1) to the business section, (2) to the manufac- turing plants, (3) to special furnaces, (4) to the railroads, (5) to steamboats, (6) to the residential portion, and (7) to miscellaneous services. The condition under which smoke is made at each source and remedies will be dis- cussed under special headings. THE BUSINESS SECTION OF THE CITY. There is probably no portion of the city in which smoke causes more inconveniences and loss, besides affect- ing directly so many people, as does that made or dis- charged within the business section or its immediate vicinity. The smoke made in the business portion itself comes mainly from some of the large office buildings equipped with their own plants for furnishing power and heat, from various stores similarly equipped, and from buildings furnishing heat alone. A number of large office buildings have in operation such heating and power in- Stallations that only little smoke can be observed issuing from their stacks. Such instances are evidence of what can be done, in practically all cases, when application is made of well known devices, the purpose of which is to avoid the production of smoke. There are relatively few Small manufacturing plants in the business portion of the city, but, those that are so located, as well as the 54 THE SMOKE INVESTIGATION small office buildings, are usually persistent smokers, espe- cially during the winter months. The smoke discharged from these smaller buildings, stores and plants is very offensive in that it is usually discharged at low levels and is carried directly into the windows of the buildings, which surround these plants, causing inconveniences and loss to the occupants of the offices in these buildings, and rapid deterioration of furnishings. All pedestrians are subject, likewise to the evils of the smoke and soot from these stacks. The reasons for smoke from these plants is funda- mentally due to lack of care in design and construction of the installations, and in a large number of instances the operation is also very much at fault. The plants, for the most part, are located in the basements or sub-base- ments of these buildings. In some instances the light is very poor and surrounding conditions are not such as to encourage the operators to exert their best efforts. Head room is usually very much restricted, necessitating con- struction of boiler furnaces with small combustion cham- bers, and, the floor space, in many instances, is only large enough to allow the operator to fire his furnaces. Be- cause of these conditions any disposition to install fur- naces with extension fronts, and thereby increase the size of the combustion space, cannot be considered. Tube or heating surfaces are usually exposed directly to the fire, except where the horizontally baffled water tube boiler is used—which usually offers a fire tiled roof over the fur- nace. Boilers are usually set very closely together, allow- ing practically no space for dusting the tubes of vertically baffled water tube boilers, and no provision is made for having access to stokers and furnaces for making re- pairs. e In most cases the stacks are very high, yet the draft is almost universally poor. This is due to the tortious manner in which the breechings are usually installed, in- volving a large number of short sharp turns and bends, each one of which decreases the draft. Because the quarters are cramped there is usually no space provided SOME ENGINEERING PHASES 55 for coal storage, and the operators are dependent on daily deliveries for their supply of fuel, with the result that they are at times required to use fuel which is very much in- ferior in quality. The difficulty of handling poor fuel on this type of installation, without the emission of Smoke, can readily be realized. It is in plants of this type that the need of official approval of all plans for the installations of boilers and furnaces is most forcibly demonstrated. One very fortu. nate feature, however, is disclosed in examination of these plants. In practically all cases, the installations are of such size that they can easily carry loads without being forced. In most of the smaller plants, the installations are hand-fired and are of such construction that the high vola- tile grades of bituminous coal cannot, without very care- ful operation, be burned without the production, at each firing, of large quantities of black smoke. Furthermore, the installation is usually of such size that the owner often feels that considerable care in operation is not warranted, and the coal is fired in large quantities and at irregular intervals by low class labor. The underfeed stoker has lent itself admirably to the remedying of just such conditions as these, in that it burns its fuel with a short flame, therefore, requiring minimum sized combustion chambers to obtain smokeless combus- tion. Especially is this true at low ratings, also, only enough draft is required to carry off the products of com- bustion—as the air required to burn the fuel is supplied under pressure by a fan to the fuel bed. It would be unwise to state that this type of stoker would cure any or all of the existing evils, as each plant has its own stated set of conditions, which need to be thoroughly studied before any remedy can be applied. All plans and specifications for new or alterations in old installations should be prepared by competent ex- perts, so as to enable the operator to keep the smoke emitted by his installation within the ordinance, and ob- tain good efficiencies. All hand-fired installations of size 56 THE SMOKE INVESTIGATION over 300 horsepower should be abolished, stokers installed, and the furnaces redesigned, so that they can be operated efficiently and without the production of smoke. When neither of these remedies suffice, it may become necessary to purchase power and use the plant for heating purposes alone—fired either with gas, some low volatile coal, or coke. Ā considerable portion of the smoke could be elim- inated in the business, as well as residential sections of the city, by the establishment of central heating plants, which would furnish the smaller buildings with heat and power. There are in operation, in the city, sev- eral centralized heating plants which supply the surround- ing buildings with heat and power. These plants, for the most part, operate very successfully from a standpoint of eliminating smoke. MANUFACTURING PLANTS. Under manufacturing plants are comprised all manu- facturing plants not included in the business section, as well as warehouses, breweries, factories, mills, and elec- trical and other power plants furnishing power for vari- ous purposes. The smoke made by these plants consti- tutes the largest portion made in the District. It incon- veniences and affects every portion of the city whether business or residential. These mills, factories and plants are so located that they form practically a chain about the entire city. This fact may be seen from the Flood Commission Map, Figure 16. Some of these plants come within one or two blocks of being included in the area bounded by the business section. A large number of iron and steel mills and other factories are clustered in lower Allegheny, close to the “Point” of the city, and they pro- duce enormous quantities of black smoke and discharge it at low levels. These mills are within a radius of two miles from the business portion of the city, and because the direction of the prevailing winds being northwest this smoke is generally carried directly up the Ohio valley and into the city. Data for the direction of the wind, and SOME ENGINEERING PHASES 57 its velocity, for the years 1911 and 1912, is given under “Prevailing Winds,” Appendix I. The universal fuel used in these plants, because of the low cost and abundant supply, is the high volatile bituminous coal of the District. The general rule seems to be that the nearer these plants are to the center of the city, the smokier is their method of operation. This is the result of the antiquated type of equipment, and methods of installing and operating the same. These plants consist for the most part, of the old style water tube or fire tube boilers operating at moderate pressures, and are in a great many instances hand-fired. The boilers are usually set close to the grates, the heating surface is ex- posed directly to the action of the flames, and all pro- vision for efficient and smokeless operation completely ignored. In some of the smaller plants, the boiler room is placed in one corner of the plant, with space so re- stricted that it is difficult for one to walk about, to say nothing about providing space enough to use the tools usually required when cleaning the fire. The breechings and the connections are usually long and tortuous, and not accessible, or are built into a dividing wall of the building. Breechings have been encountered where three sharp right angle bends have been used in a run of fifteen feet, resulting in a decrease of draft of 0.60 inches of water in this distance. Working conditions for the most part are poor. Dark and dirty boiler rooms are the rule rather than the exception, and in some instances, the fuel, which is dry and dusty, is charged directly from the car to the boiler room floor, and from here it is charged to the fur- nace by hand. In some instances, during the winter months, the boiler rooms are heated by open coal fires discharging smoke and grime directly into the boiler room. This results in making working conditions unpleasant, and decreasing the efficiency of operation. - Considering typical conditions which hold in many plants, mills and factories, as regards poor boiler settings, improperly installed stokers, the class of firemen which is usually to be found operating these plants, and the un- 58 THE SM OKE INVESTIGATION satisfactory working conditions in furnace and boiler rooms, little progress will be made toward smoke elimina- tion until the authorities in control of these plants stand ready to improve the above conditions. From data obtained at a small number of plants, rep- resenting the average operating conditions of the District, there seems to be justification for the statement that the average boiler efficiency, in daily operation, of the boilers of this District is from 15 to 25 per cent. lower than what it should be. The data consisted of analyses of flue gases, observations on temperatures of flue gases and losses to the ash pit. It was also found that by increasing the care in Operation, and properly placing the furnace auxiliaries, which would aid in smoke abate- ment, the fuel consumption might easily be decreased from one-half to three-fourths pound per boiler horsepower de- veloped. It would, therefore, appear that it would not be unreasonable to expect at least a 30 per cent. decrease in the amount of fuel used, provided the proper changes and additions were made. In a majority of the cases in mind, however, a greater return than this would undoubtedly result. It is to be expected that the manufacturer natur- ally hesitates to remedy such conditions as these, unless there is some promise of a remunerative return on the in- Westment. Attempts at smoke abatement in the District have not been attended, in a majority of cases, with the suc- cess that should accompany such efforts, mainly, due to faults in the original design, or maintenance of old and inefficient operating methods. For instance, in one case an attempt was made at smoke abatement by changing baffles and placing firebrick promiscuously about in the combustion chamber, without any regard to its effect on the draft or efficiency of operation of the boilers. Changes were also made in the stoker, by which the air space in the grates was very much restricted, with the result that the coal consumption per square foot of grate surface was very much decreased with an accompanying decrease in the boiler capacity. The result of these efforts showed SOME ENGINEERING PHASES 59. the following conditions: Draft in the furnace 0.10 inches of water, and in the breeching near the stack (two boilers to one stack), 0.90 inches of water; temperature of the gases leaving the boiler 675° Fahrenheit; and the emis- sion of dense clouds of smoke. The refuse from the ash pit at this plant also showed that a liberal percentage of fuel was carried away in the refuse. With a vertically baffled water tube boiler, where the gases are usually required to change their direction of flow three times before entering the breeching, the loss in draft from the breeching to the furnace should not be more than 0.4 inches of water instead of 0.8, as is shown by observation on this setting. The temperature of the escaping gases is abnormally high, 150° higher than it should be if the furnace was operating properly. Consid- ering the fact that the fire, in the above mentioned in- stance, was not in good condition when this reading was taken, that the fuel bed was full of holes, and, that there was a large excess of air, the heat loss up the stack was probably nearer 35 per cent, than 12 per cent. This latter figure represents more nearly the best operating practice. In one instance, of which particular notice was taken, the settings were properly installed, and under careful management the elimination of smoke was accomplished. The methods of firing in this plant are very lax and in- efficient, and no attempt is made to remedy them in con- nection with this new installation. Although this plant, in its present condition, is an improvement on the former one, it smokes badly at times, due to improper handling. Efforts to obtain smoke abatement by such methods, as just mentioned, are very much to be deplored, as the results ac- complished are the direct reverse of what they should be. Two very important factors, both of which aim at efficient and smokeless operation of plants are emphasized in these new installations. They are: First, the importance of proper installation and construction; and second, the need of exercising care and having constant intelligent super- vision of the operations in the boiler room. The large number of recording and other instruments now on the 60 THE SMOKE INVESTIGATION market make possible the obtaining of accurate records of the various elements which effect efficient and smoke- less operation. When special equipment is installed the fact is usually overlooked, however, that considerable care must be exercised in operation, or the results obtained will not be any improvement upon former conditions. It is of the utmost importance, in the remodeling of existing installation and the construction of new ones, that the equipment be so selected, designed and installed, that it will operate at its maximum efficiency without the production of smoke, and with the exercise of minimum care on the part of the attendant. It is unreasonable to expect any high degree of intelligence to be exercised by men of the type usually found in the firerooms of plants of this District. Neither should the fireman be expected to work constantly at the furnace, poking, slicing and firing, especially when a mechanical stoker is supplied, which, in a measure should relieve him of some of these duties. Where the mechanical stoker is installed, the fire- man is called upon to care for a larger number of furnaces than when hand-firing methods are used. This results in a decrease of the amount of attention that each furnace will receive. Any mechanical stoker in which the fuel bed must be continually hooked and poked in order to maintain steam pressure, is not much improvement over hand-firing. In a majority of the plants of the District, firing methods are very lax, firing is poorly done, and intelligent supervision of operating conditions lacking. Especially is this the case with the smaller manufacturing and power plants. In a majority of cases no attempts are made to instruct firemen as to the proper manner of handling fires. New men are usually placed at work without proper in- struction, and they are left to pick up what information they can from their associates in the fireroom. There is but one outcome of such a condition, and that is that in- efficient and laborious methods of handling the furnaces are acquired and clung to most tenaciously. The practice now in vogue in plants where high efficiencies and smoke- SOME ENGINEERING PHASES 61 less Operations are obtained, is to train men to become firemen by permitting them to perform other duties about the fireroom for a reasonable amount of time until they have become familiar with the requirements. These duties consist in assisting the firemen, observing the handling of the furnaces in the proper manner, and the perform- ance of other duties which will acquaint them with the proper methods of furnace operation. Thus by the time they are called upon to serve as firemen they are duly qualified to do so. This plan is much to be preferred over the haphazard method of making any one a fireman who has nothing more in his favor than physical qualifica- tions for the work. Some of the foreign cities, in which great advancement has been made toward smoke elimina- tion, require firemen to be duly qualified and pass an ex- amination before they are given charge of boiler furnaces. These cities maintain instructors and a school where fire- men are given boilers to fire, and are instructed in the proper method of handling stokers and furnaces. Some of the more important factors, a consideration of which will enable the manufacturer to obtain efficient and smokeless operation of his plants, are: Remodeling along proper lines the poorly constructed installations, and replacing old and worn out installations with modern apparatus is highly important; centralized stations of ample size should replace the numerous, small and scat- tered boiler plants; and hand-fired furnaces should be elim- inated in plants of more than 300 horsepower capacity. In addition to these it is highly important that the equip- ment be maintained at its maximum operating efficiency at all times, that careful and scientific supervision of op- erating methods be provided, and, that maximum efficiency from the operating force might be secured, working con- ditions should be of the highest order obtainable under existing circumstances. SPECIAL FURNA CES. The term “Special Furnaces” includes all furnaces for metallurgical processes, such as puddling, heating and re- 62 THE SMO KE INVESTIGATION heating furnaces and soaking pits; furnaces for burning brick, terra cotta and similar purposes and any other class of special furnaces using bituminous coal as a fuel. The most important of the special furnaces of the District, both regarding smoke production and number, are the metallurgical furnaces. (See Figure 17.) The fur- naces of this type which emit Smoke in carrying out the various operations of their processes are: 1. Puddling furnaces used for the manufacture of wrought iron. 2. Heating or reheating furnaces in which the iron or steel is placed to be thoroughly heated after it has once been forged or rolled into rough shapes (when the metal is thoroughly heated in these furnaces it is removed to be rolled into final shapes for use). 3. Hot air furnaces in which either iron or steel is melted for making castings of a better grade, and where considerable control must be exercised over the composi- tion and homogeneity of the final product. 4. Soaking pits, where the ingots, which are the prod- ucts of either the Bessemer or Open Hearth Processes for making steel, are thoroughly heated for finishing into final shapes for the market. To make these ingots, the metal produced by either of the above processes, is cast in an iron form in which it is allowed to cool until it has at- tained a certain amount of rigidity. Then the ingot and form are taken to a stripping machine where the form is removed and the ingot is then placed in the soaking pit to be thoroughly and evenly heated before being sup- plied to the finishing rolls. In all of the processes except the soaking pits, coal is chiefly used, but in the former, either natural or producer gas are the fuels. In the types of metallurgical furnaces now to be dis- cussed no smoke is made, but considerable dust, and large quantities of highly colored fumes are given off. The blast furnace, which is used for the manufacture of pig iron, employs coke as the fuel, and limestone is added to carry off the various impurities of the ore and fuel in the form of slag. The main inconvenience to the surrounding com- uosua puv （O ‘H Âq oqoqa |-|× ſaeae ：： - *sº， u.a. ng ſeo， uniteņøuu Jo pooquoqųºſºu uſ uoſºſ pudºxxHous-LI ºlimºſ） 63 SOME ENGINEERING PHASES 65 munity due to this process is caused from the ore and limestone dust carried out from the stoves in which the air for the operation is heated. To heat these stoves the gas from the furnace is used. In the Bessemer Process for making steel, the molten pig iron from the blast furnace is charged into a con- verter; the charge is changed to steel by blowing air through the molten mass and simultaneously removing the impurities. The process is fundamentally as follows: The impurities of the iron combine with the oxygen of the air and furnish the necessary heat to keep the charge of pig iron molten and allow its transformation into steel. It is during the early stages of this process that there is an emission of heavy fumes, which are discharged at low levels. In the Open Hearth Process for making steel, the molten pig iron from the blast furnace is charged into a type of Seimens Regenerative furnace where the charge is melted down and changed to steel. Either natural or producer gas is the fuel used to furnish the heat neces- sary. The impurities of the iron are flushed off in the form of slag. In the early stages of this process, fumes are emitted, usually of a yellowish color. These furnaces are usually provided with tall stacks so that the dust and gases are discharged at a considerable height above the surrounding territory. The foundry cupola is very much used to melt the pig iron for castings where the grade of the finished product need not be of such high quality and uniformity as that produced by the hot air furnace. This type of furnace uses coke as a fuel and limestone as a flux to remove impurities. No smoke and not a very great amount of fumes are the result of the operation of this process. Until recently, all puddling and mill heating furnaces were exempt from the Pittsburgh Ordinance regulating the emission of smoke. During one stage of the puddling process, the conditions are unfavorable for smokeless op- eration, and this fact has always been the basis for the most formidable arguments against smoke abatement. The 66 THE SMOKE INVESTIGATION puddling furnace is a simple reverberatory furnace fired from one end and having an opening in the side for charg- ing and working the iron. The puddling furnace is usu- ally fired by hand, uses large size bituminous coal, and has inexpensively constructed grate bars. The Puddling Process is usually divided into four stages in the order in which the various operations are carried Out. In the first stage, the heated furnace after having been charged with pig iron and hammer slag is made as air- tight as possible by closing all the doors. During this first stage the fire should be kept as hot as possible and with due care no smoke should be emitted. As soon as the iron has been completely melted this stage is finished. During the second stage, a maximum heat and oxidiz- ing atmosphere must be maintained in order to aid in removing impurities. On account of the construction of the furnace with ample refractory surface, and because of the intense heat developed, conditions at this stage are ideal for smokeless operation, and such should remain so unless the furnace is very carelessly operated. The object of the third stage of the process is to bring “On a boil of the metal” in the furnace. To do this the temperature of the furnace is lowered by closing the damper in the stack, and filling the furnace with an at- mosphere of smoke. Closing the damper results in the burning of the fuel on the grate with insufficient air and causes smoke. At this stage the process is a smoky one, although with the exercise of care on the part of the op- erator, and by application of some of the forms of stokers now on the market, the amount of smoke made should be appreciably decreased. It is also claimed that an oxidizing atmosphere during this stage would be detrimental to the quality of the finished product. In the fourth, and last stage, a welding heat must be used to form the iron into balls, so that it can be con- veniently worked under the hammer to be reduced to sizes suitable for reheating and finishing. Here, again the exercise of a moderate amount of care in the operation is SOME ENGINEERING PHASES 67 necessary in order to avoid producing smoke. With the increased use of steel, and its replacement of wrought iron, the puddling furnace rapidly gave way to furnaces for the manufacture of the former. It seems, however, that the use of the puddling furnace has decreased about as much as it will for some time to come, and that the problem of eliminating smoke from this source should receive more study than it has in the past. Heating and reheating furnaces are usually fired with coal and by hand, however, in some cases either producer or natural gas is used. In other cases the mechanical stoker has been very successfully applied to these furnaces. When hand-fired directly with coal, the process is inter- mittently a smoky one. In cases where the stoker has replaced hand-firing, smokeless operation is obtained and it is claimed that it resulted in an improvement of the quality and an increase in the quantity of the finished product from the same furnace. On account of the de- crease in the available supply of natural gas, its use as a fuel as applied to these processes is limited. A discus- sion of the merits of powdered coal for metallurgical pro- cesses will be found under Appendix II. For hot air furnaces, which are another type of re- verberatory furnace, the same statements will apply as were made for the heating and reheating furnaces. When using coal, stoker firing is much to be pre- ferred over hand-firing with any of the types of furnaces mentioned, for the following reasons: First, excess of air can be decreased to a minimum resulting in less waste of iron due to oxidation ; second, a more even and uniform temperature is maintained and the importance of the per- sonal factor decreased; third, a higher temperature and increased life of the furnace are the result of this steady application of heat and the elimination of a periodical ad- mission of large quantities of cold air; and fourth, in- creasing the intensity of the heat will result in a decrease in the time the metal must remain in the furnace, thus increasing the output. After the ingot has been stripped, as previously de- 68 THE SMOKE INVESTIGATION scribed, the metal has become too much cooled to permit of its being sent to the rolls for finishing or rolling into smaller size so that it must first be sent to the soaking pits for treatment. The function of the soaking pit is as the name implies, “to soak an ingot in heat” so that it will have a uniform temperature throughout and that the whole mass of metal shall have attained the same degree of plasticity before it is sent to the rolls to be reduced to various sizes and shapes. From six to ten ingots are placed in one compartment of these soaking pits at each charging. These soaking pits consist of long trenches usually placed below the floor level and are lined with firebrick. They are deep enough so that an ingot can be stood on end and a door or cover slides over the ingot with- out interference. This cover, which is lined with firebrick, is so constructed that it will slide back and forth on rollers to allow for placing the ingots in the pit. The universal fuel used to heat these pits is gas, either natural or pro- ducer, and although gas is used as the fuel, these pits are the source of considerable smoke. They did not until recently, however, come within the scope of the existing ordinance, and, as they represented a very small per cent. of the plants producing smoke, very little study has been made of this phase of the subject. Furnaces for burning brick and terra cotta are very smoky in their operation, especially during the drying out and baking process of the product. However, at the later stages of the process, when the vitrifying of the product commences, the operations may easily be carried out with- out the production of smoke. The smoke can only be elim- inated at the earlier stages of the process by the use of some other fuel than Pittsburgh coal, or by some method of precipitating the carbon and tarry products. of the Smoke. There are in operation in this District a considerable number of ovens for making coke. These ovens smoke al- most constantly, although the smoke at any one time is no denser than 60 per cent. black. The elimination of smoke from this course presents no serious difficulties as ·ųäinqs ſqq.I. Jo uoņºs aouapſsºu e uſ »， ſouoooi umoj ºxious—81 º inºſºſ "- 69 SOME ENGINEERING PHASES 71 the gases leave the Ovens at high temperatures and are conveyed by long passages to the stacks where they are discharged. There should be some remuneration result- ing from the complete combustion of these gases by per- forming useful work before they are discharged into the atmosphere, and if such were done, smokeless operation could be obtained. It is probably only a question of time until these antiquated coke ovens will be replaced by by-product coke ovens, which, while costly to install, are in the long run more profitable than the older forms, and which give no Smoke, RAILROADS. Second in importance to the smoke problem of the manufacturing plants is that of the railroads. The smoke from railroads is much more objectionable on account of the low levels at which it is discharged and the large amount of cinder and sparks emitted with it. On account of these conditions in the District, the amount of damage done by the smoke from railroads is a higher percentage of the damage by smoke from all sources than the smoke made by railroads is of the total smoke produced. The smoke from locomotives is discharged at roundhouses in the vicinity of terminals, freight and warehouses, manu- facturing plants and mills, and is usually trailed after the train over the right of way, and the immediate surround- ings. Cinders and sparks are for the most part deposited On the company’s own property, but in many instances are carried to some distance from the right of way. (See Figure 18.) The problem of abating smoke and decreasing the amount of cinder discharge from the stacks of locomotives has been one of the foremost problems confronting rail- roads for some time. Because of restrictions inherent in the design and operation of locomotives, the problem has been more difficult of solution than that of the stationary plant. In a locomotive the size of the firebox is restricted, and therefore the grate area upon which to consume the 72 THE SM OKE INVESTIGATION amount of coal to be burned in order to develop the requisite power is very small. In a stationary plant, the size of the grate is limited only by difficulties in construc- tion. With a locomotive the grate cannot be any wider than the gauge of the track will allow, or any longer than the distance a man can throw coal, which is now usu- ally taken to be about 9 feet. In a locomotive, coal must be consumed at from three to six times as rapidly as in stationary plants. This necessitates the use of a powerful draft. To supply this draft, the exhaust steam from the cylinders is discharged directly into the stack. Although it allows a high rate of combustion, this intense draft increases the dirtiness of operation in that it carries large quantities of fine coal, ash, and partly ignited fuel through the flues and discharges them through the stack as sparks and cinder. Especially is this the case with quick burn- ing friable coals, or when fuel containing considerable slack is used without wetting the same. Firebrick arches are now usually supplied on locomo- tives over the back end of the firebox. These arches aid materially in maintaining high furnace temperatures, mix- ing of gases, and in some sense, making the furnace regen- erative. Elaborate baffles cannot be applied, or large combustion chambers obtained, as with the stationary plant. This is due to the rough service such as vibration to which the locomotive is subject, and the restricted amount of space available. When using bituminous coal, especially those of high volatile content, the railroads are required to depend on one of several methods for smoke elimination: First, increased care in firing and proper equipment; second, the application of the mechanical stoker to the locomotive; and third, the steam jet. By all means the most efficient methods of prevent- ing smoke in a locomotive is to have a careful and alert fireman. He is a greater factor in preventing smoke than the coal or equipment of the engine. A careful fireman can take a poorly equipped engine supplied with inferior coal and make less smoke and dirt than a careless fire- man with a locomotive equipped with every possible de- SOME ENGINEERING PHASES - 73 vice and the best coal. When hand-fired, the amount of smoke, sparks and cinder discharged by locomotives de- pends even more on the care exercised in firing than on the equipment of the engine. The amount of Smoke and cinder discharged can be materially decreased by using low volatile, high grade, bituminous coals. Coke has also been supplied for use in locomotives in districts where smoke is especially objectionable. Two different types of mechanical stokers have been applied to locomotives. The first consisted in placing a device in the locomotive which scattered or sprinkled the coal over the grate. This type caused more smoke than hand-firing, and considerable difficulty was experienced in maintaining an even fire and constant steam pressure. The second method of eliminating smoke was an applica- tion of the underfeed principle in feeding the fuel, and better results have been secured than with the first type. A stoker of this type has been designed and placed in op- eration known as the Crawford Stoker. Quite a number of locomotives now entering the city are equipped with this stoker. With it the fuel is rammed into retorts, placed lengthwise of the firebox. Here the fuel is ignited. It then rolls or falls onto grates at the sides of these re- torts and is completely burned. Tests with this stoker show that only brown smoke is emitted in road operation. When the grates are shaken or the fire hooked, smoke will be emitted, yet the period is of not as long a duration as when these same operations are carried out with hand- firing. Observations in a double headed train in road oper- ation, one locomotive hand-fired, the other stoker-fired, showed an average of 60 per cent. black smoke for the for- mer, and 20 per cent. black smoke for the latter. The re- sults obtained from this stoker can hardly be said to have exceeded those attained by skilled hand-fired practice, but will far surpass the average hand-fired practice in economy and smoke elimination. The almost universal fuel used in locomotives Operat- ing in the city is Pittsburgh coal. The utmost care must be exercised in the handling of this fuel in locomotives 74 THE SM OKE INVESTIGATION in order to keep the smoke and cinder discharged within reasonable limits. This is true because this fuel ignites readily when charged to the furnace and causes very hot fires. As a result of a very extensive study, the Smoke In- spection Department of Chicago stated : * “The experi- ence of the Smoke Department has shown that there are no patented smoke devices which may be applied to loco- motives which are successful in preventing smoke. The best equipment that a locomotive may have for this pur- pose consists of: First. A strong and efficient steam blower in the base of the smoke stack. This blower pipe should have at least 11/4 inch steam connection and should be so equipped with valves that either the engineer or fireman may use it. This is for the purpose of supplying draft when the locomotive is not running. This blower should always be used when the engine stops and the fire is in such condition that smoke will be made unless there is a strong draft. Second. A brick arch in the firebox. This arch is for the purpose of giving a high temperature to the firebox and causing the gases to mix well with the air while in that part of the firebox where the temperature is high enough for combustion. Bulletin No. 2 issued by the Smoke Department goes into the question of brick arches in detail. Third. The fireboxes should be equipped with com- bustion tubes. These consist of tubes about 2 inches in diameter extending through the water space on each side of the firebox which admit air above the level of the fuel bed. Depending upon the size of the firebox, from five to six tubes of this sort should be placed on each side. A current of air through these tubes is insured by blowing a small jet of steam through them by means of a pipe about 1/3 inch in diameter.” 1 Report of the Department of Smoke Inspection, City of Chicago, February, 1911. SOME ENGINEERING PHASES 75 The topography of the city affects materially the op- erating conditions of the railroads and complicates the problems of smoke elimination. The various terminals of the railroads are situated not far from the junction of the two rivers and at comparatively low levels. Practi- cally all trains leaving the city and going eastward are required to ascend heavy grades and pull around sharp, or long, sweeping curves. It is necessary to exert a heavy pull from the time a train starts until it has passed be- yond the city limits. This necessitates heavy firing and is responsible for a large amount of smoke and cinder. All of the roads leaving the city have their tracks along the base of hills or in valleys between the hills. The contour of the District is such that there is a tendency to pocket the smoke and cinder in the valleys, or deposit them over residential sections immediately overlooking the same. Residents located on the top of the hills suffer heavily from the smoke made by locomotives in the river valleys. In every case where a railroad passes a city park the grades are steep for outgoing trains. This calls for heavy firing, and very often the aid of a pusher locomotive to help freight trains over these grades. It is in these cases that coke has been supplied for fuel, especially in the pusher locomotives. Some coke is used, however, in districts where the smoke is especially objectionable and cannot be eliminated entirely when using coal. The topog- raphy of the District, however, is very favorable for smoke- less operation of trains entering the city and coming from the East. It is not an unusual thing to note a heavy westbound train entering the city and operating with a clean stack, largely due to its coasting down grade under its own momentum, while a light eastbound train leaving the city may be emitting dense clouds of smoke. There are operating within the city limits of Pitts- burgh, five different Trunk Line Railroads: The Penn- sylvania Railroad Company, the Pittsburgh & Lake Erie Railroad, the Baltimore & Ohio Railroad, the Buffalo, Rochester & Pittsburgh Railway, and the Wabash Rail- road. -- 76 THE SM OKE INVESTIGATION In order to enable us to obtain some idea of the amount of coal burned on locomotives entering or leaving, and passing through the city limits daily, a circular letter was sent to the various companies operating lines enter- ing the city. As a result of this letter the following in- formation was obtained: Not Passenger Freight Classified Average number of locomotives . entering and leaving the city limits daily, 429 460 107 Probable tons of coal burned while within the city limits 450 830 Number of tons of coal put on . engines in Pittsburgh daily, 1,570 1,325 410 Average number of shifting en- gines operating within the city limits daily, 63 Probable pounds of coal burned per hour by each locomotive Of this class. 600 No data was officially supplied the Investigation as to the number of switching engines using coke, conse- quently no figures can be given for this fuel in this par- ticular kind of Service. The number of different locomo- tives, and the total number of locomotives entering and leaving the city are not the same, because, when a loco- motive entered and left the city more than once daily, each time it entered and left the city it was tabulated as “one locomotive entering and leaving the city.” This tabulation is made necessary, as many local passenger trains make several round trips daily, and cover short distances only. There is burned daily on locomotives, while within the city limits, approximately 1,700 tons of fuel, of which at least 95 per cent. is Pittsburgh bituminous coal. Much of this coal is burned in the locomotives in the round houses while starting up fires preparatory to road runs. At present not many of the locomotives of the District are SOME ENGINEERING PHASES 77 equipped with combustion tubes for introducing air over the fire, although most of the locomotives have firebrick arches. To handle this amount of Pittsburgh coal daily on these different locomotives requires the utmost care in operation in order to keep the amount of smoke made with- in reasonable limits. Among the worst smoke offenders, and presenting a very difficult problem for solution are the round houses. Some of the larger round houses, when they were installed, were well outside the city limits. However, due to the growth of the city, the residential portions now immedi- ately overlook them and suffer heavily from their smoke and dirt. There are eight railroad round houses located within the city limits, as follows: Railroad. Location. No. Of Stalls. Pennsylvania—Near Columbus Ave. & Marquis - St., Allegheny, 41 Pennsylvania — Twenty-eighth St. & Liberty Ave., 22 Pennsylvania—Forty-eighth St. & Allegheny River, 9 Pennsylvania—Thirty-second & Carson Sts., 20 Pennsylvania—McFadden St., Allegheny, 9 B. & O.-Near Melancton & Dyke Sts., Glen- wood, - 25 B. & O.-Forty-third St. & Allegheny River, 3 B. & O.-Foot of Corey St., Allegheny, 11 The total of eight round houses, located in the city proper, contain one hundred and forty stalls. Ilocated in the District and within a distance of from 41% to 81% miles from the city, there are five round houses in active use containing ninety stalls. The fueling of locomotives, the building of new fires, and the cleaning of fires, is neces- sarily a dirty and objectionable operation at best, and, as this work is usually done at the round house or in its vicinity, the difficulty of eliminating smoke from this source is apparent. 78 THE SMOKE INVESTIGATION Coke has been used while firing up, and backing the locomotive out of the round house, but on account of the character of the fumes discharged, its use has been dis- continued. This was due, largely, to the inability of the men to work in, what was in all probability, a poisonous atmosphere. In some sections of the country, in order to eliminate the smoke at round houses, the railroads have erected high stacks to which the stack of the locomotive is indirectly connected while being fired up. This high stack or chim- ney creates the draft for building and maintaining the fire until steam pressure has been raised. In order to eliminate the nuisance from the objectionable particles of the smoke it is customary to conduct the smoke through a washer so as to remove the carbon and tarry particles from the gases before they are conveyed to the chimney and discharged into the air. The use of combustion tubes in locomotives should aid materially in the elimination of smoke, when starting new fires, and rebuilding old ones after they have been cleaned. This method allows ample air to be introduced over the fire at times of greatest need. The time to get up steam could be reduced and therefore the amount of smoke might be materially decreased when starting new fires, by filling the boiler with hot water as close as possible to 2009 F. STEAMBOATS. The rich bituminous coal fields of the District have their outlet to the South through Pittsburgh, by way of the Allegheny, Monongahela and Ohio Rivers. Pittsburgh is the natural harbor where the boats which are used for towing the coal to the Southern ports tie up during un- favorable stages of the river. The coal is brought from the mines in barges and pooled at Pittsburgh to be shipped South. The smoke due to this source is chiefly produced by boats handling this coal, making up fleets for ship- ment, towing and arranging empty barges to be sent back to the mines, and in supplying fuel by barge to the various "uøaſ XI e ſºubº uouo IV º qq uo quoqueºļS–61 ºunºſ） |× ， ！ſ');|- |\;\!ź | ſºſ， ſ) / \ }(|\W\\ {， .， ………. -- $/^\|\}/{} =--- - - ºſº 79 SOME ENGINEERING PHASES 81 industries of the city for power and manufacturing pur- poses. Only a small portion of this smoke comes from the boats engaged in passenger and freight traffic. (See Figure 19). This is accounted for by the fact that only a few boats are now engaged in passenger and freight traffic upon the rivers. During unfavorable stages of the river, all passenger and freight traffic is discon- tinued, this usually occurs in the latter part of the summer and early fall. The boats engaged in shifting tows about the river and supplying local needs for fuel are inveterate smokers. They produce considerable annoyance, incon- venience, and loss to the office buildings situated along the river front, to occupants of these offices, to pedestrians using the bridges connecting Pittsburgh proper with Alle- gheny and the South Side. In times of high water and favorable stages for coal shipment, the rivers are a scene of very much activity lasting from several days to one or two weeks. These activities consist in the shifting of tows, and the firing up of the large boats, the latter being responsible for the emission of quantities of black smoke. The equipment of these boats usually consists of old style two-flue, or horizontal return tubular boilers, fired by hand with large size bituminous coal. The shell of the boiler is exposed directly to the action of the flames and the distance from the grate to the shell is very short. The firemen employed on boats represent the poorest class. The enforced periods of idleness and the temporary high wages paid appeals to this type of shiftless individuals. Although the fireboxes are not so much restricted as those of a locomotive, yet there is not enough space avail- able on these boats to install special methods of furnace construction to aid in increasing efficiency and smoke elimination. The present type of installation in use on these boats can only be operated, without the emission of black smoke, by using a high grade low volatile coal, extreme care in firing, and some provision for a secondary air supply at time of firing. 82 THE SM OKE INVESTIGATION As a majority of the boats on the rivers in this vicin- ity, and all the boats engaged in towing coal to the Southern ports, are the property of the various coal com- panies which have their headquarters in the city, it is logical to expect that they would use the high volatile smoky coal of the District. The firemen employed are careless and are picked up regardless of all other qualifica- tions than physical fitness. They have no promotion or better position to look forward to, as do the locomotive firemen. Furthermore, efficiency or smokeless combustion is of little consequence to men of this type, and at the best, most of these so-called firemen are only coal shovelers. Their only aim is to supply enough coal to the furnace to keep up sufficient steam pressure, regardless of the amount of smoke made or the fuel required. The size of fuel fired and proper methods of firing have no significance with them. Especially is this true of the larger tow, pas- senger and freight boats, the operation of which is entirely dependent upon a favorable stage of the river. The diffi- culties, however, do not rest entirely with the method of firing. The equipment that these men are compelled to handle cannot possibly be operated without the emission of dense smoke, when fired by hand, even by expert fire- men using Pittsburgh bituminous coal. Very little study has been given to this phase of the subject and until some effort is made in this direction and advice is given to aid in abating this nuisance, the firemen should not be held entirely responsible. Up to the present time no efforts have been made to apply the mechanical stoker to boats of this class. If these condi- tions were fully recognized in the original design, there should be no reason why certain types of stokers would not lend themselves readily to application on these in- stallations. It would seem that unless a low volatile bituminous coal is used, the solution of this problem must depend upon the stoker. The use of low, volatile bituminous coal, as fuel on the boats, would in itself have a direct tendency to decrease the amount of smoke. Wasteful firing methods would have to be discontinued SOME ENGINEERING PHASES 83 when using this more expensive fuel, and any increase in care of firing has a direct bearing on the elimination of smoke. RESIDENCE SECTION. Under the “Residence Section” are included apart- ment houses and all residences using bituminous coal for domentic purposes, or for heating. A comparatively small amount of smoke comes from the apartment houses of the city. Except for the very large apartment houses which furnish their own power, and power to some of the buildings in the neighboring districts, these buildings are equipped with heating plants only, in which natural gas is the fuel used. In the buildings of this class where power is also furnished, the boilers are usually fired by hand with Pitts- burgh coal. In some of these instances, however, me- chanical stokers are installed and the operating conditions are usually very good. More care and proper supervision of the original design and lay-out of plants is needed, as installations are quite frequently constructed without much provision for efficient and smokeless combustion. The breechings are often long and tortuous containing many sharp angled bends, or are so located that they are practically inaccessible. The boiler capacity installed is usually ample to carry the required load without forc- ing. Much care should be exercised in choosing the size of fuel which lends itself to the best operation, as regards a minimum production of smoke. Large size fuel, or screened coal of the smaller sizes entirely free from slack, is generally used. When heat alone is the requirement, and natural gas is not used as fuel, these installations produce much smoke and soot. Boilers used for heating purposes are of the cast iron sectional type, and do not adapt themselves readily to smokeless operation unless constructed on the down draft principle, and using the better grades of bituminous coal. In a residential furnace smokeless operation is dif- ficult, as most of the carbon and other tarry volatile 84 THE SM OKE INVESTIGATION products, contained in the volatile portion of the fuel, are carried off as smoke or are deposited as soot in the pas- sages to the chimney. From the chimney the soot is emitted periodically in large flakes and deposited over the imme- diate neighborhood. These conditions, however, present one source of smoke in which the producer is the heaviest sufferer. This is due to the fact that most of the smoke and soot are usually deposited on the producers own property and because they are emitted at low levels and are not carried very far away. The amount of smoke from this source becomes negligible with the return of warmer weather, as natural gas is the universal fuel for domestic purposes, other than heating requirements. Coke and anthracite fuel can, however, be easily burned in most any sort of furnace for this purpose without the emission of smoke. In all residences, where bituminous coal of this District is used for heating purposes, much smoke and soot is the result. MISCELLANEOUS SERVICES. There are many minor sources of smoke in the city which help to swell the total amount of smoke, such as municipal and contractor’s engines, tar and asphalt heaters, etc. These make smoke in the streets and dis- charge it at low levels, near doors and windows. Smoke from these sources is most annoying and is the cause of many complaints, for it probably causes more relative damage than other smoke emitted at higher altitudes. A strict enforcement of the city smoke ordinance would soon force the owner of such engines to burn a low volatile coal. SOME ENGINEERING PHASES 85 Part V. Mechanical Engineering Survey of Stationary Plants. THE OBJECT OF THE SURVEY. The term “stationary plants” includes power and heating plants, mills, and factories. It refers to plants stationary in character as distinguished from the portable power plants in boats and locomotives, of which no par- ticular survey has been made. The object of the survey of stationary plants was to determine what are the typical conditions under which coal is burned in the Pittsburgh District; to describe and point out the merits of the different mechanical devices which are in use in the District; and to show how they work in actual practice, or, perhaps better, under the con- ditions under which they are installed. METHODS OF COLLECTING DATA. In making the survey, one hundred and fifty-two typical stationary plants were visited for the securing of certain data and for observations as to smoke conditions. Examinations were made of these plants and the data secured, which is given in the tables of the Survey of Stationary Plants. In so far as the data or information was known, it was, in almost all instances, made available for the purposes of the Investigation, by the managers, engineers, or plant operators. The plants visited were classified under five general headings: 1. Hand-fired plants. 2. Plants equipped with Chain Grate Stokers. 3. Plants equipped with Front-feed Stokers. 4. Plants equipped with Side Over-feed Stokers. 5. Plants equipped with Underfeed Stokers. 86 THE SMOKE INVESTIGATION SMOKE, OBSERVATIONS. In order to make results of this Investigation com- parable with the results of other Investigations, and to conform with the practice universally used throughout the country, and adopted by this city, the Ringleman system of estimating the relative blackness of the smoke issuing from stacks was adopted as a standard. This system has been adopted by the Federal Bureau of Mines and is clearly explained in the transactions of the American Society of Mechanical Engineers, Vol. XXI, December, 1899. The Ringleman scheme and the method of calculat- ing the percentage of density of smoke will be found under Appendix III. EIAND-FIRED PLANTS. Hand firing, which has been practiced from very early times, consists of charging the coal into the furnace at various intervals by hand and in amounts varying with the service to be rendered. The fuel bed is evenly covered with fuel and the coal is fired in small quantities at given intervals and according to one of three methods. In the spreading method each door of the furnace is fired at one firing and the fuel is spread evenly over the entire grate area. In the alternate method where there are two doors to each furnace only one door is fired at each firing in order to cover, at any one time, one-half of the grate sur- face with green fuel. The firings are made at equal inter- vals of time. The fuel is spread evenly over the portion of the grate fired. When a furnace has three doors, the usual plan is to put fresh coal on the front half of the grates fed by doors one and three, and on the rear half of the grate fed by door two. Then, at alternate inter- vals, supply fuel at the rear of numbers one and three grates, and on the front half of number two grate. This method of firing insures that one-half of the grate surface is at all times free from green coal. Furthermore, it has the advantage over the spreading method, where a hori- zontal flow of the gases is employed, in that one-half of SOME ENGINEERING PHASES 87 the fuel bed is in an incandescent state while the volatile products are being distilled from the freshly fired fuel, this aiding to complete combustion of these products. Means should be employed to promote a thorough mixing of the air and the volatile gases at all parts of the fuel bed and the combustion chamber. This mixing process cannot be easily accomplished, when the vertical style of baffling is employed, hence the alternate method of firing has no particular value with this style of baffling. In the coking method, the fuel is charged on the dead plate immediately inside of the firing doors, remaining there until all the volatile products are distilled off, then it is pushed to the back portion of the furnace with a scraper and fresh fuel again charged on the dead plate when more coal is needed. The back of the furnace must be kept at a white heat at all times. With this method air should be admitted over the fire, especially at times of firing, and the grates should always be kept well covered. When used with the horizontal type of baffling this method has the advantage of compelling all gases, distilled from the fresh fuel charged at the front of the furnace, to pass over the bed of incandescent carbon, this tending to complete combustion before they are cooled below their ignition temperature. This method is inap- plicable when the flow of gases is vertical instead of hori- zontal, and is not much used now as a very good fireman is required to get satisfactory results with it since the steam gauge and fire require more attention than the average fireman is liable to give them. Another serious objection is that the fire requires entirely too much stir- ring and raking. The spreading method of those described is most generally used and lends itself more readily to varying conditions, it being the only method usually con- sidered when the vertical type of baffling is employed. In order to obtain efficient operation and smoke elimination with a hand fired furnace, the utmost care must be exercised in firing, and in the use of the furnace auxiliaries. In connection with hand-fired furnaces there are quite a number of auxiliaries which, when properly in- 88 THE SMOKE INVESTIGATION stalled and operated, tend to decrease the amount of Smoke made, and if a low volatile fuel is employed, smokeless operation can be obtained. These auxiliaries are usually classified according to the manner in which they are ap- plied to the furnace. The first of these, so called furnace integrals, involve changes in the design and construction of the furnace and boiler setting and consist of such addi- tions as Dutch ovens, fire tile, wing walls, piers, enlarge- ment of combustion chamber and changes in method of baffling. The second consists of those devices which can be applied to any furnace without much change, such as steam jets with or without the admission of air over the fuel bed. The best results have been obtained when com- binations of the first and second classes have been used. With hand-fired furnaces, care in the manner of firing is of prime importance, and upon it too much emphasis cannot be placed in order to secure efficient and smokeless operation. There are factors associated with the hand- fired process due to which it does not adapt itself readily to smokeless operation and it is only by increased care in the manner of firing that the effect of these items can be minimized. In the hand-fired process, furnace doors must necessarily be opened to charge the fuel and attend fires, allowing simultaneously large amounts of cold air to be drawn into the furnace, thus decreasing the furnace temperature. Large amounts of gas are evolved at the time of firing the fresh fuel. On account of the decreased furnace temperature it is, at the same instant, most difficult to obtain complete com- bustion of the volatile gases. The common tend- ency among firemen is to fire as infrequently as pos- sible, using a large amount of fuel at each firing, and with- out any regard to distributing it evenly over the entire grate. The hook and slice bar are liberally applied and very little care is usually exercised in their use. The length of time the doors are required to be kept open may be considerably decreased by firing fuel in smaller quanti- ties, and using care to spread the fuel evenly over the grate at each firing. This eliminates the liberal use of the hook SOME ENGINEERING PHASES 89 and slice bar, keeps the fire in better condition and serves to eliminate Smoke. The tendency in hand-fired plants to use large sized coal entirely free from slack results in the production of large quantities of smoke. It requires less draft to burn this fuel than when some slack is mixed with it, although the fuel without any slack, gives a more intense fire. Sufficient attention is not given to the size of the fuel fired, and lumps of too large a size are used causing bad spots in the fire, necessitating liberal use of the hook and simultaneously causing smoke. There is also a common tendency among firemen to fill holes in the fire with fresh fuel instead of first raking incandescent fuel into these d | º §%2. à % 2022222 º % _-_T L % º § H N Rizzº }% - ZzZ2% N Sºğ % Figure 20–3}utch oven setting as applied to horizontal return tubular boiler. SS º holes and then charging the fresh fuel. Directions for proper methods of firing are given in Appendix III. Using a low Volatile coal in a properly constructed furnace and following these directions, smokeless combustion and high efficiency will be obtained. A Dutch oven as illustrated by Figure 20, when properly installed, provides one of the simplest methods of obtaining large coking area per square foot of grate surface. Such a furnace will produce very high tempera- tures when operated under the proper conditions. Although much better than the ordinary setting, the plain Dutch oven is too limited in length to prevent smoke for- mation except at very light loads, especially is this true 90 THE SMOKE INVESTIGATION when applied to horizontal return tubular or vertically baffled water tube boiler, unless ample combustion Space is provided. The combustion space is usually somewhat restricted and the velocity of the gases too high to permit of a thorough mixture before complete oxidation can take place. Steam jets, described later, placed across the front or along the sides of the furnace, and blowing steam and 2% % % Figure 2 #-Kent’s wing-wall furnace as applied to Babcock & Wilcox water-tube boiler. air over the fire, are effective in mixing air and the com- bustible gases, also, an increase in the length of time the combustible gases are held in the furnace, will aid ma- terially in decreasing the amount of smoke made. The best results have been obtained by modifying the construction of the furnace so that the combustion space will be increased and extra baffles introduced to vary the direction and increases the length of travel of the gases before they become cooled. For best results these aux- SOME ENGINEERING PHASES 91 iliaries should be used in connection with the Dutch oven and steam jet, as previously explained. The Dutch oven as applied to a B. & W. boiler sup- plemented with the installation of baffle piers known as Kent's wing-walls are shown by Figure 21. The purpose of these baffles being to increase the amount of refractory Z. | 2ZZºº T Ø | ZZZZZZZZZZZZZZZZ º all ſº ) % r1 >~ Z - G NNNNNNNNNNN N <& z z Figure 22–Wooley furnace applied to Babcock & Wilcox water tube boiler. surface and length of travel of the hot gases. The piers and additional brick work acting as a regenerative fur- nace, absorbing heat when the fire is hottest and giving it up when fresh fuel is charged. A modification of this furnace known as a Wooley smokeless furnace is shown as applied to a B. & W. boiler, Figure 22. The principal features of this furnace is the 92 THE SMOKE INVESTIGATION provision of ample refractory surface and the manner of deflecting and mixing of the gases to obtain complete oxidation before they become cooled. The dividing wall shown in the center of the furnace and the restricted open- ing at the bridge wall lend themselves to the attainment of good results from the alternate method of firing. The heat from one side of the furnace being available to aid in the combustion of volatile products which are being distilled from the freshly fired fuel. A horizontal return tubular boiler as usually installed is shown in Figure 23. This type of setting has little in its favor outside of the fact that it occupies the least º <2 Š & NZZZZ 7N ń.– Figure 23–Usual method of setting horizontal return tubular boiler. amount of space possible to develop the requisite power. It is cheap to install and has an extremely low up-keep cost. The combustion space is very much restricted. No provision is made to keep the gases at the proper tempera- ture until combustion is completed, all the principles of proper combustion being neglected in the construction of this setting. This type of setting typifies one of the most persistent smokers in use. Figure 24 illustrates an attempt to make some pro- Vision to maintain a high furnace temperature where the space available is very much restricted. This setting is much to be preferred over the one where the shell is ex- SOME ENGINEERING PHASES 93 posed directly to the fire as in Figure 23. When using the proper care, and a low volatile fuel, the amount of smoke made can be greatly decreased. The length of travel of the gases before they strike the cold surfaces of ~ y K1 ŻSEZZZZZZZZZZZZZZZZZ WZZ N N NN *27 2%2.%% º % ſ \ % • AA% N N N §§§ N N WN SN NNNSS %* 2 *% ...”%% 2 º 2. % % Zºº § § N ,” N N N 2 z º º% /. % 2 % Ż%RSSSSSSSS S$SEZ % 2% ~pº %2 % 2 * Figure 24–Horizontal return tubular boiler with fire-brick arch over grates and under boiler shell. 4 ZSºse-2222222222222222 zººs 2 O % º &2. §§2 S& Ü S º 27.2% º § § *śs |/| à & | tº § % NZZ ZZO º º §ssºwsº - º-ſº Tigure 25–Horizontal return tubular boiler with fire-brick arch over grates. the boiler is much too short, and unless steam jets are applied the gases do not remain in the furnace long enough and are not well enough mixed to be completely consumed before they are cooled below their ignition temperature. 94 THE SMOKE INVESTIGATION Figure 25 illustrates another type of setting wherein the Dutch oven effect is still obtained and more of the heating surface is exposed to the action of the hot gases, thus making possible the development of higher ratings. Figure 26 illustrates a Hawley down draft furnace applied to a Heine water tube boiler. This furnace has two sets of grate bars, the upper bars being formed of tubes through which the water of the boiler circulates. The lower bars are the ordinary type of bars used in any hand-fired furnace. In operation the coal is fired == | === FEF==== ==|| F= == ſ ę == iss= H C Hºf-ſe º Pt S : % | º ASW ºn S&ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ N N N = N º Tigure 26–Heine water-tube boiler equipped with Hawley down-draft furnace. on the upper grates and after being partially burned falls to the lower grate where it is completely consumed. The air for combustion passes down through the upper grates and up through the lower grates. The air and distilled gases from the fresh fuel are heated and intimately mixed in passing through the fuel bed and over the incandescent carbon on the lower grate, thus aiding complete combus- tion. Considerable care must be exercised to keep the upper grates well covered and prevent green coal getting through to the lower grates. SOME ENGINEERING PHASES 95 THE STEAM JET; ITS USE WITH HAND-FIRED FURNACEs. Steam jets are the devices in most common use in connection with hand-fired furnaces in order to obtain elimination of smoke. They may be classified according to the manner in which they are used. 1. Non-automatic steam jets: (a) Steam is used as a means of aspirating air into the furnace over the fire. (b) Steam alone is blown into the furnace over the fire. 2. Automatic steam jets: (a) Steam is used as a means of aspirating air into the furnace over the fire. (b) Steam alone is blown into the furnace over the fire. As applied to furnaces, steam jets are usually non- automatic and the degree of efficiency with which they operate is entirely dependent upon the fireman, the conse- Quence being that they are usually allowed to run longer than is required, or they are not used at all. Any steam jet that will properly mix the air and gases at the time of firing and also increase the length of time the gases are kept in the furnace will aid in the abatement of smoke. However, if the steam jets are allowed to operate longer than required they become a source of great waste of steam and will decrease the furnace efficiency, especially when air is aspirated into the furnace with the steam. The best results have been obtained when the air is aspirated with the steam into a furnace having a refrac- tory roof. When applied to an improperly designed fur- nace, or to one without ample refractory surface, the only purpose the steam jet accomplishes is to lengthen the time the gases are in the furnace and cause an intimate mix- ture of the air and gases. The steam jet is a very inex- pensive device to install, but all factors being considered, it is usually a very expensive one to use. The idea that the steam jet increases the thermal value of the fuel is 96 THE SM OKE INVESTIGATION erroneous. As much heat is required to dissociate a pound of steam into its elements, hydrogen and Oxygen, as is given off when they recombine to form steam. More- over, the fact must not be overlooked that it is extremely difficult to burn hydrogen in an ordinary furnace, so if some steam were dissociated, it is probable that some of the hydrogen would escape to the stack unburned. With hand-fired furnaces the automatic steam jet, which operates every time the door is opened for firing, slicing, or raking, and which is cut out of commission at times of cleaning is much to be preferred over the non-automatic jet in stationary practice. TABLE 4—Detail of data taken on hand-fired plants. Coal Stoker Furnace. Dimensions Feet and inches. No. of e Grate Instal- Commercial * Quantity Kind of Thickness | Frequency | No. Grate to H. S. Front Height lation Name Size per yr. Stoker of Fire of . Area Furnace Coking arch Length | Height Tons Inches Cleaning Width Length to Coking Arch Sq. Ft Front Arch | Rear Aver. Min Boiler Front Back Furnace 1 Pittsburgh Run of Mine | . . . . . . . . . . Hand fired 14-15 2in 24 hrs. 3 48.0 e tº g º g : é º e e e º e 8'-0" 6'-0" O None . . . . . . . . . . . . . . . . . 2 do Slack do 12 2 ” 24 '' 4 35.0 & e º e º a & sº e º e s tº 7'-0" 5'-0" O do . . . . . . . . . . . . . . . . . . . . . . 3 do do . . . . . . . . . . do 12 2 ” 24 '' 6 22.5 2'-3" ... . . . 4'-6" 5'-0" 0 do I. . . . . . . . . . . . . . . 4 do do 33,300 do 18–20 e sº e & e g = * * 4 70.0 3’-2” 2'-6" | 10'-0" 7'-0" O do . . . . . . . . . . . . . . . . . . . . . . . . . 5 do do . . . . . . . . . . do 12-18 l. . . . . . . . . . . . 2 53.7 1'-8" | . . . . . . . 10'-9" 5'-0" O do | . . . . . . . . . . . . . . . . . . . . . . . . . 6 do do . . . . . . . . . . do 12–18 . . . . . . . . . . . ." 4 53.7 1'-8" | . . . . . . . 10'-9" 5'-0" 0 do | . . . . . . . . . e is a tº s º e g º a s g º $ 6 & & 7 do 2" Nut . . . . . . . . . . do 18-24 4 '' 24 '' 6 64.4 6'-0" 4'-0" | 10'-2 6'-4" | . . . . . . . . . '-0 6'-5" 8’-9" | . . . . . . . . 8 do Slack 12,400 do 12-16 2 ” 24 '' 11 25.0 2'-0" | . . . . . . . 5'-0" 5'-0" O None l. . . . . . . . . * * * * * * * * * * 9 do Lump 27 do 4–8 Variable 2 25.0 3'-0" 2'-6" 5'-0" 5'-0" O do | . . . . . . . . . . . . . . . . . 10 do Run of Mine 3,000 do 8-12 4 in 24 hr 2 35.0 * & e < * 2'-6" 7'-0" 5'-0" O do | . . . . . . . . . . . . . . . . . . . . . . . . 11 do do | . . . . . . . . . . do 4-8 2 ” 24 '' 2 27.5 2'-4" | . . . . . . . 5'-6" 5'-0" 0 do 35.0 7'-0" 5'-0" 12 do do 100 do 8-16 1 ° 24 '' 2 27.0 2 º: " . . . . . . . 6'-0" '-6" O do [.. . . . . . . . . . . . . . . . . . . . . . . . . '- * to 13 do do 6,700 do 10–20 3 '' 24 '' 4 36.0 2'-9" 2'-6" 6'-0" 6'-0" 1'-6" do I. . . . . . . . . . . . . . . . . . . . . . . . 14 do Nut & Slack 900 do 3–5 2 ” 12 '' 1 42.5 e tº e º a e º is tº tº sº º 5'-0" '-6" O do | . . . . . . . . . . . . . . . . . Screened 15 do over $4 bar 1,500 do 9 2 ” 10 ” 2 42.0 2'-2" | . . . . . . . '-0" 6'-0" O do | . . . . . . . . . s & e º e g g g I e º º sº us e º 'º 16 do Nut 1,200 do 6 2 ” 24 '' 1. 28.5 5'-6" | . . . . . . . 6'-0" 4'-9" e s w tº tº e 4'-0" 4'-0" '-0" . . . . . . . . 17 do do 800 do 6 2 ” 24 °’ 1 22.75 5'-6" | . . . . . . . 6'-8" | 4'-11” tº e g tº gº tº '-0" '-0" 4'-0" | . . . . . . . . 18 Wood Shavings . . . . . . . . . . do 4–12 . . . . . . . . . . . 1 |. . . . . . . . . . . . . . . . . . . . . . . . 5'-0" e is º º 0 None . . . . . . . . . . . tº e º ſº tº tº e º ſº. Screened 19 Pittsburgh over 34 bar |. . . . . . . . . . do 4-12 1 '' 24 '' 1 |. . . . . . . . 2'-6" . . . . . . . . . . . . . . . . . . . * * * O do | . . . . . . . . . 20 do Run of Mine | . . . . . . . . . . do 12–18 2 ” 12 '' 1 14.6 & & & e º a tº 1'-4" 4'-6" 3'-3" O do | . . . . . . . . . . 21 do Slack 900 do 10 2 ” 24 '' 2 30.25 2'-6" | . . . . . . . 5'-6" 5'-6" O do | . . . . . . . . . . . . . . . . . . . . . . . . 22 do do 650 do 8 2 ” 24 '’ 1 27.5 2'-0" 1'-8" 5'-0" 5'-6" 0 do 1'-0" 23 do Run of Mine 884 do 8-12 2 ” 24 '' 2 27.5 2'-6" 2'-0" 5'-6" 5'-0" O do 1'-6" e 24. do do 260 do . . . . . . . . . . . . . . . . . . . . . . . 1 25.0 3'-0" 27-2" 5'-0" 5'-0" O do 1'-6" tº e s e º 'º º 25 do do 900 do 4-6 1 * 10 ” 2 37.5 3'-6" 3'-0" 7'-6" 5'-0" 0. do . . . . . . . . . . . . . . . . . . . . . . . . º «» e «» e «» º ● ● ● ● ● ● � � � & ſ） → „0”,/ ■ ■ ■ ■ & & es e se ſă º ſº ºs �■ ■ ■ & � � • • • • • § €. * • • • § € 497,3！ • • • • • „0”,9 „0”,9 * ， ， ， ， ， º • d & & & & © & & & & & & • • • • • • • x{oeq * ø ± ø § • & & & • • • O C « e » ø ø œ • • • • O C „0”,6 Go C G D * e ve & g & : o coo o o c C C C C C C C C C C C ld c c {{ r- CN r- r- coco CN r- CN CN CN co co Ao r— r- CO CN CN CN do OI-8 0I-8 *>{{I|,, 8-, , † ">{,,iffI-,,0I ZI «; • º «; & & & & & + & ZI 3ņeĮd peap DIO ZI-OI ZI ZI-9 ZI-9 8 03 8 x{Oleg 8-9 3ūOI I ZI 9 x{oeg„,9 4ūOJ, H ,,ZI ZI-OI 0I Op 3 LIȚIAI JO LITTRI Op >{OeĮS Op 3 uJWI JO LI nºſ © LIĻĻAI JO LI m>{ pĐųSnIQ Op Op Op 3 LIȚIAI JO LII??I >{OBIS ĐLIȚI \I JO u nºſ Op >{O eĪS 3 LIĻĻAI JO U nºſ >ſoeIS 32n N % ; op >{OleIS ? } n N >{OeſS Op 9 LIJN JO LIrl（{ đúIm”I 9 LI JAI JO O x{0æIS ? q n N ĐuȚIN JO ūnºſ Op q3 InqSĮ Į ĮGI ! ĐI:ąeĮOA AAO’T Op op Op· op Op op| 99 £ TABLE 4—Detail of data taken on hand-fired plants—Continued. Eoilers Load No. No. used to carry of Steam Instal- Builders No. Pressure lation Type Rated Instal- Aver. Aver. Lbs. per Requirement Nature Character H. P led. Heavy Light sq. in. Load Load 1 Heine Water Tube. . . . . . . . . . . . 650 3 3 1. . . . . . . . . 100 Power. . . . . . . . . . . . . . . . . . Uniform. . . . . . . . . . . . . Mfg. 2 Horizontal Return Tube. . . . . . . 500 4 4 |. . . . . . . . . 100 do . . . . . . . . . . . . . . . Variable. . . . . . . . . . . . . Mill 3 do . . . . . . . . . . . . 480 6 . . . . . . . . . . . . . . . . . . . 100 Power. . . . . . . . . . . . . . . . . . do . . . . . . . . . . . . . do 4 B & W. Water Tube. . . . . . . . . . 1,500 4. 4 |. . . . . . . . . 105 do . . . . . . . . . . . . . . . . . . do . . . . . . . . . . . . . do 5 2 Flue. . . . . . . . . . . . . . . . . . . . . . . 180 4 |. . . . . . . . . . . . . . . . . . . 115 do . . . . . . . . . . . . . . . . . . do do 6 2 Flue. . . . . . . . . . . . . . . . . . . . . . . 360 8 . . . . . . . . . . . . . . . . . . . 115 do . . . . . . . . . . . . . . . . . . do . . . . . . . . . . . . . do 7 Rust Water Tube. . . . . . . . . . . 1,740 6 6 . . . . . . . . . 135 do . . . . . . . . . . . . . . . . . . do . . . . . . . . . . . . . do 125 on 2 8 Horizontal Return Tube. . . . . . . 860 11 11 95 on 9 do . . . . . . . . . . . . . . . . . . Uniform... . . . . . . . . . . Factory 9 do 295 2 1 |. . . . . . . . . 100-150 do . . . . . . . . . . . . . . . . . . Variable. . . . . . . . . . . . . Mfg. 10 do . . . . . . . 300 2 2 . . . . . . . . . 100-110 do . . . . . . . . . . . . . . . . . . do ... . . . . . . . . . . . do 11 do . . . . . . . 200 2 2 |. . . . . . . . . 80 Power & heat. . . . . . . . . . . . Fairly Uniform... . . . Factory 12 do 185 2 1 |. . . . . . . . . 80 do . . . . . . . . . . . . Steady. . . . . . . . . . . . . . do 13 do 600 4 4 |. . . . . . . . . 100 Power. . . . . . . . . . . . . . . . . . O . . . . . . . . . . . . . . do 14 do . . . . . . . 65 1 |. . . . . . . . . . . . . . . . . . . 90-95 do . . . . . . . . . . . . . . . . . . Fairly Steady.. do 15 Erie City, Water Tube. . . . . . . . 400 2 2 . . . . . . . . . 90-100 Power & heat. . . . . . . . . . . . Variable... . . . . . . . . . . do 16 Stirling, Water Tube. . . . . . . . . . 150 1 1 . . . . . . . . . 100 do . . . . . . . . . . . Uniform... . . . . . . . . . . do 17 Munroe, Water Tube. . . . . . . . . . 100 1 1 |. . . . . . . . . 75–90 do . . . . . . . . . . . do do 18 Horizontal Return Tube. . . . . . . 45 1 . . . . . . . . . . . . . . . . . . . 30 Heat. . . . . . . . . . . . . . . . . . . . . do . . . . . . . . . . . . . . do 19 do º 100 1 . . . . . . . . . . . . . . . . . . . 100 Power. . . . . . . . . . . . . . . . . . do . . . . . . . . . . . . . . do 20 do . . . . . . . 120 2 2 40-80 Heat & emergency. . . . . . . . Variable... . . . . . . . . . . do 21 do . . . . . . . 150 2 2 . . . . . . . . . 40 Power & Heat. . . . . . . . . . . do . . . . . . . . . . . . . . do 22 do . . . . . . . 60 1 1 . . . . . . . . . 75 do . . . . . . . . . . . do ... . . . . . . . . . . . do 23 do . . . . . . 105 2 1 |. . . . . . . . . 90 do . . . . . . . . . . . do . . . . . . . . . . . . . . do 24 do 80 1 1 . . . . . . . . . 80 do . . . . . . . . . . . do ... . . . . . . . . . . . do 25 do . . . . . . . 240 2 . . . . . . . . . . . . . . . . . . . 100 Power. . . . . . . . . . . . . . . . . . do ... . . . . . . . . . . . Shop 26 do . . . . . . . 240 2 1 |. . . . . . . . . 140 do . . . . . . . . . . . . . . . . Uniform... . . . . . . . . . . Factory 27 do . . . . . . . 300 3 2 . . . . . . . . . 90 Power & heat. . . . . . . . . . . do ... . . . . . . . . . . Building 28 do . . . . . . . 200 2 2 . . . . . . . . . 100 do . . . . . . . . . . . . do ... . . . . . . . . . . do Round-house ldg. do do Heine Water Tube. . . . . . . . . . . . B. & W. do . . . . . . . . . . . . Water Tube. . . . . . . . . . . . . . . . . . Locomotive. . . . . . . . . . . . . . . . . . Horizontal Return Tube. . . . . . . O . . . . . . . 2 Heine Water Tube 1 Keeler do Locomotive. . . . . . . . . . . . . . . . . . Water Tube. . . . . . . . . . . . . . . . . . s & e º º is as Internally Fired Water Tube. . . 2 Flue. . . . . . . . . . . . . . . . . … Stirling do Horizontal Return Tube. . . . . . . O & & e º e º º do . . . . . . . Heine Water Tube. . . . . . . . . . . . Cahall do Horizontal Return Tube. . . . . . . & sº gº & e º 'º e º is is a * & & © a e º 'º e º e Locomotive. . . . . . . . . . . . . . . . . . Munroe Water Tube. . . . . . . . . . Horizontal Return Tube. . . . . . . Erie City Water Tube. . . . . . . . . 1 i * * * * * * * * * * * * * * * * * * * tº t e is sº e g º gº * * * * * * * * * * * * * * * g g tº $ tº gº & & e g º E tº º sº e º sº e º ſº & & & a tº e º sº tº * c & s & e º is tº # * * * * * * * * Power, heat & light. . . . . . Power & heat. . . . . . . . . . . . Power. . . . . . . . . . . . . . . . . . * * * * * * * * * * * * * * * * * * do . . . . . . . . . . . . do . . . . . . . . . . . . do . . . . . . . . . . . . Uniform... . . . . . . . . do ... . . . . . . . . Variable. . . . . . . . . . . Fairly Uniform. . . . . . . Variable... . . . . . . . . Variable... . . . . . . . . Variable... . . . . . . . . Variable . . . . . . . . . . Variable... . . . . . . . . & B e. e. e. tº * * * * * O Uniform... . . . . . . . . do ... . . . . . . . . 3. : TABLE 4—Detail of data taken on hand-fired plants—Continued. Rating Draft Breeching Average Load. Inches of Water. No. Distance of . Conditions Stack Installation Heavy Light & Under to Size Where No. of Kind Rear Base Which nearest Feet IIleaS- Ells. Furnace of Breech- of taken boiler ured. Hrs. per Coal per Hrs. per | Coal per Boiler ing Stack Ifeet. day day (tons) day day (tons) 1 24 56.0 | . . . . . . . . . . . . . . . . . . . . Natural }}; * * * * * * * * * * * * * * * * * * * * * | * * * * * * * * * * Normal il. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 24 |. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do 0.20 ! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do ||. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.11 3 24 l. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do 0.13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 24 |. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do 0.32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do 6'-0" 4'x5' At Setting |. . . . . . . . . . 5 24 i. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do 0.33 l. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do ". . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.23 6 24 |. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do 0.26 l. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do ||. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.40 7 24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do 0.42 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do ||. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 24 |. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Forced . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do ll. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 4-5 0.9 4-5 | . . . . . . . . . . Natural 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do 8'-0" 5'x0.75' At boiler 2 0.23 Near 10 24 10 |. . . . . . . . . . . . . . . . . . . . do 0.29 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do 12'-0" 3'x4' Stack 1 11 12 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do 0.44 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do 0 l. . . . . . . . . . . . . . . . . . . . . . . . O 12 10 3-4 14 I. . . . . . . . . . do } § is e < a. s. sº ſº e & s is e e s = * * * * * * * * * * * * * * * * do 12'-0" 2’x3' Near boiler 1 13 24 25.0 24 | . . . . . . . . . . do 0.24 . . . . . . . . . . . . . . . . . . . . 0.60 do 10'-0" 6' (Dia.) At Stack O 14 13.5 3.0 l. . . . . . . . . . . . . . . . . . . . do 0.17 | . . . . . . . . . . . . . . . . . . . . 0.42 do ||. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.12 0.14 15 10 8.0 . . . . . . . . . . . . . . . . . . . . do 0.14 0.20 l. . . . . . . . . . . . . . . . . . . . do 20'-0" 3'-2"x2'-6" | At boiler 1. 16 12 |. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do 0.25 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do 0 l. . . . . . . . . . . . . . . . . . . . . . . . O 17 12 |. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do 0.15 |. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do 18'-0" 2'-0"x2'-6" | . . . . . . . . . . . . 2 18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do 9'-0" 2'-6"x2'-0" . . . . . . . . . . . . . 1 19 10 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do 0.30 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do O Stack on boiler O 20 10-24 3.0 l. . . . . . . . . . . . . . . . . . . . Induced | . . . . . g; . . . . . . . . . . . . . . . . . . . . . . . . . . do ||. . . . . . . . . . . . 1'-6" dia. Near Stack 4 0.22 21 10 3.0 . . . . . . . . . . . . . . . . . . . . Natural 0.27 l. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do 10'-0" 3'-0" dia. At Stack O 22 24 2.25 1. . . . . . . . . . . . . . . . . . . . do 0.12 |. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do O Stack on boiler . . . . . . . . . . 23 24 |. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do 0.14 | . . . . . . . . . . . . . . . . . . . . 0.22 do O do do ". . . . . . . * * * * * * * * * * * * * * * * * g g g tº gº tº e g º e s e º e º ºs * & e º g º gº g º ºs * gº º is e º º sº º tº * * * g e º e º 'º s * * * * * * * * * * tº a tº a s & e º & 4 tº º * g º ºs e º 'º º is e º ºs >[oe3S IeeN * * * * * * * g g g tº a IoIIoq Jeanſ * * * * * * * * * * * * IoIIoq 3v. op op * * * * s e º g º ºs s tº * * * * * * * * g e º 'º * * * g is is a e g º 'º sº * * * s e < * g e s a e ,97,IX,97,3 a 0-,9X,0-,7 . .0-9.0…? . a 87,3 ‘eſp ,0-,8 op op • * * * * * * * * * * * is a sº º e º º ºs º ºs & e tº e º ºs e º ºs e º ºs º º * e s º is g º e º & sº de s sº & ſº sº gº º g º e º 'º & e º a $ s e º & º 'º e * * * * * * s p * * * * 49 & tº $ tº $ tº e & © tº q * * * * * * * c & 8 s & sº e s º º e º º & sº º e g º ºs e s s & e º e º ºs e g º = # * g e e º ſº e º e * * * * * * * * > * tº s e s : * * * * * * * * * * * * * sº s * * * * * g g g s e tº e º 'º a g º & e s e Q & e º Aº ‘º e º º s g º e º e s s a ſe 8/."0 Oż'O . . . 88.0 . . . . . . 93.0 . . . . . . . . . . . . . . .97.0 . . . gg-0 |' ' ' ' ' ' ' ' ' ' . . .98.0 . . . . . . . . . . . . . . . . . . . . . . . . .830 . . . gº-0 || ' ' ' ' ' ' ' ' ' Og'I | . . . . . . . . . * * * * is s a e º ºs A8'0 08:0 ' ' ' ' ' ' ' ' ' * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * = & s tº t e º a s s s e º a w s = e e 90.0 : f & s g º 'º e º 'º º e * g º e s & s & º a * @ & E & & P & © & & g g g g g e º ſº a g e g º ſº s > s ºf s * * * * * * * * g e & e º 'º dº e s & 6 a. & e º sº tº º 'º e º s * * * * * * * * * * & e s & s is & © tº e * * * * * * * * * * e a e e s s is e º e a e s tº dº e º s is sº a * * * * * * * * * * * * * * * * * * * * * * tº $ tº º º ºr & * & e º 'º º e s tº tº # is a º e = < * g e * & © gº & # * * * * tº º is & sº tº * * * * e e s e º ºs e e s is * * * * * * * * * * * * * * * : * * * * * * * * * * * * * * * * * * * * * * s & & e e s s e º s * * * * * * * * * * e is sº & sº sº e s is e e = * * * * * * * = & e º e s tº e s is e * * * * * * * * * * * 6 & e º 'º & # * * * * * * * * * * * * * * * * e º is a € $ * & & # * * * * * * * * * * * * * * * * s a s is s º ºs e º e * * * * * * * m & & : º TABLE 4—Detail of data taken on hand-fired plants—Continued. Dampers Stack Smoke Records No. of Total Mins. in one hr. of Aver. Instal- * Area mins. per cent Load lation Kind Usual No. Height Size Square of of during position Feet Feet eet obser- 100 to 80 to Stack Black obser- vation 80 % 60 % Clean Smoke vations. 1 None. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-60'-0" 13.75 2.50 28.75 30.5 2 do . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2-50'-0" 3'-O" 7.1 60 12.25 4.00 25.50 30.6 Normal 4.75 2.25 48.75 11.0 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 40'-0" 2'-6" 4.9 60 16.75 5.00 22.75 38.0 do 4 Automatic. * . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 16.25 5.25 11.50 40.5 do 5 Hand..... . . . Wide open. . . . . . . . . 2 70'-0" 3'-6" 9.6 60 9.50 2.75 25.75 25.0 do 10.75 2.00 40.50 22.0 6 do . . . . . . do . . . . . . . . . 4 70'-0" 3'-6" 9.6 60 11.25 2.00 41.00 22.0 do 5.25 3.75 33.75 19.0 7 Automatic.l.. . . . . . . . . . . . . . . . . . . 6 80'-0" . . . . . . . . . . . . . . . . . . . . . . . . . 60 0.25 .75 40.25 4.8 do 15.25 1.25 34.00 31.0 8 None. . . . . . . . . . . . . . . . . . . . . . . . . . 11 65'-0" 2'-8" 5.9 60 3.25 .50 45.25 9.0 do 9 |. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 40'-0" 2'-8" 5.9 60 16.00 6.50 17.00 37.0 do 10 Hand. . . . . . % open... . . . . . . . . . 1 90'-0" 5'-0" 19.6 60 23.25 4.50 12.25 45.0 do 11 None. . . . . . . . . . . . . . . . . . . . . . . . . . 2 70'-0" 2'-0" 3.1 60 25.25 4.00 17.50 50.0 do 12 Hand. Wide open. . . . . . . . . 1 70'-0" 5'-0" 19.6 60 4.50 1.75 32.00 16.0 do 13 do . . . . . . do . . . . . . . . . 1 145'-0" 6'-0" 28.3 60 28.75 10.50 0.00 65.0 do 14 None. . . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . 2'-6" 4.9 60 4.25 3.75 15.00 24.0 do 15 Hand. . . . . . do . . . . . . . . 1 103'-0" 4'-6" 15.9 60 25.25 10.00 2.50 59.0 do 16 do . . . . . . do . . . . . . . . . 1 72'-0" 3'-0" 7.1 60 0.00 1.50 29.00 11.0 Light 17 None. . . . . . . . . . . . . . . . . . . . . . . . . . 1 50'-0" 4'-0"x4'-0" 16.0 60 0.75 2.25 21.00 15.0 O 18 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 70'-0" 3'-0"x3'-0" 9.0 60 0.00 0.00 52.75 0.3 do 19 Hand. . . . . . . . . . . . . . . . . . . . . . . . . . 1 50'-0" 3'-6" 9.6 60 4.25 1.75 49.25 9.0 do 20 do . . . . . . Wide open. . . . . . . . . 1 20'-0" 1.0" 3.1 60 34.00 6.75 5.75 66.0 do 21 do % to wide open 1 100'-0" 3'-0"x3'-0" 9.0 60 9.75 2.50 29.00 24.0 do 22 do % open... . . . . . . . . . 1 40'-0" 2'-6" 4.9 60 6.50 0.75 47.75 13.0 do 23 do . . . . . . Wide open. . . . . . . . . 2 60'-0" 2'-4" 4.3 60 13.75 3.25 32.50 29.0 do 24 do . . . . . . do . . . . . . . . . 1 60'-0" 2'-6" 4.9 60 5.50 4.50 30.00 20.0 do 25 do . . . . . . do . . . . . . . . . 2. l. . . . . . . . . . . . 2'-6" 4.9 60 2.50 2.25 27.75 12.0 do 26 do . . . . . . do . . . . . . . . . 1 60'-0" 3'-0"x3'-0" 9.0 60 9.50 2.50 34.75 22.0 do 27 do do . . . . . . . . . 1 130'-0" 3'-6" 9.6 60 2.50 6.50 4.00 18.5 do 28 do do . . . . . . . . . 1 135'-0" 2'-6" 4.9 60 2.25 2.00 43.25 10.0 do 89tūņ quºlºgſp ąe sºu ſpe??I op op *{ co o OO ~H CN tº so tº r-ir-i od cici tood tº ºr ‘c’ cocº tº CO rico H r- W-4 F-4 P-4 CN CN rººſ CN r + • • • • • • • • • • • • oS to sºiodoss o, *H CN CŞ cºlo cº tº r" acco co co cooo coooo too coo o * -icº; it usu; H iſ to o, ºf ~ CN r ~ & s s * s P & N. N ŽZZZZZZZZZZZZZZZZZZZZZZZZZZ * / * A ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ zzzzzzzzzzzzz Figure 27–Chain-grate with short ignition arch as applied to Babcock & Wilcox water-tube boiler. as the center of the grate. In this case there is not only loss from incomplete combustion of the gases, loss of un- consumed carbon in the ash, but the grate may be injured by warping, due to the presence of live coal in the ash pit. A chain-grate plant may run very inefficiently if fire is carried only on the front half of the grate, as some- times happens. This, however, allows a wide latitude in 112 THE SM OKE INVESTIGATION operation with the maintenance of a clean stack, especially when the boiler is properly set. The almost universal type of setting of chain grate, as applied to the B. & W. boiler with the usual method of baffling, and as used in the Pittsburgh District is shown in Figure 27. In this type of setting the arch is far too short, thus not providing ample refractory service to maintain the gases at their kindling temperature until combustion is complete. The combustion space is re- 23 2[S. Nº ZZZZZZZZZZZZZZZZZZZZZZZZZZZZ N ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ ZZZZZZZZZZZZZ N N º N N r ZZZZZZZ N Figure 28—Chain-grate with sort ignition arch as applied to Heine water-tube boiler. stricted, and the length of travel of the gases before they strike the cold surfaces of the boiler is much too short. This prevents thorough mixing of the air and gases, and results in incomplete combustion. This type of setting does not readily adapt itself to smokeless operation when boilers are operating at or above rating, and only by means of short fires and high air excess can smoke be eliminated. A chain-grate with short arch, as applied to horizon- tal water tube boiler with horizontal type of baffle is SOME ENGINEERING PHASES 113 illustrated by Figure 28. By encasing the lower row of tubes of the boiler with fire tile, a refractory roof is pro- vided, along which the gases travel, increasing the time allowed for combustion. In this type of setting, the Space provided in the combustion chamber for the mixing of the IFigure 29—Special setting of chain-grate stoker and Babcock & Wilcox water-tube boiler. air and gases is somewhat restricted when compared to best practice. Figure 29 represents a chain-grate stoker as applied to a B. & W. boiler of a special type of setting, and in use at North West Station of the Commonwealth Edison Com- 114 THE SM OKE INVESTIGATION pany, Chicago, Ill. This is known as the Sewall type of setting, and has all the commendable features that lend themselves to smokeless and efficient operation. Figure 30 represents a chain-grate as applied to a B. & W. boiler in which the usual manner of baffling the ſ sh š S s % | - ØØ 2% % N N N ( | || ZZZZZZZZZZZZZZZZZZZZ% it: ś • *.*.*.* *—x-, * * Figure 30—Special setting of chain-grate stoker and Babcock & Wilcox water-tube boiler. gases has been retained. This type of setting is being used by the Commonwealth Edison Company of Chicago, Ill., in part of the equipment of their Quarry Street and North West Stations. In this setting the long coking arch has been retained, the ample combustion space in- SOME ENGINEERING PHASES 115 sures thorough mixture of the air and gases, and the length of travel of the gases is considerably increased over that usually used with the regular type of setting. Figure 31—Chain-grate stoker as applied to Wickes vertical water-tube boiler. Figure 31 shows a chain-grate as applied to a Wickes water tube boiler. Figure 32 shows a chain-grate stoker as applied to a Stirling water tube boiler. 116 THE SMOKE INVESTIGATION ſ º º T- t– . …" Tl TY Figure 32—Chain-grate stoker as applied to Stirling water-tube boiler. • • • • • • • •„6-,8„6-,I48-,„0”, I„ţ-,8„9-,9œ • •• • •Oºg8OpZopop099'9ZopopQZ „0”,940°,48°,487,„9“,„0-,8„0”, A.•0'9993OpZop prºgstre WI]]009“†ZIºu! WD§§§op†Z p „9”,9„0”, †„9“,„9-, I„0”, II„0”,6„0”,6„07,8„0”,9O’I8Zop9-ț¢opop000'6x{OeIS ? 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No. of Instal- Remarks. lation. 1 Good equipment, fairly well installed and operated, general plant conditions poor. 2 Good equipment, properly installed and fairly well operated. General plant conditions poor. 3 Not much care used in operation, surrounding and plant conditions poor. 4 Plant conditions poor and not much care used in operation. Good equipment. 5 Plant conditions and operation good. Good equipment. . 6 Plant conditions and operation good. Good equipment, properly installed. 7 Operating conditions poor, but plant is fairly well operated. Good equipment. 8 Plant conditions and method of operation good. 9 Good equipment, properly installed and well operated. 10 Plant conditions good. Installation properly made and well operated. 11 Good equipment, not properly installed and poorly operated. & iº 12 Good equipment, properly installed and operated. Plant conditions fair. tº e e 13 Automatic damper in stack, hand dampers on boilers 34 open. Good equipment, properly installed, fairly well operated. 14 General plant conditions very good. Good equipment, properly installed and well operated. 15 Plant conditions poor. Good equipment, fairly well operated. 16 Space very much limited, equipment crowded into too limited space, well operated. 17 Good equipment, properly installed and well operated. 18 Working conditions fair, equipment properly installed and well operated. 19 Plant conditions fair. Equipment properly operated. 20 Working conditions fair. Equipment fairly well operated. 21 Equipment properly installed and fairly well operated. 22 General plant conditions fair. Good equipment and very well operated. 23 Boiler room dark and dirty. Equipment properly installed and fairly well operated. º 24 Dark and dirty boiler room, operating conditions poor. Equipment properly installed, fairly well handled. 25 Operating and surroundings conditions poor. Old equipment, fairly well installed and operated. 26 Boiler room very well lighted but dirty. Fairly well operated... 27 Qperating, conditions fair, moderate amount of care used in handling fires. . g 28 General plant conditions good but only moderate amount of care exercised in operation. º 29 Equipment properly installed, only moderate amount of care exercised in handling. Boiler room dark and dirty. 30 Good equipment but only moderate amount of care used in operation. General plant conditions good. 31 Boiler equipment with Wooley furnace. Breeching long and tortuous. § Boiler room dark and dirty. Equipment fairly well installed and operated. General plant conditions poor. Operation fair and equipment in fair condition. SOME ENGINEERING PHASES 127 RESULTS OF SURVEY OF CHAIN-GRATE STOKER PLANTS. Examinations were made of thirty-three plants in which the chain-grate stoker is installed. Pittsburgh coal was used in all of the plants, slack, or nut and slack being used in twenty-three plants and crushed run of mine in ten plants. Horizontal water tube boilers were installed in twenty-three plants and vertical water tube boilers in ten plants. The plants varied in size from 250 to 6,500 boiler horse power, and they contained from one to twenty- six boilers per plant. The thickness of the fire varied from 4 to 8 inches. Natural draft was used in all but one plant, where induced draft was supplied. The draft in the furnace at twenty-five plants varied from 0.12 to 0.40 inches of water; at the rear of the boiler in eight plants from 0.20 to 0.53 inches of water; in the breeching at five plants from 0.38 to 0.80 inches of water; and at the base of the stack in thirteen plants from 0.40 to 0.95 inches of water. Steady loads were carried by eight plants, and variable loads by thirty-three plants. Observations were made upon thirty-six stacks con- nected to boilers equipped with chain-grates with the fol- lowing results: The average of these observations show 2.1 minutes per hour of smoke equal to or greater than 60 per cent. black, 37.6 minutes per hour when no smoke issued from stack and an average percentage of 10.5 black smoke from observations. Observations of this same class show a maximum of 27.0 minutes per hour and a minimum of 0.00 minutes per hour smoke equal to or greater than 60 per cent. black; maximum of 60.0 minutes and minimum of 0.00 minutes per hour clean stack; and a maximum of 51.0 per cent. and a minimum of 0.00 per cent. black smoke from observations. FRONT-FEED STOKERS. There are several types of stokers now on the market employing this principle of feeding coal. They differ mainly in the manner of handling the fuel in the furnace 128 THE SMOKE INVESTIGATION and the method of getting rid of the ash and clinker. The type encountered in most installations, and which prob- ably has been developed to a greater extent than any other, now on the market, is illustrated by Figure 33. In this type the coal is fed from the hopper, placed at the front of the furnace, by means of a pusher plate actuated through an agitator sector, these sectors are in turn operated by eccentrics connected to a shaft and driven through a set of gears by means of an engine or motor. sºrº. A tº Jers Etu-T Cº v AE Wºrt: S £º 㺠% 2 % º fº : % % Nº. % % º à º º & wºSs #*: º sG ps% Jº & gº - º ->§ | ºº s :|Nº. Al R & N tº Rs ov G = F \ ºr tº At Try-A \s, p ou NT Ş% Ş% NSZZZ §ºž% N §4% - sğ% ZZ Ş % --------> Ø º % Žiž», *º Figure 33—Detailed construction of Roney stoker. The stroke of this agitator sector is varied by means of a hand wheel that can be screwed on or off a stud, which is connected to the eccentric strap of the stoker shaft. By varying the position of this hand wheel the stroke of the pusher plate and consequently, the amount of coal fed to the furnace is varied. The coal is fed onto a flat plate called a dead or coking plate, where it is first ignited by the heat from an arch which is sprung over the entire width of the furnace. The length of this arch varies con- SOME ENGINEERING PHASES 129 siderably in different installations. Present tendency is to construct this arch long enough to cover almost the entire furnace, and extend the furnace well beyond the front of the boiler. Air and steam are usually admitted over the fire im- mediately over the dead or coking plate as shown in the illustration. The ignited fuel is pushed from this coking plate by the fresh fuel entering the furnace, onto the cor- rugated set of grate bars placed at the upper part of the furnace. Here it is completely coked, then it is fed onto a second set of grate bars containing more air space per square foot of grate surface. The rocker bar, that moves or rocks the grates, is so designed that the amount of motion it imparts increases from the top to the bottom of the grate. The fuel is practically consumed by the time it reaches the end of these grates, and is now fed onto the dump grate, from which the ash and clinker is droppéd periodically from the furnace. In order that the partly consumed fuel shall not be dumped into the ash pit, a guard is provided which will, when raised, hold this fuel back during the dumping process. In the earlier types of this stoker a single pusher plate, the entire width of the furnace, was provided for feeding the coal. Difficulties were encountered with this type on ac- count of a lack of control that could be exercised in order to keep the grates evenly covered. Changes have been made in the design and now four pusher plates are usu- ally provided with each furnace, the length of stroke of each being separately controlled. This allows consider- able latitude in the control of the fuel bed along the lines just mentioned. The ease of access to the fuel bed, and the ease with which this type of stoker may be made to pick up sudden changes in load has subjected it to considerable abuse in handling. The present tendency to set these stokers with longer arches is much to be commended, the short arch allowing insufficient coking area, and thus permitting green fuel to be moved to the lower grates where its com- bustion is a source of smoke production. Also, when set 130 THE SMOKE INVESTIGATION with a short arch, the distance from the fuel bed to the tubes is much too short, and the combustion space too much restricted to allow either space or time for com- plete combustion of the volatile gases. Care must be ex- ercised in handling this type of stoker in order to keep the fuel bed evenly covered or the coal will avalanche and burn with the production of large quantities of smoke. This is especially true when this stoker is set with a short arch, and a fire carried that is too thin or is allowed to 2. *}}ºz2. 4-422/2ZZZZZZX-E-4%.222 sº s s ~s s s S Ns s šš š º #: % º º º 2&4%2× %22%22%22%22%2. *%: * 'a' 2/2 Ø &: ſº- &zºzºzzº % % ººza Figure 34-Front-feed stoker, Roney model, as applied to Babcock & Wilcox water-tube boiler. burn into holes. Considerable care must be exercised in cleaning the fire, or loss of considerable unburned fuel to the ash pit will result, and large amounts of smoke will be made due to the avalanching of the entire fuel bed. When operated at high ratings, unless provided with some Special type of setting where ample provisions of refrac- tory surface is made, this type usually causes some smoke. SOME ENGINEERING PHASES 131 This, however, may be kept down to some extent by in- creased care in operation. Ø % * º % ſº % % % %% z*z º % % % % z :& % * º % % % # 2Af z * * f Figure 35—Front-feed stoker, Roney model, as applied to Babcock & Wilcox water-tube boiler, Alert type of setting. Figure 34 illustrates this type of stoker, Roney Model, as usually applied to a B. & W. water tube boiler. The 132 THE SM OKE INVESTIGATION distance of the tubes from the fire in this setting is rather short, and the combustion space somewhat restricted to allow proper length of time for mixing the air and vola- tile gases. With the proper care in operation, however, this boiler will operate considerably in excess of rating without the production of black smoke. Figure 35 illustrates this type of stoker, Roney Model, as applied to a B. & W. boiler with Alert type of setting. Provision is made for ample refractory surface and large combustion chambers, both of which are much to be com- Figure 36—Front-feed Stoker, Roney model, as applied to Heine water-tube boiler. mended. This type of setting should develop capacities far in excess of rating, without the production of smoke, if reasonable care is exercised in handling. Figure 36 illustrates this type of stoker, Roney Model, as applied to a Heine water tube boiler having a fire tile roof made by encasing the lower row of tubes in first tile. Provision is also made in this setting to obtain a larger coking area per square foot of grate surface. The fire SOME ENGINEERING PHASES 133 tile roof serves to keep the combustible gases at a high temperature. % N *º%-%º %É \/ N/ º º sN*R l N /N .z’ *º Ž -%.* > % º ſ 42% 2% \ ** * **, 2/* 4.A * *A*. ** * ** * % \ N | | %22% 2% zzzzzze & *A*A**** * 2,222 % * % % * * %2%2%Z N. Z || | \, Z || ||22%2227 72 eae - 22% *A*/º/* */º Aº 2. %22%2% %22%2% *22 ºz. 26/2 *********** */2Ze/º, º ºr A * ,” ea ºz ^2/ZZ, 22.2/. Z/ZZZ %2% *A*, 2* / ? * *. 22.22% 2% **, **** 24.2% A. * sº * *2 ZZ 23.2% ºyz º º, zº 22 ea, ear. X. A 2. % 2 */ºr. * g %22/2 2 ºzºz/ 2. 22 **//a *2. 2 ºz. g * * * * & * % '^, ZZ, Z/2Z. *** * * * *A*, *, A2 ºr 2. A zºº ºr a zºº, , , , , º, øe Figure 37-Front-feed stoker, Roney Model, as applied to a Rust, vertical water-tube boiler. Figure 37 illustrates this type of stoker, Roney Model, as applied to a Rust vertical water tube boiler. This set- ting is characterized by large coking area per square foot 134 THE SM OKE INVESTIGATION of grate surface. The distance from the fire to the tubes, and the size of the combustion chamber is, however, some- what restricted. Figure 38 shows a front-feed stoker, Roney Model, as applied to a horizontal return tubular boiler. Figure 39 shows a front-feed stoker, Roney Model, as applied to a Stirling Boiler. % -s: § & d § º 2. % %ZZZZZZZZZZZZZZZZZZ ZZZZZZº º #WE ę zá % % Figure 38—Front-feed stoker, Roney model, as applied to horizontal return tubular boiler. Figure 40 represents front-feed stokers, Roney Model, as applied to Stirling Boilers at Delray Station of the Detroit Edison Company at Detroit, Michigan. These boilers are equipped with very large combustion chambers which permit of a thorough mixing of the gases and allow ample time for combustion to take place before the gases are cooled below their ignition temperature. Using a high grade, high volatile fuel, remarkable results have been obtained with these units, and little difficulty is encoun- tered in eliminating smoke. - SOME ENGINEERING PHASES 135° №ĒĒĒĒĒĒ， № Eſ & Ż 3. 7 & (D as Ņ §§ ÑŅŇ N N N§ ````§ § Ø--Rºzºg *~ Ż § à NL –¿<<）{<（$ N § \\ | （ )N N≡≡≡E [−）|--------p=0 -E TI „NIL F|||NO N zºzzz!（ ● �§§ Ø % \ || ||D applied to Stirling water-tube boiler. Figure 39—Front-feed stoker, Roney model, as 136 THE SMOKE INVESTIGATION w t : ! ; : ; : B– +-GB- ; : - A t t -Yº" t - | - a tº Azazar Figure 40—Front-feed stoker, Roney model, as applied to large Stirling water-tube boilers. : TABLE 6—Detail of data taken on plants equipped with front-feed stokers. Coal Stoker Furnace. No Dimensions Feet and inches. of Grate º; Commercial - Quantity Kind of Thickness Frequency Grate to H. S. Front Height - ation | Name Size per yr. Stoker of Fire of No. Area Furnace Coking arch Length Height Tons Inches | Cleaning Width Length to Coking Arch Sq. Ft Front Arch | Rear Aver. Min. Boiler Front l Back Furnace 110,000 8–78 tº ſº tº 1 Pittsburgh §. d 180,000 ||Roney 4-7 2 in 5 hrs 22 || 14-56 9'-0" . . . . . . . . . . . . . . . a s - a w w w w s I & s - e s - s - tº º 1'-0" 5'-0" . . . . . . . . . . 4'-0 TUISE16. 2 (a) do Run of Mine Old Model Roney 4-6 6 '' 24 '' 2 93.6 a • a s s a e s a e º is a 1'-0" 8'-8" 0 l. . . . . . . . . . . . . . . . . (b) do do 91,000 do 4-6 6 '' 24 '' 6 86.0 * * * * * * * * * * * ~ * - 12'-6" 7-2" 0 l. ... . . . . . . . . . . . . . . . . . . . . . . (c) do do Total do 4-6 || 6 '’ 24 '' 5 68.2 • * * * * * r * - - - - - - 9'-0" '-8" |..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (d) do do for all do 4-6 || 6 '' 24 '' 3 62.0 * - e = - & 1 - - - - - - - 9'-0" 7'-2' . . . . . . . . . . . . . . . . . . . . . . . . . . (e) do do plants do 4-6 || 6 '' 24 '' 2 62.0 * * * * 9'-0" '-2" |..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do do do 4-6 6 '' 24 '' 1 53.0 * * * * * * * : * * * * ~ * * 7'-9" 77-2" 3 do do i. . . . . . . . Roney 3–24 2–4 '' 24 '' 4. 87.8 8'-0" . . . . . . . . 9'-6" '-3" O 4 (a) do Slack | . . . . . . . . do 6–8 . . . . . . . . . . . . 2 45.5 8'-6" 7'-6" 7'-0" '-6" 0 l. ... . . . . . . . . . . . . . . . . . . . . . (b) do do [.. . . . . . . . do 6-8 I. . . . . . . . . . . . 4 || 45.5 8'-6" 7'-6" | 7'-0" 6'-6" 0 l. ... . . . . . . . . . . . . . . . . . . . . . . . . . . . (c) do do Í. . . . . . . . do 6-8 |. . . . . . . . . . . . 3 || 47.7 8’-6* 7'-6" | 6’—10" 7'-0" 0 l. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (d) do do . . . . . . . . do 6-8 l. . . . . . . . . . . . 4. 52.5 8'-6" 7'-6" 7'-0" 7'-6" 0 l. . . . . . . . . . . . . . . . . . . . . - e º 'º s - ſº - (e) do do . . . . . . . . do 6-8 l. . . . . . . . . . . . 2 53.6 8’-6” 7'-6" 7'-8" 7'-0" O * ' ' ' ' '..., A', ‘ I 2., As '1' '4', 3 ; 5 do do 7,500 do 4-5 2 ” 24 '' 8 68.0 7'-6" 5'-6" 10'-0" 7'-0" 8'-8" 1'-3 3-9. 3-9. 5-3. 6 do do . . . . . . . . Brightman 6 6 '' 24 '' 4 § 7'-6" 5'-6" % º %3. O 2'-6" 6'- 6'-6 4'-0 3 - *_ º *_ º 7 do do 68,000 ||Roney 5 4 '' 12 ” 5 59.4 e - e s tº e a º ºr e - & wº 77-9" 7'-8" 0 1'-8" 2. 9. 4-8. 8 do do do 8 6 '' 24 '' 5 || 49.0 18'-0" . . . . . . . 7'-4" 6'-8" 4'-0" r 3-3. 3. 3. 9 do do 10,000 do 4-5 2 ” 24 '’ 6 || 50.0 • * * * * * 1 s e º e º º 4 8'-4" '-0" 6) 1:9" '-3. 3. p 10 do do 3,000 ||New Model Roney 4-6 || 6 '' 24 '' 2 34.8 5'-0" 4'-0" | 6'-3" 5'-6" O 10. 3-9. '-9. 11 do do 3,100 ||Old do do 4 2-5 '' 24 '' 3 49.0 * * * * * * : * * * * - * * 7'-0" 7'-0" r 1-2. 3. p 2. 4. 12 do do 11,200 Roney 4. 3 '' 24 '' 3 60.4 14'-0" | 12'-0" 8'-4" 7'-8" 1'-6 1.Q. 3-2. 4- tº 13 do do 2,400 do 3 5 ° 24 '' 3 30.0 6'-6" 4'-6" 4'-0" 7'-6" 3'-0" 1 ty 4-9. 3-9. • * * * * * * * 14 do Nut & Slack 23,000 || do 4 || 4 ° 24 " || 5 | 66.7 12'-0" | 10'-0" | 8'-4" | 8'-0" O 10. lºš. ºff. - 'gº. . 15 do Nut 4,300 do 4 6 '' 24 '' 2 #% 7'-6" 6'-6" | 6’–0" '-0" 6%" 1’–6 2'-6 2'- 6'-0 16 do 1% Slack |. . . . . . . . do 4–5 || 4 ° 24 '' 13 |100-130 |..... . . . . . . . . . . . . . . . . . . . . • , , , , , , , , , , , , , , , , º, e - || < * * * * * * * * | * * * * * * * * | * * * * * * * * * | * * * * * * „0”, I „0”, I „9”, I | || || || || .4078. „Qyſ || .407,9 „Q?? || .407,9,... . „0”, ZI„0”,ïſºſ „9“, †„0”,9 40T,„9-,9 - → • • • • •„0”,9 *H ºf to dº ºf ºf to CN O y-l 0I sºție.A ● ●†Z , , †73 & &#Z , , †73 & &#Z ، ،†Z , , †Z & &ÞZ , , † 3 & &†Z ، ،†Z £ €†Z & &ÞZ … Þ3 & &#Z Œ œ†Z , , †Z ,, †Z ، ،†Z … 9 … 9 … 9 … 9 … 9 … 9 … 9 , , † . , † , , † , , † , , † . , † … ? ... 9 , , † ... 9 ‘a e9 … 8 * “Poº Aſºo Aſº KO Ne F ºr tº troº *H ºf{ *H uſ) Aſº Aſº SC J. 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IºdáLuoņeſ 3InSS31&I”ONIsuºpIȚngſ-Ț84su I ta834SJO Áureo oſ pºsn ‘onſ*ON peo“ISIÐIſoſſ ºpºnuņuoO—saagoſs paø4-4u044 iſſum podſłºnbº słupſq uo uøąd, og op go typ;act—93'IavJ, 140 • • • • • •œ• •op • ©��«», «op • • •�• •op • • • • • • • • • •• •op • • • • • • • • • •• •op •• • • • • • • • • •op • • • • • • •·ºſqëſue A • • • • • • • • • • • •op • • • • • • • • • • •op a ， «» ，• • ••op • • •ș• ，op w o• •«• •op • • • • • • • • • • • • »op • • • • • • • • • • • • •3[qeſue.A • • • •*** IIIIogpunAſuſeſ - - - - - - … • • •€ œ •op • • • • • • • • • • • •op • • • • • • • • • • • •tūJoyſun • • • • • • • • • • •º[qeſue A OZI-OIT OZI-OIT 0ZI gº I-OZI 9ŻI-OZI 92.I-OZI • • • • • • • • • CN ch ºf Aſ) to do º Aſº Ob (NGO • • • • • • • • • •op”AA 28 *{I • • • • • • • • • •op”AA 29 °{I «• • • • • • • • • •op”AA 28 °8I • • • • • • • • • •op*AA 28 *{I • • • • • •op3ūļļiņS • • • • • • • • • •op3ūſiņS • • • • • ••opÁ3țO 3ļī£I • • • • • • • • • •opĮTeqe) • • • • • • • • • •op”AA ? "8I • • • • • • • • • •opIoĻKeJ,uel IIȚpny • • • • • • • • • •op uoſ Ke L uel IIȚInv 23 "AA ? "8I • • • • • • • • •opJoĻĀe Lºueurųny† “AA ? "8[ ZT • • • • •• • • • • •oploſ Ke Lºu etaļpny • • • • • • • • • •op”AA 28 *{I • • • • • • • • • •Op ’A 23 °{I Z IoſÁæI, ºu etaļpny z • • • • • • •• • •opKąțO3ȚIĞI • • • • • • • • • •op”AA 28 *{I • • • • • • • • • •opAA 29 °{{ • • • • • • • • • •op”AA 28 °{I 141 º TABLE 6–Detail of data taken on plants equipped with front-feed stokers—Continued. Rating Draft Breeching Average Load. Inches of Water. Nº. Distance ti, - Conditions. Stack Ins tion Heavy Light e Under to Size Where No. of Rind Rear Breech- Base Which nearest Feet IIlea S- Ells. Furnace of ing of taken boiler ured. Hrs. per | Coal per | Hrs. per | Coal per Boiler Stack Feet. day day (tons) day day (tons) 1 2-7 l. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Natural 0.3-0.5 ! . . . . . . . . . . . . . . . . . . . . 1.00 (. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2 (a) 24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do 0.2-0.3 |. . . . . . . . . . 0.90 0.90 | . . . . . . . . . . 10'-0" 4'-6"x6'-6" At Stack I } 24 |. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4'-0"x6'-0" . . . . . . . . . . . . 1 6) I. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . § • e s tº e s tº e º - I - e - e. e. e. e s e º I e - e. e. a e s e e s : * * * * * * * * * * do I. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . e) |. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do I. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . * * * * * * * * * * * I • * * * * * * * * * (f) |. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do I. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.15 0.40 3'-6" x5'-0" to 2–90° 3 24 |. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do § 0.50 | . . . . . . . . . . 1.00 !. . . . . . . . . . 21'-0" 10'-0"x5'-6" | Each end 1–45° 4 (a) 24 |. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do 0.23 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.18 (b) 24 |. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do 0.26 ſ. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.12 (c) 24 |. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do 0.22 (. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.11 (d) 24 |. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do 0.15 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (e) 24 |. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . * * * * * * * * * 5 24 |. . . . . . . . . . 24 1. . . . . . . . . . do 0.48 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8'-6" 15.5 sq. ft. . . . . . . . . . . . . O 6 24 |. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do 0.15 • * * * * * * * * - I • - - - - - - - - - - - - - - - - - - - -., - - - - - - - - - - II • * * * * * * * * * * * 10'-3"x1'-6" . . . . . . . . . . . . O 0.08 7 24 |. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do 0.20 |. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15'-0" 4'-0" dia. I. . . . . . . . . . . . . . . . . . . . . . 0.15 - 8 12 l. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do 0.45 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Normal ||. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 0.20 Between 9 12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do 0.30 l. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15'-0" 5'-6" x 9’–8” 1 & 2 stack 1. 10 12 30-35 | . . . . . . . . . . . . . . . . . . . . do 0.20 (. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 11 24 9.0 l. . . . . . . . . . . . . . . . . . . . do 0.25 1. . . . . . . . . . . . . . . . . . . . 0.75 |. . . . . . . . . . 12'-0" *::::::" Near stack 2 - –0" dia - 12 12 21.0 12 10 do 0.20 ! . . . . . . . . . . . . . . . . . . . . 1.00 l. . . . . . . . . . 89'-0" 6'-0" do | . . . . . . . . . . . . 3. 13 10 l. . . . . . . . . . 14 25 do . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18'-0" 3'-0"x3'-6" | . . . . . . . . . . . . 2–45 £ 29 I· · · · · · · · · · · · į „9-,£x,0-,8suºſſoq ||· · · · · · · · · · g ? I ' [' + · · · · · · · · · ·„9-,8X40-,8SI3Iſoq || • • • • •• • • • •Oý“I (2) (q) (0) ºg c oq Ç) lº) ! - O O "U c Mſ) (NO • • • • • • • • • • 8· · · · · · · · · · · ·| „9-,8x,0-,8„0”,08• • • • • • • • • •， ， 9• • • • • • • • • • • •„9-,8×,0~,8.0-01 || ' ° ' '• • • • • : - «» – sº ch :* hº CŞ C O wd I* * * * * * * * * * * * | „9-,8x,0-,8op-999::: I• • • • • • • • • • • •„9“,8X„0-,8op• • • • • • • • • -0/'0• • +-) ToeņS JeoN | „0-,9x,0-,g„0-,02 || * * * * * * * * * *g#’O ſº · · · · · ·• • • • • • • • • • • • • •80’0opgI-OIÞZ08-93 3 † - I. · · · · · · ·• • • • • • • • • • • • • • •* * | „O-,9 || ' * * * * * * * * *g/, '0 |* * * * * ** * * * | 9ŤO6Z°0op ||· · · · · · · · · ·6I ， · · · · · · · · · gI’O0I°0• -● 0>[OeļS I 83 NI | „O-,9x,O-,Ť | „0”,9 I || ‘ ’ “ ’ ”: : : : :|: : : : : : : : : :|: : : : : : : : : :| , , 88:0 | | | | | 03:Q , . || QP || ... ?? . . . .| 9ſQĄ. o ſº · · · · · · ·· · · · 1 ,0-,9x,0-, 2 || .0-,zI ||· · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·]* * · · · · · · · · I · · · · · · · ·op#I0^9 , Gº Gº O O C C C 3 NX, SSNN. S.S. N. S. SX, SSN. S. 3 & 3 R- § Gºd OO Aſº * - ~}{ \o wº- yº 143 TABLE 6—Detail of data taken on plants equipped with front-feed stokers—Continued. * Dampers Stack Smoke Records No. it. Total Mins. in one hr. of Aver. j *- & Area mins. per cent Load ation Kind Usual No. Height Size U13ſe of of during position Feet Feet eet obser- 100 to 80 to Stack Black obser- vation 80 % 60 % Clean Smoke vations. e 6.75 1.25 47.50 12.6 I Hand. . . . . . Wide open. . . . . . . . . 7 150'-0" 7'-0" 38.4 60 14.75 12.00 4.25 43.3 |. . . . . . . . . . . . . . 13.25 8.50 24.50 31.6 2 } do ... . . . do . . . . . . . . . 1 150'-0" 5'-9" 26.0 60 18.00 14.00 9.00 47.3 1. . . . . . . . . . . . . . b) do ... . . . do . . . . . . . . . 3 125'-0" 5'-3" 21.6 60 0.25 5.50 45.75 10.0 l. . . . . . . . . . . . . . * 125'-0" 4'-9" 17.7 (c) do . . . . . . do . . . . . . . . . 2 125'-0" 5'-9" 26.0 60 5.50 3.35 17.50 25.0 l. . . . . . . . . . . . . . - 125'- º 4'-9" 17 7 (d) do ... . . . do . . . . . . . . . 2 125'-0" 3'-6" 9.6 60 23,00 8,75 6.50 54.0 l. . . . . . . . . . . . . . % do . . . . . . do . . . . . . . . . l 125'-0" 4'-6" 15.9 60 0.00 0.00 24.75 12.0 . . . . . . . . . . . . . . do . . . . . . do . . . . . . . . . On stack (d) • * * * * * * * * * * * * * * * * * * * * * * * * | * * * * * * * * * * * * * * * * * * * * * * * | * * * * * * * * * * * * : * * * * * * * * * * * * | * * * * * * * * * * | * * * * * * * * * * * * * * 3 None. . . . . . . . . . ... . . . . . . . . . . . . . . . 1 165'-0" 11'-0" 95.0 60 8.25 19.00 9.25 42.5 l. . . . . . . . . . . . . . 4 (a) Hand. . . . . . Wide open. . . . . . . . . 1 127'-0" 5'-0" 19.6 60 2.00 3.00 37.00 13.5 . . . . . . . . . . . . . . 5.75 3.00 37.25 17.5 (b) do . . . . . . do . . . . . . . . . 2 132'-0" 5'-0" 19.6 60 19.75 16.75 2.00 53.0 l. . . . . . . . . . . . . . c) do ... . . . do . . . . . . . . . 3 82'-6" 3’-10° 11.5 60 0.00 1.00 18.25 16.0 l. . . . . . . . . . . . . . d) do . . . . . . do . . . . . . . . . 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 2.75 0.75 49.25 6.0 . . . . . . . . . . . . . . e) do . . . . . . do ... . . . . . . . 2 116'-0" 4'-6" 15.9 60 2.75 0.75 49.25 6.0 l. . . . . . . . . . . . . . sº 0.50 0.25 54.00 3.0 5 Automatic [.. . . . . . . . . . . . . . . . . . . . 8 120'-0" 4'-0" 12.6 60 0.25 1.00 53.75 3.3 Light 6.00 4.50 31.25 20.0 6 Automatic 1. . . . . . . . . . . . . . . . . . . . 4 125'-0" . . . . . . . . . . . . . . . . . . . . . . . . 60 7.75 4.00 33.25 22.0 Very Light 88'-0" '-4" 8.7 7.25 9.25 12.25 34.0 7 Hand. . . . . . Wide open. . . . . . . . . 2 80'-0" '-0" 7.0 60 3.00 0.75 34.75 16.0 l. . . . . . . . . . . . . . - 0.25 0.75 50.00 4.0 8 do . . . . . . do . . . . . . . . . 2 135'-0" 6'-3" 30.7 60 0.00 1.25 0.00 27.0 |. . . . . : - - - - - - - - 19.60 17.00 15.25 44.0 Readings at 9 Automatic l. . . . . . . . . . . . . . . . . . . . 1 150'-0" 5'-0" 19.6 60 15.40 3.75 13.50 38.0 different times 10 and. . . . . . Wide open. . . . . . . . . 1 70'-0" 4'-0" 12.6 60 0.50 0.00 52.50 3.0 l. . . . . . . . . . . . . . 11 do . . . . . . O . . . . . . . . . 1 168'-0" 5'-6" 23.7 60 14.00 3.00 14.75 36.0 l. . . . . . . . . . . . . . 12 do . . . . . . do . . . . . . . . . l 175'-0" 5'-0" 19.6 60 7.00 17.25 11.50 49.0 l. . . . . . . . . . . . . . 13 Automatic 1. . . . . . . . . . . . . . . . . . . . 1 160'-0" l. . . . . . . . . . . . . . . . . . . . . . . . 60 0.00 0.25 57.50 1.1 . . . . . . . . . . . . . . 14 d. . . . . . % open... . . . . . . . . . 1 385'-0" 7'-0" 38.5 60 0.25 2.50 44.65 8.8 . . . . . . . . . . . . . . 15 do . . . . . . Wide open. . . . . . . . . l 167'-0" 4'-3" 14 60 20.75 9.50 14.00 44.1 ! . . . . . . . . . . . . . . : 33 (a) (b) (c) 34 do . . . . . . Automatic do do * * * * * * * * * * * * * * * * * * * & II, do . . . . . . . . . s e & e º s º & 6 s is º & & w s ºr e s is do tº e º ºs e º 'º e º gº tº gº & ſº gº tº e s $ $ * * * * * * * g is e s tº it is tº º is s = s * * * e g = e º ſº gº is gº tº ºi e º ſº sº º is 1 6-125'-0" 1-150'-0" 135'-0" * * * * * * * * * * * g. 7'- ty } 8 ; i 2 4 # : ſº : | & º & & & © # & G & gº s gº º * * * * * * * * * g º º & a # * * * * * * * * * * * * * tº $ $ tº ſº tº $ is tº gº tº º a tº # TABLE 6—Detail of data taken on plants equipped with front-feed stokers—Continued. No. of Instal- Remarks. lation. 1 Old equipment, undergoing extensive repairs. Not much care used in handling fires. Surrrounding conditions fair. 2 § Good equipment, some parts properly installed, not much care exercised in firing. Working conditions poor and boiler room dark. (c) (d) (e) (f) * Good equipment but not installed so that it lends itself to smokeless operation without the exercise of considerable care. 4 § Equipment and manner of installation, in this plant, varies from fair to ordinary. Operating conditions and method of handling vary in same proportions. (c) § € 5 Operating conditions and equipment good. Boilers operated far below rating. 6 Good equipment but poorly installed and operated. Operating conditions poor and firing poorly done. 7 Old equipment, poorly installed and operated. Operating conditions poor. 8 New equipment, properly installed and operated. 9 Old equipment, undergoing extensive repairs and renewals. Surrounding and operating conditions good. 10 Good equipment, properly installed and operated. General operating conditions good. 11 Equipment in poor condition, not properly installed or operated. General plant conditions poor. 12 Good equipment set in somewhat restricted space, general conditions good, firing fairly well done. 13 New equipment, proper installed and fairly well operated. General plant conditions good. 14 Good equipment, considerable care exercised in operation. 15 Good equipment, fairly well installed and operated. General plant conditions fair. 16 Old equipment, poorly installed and not much care used in operation. General plant conditions not very good. 17 Good equipment, properly installed and operated. General plant conditions very good. 18 Good equipment, fairly well installed and operated. General plant conditions very good. 19 Equipment poorly installed, not in very good condition and very little care used in operation. General plant conditions good 20 Not much care exercised in operation or installation of this equipment, general plant conditions good. 21 Equipment in fair condition, not much care exercised in operation considerable poking through small doors. e g 22 Arch very short, considerable poking through small doors in front. General plant conditions good, not much care used in firing. 23 Boilers probably operating far below rating, set with short arches and restricted combustion space, not much care used in firing. 24 Boilers not required to deliver power much in excess of rating. General plant conditions poor, very little care used in firing. 25 General plant conditions good, boilers not properly set and very little care exercised in operation. g 26 Dark and dirty plant conditions, boilers not properly set or operated, developing powers not in excess of rating. 27 Operating conditions poor, not much care used, in firing considerable poking through small poke doors. 28 Boilers not properly set, not much care exercised in operation, general plant conditions poor. § Equipment properly installed and surrounding conditions good but not much care exercised in operation. Analysis of flue gas showed CO2-5.2% 0-14.6 N-80.2. Probable boiler efficiency 50%. Good equipment fairly well installed and operated, general plant conditions fair. Good equipment, installation somewhat hampered by restricted space, neccessitating small combustion chambers. Considerable poking thru small doors at front of strokers. Good equipment but requires exercise of excessive care to operate smokelessly. 148 THE SM OKE INVESTIGATION RESULTS OF SURVEY OF FRONT-FEED STOKER PLANTS. Examinations were made of thirty-four plants in which the front-feed avalanche type of stoker was installed. Pittsburgh coal was used in all of the plants. Slack, nut and slack or run of mine and slack was used in twenty-One plants; and crushed run of mine or nut size was used in thirteen plants. Water tube boilers were installed in all of the plants examined, the majority of these being of the horizontal type. The plants varied in size from 450 to 7,980 boiler horse power per plant, and contained from 2 to 22 boilers per plant. The thickness of the fire carried varied from 3 to 24 inches. The draft in the furnace at thirty plants varied from 0.08 to 0.48 inches of water, in the breeching at twelve plants from 0.15 to 1.30 inches of water, at the base of the stack at twelve plants from 0.43 to 1.40 inches of water. Steady loads were carried by eight plants and variable loads by twenty-six plants. Observations were made upon sixty stacks connected to boilers under which this type of stoker was installed with the following results as regards smoke production: The average of the observations show 14.6 minutes per hour of smoke equal to or denser than 60 per cent. black, 22.8 minutes per hour when no smoke was omitted from the stacks and an average of 27.2 per cent. black Smoke. Observations on this same class show a maximum of 57.50 and a minimum of 0.00 minutes per hour of smoke equal to or denser than 60 per cent. black. A maximum of 57 and a minimum of 0.00 minutes per hour in which no smoke was emitted from stacks; and a maximum of 63 per cent. and a minimum of 1.1 per cent. black smoke. SIDE-FEED STOKERS. Stokers employing this principle in feeding the fuel have not been subject to as many variations in design as those using the front feed principle, although they have been on the market in this country for many years. The main difference in the construction of the various types of this stoker, as now on the market, is in the method of SOME ENGINEERING PHASES 149 feeding the coal and getting rid of the ash and clinker. In this type, at either side of the furnace, and extending its entire length, is a coal magazine, at the bottom of which is the coking plate which supports the upper end of the inclined grates. A coking arch is sprung over the entire furnace, and usually extends well beyond the end of the furnace. This arch is supported on side plates, which form part of the magazine in which the coal is con- Figure 41—Vertical cross section of side-feed stoker, Murphy model. tained. Between the sides of the arch and these side plates there are a series of openings, through which air is admitted over the fire after it has passed over the outside of the main arch and been heated. An auxiliary arch is usually sprung over the main arch, and an air space is left between the two. The coking plate is cooled by pass- ing air beneath it to the back of the furnace from whence it passes to the air space between the arches and is there admitted over the fire. 150 THE SM OKE INVESTIGATION Coal is fed from the magazine, as illustrated in Figure 41, by stoker boxes which move back and forth on the coking plate and push the coal through the throat opening and discharge it on the grates. The stoker boxes move back and forth a fixed amount and are operated by a small segmental gear keyed to the stoker shaft, and this is, in turn, driven by the engine or motor provided for this purpose, and also to impart motion to the grates. The amount of coal fed to the furnace in this type is controlled entirely by the speed of the driving engine or motor. The coal when pushed into the furnace is ignited by the heat of the arch. The volatile products are distilled off in the presence of the heated air supply through the ducts at the side of the arch. The ignited fuel is pushed by these stoker boxes and the fresh fuel enfering the fur- nace onto the grate bars, where it is completely coked and carried through the various stages of combustion, finally to be dumped out at the bottom in the form of ash and clinker. The grate bars in this type of stoker slope from the sides toward the center, where a device is placed for grinding up the clinker and dumping it into the ash pit. The grate bars extend from the coking plate to the clinker breaker, alternate bars being movable at their lower ends both above and below the surface of the stationary bars, the upper ends being pivoted at the coking plate. The clinker bars in the two types of breakers differ radically. In one of the types of clinker breaker, a hollow iron bar with projections on its surface and running the entire length of the furnace is used. This bar is rotated and grinds up the clinker. A second type of clinker breaker has heavy iron disks with projections on their surface placed at the bottom of the V formed by the grate bars and actuated by a reciprocating bar connected to the driving engine. With this type of stoker a large amount of coking space per square foot of grate surface is always provided, and they are usually set with ample combustion space. The main difficulty that has been encountered is in keep- ing the grates evenly covered. This has been overcome, however, to some extent by changing the stroke of the SOME ENGINEERING PHASES 151 stoker boxes 89 that the fuel will be fed to the fur- nace in such * manner that * even fire will be main- tained. The device for the handling of the clinker does not take care of the clinker at all times. It is especially true that the clinker must be removed through the firing door, by hand with a hook, when the fires are forced hard. This operation usually results in the production of smoke, - - - - -- *- - - - - - - * * * * * * * * * - - - - - - - - . . . . - - - - - * * Figure 42—Side-feed stoker, Murphy model, as applied to Heine water-tube boiler, flush-front setting. as the fires are usually burned short to allow the clinker to rot so it can be removed. When the clinker is removed, large quantities of green fuel are fed to the furnace by hand manipulation of the stoker boxº and the fire is liberally hooked until it is in good condition. This opera- tion usually results in producing smoke. Due to the ease of access to the fire, this type of stoker is subject to con- siderable abuse in firing by hooking the fire through the 152 THE SM OKE INVESTIGATION front door. This tends to cause a very intense fire, and, if the grates are kept well covered, will not cause exces- sive smoke, due mainly to the provision of ample refrac- tory surfaces and liberal over-fire air supply. When al- lowed to operate with short overhanging fires which are well burned out at the bottom of the grate, the use of the hook to stir up the fire is usually productive of much smoke. These stokers are usually set with the Dutch oven or a modification thereof. The usual Dutch oven setting Figure 43—Side-feed stoker, Murphy model, as applied to Heine water-tube boilers, extended oven setting. is known as the extended-front, and the modification thereof as the flush-front setting. Figure 42 illustrates a stoker of this type, Murphy Model, as applied to a Heine water tube boiler with flush front setting. This setting should only be used where space available is very much restricted, in that it has the disadvantage that all the coal fired usually is charged to the magazine by hand. This usually results in the back portion of the grate being uncovered due to a lack of coal at this part of the magazine. Furthermore, it has the dis- SOME ENGINEERING PHASES 153 advantage of exposing a part of the heating surface of the boiler, only to heat radiated from the arch. Figure 43 represents an extended-front setting of a Murphy Stoker as applied to a Heine water tube boiler. This setting has the advantages of the fire tile roof in the combustion chamber. Figure 44 shows an extended front setting of a Murphy Stoker as applied to a B. & W. water tube boiler. SN [...] * Slſ > *sº s sºft s S. & s Sº s S : HEEE T-EEE TEL; H-E-T- Figure 44–Side-feed stoker, Murphy model, as applied to Babcock & Wilcox water-turbe boiler, extended oven setting. The distance from the grates to the exposed tube surface is somewhat restricted in this setting, and should be remedied by setting the boiler higher. Figure 45 illustrates an extended front setting of a Murphy Stoker as applied to a return tubular boiler. Figure 46 shows an extended front setting of a Murphy Stoker as applied to a Stirling water tube boiler. 154 THE SMOKE INVESTIGATION < P 43. He– ! i | | t t r t l i t §----— ſ º: = } ºff: ; * K. - Hºº-ºº: º º J º º D D D. " t | D. : L [in it # N * R tº wº- L EE ; | Nº. *º-º-º-ººººººººººººººººººººººººººººººrººs #22:22 L N - a zºº Zºr-Eº-E - | }º: º º º tº: ... " t |WII) :::: #: tº tº sº tº E- 4:2:2:: SS Šº 2T # Yºğºl; # ; § ū; tº º [[III]. E wº §: \\ . º ——º- º Slalºa & % ºz. % 4: - . - * T; Figure 45–Side-feed stoker, Murphy model, as applied to horizontal return tumular boiler, extended front setting. Figure 46-Side-feed stoker, Murphy model, as applied to Stirling Water-tube boiler. : TABLE 7—Detail of data taken on plants equipped with side-feed stokers. Coal Stoker Furnace. Dimensions Feet and inches. No. of Quantity Thickness Frequency Grate Instal- Commercial per yr. Kind of of Fire of . No. Grate to H. S. Front Height lation Name Size Tons Stoker Inches Cleaning Area Furnace Coking arch Length |Height Width Length to - Coking Arch Sq. Ft. Front Arch | Rear Aver Min Boiler | Front Back Furnace - Slack 13,000 ||Murph 4-5 2 in 24 hrs. 3 50.0 9'-0" 5'-6" 5’-10" 6'-8" 8'-0" | 6’—4'-0" | 6’—4'-0" 8'-8" 4'-4" ; Pittºrgh do 6,000 urºy 4-6 Continuously || 4 36.0 '-0" 3'-0" 4'-6" 6'-0" '-0" | 6'-3'-0" | 6'-3'-0"| 8'-0" '-0" 3 do do 10,000 do 5 do 6 60.0 s & e º sº I e s º º ſº * * 6'-0" "-0." § 3. 6”-4'-3" | 6’—4'-3"| 9'-0" . . . . . . . . d 7,700 do 6 do 3 80.5 10'-0" 6'-0" 7'-3" | 7-10" 13'-0" | 12"-6'-0"|12"–6'-0"| 7'-0" : 3. . 15,000 do 6 do 5 115.0 9'-0" 7'-6" | 10'-0" '-0" ... . . . . . 12"-6'-6"|12"-6'-6"| 9'-0" 6 do Nut & Slack 1,250 do 2%-12 do 2 55.0 '-0" 6'-0" 5'-9" 6'-8" '-0" | 6"-2'-8" | 6"-2'-8" 7'-6" 7 do Slack 3,100 do 4–5 || 8 in 24 hrs 4 40.0 10'-0" 6'-0" '-0" 6'-0" 7-7" | 6’-3’-10'6'-3'-10" 6'-0" 8 do Run of Mine 775 do 3–4 || 2 ” 24 '' 2 30.0 '-7" | . . . . . . . 4'-0" 6'-4" 7'-4" | 6'-2'-6" | 6’–2 '-3: 7'-6" 9 do Slack 11,000 do 5-7 || 2 ” 24 '' 5 41.0 * * * * * '-0" 4'-8" '-0" O 6"-4'-0" | 6’—4'-0"| 8'-0" 10 do do ,000 do 6 2 ” 24 '’ 2 60.0 6'-0" 3'-0" 7'-0" 6'-0" 7'-0" | 6'-3'-6" | 6'-3'-6"| 6'-0" 11 Youghiog- - f * A º p p f ſº t 1,320 do 6 |Continuously || 1 33.0 • * * * * * * * * | * * * * * * * 6'-0 5'-6 2'-9 : ; ; ; A's A y' . . As 5'-6 12 Pºrº, ãºut & Slack 130,000 do 4-8 Varies 40 | 96.5 3-3 || 2:3. 3-9. º: 7.9 |3:4-9. 3-4-2: 1–2. 13 (a) do 34” do 18,250 do 4-8 || 2 in 24 hr 8 60.0 8’–0 4. -9. 5 -9. 7-9. 7 |-}}. 3-3-3. 3-3-3. 7-9. (b) do do 18,250 do 4-8 2 ” 24 '' 8 60.0 10'-0" 5'- 5'-0 –0 7'-11 6'-3'- 6'-3'-6" 7-0 14 (a) do 2* do 1. . . . . . . . do 5-7 || 3 '' 24 '' 4 95.7 18'-0" | 15'-0" 5'-6" '-0" 8’-10* || 6’—4'-0" | 6’—4'-0" '-0" b) do do I. . . . . . . . do 5-7 || 3 '' 24 '' 4 80.5 16'-0" | 14'-0" 5'-2" '-0" . . . . . . . 6*-4'-0" 6*-4'-0" 7'-0" % do do I. . . . . . . . do 5-7 3 2 x # x 2 ; #: '-0" 5'-0" 5'-0" '-0" 7–11” 6"-4'-0" *-4'- * 7'-0" do . . . . . . . . do 5-7 || 3 '' y y - e e º & • * * * * | * * * * * * * * | * * * * * • * * - a - - * * * * * * * * * * * g e º tº s a • * * * } | . . . . . . . . . . do 5-7 | 3 '' 24 " || 2 | 73.5 !..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . * * * * * * * * * * g. s is & tº e tº e º a º e º 'º º * * * * * * * * : TABLE 7—Detail of data taken on plants equipped with side-feed stokers—Continued. Boilers Load No. No. used to carry of Steam Instal- Builders No. Pressure lation Type Rated Instal- Aver. Aver. Lbs. per Requirement Nature Character H. P led. Heavy Light sq. in. Load Load l B. & W. Water Tube... . . . . . . . 750 3 3 3 125 Power. . . . . . . . . . . . . . . . . Uniform... . . . . . . . . . . Factory 2 Horizontal Return Tube. . . . . . . 600 4 4 I. . . . . . . . . 90 do . . . . . . . . . . . . . . . . . do ... . . . . . . . . . . do 3 B. & W Water Tube. . . . . . . . . . 1,500 6 4 . . . . . . . . . 90-100 do . . . . . . . . . . . . . . . . . Variable... . . . . . . . . . . do 1 Wickes do ... . . . . . . . 4 2 Stirling do ... . . . . . . . 1,100 3 2 2 110 do . . . . . . . . . . . . . . . . . Uniform... . . . . . . . . . . do b B. & W. do ... . . . . . . . 2,500 5 3 1. . . . . . . . . 150 do . . . . . . . . . . . . . . . . . Variable... . . . . . . . . . . Mill 6 E. & W. do ... . . . . . . . 500 2 1 l 115 Power & heat. . . . . . . do ... . . . . . . . . . . Bldg. 7 Heine do ... . . . . . . . 668 4 3 2 125-130 do . . . . . . . . . . . do ... . . . . . . . . . . do 8 Horizontal Return Tube. . . . . . . 200 2 1 . . . . . . . . . 100 O . . . . . . . . . . . do ... . . . . . . . . . . Factory 9 do . . . . . . . . . . . . 750 5 5 1. . . . . . . . . 100 Power & refrigeration.....] Uniform... . . . . . . . . . . do 10 Wickes Water Tube. . . . . . . . . . . 800 2 2 |. . . . . . . . . 140 Power. . . . . . . . . . . . . . . . . Variable... . . . . . . . . . . Shop 11 Erie City Fire Tube. . . . . . . . . . . 150 1 1 |. . . . . . . . . 100 Power & heat. . . . . . . . . . . do ... . . . . . . . . . . Factory 12 B. & W. Water Tube... . . . . . . . 10,000 20 15–20 6-10 165 Power. . . . . . . . . . . . . . . . . do ... . . . . . . . . . . Power 13 (a) B. & W. do ... . . . . . . . 1,600 4 3 1 150 do . . . . . . . . . . . . . . . . . do ... . . . . . . . . . . do (b) Stirling do ... . . . . . . . 1,600 4 3. 1 150 do . . . . . . . . . . . . . . . . . do ... . . . . . . . . . . do 14 (a) Heine do ... . . . . . . . 750 2 2 1 145 do . . . . . . . . . . . . . . . . . do ... . . . . . . . . . . do % Heine do ... . . . . . . . 650 2 2 1 145 do . . . . . . . . . . . . . . . . . do ... . . . . . . . . . . do (c B. & W. do 1,600 4 4 2 145 do . . . . . . . . . . . . . . . . . do ... . . . . . . . . . . do (d) Standard do ... . . . . . . . 900 3 3 2 145 do . . . . . . . . . . . . . . . . . do ... . . . . . . . . . . do (e) Atlas do ... . . . . . . . 250 2 2 O 145 do . . . . . . . . . . . . . . . . . do ... . . . . . . . . . . do 0opop• • • & & & & & • • • ¶opgź’0• • • •= & & & & • • t • • § € £ € œ • ！ **0I°0op• • ø • • • • • • • !! ！! * * * ç • § € &9T(2) 90°0 0opopes s • • • • § € £ € ± •op• • • • • • • • • • • • § ø • • • • • • • ! * • • • • • • • • • • • • • • • • • • • •op* & & & & & & * & ***8w * & & & æ Œ œ • §9I(p) 0opop• • • • • & & & & & & &op• • • • § ø œ • • • I • ø • • • • • • • • || & & • • • • • • § € || • • • • • • • • • •op• • • • • • • • § →8w º € œ • • • § € œ91(2) 0opopſe ç • & & & & & & • • •op• • • • • • • • • • • • • • • • • • • • • • • • • • • • • ► | ► ► ► ► ► • • • • •op• § € & æ Œ œ • • •8*： < ∞, ∞; ∞, ∞ «; • • •9I$ 0opop I. · · · · · · · · · · ·op 1 ） · · · · · · · · · · · · · · · · · · · · · · · · · · · ·� � � » • œ • • • •op ||· · · · · · · · · ·g | · · · · · · · · ·9Ț10) șI 0opop� & & & & & & & & & {ae） èop• • § € ← $ € £ © ®#8�■ ■ ■ ■ ■ ■ ■ ■ ■ &60°0op• • • § € £ º e º º6I！ € ← → • § € œ Œ œZ(q) 0I3Tſoq[[Ox{OeļS= s • • • • § € £ © * *op• ø œ œ s • • • • •98°0• • & s & & & & & &0I"0opå ø œ & & &�6Iœ Œ œ & & & & & • •4.(o)8I I>ſoeņSa：9-,9×,9-,8،0-, †ȚetųIONI«» «» e ø • • • » e «» ） è • ø œ • • • & & &gŤO83°0op■ «» ， «e & Ō Ō Ō * *6I• • • • § § ø ± ø øZZI JºIſoſſ„9”,9X, 0-,? • • • • • • • d • • • • • • • • • • • • H • • • • • • • • • • • • • • || • • • • • • • • • • • • || • • • • • • • * * * I * * * * * * * * * * I * * * * *� � � � � l � • & ș ș.�£I“Oop ||· · · · · · · · · · · · · · · · · · · ·zºſ;IIII t 1 · · · · · · · · · · · · · · · · · · · · · · ·„0“,8op 1 · · · · · · · · · · · · · · · · ·» & | & & & & & & & » º «{{!}op II. · · · · · · · · · · · · · · · · · · ·0°080I01 Zop„0”,9„0-,9IpetnuoN |· · · · · · · · · · · · · · · · · · · · ·& ： & eº e ºu º ç{{!}op• • • • • • • • • • • • • • • • • • •0'98-0’08†Z6 Zx{oe}S3yaf0-,Z，X,-,Z،0-, ZI3.Igņq8ſ^1& & & & & e º ø § ø ± ø § ø • • • • • • & H ≤ ∞ & æ ø § ø ± ø §0I‘Oop«; • • • • • • • • • § € © « » º «º º ? * *9°Z0I8 o09-3 ·op„0”,9„0”,03• • §·«; •·| | | | | | | | | | | || ' ' ] ',«; »§ ø ± ø ± ù ， øZZ°09p || | | | | | | | | || .9:9Į0°ZI8Z 097~3x{084S reºN.48°,„07.03 . . .|]]�. . . 09.0 . . .| | | | | | | | | |†zz’Oop• • • • • • • • • • L • • • • • • • • • • • • • • • • • • • • •OI9 I I. · · · · ·. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Il · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·09°0op ||· · · · · · · · · · · · · · · · · · · ·0°09'†%9 Off′0 o I. · · · · · · · · · · · · · · · · · · · · · · ·„o-,9 ||· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·§ ø ± ø § ø ± •ÇI’0op ||· · · · · · · · · · · · · · · · · · · ·†”88†Z† STOĻAA JO BI8I’O Iop„0”,țx,0-,ﺄ0”,9| | | | | | | | | | | | | | | | | | | || ... . . . . . . . .]]ș º ſe º ș ș & 1 & » æ ø œ œ • • • • op iſ · · · · · · · · · · · · · · · · · · ·0'98†Z9 Țx{oeņs qy„0”,9×,0~,9Lo-Lot ||· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·%}op ||· · · · · · · · · · · · · · · · · · · ·0°08ţ，Ø IJeſſoq�0-,8×,0-,9،O-,9queſēIºu!ogro I. · · · · · · · · · · · · · · · · · · ·ZI’0IeInąeNș » «， » » «， ！» e º ſº || & * * * * * * $ $ $ | € £ € œ • • • • & și†ZI →IppſūI QV-queņs ąsnȚ (suo?) KepÁep(suo?) KepÁep "333 ſx{oe}S13 IſoſſJºđ peop | Iºd *siH | Ied. Teoo | Ied *siH ºpēInJºlſoquºx{8}JO3ūſJO30 eurnſ ºsȚIĞI-Stººlſ493 BIqsºre.QuaqoſqAA9Segī-q093ī£IIæ3}{pup>I Jo ”ONI3.JºtJAAºzĘSOļJºpu (n.qų3}^TACA'e3HſuopąeĮTeqsu I ->{3e3Ssuoņſpuo©ºſ jó 30ueqsțGI°ONI *IºļeAA go seq0uIºpeo"I 33 er：Av 3ūȚqo3318||3ļeľCI3ūņex{ ºpºnuņuoO—suºĄoţs pøø4-øpţs qņ02 pø44ņnbø squoqq uo uøą04 oțop ſo 1,049(7–Z º'IavJ, 157 º TABLE 7–Detail of data taken on plants equipped with side-feed stokers—Continued Dampers Stack Smoke Records Nº. O Total Mins. in one hr. of Aver. #. - Area Inins. per cent Load tion Kind Usual No. Height Size Square of of during position Feet Feet Feet obser- 100 to 80 to Stack Black obser- vation 80 % 60 % Clean Smoke vations. 1 Hand. % open... . . . . . . . . . 1 110'-0" 5'-0" 19.6 60 0.00 0.00 34.50 8.8 Normal 2 do OPeri... . . . . . . . . . 1 60'-0" '-0" 19.6 60 0.00 0.00 45.00 4.0 do 0.00 0.00 53.75 1.0 3 do . . . . . . % open... . . . . . . . . . 2 125'-0" 7'-0" 38.5 60 3.75 3.50 10.75 29.0 do 115'-0" 4'-0" 12.6 0.00 0.50 52.25 5.0 4 do ... . . . Wide open. . . . . . . . . 3 100'-0" 4'-6" 15.9 60 0.50 0.50 43.50 5.0 do 11'-6" To 103.9 5 do .... Open... . . . . . . . . . . 1 250'-0" 15'-6" bottorn 188.7 60 0.75 1.50 45.00 7.8 do 6 do ..... Nearly closed. . . . . . 1 183'-0" 4'-8" 17.1 60 0.00 0.00 60.00 0.0 Light 7 Automatic l. . . . . . . . . . . . . . . . . . . . 1 220'-0" 5'-0" 19.6 60 0.00 0.50 56.00 2.4 . . . . . . . . . . . . . . 8 Hand.... Wide open. . . . . . . . . 1 98’–0° x 3 9.0 60 0.00 0.25 49.00 4.7 Normal 5'-0" Top 19.6 9 do ... . . . do . . . . . . . . . 1 100'-0" 8'-0" bottorn 50.3 60 6.25 2.75 47.00 14.0 do 10 do % open... . . . . . . . . . 1 140'-0" 6'-0" 28.3 60 2.50 5.75 33.25 16.5 do 11 - . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 60'-0" 2'-0" 3.1 60 6.00 3.00 41.25 16.6 do 12 Hand. Varied... . . . . . . . . . . 10 lº. 7'-0" 38.5 60 0.00 0.00 15.00 17.7 do -140'-0" 13 } do o Wide open. . . . . . . . . 2 1-115'-0" 6'-6" 33.2 60 1.75 0.50 53.50 4.4 |. . . . . . . . . . . . . . b) do ... . . . do . . . . . . . . . 4 115'-0" 4'-6" 15.9 60 0.00 0.00 36.25 4.6 . . . . . . . . . . . . . . 6'-0" for 15-0 14 (a) do do . . . . . . . . . 2 145'-0" 3'-6" “ 105- 9.6 60 0.00 0.25 52.50 2.5 F. . . . . . . . . . . . . . } do do . . . . . . . . . 2 125'-0" 4'-6" 15.9 60 0.00 0.00 46.00 5.0 l. . . . . . . . . . . . . . c) do do . . . . . . . . . 2 145'-0" 6'-6" 33.2 60 0.00 0.00 41.00 6.5 ſ. . . . . . . . . . . . . . (d) do ... . . . . do . . . . . . . . . 3 105'-0" 3'-0" 7.1 60 0.00 0.00 47.75 4.0 . . . . . . . . . . . . . . (e) do ... . . . do . . . . . . . . . 1 115'-0" 3'-0" 7.1 60 0.00 0.00 56.75 1.0 l. . . . . . . . . . . . . . Q w- ; * TABLE 7–Detail of data taken on plants equipped with side-feed stokers—Continued. No. of Instal- Remarks. lation I Good equipment, general plant conditions good but not much care used in firing. 2 Old equipment but fairly well installed. General plant conditions poor and much care used in operation. 3 Good equipment, fairly well installed. General plant conditions fair but not much care used in operation. 4 Good equipment, properly installed and fairly well operated. - 5 Good equipment, properly installed, general plant conditions good but not much care used in firing. 6 Both coal and natural gas used. Good equipment with good plant conditions, well operated. 7 New equipment, well installed and operated. 8 Good installation but only fairly well handled. 9 Old equipment, not properly installed and very poorly operated. General plant conditions poor. }} Good equipment, fairly well installed but poorly operated. l - 12 Combustion space somewhat restricted, plant conditions poor. Considerable hooking through front doors during heavy load period. 13 (a) || Combustion chamber ample. Fires hooked considerably but grates usually kept pretty well covered. - (b) | Large combustion chamber with ample refractory surface. . Although fires hooked considerably not much smoke emitted. e - 14 (a) | Combustion chamber ample in all cases. Boilers operate above rating most of time, fired very hard and fires hooked almost continuously. Stacks practically clean at all (b times except when starting or cleaning fires. - % (d) 160 THE SMOKE INVESTIGATION RESULTS OF SURVEY OF SIDE-FEED STOKER PLANTS. Examinations were made of nineteen plants in which the side-feed type of stoker was installed. Pittsburgh coal was used in eighteen of these plants and Yough- iogheny coal in one plant. Slack or nut and slack size fuel was used in eighteen plants and run of mine in one plant. These plants varied in size from 150 to 10,000 boiler horse power, and contained from 1 to 20 boilers per plant. The thickness of the fire varied from 2% to 12 inches, and natural draft was used in all plants. The draft in the furnace at thirteen plants varied from 0.05 to 0.50 inches of water; at the rear of the boiler; in four plants from 0.20 to 0.60 inches of water; and in the stack at two plants from 0.20 to 0.60 inches of water. Steady loads were carried by four plants, and variable loads by ten plants. Observations made upon twenty-one stacks of boilers equipped with these stokers, show the following average conditions ase regards smoke production: 1.9 minutes per hour of smoke equal to or greater than 60 per cent. black, 43.80 minutes per hour when no smoke issued from stack and an average percentage of 7.6 black smoke from ob- servations. Observations on this same class show a max- imum of 9.00 minutes per hour and a minimum of 0.00 minutes per hour smoke equal to or greater than 30 per cent. Maximum of 60.00 minutes per hour and a min- imum of 10.75 minutes per hour in which no smoke issued from stacks; and a maximum of 29.0 per cent. and a mini- mum of 1.0 per cent. black smoke from observations. UNDERFEED STOKERS. This type of stoker differs radically from any other type so far illustrated, in the manner of feeding and burn- ing the coal and getting rid of the clinker. There are at present two well known types on the market, both employ- ing the same underlying principles in feeding and burn- ing the fuel, but varying considerably in their construc- SOME ENGINEERING PHASES 16] tion, general position of fuel bed, and method of getting rid of the clinker. In the type that first appeared on the market, the retorts are placed horizontally the length of the entire fur- * * * * * \\ ºzº Ses== § | t ſº N 3 * § 3 ; TU YER Es. § 3? (E R - Y. º § * A sºrtrata cyl-troer 2E== E. :=|:= | Elā *zºº - N § SNSExº ºccº# N ~ &QN 'º-. §§ ºzº N • *=Tº AGºtt ATOWrºs :- : º zz t Nºvº == º - ******* SSSSSSSSSSR'sº-lº - sº leists SSSSSR" N 2. R Nº. *S. Figure 47—Longitudinal section of underfeed stoker, Jones model. nace. The number of retorts varies with the size of the furnace, and when only one retort is used, it is placed in the center of the furnace. Coal is fed from a hopper placed at the front of the retort as illustrated by Figure Figure 48—Underfeed stoker, Jones model, as applied to Babcock & Wilcox water-tube boiler. 47 by means of a ram actuated directly from a steam cylinder which is placed in front and beneath the hopper so that the coal feeds by gravity to the ram when the latter is withdrawn from the retort. This cylinder also 162 THE SMOKE INVESTIGATION actuates an agitator or auxiliary ram which moves the coal from the front to the back of the retort and dis- tributes it uniformly beneath the fuel bed. This agitator also gives the fuel an upward and backward movement, thereby automatically breaking up the fire at each charge. The fuel for combustion moves from the bottom of the retort up into the region where combustion takes place, and as it approaches this region, the volatile gases begin to distill off and pass through the incandescent fuel bed. Nºo- | || & ſ:º: º| º * # Zº % 52. º º i --~~~º ºs g º ſº ºf sº- - *s ºr ºse sº sº exºs º ºs carrº, sº sº §§§SS$ºSºSSN: º ºxº~. º.º. º º, a .zºº º §§§ ; : : ºg % 5. Ž U W = L iſ g g tº T Figure 49—Underfeed stoker, Jones model, as applied to Heine water-tube boiler. In the presence of the incandescent carbon, the complete combustion of the volatile gases takes place with a short flame. Air, which supports the combustion, is supplied under pressure through tuyere blocks placed along the side and at the top edge of the retort. As the fuel is sup- plied to the fire, a small portion of it, which has not been completely consumed, and the clinker fall off the top of the fuel bed and roll onto a dead plate at the side of the retort. Here, combustion of the remaining unconsumed SOME ENGINEERING PHASES 163 portion of the fuel is completed by the excess air which enters through the tuyeres. On account of the high temperature encountered in the operation of this type of stoker, most of the ash is fused % - º 2% % º % % Z *... º Jºh-EE %2 | - .2.2 % 2% % $4% % ^. * % º Z * º: | N \ H % || || = 2% % 2. º, º %; - º, H., s | %% % 2. - * % %? a ; º2 2%; 2% º - | f 33.3% | % } Z% | ź;2% Ǻ | §3% 2 ×% {{{2|{2. 72, Z. 2% º f % % Z % %22% % Ø * / º % % %22% r º ZZ%. 3% H - % % / ; | #% “ # Ż% w § %2%; % - % % \||.3% ;: Ž § *...*&^ .* %2% º %23. t # % f +r I º | # 2% % T .2% 4.22% Ż ** -- - ź. - |-Jaft -T {T i. - § {T-T- w %. tº H ski, - sº - * %. cº - 2. S$ - #. ~...~~ - #23 7. % - º *: w z - - 㺠º %2%; * #% #º * *...*& % % wº % ‘A’. %2% % *A*ſº 8.5% % % 2. % % % 3% %; % - % Figure 50—Underfeed stoker, Jones model, as applied to Wickes Water-tube boiler. to clinker, which must be periodically removed through the front door by means of a hook. This operation usually re- 164 ; HE SM OKE INVESTIGATION * -In | | r N z N x - t *# e. --~ : * = . W - * ~ * * *. … *: + = " - : Figure 51—Underfeed stoker, Jones model, as applied to a horizontal return tubular boiler. gº d | º ºr C--~ *--~~-º Sºº-ºº: UT *— ſº == 2% % - ſº 3% % uſ % % EE * tº:- 29 - - - º % [III] % º % #º Fºčğ % *-* - ge; ź. : - : - % -- : š. º *::::::::: º: e & - -, * > º - % Figure 52—Underfeed stoker, Jones model, as applied to a Sterling water-tube boiler. SOME ENGINEERING PHASES 165 sults in the production of smoke, especially if the fire is not allowed to burn down somewhat before cleaning. With this type of stoker the fuel and air supplied are automatic- ally regulated, bearing a definite relation to each other and to the load under which the boiler is operating. No arch or refractory surfaces to aid in the combus- tion of the volatile gases is required with this type of stoker, as these gases are intimately mixed and burn with a very short flame, complete combustion taking place within a very short distance from the fuel bed. Ample combustion space should be provided. This allows ample time and space for combustion, when operating at high boiler capacities, and, also aids in giving a better mixture Figure 53—Underfeed stoker, Jones model, as applied to a Scotch marine boiler. of the products of combustion before they meet the cold surfaces of the boiler. In order to eliminate cleaning of these furnaces by hand, a device for removing the clinker from the furnace has recently been applied to the stoker. A set of movable grate bars has been used to replace the dead plates placed at the sides of the retorts. The linker falls on these grate bars and is moved, by their action, to the rear of the furnace, where it is dumped periodically from the furnace into the ash pit by means of a ram pro- vided for this purpose. This ram is actuated by a steam cylinder placed along the side of the furnace. Figure 48 illustrates this type of stoker, Jones Model, as applied to a B. & W. water tube boiler. 166 THE SMOKE INVESTIGATION Figure 49 illustrates this type of stoker, Jones Model, as applied to a Heine water tube boiler. Figure 50 illustrates this type of stoker, Jones Model, as applied to a Wickes vertical water tube boiler. Figure 51 illustrates this type of stoker, Jones Model, as applied to a horizontal return tubular boiler. ſº #A T- £4% s \ } Z º Z % Z º º 2 %2 % Z/Z %24% % %2. 2. º z º º z gŽ&º& Tº. º& -% N,” N% - -& x- º % % % & % Figure 54–Cross section of underfeed stoker, Jones model, as applied to a horizontal return tubular boiler. Figure 52 illustrates this type of stoker, Jones Model, as applied to a Stirling water tube boiler. Figure 53 illustrates this type of stoker, Jones Model, as applied to a Scotch Marine boiler. Figure 54 illustrates the cross section of this type, Jones Model, as applied to a horizontal return tubular. boiler. SOME ENGINEERING PHASES 167 The type of underfeed stoker which has met with favor, especially in the larger power stations in the East, has its tuyere blocks for air admission inclined from the front of the furnace toward the bridge wall, and has its *~ & SN Lº \ ãº) Dº * Sºrſº iſºl ####|E! # H ſº-> º | % tg f IFigure 56—Underfeed stoker, Taylor model, as applied to a horizontal return tubular boiler. - retorts formed between the tuyere blocks and placed across the front of the furnace. The coal is fed to the furnace from a hopper placed across the front of the furnace, as illustrated by Figure 55. It feeds from this hopper by gravity to two rams, one placed a short distance above the other, the lower one being somewhat ahead of the 168 THE SMOKE INVESTIGATION upper one, both of them, however, operating in one of the retorts between the tuyeres. The upper ram receives its fuel from the hopper and forces it into the top of the re- tort. The lower ram receives its charge only as the coal Zzºº - 2%. º, 26.2% º * in zzz.2/./ey/2 - g *** %22% ºxº Figure 57—Underfeed stoker, Taylor model, as applied to a Babcock & Wilcox water-tube boiler. descends from the upper ram, and its stroke should be so regulated that an even fuel bed will be maintained. The inclined furnace allows all refuse to be deposited at the rear of the furnace, and the fuel to be worked downward SOME ENGINEERING PHASES 169 and toward the back, in its process of combustion. The ash which is fused to clinker is deposited on a dead plate at the rear of the stoker and is periodically dumped into the ash pit. Forced draft and automatic regulation of the coal and air supply are also employed with this stoker. The rams for pushing the coal into the furnace are driven by means of crank arms placed at the front of the stoker and which are in turn driven through gears by an engine or a motor. The fan for supplying the air is usually con- nected to this same driving mechanism, especially in Ø ----- - - - - - - - - sº .." *-----" |) § s **-*** *-* A IFigure 58—Underfeed Stoker, Taylor model, as applied to Heine water-tube boiler. smaller installations. This stoker has the advantage over the hand cleaned type, that provision has been made for cleaning the fire instead of being compelled to rake the clinker out by hand. The inclining of the tuyeres and provision for cleaning the fire also permit of the installa- tion of a larger number of smaller retorts, which distribute the heat more uniformly across the entire width of the boiler. Ample space should be provided for the clinker and refuse to gather in, so that it can be dumped from the furnace without breaking up the fire. This will also aid 170 THE SM OKE INVESTIGATION materially in decreasing the length of time required to burn down the fire, preparatory to cleaning. A stoker of this type, Taylor Model, is shown by Figure 56, applied to horizontal return tubular boiler. Figure 59—Underfeed Stoker, Taylor model, as applied to a Sterling boiler. Figure 57 shows this type of stoker, Taylor Model, applied to a B. & W. water tube boiler. Figure 58 shows this type of stoker, Taylor Model, applied to a Heine water tube boiler. SOME ENGINEERING PHASEs 171 Figure 59 illustrates this type of stoker, Taylor Model, as applied to a Stirling water tube boiler. Figure 60 illustrates this type of stoker, Taylor Model, as applied to a Rust water tube boiler. The underfeed stoker has the advantage of positive draft, and hence its operation is independent of weather * || K-2,229 à º % Figure 60—Underfeed stoker, Taylor model, as applied to Rust water-tube boiler. conditions. It meets changes of load quickly, and on test has shown that boilers can be brought from a standstill to a high rating in a very short time. This stoker affords a means for increasing both economy and capacity of plants, which, by gradual growth, have added so many 172 THE SMOKE INVESTIGATION boilers to a stack that the capacity of the stack has been exceeded. In other words, with the additional boilers, the natural draft of the stack is no longer of sufficient in- tensity to supply the necessary air to burn the amount of coal required in order to develop high boiler ratings. A much shorter stack will suffice with the underfeed stoker than is required where natural draft is used. It is only necessary to have enough draft to carry the gases of combustion through the boiler and out of the stack, § 5To do, Ryº STS-5 I- ~ -vy ƺ 2:= i É ~g- F. ar zzº, 22/2/2/2% z/2/2/2/2/2/z A. * z A. e *A*.*.*.*, *2222*, */z 4%%%%2%%%/ * ZZ ** A. z %22%22%2% *. */ZZZZZ 2. z - 22222222% Z. 2 % 2^*.e. z .* º, ZZZZA, Zz)^, Z, ZZZZZZZZZZZZZZZZZZZZZ * - Figure 61—Underfeed stoker, Jones model, as applied to a furnace for heating forgings. This furnace is equipped with a waste-heat boiler. all the air that is required to burn the coal being forced through the fire. These stokers have sometimes been in- stalled under conditions not favorable to their best opera- tion. Under these conditions they have developed powers in excess of boiler rating, and they conform to very stringent smoke laws when using a good grade of low volatile bituminous coal. Attention has been called previously to the applica- tion of the mechanical stoker to the metallurgical furnace. The following cuts represent such installations that are in SOME ENGINEERING PHASES 173 ºſe q ºqº. Inqs44ț¢I **oO & Idōns [[9AA IĶO 9ų4 J0que ſōſ eqq qe 90 eurng$uțąeøq qøTIȚq e 04pøņāđe se ‘ſopou souoſº‘Jox{oqs pººg Iºpun-ż9ºrnºſ） I ````S`S`>NNNNNNNNN （'（--L––L––L– Ø 174 THE SMOKE INVESTIGATION very successful operation, having aided in increasing both the quality and quantity of the product. Figure 61 represents the underfeed stoker, Jones Model, as applied to a furnace for heating forgings. This furnace is equipped with a waste heat boiler. Figure 62 shows the underfeed stoker, Jones Model, as applied to a billet heating furnace at the plant of the Oil Well Supply Company. Figure 63 shows the underfeed stoker, Jones Model, in use with a hot air furnace—sectional plan. TABLE 8—Detail of data taken on plants equipped with underfeed stokers. ; Coal Stoker Furnace. Dimensions and Feet inches. No. - of sº wº Grate Instal- |Commercial sº Quantity Kind of Thickness Frequency Grate to H. S. Front Height lation | Name Size per yr Stoker of Fire of . No. Area Furnace Coking arch Length |Height Tons Inches | Cleaning Width | Length to Coking | Arch Sq. Ft. Front Arch Rear Aver. Min Boiler | Front ' | Back Furnace 1 Pittsburgh Slack 4,500 Taylor 8-12 5 in 24 hrs 3 1. . . . . . . . 5'-0" 5'-0" 5'-8" 5'-6" 0 l. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 do Nut & Slack 9,125 ||Jones 20-30 |4-6 ° 24 * 2. l. . . . . . . . . . g e º 'º & & ſº tº I g g º ºs e º gº 4'-2" gº & º ºs º is 0 l. . . . . . . . . . . . . . . . . . . . . . . . . . 3 do Slack 2,708 do 18-30 || 4-6 ° 24 ** 1 1. . . . . . . . 4'-0" 3'-0" | 10'-0" gº tº ge 0 l. . . . . . . . . . . . . . . . . . . . . . . . . . 4 N y". Nut & Slack 1,600 do 4-16 || 2 * 12 '' 2 . . . . . . . . 3’-2” 3’-2" | . . . . . . . .l..... . . . . 0 l. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Cleve, gas Run of Mine 7,200 do 12–20 4-6 ° 24 * || 12 | . . . . . . . . . e is sº & sº e s & tº is a tº e º e º s s g g g tº º º e º e g tº e º e 0 l. . . . . . . . . . . . . . . . . . . . . . . . . . 6 Pittsburgh Slack 13,000 do 18 3 ** 24 '' 6 1. . . . . . . . 15'-0" | 12'-0" 6'-0" 6'-4" O '-0" '-5" 7 do do 5,350 do 18 3 ** 24 '' 4 I. . . . . . . . . . 2'-0" 1'-6" |. . . . . . . . . . * g g tº gº is 0 * * * * * * * | * * * * * g e s iſ tº gº e º e s ∈ & B 8 do do I. . . . . . . . do 12–24 || 4 ° 24 ° 4 |. . . . . . . . . . # * * * * * * * | * * * * * @ º || 0 & ſº & © gº tº & g º e s tº g 0 l. . . . . . . . . . . . . . . . . . . . . . . . . . 9 do do 1,035 do 12–15 2 ” 24 '' 1 |. . . . . . . .I. ... . . . . . .] 3'-6" 5'-0" 0 10 do do 3,700 do 12–15 || 3 ** 24 * 4 |. . . . . . . . 3'-4" | 2'-11” . . . . . . . . . . . . . . . . . 0 l. . . . . . . . . . . . . . . . . . . . . . . . . . 3. TABLE 8—Detail of data taken on plants equipped with underfeed stokers—Continued. Boilers Load No. No. used to carry of Steam Instal- Builders No. Pressure lation Type Rated Instal- Aver. Aver. Lbs. per Requirement Nature Character H. P. led. Heavy Light sq. in. Load Load I B. & W. Water Tube... . . . . . . . 690 3 2 2 125 Power & Heat... . . . . Variable... . . . . . . . . . . Mfg. 2 Scotch Marine..... . . . . . . . . . . . . 740 2 2 2 100-110 O . . . . . . . . . . . . Variable... . . . . . . . . . . do. 3 B. & W. Water Tube... . . . . . . . 300 1 1 l 115 Power. . . . . . . . . . . . . . . . . . Uniform... . . . . . . . . . . do 4 Horizontal Return Tube. . . . . . . 130 2 2. l. . . . . . . . . 100 Power & heat. . . . . . . . . . . do . . . . . . . . . . . . . . do 5 do . . . . . . . . . 480 12 12 l. . . . . . . . . 90-100 Power. . . . . . . . . . . . . . . . . . Variable... . . . . . . . . . . Mill Wilkins & 6 3.W.s. Co. Water ... . . . . . . . 1,200 6 5 1. . . . . . . . . 120 do . . . . . . . . . . . . . . . . . . do ... . . . . . . . . . . Mfg 7 Heine do ... . . . . . . . 720 4 3 1. . . . . . . . . 120 Power & heat... . . . . . . . . . Uniform... . . . . . . . . . . Bldg. 8 Macnoll do ... . . . . . . . 500 4 3 1. . . . . . . . . 100 do ... . . . . . . . . . Variable # e º - - - - - - - - - - do 9 Horizontal Return Tube. . . . . . . 85 l 1 |. . . . . . . . . 90-100 do ... . . . . . . . . . . Uniform... . . . . . . . . . . Laundry 10 do 240 4 4 I. . . . . . . . . 95 Power. . . . . . . . . . . . . . . . . . Variable... . . . . . . . . . . Mfg. TABLE 8—Detail of data taken on plants equipped with underfeed stokers—Continued. Rating Draft Breeching Average Load. Inches of Water. No. Distance of . Conditions Stack - Installation Heavy Light & Under to Size Where No. of Kind Rear Breech- Base Which nearest Feet In eat S- Ells. Furnace of ing of taken boiler ured. Hrs. per | Coal per | Hrs. per | Coal per Boiler Stack Feet. day day (tons) day day (tons) - 1.5–3.0 in 1 18 25.0 l. . . . . . . . . . . . . . . . . . . . Forced l. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . duct '-0" 4'-0"x4'-0" |. . . . . . . . . . . . 2 2 24 25.0 l. . . . . . . . . . . . . . . . . . . . do 0.25 1. . . . . . . . . . . . . . . . . . . .l. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Stacks on boilers O 3 12 6.0 12 3.0 do 0.42 0.48 |. . . . . . . . . . 0.48 |. . . . . . . . . . . . . . . . . . . . . . do do O 4 12 4.5 |. . . . . . . . . . . . . . . . . . . . do 0.08 |. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . '-0" | . . . . . . . . . . . . . . . . . . . . . . . . 2 5 10 16.0 14 8.0 do | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5'-0" Stacks on 2 boilers 0 6 10 27.0 14 18.0 do . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Stacks on boilers 0. 7 12 10.0 12 8.0 do . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40'-0" . . . . . . . . . . . . . . . . . . . . . . . . . 1 8 24 |. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do - . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.08 9 10 3-5 1. . . . . . . . . . . . . . . . . . . . do 0.10 l. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10'-0" 2'-0"x2'-0" Near Stack 1 10 24 |. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . do * * * * * * * * * * | * * * * * * * * * * | * * * * * * * * * * : * * * * * * * * * * | * * * * * * * * * * H = • * * * * * * * * * * Stacks on boilers O 5 TABLE 8—Detail of data taken on plants equipped with underfeed stokers—Continued. ; Dampers Stack Smoke Records Total Mins. in one hr. of Aver. & Area mins. per cent Load Kind Usual No. Height Size Square of of during position Feet Feet Feet obser- 100 to 80 to Stack Black obser- vation 80 % 60 % Clean Smoke vations. 1 Hand % open... . . . . . . . . . 1 125'-0" 6'-0" 28.3 60 0.00 0.00 35.25 9.0 Normal 0.00 0.00 59.75 0.1 2 do . . . . . . % open... . . . . . . . . . 2 100'-0" 5'-0" 19.6 60 0.00 0.00 59.25 0.3 1. . . . . . . . . . . . . . 3 do . . . . . . Wide open. . . . . . . . . l 100'-0" 3'-0" 7.1 60 0.00 1.50 10.75 16.0 |. . . . . . . . . . . . . . 4 do . . . . . . O . . . . . . . . . 1 60'-0" 3'-0" 7.1 60 0.25 0.50 51.00 2.0 l. . . . . . . . . . . . . . 0.00 0.00 36.75 14.7 5 None. . . . . . . . . . . . . . . . . . . . . . . . . . 6 : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 12.00 1.00 41.50 8.3 Normal 6 do . . . . . . . . . . . . . . . . . . . . . . . . . . 6 110'-0" 3'-6" 9.6 60 0.00 0.00 60.00 0.0 l. . . . . . . . . . . . . . 7 do . . . . . .l. . . . . . . . . . . . . . . . . . . . 1 240'-0" '-0" 28.3 60 0.00 0.00 11.25 16.9 Normal 8 Hand. . . . . . . . . . . . . . . . . . . . . . . . . . 1 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 0.00 0.00 53.50 2.2 . . . . . . . . . . . . . . 9 do . . . . . . Nearly closed. . . . . . 1 50'-0" l. . . . . . . . . . . . . . . . . . . . . . . . 60 0.00 1.00 52.50 3.0 l. . . . . . . . . . . . . . 10 None. . . . . . . . . . . . . . . . . . . . . . . . . . 4 I. . . . . . . . . . . . '-0" 7.1 60 0.00 0.00 45.75 5.0 l. . . . . . . . . . . . . . ; TABLE 8—Detail of data taken on plants equipped with underfeed stokers—Continued. No. of Instal- Remarks. lation. 1 Good equipment, properly installed and well operated. General plant conditions good. 2 Fair equipment, well operated, general plant conditions good. 3 Good equipment in good condition and well operated. General plant conditions good. 4 Old equipment, in poor condition, general plant conditions poor and not much care used in operation. 5 Very old equipment, in poor condition, fairly well installed but poorly operated. 6 Fair equipment, fairly well installed and operated. General plant conditions fair. 7 Good equipment, poorly installed due to cramped quarters. General plant conditions fair. 8 Fair equipment, fairly well installed and operated. General plant conditions very poor. 9 Equipment fairly well installed and operated, general plant conditions fair. 10 Fair equipment, fairly well installed and operated. General Plant conditions good. 180 THE SMOKE INVESTIGATION RESULTS OF SURVEY OF UNDERFEED STOKER PLANTS. Examinations were made of ten plants in which the underfeed stoker is installed. Of these plants, nine used Pittsburgh coal and one used New York & Cleveland gas coal. Slack or nut and slack size fuel was used in nine plants and run of mine in one plant. These plants varied in size from 85 to 1,200 boiler horse power and contained from 1 to 12 boilers per plant. The thickness of fire varied from 4 to 30 inches. However, in a majority of plants the fire was carried from 12 to 20 inches thick. The draft in the duct, in the only plant for which data could be ob- tained, varied from 1.50 to 3.00 inches of water. In the furnaces at four plants, the draft varied from 0.08 to 0.42 inches of water. Steady loads were carried in four plants and variable loads were carried by six plants. As is usual, in the construction of this stoker, no refractory surface was provided over the fire, except in one plant. Observations made upon twelve stacks of boilers equipped with these stokers show the following average conditions as regards smoke production. 1.35 min- utes per hour of smoke equal to or greater than 60 per cent. black. 43.10 minutes per hour when no smoke issued from the stack and an average percentage of 6.5 black smoke from observations. Ob- servations on this same class show a maximum of 13.00 minutes per hour and a minimum of 0.00 minutes per hour smoke equal to or greater than 60 per cent. black. Maximum of 59.75 minutes and a minimum of 10.75 min- utes per hour in which no smoke issued from the stacks; and a maximum of 16.0 per cent. and a minimum of 0.00 per cent. black smoke. : $ TABLE 9—Summary of plant survey with smoke records. Nature of Load Smoke Records. Nurnber. Boiler (1) Number Thickness of Horsepower Type of . Fired by of Fuel of Boilers Per Boiler Number Smoke equal - Plants Fire Per Plant Uni- || Vari- of Per Cent of to or greater Stack Remarks Plant form able | Stacks Black Smoke than 60% black (2) Clean Average per hr. 23.4%|Average per hr. 12.2 min. 29.8 min. These stacks are connec- 54 P’gh Coal 51 |Maximum 66.0% Maximum 40.8 min. 2.8 ' ' |ted to boilers without fire Hand 56 |I Low Volatile 3’ to 24" | 1 to 10 20 to 32 Horizontal Minimum 0.3% Minimum 0.0 min. 0.0 °' ſtile roofs or coking arches return tubular over the fire I Wood 2500 18 Water tube Average per hr. 13.6%|Average per hr. 5.2 min. 34.5 min. Boilers are equipped with 3 Locomotive 30 11 Maximum 25.0% Maximum 13.5 min. 48.5 ' |Dutch ovens and with 3 Two Flue Minimum 4.8% Minimum 1.0 min. 18.8 '' |coking arches greater than 2'6" in length over the fire 33 P’gh Coal All water tube Average per hr 10.5% Average per hr. 2.1 min. 37.6 min. Chain- Slack or Nut 23 Horizontal Maximum 51.0% Maximum 27.0 min. 60.0 ° Grate 33 land Slack in 4" to 8" 1 to 26, 250 to Type 8 36 |Minimum 0.0% Minimum 0.0 min. 0.0 '' Stoker 23 Plants, run 6500 10 Vertical of mine in 10 Type. 33 P’gh Coal All water tube Average per hr 27.2% Average per hr. 14.6 min.[22.8 min. Slack, nut & Horizontal Maximum 63.0% |Maximum 57.5 min. 57.0 ° Front feed 34 Slack, or Run 3" to 24" | 2 to 22 |450 to 7980 |type in most 8 26 60 Minimum 1.1% Minimum 0.0 min. 0.0 '' Avalanche of Mine & C81S6S Type of Slack in 21 Stoker Plants, Crush- ed Run of Mine or Nut Size in 13 Pgh coal in 13 3 Horizontal Average per hr 7.6% Average per hr. , 1.9 min. 43.8 min. Side-feed plants. Return tubu- Maximurn 29.0% Maximum 9.0 min. 0.0 '' Stoker 19 |Youghiogheny/2%" to 12"| 1 to 20 150 to lar 15 Water 4 10 21 ||Minimum 1% Minimum 0.0 min. 10.75 '' in 1 plant 10,000 Tube, 1 Fire Slack or nut Tube. and slack size fuel used in 13 plants. Run of Mine in 1 plant. g Average per hr. 6.5% Pgh Coal in 4 Horizontal Average per hr. 1.35 min. 43.1 min. Under- 9 plants. New Return Tubu- |Maximum 15.0% |Maximum 13.0 min. 59.8 °” feed York and lar 5 Water Minimum 0.0% Minimum 0.0 min. 10.8 °’ Stoker 10 |Cleveland. 4" to 30° | 1 to 12. 85 to 1200 Tube 1 Scotch Gas Coal in Marine 12 1 plant. Slack or nut and slack used in 9 plants and Run of Mine in 1 plant. 1. In a number of cases information on the nature of the load was not obtained. 2. An average of eight minutes per hour of smoke equal to or greater than 60% black constitutes a violation of the city smoke ordinance. SOME ENGINEERING PHASES 185 Appendix I. PREVAILING WINDS. The following table shows the prevailing winds and their velocities during the years 1911 and 1912 as observed at the Pittsburgh Station of the United States Depart- ment of Agriculture Weather Bureau. PITTSBURGH-DIRECTION OF WIND. Jan. Feb. Mar. Apr. May June July Aug. Sep. Oct. Nov. Dec. Annual 1911 SW NW W NW NW NW NW NW NW NW W SW NW 1912 W W NW SW W NW SW SW SE NW W SW W-SW VELOCITY OF WIND IN MILES PER HOUR. Jan. Feb. Mar. Apr. May June July Aug.Sep. Oct. Nov. Dec. 1911 11.5 13.4 15.3 12.8 9.3 10.0 8.5 9.0 9.2 9.3 15.0 11.1 1912 13.7 12.8 11.8 14.6 11.3 9.9 8.5 10.1 9.2 9.9 14.1 13.6 186. THE SMOKE INVESTIGATION Appendix II. POWDERED COAL. The value of powdered coal as fuel, when applied to steam boilers and metallurgical processes has long been known, and appliances for pulverizing and feeding the coal have been on the market for many years. However, despite its many apparent advantages and the simplicity of the process not much progress has been made towards its general adoption, especially as applied to the steam boiler. This is probably due to the fact that no apparatus has yet been perfected which will warrant the adoption of this process in regular plant operation. The operation of feeding and burning the fuel is very simple in principle, consisting in the most successful sys- tems in reducing the coal to a very fine powder and in- jecting it by mechanical means into a furnace, lined with refractory material, along with the necessary amount of air for combustion. During the injecting process the powdered fuel is intimately mixed with the proper amount of air and combustion takes place with total absence of smoke. This process is not subject to the disturbing influ- ence of an excess of air which accompanies the firing of lump coal. The carbon is thus maintained at its ignition temperature while floating in the air supplied, and until its combustion is completed. The use of powdered fuel is generally confined to high volatile bituminous coals, due to the ease with which these fuels ignite. It has been found that only with exceeding considerable care in operation, can anthracite and the low volatile bituminous coals be used, because these fuels con- tain high percentages of fixed carbon. The low volatile bituminous coal and the anthracite coal burn slower and even a most gentle draft will cause much of the fuel to pass through the furnace unconsumed. SOME ENGINEERING PHASES 187 In the most successful systems for burning powdered coal only sufficient draft is induced to move the gases toward the chimney, the air required for combustion being forced mechanically into the furnace simultaneously with the fuel. By employment of this means more time is avail- able for the combining of the fuel. The very low draft required eliminates the necessity for the construction of a tall stack. 8 The usual practice followed out in the construction of furnaces, for the burning of powdered coal, is not to place any baffle or bridge walls in the direct path of the gases where they have any appreciable velocity. These walls are, however, usually placed from twelve to fifteen feet from the burner. Coal is preferably used dry, as wet coal not only has the effect of retarding combustion, but also gives trouble in handling. The fuel is sometimes dried before it is crushed by passing it around a flue through which the chimney gases are drawn. To obtain the best results in the firing of powdered coal, the coal must be reduced to a fineness so that 75 per cent. will pass through a sieve of 200 mesh, and 95 per cent. through a sieve of 100 mesh. To accomplish this result there are various types of grinders in use, but classi- fied mainly according to two general systems. In the first type the fuel is ground by large machines in separate buildings, stored and supplied to the furnace as required; the necessary amount of air for combustion is blown into the furnace with the fuel. In the other types the fuel is first crushed to nut size, fed to the hoppers at the front of the boiler, here it is pulverized and then fed to the fur- nace with the required amount of air for combustion. When properly operated, brick work of the highest Quality is required to withstand the intense heat devel- oped, as ordinary firebrick is soon reduced to slag by the high temperatures attained. A good quality of firebrick will withstand the action of the heat for some months without repair or renewal, provided the furnace is prop- erly constructed and not subject to alternate effects of heating and cooling, which cause the brick work to crack. 188 THE SMOKE INVESTIGATION Excellent results have been obtained by constructing these furnaces of brick made from carborundum slag, but the cost prohibits their general use. The main advantages in the use of powdered fuel may be summed up as follows: 1. Complete combustion and total absence of smoke, when this process is carried out in a properly designed and operated furnace. 2. Losses due to excess air and cooling of furnaces by opening of fire doors are reduced to a minimum. 3. Use of a cheaper grade of bituminous coal, as im- purities have very little effect on the successful operation of the process. 4. The ability to meet sudden changes in load, and reducing to a minimum the labor inherent to firing. Among the disadvantages are: 1. Danger inherent to the storage of large quantities of powdered fuel giving rise in most cities to the enact- ing of laws prohibiting the storage of large quantities of this fuel. 2. Inability to secure, at a moderate cost, a satisfac- tory material to withstand the intense heat developed when operating this type of furnace properly. 3. Tendency of the stronger drafts to carry the fuel through the furnace unburned. The application of this process to the steam boiler has no doubt largely been hampered by the fact that the maintenance cost in daily operation is high, due to rapid deterioration of brick work. The reliability of all devices. as wet applied to boilers, is questionable. It is claimed that savings of 40 per cent. have been made when powdered coal was applied to metallurgical processes, such as pud- dling, heating and reheating furnaces, and that smokeless Operation was obtained in all cases. t is ºui w A* tº H% ºf , 9 º' gº gº º' Nº. Ag a º T I I I I I I I I I I I I IT || | | | | | | | | | | | | | | | | | | | | || Tº ſº I T | | | | | | | | | | | | | | | | || | | | | | | | | | | | | | | | | | | | | | | […] [T || | | | | | | | | | | | | | | | | | || | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | || | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | || ſº I || | | | | | | | | | | | | | | | | | | | | º | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | || T I I I I I I I I I I I I I . . is Ea • g | | | | | | || || || || ſº tº ºur y A * * * * * * * * * * * twº g º a tº º sº Figure 63—Ringlerman tº geºlv Ainy ºt, as ºut gºtº Uk-Agiº sº [º 1" a tº us y Avg.sv to st PR = < * * * * * * * * Smoke Chart, 189 SOME ENGINEERING PHASES 191 Appendix III. THE CONSTRUCTION OF THE RINGLEMAN SMokE CHART. A rule by which the cards may be produced is given by Prof. Ringleman as follows: Card 0. All white. Card 1. Black lines 1 mm. thick, 10 mm. apart, leav- ing spaces 9.0 mm. square. Card 2. Lines 2.3 mm. thick, spaces 9.0 mm. square. Card 3. Lines 3.7 mm. thick, spaces 6.3 mm. square. Card 4. Lines 5.5 mm, thick, spaces 4.5 mm. square. Card 5. All black. These lines and spaces are so arranged that the black covers respectively 0, 20, 40, 60, 80 and 100 per cent of the white surface of the card. These percentages are graded for convenience as smoke numbers 0, 1, 2, 3, 4 and 5, so that number 0 signifies no smoke or a clean stack; and number 4 signifies a stack which is emitting an 80 per cent. black smoke, or for convenience the percentage of black smoke can be obtained by multiplying the smoke number by twenty per cent. METHODS OF TAKING SMOKE) READINGS. In making observations of the smoke proceeding from a chimney, four cards ruled like those in Figure 63, to- gether with a card printed in solid black and another left entirely white, are placed in a horizontal row and hung at a point 50 feet from the observer, and as mearly convenient in line with the chimney. At this distance the lines become invisible, and the cards appear to be of dif- ferent grades of gray, ranging from very light gray to almost black. The observer glances from the smoke com- ing from the chimney to the cards which are numbered 192 THE SMOKE INVESTIGATION from 0 to 5; determines which card most nearly corre- sponds to the color of the smoke, and makes a record ac- cordingly, noting the time. Observations should be made continuously during, say One minute, and the estimated average density for that minute recorded, and so on, rec- ords being made once each minute. The average of all the (records made during the period of observation is taken as the average figure for the smoke density. Readings of one hour or longer in duration were made on each stack observed in the survey and the density of the smoke issuing from the stack tabulated each quarter of a minute according to the method specified. To deter- mine the total number of minutes that any one grade of smoke was emitted from a stack, the number of read- ings of smoke intensity of this grade were taken and di- vided by four, thus giving the smoke minutes. To deter- mine the per cent. of black smoke from readings taken, or average smoke density, the following rule was followed: Smoke Units X 0.20 Percentage of density = Stack Minutes SOME ENGINEERING PHASES 193 º 10. Appendix IV. RULES TO AID IN ABATING SMOKE AND TO INCREASE EFFICIENCY WITH HAND FIRING. Fire evenly and regularly. Fire moderate amounts of coal at a time and place the coal where it is needed. Keep the fire clean, even, and bright all over; do not allow it to burn into holes or thin spots. Break up the lumps and have the coal as nearly as possible uniform in size. Do not fire any lumps larger than a man’s fist. When a fire has burned into holes, do not throw green coal on the bare grates, but push incandescent fuel into these spots before firing. Regulate the draft, and air supply to suit the fire. Watch the condition of the fire and the steam gauge together. Do not fire large quantities of coal. Do not level or stir the fires unless absolutely neces- sary, and then use the utmost care. Do not allow ashes and clinkers to accumulate on the side or bridge walls, as this cuts down the effective grate, area and causes other troubles. Do not allow too long intervals between firings. Publications of the Smoke Investigation Bulletin No. 1. Outline of the Smoke Investigation. 16 p. Free. Bulletin No. 2. Bibliography of Smoke and Smoke Prevention. 164 p. Fifty cents. Bulletin No. 3. Psychological Aspects of the Problem of Atmospheric Smoke Pollution. 46 p. Twenty-five cents. Bulletin No. 4. The Economic Cost of the Smoke Nuisance to Pittsburgh. 46 p. Twenty-five cents. Bulletin No. 5. The Meteorological Aspects of the Smoke Problem. 51 p. Twenty-five cents. Bulletin No. 6. Papers on the Effect of Smoke on Building Materials. 58 p. Twenty-five cents. Bulletin No. 7. The Effect of the Soot in Smoke on Vegetation. 26 p. Twenty-five cents. * Bulletin No. 8. Some Engineering Phases of Pitts- burgh's Smoke Problem. 193 p. Fifty cents. *.*.*.*.*.*.* ºſº.”.” ºf f -º-, . * rººs sº it, t → *s.” - *:::::: * -º ºrº ***** s'. ...º. *...*.*.*.* * † -º ºf sº. --Prº *...* :* ; :*º:º º * : *:: * * > -º- **.*