A TREATISE ON PRODUCER- GAS AND GAS-PRODUCERS BY SAMUEL S. WYER, M.E. JUNIOR MEMBER AMERICAN SOCIETY MECHANICAL ENGINEERS MEMBER AMERICAN INSTITUTE MINING ENGINEERS AUTHOR " CATECHISM ON PRODUCER-GAS " SECOND EDITION Second Impression McGRAW-HILL BOOK COMPANY 239 WEST 39TH STREET, NEW YORK 6 BOUVERIE STREET, LONDON, E. G. 1906 UN* " Copyright, 1906, By THE ENGINEERING AND MINING JOURNAL Copyright, 1907, By THE HILL PUBLISHING COMPANY DEDICATED TO MY WIFE. 337627 PREFACE. THE first four chapters are given for the benefit of readers who may not be familiar with those fundamental laws and defi- nitions of physics and applied chemistry upon which a rational discussion of producer-gas must be based. References are cited in the text by means of their bibliographical serial numbers, these being given in Chapter 30. Since the engineering side of gas-producers is so closely related to applied chemistry, tem- peratures are stated either in Centigrade or Fahrenheit; how- ever, as the book is intended primarily for engineers, the Fahrenheit scale is used most. Parts of Chapters 24, 26, and 30 were presented by the author as papers at the Washington, D. C., meeting of the A. I. M. E. The author wishes to acknowledge the courtesy shown him by the builders of American producers in furnishing illustrations and data, and especially to the United Coke and Gas Company for information on their by-product coke ovens. Acknowledgment is also due Messrs. Ledebur, Ramdohr, o Stegmann, and Gradenwitz, of Germany; Ackerman, of Sweden; Ebelmen, of France; Mathot, of Belgium; Rowan, Jenkins, Dow- son, Siemens, Sexton, and Mond, of England; and Taylor, Campbell, Howe, Gow, Raymond, and Nixon, of America, for ideas and suggestions from their contributions to the literature of the subject. In conclusion I wish to thank Prof. N. W. Lord, of the Ohio State University, for suggestions and criticisms on the book. SAMUEL S. WYER. COLUMBUS, OHIO, September, 1905. 5 AUTHOR'S PREFACE TO SECOND EDITION IT is now nearly a year and a half since the manuscript for the first edition left the author's hands. In this brief period the producer-gas industry has grown very rapidly in America. Not only have a large number of manufacturers gone into the business of manufacturing gas producers, but the advantages of the pro- ducer-gas process have become so well known as to make it feasible to adapt producer gas to several new industries. The largest amount of development in the near future will be along the line of developing successful soft coal gas producers for gas-engine work. The changes that have been necessary to bring the second edition up to date have been made by mean's of references follow- ing the section numbers and headings which refer to notes in the Appendix. As for example, 47 Atomic and Molecular Weights (see App., Note 7). In the same way, if the section number is followed by (B 99) the reference is to the bibliography pages 277-290 inclusive. Dr. Richards' "Metallurgical Calculations" have done much toward placing the thermo-chemical problems of gas engineering on a firm basis, and the author is under obligations to him for suggestions. In conclusion the author wishes to thank all those who have been helpful in increasing the value of the book by suggesting changes and making criticisms. SAMUEL S. WYER. HARRISON BUILDING, COLUMBUS, OHIO, March 15, 1907. CONTENTS, CHAPTER I. FUNDAMENTAL PHYSICAL LAWS AND DEFINITIONS SECTION. pAGE 1. Importance of laws 21 2. Forms of matter ... ....... 21 3. Perfect gas 21 4. Distinction between a vapor and a gas . 21 5. Vapor tension 22 6. Vapor pressure 22 7. Saturation . . . 22 8. Humidity 23 9. Absolute humidity ........ 23 10. Relative humidity '........., 23 11. Boyle's or Mariotte's law ...... 23 12. Law of Charles 23 13. Laws of Boyle and Charles combined ...... 23 14. Joule's law of gases 24 15. Law of Gay-Lussac . . . J , . . 24 16. Dalton's law ./.''.'..,'.,'.'-... 24 17. Temperature . . . . 24 18. Thermal capacity ....,,....,. 24 19. Specific heat 24 20. Specific heat of gases 24 21. Heat unit .......... e ^ .... .25 22. Density of gases .<.-../ ......... 25 23. Specific volume .... , . 25 24. Specific gravity 25 25. Standard conditions 25 26. Parallel and opposite currents ....,.-.-' 26 27. Radiation 27 28. Flow of gases .............. . 28 29. Equation of pipes 28 CHAPTER II. FUNDAMENTAL CHEMICAL LAWS AND DEFINITIONS. 30. Division of matter 30 31. Atoms and molecules 30 32. Chemical affinity 30 7 ** * : V . v : ::..' ,, *, * * .:{:: : .-;. * ' CONTENTS. PAGE SECTION. . ^ 33. Laws of thermal chemistry . 34. Endothermic reaction 35. Exothermic reaction . ,. . 36. Law of definite proportion . 37. Law of multiple proportion 38. Nascent state ...... 39. Oxidation 40. Reduction 41. Combustion .... 42. Temperature of combustion 43. Dissociation 44. Dissociation temperature oo 45. Heat of decomposition . 46. Flame 47. Atomic and molecular weights . 48. Destructive distillation 49. Fractional distillation 50. Direct-firing . . . 51. Gas-firing . CHAPTER III. THERMAL AND PHYSICAL CALCULATIONS. 52. Determination of the specific heat of a mixed gas 53. Determination of the calorific power of a mixed gas 35 54. Carbon ratio . . . 55. Calculation of volume of gas 56. Theoretical combustion . 57. Weight of a mixed gas 58. Specific gravity of a mixed gas 59. Composition of gases by weight 60. Air required for combustion . 40 61. Weight and volume of products of combustion . 41 62. Heat carried away by products of combustion . 42 63. Sensible heat loss of producer-gas . 42 64. Flame temperature . 65. Explosive mixtures ... .43 66. Calculation of moisture in air . . -. - .' 44 CHAPTER IV. COMMERCIAL GASES. 67. Definition of commercial gases . . . . ... . . . 45 68. Hydrogen . > 45 69. Marsh gas v . . v . . v . . 46 70. Olefiant gas . *., ..... 46 71. Carbonic oxide ........... 46 CONTENTS. 9 SECTION. PAGE . 72. Carbon dioxide ........ 46 73. Oxygen .... 47 74. Nitrogen 47 75. Hydrocarbons * 47 76. Water vapor ^ . .' . 47 77. Air 48 78. Illuminants 48 79. Natural gas 48 80. Oil gas 48 81. Coal gas 49 82. Coke-oven gas 49 83. Water gas 49 84. Carbureted water gas . . . . . . . . . . o 49 85. Comparison of commercial gases . . . . . . . . .* 49 86. Tabulated data ~ .>.... . . . 50 CHAPTER V. STATUS OF PRODUCER-GAS. 87. Progress made . . . ^ . .. t . t 52 88. Ignorance . . . . ' . . . . - . . " . . . o . . 52 89. Fuel supply 53 90. Inadaptability 54 CHAPTER VI. CLASSIFICATION OF GAS-PRODUCERS. 91. Method of operation 55 92. Method of supporting fuel 55 93. Place of removing gas 56 94. Means of agitating fuel 56 95. Nature of draft . . ,. . . . . , . ^_ . . . . .56 96. Direction of blast . . ^ . . ... _ . . 56 97. Continuity of operation . . . . -. . ..- . . .- . . . 56 CHAPTER VII. MANUFACTURE AND USE OF PRODUCER-GAS. 98. Nature of producer-gas . . ..*'..... . ', . . 57 99. Simple producer-gas ..-.,. 57 100. Steam-enriched gas 58 101. The action in gas-producer ....... . .... 58 102. Ash zone 58 103. Combustion zone 60 104. Decomposition zone ........ ^ 60 105. Distillation zone 60 106. Hydrocarbons 60 10 CONTENTS. PAGE SECTION. 107. Condition of fire . 108. Temperature of gas . * 109. Pre-heating air . . 110. Uses of producer-gas 111. Advantages of gas-firing 112. Regenerators . 113. Recuperation . 114. Comparison of regeneration and recuperation 115. Value of regeneration and recuperation . CHAPTER VIII. USE OF STEAM IN GAS-PRODUCERS. 116. Object . . 117. Action . 118. Effect of temperature on action 1 19. Function of steam 120. Proportion of air and steam 121. Quantity of steam . . . 122. Mechanical effect . 123. Water vapor . 124. Summary . 71 125. Steam blowers 126. Types of steam blowers . . .74 CHAPTER IX. CARBON DIOXIDE IN PRODUCER-GAS. 127. Presence . . . 128. Effect of temperature and fuel bed 129. Effect of feeding 80 130. Effect of leakage ... 81 CHAPTER X. EFFICIENCY OF GAS-PRODUCERS. 131. Heat loss . 132. Definition of efficiency 133. Two kinds of efficiency 134. Relation of utility and efficiency 135. Relation of efficiency and calorific power . 136. Method of finding efficiency . , 137. Conditions governing efficiency 138. Coal and ash analysis .... 139. Grate efficiency . ..." 85 140. Heat of combustion of fuel ..... .85 141. Temperatures . . 85 CONTENTS. 11 SECTION. PAGE. 142. Figure of merit 85 143. Limited use of figure of merit 86 144. Cold-gas efficiency 87 145. Hot-gas efficiency 87 146. Effect of steam on efficiency 88 CHAPTER XL HEAT BALANCE OF THE GAS-PRODUCER. 147. Heat losses 89 148. Arrangement of heat balance 90 149. Calculation of heat balance 90 CHAPTER XII. FUEL. 150. Early fuels 94 151. Character of fuel ... 94 152. Condition 94 153. Size of fuel 95 154. Coal 95 155. Peat 95 156. Brown coal 96 157. Refuse 96 CHAPTER XIII. REQUIREMENTS. 158. Adaptability 97 159. Construction of producer 97 160. Composition of gas ... 97 161. Automatic feeding . 97 162. Continuity of operation 97 163. Agitation of fuel bed ~ 98 164. Removal of ashes . 98 165. Deep fuel bed . . 98 166. Introduction of blast 98 167. Cleanliness 98 168. Ease in starting . . 99 169. Regulation of steam and air .99 170. Heat insulation 99 171. Grate efficiency 99 172. Conservation of heat energy 99 CHAPTER XIV. HISTORY OF GAS-PRODUCERS. 173. Chronological record 100 174. Early use 102 12 CONTENTS. cnm. 175. Conservatism in improvement . . . . ^ ' . 1 176. Want of appreciation . ... . . * 177. Bischof producer . . . . .. .. ^ 178. Ebelmen s producers ....... r * 179. Ekman producer ..........- - l 180. Beaufume producer . . . 1 181. Wedding producer . 1 182. Siemens producer . ' " CHAPTER XV. AMERICAN PRESSURE PRODUCERS. 183. Taylor fluxing producer . 184. Liangdon producer 185. Fuel gas and Electric Engineering Co.'s producer . .116 186. Kitson producer . . 187. American Furnace and Machine Co.'s producer . 188. Amsler producer . 189. Swindell producer . .119 190. Forter producer . . 191. Smythe producer . 125 192. Duff producer .... 125 193. Taylor producer 126 I'M. Wood double-bosh producer .130 195. Wood water-seal producer . 131 196. Wood Hat-grate producer . .132 197. Wood single-bosh water-seal producer . .132 198. Wellman producer . . 132 199. Fraser-Talbot producer . ... 132 200. Morgan producer ..... .137 201. Loomis producer 139 202. Wile automatic producer 143 203. Wile water-seal producer 145 CHAPTER XVI. AMERICAN SUCTION GAS-PRODUCERS. 204. History of development 146 205. Definition of "suction gas-producer" 146 206. Classification 146 207. Operation 147 208. Steam supply and regulation . ........ 147 209. American suction producers 147 210. Nagel suction producer ............. 148 211. Pintsch suction producer 150 212. American Crossley producer 152 CONTENTS. 13 SECTION. p AGE . 213. Fairbanks-Morse suction producer 159 214. Smith suction producer , 161 215. Baltimore suction producer 164 216. Wyer suction producer 165 CHAPTER XVII. GAS-CLEANING. 217. Object of cleaning 169 218. Classification of methods 169 219. Deflectors . . . . - 170 220. Liquid scrubbers , 172 221. Coolers 172 222. Absorbers or filters 172 223. Rotating scrubbers 174 224. Proportion of tower scrubbers 176 CHAPTER XVIII. BY-PRODUCT GAS-PRODUCERS. 225. Definition 177 226. Number and value of by-products 177 227. Ammonia sulphate 179 228. Method of recovering by-products 180 229. Mond process 180 230. Distinctive features of Mond process 183 CHAPTER XIX. BY-PRODUCT COKE OVEN GAS-PRODUCERS. 231. Status and future . . . 185 232. Otto-Hoffman oven 185 233. Treatment of gas 188 234. United-Otto oven ....'.' 188 235. Wall construction 190 236. Heating systems 190 237. Operation 190 238. Quencher . . 191 239. Air and water coolers 193 240. Exhausters 193 241. Tar scrubbers , ... 193 242. Ammonia scrubbers 195 243. Recovery of ammonia , 195 244. Benzol recovery , 195 245. Use of gas in engines 196 14 CONTENTS. CHAPTER XX. PRODUCER-GAS FOR FIRING CERAMIC KILNS. PAGE. SECTION. 246. Status . . - 247. Value . , . 248. Objections . . . 249. Difficulties in using producer-gas . 250. Heat losses l 251. Effect of solid fuel constituents . zuu 252. Advantages of producer-gas 201 253. Types of producers for ceramic work CHAPTER XXI. PRODUCER-GAS FOR FIRING STEAM BOILERS. 254. Field for use . . 255. Principle . 256. Advantages . 257. Requirements 258. Results . . . 259. Methods of firing . CHAPTER XXII. WOOD GAS-PRODUCERS. 260. Field for use . . 261. Types of producers . 262. Lundin flat-grate gas-producer 263. Lundin stepped-grate gas-producer 215 264. Riche distillation producer . . . 265. Riche double-combustion producer . . 220 CHAPTER XXIII. REMOVAL OF TAR FROM GAS. 266. Object and difficulties of removal .._..... . .222 267. Nature of tar . . . . . . 268. Influence of temperature 269. Elimination of tar ..... . . 223 CHAPTER XXIV. GAS-PRODUCER POWER PLANTS. 270. Status ...... . . . . . . . .... . .228 271. Ignorance . . . . ' ........ ..... 228 272. Newness of work . . ..... . . . . . / . .228 273. Inadaptability . . . . . . . ... ... . . .229 274. Fuel economy has not been imperative . .... . . . 230 CONTENTS. 15 SECTION. PAGE. 275. Smoke nuisance 230 276. Labor 230 277. Cost of installation 231 278. Cost of repairs 231 279. Use of cheap fuels . 232 280. Scrubbing of gas 232 281. Fuel economy during hours of idleness 232 282. Time required to start producer , . 232 283. Time required to stop producer 232 284. Composition of gas 233 285. Thermal efficiency and economy 233 286. Automatic feeding 233 287. Rate of gasification 233 288. Poking the producer 235 289. Calorific value of producer-gas 235 290. Fuel economy .235 291. No loss from condensation 235 292. Leakage of gas .235 293. Saving in shafting . .... 236 294. Floor space ;- . . . 236 295. Control of operation . .- . 236 296. Dual use of gas 236 297. Storing of heat energy 236 298. Economy of water 236 299. Driving isolated machines . 237 300. Range of sizes 237 301. Danger of explosion 237 302. Location of producer plant . 237 CHAPTER XXV. OPERATION OF GAS-PRODUCERS. 303. Erection ... . . . ... . . '. . ,, / . , . . 238 304. Starting producer ... . . . . ....... . 238 305. Starting engine ', , ., * . ; ., * 239 306. Stopping producer . . -. ^ . . . .' ';' . .,/.' . . 240 307. Running producer . . . . i . : . . . .'".'. . 240 308. Cleaning of plant , .* . 1 . . .240 309. Producer troubles 241 CHAPTER XXVI. TESTING GAS-PRODUCERS. 310. Object of code ... 243 311. Object of test 243 312. Value of test 243 313. Determination of object . . . . ....... 243 16 CONTENTS. SECTION. 314. Examination of producer 245 315. General condition of producer 245 316. Character of fuel ... 245 317. Calibration of apparatus 245 318. Auxiliary boiler . . 246 319. Heating of producer . 246 320. Duration of test . . .... 246 321. Starting and stopping a test .246 322. Uniformity of conditions ... ........ 246 323. Keeping the records 246 324. Quantity of steam ... 247 325. Quality of steam 247 326. Measurement of ashes and refuse 247 327. Sampling the fuel and determining its moisture 247 328. Calorific tests and fuel analysis 248 329. Gas analysis . 248 330. Calorific value of gas 248 331. Determination of water vapor, tar, and soot in gas 249 332. Report of test 251 CHAPTER XXVII. FUTURE OF THE GAS-PRODUCER. 333. Outlook . 255 334. Producer-gas locomotives 255 335. Producer-gas power plants for marine service 257 336. Producer-gas portable engines 259 337. Future development 261 CHAPTER XXVIII. GAS-POISONING. 338. Danger 263 339. Effect of carbon monoxide . .... .- . '. . . . 263 340. Symptoms of carbon monoxide poisoning 264 341. Effect of carbon dioxide 264 342. Effect of carbon dioxide poisoning 265 343. First aid to sufferer 265 344. Artificial respiration 265 345. Post-mortem effects . 266 CHAPTER XXIX. REFERENCE DATA, p. 267 CHAPTER XXX. BIBLIOGRAPHY, p. 277 APPENDIX 291 LIST OF ILLUSTRATIONS. FIGS. PAGE. 1. Diagram of vapor tension and pressure 22 2. Zones of a gas-producer 59 3. Diagram of regenerator 64 4. Siemens steam blower 73 5. Siemens steam blower . . 74 6. Thwaite steam blower 75 7. Argand steam blower 75 8. Solid jet steam blower 76 9. Eynon-Evans steam blower 76 10. Curves showing efficiency of bloweio 77 11. Bischof producer 104 12. Ebelmen producer 105 13. Ebelmen producer 106 14. Ebelmen producer 107 15. Ekman producer 108 16. Beaufume producer 109 17. Wedding producer 110 18. Siemens producer 112 19. Langdon producer 114 20. Fuel gas and Electric Engineering Co. 's producer 115 21. Kitson producer 117 22. American Furnace and Machine Co.'s producer 119 23. American Furnace and Machine Co.'s producer 119 24. American Furnace and Machine Co.'s producer ...... 119 25. Amsler producer . ~ . . . 120 26. Swindell producer 121 27. Swindell producer 122 28. Swindell producer 122 29. Forter producer 123 30. Smythe producer 124 31. Duff producer 125 32. Duff producer 126 33. Duff producer . , 126 34. Taylor producer . 127 35. Taylor producer 128 36. Wood double-bosh producer . 129 37. Wood water-seal producer 130 38. Wood flat-grate producer . . 131 39. Wood flat-grate producer * .... 132 40. Wood single-bosh water-seal producer 133 17 18 LIST OF ILLUSTRATIONS. FIGS. PAGE. II. Wellman producer . . . . . . ., . '. 134 42. Fraser-Talbot producer . 135 43. Fraser-Talbot producer 136 44. Morgan producer 138 45. Morgan producer 140 46. Morgan producer plant 141 47. Loomis producer 142 48. Section of Wile automatic producer 143 49. Assembly of Wile automatic producer 144 50. Wile water-seal producer ... 145 51. Wood suction producer 148 52. Otto suction producer 149 53. Weber suction producer 150 54. Backus suction producer 151 55. Wile suction producer 152 56. Nagel suction producer 153 57. Section of Pintsch producer ... 154 58. Assembly of Pintsch producer ~ 155 59. Crossley suction producer 156 60. Section of Crossley suction producer 157 61. Crossley suction producer plant. 158 62. Section of Fairbanks-Morse suction producer . 159 63. Assembly of Fairbanks-Morse suction producer 160- 64. Assembly of Smith suction producer 161 65. Grate of Smith suction producer 162 66. Charging hopper of Smith suction producer ... . 163 67. Assembly of regulation for Smith suction producer ... 164 68. Detail of regulator and superheater for Smith suction producer . 165 69. Baltimore suction producer 166 70. Section of Wyer producer .167 71. Arrangement of Wyer water regulation . . . . ; . . . 168 72. Moisture collector - 170 73. Dust collector 170 74. Moisture collector ............. 179 75. Tar collector ....'.......... 171 76. Tar collector .171 77. Film scrubber .-.....,..... 173 78. Gas cooler 173 79. Windhausen scrubber ......... 174 80. Centrifugal scrubber .175 81. Centrifugal scrubber . . 175 82. Mond by-product gas plant Igl 83. Otto-Hoffman coke oven Igg 84. United-Otto coke-oven plant .189 85. Coke quencher 192 86. Condensing apparatus 194 87. Producer for ceramic kilns 202 LIST OF ILLUSTRATIONS. 19 FIGS ' PAGE. 88. Producer for ceramic kilns 203 89. Producer for ceramic kilns 204 90. Producer for ceramic kilns 205 91. Producer for ceramic kilns 206 92. Producer for ceramic kilns 207 93. Producer for firing cement kiln 208 94. Producer for firing cement kiln 209 95. Gas-fired water-tube boiler 212 96. Application of gas-producer to steam boiler .213 97. Lundin flat-grate producer ' . . .215 98. Lundin stepped-grate producer 216 99. Section of Riche distillation producer 217 100. Assembly of Riche distillation producer . . 218 101. Section of Riche double-combustion producer . . . . ... . 219 102. Assembly of Riche double-combustion producer ... . 220 103. Duff-Whitfield producer . " . . . . . . . ... . . .224 104. Poetter producer 225 105. Wilson producer * .... 226 106. Capitaine producer 226 107. Comparative efficiency of steam and gas plants . . ;^--v . . 234 108. Log of gas-producer test 244 109. Gas-sampling apparatus 249 110. Gasoline motor car 260 111. Producer-gas-engine-driven tugboat 261 112. Gasoline traction engine 262 113. Curve of correction factors . 273 LIST OF TABLES. TABLE. PAGE. 1. .Summary of combustion data . 38 2. Explosive mixtures . . . t 44 3. Constituents of commercial gases 51 4. Commercial gases 50 5. Effect of temperature on action of steam 68 6. Effect of steam on composition of gas ... 69 7. Effect of different amounts of steam on gas ....... 70 8. Variation in composition of gas 80 9. Arrangement of heat balance . 91 10. Data and results of producer test . . 251 11. Saturation table 267 12. Relative humidity of air . .... 268 13. Coefficients of radiation . 268 14. Radiation ratios 268 15. Radiation loss in iron pipes , . 269 16. Radiation loss through walls .... ...... 269 17. Efficiency of pipe coverings ... ....... 270 18. Discharge of gas / . . 270 19. Equation of pipes ............... 274 20. Solubility of various gases . . . . . 275 21. Melting points of various salts . . . . . ... . . . 275 22. Variation in specific heat of CO 2 .... 275 23. Mean specific heats .v. . 301 24. Comparison of pressures .......... . 302 20 CHAPTER I, FUNDAMENTAL PHYSICAL LAWS AND DEFINITIONS. 1. Importance of laws. To secure a proper conception of the method of manufacture, the value, advantages, and applications of producer-gas, it is necessary to have a clear understanding of some of the funda- mental laws and definitions of physics and chemistry; these are given in concise form in this and the following chapter. 2. Forms of matter. A solid is a substance which has more or less rigidity of form. A fluid is a substance which has no rigidity of form. A liquid is a fluid capable of having a free surface and of. which the volume is definite. A gas is a fluid of which the volume is limited only by that of the closed containing vessel. 3. Perfect gas. A gas which strictly follows Boyle's law (11) is called a per- fect gas. 4. Distinction between a vapor and a gas. A vapor is a substance in the gaseous state at any temperature below the critical point. A vapor can be reduced to a liquid by pressure alone, and may exist as a saturated vapor in the presence of its own liquid. A gas is the form which any liquid assumes above its critical temperature, and it cannot be liquefied by pressure alone, but only by combined pressure and cooling. The critical point is the line of demarcation between a vapor and a gas. The temperature of the substance at the critical point is the critical temperature. The pressure which at the critical temperature just suffices to condense the gas to the liquid form is called the critical pressure. The following are a few of these: 21 22 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. CRITICAL TEMPERATURES. CO 2 30.92 C. C 2 H 4 9.2 CH 4 -81.8 O . -118. CO -141.1 N. -146. H.. -220. H 2 O -370. CRITICAL PRESSURES. 77. atmospheres. . 58. . 54.9 50. . 35.9 . 35. . 20. 195. 5. Vapor tension. All liquids tend to assume the gaseous state, and the measure of this tendency is the vapor tension of the liquid. 6. Vapor pressure. For a given liquid there corresponds to each temperature a certain definite pressure of its vapor, at which the two will re- --t-- vfc? FIG. 1. DIAG"RAM OF VAPOR TENSION AND PRESSURE. main in contact unchanged. Thus in Fig. 1 the gas pressure, P, of the vapor, V, balances the vapor tension, T, of the liquid L. This gas pressure is said to be the vapor pressure of the liquid at that temperature, and the vapor itself is said to be saturated. The relation between water-vapor pressure at .saturation and temperature is shown in table 11, p. 267= For the application of this, see 331. 7. Saturation. A gas is saturated when its full capacity of a given volume of vapor has been reached. FUNDAMENTAL PHYSICAL LAWS AND DEFINITIONS. 23 8. Humidity. The state of a gas, with reference to vapor that it contains, is called its humidity. 9. Absolute humidity. The amount of vapor actually present is called the absolute humidity for a given temperature. 10. Relative humidity. The absolute humidity divided by the amount of vapor that might exist if the gas were saturated at the given temperature gives a ratio called the relative humidity. This is usually ex- pressed in percentages; thus, air with a relative humidity of 50 per cent has just half as much water vapor in it as it could hold at the corresponding temperature. Table 12, p. 268, gives the relative humidity of air. 11. Boyle's or Mariotte's law. In a perfect gas the volume is inversely proportional to the pressure to which the gas is subjected ; or, what is the same thing, the product of the pressure and the volume of a given quantity of gas remains constant. 12. Law of Charles. The volume of a given mass of any gas, under constant pres- sure, increases from the freezing point by a constant fraction of its volume at zero. In other words, gases expand zh of their volume at degrees C. for each degree C. rise of temperature, and ?5T of their volume at 32 degrees F. for each degree F. rise of temperature. 13. Laws of Boyle and Charles combined. The combination of these two laws shows that the product of the volume and pressure of any mass of gas is proportional to its absolute temperature. Let V = volume corresponding to temp. degrees C., and pressure P = 760 mm. Let v = volume corresponding to temp, t degrees C., and pressure p. v = V+ xtV = V +.00366*7 = 7 (1-f . 00366*). 273 V I + .00366* 24 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. VD But PV-jn, hence - - As the presence of water vapor in a gas also influences its volume, the vapor tension must be taken into account. Let a = vapor tension corresponding to t degrees. For values of a, see table 11, p. 267. 760 (1 + .003660 This may be worked out in a similar manner for Fahrenheit temperatures. 14. Joule's law of gases. No change of temperature occurs when a perfect gas is allowed to expend without doing external work, or without taking in or giving out heat. 15. Law of Gay-Lussac. Equal volumes of all gases at the same temperature and pres- sure contain the same number of molecules. 16. Dalton's law. A mixture of gases, having no chemical action on each other, exerts a pressure which is equal to the sum of the pressures which would be produced by each gas separately, provided it occupied the containing vessel alone at the given temperature. 17. Temperature. (See App., note 1.) Temperature is the measure of the degree of hotness of a body. 18. Thermal capacity. The thermal capacity of a substance is the heat required to raise the temperature of a unit mass of it one degree. 19. Specific heat. The specific heat of a substance is the ratio between the ther- mal capacities of equal masses of the substance and water. 20. Specific heat of gases. (See App., note 2.) A gas has two specific heats, depending on whether it is kept at constant volume or at constant pressure while being heated. The specific heat of gases also varies with the temperature. This is shown in table 22, p. 275. FUNDAMENTAL PHYSICAL LAWS AND DEFINITIONS. 25 21. Heat unit. (See App., note 3.) The unit quantity of heat, or the heat unit, is the heat required to raise the temperature of a unit weight of water one degree. The heat required to raise one pound of water one degree F. is called a British thermal heat unit, B. t. u. The heat required to raise one gram of water one degree C. is called a gram-calory. The heat required to raise one kilogram of water one degree C. is called a calory. The heat required to raise one pound of water one degree C. is called the Centigrade unit, C. u. 22. Density of gases. The density, or the specific weight, of a gas is the mass con- tained in a unit volume of the gas. Column G, table 3, p. 51, gives the density of various gases where the unit of volume is the cubic foot. 23. Specific volume. The specific volume of a gas is the number of units of volume which are occupied by a unit weight of the gas. Column H, table 3, p. 51, gives the specific volumes of various gases in terms of cubic feet and pounds. 24. Specific gravity. The specific gravity of a gas is the ratio of its density to the density of another gas taken as a standard. Hydrogen and air are the standards that are generally used. Columns E and F of table 3, p. 51, give the values for different gases. The specific gravity of producer-gas is usually about 0.86- with reference to air. For the method of calculating the specific gravity of pro- ducer-gas, see 58. It must be remembered that the specific gravity of a gas is affected by the pressure of the gas, and for that reason the values are referred to a standard condition (see 25). Thus, if the gas pressure is 10 per cent more than that for the standard con- dition, the specific gravity will also be increased about 10 per cent; if the gas pressure is less than the standard, the specific gravity will be decreased by about the same per cent. 25. Standard conditions. Since the volume of a gas varies with the temperature and pressure, in order to secure comparable results in gas calculations 26 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. a standard condition is necessary. This is usually taken as degrees C. and a pressure of 760 millimeters of mercury, abbre- viated degrees C., 760 mm.; or its equivalent, 32 degrees Fahren- heit and a pressure of 29.92 inches of mercury, abbreviated 32 degrees F., 29.92 in. 26. Parallel and opposite currents. The construction of most gas-producers used for power pur- poses is such that the gas is cooled by another fluid as it leaves the producer. This makes it desirable to understand some of the fundamental cooling phenomena. On account of limited space in this book, the discussion must be brief. For a detailed discussion the reader is referred to B 190, from which the follow- ing is taken : Two liquids, gases or vapors, one of which is to transfer heat to the other, may be conducted either in the same or in opposite directions over the surface of separation. If the two fluids move parallel to one another in the same direction, this con- dition is known as that of parallel currents. If, however, they move in opposite directions, the condition is that of opposite currents. In the case of opposite currents, the fluid to be cooled and also the fluid to be heated have their highest temperatures at one end and their lowest temperatures at the other; and the cooling medium may flow away at a temperature only slightly lower than the highest temperature of the hot fluid. In the case of parallel currents, the fluid to be cooled has its highest temperature at the commencement, the fluid to be heated its lowest temperature; at the end the reverse is the case, and the cooling medium must always run off at a temperature lower than the lowest temperature of the hot fluid. Parallel currents require much more cooling fluid than opposite currents. Like- wise, in order to heat a cold fluid by means of a hot fluid, much more hot fluid must be used with parallel than with opposite currents. Further, the greatest difference in temperature occurs between the highest temperature of the hot and the lowest temperature of the cold fluid, the smallest difference in tem- perature between the lowest temperature of the hot and the highest temperature of the cold fluid. The first-named differ- ence is the greatest which arises under any conditions; the second FUNDAMENTAL PHYSICAL LAWS AND DEFINITIONS. 27 is always very much less, which is also the case with opposite currents. Since with opposite currents the highest possible temperature difference can never occur, it follows at once, in general, that the mean difference in temperature is greater with parallel than with opposite currents, and consequently that in the former case the necessary heating or cooling surface may almost always be smaller than in the latter case. An opposite-current apparatus is thus always larger than a parallel-current apparatus, but is more efficient, and, in particular with similar materials, permits the attainment of the highest temperatures in heating apparatus and the lowest temperatures in cooling, which it is impossible to obtain with parallel currents. In conclusion, heating and cooling apparatus should always be constructed for opposite currents. 27. Radiation. To secure a high efficiency in any gas-producer, it is impera- tive to keep the radiation loss ( 147) low, and to do this requires a compliance with the laws of radiation. "Radiation of heat takes place between bodies at all distances apart and follows the laws for the radiation of light. The heat rays travel in straight lines, and the intensity of the rays radiated from any one source varies inversely as the square of the distance from the source. Heat rays are reflected according to the law of optics, that the angle of incidence is equal to the angle of reflection." If the temperature difference is small, the radiation loss will depend on the material, area, and temperature difference. Table 13, p. 268, gives the radiation coefficients as determined by Peclet. These coefficients are not reliable for large tempera- ture ranges, since a considerable difference in the temperature of the hot body and the surrounding air causes an increased rate of cooling which varies with the magnitude of the tempera- ture range. These corrections are given in table 14, p. 268. The number of heat units radiated from a given material and area should first be computed by the coefficients of radiation given in table 13, and the result multiplied by the ratio of the respec- tive temperature range as given in table 14. Table 15, p. 269, shows the radiation loss from exposed iron pipes, and is a strong argument in favor of the use of heat insu- 28 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. lators around pipes conveying a hot fluid that is to be kept at a high temperature. Table 16, p. 269, gives the radiation loss through masonry walls, and shows the desirability of enclosing the producer in a suitable jacket. Table 17, p. 270, shows the efficiency of various heat-insulating materials. 28. Flow of gases. (See App., note 5.) The velocity with which a gas under pressure will flow into a vacuum is inversely proportional to the square root of its density. Thus hydrogen, which is sixteen times heavier than oxygen, would, under the same conditions, flow through an opening with four times the velocity of oxygen. Hence, it is evident that the specific gravity of a gas is an important factor in its flow. The motion of gas in pipes may be determined by the follow- ing formulae: H =Head or pressure in inches of water. Q = Quantity of gas in cubic feet per hour. L = Length of pipe in yards. D = Diameter of pipe in inches. G = Specific gravity of gas. D=.056C /Q2X g XL - H Table 18, p. 270, which was calculated by the above formula, gives the discharge in cubic feet per hour through pipes of various diameters and lengths and at different pressures, for a gas of a specific gravity of 0.4. The quantity of gas discharged of any other specific gravity may be determined by means of the curve given in Fig. 113. To apply this, multiply the quantity indicated in table 18 by the correction factor corresponding to the particu- lar specific gravity. Thus, for a gas with a specific gravity of 0.85, the quantity indicated in table 18 must be multiplied by 0.685. 29. Equation of pipes. The volume delivered by two pipes of different sizes and the same velocity of flow is proportional to the squares of their FUNDAMENTAL PHYSICAL LAWS AND DEFINITIONS. 29 diameters; thus one 4-in. pipe will deliver the same volume as four 2-in. pipes. However, with the same head the velocity will be less in the 2-in. pipes on account of the larger amount of sur- face friction in the latter, and the volume delivered varies about as the square roots of the fifth powers of the respective diameters. Table 19, p. 274, has been calculated on this basis. The figures opposite the intersection of any two sizes is the number of the smaller sized pipes required to equal one of the larger. Thus one 5-in. pipe is equal to 9.8 2-in. pipes. CHAPTER II. FUNDAMENTAL CHEMICAL LAWS AND DEFINITIONS. 1 30. Division of matter. Matter may be divided into elements, compounds, and mechani- cal mixtures. A chemically indivisible substance is an element. Elements unite to form new substances called compounds, which may be entirely different from the original elements. A compound may be defined as a substance made up of two or more elements, or it is a substance that may be broken up into other substances. A mechanical mixture is a substance composed of two or more elements not held together by any chemical attraction. Producer-gas is a mixture of other gases. 31. Atoms and molecules. An atom is the smallest particle of an element that can enter into chemical combination. Atoms combine to form molecules of substances. 32. Chemical affinity. The force which holds the atoms of a molecule together is called chemical affinity. 33. Laws of thermal chemistry. The heat evolved or absorbed in any chemical change is fixed and definite, and depends only on that change. If a chemical change evolves or absorbs heat, the reverse change will absorb or evolve exactly the same quantity of heat. Every chemical change effected without the intervention of extraneous forces tends to produce those bodies the formation of which will evolve the least heat. 34. Endothermic reaction. Any chemical change that absorbs heat is called endothermic, and is indicated by the sign-. (See 117.) 1 See App., note 6. 30 FUNDAMENTAL CHEMICAL LAWS AND DEFINITIONS. 31 35. Exothermic reaction. Any chemical change that evolves heat is called exothermic, and is indicated by the sign +. 36. Law of definite proportion. Chemical changes always take place between definite masses of substances. 37. Law of multiple proportion. If two elements form several compounds with each other, the masses of one that combine with a fixed mass of the other bear a simple ratio to one another. 38. Nascent state. An element is in the nascent state if, at the moment of its liberation from a compound, it is characterized by abnormal chemical activity. 39. Oxidation. Oxidation, also called oxidization, is the act or process of taking up, or combining with, oxygen. 40. Reduction. Reduction is the abstraction of oxygen from a compound. 41. Combustion. Combustion is a vigorous chemical combination attended by the evolution of heat and light. It may also be defined as the "burning or chemical combination of the constituents of the fuel, mostly carbon and hydrogen, with the oxygen of the air." 42. Temperature of combustion. A certain temperature, varying with the nature of the com- bustible and air supply, is necessary for combustion. For the calculation of this temperature see 64. 43. Dissociation. When a substance decomposes and splits up into its constitu- ents by the application of heat, in a reversible way, and yields a larger number of molecules than composed the initial body, it is said to dissociate. Thus if CO 2 and H 2 are heated suffi- ciently, they are split up or dissociated into their constituents, the H 2 O being broken up into H and O, and CO 2 into C and O. 44. Dissociation temperature. This is the temperature at which dissociation takes place; it 32 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. is not a fixed point, but varies with the conditions. It is gen- erally lowered by contact with hot solids and raised by the pres- ence of inert gases. 45. Heat of decomposition. In the decomposition of a chemical compound, as much heat is absorbed or rendered latent as was evolved when the com- pound was formed. 46. Flame. A flame is a mass of intensely heated combustible gas. A b-imple flame is one in which there is only one product of com- bustion; if there is more than one product of combustion the flame is compound. 47. Atomic and molecular weights. (See App., note 7.) The atomic and molecular weights of the elements entering into producer-gas are given in columns C and D of table 3, p. 51. A knowledge of these makes it a matter of simple arithmetic to determine how many pounds of each element are in a given weight of the combination. One atom of carbon unites with two atoms of oxygen to form one molecule of carbon dioxide; thus, C -I- 20 = C0 2 , or in pounds, 12 + 2x16 = 12 + 32 12+ 32 = 44 3+ 8=11 That is, 3 pounds of carbon unite with 8 pounds of oxygen to form 11 pounds of carbon dioxide ; or, in other words, to form 1 pound of carbon dioxide there will be required -j\ pound of carbon and j 8 T pound of oxygen. One atom of carbon unites with one atom of oxygen to form one molecule of carbon monoxide. Thus: C+ O = CO 12+16 = 28 3+ 4 = 7 That is, 3 pounds of carbon unite with 4 pounds of oxygen to form 7 pounds carbon monoxide; or, in other words, to form 1 pound of carbon monoxide there will be required f pound of carbon and pound of oxygen. FUNDAMENTAL CHEMICAL LAWS AND DEFINITIONS. 33 In other words, to burn 1 pound of carbon to carbon monoxide, there will be required 1J pound of oxygen, and this will form 2J pounds of the carbon monoxide. 48. Destructive distillation. Destructive distillation is the process of heating a substance beyond the point of decomposition without the access of air. The object may be the dry residue, the condensed distillate, or the gases evolved. The residue will always be carbon. 49. Fractional distillation. This is the separating of different constituents from a com- posite substance. It is made possible by the fact that different substances pass into vapors at different temperatures. 50. Direct-firing. (B 194.) " By direct-firing is meant burning coal or other solid fuel in a fire-box close to the working chamber, and in a layer so .thin that enough free atmospheric oxygen passes through some of the wider crevices between the lumps of fuel, both to burn the carbonic oxide generated by the incomplete combustion of the fuel by the limited quantity of air which passes through other and narrower crevices, and also to burn the hydrocarbons, if any, distilled from the fuel. Thus both the combustible gas and the air for burning it escape simultaneously and side by side from the surface of the fuel, the flame beginning at the very surface of the fuel." 51. Gas-firing. (B 194.) " By gas-firing is meant chiefly burning the fuel in a layer so thick that all of the oxygen of the air which passes through it combines with the fuel, and that nearly all of it forms carbonic oxide with the carbon of the fuel; so that from the surface of the fuel escapes a stream of combustible gas, chiefly the carbonic oxide thus formed, and hydrocarbons from the distillation of the fuel, diluted with atmospheric nitrogen. The stream of gas is in turn burnt by air specially admitted for this purpose." " In short, in direct-firing the fuel bed is so thin that it delivers flame direct from its surface; in gas-firing it is so thick that it delivers there a stream simply of combustible gas. This is the essential distinction." CHAPTER III. THERMAL AND PHYSICAL CALCULATIONS. 52. Determination of the specific heat of a mixed gas. (App., note 2.) The number of heat units absorbed in heating a given volume of a mixed gas through a given range of temperature will be the aggregate number of heat units absorbed by the several con- stituents. The number of heat units absorbed by each con- stituent will be the product of its volume, expressed in cubic feet, and its specific heat per cubic foot. To simplify the cal- culation, we assume that the total 100 stands for 100 cubic feet of the gas; then the percentage of each constituent will stand for the number of cubic feet of the respective constituents in the hundred. This calculation is illustrated by the following ex- ample: C .0077 .1615 1.1577 ' .4404 .1378 .0633 .0115 1.9799 .0198 A Composition of gas in percentage by volume. B Specific heat per cubic foot, column J, table 3, p. 51. C Specific heat of 100 cubic feet of mixed gas. It will be noticed that the specific heats of 0, H, N, and CO are nearly the same. The amount of C 2 H 4 in any ordinary producer-gas is too small to affect the result materially, CH 4 and CO* being the only factors whose variation alters the general value to any extent. The gas analysis given is a representative one, and in ordinary practice the specific heat per cubic foot of producer-gas will not be found to vary much from the value calculated. 34 o.. A .4.. . X B .019 H N .... 8.5... 60.3 ...x.. - . X . .019... 0192 CO CO, CH< .... 22.8.. .... 5.2... 24 ...x.. ...x.. X .. .0193 .. .0265 ' .0264 C 2 H 4 4... .. x. 0289..!..:! !;.!.!.!. 100.0 Spec ific heat of 100 cu. ft. THERMAL AND PHYSICAL CALCULATIONS. 35 53. Determination of the calorific power of a mixed gas. The number of heat units produced by the combustion of a given volume of mixed gas will be the aggregate number of heat units produced by the combustion of the several constituents. The number of heat units produced by each constituent will be the product of its volume, expressed in cubic feet, and its calorific power, expressed in heat units per cubic foot. This calculation is illustrated by the following example: CO 2 A 5.2 Bi C o C,,H 4 .. .. CO H CH 4 N 4 4... 22.8... . .... 8.5... 2.4... 60.3 ..1670... 342 346 1070.... AxB . ...AxB ... .AxB AxB . . - 668 . . = 7797 ..= 2941 ..= 2778 100 cu. ft. gives 14184 B t u 1 cu. ft. gives. . . 141 B. t. u. A Composition of gas in percentage by volume. B Calorific power per cubic foot, column R, table 3, p. 51. C Calorific power in 100 cubic feet of mixed gas. 54. Carbon-ratio. (B 66.) A knowledge of the ratio of the weight of carbon to the weight of hydrogen in a given gas is often desirable. While the amount of hydrogen in the gas for one unit weight of carbon depends primarily upon the amount of the former in the original fuel, yet this proportion is changed by the loss of carbon with the ashes, by the decomposition of the steam, and by Trie loss of carbon and hydrogen with the tar and soot. As a result of these factors, the relative amount of hydrogen in the gas from a unit weight of fuel is always higher than in the original fuel. The " carbon-ratio " may be defined as the numerical value of the total carbon by weight divided by the total weight of hydrogen in a given volume of the gas, and is designated by the C symbols ^' This value will indicate the special conditions H under which the sample of gas from which the ratio was cal- culated was made. The calculation of the carbon ratio is illustrated by the follow- ing: 1 See A pp., note 8. 36 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. CO,.... o A 5.2 4 B ...C. 12 C 6 D 31.2 E (C 24 ..12 4.8 C 2 H... 4 m 2 8 PO 00 Q In. c VL 6 .... 136.8 \j\j o t; H 2 . . 1 .. 8.5 1C 12 6 14.4 CH,... 2.4 m o 4 8 N 60.3 In. 100.0 187.2 14.1 A Composition of gas by volume - number of molecules. B Weights of elements. C Relative weights. D Relative weights of atoms of carbon. AxC. E Relative weights of atoms of hydrogen. AxC. .. 187.2 1Q , Carbon-rat io=r = lo.o 14.1 55. Calculation of volume of gas. (B 66.) The calculation of the volume of gas from a given weight of fuel is illustrated by the following example: E .174 .026 .763 .080 C0 2 ... o. A ... 5.2 .4 B . .123 . . . . C . . . .638. D C 2 H<. CO... H 4 22.8 . . 8.5 . .078 . . .078 . . . . .031. ...1.780. '.'.'.'.'.'.'.'.'. \ '.'.'.'.'.'.'.'.'.'. CHY. N.. . ... 2.4 . . . . 60.3 . .0445.... ... .107. 1 100.0 1.043 A Composition of gas by volume. B Weight of 1 cu. ft. of gas in pounds (column G, table 3, p. 51.) C Weight of component in 100 cu. ft. of gas, AxB. D Proportion by weight of carbon in gas (column K, table 3, p. 51.) E Weight of carbon in 100 cu. ft. of gas, DxC. From the above the carbon in 100 cu. ft. of gas = 1.043 Ib. and the carbon in 1 cu. ft. of gas = .01043 Ib. Volume of gas containing 1 Ib. of carbon=- =96.1 cu. ft. Let K=proportion of carbon in 1 Ib. of fuel. Let G=grate efficiency of producer (see 139). Let Q = carbon actually gasified i.e., total carbon in fuel less that passed through grate. Q = KxG. Hence the volume at standard conditions of producer-gas per pound of fuel =96.1 XQ. 56. Theoretical combustion. (B 66.) The combustible constituents of ordinary producer-gas com- bine with oxygen according to the following reactions: THERMAL AND PHYSICAL CALCULATIONS. 37 + 2H 2 O. CH 4 +4O = C0 2 + 2H 2 O. 2H + O = H 2 O. CO + = C0 2 . In order to determine the amount of oxygen required in each case, it will be necessary to know in what proportion they combine both by weight and by volume. The gravimetric relation i.e., the relative proportion by weight can be determined directly from the atomic weights. The volumetric relation is found by dividing the relative weight of each by its weight per cubic unit of volume. For the discussion of atomic weights see 47. The volu- metric ratios given are not always exact, but are near enough for all engineering calculations. In order .to determine the volume of all the products of combustion, it is necessary to assume that they leave the furnace at a temperature above 212 degrees F., so that the water is in the form of steam. In the following calcu- lations the water vapor is taken at 228 degrees F., which corre- sponds to 20 pounds absolute pressure; at this point the weight of water vapor per cubic foot is .0502 Ib. A detailed calculation for each of the combustion reactions is given in the following: C 2 H 4 Relative weights of atoms 28 Ratio of weight 1 Weight per cubic foot 078 Relative volume 12.7 Ratio by volume 1 cu. ft. 3 cu. ft. 2 cu. ft. T. , , . Ratio by weight Relative volume = . . . - 7 Weight per cu.ft. +6O =2CO 2 +96 = 88 + - 2 ^ = ^ .089 .123 38.3 25.5 + 2H 2 O + 36 + :f .0502* 25.6 2 cu. ft. That is, 1 Ib. of C 2 H 4 unites with 2_4 ib. of to form 2 y 2 Ib. CO 2 , and |- Ib. H 2 O, or, in terms of volume, 1 cu. ft. of C 2 H 4 , unites with 3 cu. ft. of O to form 2 cu. ft. of CO 2 and 2 cu. ft. of H 2 O. CH 4 +4O =CO 2 Relative weights of atoms 16 +64 =44 Ratio by weight 1 +4 = -^ Weight per cubic foot 045 .089 .123 Relative volume 22.2 43.8 22.3 Ratio by volume 1 cu. ft. 2 cu. ft. 1 cu. ft. 2H +0 Relative weights of atoms 2 +16 Ratio by weight 1 + 8 Weight per cubic foot .0056 .089 Relative volume 179. 89.5 Ratio by volume 2 cu. ft. 1 cu. ft. * Water vapor at 228 F. + 2H 2 O + 36 .0502* 44.77 2 cu. ft. = H 2 O = 18 =. 9 .0502* 179. 2 cu. ft. 38 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. CO + O =CO 2 Relative weights of atoms 28 +16 =44 Ratio by weight ...".; 1 + $ = U Weight per cubic foot . . ." 078 .089 J23 Relative volume.. . ..12.8 6.4 12.8 Ratio by volume 2 cu. ft. 1 cu. ft. 2 cu. ft. Since in all practical cases of combustion the oxygen is taken from the air and is there associated with nitrogen, the latter is always a constituent of the products of combustion. That is, with every pound or cubic foot of oxygen burned there will be thrown into the products of said combustion *3.32 Ib. or *3.77 cu. ft. of nitrogen respectively. The following table is a summary of the results just calculated: TABLE 1. QUANTITY REQUIRES FORMS Gravimct- rically 1 Ib. C 2 H 4 1 Ib. CH 4 1 Ib. H 1 Ib. CO V Ib. O 4 Ib. O 8 Ib. O i Ib. O V Ib. CO 2 V- Ib. CO 2 V Ib. CO 2 2 Ib. H 2 O t Ib. H 2 9 Ib. H 2 O 11.38 Ib. N 13.28 Ib. N 26.56 Ib. N 1.9 Ib. N 'i=: i > 1 cu. ft. C 2 H 4 1 cu. ft, CH 4 1 cu. ft. H 1 cu. ft. CO 3 cu. ft. O 2 cu. ft. O .5 cu. ft. O .5 cu. ft. O 2 cu. ft. CO 2 1 cu. ft. CO 2 1 cu. ft. CO 2 2 cu. ft. H 2 O 2 cu. ft. H 2 O 1 cu. ft. H 2 O 11.31 cu. ft. N 7.54 cu. ft. ff 1.88cu. ft. N 1.88cu.ft. N 57. Weight of a mixed gas. The method of calculating the weight per unit volume of a mixed gas is best illustrated by a numerical example based on a gas of the following composition: H....... 10 DPT cent hv volnmp CH 4 . C 2 H 4 ... CO CO,. . . . 4. .... 2. 20. 3 per cent by volume, per cent by volume, per cent by volume. o I N . 60 looT By multiplying these figures (see 52) by the weight of 1 cu. ft. of the respective constituents see column G, table 3, p. 51 the weight of each constituent in the 100 cu. ft. is obtained. Thus: * See 77. THERMAL AND PHYSICAL CALCULATIONS. 39 H 10. X .0056 - .056 Ib. CH 4 4.X. 045 - .180 Ib. CoH 4 2.X.078 = :i561b. CO 20.X.078 -1.560 Ib. CO a . ; . 3.X. 123 = .369 Ib. O , l.X. 089 = .089 Ib. N 60.X. 078 =4.680 Ib. 100. cu. ft.=7.090lb. 1. cu. ft. = .07091b. 58. Specific gravity of a mixed gas. To determine the specific gravity of a mixed gas, first calculate the weight per cubic foot as explained in the previous section. Then: Weight per cu. ft. . ., .,, r 0X07* = Specific gravity with reference to air. =Specific gravity with reference to hydrogen. ^ 59. Composition of gases by weight. Gas analyses are almost invariably stated in percentage by volume, since it is easier to measure a gas than to weigh it. How- ever, it is sometimes desirable to know the composition by weight. The method of calculating this will be illustrated by a numerical example based on the results of 57. From these data the gravi- metric composition may be easily calculated as follows: .056x100 . , , =-T.-p = 0.79 H per cent by weight. 2.53 CH 4 per cent by weight. 7.09 = 2.20 C 2 H 4 per cent by weight. 7.09 = 22.00 CO per cent by weight. 369 ^ Q 1QO = 5.20 C0 2 per cent by weight. 08X1QO = 1 .25 O per cent by weight. Since the specific gravity of a gas with reference to H is equal to half its molecular weight (see column D, table 3) these values may also be used to calculate the analysis by weight. Thus: * See column G, table 3, p. 51. 40 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. Per cent by weight. H ................. 10.X 1- 10. ^ =0.786 CH< ............... 4.X 8= 32. ^X^P- 2.515 C 2 H 4 .............. 2.X14 = 28. ?5 = 2.200 CO ................ 20.X 14= 280. C0 2 ............... 3.X22 = 66. =5.180 I** N ................. 60.X14 = 840. 8410 -66.040 ................. 1.X16- 16. - 1.258 1272. 99.979 . The slight discrepancy between the two methods is due to the fact that, for various reasons, the densities of gases as deduced from their chemical composition do not always agree exactly with the values found by direct experiment. 60. Air required for combustion. To determine the theoretical amount of air required for com- bustion of producer-gas, proceed as follows: Multiply the values given in columns O or P of table 3 depending upon whether the results are to be, and the gas analysis is, in terms of weight or of volume respectively by the percentage of the respective combustible constituents of the gas, the sum of these products giving the desired value. Thus: H .......... 10.X 2.39= 23.9 CH 4 ........ 4.X 9.56= 38.24 C 2 H 4 ........ 2.X 14.34= 28.68 CO ......... 20.X 2.39= 47.80 CO 2 ......... 3. 138.62 cu. ft. =air required for 100 cu. ft. gas. O .......... 1. 1.38 cu. ft. =air required for 1 cu. ft. gas. N .......... . 60. 100. However, since this particular gas contains some free O, the amount of air that must be furnished for combustion will be de- creased by an amount equal to the amount of air that the free O represents. Thus: 1 X 4.782* = 4.782 cu. ft. less air than is required per 100 cu. ft. of gas. Actual theoretical amount of air required to burn 100 cu. ft. gas = 138.62-4.782 = 133.838 cu. ft. * See 77. THERMAL AND PHYSICAL CALCULATIONS. 41 The actual amount of air required for the combustion of the gas will be the theoretical amount plus the per cent of air excess, 61. Weight and volume of products of combustion. The weight and volume of the products of combustion of producer-gas are calculated by means of the factors given in table 1, p. 38. A volumetric numerical case will be worked out with a producer-gas of the following composition: H 10. per cent by volume. CH 4 4. per cent by volume. C 2 H 4 2. pe'r cent by volume. CO 20. per cent by volume. CO 2 3. per cent by volume. O 1 . per cent by volume. N o 60. per cent by volume. 100. per cent by volume. C0 2 H 2 N VI -.n IX 1 10. 18.8 [X 1.88 (X 1 4 CH, . 4, X 2. . 8. C 2 H 4 .. .... ... 2. CO . . . 20. X 7.54 ..... 30.16 X 2 4. X 2 4. Xll.31 22.62 X 1 20. X 1.88 . 37.60 CO 2 3. 28. 22. 109.18 1. N 60. 100. That is, in burning the combustible constituents of 100 cu. ft. of gas of the composition given, we would get 28 cu. ft. CO 2 , 22 cu. ft. H 2 O and 109.18 cu. ft. N. These results will be modified, however, by the non-combustible or diluent constituents of the gas namely, CO 2 , O, and N. Since in every 100 cu. ft. of the gas in question there are 3 cu. ft. of C0 2 , which go into the pro- ducts of combustion, the latter will be augmented by that amount. The 1 cu. ft. of O in the gas will decrease the amount of O and associated N that must be furnished by the air for the burning of the combustible constituents; i.e., there will be 3.77 cu. ft. of N less in the products of combustion due to the 1 cu. ft. of free O in the gas. The 60 cu. ft. of N in the gas will simply increase the products of combustion by a corresponding amount. The corrected values are as follows: 42 A TREATISE ON PRODUCER^GAS AND GAS-PRODUCERS, C0 2 =28 + 3 = 31 cu. ft. H 2 O = same as before, 22 cu, ft. N = 109.18-3.77 + 60. = 165.41 cu. ft. The above may be worked out in a similar manner in terms of weights by means of the gravimetric factors in table 1, p. 38, and a gas analysis in per cents by weight. In ordinary practice, the products of combustion will also contain air due to the air excess used in burning the gas. Thus, if in burning the gas for which we have just calculated the volumes of the products of combustion we use an air excess of 25 per cent, we will then re- quire 1.33+ 1.33X.25 = 1.66 cu. ft, of air per cubic foot of gas burned, and of this quantity of air 0.33 cu. ft. will pass into the products of combustion without giving up its oxygen. The products of combustion from burning 1 cu. ft. of this gas with 25 per cent air excess would then contain 0.31 cu. ft. CO 2 , 0.22 cu. ft, H 2 O, 1.65 cu. ft. N, and 0.33 cu. ft. atmospheric air. 62. Heat carried away by products of combustion. The sum of the products of the weights or volumes by the respective gravimetric or volumetric specific heats of the constitu- ents of the products of combustion will be the amount of heat carried away per pound or cubic foot of the gas for each degree of temperature of the gases above the atmosphere. Thus, for the products of combustion calculated in the pre- ceding section: A BCD CO 2 ................... Six. 0265 = .0082 H 2 O ................... 22 X. 01 73 = .0038 N .................... 1.65X.0192 = .0317 Air excess .............. 33 X. 0191 = .0063 .0500 A Combustion product constituent. B Quantity of " A " per unit of gas. C Volumetric specific heat, column J, table 3, p. 51. D Heat units per degree of temperature. If the temperature of the combustion products were 300 degrees F., the heat carried away by the combustion products of 1 cu. ft. of gas with 25 per cent air excess would be 0.05 X 300 = 15. B. t. u. 63. Sensible heat loss of producer-gas. The number of pounds or cubic feet of the gas evolved per THERMAL AND PHYSICAL CALCULATIONS. 43 unit weight of fuel multiplied by the gravimetric or volumetric specific heat of the gas will give the heat units carried away as sensible heat in the gas per unit weight of fuel, for each degree of temperature of the gas above the atmosphere. For calcula- tions of specific heat, see 52. 64. Flame temperature. (See App., notes 8 and 9.) The resulting flame temperature of the combustion of any substance is found by dividing the number of heat units evolved, by the products of combustion multiplied by their respective specific heats. (See App., note 2.) Thus for producer-gas: Heat units evolved per cu. ft. CO 2 X.0265 + H 2 Ox.0173 + Nx.0192 = However, since in practical work there will always be an excess of air, this must be taken into account when calculating the temperature, thus* Heat units evolved per cu. ft. The volume of the products of combustion are to be calculated by the method given in 61. 65. Explosive mixtures. (B 163.) Since producer-gas is frequently used in gas engines, it will be desirable to understand the conditions under which explosion may take place. " Any combustible gas will combine completely with oxygen, (1) when the mixture contains the two gases in the proper proportion; (2) when the temperature and pressure of the mixture are within fixed limits." " One cubic foot of hydrogen requires half a cubic foot of oxy- gen for complete combustion, and the latter is furnished by 2.4 cu. ft. of air. A mixture of hydrogen with either oxygen or air in these proportions is termed explosive, because the combustion when once started spreads with so great rapidity throughout the whole mixture as to be called an explosion. " Explosive mixtures cease to be inflammable, (1) when there is a certain excess either of the gases, or of an inert gas present, and (2) by a reduction of pressure. Table 2 gives the explosive mixtures for several gases: 44 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. TABLE 2. COMBUSTIBLE GAS EXPLOSIVE MIXTURE AIR TO 1 VOL. GAS Hydrogen . 2.4 Carbon monoxide 2.4 Marsh gas 96 Olefiant gas 14.4 Acetylene . . 12. Coal gas 5.7 66. Calculation of moisture in air. The amount of moisture or water vapor carried or held by air depends on the degree of saturation of the latter. Table 11, p. 267, gives the weights of vapor in pounds for 1 cubic foot of saturated air at different temperatures. Table 12, p. 268, gives the relative humidity of air; for definitions see 7, 8, 9, and 10. To determine the amount of vapor in air, multiply the values given in column F of table 11, p. 267, by the relative humidity, found from table 12, for the corresponding temperature, and the result will be the weight in pounds of the moisture in 1 cubic foot of air or gas, at the given temperature. CHAPTER IV. COMMERCIAL GASES. 67. Definition of commercial gas. A commercial gas is not a definite compound and is always made up of a plurality of constituents, the number of the con- stituents and their proportion being dependent upon the method of manufacture and the nature of the raw fuel. Table 3, p. 51, gives the properties of these constituents, the object of this chapter being to show their general effect upon the various com- mercial gases and especially upon producer-gas; by co-ordinating these in their proper relation to one another, we thereby secure a basis for the extensive discussion of producer-gas in the follow- ing chapters. 68. Hydrogen. This is colorless, odorless, non-poisonous, and the lightest known substance. The effect of hydrogen in a commercial gas is to make it lighter, to increase the heating value, the amount of air required for combustion, and the heat loss in the products of combustion. It is very combustible, and hydrogen uniting with oxygen burns with a pale blue nearly non-luminous flame, producing water in the form of water vapor. The reaction is as follows : In the gas-producer it is formed as follows: Hydrogen is always a desirable constituent of a commercial gas on account of its high calorific power and its avidity for com- bustion; however, as it will not stand much compression without danger of self-ignition, the amount that may be present in pro- ducer-gas, when the latter is to be successfully used in a gas engine, is limited. 45 46 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. 69. Marsh gas. It is sometimes called methane, and is the main constituent of natural gas and "fire-damp" in coal mines. It has a high calorific power, is colorless, slightly soluble in water, odorless, and burns readily with a slightly luminous flame. However, the rate of combustion is much slower than that of hydrogen or carbonic oxide, which makes it a very desirable constituent of producer-gas, especially when the latter is to be used in gas engines, as the presence of marsh gas decreases the danger of back-firing and pre-ignition by retarding the rate of combustion. It is produced by the decomposition of vegetable matter under restricted access of oxygen. It is also one of the products of the destructive distillation of coal. When it burns, the follow- ing reaction takes place: 70. Olefiant gas. This is sometimes called ethylene or ethene, and is the main illuminating constituent of coal gas. It is evolved when oil or coal is heated. It has a very high calorific p'ower, is odorless, colorless, and burns with a highly luminous flame, having four- teen times the luminosity of marsh gas. On complete combus- tion, the following reaction takes place: C 2 H 4 + 6O = 2CO 2 + 2H 2 71. Carbonic oxide. This is also known as carbon monoxide and is one of the most important constituents of producer-gas. It is odorless, color- less, practically insoluble in water, very poisonous (see 339), and burns with a distinctive pale blue flame, The reaction is as follows: It is formed by bringing carbon dioxide in contact with incan- descent carbon, the reaction being exothermic and taking place as follows: 72. Carbon dioxide. It is also called carbonic acid and carbonic anhydride. It is colorless, odorless, soluble in water (see table 20, p. 275), non- COMMERCIAL GASES. 47 combustible, and is formed by the complete combustion of car- bon and oxygen at high temperature. Thus: For an extended discussion of the effects of carbon dioxide on producer-gas, see Chapter 9. 73. Oxygen. This is tasteless, odorless, invisible, and slightly heavier than air. Its presence in a fuel gas is indicative either of leakage after the gas has been cooled or of improper action in the gas- producer, since it could not pass through a gas-producer in normal condition without combining with the combustible gas. 74. Nitrogen. This is a colorless, odorless, non-combustible gas and is always present in large quantity in gases produced by incomplete com- bustion, as in producer-gas, for instance. It has no influence except to act as a diluent. It forms four-fifths of the volume of air. 75. Hydrocarbons. The number of known hydrocarbons is nearly two hundred. The term is applied to all compounds consisting only of hydro- gen and carbon. These compounds exist in gaseous, vaporous, liquid, and solid states. Their character depends in a large measure on the temperature at which the reactions take place. Low temperatures are conducive to the formation of the easily condensed tarry compounds, while with high. temperatures the yield of hydrogen and permanent gases is greatly increased. (See. 106, and Chapter 23.) 76. Water vapor. As the vaporization of the moisture in, and the destructive distillation of, the fuel always produce steam or water vapor, it is nearly always found in producer-gas. Above the boiling point corresponding to the pressure of the gas, all the water will be in the vaporous state; below this point, part of the steam will condense, but a certain amount of water will always remain in the gas. Water vapor, on account of its high specific heat, may cause a large heat loss in the products of combustion. For the determination of the amount of water vapor in a gas, see 331. 48 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. 77. Air. This consists of a mixture of oxygen and nitrogen with very small quantities of other substances, such as argon, ammonia, carbon dioxide, and water vapor, the amount of the latter depend- ing upon the temperature and relative humidity of the atmos- phere. The method of calculating this will be found in 66. The amounts of argon, ammonia, and carbon dioxide are so small that they need never be considered. Pure dry air is composed of 20.91 parts and 79.09 parts N by volume, or 23.15 parts O and 76.85 parts N by weight. Ratio of N toO: By volume, |j|p3.77. By weight, |j|f = 3.32 Ratio of air to O: 1 QQ i nn By volume, ^j = 4-78. By weight, ^^ = 4.315 Ratio of air to N: By volume, J55L-1.265. By weight, ^ = 1.302 78. Illuminants. In a gas analysis, part of the constituents are sometimes men- tioned as " illuminants," the term "illuminant" meaning a sub- stance that makes the gas flame luminous, and olefiant gas is sometimes included with this. The percentage present in producer- gas is usually very small. 79. Natural gas. Natural gas is made by a secret process of nature, the principal constituent being marsh gas and the exact composition varying considerably with the different districts. While an ideal fuel, it is commercially available in only a few localities, and even there the uncertainty of the continuity of the supply makes its use uncertain. 80. Oil gas. This is made from oil, generally by allowing the liquid to flow slowly and in a thin, continuous stream through a highly heated pipe or retort, where the oil is vaporized. This usually evolves hydrogen, marsh gas, and olefiant gas mixed with vapor, which will usually be condensed in the scrubbing apparatus. COMMERCIAL GASES. 49 81. Coal gas. It is also called "bench" or "illuminating" gas; the former refers to the benches which hold the retorts, while the latter is dubious, since several other gases are distributed as illuminating gas. Coal gas is made by the destructive distillation of bitumi- nous coal in externally heated, air-tight retorts. The resulting gas is withdrawn by an exhauster and the residual coke is re- moved periodically. 82. Coke-oven gas. This is a gas made in a by-product coke oven; that is, the gas, tar, and ammonia evolved by distilling coal in a closed oven are saved and used as a by-product. Its composition is quite similar to coal gas. (See Chapter 19.) 83. Water gas. This is produced by the decomposition of steam when the steam acts on incandescent carbon. This reaction is discussed in de- tail in 117. As this reaction is endothermic (see 34), the tem- perature of the carbon will soon be reduced to a point where the reaction cannot take place, and it will then become necessary to store more heat in the carbon. This is almost universally done by shutting off the steam and blowing the carbon with air, thus bringing it back to incandescence and making it ready for the next steaming: this makes the system intermittent. On account of the large amount of carbon monoxide present, the gas is very poisonous. (See 339.) 84. Carbureted water gas. To change the blue flame of water gas to one that will be lu- minous, various methods are in use for injecting hydrocarbons as naphtha or oil into the gas and making it luminous. The resulting mixture is known as carbureted water gas; a large portion of the illuminating gas sold in this country is carbureted water gas. 85. Comparison of the commercial gases. The relative properties of the several commercial gases de- scribed, and the relation that these sustain to producer-gas, is shown in table 4, p. 50, which was compiled by Gow. This also shows the relation that blast-furnace gas sustains to the other commercial gases. The blast furnace is a huge gas-producer, and the resulting gas is very closely allied to producer-gas. 50 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. 86. Tabulated data. Table 3 gives a summary of the properties and data on the combustion of the constituents of commercial gases. The values TABLE 4. COMMERCIAL GASES. Names H CH, CzKU N CO CO 2 B. t. u. in 1 cu. ft. ex- plosive mixture B. t. u. cu. ft. Ore- quired for com- bustion Air for combus- tion Natural gas (Pitts- burg) 3.0 92.0 3.0 2.0 91.0 978. 1.94 9.73 Oil gas 32.0 48.0 16.5 3.0 0.5 93.0 846. 1.61 8.07 Coal or bench gas 46.0 40.0 5.0 2.0 6.0 0.5 0.5 91.7 646. 1.21 6.05 Coke-oven gas 50.0 36.0 4.0 2.0 6.0 0.5 1.5 91.0 603. 1.12 5.60 Carbureted water gas 40.0 25.0 8.5 4.0 19.0 0.5 3.0 92.0 575. 1.05 5.25 Water gas 48.0 2.0 5.5 38.0 0.5 6.0 88.0 295. 0.47 2.35 Producer-gas from hard coal 20.0 49.5 25.0 0.5 5.0 68.0 144. 0.22 1.12 Producer-gas from soft coal 10.0 3.0 0.5 58.0 23.0 0.5 5.0 65.5 144. 0.24 1.20 Producer-gas from coke 10.0 56.0 29.0 0.5 4.5 63.0 125. 0.19 0.98 Blast-furnace gas 1.0| 60.0 27.5J |11.5 91. .143 .72 given in column E are only approximate, but are close enough for all engineering calculations. The exact values are as follows: H. = l; CH< = 7.99; C 2 H 4 = 13.97; CO = 13.97; N = 14.01; O = 15.96; CO 2 = 21.95. Columns F, G. and I are taken from the Smith- sonian Physical Tables. -5 K is calculated by the method given in M and N are calculated by the method given in 56. = 4.32XM. (See 60.) P = 4.782 XN. (See 60.) Q. These values have been determined by various experimenters. . S is taken from Poole's Calorific Power of Fuels. COMMERCIAL GASES. 51 TABLE 3. CONSTITUENTS OF COMMERCIAL GASES. COMBUSTION DATA ;| t if EH i (N -f- OO Sp^tlg 3-1 QO " QO Kooodo NOTE. All calculations with the exception of those for steam are made on a basis of 32 F. and 29.92 in. i d, co" (M -3n 3 c3 .^ 3 3 "^ CO O CO CO vj-qi T o> BO O CO CO O o 10 1^ t^. oo 1 y jo '^j 'no i PH to 10 i> oq oo TF Tj5 l-H IO t>I T^ (>] CO rH r- 1 , 1 |||l y jo -^j -no i fr o oo o cO CO (N QO rti T-H , i co -* 1 2 D Evolved in formation of CO E In calorific power of gas F Absorbed in decomposing steam . . G Lost in ashes H Lost in unburned carbon I Lost in tar and soot J Lost in volatilization of hydrocar- bons K Lost in sensible heat of gas L Lost in heating undecomposed steam M Lost in evaporating moisture in coal N Lost in radiation P . . total sum of credits i.e. (A+B+C) A, the calorific power of the fuel, is that found experimentally by means of a reliable . calorimeter. B Let T = temperature F. of air as it enters producer. W = pounds air supplied per pound of fuel. (T-32) WX 0.237 = heat carried in by air blast. C Let Ti = temperature F. of the steam as it enters the pro- ducer. Wi = pounds of steam used per pound of fuel. X = quality of steam. h =heat of the liquid = 7\- 32. L = latent heat corresponding to T\. Q = total heat in 1 Ib. of steam from 32 degrees. Q = XL + h. C =TPi (XL + h). D = lb. carbon as CO 2 (per Ib. of fuel) 14,500. E =lb. carbon as CO (per Ib. of fuel) 4450. F = the calorific power of the gas found by the method of 53 and 33. G In 117, it was shown that 35,220 B. t. u. were absorbed in decomposing one pound of hydrogen. As one pound of steam is composed of -J pound hydrogen and f pound oxygen (see 47), the decomposition of one pound of steam will absorb 35,220 = 3913 B. t. u. 9 G = \b. of steam decomposed (per Ib. of fuel) 3913. 92 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. H Let W 2 = weight of ashes (dry). T 2 = temperature of ashes. .16 = specific heat of ashes. #=TF 2 (7^-32) 0.16 I Let y= grate efficiency of producer. 100 y = per cent of unburned carbon. (100 y) A = heat loss in unburned carbon. .7 Calculate the weight of carbon in the tar and soot per unit volume (cu. ft.) of gas and take its calorific power at 14,500 B. t. u. Let Z = weight of carbon from tar and soot per cu. ft. of gas. J =Z (number cu. ft. of gas per Ib. of fuel) 14,500. K Bell gives this to be 600 calories per kilogram of coal, or 1082 B. t. u. per pound of coal. This figure is not very reliable, but for want of a more exact value it is given here. L Let V = volume of gas in cu. ft. per pound of fuel calcu- lated by the method given in 55. S = specific heat of gas calculated by the method given in 52. T 3 = temperature of escaping gases. L=V (T 3 32) S = sensible heat carried out by gas. M Let TFm = per cent of moisture in fuel. W\ =lb. of steam used per Ib. of fuel. Wd =lb. of steam decomposed per Ib. of fuel. W n =lb. of undecomposed steam per Ib. of fuel. W v =lb. of moisture in gas per Ib. of fuel. The moisture carried in by the air may be neglected, as it will be very small. Wi + W m = Wd + W v W\ +Wm-W v =Wd Wl -Wd = W n Wi to be found by the method of 324. W v to be found by the method of 331. Wmto be found from fuel analysis. T 3 = temperature of escaping gases. T t = temperature of steam. M =W n (T 3 -T 4 ) 0.475 N Evaporation of moisture in fuel and heating of resultant steam. HEAT BALANCE OF THE GAS-PRODUCER. 93 Let W m = per cent of moisture in fuel. T 3 = temperature of escaping gases, (212-32) W m = E. t. u. required in heating from 32 to 212, 966 Wm = B. t. u. required in latent heat of evaporation. (T 3 212) 0.475 W m = R. t. u. required in heating steam from 212 degrees to T 3 degrees. #= total heat req. = (212-32) TF w + 966 W m + (!F S -212) 0.475 W m = W m [180 + 966 + (T 3 -212) 0.475.] P = radiation loss; since this is the only unknown, it may be found by difference. Thus, = P. CHAPTER XIL FUEL, 150. Early fuels. Coke and charcoal were the fuels used in the earliest forms of gas-producers, and they are still used where the gas is to be used in gas engines. The cost of these is too high for ordinary use and cheaper fuels must be used in most cases. 151. Character of fuel. A thorough and comprehensive knowledge of the kind and character of fuel to be used is a primary necessity. Since fuel varies so much in different sections of the country, great care should be exercised in its purchase; however, there is nothing that is bought so carelessly by the ordinary fuel user. Fuel is seldom sold on analysis or on a guarantee of its heating value, and when analyses are furnished by the seller, they rarely repre- sent a fair average. A knowledge of the adaptability of a fuel to the particular type of producer in which it is to be used is im- perative, since a producer that would give excellent results with one kind of fuel might fail completely in handling another kind. If the gas is to be used in gas engines or for many kinds of metal- lurgical work, the amount of sulphur in the fuel must be very low. 152. Condition. Coal should be used fresh, or carefully stored under cover to prevent the atmospheric distillation of the volatile matter, and it will always be found poor economy to use coal that has been stored outside and subjected to climatic changes. When used it should be as dry as possible at the time of its manufacture into gas, for two reasons: First, to prevent the loss of the heat, which otherwise would be required to evaporate the moisture. Second, to prevent con- densation or chemical combination of the moisture in the flue, which would precipitate the heavy hydrocarbons. Where wood is used it should be thoroughly air dried, thus 1 See App., note 12. 94 FUEL. 95 relieving the producer of the evaporation of the large amount of moisture that all green wood contains. 153. Size of fuel. The coal should be as nearly as possible uniform in size, as this will make level fires which burn evenly; fine dust should not be used, as it will obstruct the passage of the blast through the fuel bed. Neither should large lumps be allowed, as they will require longer burning than surrounding material and this causes irregu- lar combustion, some parts of the fuel being at a white heat, while large masses will hardly be heated through. Air and steam soon force their way through these weak spots and escape into the gas space above, burning both coal and gas. With the use of coal having no extremely large lumps, the repairs and de- lays, as well as operating expenses of the gas-producer, are greatly lessened, and the reliability and capacity of the plant are greatly increased. Large or crooked sticks of wood should never be placed in the producer, and the sizes of all pieces should be such as to form a compact and uniform bed in producer. 154. Coal. If this is used, it should be of good quality, rich in hydrogen, and ought to have a low percentage of ash, which should not clinker or run together under the influence of heat. Coals which become pasty when heated should not be used, as they will always give trouble in the producer. Local and commercial conditions will determine whether anthracite or bituminous coal is the less expensive in first cost, but the type of producer that is to gasify the coal and the use of the resulting gas will be the final criterion in deciding which coal is the cheaper. 155. Peat and lignite. (B 308, B 156, B 146.) The two principal difficulties in the use of peat and lignite are the large amounts of moisture present and the resistance offered to the passage of gas by the layer of fuel. On account of the latter point it is not ordinarily feasible to gasify these fuels in a suction producer, but a pressure gas-producer should be used that is capable of furnishing a higher pressure than is usually used. These fuels have been used extensively in Europe, and in many cases the gas has been used in gas engines. It would be very desirable to have the producer so arranged 96 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. that the gases pre-heat the fuel before it goes on to the fuel bed proper. This would remove a large amount of the moisture in the fuel, cool the gas, and thus conserve the sensible heat loss and also condense a large amount of the tar carried by the gas. The producer should be so arranged as to carry this condensed tar down into the incandescent fuel and thus break the former up into stable compounds. It is not generally advisable to use a coke scrubber with the usual type of lignite and peat producer, since the coke soon fills up with tar; a simple tower provided with a thorough spraying and sprinkling device is used in place of the coke. If the gas- producer were built on the lines suggested in the preceding para- graph, the tar would be held in the producer and the problem of scrubbing would then be much simpler. 156. Brown coal (B 226, B 182, B 177.) Brown coal in the form of briquettes has been used to a limited extent in Germany. Operating producers there with brown-coal briquettes proves in many cases more convenient than the use of anthracite. There is almost an entire absence of slag, and the fuel bed may be readily cleaned. The fuel bed holds the fire very well and when once blown up it may be restarted with ease. The coal in the form of briquettes is clean, easy to handle and to store; several plants are now in successful operation where the gas is used in gas engines. 157. Refuse. (B 325, B 328, B 310.) Shavings, sawdust, straw, bark, and similar refuse have been successfully gasified in the Riche gas-producer. (See 264.) CHAPTER XIII. REQUIREMENTS OF GAS-PRODUCERS. 158. Adaptability. The adaptability of the gas-producer to the work it has to do is one of its most important requirements. The use and com- position of the gas, nature of fuel, method of operation, economy required, and type of producer all are factors that must be co-ordinated in their proper relation, in order to secure a satis- factory producer-gas plant. The proper appreciation of this requirement, in its broadest sense, by designers and prospective users of gas-producers is imperative in order to insure the exten- sive development of the gas-producer in America. (See 87 and 270.) 159. Construction of producer. It should be compact and simple. Parts which wear or burn out rapidly should be made interchangeable and easily renewable. Proper provision must be made for cleaning all parts of the apparatus. 160. Composition of gas. This will depend on the nature of fuel, method of operating producer, and use of gas. In all cases, the amount of diluents should be kept as low as possible. For use in engines, the gas must be free from dirt, tar, or condensible constituents. When the gas is to be used in heating furnaces, it is not necessary to clean it, but a higher heating value is usually desirable than is necessary for engine use. 161. Automatic feeding. This will always be desirable and should always be used ; it may be accomplished by mechanical means as described in 200, or by gravity as shown in Fig. 70. 162. Continuity of operation. In all cases it will be desirable to have the producer able to 97 98 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. give continuous service; in fact, for some classes of work, conti- nuity of operation is of the utmost importance. The factors which have the greatest bearing on this requirement are auto- matic feeding, agitation of fuel bed, and removal of ashes. 163. Agitation of fuel bed. Mechanical pokers or revolving, swinging, or shaking grates are desirable to reduce the manual labor in operating the producer. Any one of the above devices is also conducive to continuity of operation. 164. Removal of ashes. For the continuous and satisfactory operation of the producer, it must be so arranged that the ashes may be removed without interfering with the process of gasification. 165. Deep fuel bed. The fuel bed should have considerable depth to insure com- plete gasification and a uniform quality of gas. In the suction type of gas-producer, where the blast velocity is low, the depth of fuel bed must not be too great; otherwise the negative w r ork of drawing the air and steam through the fuel will become ex- cessive. (See 273.) A low-blast velocity necessitates a shallower fuel bed and vice versa. With high-blast velocity, a deep fuel bed prevents the formation of least resistance channels for the blast, which would result in localized high temperatures and a higher percentage of CO 2 in the gas. 166. Introduction of blast. The steam and air should be introduced together, as they will then be more thoroughly mixed. They should be introduced at such a place and in such a manner as to secure a uniform distribution through the fuel bed. The zone of highest tempera- ture should be kept away from the grates and walls of the pro- ducer, thus preventing the "burning out" of the former and the fusing of clinkers to the latter. Neither should the blast form channels in the fuel bed. 167. Cleanliness. The producer should be so built that the fuel may be intro- duced without spilling and the ashes removed without difficulty. All joints must be made tight to prevent leakage of the gas into the producer room. This is of more importance with the pressure REQUIREMENTS OF GAS-PRODUCERS. 99 type than with the suction type of producer. In case of leakage with the former, the gas will be forced into the producer room and thus vitiate the atmosphere; in the latter case, air will simply be drawn into the producer. (See Chapter 28.) 168. Ease in starting. With producers used for power purposes, it is important that the producer may be easily started after a period of idleness. To do this, it is necessary to have the producer so constructed that it may be kept air-tight during the hours of idleness. 169. Regulation of steam and air. In all suction gas-producers, it is imperative that the propor- tion of steam and air be kept constant, although the load may fluctuate through a large range ( 208). 170. Heat insulation. To prevent undue loss by radiation, the producer must be sur- rounded by a proper non-conducting material. (See 27.) 171. Grate efficiency. The grate or fuel support must be designed with care and with special reference to the kind of fuel to be used. An inefficient grate may cause a serious loss of fuel in the producer. (See 139.) 172. Conservation of heat energy. The successful producer must utilize very little of the heat in the solid fuel in the process of gasification, and this is of special importance in producers used for power purposes. The fuel should be pre-heated by means of the sensible heat in the gas; this dries the fuel and cools the gas which is thereby made more desirable for use in an engine. The steam should be superheated and the air pre-heated; this may be done very nicely by utilizing the heat in the exhaust gases of the engine (see 214 and 216), and thus return to the producer about 10 per cent of the heat that would otherwise be wasted. With this arrangement a gas-producer will give over 90 per cent efficiency. CHAPTER XIV. HISTORY OF GAS-PRODUCERS. 173. Chronological record. The following chronological record gives the dates of the early development of the gas industry. 1669. Thomas Shirley conducted crude experiments with car- bureted hydrogen. 1691. Coal gas distilled by Dean Clayton. 1726. Stephen Hales in England pointed out that, by the dis- tillation of coal, an inflammable gas is evolved. 1788. British patent issued to Robert Gardiner for the appli- cation of waste heat of furnaces to raising steam, by passing the heated products of combustion under a boiler. 1791. John Barber took out a patent in England in which he proposed to use "inflammable air" for driving an en- gine and for metallurgical operations. 1792. Manufacture of coal gas introduced in England by Mur- dock. 1798. Lebon tried to make gas by the distillation of wood, but his apparatus was defective. 1801. Lampadius (B 10) proved the possibility of using the waste gases escaping in the carbonization of wood. 1804. Fourcroy mentioned the separation of hydrogen from water when the latter is brought in contact with white hot carbon. 1809. Aubertot (B 9) began to use the waste gases of blast fur- naces for roasting ores and burning lime. 1812. Aubertot (B 13) secured patent on furnaces for using waste gases of blast furnaces for roasting ores. 1814. Aubertot (B 9) suggested gas furnaces for general metal- lurgical work. 100 HISTORY OF GAS-PRODUCERS. 101 1814. Berthier published paper on waste gases (B 14). 1815. First oil gas-producer built and patented in England by J. Taylor. 1817. First application of the regenerative principle by Stirling. 1829. Neilson began the pre-heating of air for blast furnaces. 1830. Invention of first water-gas generator. 1830. Lampadius (B 16) tried to cupel silver lead by means of coal gas. 1831. British patent issued to James Slater for a method of utilizing waste heat. This is an ingenious application of the same principle to which, in a great measure, the modern regenerative gas furnace owes its success. 1833. British patent issued for the utilization of the waste heat from blast furnaces. 1834. In Jern-Kontoret's Annaler there is given a drawing of an apparatus for pre-heating the blast of a blast fur- nace by means of waste gas (B 8). 1836. Victor Sire, of Cleval, obtained a patent for the manu- facture of wrought iron by means of waste gases from a blast furnace (B 18). 1837. Wilhelm von Faber du Faur applied gases to puddling furnaces (B 9). 1837. Furnace for the use of pre-heated air designed by Slater. 1838. Ebelmen, Thomas, and Laurens (B 36) conducted experi- ments on the gasification of coal in France. 1839. Bischof experimented with the production of combustible gases by means of a separate producer (B 9). This producer is shown in Fig. 11. 1840. Austrian metallurgists attempt to produce combustible gases by the imperfect combustion of small charcoal (B 19). 1840. Ebelmen built a producer at the iron works of Audin- court in France (B 9). This is shown in Fig. 13. 1841. Karsten pointed out the advantages of the gas-producer for the utilization of low-grade fuels (B 9). 1842. Heine verified and amplified the deductions made by Karsten in 1841 (B 9). 1843. In Jern-Kontoret's Annaler there is a drawing of Ekman's method of pre-heating the blast by means of waste heat. 102 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. 1847. Regenerative furnace for the gasification of solid fuel followed by the burning of the gas in a chamber with air pre-heated by the products of combustion; designed and patented in England. 1850. Jern-Kontoret's Annaler contained drawings of Ekman's producer; this is shown in Fig. 15. 1856. British patent granted to Frederick Siemens for an im- proved gas-furnace. 1856. Beaufume producer tried by the French Government. 1857. Charles W. Siemens made improvements in gas-fired furnaces. 1858. Turner (B 22) in his " Eisenhuttenwessin in Schweden" published an extensive report of the workings of the Ekman gas furnace and gas-producer. 1859. (?). Wedding producer built in Berlin. 1861. Siemens gas-producer built. The advent of the Siemens type, which was the first producer that was commercially successful, was the real starting point of the modern gas-producer industry. There are still three impor- tant points in the development of the gas-producer : First, the introduction of the Dowson gas-producer in 1878, which was the starting point of the modern producer-gas power development; this was the first producer that was successful for power purposes. Second, the introduction of the Mond by-product process on a large scale in 1889. Third, the introduction of the Benier suc- tion gas-producer in 1895, which was the beginning of the use of gas-producers in small sizes and compact units. 174. Early use. (B 14, B 15, B 39, B 44.) (See App., note 13.) The employment of waste gases from iron furnaces or other metallurgical operations was one of the first steps in the develop- ment of gaseous fuel. The chronological record given in the pre- ceding section shows the dates of the early experiments. It is quite probable that the first producer was built by Bischof in 1839, and he was closely followed by Ebelmen in 1840, whose producer resembled a small blast furnace. The methods of both these men have formed the basis of nearly all the fuel-gas systems that have since been used; they consisted in the partial combus- tion of carbon by forcing a limited supply of air or a mixture HISTORY OF GAS-PRODUCERS. 103 of air and steam into a furnace containing the solid fuel in a state of combustion. 175. Conservatism in improvement. There is no piece of apparatus used in connection with modern industrial work that has undergone so few actual changes and real improvements until the last few years as the gas-producer. Until recently, one found in general use, with but few exceptions, the same form of producer as that originally constructed some sixty-six years ago a cupola-shaped furnace provided with some form of stationary grate or bed below, a hand-operated coaling hopper above, several poke holes at the top and possibly one at the side. Broadly speaking, the original type of Bischof and Ebelmen represented the larger part of recent practice. From the foregoing one might conclude that the producer has always given satisfaction and is ideal in its action. But experi- ence shows that this is not the case ; in many instances the pre- vailing form of producer has been very unsatisfactory, especially when fuel economy is considered. At present there are several industries demanding a better producer than most manufacturers are offering, the most important of which being the gas-engine industry. 176. Want of appreciation. While the production and utilization of gaseous fuel for indus- trial purposes were demonstrated in the earlier part of the last century, yet it is only within recent years that the value of the gas-producer is beginning to be appreciated and that the industry has received any impetus at all. Causes for this lack of appre- ciation are indicated in 88-90. 177. Bischof producer. This producer is shown in Fig. 11, which gives all the general dimensions of same. The central part or body of the furnace A, where the gases are generated, is cylindrical; the upper part B and the under part D are conical. R is a grate, underneath which is an ash pit E, closed by an iron plate F. An opening immedi- ately above the grate is arranged to be closed by an iron door G; S is a damper in the delivery flue. The throat of the producer is separated from the body by a damper C, and the top is closed by an iron lid P. The volume included between C and P is suf- ficient to hold one charge of the fuel with which the producer is 104 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. charged at intervals; by moving C, when P is closed, the charge of fuel can be introduced through the throat without any escape FIG. 11. BISCHOF PRODUCER. of gas. The air required for combustion enters through several apertures in the plate F; these are so arranged that their areas HISTORY OF GAS-PRODUCERS. 105 can be increased or diminished. The progress of combustion is under control by means of the damper and the apertures referred to, and can be observed through the holes 0, which, when not in use, are closed by brick stoppers. When the producer is working properly, its interior, as viewed through the lowest hole, should appear incandescent; at the middle hole the action should be less intense, and at the upper hole no signs of ignition should be visible. When the latter is not the case, there is much danger that the CO 2 will be excessive. In order to diminish this trouble, the fuel bed should be increased in thickness and possibly the amount of air should be decreased. No blast is used and the draft is produced by the furnace which the producer supplies. FIG. 12. EBELMEN GAS-PRODUCER. 178. Ebelmen's producers. (B 2, B 3, B 39, B 214.) Ebelmen designed, built, and operated three types of gas-pro- ducers at the iron works of Audincourt, France. The first of these is illustrated in Fig. 12, which shows the application of the producer to a puddling furnace. A is the ash chamber into which the blast is introduced; it then passes up through the grates B and into the fuel above. Steam is admitted at C. D is the charging hopper. E is the furnace in which the gas is burned, the air for combustion being pre-heated by 106 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. passing through the pipes G and then .introduced into the fur- nace at F. FIG. 13. EBELMEN PRODUCER. The blast-furnace type of producer is illustrated in Fig. 13. It is worked with a blast of air which enters at F. In general HISTORY OF GAS-PRODUCERS. 107 outline it resembles a small blast furnace. C is a cast-iron pipe which descends from the throat into the body of the furnace and which is kept constantly filled with fuel; at Audincourt the fuel was small charcoal. A lid is necessary only when large lumps of fuel are used, the small pieces offering sufficient resistance to the passage of the gases which find a free passage from the body of the furnace D, up and through B, and out into the flue A. E is the hearth of the furnace into which the blast is introduced. About 1J parts by volume of iron-furnace slag and clay are FIG. 14. EBELMEN GAS-PRODUCER. charged into the furnace with every 100 parts of combustible; this forms an easily fusible slag with the ash, which can then be run off from the bottom of the hearth, E. In the operation of this producer, the condensation of the tarry vapors in the flue A was a source of constant trouble when uncharred fuel was used in the producer. The down-draft type of producer is illustrated in Fig. 14. A is the main chamber of the producer; this is connected with B by 108 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. means of C. Raw or fresh fuel is delivered to A, and B is filled with incandescent carbon. The blast is admitted at D, passes FIG. 15. EKMAN PRODUCER. through C and up through B; in this way the air is drawn down through the fuel in A. E is the lid for the chamber A and is HISTORY OF GAS-PRODUCERS. 109 fitted with an arrangement to regulate the amount of air passing through. The object of this type of producer was to break up FIG. 16. BEAUFUME PRODUCER. the tar and other hydrocarbons in the gas. The original draw- ings show a small blast pipe at F, and it is quite probable that 110 A TREATISE ON PRODUCFR-GAS AND GAS-PRODUCERS. steam was introduced at this point, although no mention is made of it in the original description. ' / '/////////////////////////// A//// ///////////// FIG. 17. WEDDING PRODUCER. 179. Ekman producer. (B 15.) This producer was designed by Gustaf Ekman and was used at the Ekman Iron Works in Sweden for reheating slabs of iron. HISTORY OF GAS-PRODUCERS. Ill Its construction is shown in Fig. 15. D is the body of the pro- ducer into which the fuel is charged by means of hopper A and sliding damper B. C is a lever for operating B. The inside of the producer is lined with firebrick and the body of the producer is inclosed within a cast-iron jacket; a free annular space is left between them. The blast enters at F and then passes into the producer through the tuyeres E; the object of the annular space H is to pre-heat the blast and also to reduce the radiation loss. The interior of the producer could be examined by removing the plugs G. K is the ash pit, the ashes being removed by means of the door J. The object of the ledge I is to prevent the entire mass of fuel from falling or sliding down while the ashes are being removed. L is the flue leading to the furnace where the pro- ducer-gas is burned. Wood charcoal was the fuel used in this producer. 180. Beaufume producer. (B 8, B 9, B 39.) This producer was tried by the French Government at the Imperial Arsenal at Cherbourg, and it is shown in Fig. 16. A is the cover to the charging hopper. C is a bell which is connected to a counterweight by means of link B. E is the flue leading to the furnace and D is a pipe communicating with the atmosphere. G is the fuel bed, which is about 24 inches deep, and this is sup- ported on the grate bars H. The blast enters the ash pit / through pipe /, then passes up through the fuel into the space F, then out into E. The entire producer is surrounded by the water jacket. 181. Wedding producer. (B 15.) This producer was in use at the Mint tmd Royal Porcelain Manufactory at Berlin prior to 1861. (See preface to Percy's Metallurgy, vol. on Fuel, also p. 517 therein.) It is shown in Fig. 17. A is the door to the charging chamber B. The fuel is dropped into the body of the producer F by means of the sliding damper C, which is operated by handle D. E is the flue leading to the furnace. G and H are grate bars. I and J are doors for gaining access to the ash-pit L. K is a pipe through which the blast enters. 182. Siemens producer. This is shown in Fig. 18. A is a self-closing hopper for charg- ing the producer with fuel. B is the apron wall composed of brick resting on a cast-iron plate C. D is a grate composed of 112 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. horizontal flat bars. E is an opening for cleaning or poking the fire or testing the gas. F is a cleaning and explosion door. The gas leaves the producer through the brick uptake G, iron- cooling tube H, and iron downtake /; it then goes to the furnace through the flue J. K is a tar well that catches the tar con- densed in the tube. The action of the cooling tube is as follows: The temperature of the gas as it leaves the producer is about 400 degrees C.; this is cooled to about 100 degrees C., thus decreas- FIG. 18. SIEMENS GAS-PRODUCER. ing the volume and increasing the density of the gas, thereby making the volume of gas in 7 heavier than that in G. As a re- sult, a current is produced in the direction of the arrows, and a draft is established in the producer. The cooling tube is a very cumbersome means for inducing the draft in the producer, and this now is always dispensed with and a positive blast is introduced in the ash pit, which is enclosed. CHAPTER XV. AMERICAN PRESSURE GAS-PRODUCERS. 183. Taylor -fluxing gas-producer. (B 24.) This producer was designed about 1878 by Mr. W. J. Taylor, for use in his ore-roasting kilns at Chester, N. J. It has the general lines of a blast furnace, with the following dimensions: The hearth is 24 in. diameter and 24 in. high. The bosh wall makes an angle of 25 degrees from the vertical, and enlarges to 4 ft. diameter; then it is drawn in to 3 ft. at the top, the total height being 12 ft. The blast enters through a IJ-in. nozzle which is placed in a water-coil tuyere 12 in. above the bottom. The blast is produced by a small Weimer blowing engine which furnishes 300 cu. ft. of air per minute at a pressure of 1J Ib. per square inch. The producer consumes about 200 Ib. of coal per hour and 1J h. p. is required to blow it. The ashes are fluxed out about every two hours. Cinders and limestone are charged in with the coal and thus act as fluxes. The advantages claimed for this producer were: (1) Uniform quality of gas and low per cent of C0 2 . (2) There was no cleaning of ashes; the producer was kept in continuous operation for at least four weeks. (3) The quantity of gas from this producer could be increased by simply increasing the amount of air entering it. 184. Langdon gas-producer. (B 35.) This producer is shown in Fig. 19, and it was designed for use at the Taylor ore-roasting furnace at Chester, N. J. The producer is built on the general lines of a blast furnace, and consists essen- tially of a cylindrical furnace, enclosed in an iron jacket or casing, having a bosh or inverted cone-shaped base. The fuel is charged in through the bell and hopper at the top. The producer is cleaned by means of the small door placed at the hearth level, 113 114 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. which, in order to facilitate cleaning, is elevated above the floor. The door can be removed, and when closed is held tightly against its frame by means of lugs. FIG. 19. SECTION OF LANGDON GAS-PRODUCER. The blast is furnished by air and steam which is injected into the fuel through a series of tuyeres underneath the bosh. A small flue also connects the door passages with the blast pipe, and a portion of the blast entering in this way prevents the doors AMERICAN PRESSURE GAS-PRODUCERS. 115 FIG. 20. SECTION OF FUEL GAS AND ELECTRIC ENGIN- EERING Co. ; s GAS-PRODUCER. 116 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. from becoming warped and overheated. The gases pass off through the flue at one side near the top. In cleaning, the fuel in the upper part of the producer is held by the sloping walls of the bosh while the ash below is removed. Anthracite and bituminous coal and coke dust have been used successfully in this producer. 185. Fuel Gas and Electric Engineering Co., Ltd., Producer. This producer is shown in Fig. 20; it was used by the above company for the manufacture of fuel gas. Fig. 20 represents a vertical section. The shell is 20 ft. high, 9 ft. outside diameter, and the diameter inside the lining is 6 ft. The producer has large cleaning and ash-pit doors on both sides- opposite each other in order to facilitate cleaning. In order to get a gas low in carbonic acid, a much larger depth of fuel was used. As it would be impossible to poke such a deep fire by hand, a pneumatic rammer was placed upon the producer. This rammer consists of a cast-iron ring, so constructed that it will not only exert a pressure upon the coal but also force the coal to the periphery of the producer, which is desired because the gas has a tendency to creep up along the walls. The ring is raised by air pressure and allowed to fall upon the fuel, the stroke given depending upon the blow necessary to make the fuel sink regularly. Steam is admitted under the grate, and both air and steam are controlled by valves from the top of the producer. This producer gasified from 12 to 15 tons of coal in 24 hours. The carbonic acid in the gas was sometimes as low as 1.4 per cent. The following is an analysis of the gas, at a pressure of four inches of water: CO 2 3 4% CH 4 . 3 1% H 9.2% C 2 H 4 8% CO.. ..23 .3% The remainder was mainly nitrogen. 186. Kitson gas-producer. (B 90, B 131.) This producer is shown in Fig. 21. The grate is connected on one side with a steam and air injector; on the other, with the AMERICAN PRESSURE GAS-PRODUCERS. 117 gas-supply pipe, which runs to the place of consumption and is surrounded by a cast-iron box securely attached to the cylindrical FIG. 21. SECTION OF KITSON GAS-PRODUCER. shell, forming the ash pit. The whole machine is supported on four cast-iron legs. 118 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. The ash box terminates in a mouthpiece which is opened and closed with a valve operated by a lever from the outside; the mouthpiece thus serves to dump the ashes, whenever desirable, without interfering with the process of making the gas. A small reservoir forming the boiler is placed on one side and communi- cating therewith are two coils contained in the brickwork. The lower coil heats the water and furnishes steam, and the upper coil superheats it. Air channels are arranged spirally in the brickwork, through which air is drawn by the injectors. The air thus becomes heated before mixing with the steam, which must be thoroughly dry. The grate is provided with a mechanism for giving it a rotary and up-and-down motion, the effect of which is to break up any clinker that may have adhered to the sides of the furnace, to keep the coal in a compact mass, avoiding holes in the fuel, and to throw the dust and ash into the ash pit. The coking with soft coal is effectively broken up, and the steam finds an easy passage through it. The following is an explanation of Fig. 21: A ash pit, B fire- brick hearth or grate, C air-passage ways for heating air supplied to injectors, D injector pipes leading to center of grate, E and H screw and hub for giving grate the rotary and up-and-down motion, F furnace, G vertical grate bars, / steam boiler, J hot- water coils connecting with boiler, K superheating steam coils communicating with boiler, L dust valve, M injectors, N hopper to supply coal to furnace, 0, P, Q mechanism for rotating grate, R gas take-off pipe, S water seal, T butterfly valve for dumping ashes. 187. American Furnace and Machine Co.'s producer. Fig. 22 is a vertical section on line CD. Fig. 23 is a vertical section on line AB. Fig. 24 is a horizontal section on line EF. The producer consists of a cylindrical body with charging hopper above, sloping grates and water-sealed ash pit below. Two blowers are used for furnishing the blast, which is admitted under the grates as shown in Fig. 22. 188. Amsler gas-producer. The construction of this is shown in Fig. 25. A is the pro- ducer body with the usual charging hopper B and gas outlet C. D are poke holes for stirring the fuel in A. E is a steam blower AMERICAN PRESSURE GAS-PRODUCERS. 119 which drives the blast through F into G and up through cone H. I is the water-seal ash pit. 189. The Swindell gas-producer. The principal features of this producer are shown in Fig. 26, FIG. 22. AMERICAN FURNACE AND MACHINE Co.'s PRODUCER. FIG. 23. AMERICAN FURNACE AND MACHINE Co.'s PRODUCER. FIG. 24. AMERICAN FURNACE AND MACHINE Co.'s PRODUCER. which is a vertical section; Fig. 27, which is an elevation; and Fig. 28 ; which is a horizontal section. There are two sloping grates, 120 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. G, Fig. 26, located centrally, with a body of coal between them, so as to secure the full working capacity of the grate surfaces. FIG. 25. SECTION OF AMSLER GAS-PRODUCER. The starting and cleaning door C is located at the lowest point at the water-seal line. The water-seal pan AP has a width equal to that of the grates and a length equal to the diameter of the jacket. It is divided into two sections, so that the ashes may be AMERICAN PRESSURE GAS-PRODUCERS. 121 removed at both ends conveniently. The steam pipes S extend over the whole length of the grates and are so arranged that the current of steam is directed toward the center of the body of coal instead of toward the walls. This is done to avoid the for- mation of clinkers. The gas neck is located at the highest point of the chamber so that there is no dead space for the accumula- tion of gas. This gas neck has a cleaning stopper hole at the top and a cleaning door at its end. By shutting off the gas main by the damper plate SD, any producer of a battery in operation can be cleaned without stopping the operation. FIG. 26. SWINDELL GAS-PRODUCER. Two coal hoppers, H, are provided to effect an easy and even distribution of the coal over the whole area of the grates. The tongue of these hoppers is hollow at the back so as to avoid the over-heating and consequent warping which causes leaky joints. There are four ball poke holes in the roof and two stopper poke holes in the top plates of the hoppers, so that every part of the coal pile in the chamber is within easy reach of the operator. Since the gas chamber has a brick roof, the top of the producer is protected against excessive heat. 190. The Porter gas-producer. This producer is shown in Fig. 29. It consists, in the main, of a 122 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. DDDDDDDDDDDDDODO DDODDDGCDCDDDCDD AMERICAN PRESSURE GAS-PRODUCERS. 123 circular body A, with gas outlet B on the side, and a cast-iron plate containing the usual hopper C, and poke holes D on top. FIG. 29. SECTION OF FORTER-MILLER GAS-PRODUCER. The shell and lining are supported by four cast-iron columns E, which rest on the foundation of the producer. A conical ash 124 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. hopper F, made of heavy steel plates and calked air-tight, is suspended from the bottom of the shell and extends a few inches below top of ash pan, thus forming a water seal with the water contained in the pan. FIG. 30. SMYTHE GAS-PRODUCER. At its upper end, the ash hopper is provided with a wind box G adapted to receive grate sections H. A number of air-tight doors / are located in the wind box, through which the grate sections can be inserted or removed. These doors, when open, give access to the fuel bed through the grate sections, so that clinkers that might accumulate on the grates can easily be re- moved from the outside. A row of poke holes J, just above the wind box, give additional facilities for removing heavy clinkers. The air necessary for gasification and partial combustion is delivered into the wind box by steam blower K, and enters the fuel through the circumferential grates. A third steam blower L delivers air through a centrally located vertical pipe M, covered AMERICAN PRESSURE GAS-PRODUCERS. 125 with a cone-shaped hood N, to the center of the fuel bed. The fuel is supported on a bed of ashes which rests in a pan below the hopper. 191. Smythe gas-producer. The construction of this producer is shown in Fig. 30. It con- sists of a circular body A, charging hopper B, cast-iron top with poke holes C, gas exit D, and inclined grate E. The steam is introduced at a higher point than usual and acts directly on the incandescent mass of coal. 192. Duff gas-producer. The construction of this is shown in Fig. 31, which is a section FIG. 31. DUFF GAS-PRODUCER. on line AB; Fig. 32, which is a section on line CD; and Fig. 33, which is a section on line EF. The main features are embodied in the following patent claims, given verbatim: 1. "A gas-producer provided with a water-sealed bottom trough and a casing located in the lower portion of the producer provided with an inlet for air from the blower and with a cover of gratings inclined from the sides of the casing upward to a middle angular ridge, and free spaces between the said casing and the sides of the producer for the residues to pass from the gratings of the said casing to the water trough." 2. "A gas-producer of rectangular section provided with a water-sealed bottom trough and a transverse casing extending 126 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. from side to side of the producer across the center thereof, the said casing being provided with an inlet for air from the blower and with a cover having vertical openings therein, said cover being inclined upward from its opposite sides between the casing and the sides of the producer." 3. "A bottom casing or chamber into which a blast of air and steam is delivered; a top or cover for this casing or chamber consisting of outwardly inclined gratings having openings to dis- tribute the blast under the bed of the fuel and forming also guid- ing surfaces down which the residue ashes will slide towards the FIG. 32. DUFF GAS-PRODUCER. Section E F FIG. 33. DUFF GAS-PRODUCER. exterior of the producer, and free spaces between the lower edges of the inclined gratings and the walls of the producer through which the ashes will descend into the water trough which seals the bottom of the producer, and from which trough the removal of the ashes is effected without making any opening into the producer and without interruption of the air blast." 193. Taylor gas-producer. This producer was designed as a result of extensive experi- ments covering about twelve years, conducted by Mr. W. J. Taylor in connection with his ore-roasting kilns at Chester Furnace, N. J. It is shown in Fig. 34 and 35. The type illustrated in Fig. 35, with a revolving bottom and shell lined with firebrick, is that usually adopted for an- AMERICAN PRESSURE GAS-PRODUCERS. 127 thracite and a good quality of bituminous coal. For bitumi- nous coals liable to clinker, the design with the water jacket FIG. 34. SECTION OF TAYLOR GAS-PRODUCER. shown in Fig. 34 is used. The clinker will not adhere so readily to the smooth sides of the water jacket as to firebrick, and the 128 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. former is not liable to injury when poke bars are used from above. FIG. 35. SECTION OF TAYLOR GAS-PRODUCER. . The distinguishing features of the producer are as follows: The maintenance of a deep fuel bed carried on a deep bed of AMERICAN PRESSURE GAS-PRODUCERS. 129 ashes. Blast carried by conduit through the ashes to the incan- descent fuel. FIG. 36. SECTION OF WOOD DOUBLE-BOSH GAS-PRODUCER. The revolving bottom, the turning of which will produce a grinding action in the lower part of the fuel bed, and thus close up any channels that may have been formed by the blast, in this 130 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS way keeping the CO 2 in the gas low. A few turns of the crank at frequent intervals will keep the fuel bed solid. 194. Wood double-bosh gas-producer. This is shown in Fig. 36. The special feature is its double FIG. 37. SECTION OF WOOD WATER-SEAL GAS-PRODUCER. bosh. The air entering the blast pipe, which protrudes through the bosh plate, passes to the vertical central air conduit and cir- culates also about the inner boshes. These are perforated, per- AMERICAN PRESSURE GAS-PRODUCERS. 131 mitting the passage of the air into the ash bed, taking up its heat and insuring checking the escape of combustible matters in the ash. This type, equipped with the Bildt automatic feed as shown, has given excellent service with the lignite coals of the West. r\ FIG. 38. WOOD FLAT-GRATE GAS-PRODUCER, 195. Wood water-seal gas-producer. This is shown in Fig. 37, where A is the body of the producer, B the coal-feeding hopper, and C the gas exit. D is a steam 132 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. blower that forces the blast through and around the cone E. F are poke holes, and G is the water-seal ash pit. H are balanced poking bars, six being placed on the top of the producer. 196. Wood flat-grate gas-producer. The construction of this is shown in Fig. 38 and 39, the latter being a horizontal section through line AB of the former. 197. Wood single-bosh water-seal gas-producer. The construction of this is shown in Fig. 40. FIG. 39. SECTION OF WOOD FLAT- GRATE GAS-PRODUCER. 198. Wellman gas-producer. This is shown in Fig. 41. It is a modified form of the old Siemens type, with a steam blast attachment. It is intended primarily to be used in connection with a heating furnace. A is the body of the producer with charging hopper B and exit C. D is the grate over ash pit E. F is the blast pipe. 199. The Fraser-Talbot gas-producer. In the design and mode of operation this producer is radically different from any other type. In some cases rotary or revolving bottoms have been intro- duced with a view to facilitate the discharge of the ashes and to provide for a greater capacity for gasifying the coal ; the continued demand for a mechanical producer has led to the development of this type. The producer is shown in Fig. 42 and 43. It consists of a AMERICAN PRESSURE GAS-PRODUCERS. 133 cylindrical shell or casing riveted to four /-beam columns C, which rest upon foundations and support the shell and operating ^WJ&W^ FIG. 40. WOOD SINGLE-BOSH WATER-SEAL GAS-PRODUCER. machinery. It is not connected in any way to the building in which it is placed. To the lower part of the shell is attached a conical cast-iron fire pot D, the lower edge of which is covered 134 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. by water in a concrete ash pan E, therefore forming a water seal. In the center of this ash pan is a hollow cylindrical column F f terminating at its upper end in a cone. The annular space between the edge of the cone and the cylinder and the opening in the top cone, which is protected by the circular flange, form FIG. 41. WELLMAN GAS-PRODUCER. outlets for the blast, which is conveyed to the central column F by means of a circular inlet pipe G on one side of the producer. This inlet pipe is provided with a force blower, preferably of the injector type. The cone forms a bearing for the vertical water-cooled shaft H, to which are connected two water-cooled arms /, one arm being inclined at the angle shown and the other arm extending AMERICAN PRESSURE GAS-PRODUCERS. 135 in a horizontal direction and at right angles to the shaft. The combination of the shaft and the arms forms a mechanical stirrer or agitator. FIG. 42. SECTION OF FRASER-TALBOT GAS-PRODUCER. The shaft H has a combination of rotating and vertical motions, which are effected by means of gearing connecting the shaft to 136 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. an electric motor ,7. This motor and the gearing are carried on a steel platform riveted to the tops of the supporting columns FIG. 43. ELEVATION OF FRASER-TALBOT GAS-PRODUCER. C, and braced to them. The gearing for giving the shaft the rotary and vertical motions is of an exceptionally heavy design, AMERICAN PRESSURE GAS-PRODUCERS. 137 and in general consists of a train of spur gears reducing the mo- tion from the electric motors to a worm wheel, which is connected to the upper end of the shaft H by means of a feather and groove. The latter provide for the vertical motion of the shaft, which is effected by means of two cranks on a horizontal shaft directly over the vertical shaft. These cranks are connected to a cross head K by means of connecting rods L. The cross head is con- nected to the vertical shaft by means of two collars, between which is placed a powerful spiral spring. The arrangement of gearing is such that the vertical shaft has a slow rotating and vertical movement, and if at any time the shaft should become jammed against an excessively large and hard clinker the vertical motion will cease automatically until the arm which is in contact with the clinker moves through a segment of a circle past the clinker, when it will be forced down into its proper position by the spring. This allows a slight elasticity in the movement of the shaft and will prevent the breakage of the arm. , As a further safeguard, a slip clutch is placed on one of the gear wheels. In practice it is found that the combined rotary and vertical movements prevent the for- mation of any large and hard clinkers. The producer is fed through two hoppers as shown, or by means of a Bildt or any other approved form of feed. Among the advantages of this form of gas-producer is the doing away of the severe and continued labor of poking the fire, an operation which is extremely difficult to maintain in a steady and uniform manner. The poking being entirely mechanical, it is done in a thorough and proper manner without reference to any manual labor, and as a consequence the quality and quantity of gas should be much improved. 200. Morgan gas-producer. The construction of this producer equipped with the Bildt automatic 'feed is shown in Fig. 44, where A is a hopper into which the coal is primarily deposited, B is a register valve con- trolling the admission of coal to the tank C, directly below. D is a rotating distributing disk, having sloping sides of varying angles so designed as to deposit the coal evenly over the charg- ing area. The disk is rotated by the bevel gears E and a special ratchet motion F operating through the vertical shaft G. H is 138 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. a shallow annular pan for holding water which is used to seal the poke holes and the joint formed by the lower edge of tank base. FIG. 44. SECTION OF MORGAN GAS-PRODUCER EQUIPPED WITH BILDT AUTOMATIC FEED. The body of the producer is cylindrical in form, the walls being heavy to prevent undue loss from radiation of heat. / is a sub- AMERICAN PRESSURE GAS-PRODUCERS. 139 stantial cast-iron mantle, upon which the producer rests. The lower edge of the mantle dips into the water below, forming an effective seal. There are but four narrow points of support for the mantle, so that practically the whole circumference is unobstructed for the removal of ash. / is a steam blower, which is built with special view to regu- lating the proportion of air and steam going into the producer at any pressure. K is a cast-iron box forming a conduit through which the blast is enabled to reach the lowest possible point of the producer. L is a cap or hood which serves the double pur- pose of keeping ashes out of the blast box and of distributing the blast to a proper point under the fuel bed. The hood is circular in form, proportioned to the diameter of the producer. All of the blast is delivered from under the center of area of charging surface. Referring again to the feeding mechanism, the coal is supplied to the hopper by any convenient means and dropped into the coal tank C below as needed. The coal tank may be made large enough to receive any desired quantity of coal, but two or three hours' supply is usually deemed sufficient. The slow rotating motion of the distributer causes the coal to work out of the tank C and fall over the edge of the distributer. The speed of the distributer is from a fraction of 1 to 10 or 15 revolutions per hour. Speed adjustments are made by an adjustable guard moving under the ratchet pawl. Fig. 45 shows a Morgan producer fitted with the George auto- matic feed, and Fig. 46 shows the operating or charging floor of the Lackawanna Steel Co. at Buffalo, N. Y., where a large num- ber of these producers have been installed. 201. Loomis gas-producer. This is shown in Fig. 47. The producer is of the down-draft type and presents several unique features of design. A and B are two cylindrical producers connected at the top by the fire- brick-lined pipe F. E and D are valves connecting the producers with the economizer C, which is simply a vertical tubular boiler. G is a pipe connecting the economizer with the water-spray scrubber H. 7 is a pipe connecting H with the exhauster J, which is driven by engine K. L is a seal. M is a pipe leading to producer-gas holder. is a pipe connecting the producer with 140 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. the chimney. P is a cleaning door. R is the ash-pit door. Q is the charging door through which the coal is fed. S is a steam pipe leading from C to the ash pit of the producers. N leads to the water-gas holder. In starting the producers a layer of coke or wood and coal about five feet in depth is put in and ignited at the top, the ex- FIG. 45. SECTION OF MORGAN GAS-PRODUCER EQUIPPED WITH THE GEORGE AUTOMATIC FEED. hauster J creating a downward draft. When this body of fuel is ignited, coal is frequently charged, raising the fuel bed to about eight feet above the grates, and there maintained. Bitu- minous coal is generally used; this is delivered 'on the operating floor and fed through the doors Q, as needed. The air is also admitted through Q and by means of the ex- hauster J is drawn down through the fresh charge of coal and AMERICAN PRESSURE GAS-PRODUCERS. 141 142 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. then through the hot fuel bed underneath. The valves E and D being open, the producer-gas is drawn down through the grates and ash pits of producers A and B, then up through the economizer C, down G and up through H, down through / and J into L. It FIG. 47. LOOMIS GAS-PRODUCER. requires about ten minutes to start the producers ; during this time the gas will be too lean for use, and hence it is allowed to go to the chimney by means of a pipe 0. As soon as the producer is working properly, the valve in is closed and the valve in M opened, thus allowing the gas to go to the holder. AMERICAN PRESSURE GAS-PRODUCERS. 143 In making water gas the operation is as follows : When the exhauster has brought the fuel up into incandescence, the charg- ing doors Q are closed, valve D lowered and the valve in N opened, the valves in and M being closed. Steam is then turned on in B by means of S, and, in passing through the incan- descent coal, is decomposed, forming water gas. Water gas is made about five minutes; when the temperature of the fuel beds has been considerably reduced, the steam is shut off and pro- ducer-gas is made again. This process of making water and producer-gas is alternated at intervals of five minutes or more, according to the quality of gas desired. In making the next run of water gas the course of the steam is reversed; i.e., valve D is opened and valve N closed. FIG. 48. SECTION OF WILE AUTOMATIC GAS-PRODUCER. This type of producer has been used quite extensively for making gas for power purposes, and it has given very good re- sults. It is also guaranteed to make a gas clean enough for engine use from bituminous coal, and an economy of 1| Ib. of coal per brake-horse-power hour is the guarantee of the builders. 202. Wile automatic gas-producer. This is shown in section in Fig. 48, and Fig. 49 shows the general arrangement. It is a combination of a pressure and suction producer. The producer is under suction while the gas is delivered under pressure by means of a steam ejector, which sucks the gas from the producer and forces it through the 144 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. usual cooling and scrubbing apparatus into a regulating gas holder. Referring to Fig. 48, B is the ejector which sucks the gas from the producer and forces it through the scrubber and into the regulating holder or receiver. The latter has three pipes: a gas outlet to engine, a gas inlet, and a return pipe D which leads back to the seal box C and is provided at its top end with the valve F, carried by a lever arm which is arranged in the path of a projecting valve lifter E fixed to the gas belL AMERICAN PRESSURE GAS-PRODUCERS. 145 When the bell rises to its top position, the valve F is opened, and the ejector at B, instead of sucking gas from the producer, sucks it from the receiver and keeps it circulating through D until the bell drops enough to close F. As the producer is not under suction or in operation while the gas is in circulation, FIG. 50. WILE WATER-SEAL GAS-PRODUCER. the movement of the bell makes the operation of the producer automatic. 203. Wile water-seal gas-producer. The construction of this is shown in Fig. 50. The larger part of the blast enters the fuel bed in a lateral direction from the central cone. CHAPTER XVI. AMERICAN SUCTION GAS-PRODUCERS. 204. History of development. In 1884 C. Wiegand secured a patent on the idea of having the suction of the gas-engine piston draw air through the gas-pro- ducer and thus generate gas which in turn was used in the engine. On the investigation of several interested firms the idea was dropped and the patents allowed to lapse. However, Wiegand was very close to the successful solution of the problem, and failed only because he did not understand all of the require- ments. The first practical suction gas-producer was built in 1895 by Benier in France; this was not entirely successful, but the difficulties were primarily due to the inadaptability of the engine that was used with it. 205. Definition of suction gas-producer. The fact that a producer may be operated by an induced draft like the Loomis (Fig. 47), made by an exhauster, or that the blast is directed downward as in the inverted combustion type (Fig. 47), does not constitute a suction gas-producer. These terms have frequently been used incorrectly and indiscriminately. The term suction gas-producer must be applied only to those producers that have the air and steam drawn through the fuel bed by means of the exhausting action of the gas-engine piston on its charging stroke. Neither should the term "suction gas" be applied to the gas made in the " suction " type of gas-producer. (See 98.) 206. Classification. The suction gas-producers now on the market may be divided into three general classes, with reference to the position of the steam-generating apparatus : First, where the vaporizer is an integral part of the producer. Second, where the vapo'rizer is entirely separate from the producer. Third, where the vaporizer is not only separate but is heated by the engine exhaust. The 146 AMERICAN SUCTION GAS-PRODUCERS. 147 nomenclature of the steam-generating apparatus has not been uniform on account of the individual preferences of the various designers. The terms "boiler," "saturator," "vapor chamber," "steamer," "evaporator" and "vaporizer" have been used indiscriminately; the last term is the best. 207. Operation of suction gas-producers. The reactions by which the gas is evolved are not novel and are the same as those taking place in a pressure gas-producer as dis- cussed in detail in Chapter 7. For data on the handling of a suction gas-producer plant see Chapter 25. 208. Steam supply and regulation. The accurate regulation of the amount of steam fed into the producer is of great importance, especially if the load on the engine is variable. The quantity of steam going into the producer must always be proportional to the amount of gas that the engine is using, regardless whether that amount is fixed and uniform or variable. If the normal amount of steam required at full load is allowed to go into the producer when the engine is running light, not only will the composition of the gas be changed very materi- ally and cause trouble in exploding, but the fire in the producer will be extinguished in a very short time. However, when the engine is working at full load, a maximum amount of steam is necessary to avoid excessive temperature of the fire and the formation of clinkers. In order that a suction gas-producer plant shall work satisfactorily through a wide range of load on the engine, it will be necessary to have a sympathetic and accurate adjustment of the amount of steam used to the amount of gas used by the engine. There are several devices for accomplish- ing this result ; Smith's is shown in Fig. 67 and 68, and de- scribed in 214. The author's is shown in Fig. 71 and described in 216. Dowson and Wintherthur of England, and Pierson of France, also have devices for securing this regulation. 209. American types of suction gas-producers. The suction gas-producer is comparatively new in this country, yet in the short time that it has been on the market a large number have been placed in successful operation. The larger part of producers built and installed in this country have not been original American designs, but are either built under European patents or else have been modeled after European types. 148 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. All the types that are now on the market (June, 1905) are herein illustrated and some are described in detail. Fig. 51 '* ~ shows the Wood; Fig. 52, the Otto; Fig. 53, the Weber; Fig. 54, the Backus; Fig. 55, the Wile suction gas-producer. 210. Nagel suction gas-producer. This is shown in Fig. 56. A is the producer body with grate AMERICAN SUCTION GAS-PRODUCERS. 149 Producer. Vaporizer. Scrubber. Equalizer. FIG. 52. OTTO SUCTION GAS-PRODUCER, 150 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. B and ash pit C. D is the fuel magazine which is placed over and above the vaporizer E. The air enters the vaporizer at F, then goes to the ash pit by means of pipe G. The gases escape at H, then go down pipe / and around the deflector J, and into the coke scrubber K; then down through pipe L to equalizer M , Blower. Producer Vaporizer. Scrubber. FIG. 53. WEBER SUCTION GAS-PRODUCER. and then to the engine through pipe N. The object of J is to deflect impurities in the gas downward into the trap below. is the hand blower for starting the fire in the producer. 211. Pintsch suction gas-producer. This is shown in Fig. 57 and 58. Referring to the former, A is the hand blower. B is an ash tube to water-sealed ash trough C. D is the body of producer and has a charging hopper E. F is the vaporizer with vent pipe G and trap H. I is the usual form of coke scrubber. J is a two-tray purifier. K is an automatic regulator 1 1 151 152 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. which operates as follows : The spring M acts upward and tends to keep the dome L of the reservoir full of gas. When the engine draws gas from the regulator, the dome moves down on account of the exterior atmospheric pressure, but is drawn back again by the spring; in so doing, it sucks gas from the pro- ducer. The range of travel of the dome L may be regulated by varying the tension on spring M. Thus, instead of the suction action taking place only during the charging stroke of the engine, the actual gas-making is carried on for a longer period. FIG. 55. WILE SUCTION GAS-PRODUCER. 212. American Crossley suction gas-producer. The construction and arrangement of this producer is shown in Fig. 59, 60, and 61. The producer consists of a cylindrical plate steel shell, lined with firebrick and provided at its bottom with a shaking grate A, ash pit F, and door G. The grate is oper- rated from the outside of the producer by means of the lever as shown. B is a sealed hopper, so arranged that a charge of fuel may be placed in the hopper top C, and then allowed to fall into the feed tube D without opening the producer to the outside air. The feed tube conducts the fuel down to where combustion takes place. E is a waste heat vaporizer and has a water-jacket extension around the feed tube D. The object of this vaporizer AMERICAN SUCTION GAS-PRODUCERS. 153 is to furnish the steam required in the producer; the water in E is maintained at a fixed level by means of the tank S and float shown on the right side of Fig. 60. The gas-cleaning apparatus consists of a wet scrubber, hy- draulic box, and a combination wet and dry scrubber. The first consists of a plate steel cylinder, filled with coke and mounted on the hydraulic box. Water is introduced at the top of both 154 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. AMERICAN SUCTION GAS-PRODUCERS. 155 156 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. wet scrubbers in the form of a spray and trickles down into the hydraulic box underneath. The gas from the producer enters the first scrubber near the top and passes downward into the FIG. 59. CROSSLEY SUCTION GAS-PRODUCER. hydraulic box which contains a water seal with the necessary overflow; from here the gas goes into the combination scrubber, the wet section being constructed the same as the first wet scrub- ber, having but an extension mounted on its top, in which are AMERICAN SUCTION GAS-PRODUCERS. 157 placed trays containing shavings, excelsior, or similar material through which the gas filters and in which it gives up its mois- ture. While the fan R is being used to start the fire in the pro- ducer, the purge pipe is kept open to the atmosphere. FIG. 60. CROSS-SECTION OF CROSSLEY SUCTION GAS-PRODUCER. H is a poke hole for barring the fire in the producer, and Q is a hand hole for removing sediment from the water jacket. As shown in Fig. 59, cleaning doors are placed above the grate level to facilitate the cleaning of the interior of the producer. 158 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. AMERICAN SUCTION GAS-PRODUCERS. 159 The air is supplied to the ash pit from two sources, known as the primary and secondary supply. The primary supply enters directly from the outside air through the pipe J and is sucked up through the fuel bed. The secondary supply enters the top of the producer through valves K, passes over the surface of the water in the vaporizer and descends through side pipes L, heavily FIG. 62. SECTION OF FAIRBANKS-MORSE SUCTION GAS-PRODUCER. charged with steam, to the air boxes M, through which it circu- lates, and from which it is delivered to the ash pit through the nipples N. 213. Fairbanks-Morse suction gas-producer. This producer is shown in Fig. 62 and 63. Referring to the former, A is the producer composed of a cylindrical plate steel shell and firebrick lining. B is the fuel magazine charged by means of valve D from the fuel hopper C, which is hermetically 160 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. sealed by the lid E, and thus it is possible to charge B from C without permitting any outside air to enter the producer. The fire is supported on the grates F, which discharge the ashes into the ash pit G, which is accessible by means of the door H. I is the vaporizer for furnishing the fuel bed with steam; on the larger sizes of this producer, the vaporizer is removed from FIG. 63. ASSEMBLY OF FAIRBANKS-MORSE SUCTION GAS-PRODUCER. the top and placed on the side, as shown in Fig. 63. The air is drawn in through opening J and then, passing over the surface of the water in /, the steam becomes mixed with the air and the two then go down through pipe K and up into the fuel bed in A. By means of valve L the gas may be discharged into the atmos- phere while the producer is being blown up with the hand blower M , preparatory to starting. N is the usual form of coke scrubber with water spray at top. are hand holes for cleaning purposes. The object of the gas AMERICAN SUCTION GAS-PRODUCERS. 161 tank P is to form a storage receiver near the engine so that fluc- tuations in the requirements of the engine will be equalized. 214. Smith suction gas-producer. This producer is a radical departure from the usual practice and is shown in Fig. 64, 65, 66, 67, and 68. Referring to Fig. 65, the grate proper is a flat circular grid A, supported on the top of the frustum of a cone B, which rests on an annular ring C that is supported by chains D. By means of the lateral flexibility of the chains the grate may be swung in any direction. E E are cast-iron bosh plates for giving lateral support to the ash bed. A FIG. 64. SMITH SUCTION GAS-PRODUCER. space of four or five inches is allowed between the lower ends of E and the top of the grate, thus giving ample space for the removal of clinkers. Referring to Fig. 66, A is the wall of the annular charging hop- per and B the water-seal trough. D is the hopper valve which is secured by means of pin L to lever E; this is secured to shaft F which is turned by handle G. H is a spring used to keep D up against A. K is a shield surrounding H, F, and hub M. T is the hopper cover; since the producer is under a partial vacuum, the water seal between T and A rises to level S. 162 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. Referring to Fig. 67 and 68, A is the exhaust inlet from the engine to the superheating chamber B, which contains the pipes C, which are heated from the engine exhaust and through which the air and water are passed. D is a shaft on which the balanced weighing vessel E is supported; the latter has a rod F with cir- cular vane G which is arranged to move in the curved inlet pipe H. I is an orifice in E, the amount of water passing through FIG. 65. DETAIL OF SWINGING GRATE OF SMITH SUCTION GAS-PRODUCER. / being adjusted by the screw J. K is the wa+er-inlet pipe con- trolled by the valve L. If more water comes into E than passes out of 7, the surplus is drained to M by an opening in E not shown in the figure and then out through the overflow N. The operation is as follows: When air is drawn into the pro- ducer, the vane G is moved to the position shown by the dotted lines, thus turning E and allowing a certain amount of water to flow out of 7, the quantity of water being proportional to the amount of the movement of G and E. When the suction stroke of the engine is finished, the counterweight swings E back to AMERICAN SUCTION GAS-PRODUCERS. 163 164 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. its normal position. As the water and air pass into C, the former is converted into superheated steam and the latter is pre-heated to about 300 degrees F. Since the heat of the outgoing gases from the producer is not required to raise the steam necessary for the gas-making process, the gas outlet may be placed higher above the grate, thereby cooling the outgoing gases by contact with the cold fuel above the fire. In the scrubber which is shown on the right side of Fig. 64, FIG. 67. WATER REGULATOR FOR SMITH SUCTION GAS-PRODUCER. the cleaning and cooling of the gas is accomplished by passing the gas through a series of wooden slats that are continually sprayed with water. When the gas leaves the scrubber, it is passed through a separator (shown over and above the scrubber) which operates on the same principle as a steam separator. 215. Baltimore suction gas-producer. This is shown in Fig. 69. A is the body of the producer, the fuel resting on grates B. C is the charging hopper. D is the AMERICAN SUCTION GAS-PRODUCERS. 165 vaporizer, containing the gas outlets E. F is the collecting chamber from which the gas goes to pipe H or vent pipe I. J is the air heater that is connected with ash pit L by pipe K. M B mti^wm T 1 I X" C r" aVA.WXV'AVO^kV^'^VV Air and Steam to Producer FIG. 68. DETAIL WATER REGULATOR AND SUPERHEATER OF SMITH SUCTION GAS-PRODUCER. is a steam pipe connecting D with L. N is the air inlet. is a tower scrubber with blocks of wood P and a filter chamber Q. 216. Wyer suction gas-producer. This is shown in Fig. 70 and 71. Referring to Fig. 70, A is 166 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. the shaking grate which is operated by lever B. The grate may also be raised and lowered by means of a screw not shown in the illustration. C is a fuel pre-heating tube with renewable mouthpiece D. The gas must go up and around C and then down FIG. 69. BALTIMORE SUCTION GAS-PRODUCER. the port E. In this way the gas gives up a large part of its sen- sible heat to the column of fuel in C. When the lid F is in place the cone G is lowered, and any vapors that are evolved from the fuel in C pass down in port H and by means of pipe / are led to the ash pit; these vapors then go up through the fuel bed and are broken up there into permanent gases. The other details of the construction are evident from the illustration. The air is pre-heated and the water is vaporized and the resulting steam AMERICAN SUCTION GAS-PRODUCERS. 167 superheated by means of a tubular heater placed near the engine, which utilizes a portion of the heat in the exhaust gases. Fig. 71 shows the automatic water regulator, for a hit-and-miss gas engine. J is a piston with stem K upon which is the follower FIG. 70. WYER SUCTION GAS-PRODUCER. piston L; M is the inlet port that is supplied with water from the trap N, through which the jacket water circulates. is a port that leads the water to the vaporizer. J is connected to some mechanism of the engine whose movement is controlled by the governor. Every time that an explosion takes place, port M is closed and port opened. and the water contained between / and L passes down into 0. Then the spring P draws J and L 168 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. back to their starting position. Thus a small amount of water is admitted to the vaporizer every time that the engine draws in a charge of gas; this amount may be adjusted by changing the 'o FIG. 71. WYER WATER REGULATOR. distance between L and /. This secures an accurate and posi- tive regulation of water under any variation of load. A similar device working in a vertical direction is used for throttling engines. CHAPTER XVII. GAS CLEANING. 217. Object of cleaning. The object in cleaning producer-gas is to remove such con- stituents as have a deleterious effect on the particular work that the gas has to do, the use of the gas determining the extent of cleaning or the purity of the gas. Constituents that would be harmless where the gas is to be burned in a furnace might make the gas utterly worthless for use in engines. Further, in some cases, the cleaning of gas to a degree of purity suitable for engine use would prohibit the use of such cleaned gas in furnaces on account of the additional cost. The only general rule that may be laid down is that of the adaptability of the gas to its particular use. The removal of the tar is of such vital importance that it is discussed in detail in Chapter 23. 218. Classification of methods. The methods used in cleaning gas may be classified as follows: 1. Deflectors. 2. Liquid scrubbers. a. Sprays. 6. Films. c. Seals. 3. Coolers. 4. Absorbers or filters. 5. Rotating scrubbers. a. Slow speed (mixing action). 6. High speed (centrifugal force). These classified types are generally not used alone but two or more are usually combined; thus, in Fig. 57, we have a com- bination of deflector, spray scrubber, and absorber. The principle of operation of the respective types will now be discussed in detail. 169 170 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. 219. Deflectors. The operation of these depends upon the fact that when the motion of a rapidly moving volume of gas, carrying matter in suspension, is suddenly checked or deflected by impinging against an obstruction, a part of the suspended matter will settle down into a chamber if one is provided and at the same time the gas will go around the obstruction or deflector. If the settling ^2^5 y -^ < > r l > x- n > > x- i p u *j -7 ^ V > ___ V == ? _ j -k JL V ^= ^ * __ _ 1_" FIG. 72. MOISTURE COLLECTOR. chamber is provided with a means for cleaning same, the matter collected from the gas may be removed from time to time as desired. Fig. 72 is a moisture collector. Fig. 73 shows an arrangement for collecting dust, while Fig. 74 is intended to FIG. 73. DUST COLLECTOR. FIG. 74. MOIS- TURE COLLECTOR. dry gas by catching the water carried in suspension. Fig. 75 shows the arrangement of a device to remove tar from gas. It consists of an inclosed tank A with gas inlet B and out- let C. D are deflectors made of sheet brass, a full sized detail GAS CLEANING. 171 of these being shown in Fig. 76. As the gas passes through the apparatus, it must pass through D, and in so doing is split up FIG. 75. TAR COLLECTOR. into fine streams and the tar is deposited on the brass sheets, where it then drains into the tar seal below. This has been used N \ ... / oooooo/ ooooo f ooooooJ *~oooooo\ ooooo \ OOOOOOJ FIG. 76. FULL SIZE DETAIL OF DEFLECTOR IN TAR COLLECTOR. 172 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. with some success in Europe, but the clogging up of the small holes gives trouble. 220. Liquid scrubbers. Water is usually used in connection with the cleaning of pro- ducer-gas, and this has a twofold action: First, to condense any steam that may be in the gas. Second, to wet the particles carried in suspension and thus cause them to settle down to the bottom of the scrubber where they may be drained off at inter- vals. Fig. 62 shows a spray. A film of water is used in the scrubber shown in Fig. 77. Here the gas enters at A and leaves at B, the water coming in at C and running down over the shelves D. As the water drops from one shelf to another in the form of a film, the gas passes through it, and the suspended matter is washed out. In all liquid scrubbers, it is desirable to have opposite currents. (See 26.) Water seals or bell washers are discussed in 242. 221. Coolers. The function of the cooler is to precipitate the condensible constituents, or simply to reduce the temperature of the gas by passing it through air- or water-cooled vessels. A cooler of this type, which is shown in Fig. 78, has been used extensively in Sweden for removing the moisture, tar, and acetic acid in pro- ducer-gas made from wood. In the arrangement shown, the gas enters at A, then passes down through the annular opening B between the water jackets C and D; as cold water is kept circu- lating through these, the walls of B are kept cool, which in turn cools the gas and causes the condensible constituents to be pre- cipitated in the tank E below; the cleaned gas passes out at F. Air coolers are sometimes used for reducing the temperature of gas before it goes to a gas engine. 222. Absorbers or filters. These act by absorbing impurities in the gas and they are frequently used for removing globules of tar and water. Saw- dust, shavings, excelsior, coke, and charcoal are used for this purpose; it is evident that these absorbing substances must be kept reasonably clean, since, if they become clogged up or satu- rated with impurities, their efficiency is materially decreased, and they may become useless. The purifier J, in Fig. 57, is of this type. GAS CLEANING. 173 FIG. 77. FILM SCRUBBER. FIG. 78. WIMAN GAS COOLER. 174 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. 223. Rotating scrubbers. These may be divided into slow- and high-speed types. To separate the impurities, the slow-speed type depends upon a FIG. 79. SECTION OF WINDHAUSEN GAS-SCRUBBER. thorough mixture of the gas and a liquor, usually water; the high- speed, on the centrifugal force of the impurities in the gas. GAS CLEANING. 175 A German design of the slow-speed type is shown in Fig. 79. It consists of a central shaft, D, driven in the direction shown by pulley G; at the upper end of D is a fan /. The gas enters at A and is drawn up through B and C by 7. E is an inner and F an outer shell attached to D and rotated with it. J is the water- inlet pipe. The upper end of D is hollow, and water is forced FIG. 80. HORIZONTAL SECTION OF CENTRIFUGAL SCRUBBER. into it and out into the chamber formed by L and M. As C is perforated between L and M, the water goes on through and impinges against F; after flowing down, it is caught in the annular pan H and channel N and then goes out at 0. K is the gas out- let. The operation is as follows : As the fan draws the gas through the apparatus, the gas and water travel in opposite directions in C; and as this space is made very thin, the gas comes in close contact with the film of water and the impurities are washed down into H and out at 0. An English design of the centrifugal type is shown in Fig. 80 and 81. The gas enters at A and is given a high peripheral velocity by vanes B. C is a partition disc that compels the gas 176 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. to go out to its circumference in order to pass through the appa- ratus. In so doing, the impurities are dashed against the casing F and then drained out at E, while the purified gas passes out at D. The machine is simple, does not require very much power, and has given good results in the elimination of dust, water, and tar. FIG. 81. VERTICAL SECTION OF CENTRIFUGAL SCRUBBER. 224. Proportions of tower scrubbers. Height is an advantage so that the gas may be more easily broken up and more wet surface may be presented. In pressure- gas plants the diameter is usually one-sixth the height, while in suction-gas plants the diameter is one-fourth the height. The volume of the scrubber should be about six times the normal fuel volume of the producer. CHAPTER XVIII. BY-PRODUCT GAS-PRODUCERS. 225. Definition of by-product gas-producer. The by-product gas-producer, in addition to making gas for a certain purpose, also produces one or more auxiliary products which are based on certain constituents of the raw fuel and re- sulting gas. The by-products are usually based on constituents that are otherwise useless and would go to waste. The number, nature, and value of the by-products and the method of collect- ing will depend on the composition of the raw fuel, type of appa- ratus, cost of operating, and commercial value of the products saved. 226. Number and value of by-products. Coal will generally contain about 1.5 per cent of nitrogen; in the process of gasification in the producer about 15 per cent of this quantity of nitrogen is given off in the form of ammonia. The use of an excess of steam will greatly increase the yield of ammonia. By means of suitable apparatus, the ammonia may be recovered by combining it with some acid. Diluted sulphuric acid is generally used, as this produces the sulphate of ammonia, which is the most valuable and important by-product at present. This is about the only one saved and is discussed in 227. Its principal use is that of an artificial fertilizer. Tar is sometimes saved, but this is so troublesome that the commercial value of the product does not justify the additional expense. However, this refers only to cases where the tar is recovered for its in- trinsic value, and does not apply to the many instances where the tar must be removed from the gas in order that it may be used for engine work. (See 280, and Chapter 23.) The factors which will determine whether a by-product pro- ducer-gas plant will be profitable or feasible are as follows: (1) Increased cost of installation and maintenance; (2) Salary of skilled technical chemist who will control all operations of 177 178 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. the plant ; (3) Cost of raw fuel ; (4) Cost of chemicals for process ; (5) Commercial value and sale of by-product; (6) Use of gas. 1. On account of the extensive scrubbing apparatus required, the cost of installation and maintenance for a by-product plant will be considerably higher than for an ordinary plant. How- ever, as a by-product plant must be on an extensive scale from the very nature of the case, the cost of labor-saving appliances will be decreased. This is an important advantage, since the use of labor-saving devices is imperative in all well designed plants. 2. For a by-product plant to be successful, it must be in the control of a skilled technical chemist. Not only must the in- coming raw material be sampled and analyzed at regular inter- vals, but the finished by-products must be kept up to a certain definite standard in order that they may be of commercial value. The laws of some states prescribe the composition of various by- products, and in such cases it is imperative to keep the quality up to the legal standard in order to secure a safe market. This can be done only by careful supervision. 3. In general, a cheaper grade of fuel may be used in the by- product process than in the ordinary system. 4. In some cases, the cost of the chemicals required would be so high as to make the process unprofitable. 5. The successful selling of the by-products will be the most important factor. Since ammonia sulphate is at present about the only product of value, it is evident that the installation of a large number of by-product plants would cause an over-produc- tion of it and would result in a decrease in the market price, un- less the use of ammonia sulphate can be increased at the same rate with the production, thus maintaining an economical equi- librium. Companies now operating or about to install by-product plants will find it advantageous commercially to interest farmers in the value and use of ammonia sulphate. This will require judicious advertising and the dissemination of simple and au- thentic data with regard to the application of this fertilizer to the different soils. Most of the failures made in its use have been due to ignorance, i.e., using it in improper quantities, by poor methods, or on soils for which it is not adapted. The inevi- table failures following its indiscriminate application will be sure to react against its extensive use, whereas the success following BY-PRODUCT GAS-PRODUCERS. 179 its scientific use will greatly augment the sales. Hence the vital importance of the statements in the preceding sentences. 6. A by-product process will make a cleaner gas from a low- grade fuel than the average producer. If the gas is to be used for power purposes this is an important advantage. 227. Ammonia sulphate. Since this is the only by-product of value, it will be desirable to have a clear understanding of its properties and uses. The high value of ammonia salts as a fertilizer for certain soils has long been recognized. "Ammonia sulphate is one of the most concen- trated forms in which ammonia can be applied to the soil, and is, at the same time, one of the most active and readily available forms, being decidedly quicker in its action than any form of organo-nitrogenous matter. This manure is a very valuable one on clayey and loamy soils, while for cereals, potatoes, and some other crops it is used with great success, especially where it can be harrowed in and covered with the soil." (B 349.) " Pure ammonia sulphate is a whitish crystalline salt, extremely soluble in water. The commercial article, however, is generally grayish or brownish in color, owing to the presence of slight quantities of impurities. The pure salt should contain 25.75 per cent of ammonia; but the commercial article is generally sold on a basis of 24.5 per cent. A useful test of its purity is the fact that, when subjected to a red heat, it should almost entirely volatilize, leaving very little residue. The chief impurities which it is likely to contain are an excess of moisture, free acid, or the presence of insoluble matter." (B 350.) Ammonium sulphocyanate, which is an extremely poisonous substance for plants, may sometimes be present. To test for this, treat a sample of the ammonia sulphate with ferric chloride; if the sulphocyanate is present, the sample will change to a blood- red color. " The chief advantages of ammonia sulphate are that it is very concentrated, therefore reducing the cost of handling; it is always in the same form, a distinct and definite product, thus rendering its purchase a safe proceeding. It is quick to act, thus making it a very useful form, especially for quick-growing crops. Its physical character is such as to permit its ready distribution in a mixture." (B 348.) 180 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. The fact that this fertilizer is not adapted for all soils, and in fact is worthless for some, is illustrated in the following. For instance, it is practically worthless on soils containing chalk or lime, for when it is applied the following reactions take place: (NIL) 2 SO 4 + CaCO 3 = CaSO 4 + (NH 4 ) 2 CDs. (Volatile.) (NH 4 ) 2 S0 4 + CaO = CaS0 4 + H 2 + 2NH 3 . (Volatile.) As the ammonium compound in either case is volatile, it will simply pass off to the atmosphere without nourishing the plant. 228. Method of recovering by-products. There are numerous patents on different methods for recover- ing the by-products. They all embody the following fundamental points: The gas on leaving the producer is cooled by passing through radiating appliances and then goes to various forms of scrubbers and washers, where it is treated with some reagent whose function is to precipitate or absorb some of the constitu- ents in the gas, which is then thoroughly washed with water to remove the fine dust and condense' the tar. Sometimes the gas is further treated to remove its moisture. 229. Mond by-product producer-gas process. This was the first process to be commercially successful and is the only one that has been introduced in this country. It was developed and perfected by Dr. Ludwig Mond of England. A diagrammatic drawing of a Mond plant is shown in Fig. 82. A is the producer with the charging hopper B and hopper exten- sion C. The producer consists of two steel shells which thus form an annular space in which the air and steam may be heated by circulating around the producer. The lower end of the producer has a cone D which extends into the ash trough E, and with the water there forms a water seal. F is a thin firebrick lining. G are recuperator pipes which cool the gas and pre-heat the air and steam passing around them. H is a washer with revolving blades I. J is the pipe connecting H with ammonia-recovery tower K, which is filled with checkerwork. L is the acid-supply tank. M is the drain tank from K, the liquor in the latter being led to M by pipe N. is the liquor- circulating pump which carries the liquor to the top of K by BY-PRODUCT GAS-PRODUCERS. 181 182 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. means of pipe P. Q is a pipe leading to the concentrated am- monia sulphate tank. R is the pipe connecting K with the gas-cooling tower S, which is filled with checkerwork. T is the gas exit; from here the gas is delivered to the mains. U is the air-heating tower, also filled with checkerwork. V and X are pumps for circulating hot and cold water respec- tively, by means of pipes W and Y. Z is the air blower connected to U by pipe a. b b, tar drains, c is a pipe for admitting some of the engine exhaust gases to the air and steam blast. The operation is as follows: As the coal is fed to C, the heat of the surrounding gases causes the moisture and some of the tarry vapors to be distilled off. In order to escape from C, these vapors must pass down and into the hot fuel bed, where they are broken up and converted into fixed gases. The fuel is kept at a dull red heat by an excessive amount of superheated steam; 3 Ib. of air and 2J Ib. steam at 250 degrees C. are furnished per pound of fuel. About one-sixth of the steam is decomposed in the pro- ducer, the remainder being condensed in the scrubbing apparatus. The large amount of steam is used to prevent the decomposition of the ammonia, the formation of clinkers, and to secure a low and uniform temperature. The gas leaves the producer at about 500 degrees C., and, in passing through the recuperators G, gives up a large portion of its sensible heat to the incoming steam and air. From G the gas goes to the mechanical washer H, where the revolving dashers / fill the chamber with fine water spray which washes the dust and soot out of the gas. Tarry products will also be condensed and these may be skimmed off at intervals. In this washer the gas is cooled and charged with steam, but not to the saturation point. This is important, as it is very desirable to prevent the formation of water in the ammonia-recovery tower, which would be the inevitable result of allowing the gas to become saturated. From H the gas goes to the tower K. The checkerwork is kept saturated with a diluted solution of sulphuric acid from the pipe P. When the ammonia in the gas comes into contact with the acid, sulphate of ammonia is formed. Thus: 2NH 3 + KUSCX = (NIL) 2 SO 4 It will be noticed that the acid and the gas travel in opposite BY-PRODUCT GAS-PRODUCERS. 183 directions ( 26), thus securing a very close contact of the two. The acid liquor is kept in circulation by pump until it contains about 36 per cent of sulphate of ammonia. The con- tinuity of the process is maintained by removing some of the sul- phate-laden liquor at intervals by means of pipe Q and adding a corresponding amount of fresh diluted acid from tank L. The solution of the sulphate is then reduced to a solid state by evap- oration. The gas then goes to the cooling tower S, where the tempera- ture is reduced to about 55 degrees C. by means of cool water introduced from Y. Thus the water condenses the water vapor in the gas and takes up the sensible and latent heat. The gas is now ready for delivery to the mains. The hot water accumulating at the bottom of S has a tempera- ture of about 75 degrees C. and is withdrawn by pump V and delivered by pipe W to the top of the air-heating tower U. The air is forced into the system by the rotary blower Z, and as it comes up through U is heated and saturated with water vapor. From U the air goes around the recuperators G, where it absorbs more heat and is then delivered to the producer. The water in coming down through U is cooled to about 40 degrees C. Pump X then delivers this to the top of the tower S. The tar collecting in the bottom of S and U may be removed by means of drain pipes b. Steam is usually supplied by a small auxiliary boiler. The Mond producer may be used without the by-product feature by omitting the ammonia tower from the scrubbing apparatus. In such a case part of the engine exhaust gases are introduced at c; the CO 2 contained in these is reduced to CO in the producer. The object of this is to keep the temperature of the producer down without the use of the excess of steam required in the by-product system. 230. Distinctive features of Mond process. 1. The manufacture of a gas of uniform quality, and clean enough for engine use, from cheap bituminous slack. 2. The use of a large excess of superheated steam in the pro- ducer, thus eliminating clinkering. 3. The use of recuperation and regeneration to conserve the heat loss. 184 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. 4. The recovery of 70 per cent of the nitrogen in the slack and the conversion of this into sulphate of ammonia, each ton of slack yielding about 90 Ib. of the sulphate. 5. "The method of continuously employing the water in cir- culation as the heat-carrying agent between the hot gas in one tower and the cold air in another, and the method of recovering from the hot gas, by this continuous cyclical exchange of heat, a large proportion of the steam required for the blast." (B 201.) CHAPTER XIX. BY-PRODUCT COKE-OVEN GAS-PRODUCERS. 231. Status and future. The composition (see table 4, p. 50) of coke-oven gas and the method of manufacture are radically different from producer- gas. However, the method used in handling the raw fuel and resulting gas, the treatment of the by-products, and the probable extensive development of the system make it desirable to have a clear understanding of its value, scope, method of operation, and type of apparatus used. The by-product coke-oven process has already attained a well recognized position in the metallurgical field, and is destined to play an important part in the fuel supply , of the larger cities and thickly populated districts. To such communities, the by- product oven delivers gas for illuminating, power, and fuel pur- poses on a basis as favorable as that of any other method, and at the same time yields coke suitable for domestic and industrial consumption which docs not produce smoke. The approaching exhaustion of the anthracite mines prevents any reduction in the price of anthracite coal, and the consequent increase in the use of soft coal is arousing bitter opposition, particularly in those localities hitherto comparatively free from the smoke nuisance. The by-product oven offers a ready solution of the domestic smoke problem. It seems, therefore, beyond doubt that the by- product oven will play a large part in the future industrial develop- ment of this country. Over 70 per cent of the ovens built in this country may be classed under two heads, viz. : the Otto-Hoffman oven, the origi- nal type built in Europe by Dr. C. Otto & Company, and the United-Otto oven, which is the improved type resulting from the American developments and modifications. 232. Otto-Hoffman Oven. The Otto-Hoffman oven in the American form is shown in sectional perspective in Fig. 83. The coking chamber itself con- 185 186 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. BY-PRODUCT COKE-OVEN GAS-PRODUCERS. 187 sists of a long, narrow retort of firebrick construction, a number of such retorts, usually 50, being placed side by side to form a battery. The dimensions of this retort are 33 ft. long, 6J ft. high, and from 17 in. to 22 in. in width, containing 6 to 7 net tons of coal at a charge. The walls of the retort are built with ver- tical internal flues, heated by gas. The ends of the retorts are closed by iron doors, lined with firebrick, fitting closely to the brickwork and luted with clay. These are raised and lowered by a winch or by an electrical lifting device. The coal is charged into the ovens from three larries moved by hand along tracks, laid on the oven top or, in the later plants, by a single electrically operated larry as shown in the illustration. The single larry has spouts which deliver the coal from corresponding openings in the oven top to the oven chamber below. The coke is pushed out of the oven by the electrically operated pusher and is received and quenched on a wharf, from which it is loaded by hand into railroad cars on a depressed track alongside. The heating of the oven is done by gas, returned from the condensing house through lines running along each side of the battery, there being a burner at each end of each oven. Only one burner is used at a time. The air for combustion is taken in at the end of the battery, where the gas and air reversing valves are located, and is led through the underground passages, shown in the figure, to the flues beneath the regenerative chambers. These extend the whole length of the oven battery and are filled with checker- brick. The air rising through this checkerwork is heated to a high degree, passing then through uptake connections to the space beneath the floor of the oven chambers, and through lateral ports to the combustion chamber, where it meets the gas from the burner. The burning gases rise through the vertical flues of half the wall, pass along the horizontal connecting flue above, and down the remaining vertical flues to the horizontal flues below, thence passing to the regenerator, where their sensible heat is absorbed by the checkerwork. From there they are led to the lower regenerator flue, past the reversing valve to the draft stack. On the reversal of the air and gas, the gas burner on the other end of the oven comes into use, the air passing up through the heated regenerator on that side, and to the gas chamber and combustion chamber, the heated gases passing in a reverse direction through the wall flues downward through the 188 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. regenerator and so to the stack. The period of reversal is 30 minutes. 233. Treatment of gas. The gas given off from the coal during the coking operation is led away from the oven through uptake pipes furnished with valves to the gas-collecting mains. If the surplus gas is to be used for fuel purposes only, one gas-collecting main is needed, but if it is required to make illuminating gas, two are used - one to take the portion of the gas delivered during the first part of the coking time, known as the "rich gas." This fraction is higher in illuminants than the last portion of the gas, and is there- fore better suited for distribution purposes. This separation is done by the application of the principle of fractional distillation ( 49). The last portion of the gas is led off into the fuel-gas main and is used for heating the ovens. The two portions of the gas are kept absolutely separate through the subsequent cooling and condensing operations, the condensing house being so arranged as to handle them in separate systems, usually arranged in parallel. 234. United-Otto oven. This is a modification of the type described in the previous section. The adoption of the underfired principle in this oven admits of properly heating' a longer retort of greater coal capacity than would be possible with the older system of a single burner at either end; at the same time the retention of the regenerative system aids the heat distribution and permits each oven battery to be an economical unit without the use of the steam boiler auxiliary to absorb the heat from the waste gases. The details of this type of oven are shown in the cross-section in Fig. 84, which also gives the arrangement of the coal conveyors, coal bin, pusher, and quencher. The oven itself is a rectangular retort from 33 to 43 ft. long, 7 to 9 ft. high, and 17 in. wide, the dimensions varying with the characteristics of the coal that is to be used. The retort walls, top and bottom, are composed of refractory material, and the masonry is supported on a steel and concrete substructure so as to be entirely independent of the regenerative chambers below. This avoids the cracking of the oven walls and the subsequent loss of gas liable to occur from the expansion and contraction of the heated regenerator walls BY-PRODUCT COKE-OVEN GAS-PRODUCERS, 189 190 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. beneath the oven structure. The open substructure admits of a complete anchoring system joining the buckstays above and be- low, and holding the oven walls securely in place. The steel work of the substructure is protected from the heated brick- work above by a course of hollow tile, which also serves to retain the heat in the ovens themselves. The oven chamber is closed at either end by doors, which are of the self-sealing type, replacing clay luted doors. These do away with the labor of mixing and applying the luting clay. 235. Wall construction. The construction of the oven walls is a point of vital impor- tance. Shaped brick ground to exact size by carborundum grind- ing wheels are used. This results in a practically gas-tight wall of great strength. The resistance of the wall is enhanced by the vertical flue sys- tem. As will be seen in the drawing, the heating flues run per- pendicularly along all that portion of the oven wall against which the coal can exert any pressure. The divisions between the flues form vertical strengthening ribs, and tie the walls into a single homogeneous whole. This is of vital importance when coals of only slightly shrinking or even expanding nature are to be coked. 236. Heating systems. The heating of the United-Otto ovens is accomplished, as in the Otto-Hoffman oven, by the use of gas returned from the conden- sing house through the two mains shown beneath the middle portion of the ovens in Fig. 84. The air for combustion is sup- plied to the regenerator by a fan, this method aiding in the equal distribution of the air to each oven and reducing the amount of stack draft necessary. 237. Operation. The gas is admitted through a burner at each end and four or six burners in the bottom, placed symmetrically on each side of the middle line. This avoids the use of bottom burners above the regenerative chambers, w r here they are less easy of access for cleaning and regulation. The surface of the checker brick in the regenerators is so pro- portioned as to render efficient service in absorbing the heat from the waste gases. The temperature of the waste gases leaving BY-PRODUCT COKE-OVEN GAS-PRODUCERS. 191 the regenerators is not high enough to cause deterioration of cast-iron reversing valves of the usual form. The coal received in the cars is dumped into track hoppers below the ground level and transported by the coal conveyor to the storage bin above. From this bin the coal is drawn through chutes to the charging larry beneath, which is operated by elec- tric motors and travels on rails over the top of the oven battery. From the larry the coal is charged into the ovens by means of the chutes, which correspond with the openings in the oven top. The charge is then leveled to an even surface in the oven by an electrically operated leveling bar, which travels back and forth through an opening in the oven door. This leveling bar is car- ried on the pusher, and is operated by the pusherman. When this is completed, the oven is sealed up and the valve leading to the gas main is opened. There are two of these mains provided, the one for the rich gas and the other for the fuel gas. When the coking period has elapsed, the ovens are disconnected from the gas mains, the doors are removed, and the coke charge pushed out of the oven by the ram or pusher seen on the left-hand side. 238. Quencher. The quencher is shown in actual operation in Fig. 85. The coke is received in the quencher, which is a rectangular box of cast iron with cellular walls to admit of water cooling. It is large enough to take in the whole oven charge, and its bottom is formed of a motor-driven chain conveyor. The whole machine travels on rails parallel to the oven battery, and connection is made with the particular oven to be pushed by means of swing doors and a drop bottom which guide the coke charge to the receptacle, assisted by the moving conveyor bottom. When the charge is received the doors are closed and the coke quenched with water. The immediate and violent generation of steam is taken care of by the escape stack shown in the illustration. The whole receptacle is filled with steam, practically excluding the air, so that the silvery gray color of the coke is preserved, as in the beehive product. When the quenching is complete the coke is discharged into the car on the track adjoining. Another form of quencher consists of a steel car having a slop- ing bottom, which travels along the oven battery as described above, and into which the coke falls as it is pushed out of the 192 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. oven and across the narrow oven platform. The coke lying in the car is quenched by means of a water hose. The motion of the car across the path of the coke leaving the oven serves to distribute it evenly on the floor of the car. Many of the older plants still quench the coke on a wharf built at the height of the oven bottom, and wide enough to take the whole oven charge easily. The coke pushed out on this wharf is spread out with hooks and quenched with a hose, as shown in Fig. 83, afterwards being loaded into railroad cars by barrows. BY-PRODUCT COKE-OVEN GAS-PRODUCERS. 193 239. Air and water coolers. These are shown in Fig. 86. The gas enters on the left, coming directly from the ovens. It first passes through air and water coolers, which lead the gas to and fro in ascending zigzag pas- sages, exposing a large surface for atmospheric cooling. A num- ber of these cooling units are arranged in parallel, so that any single one may be taken off for cleaning without disturbing the operation of the remainder. All are provided with an external sprinkling system, so that water cooling may be used in hot weather if necessary. The cross-section of the gas passages in this apparatus is long and narrow, so that the cooling surface is large for the volume of gas space. The further reduction of the gas temperature is accomplished by the use of rectangular water coolers of special design. The gas space is divided by successive baffles so that a tortuous path is followed, and the water circulation is made to flow through the tubes in an opposite direction; this gives a high efficiency of heat transmission and. permits economy in the use of cooling water. 240. Exhausters. These are of the positive rotary type, and are steam driven. The function of the exhauster is to remove the gas from the ovens and draw it through the mains and cooling apparatus, it being undesirable to rely upon the pressure generated by the gas evolution in the ovens to accomplish this. In order to avoid leakage of air into the ovens, a slight pressure is maintained on them at all times. The exhausters also force the gas through the scrubbing apparatus and deliver it to the ovens under pres- sure, or to the purifiers and storage gas holder in the case of the rich gas. The control of the gas passing through the system therefore centers in the exhauster room, and here is placed the gauge board, on which are carried the pressure and vacuum gauges showing the working conditions in the various apparatus. 241. Tar scrubbers. These are of the frictional type and remove the tar existing as a fine mist in the gas by passing it through small openings in successive thin steel diaphragms, the friction causing the tar to deposit in globules. With coal yielding considerable naphtha- line, the temperature at the scrubber must be raised enough to 194 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. BY-PRODUCT COKE-OVEN GAS-PRODUCERS. 195 overcome the stoppages occurring there from naphthaline de- posits. 242. Ammonia scrubbers. These are of the tower type, the gas passing upwards through a lattice work of wooden slats, and the scrubbing water passing downwards. Fresh water is used in the last scrubber, and the weak resulting liquor is used in the scrubbers preceding this, until it becomes strong enough for distillation. Another form of scrubber sometimes employed is of the rotary type. In this the gas passes through a cylindrical shell horizon- tally placed, through which passes a revolving shaft carrying wooden grids, lattice work on steel plates, which dip in com- partments filled with water, forming the lower portion of the cylinder, and thus present a constantly wetted surface to the gas passing through the upper part. The ammonia is absorbed by the water, as in the tower scrubber. Bell washers in which the gas is forced through a series of water seals have been successfully used. The gas leaving the ammonia scrubbers is sufficiently clean for use in oven heating, for transportation to a distance under pressure, or for use in gas engines in the majority of cases. For illumination purposes it should be passed through purifiers to remove the sulphur compounds present, as is the case with ordinary illuminating gas. The amount of sulphur present in the gas depends entirely upon the quality of coal used. 243. Recovery of ammonia. The ammonia obtained is in the form of a crude weak liquor, containing from 1 to 2 per cent of ammonia (NH 3 ). This is transformed by distillation into concentrated crude liquor, hav- ing 14 to 18 per cent NH 3 , or by combining it with sulphuric acid into ammonium sulphate. In the first instance it can be disposed of to the manufacturers of alkali, soap and chemicals of various forms. It may be further purified to form aqua ammonia, or by distillation and compression transformed into anhydrous ammonia, either of which is used in artificial refrigeration. 244. Benzol recovery. Benzol (C 6 H 6 ), or benzene, exists as a vapor in coke-oven gas. As it is an excellent illuminant, a large portion of the candle power is due to its presence. It can be recovered from the gas by passing through washers in which dead oil creosote is 196 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS, used as the scrubbing liquor. This oil absorbs the benzol and it may be recovered from the oil by fractional distillation and subsequent condensation. It is a colorless liquid possessing great inflammability and is used as a solvent of India rubber and in various chemical manufactures. It is much employed abroad as an enricher of illuminating gas, but the limited pro- duction and high price, as well as the general use of petroleum products for the same purpose, have militated against its intro- duction in this country. When the rich fraction of the gas is to be used for illuminating purposes, the removal of the benzol is clearly a detriment. It is, however, possible to obtain considerable benzol from the fuel- gas fraction, the loss in heating power being negligible. The transfer of this benzol without intermediate condensation to the rich fraction for its further enrichment is done by scrubbing the gas with dead oil creosote which absorbs the benzol, this oil in turn being deprived of its benzol by heating, and the benzol vapors mixed with the rich gas fraction. The process also has an advantage in its tendency to remove all naphthaline troubles. 245. Use of gas in engines. Coke-oven gas is well adapted for use in the gas engine for power purposes, the rich fraction having about 700 B. t. u. or the poor fraction having from 400 to 600 B. t. u. per cu. ft., according to the coal; or, in case the gas is not divided, the gen- eral run of gas averaging between these two in calorific power. In general, the gas as delivered from the condensing house may be considered ready for use in the engine cylinder without further necessity for purification. The small amount of sulphur present does not appear to have sufficient action upon the working parts of the engine to justify the cost of its removal. The experience of a number of foreign coke-oven works, where oxide purification apparatus was provided for the removal of the sulphur before admitting the gas to the engines, has resulted in the majority of cases in eliminating this process entirely. In some cases further scrubbing through sawdust or other mechanical puri- fiers has been resorted to, but with a thoroughly cleaned gas this is, of course, unnecessary. CHAPTER XX. PRODUCER-GAS FOR FIRING CERAMIC KILNS. 246. Status. While producer-gas has been used to a considerable extent in Europe for the heating of ceramic kilns, it has not been intro- duced to any extent in this country. This fact may be accounted for as follows : First, the limited literature on the subject and this of a fragmentary nature has made it generally impossible for engineers and manufacturers to secure reliable data on all the different phases of the problem. This ignorance of the subject has made it easy for many persons connected with the ceramic industry to entertain distorted and erroneous ideas of the ad- vantages and disadvantages of the use of producer-gas for such work. In some cases, the advocates of both sides of the ques- tion have gone to extremes and have lost sight of the funda- mental conditions of the problem. Second, the economical use of fuel has not always been neces- sary. In general, a gas-producer will do more work with a given quantity of fuel and will also make it possible to use a lower grade of fuel. Third, the absence or non-enforcement of laws against the smoke nuisance of ceramic plants. Since the gas-producer is an ideal solution for this problem, the enforcement of anti-smoke laws will result in an increased use of producers. Fourth, the conservatism against change; "this peculiarity must be sought in the ancient traditions of the potter." How- ever, as the customs and empirical recipes of the fathers are being rapidly replaced by the scientific methods and chemical formulae of the technically trained ceramic engineers, we may expect that future methods of burning ceramic kilns will have a more rational basis, and that the true value of producer-gas for such work will be appreciated. 197 198 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. Fifth, inadaptability of kiln to producer. The neglect to recognize that it is imperative to have the kiln adapted to the producer, or vice versa, has resulted in many costly failures. A producer that would give good results in firing a lime or cement kiln might be a complete failure in firing some types of brick or tile kilns. 247. Value. Seger (B 160) states: "The main point of gas-firing in all in- dustries lies in the utilization of low-grade fuel which, on account of its high content of ash, its content of water and impurities, as well as owing to its form, does not produce the required heat effect." In other words, with gas-firing, higher and more uni- form temperatures may be obtained when a low-grade fuel is gasified than when it is burned direct. 248. Objections. " The objections made to gas kilns such as danger of ex- plosions, greater cost of construction, obstruction of conduits by tar, more expensive firing, etc. have very little, if any, foundation. But to succeed in using them carefully, well trained workmen are required who are capable of ensuring a steady and uniform working of the producer; there lies the whole secret of success." (B 126.) 249. Difficulties in using producer-gas. One of the first difficulties in the use of producer-gas is that, since the products of combustion are different from those of solid fuels, it is not possible to secure comparable results where the workman attempts to judge the degree or intensity of burning by observing the color of the finished product, as seen through the products of combustion. When a heated brick or other object is observed through this atmosphere, the shade of color appears very different from similar objects, at the same tempera- ture and color, when observed through an atmosphere composed of the products of combustion of a solid fuel. This fact has been the cause of several failures where good coal burners have not been able to succeed with gas. It is evident that this trouble is not the fault of producer-gas, but rather the inability of the workman to interpret the results obtained, and it may easily be eliminated either by teaching the workman how to observe PRODUCER-GAS FOR FIRING CERAMIC KILNS. 199 the correct color and corresponding temperature or by control- ling that point by means of a reliable pyrometer. The regulation of the air supply especially in burning brick has often given trouble; this feature is discussed as follows by Davis (B 48), with reference to natural gas, but the same difficulties have frequently been experienced with pro- ducer-gas : "If from any cause there is a disproportion between the gas and the air, the brick will be injured, as we shall see in relation to water-smoking and the early stage of firing. In water-smok- ing with gas, the process will require a longer period than, with solid fuel in order to preserve the brick in their natural color and original form. If haste is attempted, the gas will not be thoroughly consumed and the oxygen taking up the hydrogen frees the carbon, which, being in minute particles, seems to enter the pores of the clay and discolor the brick. When the kiln becomes hotter, these particles are consumed and act as if bitu- minous coal dust had been mixed with the clay." The tar in the gas made from soft coal will frequently give more or less trouble by clogging valves, dampers, and conduits, or by discoloring the articles being burned in the kiln. The easiest solution for this is to so design the producer as to require the gas to pass through a mass of incandescent coke and in this way break up the tar into non-condensible compounds. Scrub- bing the gas would remove the trouble but would usually ab- stract the larger part of the sensible heat of the gas. It is almost impossible to secure the ignition of producer-gas in a cold chamber and with cold air. For this reason it has usually been difficult to water-smoke brick with producer-gas, and in its place wood is often used for this preliminary heating. A type of kiln in which the air is pre-heated is always desirable for the utilization of producer-gas; the effect of pre-heating is discussed in 109, 112, and 113. 250. Heat losses. The non-cooling of the gas in traveling from the producer to the kiln is of vital importance and is ably discussed by Professor Orton (B 142) : " In the producer, we perform the first reaction, burning the carbon substantially to CO. Of course there are numerous other side reactions taking place, but the gas produced 200 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. is essentially CO, and still contains locked up 10,050 B. t. u. per pound of carbon contained. We may then carry this pound of carbon in the form of producer-gas to the point where we wish to burn it, and there liberate the remaining 10,050 B. t. u. If the gas is cooled down to atmospheric temperature, it means a loss of 4450 B. t. u. out of 14,500 a heavy proportion to pay for the advantage of producer-gas. If the producer is located a long distance from the kilns so that the gas reaches them cool, you lose substantially thirty per cent of the heat contained in the fuel. On the other hand, if the producer is located very close, you may greatly reduce the loss of the 4450 heat units given off in mak- ing the gas; a large part may remain in the gas as sensible heat, and these heat units may be carried by the gas directly into the kiln where the remaining heat units are given off when the gas meets the air. Therefore, if you are using gas hot from the producer, and throwing it into the zone of combustion with comparatively little cooling off, there is no great loss of efficiency in using coal in this form. In a gas-producer process this point should be carefully studied. The efficiency of the producer depends on using the gas from the producer at as small a distance as possible, and the utmost pains should be taken to prevent cooling down of the gas before it reaches the scene of its final combustion." The loss of 30 per cent mentioned in the preceding paragraph may be reduced to at least 15 per cent by the use of steam in the producer, as discussed in Chapter 8. At Mt. Savage, Mary- land, where the gas is used for heating a continuous brick kiln, a unique arrangement has been worked out to reduce the sen- sible heat loss in the gas. " The producer is portable, and moves on wheels on a track along the side of the kiln on the side oppo- site to the main flue. The idea of having the producer portable is that, by being able to move it to successive chambers, the gases are still hot when they enter the kiln and ignite more readily than if conveyed through flues or pipes from a stationary pro- ducer." (B 142.) 251. Effect of solid fuel constituents. This point has been discussed thoroughly by Seger (B 160). "From the very start a correct conception of the effects which the separate constituents of the gas exert has not been had , and PRODUCER-GAS FOR FIRING CERAMIC KILNS. 201 it has been believed that if only the ash is removed all discolor- ing influences are done away with also. But has really the quality of the fuel been changed by gasification? Is there not present the same quantity of steam, volatile sulphur compounds, ammonium salts, alkali vapors, and perhaps other impurities which are present when the low-grade fuel is burnt on a grate? And are not the constituents mentioned those which exert the most injurious effects owing to violent chemical reaction and hence are to be feared more than the ash? These constituents cause the difference between the flames of fossil fuels and wood. The chemical reactions of the flame, and especially the volatile impurities, exert exactly the same influence whether the low- grade and impure fuel is burnt in the form of producer-gas or by direct combustion; in fact, the effect is stronger with the gas, as has been shown by practice and of which I have convinced myself by corresponding experiments. I believe that satisfac- tory results will be obtained with gas-firing only when it is pos- sible to produce gas from low-grade fuel, removing from the former the injurious constituents before introducing the gas into the kiln." It must be understood, however, that the limitations made by Seger in the preceding paragraph are not of universal applica- tion, but are effective only where the constituents of the gas would have a deleterious effect on the quality of the particular ceramic product under treatment. 252. Advantages of producer-gas. 1. With regeneration appliances, an unlimited intensity may be obtained, and the combustion of the gas is under complete control. 2. The mildness of the gas flames will insure the best results for the ceramic product under treatment, "since a mild and diffused heat is preferable to an intense local heat in the arches and decreases every course away from them." 3. "It may be produced from the cheaper grades of fuel, and makes more available heat than is possible with the costliest fuel used in the ordinary grate." 4. No more skilled labor required than with grates, the ten- dency being to decrease this. 5. Centralization of furnaces, thereby making it easier to handle fuel by mechanical appliances. 202 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. 6. Elimination of clinkering in kiln, thereby decreasing the heat losses and wear on the kiln. 7. Steady maintenance of a uniform heat. 8. More uniform burning. 9. Better combustion; this is discussed in detail by Orton (B 142). "Another source of economy lies in the fact that it is possible to approximate much more closely to the theoretical perfect combustion. To burn a pound of coal requires, as we know, about eleven pounds of air speaking in averages - FIG. 87. SECTION OF GAS-PRODUCER FOR KILN. yet we often use twenty-two or thirty-three pounds, or even fifty-five pounds of air per pound of coal in actual operation. An excess of 300 per cent of the theoretical amount of air re- quired is not uncommon." "With the use of producer-gas, it is quite safely possible to cut down the excess of air in cases where it is the intention merely to consider the efficiency of heat production. In clay burning the chemical condition of the atmosphere is often most impor- tant, and all questions of fuel economy must be considered as secondary to this. But it is possible in the use of gas to limit PRODUCER-GAS FOR FIRING CERAMIC KILNS. 203 the excess of air very much more than with solid fuel, while still maintaining an oxidizing fire, and consequently there is much less heat carried out as sensible heat of the waste gases, and so economy may come in that way." 253. Types of gas-producers for ceramic work. The producer shown in Fig. 87 is an integral part of the kiln proper. A is the charging door; B is an inclined grate over ash OW)j^& J! o Vapor Air, Ibs. Vapor, Mixture pounds 0) 03 ^^L -U^ ^ J'o Inches o pounds pounds WHH Mercury A B c D E F G H .0864 .044 29.877 .0863 .000079 .086379 .00092 12 .0842 .074 29.849 .0840 .000130 .084130 .00155 22 .0824 .118 29.803 .0821 .000202 .082302 .00245 32 .0807 .181 29.740 .0802 .000304 .080504 .00379 42 .0791 .267 29.654 .0784 .000440 .078840 .00561 52 .0776 .388 29.533 .0766 .000627 .077227 .00819 62 .0761 .556 29.365 .0747 .000881 .075581 .01179 72 .0747 .785 29.136 .0727 .001221 .073921 .01680 82 .0733 1.092 28.829 .0706 .001667 .072267 .02361 92 .0720 1.501 28.420 .0684 .002250 .070717 .03289 102 .0707 2.036 27.885 .0659 .002997 .068897 .04547 112 .0694 2.731 27.190 .0631 .003946 .067046 .06253 122 .0682 3.621 26.300 .0599 .005142 .065042 .08584 132 .0671 4.752 25.169 .0564 .006639 .063039 .11771 142 .0660 6.165 23.756 .0524 .008473 .060873 .16170 152 .0649 7.930 21.991 .0477 .010716 .058416 .22465 162 .0638 10.099 19.822 .0423 .013415 .055715 .31713 172 .0628 12.758 17.163 .0360 .016682 .052682 .46338 182 .0618 15.960 13.961 .0288 .020536 .049336 .71300 192 .0609 19.828 10.093 .0205 .025142 .045642 1.22643 202 .0600 24.450 5.471 .0109 .030545 .041445 2.80230 212 .0591 29.921 0.000 .0000 .036820 .036820 Infinite. 267 268 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. TABLE 12. (KENT.) RELATIVE HUMIDITY OF AIR, PER CENT. 32 40 50 60 70 80 90 100 110 120 140 Difference between the Dry and Wet Thermometers, Degree F. 7 8 9 I0|ll|l2|l3|l4|l5|l6|l7|l8|l9|2o|2l|22|2324|262830 Relative Humidity, Saturation being 100 401 Jl 1 21 1 121 31 76;68|60l534538 ! 3022 ! t .- 1 -_ I -^ 1 _. 93187:807467 61 94898478736863 95190868177726864 837975726864 7S 96|92 88 85 81 97939086838077 97 94 90 87 84 81 97 94,91 88 85 83 80 97 95'92 89 87 84 82:79 77 55 50 44 38 33 27 22 5S 53 48 44 39 34 7571 74 78:76737067 68 65 62 59 56:53 50 47^4 41 39 30 34 32 29;26 22 17 57 54 51 47 30 26 22 605552 484440361332926 68651625957 6562 75 72 70;67:65 62 60 58 56 54 ti05 18 14 10 23 19 16|13 101 7 44141 38 3532 29 2623 20i 18 3 51 49 47 44 42 39 37 35|33'29 25 21 55 53 50 48 46 44 42 40 38'34 30 27 .58 56 54 51 49 47.45 44,42 38 35 31 75 73|71|68 66 64162,60 58i56|55i53|51 49|48|44 41 38 TABLE 13. (FROM SUPLEE.) COEFFICIENTS OF RADIATION. B. t. u. per 1 degree F., pel Surface square foot, per hour Silver, polished 02657 Copper, polished 03270 Tin, polished 04395 Tinned iron, polished 08585 Iron, sheet, polished 0920 Iron, ordinary 5662 Glass 5948 Cast iron, new 6480 Cast iron, rusted 6868 Sawdust 7215 Sand, fine 7400 Water 1.0853 Oil 1.4800 TABLE 14. (FROM SUPLEE.) RADIATION RATIOS. Difference in tempera- ture, Fahr. Degrees Ratio Difference in tempera- ture, Fahr. Degrees Ratio Difference in tempera- ture, Fahr. Degrees Ratio 10 .15 160 .61 310 2.34 20 .18 170 .65 320 2.40 30 .20 180 .68 330 2.47 40 .23 190 .73 340 2.54 50 .25 200 .78 350 2.60 60 .27 210 .82 360 2.68 70 .32 220 .86 370 2.77 80 .35 230 .90 380 2.84 90 .38 240 1.95 390 2.93 100 .40 250 2.00 400 3.02 110 .44 260 2.05 410 3.10 120 .47 270 2.10 420 3.20 130 .50 280 2.16 430 3.30 140 1.54 290 2.21 440 3.40 150 1.57 300 2.27 450 3.50 For use of this table see 27. REFERENCE DATA. 269 TABLE 15. RADIATION LOSS IN IRON PIPES. (FROM SUPLEE.) Units of heat (B. t. u.) emitted, per square foot, per hr. Mean tem- Temperature of air = 70 degrees F. perature of pipes, Fahr. degrees By convection By radiation SiloilG By convection and radiation combined Air still Air moving Air still Air moving 80 5.04 8.40 7.43 12.47 15.83 90 11.84 19.73 15.31 27.15 35.04 100 19.53 32.55 23.47 43.00 56.02 110 27.86 46.43 31.93 57.79 78.36 120 36.66 61.10 40.82 77.48 101.92 130 45.90 76.50 50.00 95.90 126.50 140 55.51 92.52 59.63 115.14 152.15 150 65.45 109.18 69.69 135.14 178.87 160 75.68 126.13 80.19 155.87 206.32 170 86.18 143.30 91.12 177.30 234.42 180 96.93 161.55 102.50 199.43 264.05 190 107.90 179.83 114.45 222.35 294.28 200 119.13 198.55 127.00 246.13 325.55 210 130.49 217.48 139.96 270.49 357.48 220 142.20 237.00 155.27 297.47 392.27 230 153.95 256.58 169.56 323.51 426.14 240 165.90 279.83 184.58 350.48 464.41 250 178.00 296.66 200.18 378.18 496.84 260 189.90 316.50 214.36 404.26 530.86 270 202.70 337.83 233.42 436.12 571.25 280 215.30 358.85 251.21 466.51 610.06 290 228.55 380.91 267.73 496.28 648.64 300 240.85 401.41 279.12 519.97 680.53 For use of this table see 27. TABLE 16. RADIATION LOSS THROUGH WALLS. (FROM SUPLEE.) LOSS, IN BRITISH THERMAL UNITS, PER SQUARE FOOT, PER HOUR, FOR 1 DEGREE F. DIFFERENCE. Thickness in inches Brick Stone Thickness in inches Brick Stone 4 8 12 16 20 .273 .223 .188 .163 .144 .330 .312 .295 .280 .267 24 28 32 36 40 .129 .116 .106 .097 .090 .255 .244 .234 .224 .216 For use of this table see 27. 270 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. TABLE 17. EFFICIENCY OF PIPE COVERINGS. (TRANS. A. S. M. E., VOL. VI, P. 168. Substance 1 in. thick Heat applied, 310 deg. F. British thermal units per sq. ft. per minute Solid matter in 1 sq. ft. 1 in. thick, parts in 1000 Air included, parts in 1000 1. Loose wool 2 Live-geese feathers 1.35 1 60 56 50 944 950 3 Loose lampblack 1 63 56 944 4 Hair felt 1 72 185 815 5 Carded cotton wool 1 73 20 980 6 Compressed lampblack . . 1 77 244 756 7 Cork charcoal 1 98 53 947 8 Loose calcined magnesia 207 23 977 9. Best slag-wool 10. Light carbonate of magnesia 1 1 . White-pine charcoal 12 Paper 2.17 2.28 2.32 2 33 60 119 940 881 13 Loose fossil-meal 2 42 60 Q40 14 Cork strips bound on 2 43 15. Compressed carb. of magnesia 16. Crowded fossil-meal 17. Paste of fossil-meal with hair 18. Straw rope wound spirally 19. Loose rice chaff 2.57 2.62 2.78 3.00 3 12 150 112 850 888 20. Ground chalk (Paris white) 343 253 747 21. Loose bituminous-coal ashes 350 22. Blotting-paper wound tight 350 23. Asbestos paper wound tight 24. Paste of fossil-meal with asbestos 25. Loose anthracite-coal ashes 26. Paste of clay and vegetable fiber. . . 27. Dry plaster of paris 28. Anthracite-coal powder 3.62 3.67 4.50 5.15 5.15 595 368 506 632 494 29. Compressed calcined magnesia 30. Air alone 7.10 800 285 o 715 1000 31. Fine asbestos 8 17 81 919 32. Sand 10 35 529 471 REFERENCE DATA 271 TABLE 18. (R. D. WOOD & Co.) DISCHARGES OF GAS, IN CUBIC FEET PER HOUR, THROUGH PIPES OF VARIOUS DIAMETERS AND LENGTHS, AND AT DIFFERENT PRESSURES OF WATER, IN INCHES. These results must be applied with care. No allowance is made in the tables for obstructions in the pipes. For every right-angle bend add iV inch to the pressure of water. The use of this table may be extended by the application of the following laws: 1. The discharge of gas will be doubled when the length of the pipe is only one-fourth of any of the lengths given in the table. 2. The discharge of gas will be only one-half when the length of the pipe is four times greater than the lengths given in the table. 3. The discharge of gas is doubled by the application of four times the pressure. SPECIFIC GRAVITY .4 ; SEE 28. 1^ IN. DIAMETER 2 IN. DIAMETER 3 IN. DIAMETER Lengths of PRESSURES Pressures Pressures in Yards 1. 1.5 2. | 2.5 1. | 1.5 2. | 2.5 1. 1.5 2. 2.5 Discharges Discharges Discharges 100 588 720 832 932 1208 1480 1708 1908 3100 4075 4700 5260 150 478 588 680 759 986 1208 1394 1560 2718 3329 3840 4293 200 416 509 590 655 853 1046 1208 1350 2350 2881 3328 3718 300 351 420 478 537 697 853 984 1103 1920 2353 2714 3037 500 263 323 372 416 540 661 762 853 1488 1823 2108 2353 750 215 263 304 340 441 540 624 697 1216 1488 1718 1920 1000 186 228 284 294 381 468 540 534 1054 1289 1488 1644 1250 166 204 236 263 342 419 484 540 942 1155 1332 1354 1500 152 186 215 240 312 381 442 493 859 1052 1216 1357 1750 141 172 199 223 280 353 408 457 795 974 1130 1279 2000 132 161 186 208 270 331 381 427 744 912 1054 1176 4 IN. DIAMETER 6 IN. DIAMETER 8 IN. DIAMETER 100 6831 8370 9658 10800 18820 23 050 26600 29 770 38 650 47 350 54640 61 100 150 5580 6830 7888 8817 15 370 18 820 21 700 24 300 31 550 38640 44600 49940 200 4829 5920 6826 7674 13310 16400 18800 21 000 27 340 33 460 38 600 43 200 300 3944 4829 5577 6233 10 870 13 310 15 370 17 180 22 310i27 340 31 550 35 270 500 3055 3740 4320 4829 8418 10310 11 940 13 310 1728021 17024400;27340 750 2420 3055 3522 3944 6872 8418 9720 10870 14 100 17 280 19800 22310 1000 2160 2646 3052 3413 5950 7290 8420 9410 12 220 14960 17280 19320 1250 1932 2366 2732 3052 4340 5320 7540 8415 10940 13650 15520 17280 1500 1761 2160 2490 2789 4860 5970 6860 7672 9900 12 200 14040 15800 1750 1634 2000 2310 2582 4500 5500 6360 7115 9237 11 300 13040 14600 2000 1530 1870 2150 2415 4209 5155 5970 6655 8640 10585 12 200 13670 272 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. > M O O O O O O 10 3; cc O r- X :; 000 c c c o S2 C-) O O iO S2 < - " ! CC SO O O OO ^ OO O C "5 OC CC O O O C<1 OO O5 o --s p co o M OOOOOtC-HO oosiooocooo <-Cl-H^CO>O^HOf-. ,-,____ GOO 8888 O f e^t o<-i^ooco Ot^-*O5OCOOCo 04 O O OC 3C - oooo -< t~- 5C t^- IM C< < * O C^llO t^ CO S (^ iO-* COCO! * oo o e^i r^ r^ *< < I^ CC O CO OC iC CO ! ITS Tf *< co e^i o e^ < REFERENCE DATA. 273 ! 274 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. iJ O < i saqDui m adij nreui jo" jajauiBiQ w 22 815 REFERENCE DATA. 275 TABLE 20. SOLUBILITY OF VARIOUS GASES IN WATER One volume of water at 20 deg. C. absorbs the following volumes of gas reduced to deg. C. and 760 mm. pressure Name of gas Symbol Volumes Carbonic oxide Carbon dioxide CO CO 2 0.023 901 Hydrogen H, 01Q Methane CH 4 035 Nitrogen N 014 Oxvffen O 2 0028 Air 017 TABLE 21. MELTING-POINTS OF VARIOUS METALS AND SALTS (FROM CARNELLY MELTING- AND BOILING-POINT TABLES.) Alphabetically By Temperatures Aluminum Antimony Deg. C. .. 660 432 Tin Deg. C. . . . 233 . . . 268 320 Bismuth Barium chloride 860 Cadmium . Bismuth Calcium fluoride Cadmium Cadmium chloride '. . 268 . . 902 . . 320 541 Lead 334 Antimony 432 Zinc Cadmium chloride . . . 433 54 1 Copper 1095 Aluminum 660 Lead .. 334 .. 734 772 Potassium chloride Sodium chloride Barium chloride . . . 734 . . . 772 860 Potassium chloride Sodium chloride Tin 233 Calcium chloride 902 Zinc . . 433 Copper . .. 1095 TABLE 22. VARIATION IN THE VOLUMETRIC SPECIFIC HEAT OF CARBONIC ACID. SEE 20. The following table was calculated by Professor Akerman (B 67). The specific heat is in calories per cubic meter, and for each temperature the figure represents the mean value of the specific heat at constant pressure between degrees C. and t degrees C. Specific heat 400 467 500. . 600.. 700.. 800. .487 .507 .525 .544 900. . .562 1000. 1100. 1200. .580 .598 .615 276 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. FUEL DATA. COAL. A bushel of bituminous coal weighs 76 pounds (Pennsylvania) and contains 1.554 cubic feet; in Ohio and West Virginia the weight is 80 Ib. 41 to 45 cubic feet bituminous coal = 1 ton, 2240 Ib. 34 to 41 cubic feet anthracite coal = l ton, 2240 Ib. CHARCOAL. A bushel of charcoal weighs 20 Ib. and contains 2748 cu. in. 123 cubic feet charcoal = 1 ton, 2240 Ib. COKE. A bushel of coke weighs 40 Ib. 70.9 cubic feet coke = 1 ton, 2240 Ib. WOOD. 2J Ib. of dry wood=l Ib. of coal. COMPOSITION OF WOOD. Average Oak, 120 yrs. Birch, 60 yrs. Willow Carbon 50 50.97 50.59 51.25 Hydrogen 6 6.02 6.21 6.19 Oxygen 41 41.96 42.16 41 98 Nitrogen 2 1.27 1.01 .98 Ash . . 2 1.93 2.1 3.67 The calorific value of dry wood is about 7000 B. t. u. and of air-dried wood about 5600 B. t. u. The calorific intensity is very low. Ordinary firewood contains, by analysis, from 27 to 80 per cent of hygrometric moisture. 1 cord of hickory or maple weighs 4500 Ib. 1 cord of white oak weighs 3850 Ib. 1 cord of beech, red oak, or black oak weighs 3250 Ib. 1 cord of poplar, chestnut, or elm weighs 2350 Ib. 1 cord of average pine weighs 2000 Ib. A cord of wood = 4X4X8 = 128 cu. ft. = about 56 per cent solid wood and 44 per cent interstitial spaces. CHAPTER XXX. BIBLIOGRAPHY OP GAS-PRODUCERS. The following abbreviations have been used in the text: A. d. mines, Annales des mines. Gassier' s, Gassier 's Magazine. Eng. and Min. Jour., The Engineering and Mining Journal. Eng. Lond., The Engineer (London). Eng. Mag., Engineering Magazine. Eng. News, Engineering News. Eng. Rec., Engineering Record. Engng., Engineering. Engr., The Engineer (Chicago). Gasmt., Die Gasmotorentechnik. I. C. T. R., Iron and Coal Trades Review. Iron S. M., Iron and Steel Magazine. J.I. and S. I., Journal of the Iron and Steel Institute. Jour. F. I., Journal of the Franklin Institute. Jour. Assn. Eng. Soc., Journal of the Association of Engineering Societies. J. S. C. I., Journal Society Chemical Industry. Mar. Eng., Marine Engineering. Mem. Soc. Ing. Civ., France, Memoires de la Societe des Ingenieurs Civils, France. N. B. M. A. National Brick Manufacturers Association report. Prac. Eng., Practical Engineer (London). Proc. Engs. Soc. of W. Pa., Proceedings of the Engineers' Society of Western Pennsylvania. Proc. I. C. E., Proceedings of the Institute of Civil Engineers. Proc. I. M. E., Proceedings of the Institution of Mechanical Engineers. Sci. Am., Scientific American. Sci. Am. Sup., Scientific American Supplement. Trans. A. I. M. E., Transactions of the American Institute Mining Engineers. Trans. A. C. S., Transactions American Ceramic Society. Trans. A. S. M. E., Transactions American Society Mechanical Engineers. Zeitschr. d. V. D. Ing., Zeitschrift des Vereines Deutscher Ingenieure. CHRONOLOGICAL ARRANGEMENT. 1841. B 1. A. d. mines, Vol. IV, p. 436. Reference to the value of the use of steam in gas-producers. B 2. A.d. mines, Vol. XX, p. 463. Illustration of Ebelmen gas-producer. 1843. B 3. A. d. mines, Vol. Ill, p. 210. Illustration of Ebelmen gas-producer. B 4. A. d. mines, Vol. Ill, p. 222. Illustration of Ebelmen gas-producer. B 5. A.d. mines, Vol. Ill, p. 225 and 258. Discussion of the effect of steam in gas-producers. 1857. B 6. Proc. I. M. E., p. 103. Discussion of a gas furnace for the develop- ment of intense heat. 277 278 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. 1862. B 7. Proc. I. M. E., p. 21. Discussion of regenerative furnaces. 1866. B 8. Mem. Soc. Ing. Civ., France, p. 585. Complete description of the Beaufume producer. B 9. Transactions of the Institute of Engineers in Scotland, Vol. I, p. 14. General description of the Beaufume producer. 1868. B 10. Journal of the Chemical Society (London), Vol. XXII, p. 293. Dis- cussion of the Siemens producer. 1869. B 11. Manufacture of Iron and Steel, by F. Kohn, p. 132. Discussion and illustration of the Siemens gas-producer. 1872. B 12. Proc. I. M. E., p. 97. Extensive discussion of steam jets and blowers; gives several illustrations. 1874. B 13. Mem. Soc. Ing. Civ. France, p. 678. Results obtained with Ebelmen's producer. 18?5 B 14. Percy's Metallurgy, volume on Fuel, p. 532. Discusses gaseous fuel. B 15. Percy's Metallurgy, volume on Fuel, p. 517. Description of Ekman and Wedding producers. B 16. Percy's Metallurgy, volume on Iron and Steel, p. 463. Discussion of waste heat. 187g B 17. Etudes sur les Combustibles, by M. Lencauchez. Extensive treatise devoted to the gasification of fuel and the applications of fuel gas. Gives plates with exceptionally good illustrations. 1879. B 18. Combustion of Coal, by W. M. Barr, p. 128. Discusses the pre-heat- ing of air. B 19. Fuel, its Combustion and Economy, by Clark, p. 282. Discusses gas furnaces and gas-producers, decomposition of fuel in gas- producers, and gives summary of results obtained by Ebelmen. 1880. B 20. Trans. A. I. M. E., Vol. VIII, p. 27. General description, with good illustration of the Tessie producer. B 21. Trans. A. I. M. E., Vol. VIII, p. 289. Discussion of the Strong gas system. B 22. Treatise on Fuel, by R. Galloway, p. 86. Description of Siemens gas-producer. 1881 B 23. Gasfeuerung und Gasofen, by H. Stegmann. Numerous references to the use of producer-gas in the ceramic industry. B 24. Trans. A. I. M. E., Vol. IX, p. 309. Discussion of a fluxing gas- producer. B 25. Trans. A. I. M. E.,.Vol. IX, p. 310. Discussion of gas-producers using blast, and good illustrations of Swedish types for using wood. B 26. Zeitschrift fur physikalische Chemie, Vol. II, p. 161. Extensive dis- cussion of the action in a gas-producer. 1883. B 27. Eng. News, December 1st. Discusses invention of gas, and gives early history. BIBLIOGRAPHY OF GAS-PRODUCERS. 279 B 28. J. S. C. I., Vol. II, p. 62. Discusses the economical use of fuel. B 29. J. S. C. I., Vol. II, p. 453. Discussion of the Wilson gas-producer and the recovery of by-products. B 30. J. S. C. I., Vol. II, p. 504. Extensive discussion of the advantages of gaseous fuel. B 31. Proc. I. C. E., Vol. LXXIII, p. 311. Discussion of producer-gas for motive power, with several illustrations. B 32. Trans. A. I. M. E., Vol. XI, p.. 292. Discussion of analysis of fur- nace gases. 1884. B 33. Handbuch der Eisenhiittenkunde, by Ledebur. Numerous refer- ences to the use of and value of fuel gas to the iron industry. B 34. J. I. and S. I., Vol. I, p. 72. Utilization of gaseous fuel; description, with illustration, of producer and scrubber. B 35. Trans. A. I. M. E., Vol. XII, p. 93. Illustration and general descrip- tion of Langdon gas-producer. 1885. B 36. Engng., October 30th. Discussion of water-gas production. B 37. J. I. and S. I., Vol. I, p. 126. General description and good illustra- tion of modified form of Siemens producer. B 38. J. S. C. I., Vol. IV, p. 439. Extensive discussion of flame action, and production of gas in Siemens modified producer. 1886. B 39. Proc. I. C. E., Vol. LXXXIV, p. 4. Classification, historical data; illustrates various forms of producers and gives extensive table showing the gas analyses from fifty-seven different producers. 1887. B 40. Coal tar and Ammonia, by G. Lunge. Numerous references to the extraction of tar and ammonia from gas. B 41. Elements of Metallurgy by J. A. Phillips, p. 98. Discussion of Sie- mens gas-producer. B 42. Feuerungskunde, by Ludwig Ramdohr, p. 78. Thorough discussion of the gasification of fuel. 1888. B 43. J. I. and S. I., Vol. I, p. 86. Extensive discussion of the use of water gas and producer-gas for metallurgical purposes. 1889. B 44. Chemical Technology, by Groves and Thorpe, Vol. I, p. 250. General discussion of foreign gas-producers. B 45. J. I. and S. I., Vol. II, p. 139. General discussion of gaseous fuel. B 46. J. I. and S. I., Vol. II, p. 256. Description and illustrations of a Siemens furnace arranged to recover waste gases. B 47. J. S. C. I., Vol. VIII, p. 503. Description and illustration of Mond gas plant. B 48. Practical Treatise on Manufacturing Bricks, by C. T. Davis, p. 246. Discussion of the use of gas in burning brick. 1890. B 49. Eng. News, Vol. XXIV, p. 317. Discussion of fuel gas, giving illus- tration of the Loomis system. B 50. Les Moteurs a Gaz et les Moteurs a Petrole, by C. Wehrlin, p. 61. Gives illustration of a gas-producer. B 51. Trans. A. I. M. E., Vol. XVIII, p. 609. Notes on fuel gas. B 52. Trans. A. I. M. E., Vol. XVIII, p. 859. Thorough discussion of the energy, utilization, and gasification of fuel. 280 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. 1891. B 53. Clay Worker, May 15, p. 499. Brief discussion of the production of gas. B 54. Clay Worker, June 15, p. 596. Brief discussion of gaseous fuel. B 55. Clay Worker, July 15, p. 25. Brief discussion of the physics of gaseous fuels. B 56. Dictionary of Applied Chemistry, by Thorpe, Vol. II, p. 217. Brief discussion of producer-gas. B 57. Eng. and Min. Jour., Vol. LI, May 9, p. 562. Description of producer plant for roasting-kilns; gives summary of fuel consumption. B 58. Eng. News, Vol. XXV, p. 512 and 521. Discussion of fuel gas. p. I, B 59. Eng. News, Vol. XXVI, p. 329. Discussion of the gasification of anthracite. B 60. Gasfeuerungen by Ledebur. Numerous references to producer-gas and the manufacture of same. B 61. Jour. F. I., Vol. CXXXII, p. 424. Fuel gas; its production and distri- bution. B 62. J. I. and S. I., Vol. II, p. 104. Description of a Thwaite gas plant, giving several drawings. B 63. Moteurs a Gaz, by Gustave Chauveau, p. 275. Brief description of gas-producers. B 64. N. B. M. A., p. 134. Extensive discussion of the use of producer-gas for burning brick. B 65. Proc. I. M. E., p. 47. Extensive discussion of gas furnaces; gives sixty-three illustrations. B 66. Trans. A. I. M. E., Vol. XIX, p. 128. Physical and chemical equa- tions; gives thorough discussion of the chemistry of a gas-pro- ducer, with numerous tables. 1892. B 67. Berg- und Huttenmannisches Jahrbuch der k. k. Bergakademien, Vol. XL, p. 81-203. German translation of Prof. R. Akerman's paper on gaseous fuel; discusses gas-production in detail and gives drawings of seven wood producers. B 68. Chemical Technology, by Rudolf Wagner, translated by Crookes, p. 41. Brief description and illustration of the Liirmann, Boetius and Siemens gas-producers. B 69. Eng. News, Vol. I, p. 540. Gives history of fuel gas; also discusses manufacture of water gas and producer-gas. B 70. School of Mines Quarterly, Vol. XIII, No. 2. The valuation of fuel gas; discusses method of determination. B 71. Trait6 des Moteurs a Gaz, by A. Witz, Vol. I, p. 115. Brief descrip- tion of gas-producers. B 72. Trans. A. I. M. E., Vol. XX, p. 635. Discussion of the mechanical effects of steam on the gas-producer. 1893. B 73. N. B. M. A., p. 151. Discussion of the use of producer-gas for bum- ing brick. B 74. Proc. Engs. Soc. of W. Pa., Vol. IX, p. 184 and 237. Gas-producers for metallurgical work. B 75. Proc. I. C. E., Vol. CXII, p. 2. Discussion of gas power for electric lighting. B 76. Trans. A. I. M. E., Vol. XXIII, p. 134 and 585. Discussion of fuel consumption in a Taylor producer. B 77. Trans. A. I. M. E., Vol. XXII, p. 371. Description and illustration of Wellman gas-producer, with discussion of manufacture of producer-gas. BIBLIOGRAPHY OF GAS-PRODUCERS. 281 1894. B 78. Cassier's, December, p. 123. Gas-producers for boilers. B 79. Eng. and Min. Jour., May 12th. Illustration and description of a Dauber gas-producer. B 80. Jour. F. I., November, p. 321. Description of the American Gas- Furnace Co.'s system of fuel-gas production. B 81. Trans. A. I. M. E., Vol. XXIV, p. 289. Description and illustrations of Swedish gas-producers for coal and wood. B 82. Trans. A. I. M. E., Vol. XXIV, p. 573. Brief notes on a Taylor gas- producer. B 83. Zeitschr. d. V. D. Ing., November 10th. Brief discussion of the theo- retical and practical problems involved with producer-gas. 1895. B 84. Eng. Lond., July 5th. Discussion of the Thwaite system of gas power. B 85. Iron Age, March 14th. Description and illustration of Kitson pro- ducer, with discussion of fuel gas. B 86. Zeitschr. d. V. D. Ing., December 21st and 28th. Full details of the test of a producer-gas power plant; gives summary of results. 1896. B 87. Colliery Guardian, March 27th. Discussion of history and efficiency of gas-producers. B 88. Eng. Lond., August 28th. Discussion of a Thwaite gas plant. B 89. Eng. Mag., Vol. XI, p. 905. The important features of producer-gas. B 90. Iron Age, April 30th. Description and illustration of Kitson producer. B 91. Jour. Assn. Eng. Soc., Vol. XVII, p. 169. Brief discussion of gas- producers. B 92. Manufacture and Properties of Structural Steel, by H. H. Campbell, p. 95 and 117. Brief reference to producer-gas. B 93. Prac. Eng., Vol. XIII, p. 666. Discusses fundamental principles of gas-producers. B 94. Prac. Eng., Vol. XIV, p. 112. Discusses efficiency and forms of gas- producers. B 95. Prac. Eng., Vol. XIV, p. 149. Discusses steam blowers for gas- producers. B 96. Prac. Eng., Vol. XIV, p. 174. Describes various English types of gas-producers. B 97. Prac. Eng., Vol. XIV, p. 251. Discusses tar, ammonia, and Mond gas. B 98. Prac. Eng., Vol. XIV, p. 294. Discusses regenerative furnaces. B 99. Proc. I. C. E., Vol. CXXIII, p. 328. Efficiencies of gas-producers; thorough discussion, with reports of several tests. B 100. The Gas and Oil Engine, by Dugald Clerk, p. 354. Discussion of producer-gas, with description of several types of producers. B 101. The "Otto" Cycle Gas Engine, by William Norris, p. 198. Descrip- tion of several gas plants. 1897. B 102. Eng. Lond., October 29th. Description of a Thwaite gas plant. B 103. Fuel, by Sexton, p. 139. Extensive discussion of producers and producer-gas. B 104. Iron Age, September 30th. Complete description of Kitson pro- ducer, with report of test. B 105. Practical Treatise on Modern Gas and Oil Engines, by Frederick Grover, p. 176. Application of producer-gas in engines. B 106. Proc. I. C. E., Vol. CXXIX, p. 190. Extensive discussion of Mond gas and its applications. B 107. Railroad Gazette, April 16th. Discussion of future fuel problem. B 108. J. S. C. I., Vol. XVI, p. 420. Comparison of gas-producers. 282 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. 1898. B 109., Eng. and Min. Jour., February 26th. Illustration and description of Kitson gas-producer. B 110. Electric Review (London), November llth. Report of test of gas- producer plant in Switzerland. B 111. Engng., September 23d. Description of Benier gas-producer. B 112. /. C. T. R., January 21st. Discussion of modern types of gas-pro- ducers. B113. N. B. M. A., p. 161. Brief discussion of the use of producer-gas for burning brick. B 114. Nineteenth Century, July. Discussion of future fuel supplies. B 115. O 'Conner's Gas Engineer's Pocket Book, p. 385. Brief discussion of the various systems of gas-production. B 116. Poole's Calorific Power of Fuels, p. 92. Discussion of gaseous fuels. B 117. Trans. A. I. M. E., Vol. XXVIII, p. 166. Illustrated description of an automatic feed-device for gas-producers. 1899. B 118. Colliery Guardian, July 14th. Economical use of fuel; shows how economy may and must be improved. B 119. Electric Review (London), July 28th. Discussion of a gas engine with 30 per cent efficiency. B 120. Gas World, September 9th. Discussion of the fuel problem of the future. B 121. Heat and Heat Engines, by Button, p. 60. Discussion of producers and producer-gas. B 122. J. S. C. I., Vol XVIII, p. 646. Discussion of gaseous fuels. B 123. Mineral Industry, Vol. VIII, p. 124. Economical utilization of fuel. B 124. Proceedings Cleveland institution of Engineers (England), March 16th. Discussion of the advantages of gas engines for general power purposes. B 125. Thorp's Outlines of Industrial Chemistry, p. 30. Brief discussion of producer-gas. B 126. Architectural Pottery, by Leon Lefevre, English translation by Bird and Binns, p. 231. Discussion of the use of gaseous fuel in continuous kilns. B 127. Brick, November 1st. Notes on the use of producer-gas in burning brick. B 128. Eng. and Min. Jour., Sept. 8th, p. 281. Describes method of mak- ing gas by the Riche system. B 129. Eng. and Min. Jour., October 20th, p. 460. Description and illus- trations of the Riche wood gas-producers. B 130. Eng. Mag., October. Discussion of the coal supply of the U.S. B 131. Engng., Vol. LXX, p. 169. Brief description of the Siemens, Gardie, Taylor, Benier, Kitson, Loomis, Wilson, Longston, Mond, Beure- Lencauchez, Dowson, and Pinkey gas-producers, the last named being illustrated. B 132. Engng., Vol. LXX, p. 202 and 203. Considerable tabulated data are given with regard to the operation of gas-power plants. B 133. Engng., Vol. LXX, p. 244. Valuable tabulated data are given on cost of gas-producer power plants. B 134. Engng., Vol. LXX, p. 399. Description and illustrations of a gas- producer plant in Switzerland. B 135. Engng., Vol. LXX, p. 526. Description and illustrations of a Fichet- Heurty gas-producer power plant. B 136. Engng., Vol. LXX, p. 589. Description with several illustrations of a Crossley gas-producer plant. B 137. Engng., Vol. LXX, p. 654. Description and illustrations of a Kort- ing gas-producer plant. BIBLIOGRAPHY OF GAS-PRODUCERS. 283 B 138. Engng., Vol. LXX, p. 811 and 845. Extensive discussion of the use of Mond gas; gives several illustrations. B 139. Gas, Oil and Air Engines, by Byran Donkin, p. 158. Extensive discussion of gas-production for motive power. B 140. Handbuch der Eisenhuttenkunde by Ledebur, p. 100. Thorough discussion of the use of producer-gas, with illustrations of pro- ducers. B 141. 7. C. T. R., July 20th. Discusses extent of coal fields at the close of the nineteenth century. B 142. Trans. A. C. S., p. 38. Notes on the use of producer-gas in burning brick. 1901. B 143. Dawsqn's Engineering and Electric Traction Book, p. 829. Dis- cussion of the manufacture of producer-gas, with several illus- trations of producer plants; also general data on scrubbers, gas holders, flame temperatures, and operating costs. B 144. Engng., Vol. LXXI, p. 41. Detailed description and illustration of the Duff by-product gas-producer plant. B 145. Eng. Lond., Vol. XCI, p. 287. Applications of Mond gas. B 146. Gluckauf, May llth. Description of power plant using lignites in producer. B 147. Gasmt., Vol. I, p. 106. Illustration and brief description of a suc- tion gas-producer plant. B 148. Iron Age, September 12th, p. 8. Report on the efficiency test of a gas-producer plant for heating furnaces. B 149. J. S. C. I., Vol. XX, p. 879. Brief description with illustration of gas-washer. B 150. Kent's Mechanical Engineer's Pocket Book, p. 646. Discusses fuel gas. B 151. Mem. Soc. Ing. Civ., France, September. Discusses the action of various types of gas-producers. B 152. Prac. Eng., Vol. XXIII, p. 58. Discussion of gas power. B 153. Prevention of Smoke, by W. C. Popplewell, p. 91. Brief discussion of gaseous fuel. B 154. Proc. I. C. E., Vol. CXLIV, p. 269. General discussion of producer- gas plants. B 155. Proc. I. M. E., p. 41 and 247. Extensive discussion of Mond gas. B 156. Stahl und Eisen, June 15th. Discussion of the use of lignites for making producer-gas. B 157. Treatise on Ceramic Industries, by Emile Bourry, English transla- tion by W. P. Rix, p. 336. Discussion of firing kilns with pro- ducer-gas. 1902. B 158. Cassier's, May, p. 48. Description of some representative gas-pro- ducer power plants for mining work. B 159. Cassier's, August, p. 500. General description of the method of making producer-gas. B 160. Collected Writings of H. A. Seger, edited by A. V. Bleininger, Vol. I, p. 316. Discussion of gas-fired kilns. B 161. Eisenhuttenkunde, by Wedding, Vol. II, p. 795. Brief discussion of producer-gas. B 162. Eng. Lond., Vol. XCIV, November 21st, p. 494. Description and illustration of Mond gas-producer. B 163 Gas and Petroleum Engines, by Robinson, p. 553. Discussion ot producer-gas. B 164. Gasmt., Vol. I, p. 167. Description and illustrations ot several suc- tion gas-producers. B 165. Gasmt., Vol. I, p. 188. Illustration and description of the Pmtscn patented gas regulator for suction gas-producers. 284 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. B 166. Gasmt., Vol. II, p. 97 and 121. Extensive discussion of the scrub- bing of gases. B 167. Gasmt., Vol. II, p. 119. Discussion of gas-producer power plants. B 168. Gas-Producer Catalogue of the R. D. Wood Co., Philadelphia, Pa. This is one of the best catalogues issued on the subject of gas- producers up to 1902; gives valuable data. B 169. Gas World, September 27th, p. 485. Description and illustration of Korting gas-producer. B 170. Genie Civil, April 25th. Illustration and description of a suction gas-producer. B 171. Iron Age, March 6th, p. 18. Discussion of steam blowers for gas- producers. B 172. J. S. C. I., Vol. XXI, p. 79. Brief discussion of the efficiency of a Wilson producer. B 173. I.C. T. R., October 17th. Gas-power station with Pintsch producer. B 174. Mem. Soc % Ing. Civ., France, June. Discussion of power gas. B 175. Mineral Industry, Vol. X, p. 167. Discusses the progress made in recent years. B 176. Prac. Eng., Vol. XXV, p. 440, 471, 487, 511. Extensive discussion of the applications of producer-gas. B 177. Stahl und Eisen, Vol. XXII, p. 1208. Discussion of the use of brown coal in producers. B 178. Thermodynamics of the Steam Engine, by Peabody, p. 214. Brief discussion of gas-producers. B 179. Transactions National Electric Light Association, May. General discussion of the advantages of gas engines for central station work; gives comparison with steam plant. B 180. Zeitschr. d. V. D. Ing., November 8th. Discussion of producers for engine work. 1903 B 181. American Gas-Light Journal, March 30th. Gas for industrial pur- poses. B 182. Braunkohle, p. 358 and 373. Discussion of the use of brown coal in producers. B 183. Bulletin de la Societe" de 1'Industrie Minerale, p. 889. Description of an experimental reversed combustion gas-producer, designed to work on fuels of low calorific value. B 184. Das Entwerfen und Berechnen der Verbrennungsmotoeren, by H. Giildner, p. 358. Illustrations and description of several German producers. B 185. Eng. Lond., December llth, Vol. XCVI, p. 578. Description and illustrations of the Crossley gas-producers. B 186. Engng., Vol. LXXV, June 5th, p. 761. Description and illustration of Taylor suction gas-producer. B 187. Engng., Vol. LXXVI, September 25th, p. 420. Description and excellent illustrations of a Pierson gas-producer plant. B 188. Engng., Vol. LXXVI, October 2d, p. 474. Description and illus- tration of Talbot mechanical gas-producer. B 189. Engng., Vol. LXXVI, November 20th, p. 696. Drawing and descrip- tion of Pierson gas-producer. B 190. Evaporating, Condensing, and Cooling Apparatus, by E. Hausbrand, translated by A. C. Wright. Numerous references to the cooling and condensing of gases. B 191. Gas World, April. Cheap gas for motive power. B 192. I. C. T. R., April 24th. Discussion of gas power. B 193. /. C. T. R., Vol. LXVI, p. 1644. Illustration and description of Duff producers and ammonia recovery plant. B 194. Iron, Steel, and Other Alloys, by H. M. Howe, p. 407. Discussion of metallurgical furnaces with special reference to gas regenera- tion. BIBLIOGRAPHY OF GAS-PRODUCERS. 285 B 195. J. I. and S. I., Vol. II, p. 582. Abstract of B 214. B 196. J. I. and S. I., Vol. II, p. 584. Abstract of article in B 215 B 197. Jour. Assn. Eng. Soc., October, Vol. XXXI, p. 89. Description and illustration of the methods of making coal and water gas, with illustrations of gas meters. B 198. Machinery (Engineering Edition), March 3d, p. 353. Brief descrip- tion and three illustrations of gas-producers. B 199. Materials of Machines, by Smith, p. 14. Brief description of the producer-gas process. B 200. Mechanical Engineer, April 4th. Discussion of the production of power by means of gas-producers and gas engines. B 201. Monograph on Mond Gas, by The R. D. Wood Co. Contains consider- able data and illustrations of general interest to the gas-producer industry. B 202. Power, April, p. 178. Illustration of suction producer. B 203. Power, April, p. 181. Producer-gas and gas engines. Illustration and description of Mond and Loomis producers. B 204. Power, September, p. 512. Brief description, with illustration, of a suction gas-producer. B 205. Prac. Eng., Vol. XXVII, p. 345. Brief discussion of gas-producers. B 206. Prac. Eng., Vol. XXVIII, p. 7. Illustrations and descriptions of recent forms of gas-producers. B 207. Proc. Eng. Soc. of W. Pa., Vol. XIX, p. 195. Extensive discussion of gas for power purposes. B 208. Proc. I. C. E., Vol. CLIV, p. 430. Abstract of article on a power gas plant in Switzerland; gives summary of results obtained. B 209. Proc. I. C. E., Vol. CLVI, p. 483. Abstract of article giving the sum- mary of the results obtained in testing a suction gas-producer plant. B 210. Proc. I. C. E., Vol. CLVI, p. 489. Abstract of article describing a reversed combustion gas-producer. B 211. Proc. I. C. E., Vol. CLVI, p. 578. Abstract of a description of a new gas-producer plant. B 212. Progressive Age, January 15th, p. 33. Description and illustrations of suction gas-producers for gas engines. B 213. Schweiz Bauzeitung, February 28th and March 7th. Description of a complete gas-power house. B 214. Stahl und Eisen, Vol. XXIII, p. 433-441, 515, and 528. Elaborate discussion of the thermal reactions in the gas-producer and the action of the blast in detail. B 215. Stahl und Eisen, Vol. XXIII, p. 695. Discussion of the changes that take place in the composition of producer-gas between the pro- ducer and the furnace. B 216. Stevens Indicator, January. The blast furnace as a power plant. B 217. Teknisk Tidsckrift, Allmanna Afedlningen, Vol. XXXIII, p. 53. Discussion of the relative merits of various gas-producers for use in iron works. B 218. The Gas Engine, by Hutton, p. 41. Brief discussion of gas-producers, with several illustrations. B 219. Transactions of the Civil and Mechanical Engineers' Society, Volume for 1902-1903, p. 53-68. Discussion of the advantages of the gas-producer as a power generator. B 220. Zeitschr. d. V. D. Ing., p. 157. Gives results of a suction gas-pro- ducer test; abstract of this is given in B 209. 1904. B 221. Cassier's, October. Extensive and detailed discussion of fuel gas for gas engines; several illustrations given. B 222. Cosmopolitan, December, p. 169. Brief discussion of the adapta- bility of gas-producers for marine work. 286 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. B 223. Electric Club Journal, Vol. I, March, p. 65. Lecture on gas-power plants. B 224. Electrical World and Engineer, November 19th. Gives figures taken from a number of plants, indicating marked economies in the use of producer-gas and gas engines instead of steam. B 225. Eng. and Min. Jour., December 8. Section and description of the Wile gas-producer. B 226. Eng. Lond., Vol. XCVII, March 15th, p. 311. Brief description of a German producer-gas plant that uses brown coal briquettes for fuel. B 227. Eng. Land., Vol. XCVII, April 8th, p. 370. Description and illus- tration of a Duff producer-gas plant using soft coal. B 228. Eng. Lond., Vol. XCVIII, August 12th, p. 151. Description and illustration of a Crossley gas-producer plant. B 229. Eng. Lond., Vol. XCVIII, November 4th, p. 450. Description and illustration, with summary of test, of a Pierson suction gas-pro- ducer. B 230. Eng. News, August 4th, p. 96. Description of the producer-gas and gas-engine plant of the Moctezuma Copper Company at Naco- zari, Sonora, Mexico. Abstract of B 281. B 231. Engng., Vol. LXXVIII, August 26th, p. 285. Description of the testing of a Pierson suction gas-producer. B 232. Engng., Vol. LXXVIII, September 2d, p. 295. Description and illustration of a Mond gas plant. B 233. Engng., Vol. LXXVIII, October 21st, p. 540. Description and illus- tration of a gas-producer designed to work on bituminous coal. B 234. Engng., Vol. LXXVIII, November 18th, p. 692. Brief discussion of bituminous coal-gas production. B 235. Engr., February 1st, p. 106, and March 1st, p. 177. Discussion of gas power for central stations. B 236. Engr., June 15th, p. 416. Description and illustration of the Otto producer. B 237. Engr., July 1st, p. 450. Description and illustration of the Bollinckx suction gas-producer. B 238. Engr., October 15th, p. 717. Description and illustration of the Weber suction gas-producer. B 239. Engr., December 15th, p. 821. Illustration and description of pro- ducer-gas power plant. B 240. Eng. Rec., Vol. L, October 1st, p. 406. Brief reference to the economy of an English gas-producer plant. B 241. Eng. Rec., Vol. L, December 3d, p. 654. Description and illustration of a gas-producer plant. B 242. Gasmt., Vol. IV, p. 10 and 27. Discussion of the theory of the com- bustion of carbon in the gas-producer. B 243. Gasmt., Vol. IV, p. 33. Detailed discussion of the manufacture of producer-gas. B 244. Gasmt., Vol. IV, p. 79 and 85. Discussion of the purification of gas; gives several illustrations. B 245. Gasmt., Vol. IV, p. 107. Description and illustration of the Thesian centrifugal gas washer. B 246. Gas Power, October, p 3. Brief discussion of gas-producers. B 247. Gas Power, November, p. 3. Suggestions for a marine-engine pro- ducer. B 248. Gas Power, November, p. 4. Illustrations and descriptions of the Weber, Dunlop, Crossley, Bollinckx, and Nagel producers. B 249. Gas Power, December, p. 16. Discussion of the advantages of gas- engine power plants. B 250. Iron Age, August 18th. Description and illustration of the Thesian centrifugal gas washers. BIBLIOGRAPHY OF GAS-PRODUCERS. 287 B 251. Iron Age, December 29th. Description and illustration of a modern gas-producer plant. B 252. /. C. T. R., Vol. LXVII, p. 1559. Description and illustration of Mond gas plant. B 253. I. C, T. R., Vol. LXVIII, p. 679. Gives comparison of the cost of power with water gas, Mond gas, coal gas and electricity. B 254. Journal of Electricity, December. Illustration and description of a gas-producer power plant equipped with a Pierson producer of special design. B 255. Les Gazogenes, by Jules Deschamps. This book is divided into 15 chapters, contains 432 pages with 240 figures, and gives a com- prehensive discussion of the manufacture and use of producer-gas. B 256. Mar. Eng., October. Description and illustration of a suction gas- producer installed on a ship. B 257. Modern Gas-Engine and Producer-Gas Plants, by R. E. Mathot, chapters 10-13. Extensive discussion of producer-gas engines, producer-gas, pressure gas-producers, suction producers, genera- tors, vaporizers, dust collectors, and the operation of generators. B 258. Oesterreichische Zeitschrift fuer Berg und huettenwesen, September 24th. Discussion and description of the methods used in success- fully gasifying peat, where the gas is to be used in gas engines. B 259. Power, January, p. 1. Discussion of the "blast furnace as a gas- producer"; describes plant and apparatus used in cleaning the gas. B 260. Power, January, p. 50. Brief discussion of the "blast furnace as a gas-producer." B 261. Power, February, p. 72. Description and illustration of the Crossley gas-producer for .bituminous coal. B 262. Power, February, p. 100. Comprehensive and illustrated discussion of gas power for central stations. B 263. Power, April, p. 201. Brief description of a power plant where wood is used in the gas-producers. B 264. Power, June, p. 362. Illustration and description of the Bollinckx suction gas-producer. B 265. Power, July, p. 425. Illustration and brief description of the Thwaite gas-producer for bituminous coal. B 266. Power, August, p. 457. Illustration and brief description of a gas- producer used as a superheater. B 267. Power, September, p. 520. Description and illustrations of several gas-producers; gives summary of costs. B 268. Power, September, p. 560. Brief discussion of gas-producer guaran- tees. B 269. Power, October, p. 632. Description and illustration of the Thesian centrifugal gas washer. B 270. Power, November, p. 696. Brief discussion of the transmission of producer-gas. B 271. Power, December, p. 736. Description and illustrations of suction gas-producers; thorough discussion of details. B 272. Power, December, p. 789. Description and illustration of the Wile gas-producer. B 273. Power, December, p. 752. Summary of comparative economies of steam and gas plants. B 274. Proceedings of the South African Association of Engineers, Vol. I, p. 131. Discussion of the evolution of the modern gas-power plant. B 275. Producer-Gas, by Sexton. Extensive discussion of the physics and chemistry of the gas-producer. B 276. Proc. I. C. E., Vol. CLVIII, p ; 309. Brief discussion of the value of gas-producers. B 277. Proc. I. C. E., Vol. CLVIII, p. 320. Description of methods used in testing gas-producers, giving summary of efficiency, gas analysis, and water consumption. 288 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. B 278. Proc. I. C. E., Vol. CLV, p. 472. Abstract of article on gas-producer plants for heating. B 279. Sci. Am. Sup., September 3d. Illustration and description of a Pierson gas-generating system. B 280. Suction Gas, by O. H. Haenssgen. A monograph devoted to the advantages of the suction gas-producer. B 281. Trans. A. I. M. E., Vol. XXXIV, p. 748. The gas-power plant of the Moctezuma Copper Co. at Nacozari, Sonora, Mexico. Paper containing excellent illustrations and much valuable statistical data of actual working results. B 282. Zeitschr. d. V. D. Ing., October 29th, p. 1656. Discussion of the principles involved in making power-gas, with a summary of the cost of the various forms of fuel gas. B 283. Zeitschr. d. V. D. Ing., November 26th, p. 1793. Extensive discussion of the results obtained with a gas-producer designed for experi- mental work. Gives valuable tables and diagrams. 1905. B 284. American Engineer and Ry. Journal, April, p. 124. Description and illustration of gas-producer power plant. B 285. Bulletin No. 261, U. S. Geological Survey, p. 85. Results of gas- producer tests with different fuels; give's much tabulated data. B 286. Eng. Mag., May, p. 185. Discussion with illustrations of the design and operation of suction gas-producers. B 287. Eng. Mag., May, p. 211. Report of test of a gas-producer plant; abstract of B 285. B 288. Eng. Mag., June, p. 347. Extensive and illustrated discussion of gas-producers for marine work. B 289. Eng. News, Vol. LIII, January 19th, p. 78. Brief description of a Pintsch suction gas-producer. B 290. Eng. News, Vol. LIII, February 16th, p. 161. Illustration and description of Pinstch suction producer. B 291. Engng., March 17th, p. 352. Brief discussion of the cost of gas power. B 292. Engng., March 24th, p. 381. Brief discussion of suction gas plants. B 293. Engr., January 1st, p. 18. Extensive and detailed discussion of gas-producer systems; contains illustrations of the American, Baltimore, Nagel, Weber, Wile, and Taylor producers. B 294. Engr., January 1st, p. 27. Description and illustration of Crossley suction gas-producer. B 295. Engr., January 16th, p. 89. Description, with illustration, of the Fetu De Fize gas-producer. B 296. Engr., February 1st, p. 104. Illustration, with brief description, of a Mond gas-producer plant. B 297. Engr., February 1st, p. 107. Illustration and description of the Campbell suction gas-producer. B 298. Engr., February 15th, p. 137. Description and illustration of the LeTombe gas-producer. B 299. Eng. Rec., Vol. LI, January 21st, p. 89. Same as B 289. B 300. Eng. Rec., May 27th, p. 601. Extensive discussion of the gas-clean- ing methods. B 301. Eng. Land., March 31st, p. 308. Discussion of the theory and opera- tion of suction gas-producers. B 302. Eng. Land., April 14th, p. 360. Description and illustrations of the Baltimore, Benier Benz, Campbell, Crossley, Dawson, and Korting suction gas-producers. B 303. Eng. Lond., April 28th, p. 420. Illustration and description of Acme, Dynamic, Pintsch, Pierson, and Tangye producers. B 304. Gas Engine, January. Brief description with illustration of the Wile producer. BIBLIOGRAPHY OF GAS-PRODUCERS. 289 B 305. Gas Engine, January, p. 3. Brief discussion of the gasification of peat. B 306. Gas Engine, February, p. 39. Brief discussion of gas for power. B 307. Gas Engine, March, p. 70. Brief discussion of the manufacture of gas from vegetable products for power purposes. B 308. Gas Engine, March, p. 94. Discussion of gas-driven locomotives and ships. B 309. Gas Engine, April, p. 110. Description and illustration of the Fair- banks-Morse suction gas-producer. B 310. Gas Engine, May, p. 136. Discussion of power production from gaseous fuel. B 311. Gas Engine, June, p. 165. Description of a coke gas-producer. B 312. Gas Engine, June, p. 175. Discussion of power gas. B 313. Gas Engine, June, p. 178. Discussion of producer-gas units. B 314. Gas Power, January, .p. 3. Illustration and brief description of the Pintsch suction producer. B 315. Gas Power, January, p. 5. Illustration and description of the West- inghouse producer for soft coal. B 316. Gas Power, February, p. 6. Brief description of the Baltimore gas- producer. B 317. Gas-Producers, by W. A. Tookey. British book of 142 pages, devoted to the production of gas and descriptions of representative gas- producers. B 318. Ice and Refrigeration, May, p. 277. Discussion of producer-gas for power purposes. B 319. I. C. T. R., April 14th. Discussion of the principle and requirements of gas-producers. B 320. Iron Age, February, p. 674. Illustrated description of the Swindell gas-producer. B 321. Iron S. M., January, p. 64. Description and illustration of the Amsler gas-producer. B 322. Iron S. M., February, p. 177. Illustrated description of a gas-pro- ducer plant. B 323. Journal American Society Naval Engineers, Vol. XVII, p. 319. Discusses future of marine gas engine and gas-producer. B 324. London Electrician, April 7th. Discussion of the principal forms of gas-producers with special reference to the suction type. B 325. Mining Reporter, March 9th. Discussion and illustration of a Riche gas-producer for the gasification of waste wood, ligneous matter, and agriculture residues. B 326. Power, January, p. 14. Brief discussion of the use of peat as a gas- producer fuel. B 327. Power, March, p. 129. Illustrations and description of the method of manufacture, and use of coke-oven gas in gas engines. B 328. Power, March, p. 178. Brief editorial on the gasification of city waste. B 329. Power, April, p. 212. Description and illustration of a gas-power plant. B 330. Power, May, p. 261. Illustrated description of the Riche gas-pro- ducer. B 331. Power, May, p. 273. Description and illustration of a gas-producer power plant. B 332. Prac. Eng., Vol. XXXI, p. 203. Description and illustration of a suction gas-producer installed on a ship. B 333. Prac. Eng., Vol. XXXI, p. 401. Discussion of gas as a source of power. B 334. Prac. Eng., Vol. XXXI, p. 537. Advantages of producer-gas plants. B 335. Prac. Eng., Vol. XXXI, p. 597, 635, 676, 716, 794. Extensive and illustrated discussion of power-gas plants. B 336. Progressive Age, April 15th. Extensive discussion of producer-gas with special reference to power generation. 290 A TREATISE ON PRODUCER-GAS AND GAS-PRODUCERS. B 337. Sci. Am., February 4th, p. 98. Brief discussion of gas-driven loco- motives and ships. B 338. Sci. Am., February 18th, p. 139. Brief discussion of the gas-pro- ducer, with special reference to power plants. B 339. Sci. Am., March 4th, p. 180. Description and illustration of the Capitaine suction gas-producer for marine work. B 340. Sci. Am. Sup., January 28th. Illustration and brief description of a Pierson producer-gas plant. B 341. Sci. Am. Sup., February 4th. Illustration and discussion of gas- producers for locomotive work. B 342. Sci. Am. Sup., April 1st. Illustrated description of the Pintsch suction gas-producer. B 343. Sci. Am. Sup., April 29th. Illustrated description of the Nagel suction gas-producer. B 344. Sci. Am. Sup., June 3d. Discussion of producer-gas power plants. B 345. Stahl und Eisen, Vol. XXV, March 1st, p. 308. Illustration and brief description of a Swedish gas-producer for gasifying wood and peat in connection with the firing of steam boilers. B 346. Stahl und Eisen, Vol. XXV, April 1st, p. 387. Illustrations and discussion of the use of gas-producers in iron works. B 347. Zeitschr. d. V. D. Ing., February 18th, p. 233. Extensive discussion of the gasification of fuels for the production of power; gives graphi- cal analysis of the thermo-chemical reactions involved. The following references are not related directly to gas-producers, but are quoted in the text : B 348. Fertilizers, by E. B. Voorhees, p. 51. B 349. Treatise on Manures, by A. B. Griffiths, p. 187-8. B 350. Manures and the Principles of Manuring, by C. M. Aikman, p. 355. B 351. Journal of the American Chemical Society, Vol. XXI, p. 1116. Re- port of committee on standard methods of testing fuels. B 352. Trans. A. S. M. E., Vol. XXV, p. 550. Road tests of freight loco- motives. B 353. Trans. A. S. M. E., Vol. XXVI. Road tests of Brooks passenger locomotives. B 354. Ohio State Fire Marshal's report. B 355. Trans. A. S. M. E., Vol. XXVI. Paper on fuel consumption of locomotives. APPENDIX NOTE 1. Temperature is analogous to pressure of gases. The degree of tem- perature is measured by means of temperature scales, of which there are two, viz., the Centigrade and the Fahrenheit. The Centigrade has the freezing point of water at zero, and the boiling point of water at 100; the Fahrenheit has the freezing point of water at 32 and the boiling point of water at 212. Let C. = degrees Centigrade; let F. = degrees Fahrenheit, and F. = f C. + 32; C. = f (F. - 32). Absolute Zero is the point where the volume of the gas, following Charles' law, 12, would become zero. On the Centigrade scale it is 273 degrees below freezing, and on the Fahrenheit scale 491 degrees below freezing. The absolute zero is a convenient point from which to calculate temperatures and for that reason it is of considerable practical value. Absolute temperature is temperature reckoned from absolute zero. Let A. = absolute temperature; let C. = Centigrade temperature; F. = Fahrenheit temperature. A. = C. + 273; A. = f (F. - 32) + 273. A. = F. + 459. NOTE 2. The specific heat of nearly all gases increases with the temperature and for that reason the specific heats corresponding to ordinary tem- peratures are not accurate for high temperatures. The specific heats given in columns "I" and "J" of Table 3 are not accurate enough for dose calculations at high temperatures, and for that reason, in calcu- lating the quantity of heat required to raise gas from standard conditions to any higher temperature, the mean specific heats must be used. The mean specific heats for the gases entering into fuel calculations are given in Table 23, p. 301. Sensible Heat. This is the heat possessed by a body by virtue of its temperature. It is equal to the product of the specific heat per unit of mass and the temperature of the body. If the substance is stated in terms of volume, then, of course, the specific heat must also be stated in terms of volume: for the calculation of the sensible heat of producer- gas. See 63, p. 42. 291 292 APPENDIX NOTE 3. Calorific Power. This term is used to designate the number of heat units that are evolved by the combustion of a unit weight of fuel. The terms " heating power," "heating value/' "thermal value," and "heat of combustion " are frequently applied to the same phenomena. NOTE 4. Latent Heat of Evaporation. The latent heat of evaporation of a body is the amount of heat required to change the body from a liquid state to a vapor, without change of temperature. The latent heat of water on the Fahrenheit scale is equal to 966 B. t. u. per pound, and on the Centigrade scale to 537 calories per kilogram. In both cases the temperature is that of the normal boiling point at atmospheric pressure. NOTE 5. The flow of a gas is, of course, influenced by the pressure. Gas pressures are stated in inches of water, inches of mercury, ounces per square inch, pounds per square inch, and pounds per square foot. The pressure used in the average gas main being low, the ordinary U-tube filled with water is used extensively for measuring the pressure, the value of the pressure being stated as so many inches of water. For the relation of the different units used for expressing gas pressure, see Table 24. NOTE 6. Laws of Chemical Reactions. 1. All atomic and molecular weights are relative. 2. The densities of all gases are proportional to their molecular weights. 3. "The relative number of molecules of a gaseous substance con- cerned in a reaction stands for the relative volume of the gas concerned in the reaction." 4. "The relative volumes of all gases taking part in the reaction are derived simply from the number of molecules of each gas concerned. " 5. If the relative weights in an equation representing a certain reac- tion are called ounces avoirdupois, each molecule of the gas represented by the equation will represent 22.22 cubic feet. If the relative weights are called kilograms, then each molecule of the gas represented by the equation will represent 22.22 cubic meters. 6. "The densities of all gases are found experimentally to be pro- portional to their molecular weights." 7. "The density of any gas referred to hydrogen is expressed numer- APPENDIX 293 ically by one-half its molecular weight." This property may be seen by referring to columns "D" and "E" of Table 3. NOTE 7. Weights and Volumes in Chemical Reactions. By means of the appli- cation of the laws given in Note 6, it is an easy matter to determine the exact weights or the exact volumes of the different substances rep- resented by a chemical equation. An ordinary case which takes place in the gas-producer may be illustrated by the equation for the production of water gas. I I I Molecules C + H 2 O - CO + H 2 Relative weights 12 + 18 = 28 + 2 By this equation, 12 ounces or kilograms of carbon and 18 of water produce 28 of carbon monoxide and 2 of hydrogen. A cubic meter of hydrogen at standard conditions weighs approximately .09 kilograms, hence two kilograms will have a volume of 2 -5- .09 = 22.22 cubic meters. Richards* has already noted that the relation between the ounce avoir- dupois and the kilogram is the same as between the cubic foot and cubic meter, hence the same value that is used to represent cubic meters may be used to represent cubic feet, when the weights are taken in ounces in place of kilograms. In other words, from the preceding, twelve kilo- grams of carbon uniting with 22.22 cubic meters of water vapor produce 22. 22 cubic meters of carbon monoxide and 22. 22 cubic meters of hydrogen, or 12 ounces of carbon uniting with 22.22 cubic feet of water vapor produce 22.22 cubic feet of carbon monoxide and 22.22 cubic feet of hydrogen. This same line of reasoning may be applied to any chemical equation with the same results. NOTE 8. Calorific Intensity. The calorific intensity of a fuel is the theoretical maximum temperature that may be obtained by burning the fuel under any given conditions. It is not proportional to the calorific power, and it will vary with the conditions under which combustion takes place. The combustion of a fuel necessitates the raising of all the combustion products to a certain temperature. The quantity of heat in the products of combustion from a unit of fuel is the same as the calorific power of the fuel. Since the product of the temperature and mean specific heat of the combustion products gives the quantity of heat in the combustion products, we have the following equality: * Metallurgical Calculations, by Dr. J. W. Richards. 294 APPENDIX Let C = calorific power. A and B = constants. Af = mean specific heat of combustion products. t = temperature, or calorific intensity. Q = quantity of heat in combustion products. Mt =C. By reference to Table 23 we see that t is already a function of the mean specific heat and that the general expression for M will be A + Bt = M. For instance, the Af of a cubic meter of H would be .303 + .000027^; the .303 corresponding to A and the .000027 to B. Also Q = Mt = At + Bt 2 but Q = C hence At + Bt 2 = C, and Bt 2 + At - C = The only unknown will be t and this may be solved as an affected quad- ratic equation. 4 /4A 2 X BC-A = V " 2B Flame temperature is discussed in Note 9. NOTE 9. Flame Temperature. If either the fuel or air for combustion is pre- heated, the sensible heat produced by such pre-heating is added to the heat of combustion. In other words, if 1000 heat units are brought into the combustion chamber as sensible heat, the effect in the com- bustion chamber will be the same as if the calorific power of the fuel was 1000 heat units higher. If the fuel is burned with an air excess the amount of heat available from the combustion will be reduced by an amount equal to that re- quired to heat up the excess of air to the temperature of the combustion products. The calculation of the flame temperature available with any fuel gas and under any given conditions, first necessitates the determination of the weights or volumes of the combustion products; the method of doing this is given in 61. The quantity of heat represented by each combustion constituent will be obtained by the use of Table 23, p. 301, and the formula At + Bt 2 = quantity of heat. By the results deduced in Note 8, the sum of the aggregate heat quan- APPENDIX 295 titles represented by the respective combustion products will be equal to the calorific power of the fuel. Since t and t 2 are common factors of all the heat quantities, the aggregate sum will be represented by the product of a new coefficient, As, (corresponding to A) and t plus the product of a new coefficient, Bs (corresponding to B) and t. Let C = calorific power of fuel. Cp = heat carried in by pre-heated air or gas. For perfect combustion with cold air or gas: Ast + Bst 2 = C. For perfect combustion with gas or air pre-heated: Ast = C + Cp. If the gas is burned with an air excess, then the quantity of such excess must be reckoned in with the combustion products, as explained in a 61, and will change the values of the coefficients As and Bs. In any of the above conditions the only unknown will be t, which may readily be solved as explained in Note 8. NOTE 10. Gross and Net Heating Values. In calculating the heating values given in columns "Q" and "R" of Table 3, the results are based on utilizing the latent heat of evaporation (Note 4, p. 292) when the water formed by the combustion of the hydrogen is condensed. In many cases, notably gas engines, the steam is not condensed and hence the heat generated by the combustion is not all utilized. The combustion of one pound of hydrogen produces nine pounds of steam, which, if not condensed, will carry away at atmospheric pressure the latent heat of steam corresponding to these nine pounds. This will be equal to 9 X 966 = 8694 B. t, u. ; hence the heat of combustion per pound of hydrogen, where the products of combustion leave the combustion chamber at a temperature high enough not to condense the water vapor, is 62,100 - 8694 = 53,406 B. t. u. per pound. The 62,100 is known as the gross heating value, and the 53,406 is known as the net heating value. The terms "high" and "low" are also used synonymously for gross and net heating values, and the term "effective" is used synony- mously for low heating values. The use of the term "effective," how- ever, is restricted almost entirely to gas-engine practice. Practically all gas-engine builders state the thermal efficiency of their engines in terms of effective B. t. u. ; in other words, the gas-engine builder does not figure on using the heat locked up in the latent heat of evaporation of the water moisture which is formed by the combustion of the hydrogen in the gas-engine cylinder. From a thermal point of view this is not 296 APPENDIX correct, and the gas-engine efficiency should always be expressed in terms of the gross heating value of the gas delivered to the engine cylinders. The fact that the engine is incapable of utilizing all of the heat evolved by the combustion of the gas should be considered as a defect of the gas-engine system, and the engine should be charged with it accordingly. The question of high and low heating values comes in not only in con- nection with the combustion of hydrogen, but also with all compounds containing hydrogen. The effective heating value per cubic foot of hydrogen is 298 B. t. u.; of Marsh gas is 964 B. t. u.; and of defiant gas is 1573 B. t. u. NOTE 11. In certain cases, the production of a gas excessively high in hydrogen may make the gas very undesirable for certain classes of work; for in- stance, if a gas unusually high in hydrogen is used in a gas engine, more or less trouble may be experienced from back-firing or pre-ignition due to the low compression point of the hydrogen. Further, the gas engine not being able to utilize the latent heat of the condensation of the water vapor which is th3 result of the combustion of hydrogen, the thermal efficiency of a gas engine using a producer-gas high in hydrogen will be lower than when the producer gas is lower in hydrogen. In case pro- ducer-gas is used for burning certain classes of ceramic products, a high percentage of hydrogen, while making the gas process efficient in keeping the temperature of the producer low, may make more or less trouble in th3 combustion chamber on account of the action of the water vapor on the particular ceramic product under treatment. This is especially true in the preliminary stages of the burning of high-grade face brick. NOTE 12. Certain coals containing iron pyrites will, when stored in a damp condition, have a tendency to induce favorable conditions for sponta- neous combustion. For this reason all coals of such a nature should either be stored in such a manner as to secure a thorough circulation of air, or be practically dry before being heaped up in large piles. The percentage of volatile matter permissible in the fuel will, of course, depend on the type of producer used in gasifying and the use of the resulting gas. If the gas is to be used in gas engines, a fuel that is low in volatile matter must be used or else the fuel must be gasified in a producer-gas plant that will secure the removal of the tar before the gas reaches the engine. The fuels that are ordinarily available at the present time for use in gas-producers are as follows: APPENDIX 297 1. Anthracite Coal. 5. Black Lignite. 2. Semi-Anthracite Coal. 6. Brown Lignite. 3. Bituminous Coal. 7. Peat. 4. Semi-Bituminous Coal. 8. Wood. There is no sharp line of demarcation between the first four fuels given in this classification, and it is sometimes hard to tell where one grade stops and another begins. The anthracite and semi-anthracite are used quite extensively in gas-producers where the resulting gas is used in gas engines. Their desirability for this work is due to the fact that their yield of tar is unusually low, and for this reason it is an easy matter to make a clean gas from an anthracite coal. The other fuels are frequently used for making gas for gas engines, but their most general use is in making producer-gas for heating purposes. The following classification gives the constituents of fuels as well as their nature and action: NAME. NATURE. ACTION. Fixed Carbon. Combustible. Supports combustion. Volatile Matter. Partly Combustible. May be made to support combustion. Moisture. Impurity. Increases heat losses. Ash. Red. Impurity. Forms hard clinkers. White. Impurity. Makes fine dust. Sulphur. Impurity. Corrosive. The volatile matter is that portion of the coal which is given off in the form of a vapor when the coal is heated. The volatile matter con- sists essentially of hydrogen and oxygen. The large amount of tar evolved by the gasification of bituminous coal comes primarily from the volatile matter. The problem of the removal of the tar is of such vital importance that it is discussed in detail in Chapter 23. A pound of tar contains approximately 18,000 B. t. u. Many bituminous coals, when gasified in the ordinary producer (where no provision is rrade for the destruction of the tar in the producer), will produce as high as 300 or 400 Ib. of tar per ton of coal gasified. It is evident that the heat loss in such a plant will be excessively high, and also that the producer pro- ducing such a heat loss is not adapted for gasifying fuel of that nature. The following table shows the principal effects of tar in producer- gas for the different classes of work, and emphasizes the importance of having the right kind of a producer for gasifying coals yielding large amounts of tar : 298 APPENDIX Tar -laden producer-gas used in L Gas Engines, will cause (a) Clogging of pipes. (6) Sticking of valve stems. (c) Deterioration of valve seat. (d) Sticking of piston rings. (e) Leakage past piston rings. (/) Increased engine friction. (g) Faulty ignition due to fouling of igniter contacts. 2. Gas-Heating Furnaces, will cause (a) Clogging of pipes. (6) Incomplete combustion, producing smoke. 3. Ceramic Kilns, w r ill cause (a) Stopping up of ports. (6) Incomplete combustion, producing smoke. (c) Discoloration of ceramic product in certain cases. (d) Trouble in water-smoking process. The use of a coal containing a large percentage of moisture will result in producing adverse gasifying conditions in the producer. The amount of heat lost in a gas-producer using a fuel containing a certain amount of moisture may be calculated by means of the formula given for "N" in Table 9. If a fuel containing a high percentage of moisture is gasified in the ordinary producer, all the moisture that is given off will pass into the gas as water vapor. However, if such a fuel is gasified in a down- draft producer, then all the water vapor that is evolved from the moisture will pass down into the fuel bed and may be decomposed into hydrogen and carbon monoxide. In the latter case, the heat loss is not nearly as high as in the former case, since the water vapor passing down through the down-draft producer would replace the use of the steam for keeping the fuel bed at the proper temperature. In other words, the down- draft producer will give better results with a fuel high in moisture than the ordinary type of producer, where the gas is given off at the top of the fuel bed. While the presence of moisture in producer-gas generally has a deleterious effect on any use that may be made of a gas, there is, however, one condition where the reverse may be true. Some gas-engine builders prefer to use a wet producer-gas in their gas engines, claiming that by so doing they are able to secure better operating conditions in the engines. The use of. wet producer-gas in a gas engine will, of course, have a tendency to produce an action in the cylinder similar to that which takes place in a steam engine. The high temperature of the ex- APPENDIX 299 ploding gases will instantly convert the moisture into steam and this will then expand with the expanding combustion gases, and in that way it may increase the amount of work done in the engine cylinder. The advantages of a gas engine using wet producer-gas may be summarized as follows: (a) The securing of more expansion from the working fluid in the engine cylinder. (6) More uniform turning torque for engine. (c) Lower temperature of engine cylinder. (d) Decreased noise from engine exhaust. (e) Decreased temperature of exhaust gases. In cases where a dry gas is necessary, the use of a fuel high in mois- ture will always increase the work of the scrubbing apparatus; not only will more water be required, but the scrubbing apparatus must be larger in order to effectively remove the moisture. If the coal contains con- siderable sulphur, the moisture has a doubly bad effect in that the sulphur fumes in the gas will be converted into sulphuric acid, which will corrode all wrought-iron parts in the scrubbing apparatus. This corrosive action may be so marked as to necessitate the use of cast-iron scrubbers and in fact cast-iron parts for all the connections between the producer and the scrubbing apparatus. The term "ash" is applied to the incombustible part of fuel and includes all the mineral matter left on the grates after the complete combustion of fuel. The chemical combustion of the ash has a very vital bearing on its behavior in the gas-producer, and the effect that it may have on the satisfactory or unsatisfactory operation of the producer. Ashes are generally divided into two classes, white and red. The term "white" is hardly correct, since the ash to which this term is usually applied is more of a steel-gray color. White ashes will give less trouble in the gas-producer than red ashes. In general, white ashes will be in the form of soft lumps or fine powder. Red ash will always be in the form of hard lumps or clinkers. This brings us to the question of the difference between ashes and clinkers. The term "clinker" is applied only to the products formed in the fire by the fusing together of the different constituents that go to make up the ashes. The most active substance tending to the formation of clinker is the oxide of iron. When the oxide of iron becomes heated it will frequently combine with the silica, lime, and potash in the ash and form a semi-fluid mass, which readily adheres to the internal parts of the producer and which on cooling becomes so hard as to make its removal extremely difficult. As a con- clusion of the preceding, the following general statement may be made: Coals yielding a white ash will, in general, not produce any clinkers, 300 APPENDIX while coals yielding a red ash will almost universally produce clinkers in a gas-producer ; hence, inasmuch as the formation of clinkers is always undesirable, the coal yielding a red ash will not be desirable for gas- producer purposes. The following gives some of the common constituents of ash with their specific properties. This list is not complete, but comprises all those that have a direct bearing on the behavior of the fuel in the gas- producer. NAME. PROPERTY. Silica. Produces fine sand residue. Alumina. Produces fine dust residue. Oxide of Iron. Produces clinkers. Lime. Flux for other impurities. Potash. Flux for other impurities. The silica and alumina are the two principal constituents as far as quantity is concerned. The quantity of silica will, in general, be in the neighborhood of 54 per cent, and the quantity of alumina in the neigh- borhood of 36 per cent. However, the oxide of iron, although usually present in small quantities, is the most troublesome constituent of all. The lime and potash are in themselves not injurious, but by fluxing with the other impurities they frequently produce very favorable conditions for the formation of clinkers. This is especially true where the fuel is gasified in a producer having a grate. For fuels containing an ash high in oxide of iron, in addition to lime and potash, the producer so designed as to have the fuel rest on its bottom, and protected from the external air by means of a water seal, will give the best results. The principal effect of the sulphur in coal used in a gas-producer will be to produce conditions favorable for the production of sulphuric acid from the condensation of the gas. The sulphur will generally be con- verted either into hydrogen sulphide for sulphur dioxide. When the sulphur dioxide comes in contact with the water vapor, quite frequently sulphurous acid is formed. Sometimes the sulphur is converted into sulphur trioxide and when this comes in contact with the water, sul- phuric acid is formed. Both reactions are very undesirable, since the corrosive effect of the acid on the scrubbing apparatus will be such as to produce an unusually rapid deterioration of same. Several gas- producer plants have recently been installed in America where cast iron is used exclusively for all connections between the gas-producer and the gas engine. The acids have practically no corrosive effect on cast iron, and for this reason the use of cast iron would practically elimi- nate the troubles from the eating out of metal parts. APPENDIX 301 NOTE 13. Conception of the Producer-Gas Process. The honor of the conception of the producer-gas process falls upon Achilles Christian Wilhelm Friedrich von Faber du Faur, Director of the Wurtemberg Governir.ent Iron Works, at Wasseralfingen, Germany. On December 3, 1832, Mr. Faber du Faur made the first introduction of a hot blast into a blast furnace, and from this time he gave a great deal of thought and attention to the production of combustible gases entirely separate from the blast furnace. In 1837 he started to utilize the blast-furnace gas for heating a rever- beratory furnace. On account of sickness, Mr. Faber du Faur was not able to pursue his studies any farther, but communicated his ideas to Abelmen and Bischof, who went ahead and built producers in accordance with the suggestions made by Mr. Faber du Faur. He was not able to build his own producer until 1843, when a small producer was placed beside the blast furnace, and the resulting gases were used for heating furnaces in connection with the manufacture of iron. TABLE 23 MEAN SPECIFIC HEATS UP TO 2000 C. CENTIGRADE UNIT C. U.* 1 cu. ft. H .0189 + 0000017* 1 cu. ft. N .0189 + 0000017* 1 cu. ft. CO .0189 + 0000017* 1 cu. ft. O .0189 + 0000017* 1 cu. ft. CO, .023 ; 000014* B. T. U. .0341 + 0000017* .0341 + 0000017* + 0000017* + 0000017* + 000014* .0341 .0341 .(Ml 1 Ib. H 3.7 + .0003* 1 Ib. N .2405 + .0000214* 1 Ib. CO .2405 + .0000214* 1 Ib. .2104 + .0000187* 1 Ib. CO 2 .19 + .00011* 6.66 + .0003* .4329 + .0000214* .4329 + .0000214* .3837 + .0000187* .34 + .00011* * See 21, p. 25. 302 APPENDIX TABLE 24 COMPARISON OF PRESSURES 1 Ib. per sq. in. = 2.3 ft. water. = 27.71 in. water. = 51.71 mm. of mercury. 2.035 in. of mercury @ 32 F. = 144 Ib. per sq. ft. 1 in. of water = 5.2 Ib. per sq. ft. .0361 Ib. per sq. in. 1 atmosphere = 14.6969 Ib. per sq. in. = 33.9 ft. of water. = 2116.35 Ib. per sq.ft. INDEX. Absolute humidity, 23 Absorbers, 172. Action in producer, 58. Action of steam, 67. Advantages of gas-firing, 63. Affinity, chemical, 30. Agitation of fuel bed, 98. Air, 48. Air, Pre-heating, 62. Air, Proportion of steam and, 69. Air required for combustion, 40. American Crossley suction producer, 152. American Furnace and Machine Co. producer, 118. Ammonia, Recovery of, 195. Ammonia scrubbers, 195. Ammonia sulphate, 179. Amsler producer, 118. Analysis, coal and ash, 84. Apparatus, Calibration of, 245. Argand steam blower, 75,. Arrangement of heat balance, 90. Artificial respiration, 265. Ashes, Removal of, 98. Ash zone, 58. Automatic feed, Bildt, 137. Automatic feed, George, 139. Atomic weights, 32. Atoms, 30. Backus suction producer, 151. Baltimore suction producer, 164. Beaufume producer, 111. Bench gas, 49. Benzol recovery, 195. Bibliography, 277. Bildt automatic feed, 137. Bischof producer, 103. Blast, Direction of, 56. Blast, Introduction of, 98. Blowers, Steam, 72. Boyle's law, 23. British thermal heat unit, 25. Brown coal, 96. By-product coke-oven producers," 185. By-product coke-oven producers, Status and future, 185. By-product, Definition of, 177. By-product producers, 177. By-products, Method t>f recovering, 180. By-products, Number and value of, 177. Calculation of heat balance, 91. Calculation of moisture in air, 44. Calibration of apparatus, 245. Calorific power of a mixed gas, 34. Calorific power, Relation to effi- ciency, 83. Calory, 25. Capacity, Thermal, 24. Capitaine producer, 227. Carbon dioxide, 46. Carbon dioxide, Deleterious effect of, 79. Carbon dioxide, Effect of feeding on, 80. Carbon dioxide, Effect of leakage on, 81. Carbon dioxide, Effect of tempera- ture and fuel bed, 80. Carbon dioxide in producer-gas, 79. Carbonic anhydride, 46. Carbonic acid, 46. Carbonic oxide, 46. Carbon monoxide, 46. Carbon monoxide poisoning, Symp- toms of, 264. Carbon monoxide, Poisonous action of, 263. Carbon-ratio, 35. Carbureted water gas, 49. Centigrade unit, 25. Centrifugal scrubber, 175. Ceramic kilns, Producer-gas for fir- ing, 197. Charles' law, 23. Chemical affinity, 30. Chronological record, 100. Classification of gas-producers, 55. Cleaning gas, Classification of meth- ods of, 169. Cleaning gas, Object of, 169. Cleanliness, 98. Cleaning plant, 240. 303 304 INDEX. Coal, 95. Coal and ash analysis, 84. Coal gas, 49. Coke quencher, 191. Cold gas efficiency, 87. Combination of laws of Boyle and Charles, 23. Combustion, 31. Combustion, Air required for, 40. Combustion, Heat carried away by products of, 42. Combustion, Temperature of, 31. Combustion, Theoretical, 36. Combustion, Weight and volume of products of, 41. Combustion zone, 60. Commercial gas, 45. Commercial gas constituents, Tabu- lated data of, 50. Commercial gases, Comparison of, 49. Comparison of commercial gases, 49. Composition of gas, Effect of different amounts of steam on, 70. Composition of gas, Effect of steam on, 69. Composition of gases by weight, 39. Compounds, 30. Condition of fire, 61. Condition, Standard, 25. Continuity of operation, 56. Conservatism in improvement, 103. Coolers, 172. Cost of installation, 231. Critical point, 21. Critical temperature, 21- Critical pressure, 21. Currents, Opposite, 26. Currents, Parallel, 26. Dalton's law, 24. Decomposition, Heat of, 32. Decomposition zone, 60. Definite proportion, Law of, 31. Deflectors, 170. Density of gas, 25. Destructive distillation, 33. Direct-firing, 33. Direction of blast, 56. Dissociation, 31. Dissociation temperature, 31. Distillation, Destructive, 33. Distillation, Fractional, 33. Distillation zone, 60. Division of matter, 30. Dowson producer, Introduction of, 102. Draft, Nature of, 56. Duff producer, 125. Duff-Whitfield producer, 224. Early use of gas-producers, 102. Ebelmen's producers, 105. Economy of water, 236. Efficiency, Cold-gas, 87. Efficiency, Conditions governing, 84. Efficiency, Definition of, 82. Efficiency, Effect of steam on, 88. Efficiency, Grate, 85. Efficiency, Hot-gas, 87. Efficiency, Method of finding, 83. Efficiency of gas-producers, 82. Efficiency of steam blowers, 77. Efficiency, Relation to utility, 83. Efficiency, Relation to calorific power, 83. Efficiency, Thermal, 233. Efficiency, Two kinds, 82. Ekman producer, 110. Elements, 30. Equation of pipes, 28. Endothermic reaction, 30. Erecting producers, 238. Ethene, 46. Ethylene, 46. Exothermic reaction, 31. Explosion, Danger of, 237. Explosive mixtures, 43. Eynon-Evans steam blower, 76. Fairbanks-Morse suction producer, 159. Feeding, Effect of on carbon dioxide, 80. Figure of merit, 85. Figure of merit, Limited use of, 86. Filters, 172. Fire, Condition of, 61. Fire damp, 46. Firing, Direct, 33. Firing, Gas, 33. First aid to sufferer, 265. Flame, 32. Flame, Temperature of, 42. Flow of gases, 28. Forms of matter, 21. Forter producer, 121. Fractional distillation, 33. Fraser-Talbot producer, 132. Fuel bed, Agitation of, 98. Fuel bed, Depth of, 98. Fuel bed, Effect of on carbon dioxide, 80. Fuel, Character of, 94. Fuel, Condition of, 94. Fuel constituents, Effect of solid, 200. Fuel Gas Co. producer, 116. Fuel, General data on, 276. Fuel, Heat of combustion, 85. INDEX. 305 Fuel, Means of agitating, 56. Fuel, Size of, 95. Fuel supply, 53. Fuels, Early, 94. Fuel, Use of cheap, 232. Function of steam, 68. Gas, Bench, 49. Gas, Calculation of volume, 36. Gas cleaning, 169. Gas, Coal, 49. Gas, Commercial, 45. Gas, Composition of by weight, 39. Gas, Density of, 25. Gas discharges, Table of, 270. Gas, Distinction between vapor and, 21. Gases, Flow of, 28. Gases, Joule's law of, 24. Gases, Specific heat of, 24. Gases, Table of solubility of, 275. Gas-firing, 33. Gas-firing, Advantages of, 63. Gasification, Rate of, 233. Gas, Illuminating, 49. Gas, Natural, 48. Gas, Oil, 48. Gas, Perfect, 21. Gas, Place of removing, 56. Gas poisoning, Danger of, 263. Gas poisoning, Post-mortem effects, 266. Gas-producer, Adaptability of, 97. Gas-producer, Automatic feeding for, 97. Gas-producer, Composition of gas from, 97. Gas-producer, Construction of, 97. Gas-producer, Continuity of opera- tion of, 97. Gas-producer, Future of, 255. Gas-producer, Heat balance of, 89. Gas-producer, Heat losses of, 89. Gas-producer power plants, 228. Gas-producer power plants, Status of, 228. Gas-producer requirements, 97. Gas-producers, Early use of, 102. Gas-producers, Efficiency of, 82. Gas-producers for ceramic work, Types of, 203. Gas-producers for gasifying wood, 214. Gas-producers, History of, 100. Gas-producers, Operation of, 238. Gas, Scrubbing of, 232. Gas, Specific gravity of a mixed, 39. Gas, Steam-enriched, 58. Gas, Temperature of, 61. Gas, Water, 49. Gas, Weight of a mixed, 38. Gay-Lussac, Law of, 24. George automatic feed, 139. Gram-Calory, 25. Grate efficiency, 85. Grate efficiency, 99. Gravity, Specific, of gas, 25. Heat balance, Arrangement of, 90. Heat balance, Calculation of, 91. Heat carried away by products of combustion ,' 42 . Heat energy, Conservation of, 99. Heat energy, Storage of, 236. Heat of decomposition, 32. Heat insulation, 99. Heat loss, 82. Heat losses, 89. Heat losses, 199. Heat, Sensible heat loss of, 42. Heat, Specific, 24. Heat unit, 25. History of gas-producers, 100. Hot gas efficiency, 87. Humidity, 23. Humidity, Absolute, 23. Humidity, Relative, 23. Humidity table, 268. Hydrocarbons, 47. Hydrocarbons, Value of, 60. Hydrogen, 45. Illuminants, 48. Illuminating gas, 49. Inadaptability of gas engines, 229. Inadaptability of producers, 54. Joule's law of gases, 24. Kitson producer, 116. Labor required, 230. Langdon producer, 113. Law, Dalton's, 24. Law, Joule's, of gases, 24. Law of Boyle, 23. Law of Boyle and Charles combined, 23. Law of Charles, 23. Law of definite proportion, 31. Law of Gay-Lussac, 24. Law of Mariotte, 23. Law of multiple proportion, 31. Laws, Importance of, 21. Laws of thermal chemistry, 30. Leakage, Effect of on carbon dioxide, 81. Lignite, 95. 306 INDEX. Liquid scrubbers, 172. Loomis producer, 139. Lundin flat-grate producer, 214. Lundin stepped-grate producer, 215. Manufacture of producer-gas, 57. Mariotte's law, 23. Marsh gas, 46. Matter, Division of, 30. Matter, Forms of, 21. Means of agitating fuel, 56. Mechanical effect of steam, 71. Mechanical mixtures, 30. Melting points, Table of, 275. Merit, Figure of, 85. Methane, 46. Method of finding efficiency, 83. Method of supporting fuel, 55. Mixtures, Explosive, 43. Moisture in air, 44. Molecular weights, 32. Molecules, 30. Mond by-product producer, 180. Mond by-product producer, Intro- duction of, 102. Mond process, Distinctive features of, 183. Morgan producer, 137. Multiple proportion, Law of, 31. Nagel suction producer, 148. Nascent state, 31. Nature of draft, 56. Nature of producer-gas, 57. Natural gas, 48. Nitrogen, 47. Object of use of steam, 67. Oil gas, 48. Olefiant gas, 46. Operation, Continuity of, 56. Operation of producers, 238. Opposite currents, 21. Otto-Hoffman oven, 185. Otto suction producer, 149. Oxidation, 31. Oxygen, 47. Parallel currents, 26. Peat, 95. Perfect gas, 21. Pintsch suction producer, 150. Pipe coverings, Table of efficiencies, 270. Pipes, Equation of, 28. Place of removing gas, 56. Poetter producer, 225. Poking, 235. Point, Critical, 21. Poisoning, Gas, 263. Pre-heating air, 62. Pressure, Critical, 21. Pressure, Vapor, 22. Producer, Action in, 58. Producer, Examination of for test 245. Producer-gas, Carbon dioxide in, 79. Producer-gas for firing ceramic kilns, Advantages of, 201. Producer-gas for firing ceramic kilns, Difficulties in using, 198. Producer-gas for firing ceramic kilns, Objections to, 198. Producer-gas for firing ceramic kilns. Status of, 197. Producer-gas for firing ceramic kilns, Value of, 198. Producer-gas for firing steam boilers, 210. Producer-gas for firing steam boilers, Advantages of, 211. Producer-gas for firing steam boilers, Fiel'd for use of, 210. Producer-gas for firing steam boilers, Principle of use of, 210. Producer-gas for firing steam boilers, Requirements of, 211. Producer-gas, Ignorance of, 52. Producer-gas locomotives, 255. Producer-gas, Manufacture of, 57. Producer-gas marine plants, 257. Producer-gas, Nature of, 57. Producer-gas portable engines, 259. Producer-gas, Progress made in, 52. Producer-gas, Simple, 57. Producer-gas, Status of, 52. Producer-gas, Uses of, 63. Producer plant, Location of, 237. Producers, Classification of, 55. Producers, Inadaptability of, 54. Producers, Method of operation, 55. Producer troubles, 241. Progress made in producer-gas, 52. Quantity of steam, 70. Radiation, 27. Radiation coefficients, 27. Radiation coefficients, Table of, 268. Radiation loss in pipes, Table of, 269. Radiation loss through walls, Table of, 269. Radiation ratio, Table of, 268. Recuperation, 65. Recuperation, Comparison with re- generation, 66. Recuperation, Value of, 66. Reduction, 31. INDEX. 307 Refuse, 96. Regeneration, Comparison with re- cuperation, 66. Regeneration, Value of, 66. Regenerators, 64. Relative humidity, 23. Removal of ashes, 98. Repair, Cost of, 231. Requirements of gas-producers, 97. Respiration, Artificial, 265. Riche distillation producer, 215. Riche double-combustion producer, 220. Rotating scrubbers, 174. Running producer, 240. Saturation, 22. Saturation table, 267. Sensible heat loss, 42. Siemens producer, 111. Siemens steam blower, 74. Simple producer-gas, 57. Smith suction producer, 161. Smoke nuisance, 230. Smythe producer, 125. Solid jet steam blower, 76. Specific gravity of a mixed gas, 39. Specific gravity of gas, 25. Specific heat, 24. Specific heat of a mixed gas, 34. Specific heat of gases, 24. Specific heat, Variation of, 275. Specific volume of gas, 25. Standard condition, 25. Starting, Ease in, 99. Starting Engine, 239. Starting producers, 238. Steam, Action of, 67. Steam and air regulation, 99. Steam blower, Argand, 75. Steam blower, Eynon-Evans, 76. Steam blower, Siemens, 74. Steam blower, Solid jet, 76. Steam blower, Thwaite, 75. Steam blowers, Efficiency of, 77. Steam blowers, 72. Steam blowers, Types of, 74. Steam boilers, Method of firing with producer-gas, 212. Steam boilers, Results obtained by firing with producer-gas, 211. Steam, Effect of on composition of gas, 69. Steam, Effect of on efficiency 88. Steam, Effect of temperature on action, 68. Steam-enriched gas, 58. Steam, Function of, 68. Steam, Mechanical effect, 71. Steam, Object of use, 67. Steam, Quantity of, 70. Steam, Proportion of air and, 69. Steam regulation for suction pro- ducers, 147. Steam, Summary of principles in- volved in use, 71. Steam, Use of in gas-producers, 67. Suction producers, Introduction of, 102. Suction producers, American, 146. Suction producers, American types, 147. Suction producers, Classification of, 146. Suction producers, Definition of, 146. Suction producers, History of, 146. Suction producers, Operation of, 147. Suction producers, Steam regulation for, 147. Sufferer, First aid to, 265. Supporting fuel, Method of, 55, Summary of principles involved in use of steam, 71. Swindell producer, 119. Tabulated data of commercial gas constituents, 50. Tar collector, 171. Tar, Determination of, 249. Tar, Methods of elimination, 223. Tar, Influence of temperature on, 223. Tar, Nature of, 222. Tar, Object of removal of, 222. Tar, Removal of from gas, 222. Tar scrubbers, 193. Taylor fluxing producer, 113. Taylor producer, 126. Temperature, 24. Temperature, critical, 21. Temperature, Effect of on carbon dioxide, 80. Temperature, Effect of on operation of producer, 85. Temperature of combustion, 31. Temperature of dissociation, 31. Temperature of flame, 42. Temperature of gas, 61. Tension, Vapor, 22. Test, Duration of, 246. Testing producer, 243. Test, Object of, 243. Test, Report of, 251. Test, Value of, 243. Theoretical combustion, 36. Thermal capacity, 24. Thermal chemistry, Laws of, 30. Thwaite steam blower, 75. 308 INDEX. Tower scrubbers, proportions of, 176. Troubles, Producer, 241. Types of steam blowers, 74. Unit, British thermal heat, 25. Unit, Centigrade, 25. United-Otto oven, 188. Unit, Heat, 25. Use of steam in gas-producers, 67. Uses of producer-gas, 63. Utility, Relation of, to efficiency, 83. Vapor, Distinction between gas and, 21. Vapor pressure, 22. Vapor tension, 22. Vapor, Water, 47. Vapor, Water, 71. Value of recuperation, 66. Value of regeneration, 66. Volume of gas, Calculation of, 36. Volume, Specific, of gas, 25. Want of appreciation, 103. Water gas, 49. Water gas, Carbureted, 49. Water vapor, 47. Water vapor, 71. Water vapor, Determination of, 249, Weber suction producer, 150. Wedding producer, 111. Weight and volume of products of combustion, 41. Weight of a mixed gas, 38. Weights, Atomic, 32. Weights, Molecular, 32. Wellman producer, 132. Wile automatic producer, 143. Wile suction producer, 152. Wile water-seal producer, 145. Wilson producer, 226. Windhausen scrubber, 174. Wood double-bosh producer, 130. Wood flat-grate producer, 132. Wood single-bosh water-seal pro- ducer, 132. Wood suction producer, 148. Wood water-seal producer, 131. Wyer suction producer, 165. Zone, Ash, 58. Zone, Combustion, 60. Zone, Decomposition, 60. Zone, Distillation, 60. RETURN 1 2 3 4 5 6 ALL BOOKS MAY BE RECALLED AFTER 7 DAYS DUE AS STAMPED BELOW SEW i UW JI^L MAR 2 i> 1S99 U. C. BERKELEY FORM NO. DD 19 UNIVERSITY OF CALIFORNIA, BERKELEY BERKELEY, CA 94720 re 34109 ?. 37627 a; <, / ft tyt^r 4 UNIVERSITY OF CALIFORNIA LIBRARY