Engineering Wonders of the World
Volume I

THE DEVELOPMENT OF THE GAS ENGINE. 221 with water. Plates projecting from the sides of the tank compel the gas to come into con- tact with the moving wet surfaces of the discs, which catch the dust and wash it off as they pass through the water below. The mud is appreciated on the Continent and in America. At the Paris Exhibition of 1900 there was shown a huge blowing engine of 750 h.p., operated with blast-furnace gas. It had a cylinder of 4 feet 3| inches bore and 4 feet Fig. 10.-DIAPHRAGM-TYPE SCRUBBER. 7 inches stroke, ran at 80 revolutions per minute, and with an initial explosion pressure of from 310 to 325 lbs. to the square inch pro- duced a piston thrust of 300 tons. It is now at work blowing furnaces at Ettingshall. Still larger engines followed, some con- structed on the Otto four-stroke cycle, and provided with a sufficient number of cylinders drawn off through a cock at the bottom. A third type (Fig. 10) causes the dirty gas to pass repeatedly under the lower ends of dia- phragm plates immersed in water. These illustrations, to which should be added to give a regular turning effort. These engines were very large and heavy for a given power, even though the mean effec- The Nürnberg Engines. Fig. 11.-SCRUBBER FOR ORDINARY GAS PRODUCÉR. tive pressure in their cylinders ran very high. For this reason the Nürnberg Gas Engine Company have adopted the four-stroke double- acting type, which, while giving with one cylinder an impulse every revolution, avoids the use of external pumps. These engines are very useful for driving factories, blowing fur- naces, and turning electric generators of a kind that at once demands and proves steady running. The company has supplied to this country engines of 1,200 and 2,400 h.p. These monsters, shown in Fig. 12, utilize the waste gas of coke ovens at the Powell Duffryn Steam Coal Company, Bargoed, to generate elec- tricity. Some makers have developed Clerk’s idea in very large gas engines having cylinders closed at both ends and furnished pumps. In Fig. 14 we give a diagrammatic section of a Kört- ing engine built by Messrs. Mather and Platt. This shows with separate The Two=stroke Engine. Fig. 11, showing an ordinary gas-producer scrubber, will give the reader a fair idea of how this particular difficulty has been dealt with and overcome Though Thwaite did not make much head- way in England, his experiments were much the air-pumps (ap1 and ap2), the gas pumps (gp1 and gp2), their valves, and their pipe connections with the two ends of the main cylinder, mc. The piston, p, is almost as long as its travel, so that it uncovers at the end of each stroke a ring of exhaust ports in the 1^■■