Types of Gas Gas producers have been developed after two general types: (1) The Siemens gas producer, which operates without artificial blast and is typical of the older producers; and (2) the Taylor producer on the plan of the blast furnace, equipped with a rotative ash table and operating with a forced steam-blast, and representing the later develop ments in this line.
Fig. 1 shows a vertical section through a Siemens gas producer and regenerator furnace. It consists of two essential parts— the gas pro ducer proper it which the raw fuel is converted into a combustible gas and the furnace with its regenerators or chambers for storing the waste heat of the flame, given up to the incoming air gas. As the air is drawn into the producer lugh the firebars A, a certain quantity of OR water contained in the trough B is vaporized by he heat of the fire above, and mixing with th( air is drawn with it into the fire. The neomsary indraught of air, and the pressure re quited to cause the gas generated in the pro ducer to flow into the furnace, is obtained by means of the vertical uptake C usually built of brick; the horizontal iron tube D, of rela tively large diameter; and the vertical tube E, leading to the gas flue F of the furnace. By this arrangement, asAse.hot gas rises from the pi, and passes through the tubes, it is con,iderably reduced in temperature, thus ren dt, ng its density much greater at the furnace end than at the producer, and thereby causing a -diction and an indraught of air at the latter. This type is practically the one used in all plants making illuminating gas.
2 shows a vertical cross-section of a for producer charged with anthracite coal. Tht incandescent fuel is supported by the bed of ash put upon the rotative ash table A, before firing, and kept there constantly as an essential feature in the successful operation of the pro ducer. The rotative ash table has a greater di ameter than the bosh B, and is placed at such a distance below the latter that upon being re volved, the descending ash forms its own slope at n angle of about 55° and is uni fot .nly b).gravity over the periphery of the ash table into the sealed ash pit C.
When operated regularly, the line between the ash and the fuel is kept always about six inches above the cap D of the central air pipe E, thus allowing the fire to come in contact only with the brick lining, so that all the iron work is protected from the heat. The height of the fir( line is maintained by grinding or revolving th ash table once every 6 or 24 hours, accord in to the rate at which the producer is worked.
The air blast is furnished, usually, by a Lm jet blower, but a fan blower may be used if more convenient, and a pipe from some aux iliary source of steam run into the vertical air pipe to supply the steam required for softening. the clinkers and maintaining the proper tem perature of the producer.
The producer as shown is equipped with a Bildt continuous automatic feed device F, con sisting of a receiving hopper G, which sur mounts the main storage magazine H, the com munication between the two being regulated by a horizontal rotary register J, operated by a lever: The distributor plate K is suspended be low the main magazine, and supported by a steel shaft L, which passes upward through the storage cylinder. Both the hood of the distrib utor plate and the inverted conical base of the magazine are water-cooled, the tendency of the cooling water and the location of the plate above the gaseous current tending to facilitate the discharge when using strongly caking coals. The receiving hopper is rotated by means of a worm wheel and worm-drive attached to the upper end of the shaft, and the distributor plate is rotated by means of the radical arms and huh of the receiving hopper, which arc also keyed to the steel shaft. A hand-wheel nut upon the threaded end of the axis affords means for adjusting the distance between the distributor plate and the coal reservoir, and this adjust ment, together with the variable speed secured by means of the stepped cone pulley M, permits of a ready control of the rate of coal dis charge. Experience shows that the use of feed ers equipped with distributing plates not only tends to reduce the amount of furnace wear, labor and repairs, but also results in a great reduction in the coal consumption.