Gas generator

G. is usually the mine, vnutr. the walls of which are lined by refractory material. From above this mine it is stoked, and from below will be fanned. The layer of fuel is supported by fire grate. The processes of gas generation in the layer of fuel g. are shown in Fig. 1. Supplied in g. blowing at first penetrates the zone of ashes and slag 0, where it a little podogrevayetsya, and further it enters the incandescent layer of the fuel (it will oxidize, zone, or combustion zone I), where oxygen of blowing enters into reaction with the combustible elements of fuel. The formed products of combustion, rising upward at g. and being encountered with the incandescent fuel (zone of gasification II), are restored to carbon monoxide and hydrogen. With further upward motion of the strongly heated hydrogenation products the therm. decomposition of fuel (zone of the decomposition of fuel III) occurs and hydrogenation products are enriched in decomposition products (by gases, by resin and water vapors). As a result of the decomposition of the fuels are formed at first the semicoke, and then coke, on the surface of which with their lowering downward occurs the restoration of products of combustion (zone II). With the lowering the combustion of coke even occurs below (zone I). In the upper part g. the drying of fuel by the heat of the being risen gases occurs and it is steam.

Depending on that, in which form will be given in g. oxygen of blowing, the composition of generator gases changes. During the supplying in g. of one air of blowing is obtained by air the gas, the heat of the combustion of which depending on the processed fuel kolebletsya from 3,8 to 4,5 MJm³ (900 - 1080 kkal/m³). Using the blowing, enriched by oxygen, obtain Vol. n. steam-oxygen mixture (containing a smaller quantity of nitrogen, than air gas), the heat of the combustion of which can be brought to 5-8,8 MJ/m³ (1200-2100 kkal/m³).

With the work g. in air with the moderate additive to it of water is steam it is obtained the mixed gas, the heat of combustion of which (depending on initial fuel) kolebletsya from 5 to 6,7 MJ/m³ (1200-1600 kkal/m³). And finally during the supplying into the incandescent layer of the fuel g. of water vapor is obtained water gas with the heat of combustion from 10 to 13,4 MJ/m³ (2400-3200 kkal/m³).

Despite the fact that the idea g. was advanced at the end the 30's. 19 v. in Germany (By bishchofom into 1839 and Ebel'manom into 1840), their industr. application began after By f. Siemens (1861) was proposed the regenerative principle of the heating of plant furnaces, which made it possible to effectively use generator gas. By inventors of the first by prom. G. there were brothers f. and V. Siemens. Their construction g. received general propagation and she existed for 40-50 years. Only in the beginning. 20 v. appeared the more advanced constructions.

Depending on the form of the processed solid fuel the types g. are distinguished: for the emaciated fuel - from neznachit. by the output of volatile substances (coke, anthracite, lean coal), for the bituminous fuel - it means, by the output of volatile substances (gas and brown coal), for the wood and peat fuel and for the repulsions of mineral fuel (coke and carbon trifle, remainders it will enrich, productions). Are distinguished g. with the liquid and solid slag disposal. Butuminous fuels usually are gasified in g. with the revolving water pan, and wood and peat - in g. of large vnutr. of volume, since processed fuel- has neznachit. density. Small fuel- is processed in g. of high pressure n in the weighed or fluidized bed. According to the designation g. it is possible to divide into the stationary and the transport, while on the place of the supply of air and gas bleed on g. of the straight, inverted and horizontal process. In g. of straight process (Fig. 2) the motion of the carrier of oxygen and generatrix of gases occurs from bottom to top. In g. with the reversed process (Fig. 3) the carrier of oxygen and resultant gas dvizhutsya from top to bottom. For guaranteeing the inverted flow the middle part of such g. is supplied with the tuyeres, through which is introduced the blowing. Since the suction of the formed gases is achieved from below g., then combustion zone I (oxidizing)is located immediately under the tuyeres, lower than this zone follows reduction zone II, above the combustion zone I is located zone III - pirogenetich. of the decomposition of fuel, proceeding due to the heat of the incandescent burning coke of zone I. The drying of the samogoverkhnego layer of fuel in g. proceeds due to the heat transfer from zone III. In g. with the horizontal process the carrier of oxygen and resultant gas dvizhutsya in the horizontal direction.

With the operation g. soblyudayetsya the pressure schedule and temperature, whose the value depends on the processed fuel, the designation of the process of gasification and construction G.

The explosion of gas industry in THE USSR led to the almost complete replacement of generator gases by natural and following, since the prime cost of the latter is considerably below. In the foreign countries, where it is small natural gas, by g. widely adapt in different branches industries (FRG, Great Britain).

Lit.: Mikheev v. p., gas fuel- and his combustion, l., 1966. N. i. ryabtsev.