THE COMPLETE GASIFICATION OF COAL
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that the sensible heat of this gas was sufficient to carbouize the layer of coal during the run, thus giving a mixture of water gas and hydrocarboiis. Th.e mixture passed through the regenerators and downwards through the fuel in the second generator,
whereby the hydrocarbons and ammonia were decomposed. The air for the biast, as will be seen from the illustration,
was preheated by passage through therecuperator placed above the stack valve.
There is no question that one of the pioneers of complete gasification on successful lines was H. Strache. whose plant is shown in Fig. 462. It will be seen that the plant consists of a short vertical retort superimposed 011 a water-gas producer. The plant is oper-ated in the ordinary manner with runs andblows, the water gas during the run passing out by way of the retort and sweeping the coal gas with. it to the mixed gas outlet, while
the blow products are caused to flow through nostrils into a chamber encircling the retort where, by the admission of secondary air, the combustibles they contain are burnt and assist in providing heat for the carbonization of the coal. Strache introduced his plant in 1895, and called the gas mixture “ Doppelgas.” On an average the plant yields 57,400 cubic .feet of gas per ton of coal utilized, the calorific power of the gas being 374 B.Th.U. per cubic foot. Strache asserts, but the statement is open to question, that the yield of subsidiary
Fig. 461.—Aakt’s Gas Pi.ant.