GB589516A - Improvements in process of and apparatus for the heat treatment of hydrocarbons and carbohydrates - Google Patents

Abstract

589,516. Distilling and gasifying carbonaceous materials. BABCOCK & WILCOX CO. March 23, 1945, No. 7375. Convention date, March 23, 1944. [Class 55 (i)] In the distillation of hydrocarbon and carbohydrate materials comprising coal, lignite, peat, sawdust, heavy oil, shale &c. a mass of the material mixed with hot solid heat transfer material is passed downwardly through a retort 10 in which it is first subjected to low temperature distillation, then to a higher temperature distillation followed by a final combustion of the carbon deposited on the heat transfer material which is withdrawn at 260- 520‹C. to supply heat to the low temperature zone, ash being first removed as by a steam blast in section 91 of the discharge pipe. In the apparatus shown a gasification of the material with superheated steam is effected below the high temperature distillation zone. Circumferential outlets 35, 36 leading to pipes 42a and valved discharge lines 43, 45, provide for separate withdrawal of the low temperature distillates and the gases from the lower zone at which a temperature of 927-1,250‹C. is reached. Air for the combustion zone is introduced by a fan through a pipe 30 into which steam is also admitted to cool the heat transfer materal; a supplementary steam inlet for the water gas reaction comprises a vertically adjustable spider 29. Combustible material such as suitably sized coke may be used as heat transfer material, but it preferably comprises pellets of ceramic refractory or corrosion resistant alloy. In starting up, the retort is filled with the pellets and feeding and elevating means for their circulation through the retort started. Fuel gas is admitted through the outlet ports 35, 36 and burnt, the combustion products escaping through a top outlet 81. The coal &c. crushed, e.g., to ¢in. mesh size, is then introduced from an overhead bin through a feeder co-ordinated with the discharge feeder 52 and when operating temperatures are reached the fuel gas supply is discontinued and outlet 81 closed. Some gases may, however, be withdrawn from a top outlet 82 in addition to either of the ports 35, 36.