GB492072A - Improvements in or relating to the low temperature carbonisation of fuels - Google Patents

Abstract

492,072. Low temperature carbonization. METALLGES. AKT.-GES. June 10, 1937, No. 16110. Convention date, July 4, 1936. [Class 55 (i)] In the low temperature carbonization of fuel, preferably briquetted, in a vertical retort in which carbonization and cooling zones 2 and 4 are formed by maintaining separate gas circulations therein, the offtakes 9b in the upper part of the cooling zone and the gas-inlets 9a in the lower part of the carbonization zone are staggered relatively to each other and are interconnected through a blower or injector so that by adjustment of the operation of the latter a differential pressure is maintained between the zones to allow a part of the gas entering into the carbonization zone through the gas-inlets 9a to be spread over the whole area of the retort and to be withdrawn with the gas circulating in the cooling zone through the offtakes 9b. The mixture of gases is withdrawn by a pair of blowers 10a, 10b and mixed in a pipe 11 with heating gas from a combustion chamber 8, the resulting hot gases at a temperature of 500-600‹ C. being supplied to the gasinlets of the carbonization zone. The gas is withdrawn from the latter through offtakes 14 by a fan 13 and after circulation through a condensing plant 16 is returned through pipe 17 to the base of the cooling zone. Part of the gas from the carbonization zone is byepassed through pipe 18 to the burners 19, fed with air through pipe 21, of the combustion chamber 8. Excess gas is withdrawn at 20. The offtakes and intakes 9a, 9b, are constructed with roof-shaped hoods. In a modification of the invention, the blowers 10a, 10b are replaced by an injector, the nozzle of which enters a mixing chamber connected both to the offtakes 9b and intakes 9a and is fed with heating gas from a compression chamber communicating with the combustion chamber 8. The injector is operated either by a blower arranged in a byepass between the offtake pipe from the outlets 9b and the compression chamber or by a blower arranged in the byepass which feeds the burners of the combustion chamber with combustible gas. Specification 242,618, [Class 55 (i)], is referred to.