GB514874A - An improved method of and apparatus for generating a reducing gaseous mixture controlled and continuous at low temperature and for commercial utilisation of the gaseous mixture - Google Patents

Abstract

514,874. Gas-producers ; retorts ; furnace atmospheres. JOHNSTON, G. G. Feb. 10, 1938, Nos. 4177, 20560 and 20561. Void. Convention dates, Feb. 10, 1937, July 12, 1937, and Oct. 29, 1937. [Classes 51 (ii) and 55 (i)] Reducing gases obtained by the action of superheated steam on incandescent fuel in a gas-producer are passed into a reducing chamber adjacent the producer, from which chamber they. are led to exhaust conduits. By this means shale and coal are distilled for oils, cocoanut is dehydrated, or arsenic is removed from arsenical ores. Steam generated in a boiler 13 passes by pipe 20 to a superheating coil 21 in the crown of a gas producer 14, and dry steam is led by distributing pipe 22 and nozzles 27 in the sides of the producer, air entering through annular openings 29 which are normally closed. A reducing furnace 31 is separated from the fuel bed of the producer by a wall 35, and communicates with a longitudinal exhaust passage 36 by ports 37 controlled by dampers 38. The material to be treated is charged on to trucks 91 running on rails 41. Three outflows 43, 44, 45 communicate with passage 36, and have steam scavenging pipes 47, 48, 49. Outflows 43, 45 lead to treatment chambers 69, 72 respectively, and 44 leads to a chimney stack 63 into which residual gases from the treatment chambers pass. By operation of a damper 65, these gases may be diverted to a pipe 64 leading to condensing apparatus, being assisted by a fan 67. A quenching chamber 79, with a steam supply from pipe 83 and the boiler 13, is arranged so that the truck containing the charge is run on rails into the chamber which is closed by gastight doors 80. In practice, when the coke in the producer has been brought to a red heat, openings 15, 16, and 28 are closed, and superheated steam from coil 21 admitted through pipes 24, the temperature of the reducing gases being determined by the depth of the fuel bed, and by the admission of some air. The pressure in the reducing chamber may be raised by partially closing dampers 38 or 58, 59 and 60, and a continuous flow can be maintained for six to eight hours. The quenching chamber is only used for those residues which are combustible when removed from the reducing chamber. For the activation of carbon, the material, such as cocoanut shells; is charged into cylindrical retorts 99 arranged in rows, Fig. 7, steam being admitted through a perforated pipe 113 extending through each retort, and the distillates removed through pipes 103 and a manifold 104. The steam is superheated by passage through pipes 108.