GB648744A - Process and apparatus for destructive distillation. - Google Patents

Abstract

648,744. Destructive distillation. DALIN, D., and HEDBACK, T. J. Feb. 8, 1946, No. 4029. Convention date, Feb. 10, 1945. [Class 55(i)] Wood, coal or shale is distilled in a retort to which an excess of heat is supplied by an enclosing combustion-chamber, the temperature of the charge being controlled by passing a heat-absorbing medium through ducts arranged in or adjacent to the retort walls, the ducts being so arranged that a greater degree of heat extraction is effected at a zone which would otherwise become overheated, than at another part of the retort which is not liable to overheating. The heat-absorbing medium may be water or steam and the retort may be of rectangular or circular section. As shown 'in Figs. 1, 2, the retort 2 is rectangular in section and divides the outer chamber into two combustion spaces which are fed by shoots and valves 9, 10, and are provided with rotary discharge means 4. The fuel may be coke discharged from the retort 2 by a worm conveyer 6, and delivered to the shoots 9 by an elevator 8. The retort is fed from a hopper 3, past valves 5 which prevent the escape of gas, and descent of the charge is maintained by rotary means 4a. Ash is removed through the water seal 11, 11a and gas is withdrawn through a pipe 13a. Cooling pipes 12a are arranged adjacent to the retort walls, and extend to different levels so that the cooling-effect is varied as necessary. Cooling pipes 12b are arranged, as described in Specification 641,541, in the fuel bed to maintain the fuel near but below the sintering temperature. Air for combustion is supplied at 21 and combustion products escape at 22. A number of retorts of downwardly divergent tapering section may be arranged side by side in one large combustion chamber, the gas being withdrawn from the top of one retort and from about the middle of another retort. In a modification, the retort is enclosed in a chamber which is fired at the bottom by gas-burners, and the cooling pipe, or pipes, is coiled around the retort, the coils being spaced closely at the bottom of the retort in the vicinity of the burners. According to the Specification as open to inspection under Sect. 91, the wall of the retort may be composed of tubes or of tubes spaced by distance pieces- This subjectmatter does not appear in the Specification as accepted.