GB371962A - Improvements in internally heated vertical retorts used for the distillation of shales, lignites, peats, coals or other earthy oil bearing substances - Google Patents

Abstract

371,962. Distilling solid carbonaceous materials. MONEY, R. J., 5, Victoria Street, London, and PONTET, H. D., 41, Parkhill Road, Croydon. Feb. 5, 1931, Nos. 3611 and 14692. [Class 55 (i).] Relates to a retort for distilling shales, lignite, coal, or other earthy oil-bearing material, by a method in which the material is internally heated and the combustion that produces'the distillation commences at the top of the retort and proceeds downwards towards the lower end, the distilled products being removed from the lower end, as described in Specifications 211,033 and 221,388, [both in Class 55 (i), Coking &c.]. According to the present invention, the retort comprises a grate or base which slopes downwards to one or more outlets for the removal of the treated material, ducts are distributed over the lower part of the retort for the extraction of the distilled gases and vapours, and means are provided for controlling the rate at which the distillate is extracted from positions at different altitudes in order to cause the zone of distillation to conform to the contour of the grate during the later stages of the distillation process. The retort may consist of a chamber 1, Fig. 1, provided with a hopper or other charging means 3 and with inclined grate bars 4 supported on girders 5 carried on a foundation 7. The girders have a floor 6 on their undersides so that a space 22 is formed below the grate into which the distilled gases and vapours may be drawn. Exhaust ducts 8 .. 11, fitted with valves, lead from the space 22 to a manifold which is also controlled by a valve. Air and gases are introduced through pipes 12 to promote combustion of the material, and an outlet 19 having a discharge door 19a is provided for the removal of the treated material. In use, the retort is filled with shale and combustion is started at the top of the charge. The zone of combustion moves steadily downwards and distillation takes place below it, the volatile products being drawn off through the ducts 8 .. 11. When the combustion reaches the top of the grate bars, the valve in the duct 8 is closed so that gases are no longer drawn off from the highest compartment of the space 22. The ducts 9, 10, 11 are then closed in succession as the combustion proceeds so that the zone of combustion is no longer horizontal but bends until it follows the contour of the grate, and the process can be continued until substantially all of the material has been distilled. Finally, the spent charge, which consists of lumps of material in coke form, is removed by raising the door 19a so that the material falls through the opening 19. In a modified construction, 'the grate may be wedge-shaped, the bars meeting in line across the centre of the retort, and in another construction, the bars may slope downwards from a ridge to the sides of the retort. A preferred form of construction comprises a retort with bars 4, Fig. 3, which slope downwards from the sides to an outlet at the centre. Combustion over the conical grate is controlled by exhaust ducts 27 which lead into a manifold 29 and are controlled by valves 28. The outlet at the centre of the grate is fitted with a closure 26 which is mounted on wheels 36 and can be moved horizontally by means of a leading-screw 38. A flexible hose 41 enables gas to be withdrawn from the space 31 beneath the grate bars of the closure. Any liquid oil which is formed will be drawn away through the ducts, or drains may be provided for its removal.