GB391840A - Improvements in or relating to the cleansing of carbonaceous matter - Google Patents

Abstract

391,840. Washing granular materials. BRITISH COAL DISTILLATION, Ltd., (formerly LEICESTERSHIRE (L. & N.) COAL DISTILLATION, Ltd.) and MACHEN, C., 48, Broadway, Westminster. Aug. 7, 1931, No. 22424. [Class 82 (ii).] Carbonaceous material is subjected to low, medium, or high temperature distillation and is then deposited while still hot on the surface of a liquid, e.g. water, moved along the surface for a certain distance, and the floating material then lifted from the liquid preferably by means of an endless conveyer with perforated or gapped blades which dip below the surface of the liquid. To prevent the entry of liquid into the cells of the porous carbonaceous material the surface of the liquid is maintained substantially at boiling point, or the material may be partially cooled by sprays before being deposited on the surface of the liquid. In the preferred form, in which these two methods are combined, residual fuel from the distillation furnace is carried by a conveyer a up a passage c in which it is subjected to a preliminary cooling by sprays q of water or waste effluent and is then passed down a shoot d on to the surface e of water in a tank f. A revolving paddle g breaks up the fuel, the heavier particles sinking and being discharged by a conveyer o and bucket elevator p while the more buoyant particles are carried across the surface and up a sieve n by inclined perforated blades m of a conveyer h which travels parallel to the surface from the sprocket wheel j to a guide wheel k and then upwardly. Bubbles of air or other gas may be liberated below the surface by means of perforated pipes r to enhance the buoyancy of the fuel. The conveyer may have, instead of the blades m, bottomless perforated buckets in which case the sieve n may be dispensed with. The water level in the tank f is kept constant by the supply of additional water to a subsidiary tank s communicating with the tank f by an aperture u so that no disturbance occurs on the surface e, which, by this means, is maintained substantially at boiling point. The passage of the fuel across the surface of the water is so regulated that the fuel is efficiently quenched, but retains sufficient heat to expel excess water when lifted from the surface.