GB919342A - Improvements in or relating to apparatus for the cleaning or separation of coal or other granular material - Google Patents

Abstract

919,342. Washing granular materials; centrifugal separators. COAL INDUSTRY (PATENTS) Ltd. May 6, 1959 [May 6, 1958], No. 14437/58. Classes 23 and 82 (2). Coal is cleaned by injecting a liquid suspension thereof tangentially to the outer wall of a separating vessel, an inner member of which causes the feed to take a downward spiral path between the outer wall and the inner member, liquid and cleaned solids overflowing above the inlet for the suspension and fine refuse being retained at the bottom of the vessel by a portion having a depth greater than its width and to the lower end of which liquid is admitted at a limited maximum pressure. As shown, feed enters the separating vessel tangentially through inlet 1 in the outer wall 3 and flows between the wall and inner member (not shown). A cone 4 adjoining wall 3 is preferably three times the diameter of the outlet spigot 5 to which it is connected by a pipe 6. A constant level tank 10 with an adjustable level control 11, filter 12 and flow control orifice 9 supplies water to pipe 8 whence it flows upwardly through spigot tube 5 and retards the downward flow of refuse. The maximum pressure at the base of spigot tube 5 is controlled by adjustable weir 18. Water is supplied tangentially to the pipe 6 by a pipe 51. The refuse is discharged from the spigot and delivered by a pump 31 to a cyclone 46, liquid from the cyclone returning to tank 10. Cleaned coal is discharged through the upper chamber 36. In a modification having two arrangements with weirs 18, the arrangement having its weir at a lower level is provided with means for manually or automatically controlling the liquid by-passed by the arrangement. Pipe 6 may comprise one or more inclined portions with or without one or more vertical portions and it may be of uniform or varying cross-section. Specification 769,429 is referred to.