GB478516A - Improvements in or relating to hydraulic cleaning and separating apparatus for the treatment of coal and like materials - Google Patents

Abstract

478,516. Washing granular materials. WINDSOR, G. P. July 21, 1936, No. 20220. [Class 82 (ii)] A jig in which the water pulsations are produced by air or gas under pressure has the air or gas chamber or chambers located below the screen, the flow of air &c. to and from the chambers being controlled by a valve located above the water level. Part at least of the feed water for the jig enters in the form of jets directed downwardly towards a sludge or refuse outlet to assist in discharging the sludge. In the form shown, the washer box 11 is divided into two compartments 12, 13 in which are screens 19, 20 respectively. The division is formed by upstanding walls 14, 15 which are joined at the top at 18 to support the screens, the part 18 extending above the screens and co-operating with a weir 47. The walls 14, 15 merge into sloping bottoms 16, 17 leading to sludge and refuse discharges with rotary valves 23, 24. Air chambers are formed below the screens in the compartments 12 and 13 by hollow partitions 29 ... 35, air being admitted by perforated or slotted pipes 36 ... 42 which extend across the chambers and are connected to control valves above the water level, preferably of the type described in Specification 476,379, [Group XXIX]. The material is fed on to the screen 19 by a shoot 43, the lighter constituent passes out by a shoot 44 and the heavy constituents are discharged under gates 45, 46 at the feed and outlet ends of the washer respectively. The feed trough 43 and the outlet trough 44 overhang the screen to a certain extent, the hollow partitions 30 and 34 are positioned substantially below the ends of the troughs, and the partitions 29 and 35 are so shaped and positioned with respect to the adjacent partitions that a strong pulsating effect is produced through the portions of the screens below the troughs to assist the discharge of the shale. The supply of air to the partitions 29 and 35 is preferably controlled independently from that to the other partitions and may be regulated by a float on the refuse bed. The sludge and refuse discharged by the valves 23 and 24 is preferably carried up pipes 25 and 26 by water injected through inlets 49 and 50 to a dewatering screen 28, the water returning to the jig via the feed trough 43. Feed water is supplied to the jig through downwardly directed jets 48 which assist the flow of the sludge &c. to and through the valves 23 and 24. Specification 478,628 also is referred to.