Patent GB-292495-A (GB)
Title: Improvements in or relating to the separation of intermixed divided materials
IPC: B03B4/02
Filed: 1928-04-12
Abstract: 292,495. Peale, R., Davies, W. S., and Wallace, W. S., (Assignees of Davis, K.). June 20, 1927, [Convention date]. Pneumatic separating.-Relates to a process and apparatus of the kind described in Specifications 287,184 and 290,276 for separating intermixed divided materials, such as coal and stone, by subjecting the mixture on a pervious supporting table to the stratifying action of an upward air pressure simultaneously with a mechanical jigging movement, and consists in providing means whereby the air pressure has a general gradation over the whole extent of the table together with independent control over small areas. As described, the table is of elongated form, Fig. 1, and consists of two sections 1, mounted in a frame, Fig. 6, having side and end members 2, 3, 4. The outer edges of the sections 1 are supported on beams 17 and the inner edges are supported by a central bar 21 adjustable vertically so as to vary the transverse inclination of the sections which together preferably form an upwardly concave surface. Each section has a series of separating partitions 37 extending forwardly and outwardly by which the heavy materials are moved to the side channels 39 and into lateral discharge openings. Preferably the table is subdivided by partitions 38 which extend completely to the sides and prevent movement of the heavy materials longitudinally while permitting the lighter material to ride over them, baffle plates 97 being provided to facilitate this movement. The separating and divisional plates increase in height outwardly either gradually or in steps, and may also increase in height in the forward direction of the table. At the forward end, the table is formed with two inwardly inclined edges 40 to provide a wide area for the discharge of the lighter material, The frame in which the table sections are mounted is pivoted at one end 147 and adjustably secured at the other end by a slotted lug 154 to a second frame 130 mounted on links 138 on the stationary air chamber 142. The intensity of the pneumatic action is graded over the whole extent of the table by providing zones of different perviousness and in addition is controlled by dividing the space under the table into isolated compartments by partitions 7, and providing detachable damper plates 99. Each of the compartments may be further subdivided by fixed vertical partitions or some of the damper plates may carry vertical extensions. The discharge openings 71 for the heavy materials are provided with adjustable slides 65, 72, Fig. 2, for varying their extent both longitudinally and vertically and lead to passages 74, with weighted gates. Backward air pressure to prevent the discharge of lighter material through these passages is provided by connecting them to the source of air pressure, and plates may be provided over the table surface in the neighbourhood of the discharge openings to diminish or prevent the upward air pressure at these points. The frame is reciprocated by springs 171 mounted on guide rods 166 and by an eccentric rod 177 and chain 175. The material is fed to the rear end of the table from a hopper 101, rotary scoop 107 and shoot 113. Adjustable guide plates 117 are provided to control the feed transversely of the table.