GB307526A - Improvements in or relating to a process and apparatus for the dry separation of masses of materials - Google Patents

Abstract

307,526. Sutton, H. M., Steele, W. L., and Steele, E. G. Nov. 10, 1927. Pneumatic separating. - Relates to apparatus for separating granular material, such as a mixture of coal and heavy impurities, of the kind in which the materials are given a jigging movement on a pervious reciprocating deck which comprises receiving and delivery portions set at an angle to each other and through which upward currents of air are passed. The invention is described as applied to apparatus having the Y- shaped separating deck shown in Fig. 1, and described in Specification 207,094 and comprises (a) inclining the delivery ends B upwardly relatively to the receiving portion A of the deck as shown at 13, Fig. 13; (b) forming the riffles C of L-sectioned perforated strips, the horizontal arms 1 of which are lifted slightly from the surface of the deck as shown in Fig. 10 so as to avoid obstruction of the, deck perforations by particles carried in the air stream; and (c) providing means at the central deck rib 32 for directing a current of air across the path of flow of the materials over the deck. The perforated riffles taper down towards the central unobstructed passage 4 on the deck and are combined with the usual solid riffles to form troughs in which the effect of the air pressure is reduced so as to facilitate the settling of the small particles of heavy material which is conveyed by the troughs to the passage 4. In order further to control the air pressure in the areas occupied by the riffles, perforated metal troughs 6, Fig. 12, with closed rear ends are secured to the under surface of the deck. The means for providing a cross-current of air at the banking bar 32 consists of a box 33, Fig. 15, connected by an expansible pipe 40 with the air chamber under the deck and provided with a horizontal slot 34. The box is mounted by the adjustable fastening 37 to permit control of the direction of the air current. The air controlling baffle-plate 22, Fig. 2, in the air chamber 15 is hinged at its front end 24 and adjustably secured at its rear end 26. The passage of the air through the plate is directed rearwardly by inclined lips 21. Preferably the edges of the plate under the tailings discharge areas of the deck are unperforated and the perforations in the plate increase in size rearwardly and laterally. A second fixed baffle-plate 22<1> with rearwardly inclined lips 21<1> may be provided. The surface of the deck is roughened for the feed of the materials by stamping the necessary configuration in perforated sheet metal. In Fig. 12, the deck is shown as formed of corrugated sheet material 8. A modification consists in stamping projections and recesses in the material.