GB334877A - An improved method and apparatus for separating materials of different physical characters - Google Patents

Abstract

334,877. Chance, H. M. May 7, 1929. Pneiematic separating.-In the separation of granular materials according to density, the mixed materials are subjected on a support. ing surface to agitation which stratifies them and moves them in a predetermined direction and a high velocity current of air or other gas is passed over the surface so as to increase the movement of the upper lighter layers and cause them to discharge at a different point from the lower heavier layers. The surface may be a table, the. floor of a trough &c. and the agitation and traverse of the materials may be caused by inclining the surface and imparting a shaking movement thereto. Alternatively the agitating medium may be a current of air passed upwardly through a pervious supporting surface. Apparatus for carrying out the invention is shown in Fig. 1. The supporting surface is in the form of a trough 1, the floor 2 of which is stepped at 3 and which is supported by flexible hangers 7 and rollers 8 and reciprocated by an eccentric 5 and connecting rod 4. The materials are fed from a hopper 11 and air from a blower 9 connected to the trough by a bellows 10. At the discharge end of the trough, the lighter materials are blown into the bin 14 and the heavier drop into the bin 15. Another construction of apparatus is shown in Fig. 2. A casing 20 encloses two reciprocating elements 28, 29 each consisting of a series of plates 41, 41<1> with gaps 42, 42<1> and a lower tray 43 with a gap at the discharge end of the upper tray. Collecting bins 22, 23, 24 are provided for the various grades of material and a circulating air current is provided by a fan 9 connected in series with a dust-collecting chamber 27. The materials are fed from a hopper 21 and the lighter upper layers are directed into the bin 22, the heavier materials falling through the gaps on to the tray 43 being subjected toretreatment and subsequently delivered to the lower member 29 where a separation into the heaviest materials, collected at 23, and the intermediate materials collected at 24 takes place.