Patent GB-222186-A (GB)
Title: Process and apparatus for separating intermixed divided materials of different specific gravities
IPC: B03B4/02
Filed: 1923-06-21
Abstract: 222.186. Peale, R., Peale, R., and Peale, R. June 21, 1923. Separating by shaking-apparatus; pneumatic separating.-In a process for separating intermixed divided materials of different specific gravities the materials are stratified on a pervious table by rapidly reciprocating the table and forcing air through them under pressure and the lower stratum of heavy material is caused to travel in a substantially non-diverging stream and the upper stratum of light material in directions diverging over an extended area. The apparatus described comprises a pervious table 40 shaped as shown in Fig. 1, having a narrow rear part 41, to which the mixed materials are fed, and sides diverging to the points 51, 52 and then converging to the points 53, 54 at the front end. The feed end of the table is closed on three sides by walls 42, 43, 44. and the walls 47, 48 on the diverging sides are of decreasing depth and become flush with the surface of the table at the area 49, 50. Parallel separating walls 45 extend inwardly and forwardly leaving a central unobstructed area. These walls are preferably inclined inwardly and of increasing depth in the forward direction.. Perforate or solid shelves 61. 62 collect the light material which spills into shoots 63, 64 and is discharged by shoots 65 which are angled to form an air seal with the materials. The forward end of the table comprises a solid box structure 77, Fig. 7, open at its front and rear sides, and enclosing a casing 86, made of pervious material also open at front and rear and spaced at the sides and top from the box 77. The rear of the box is closed by a hinged and weighted gate. 93 for the discharge of the heavy material under a predetermined pressure and the arrangement of the pervious inner casing is designed t'o permit the air to play through the materials collected therein in a rearward direction to prevent discharge of any light material that may have collected at this point. Material of an intermediate specific gravity is collected bv adjustable boards 103, 104 and delivered by angled shoots 106 forming an air-seal. A longitudinal partition 99 may be disposed rearwardly of the box 77. The degree of perviousness of the table is preferably arranged so that the pressure decreases outwardly from the centre and increases in the forward direction. In the construction shown in Fig. 3, the air pressure is supplied to a fixed chamber 125 co-extensive with the table and having a flexible air-tight connection 123 therewith. An adjustable pivoted plate 132 regulates the supplv of air to the different parts of the table. The table is sup. ported by links on a stationary frame the inclination of which is adjustable and is preferably set so as to incline upwardly towards the front. The. actuating mechanism consists of a cam 162 shaped so as to provide a slow backward movement against compression springs and a rapid forward movement which is suddenly checked by impact on abutments 190 the position of which is adjustable to vary the amount of movement of the table. The top of the table is covered by an expansion chamber 240 with a flexible airtight connection 239 so as to collect the dust carried off by the air. The material is fed from a hopper 3 by a reciprocating plate 7 through an opening 8 controlled by a slide 9 and falls through a fixed shoot 27. In a modification shown in Fig. 11, the table has a flexible air-tight connection to a stationary air-chamber 284 into which the air is drawn through the table by the suction of a fan 292, the dust being collected in an expansion chamber 313. The top of the chamber 284 has a movable part 298 connected to the main part by a flexible air-tight joint and adjustable vertically by cables 299 and also having a variable lateral inclination to regulate the air currents. The part 298 may be in two parts hinged together longitudinally so as to be inclined relatively to each other. The discharge at the forward end is through a passage 255, Fig. 15, having solid or pervious sides and a top plate 256, a slide 258 being provided to control the air currents. The hinged and weighted door 259 is of pervious material with an air-regulating slide 263.