Patent GB-1346362-A (GB)
Title: Centrifugal separator
IPC: B04B5/02
Filed: 1971-10-20
Abstract: 1346362 Centrifugal separator W H PECK 20 Oct 1971 48747/71 Heading B2P  A centrifugal separator for dehydrating solids contained in a slurry comprises a horizontal carrier 12, Figs. 1, 2 and 4, which is rotatable about a central vertical axis. A plurality of separator baskets 16 are eccentrically and rotatably mounted on the carrier in circumferentially spaced relationship for rotation about respective vertical axes and for orbital movement about the axis of the carrier. Each basket includes a horizontal platform 26 adapted to receive slurry thereon. Distribution channels 72 rotatable with the carrier 12 lead to the central regions of the baskets for depositing slurry therein. A plurality of imperforate slurry-restraining walls 24 project upwardly from each basket platform 26 and present concave surfaces which face generally inwardly of the platform. Thus, each time an individual wall assumes an outside ecliptic position with respect to the axis of the carrier and the axis of the basket, slurry will be flung by centrifugal force in a direction radially outwardly of the carrier and the solids therein caused to settle toward and against the concave surface of side wall while a diminishing solids gradation will take place radially inwardly of both the basket and the carrier. When such wall progresses toward an inside ecliptic position, the settled solids on the concave wall surface will be dislodged by centrifugal force and flung from the basket. A first opening 30 is provided in the platform 26 between the concave surface of the wall and the axis of the basket at a region of low solids density radially remote from said concave surface for discharge of substantially solids-free clear liquid from the basket. A second opening 34 is provided between said concave Surface and the axis of the basket at a region of high solids density close to the concave surface for discharge of semi-clear liquid from the basket. A first annulus L underlying the carrier and common to all the baskets serves for the discharge of the liquid issuing from the openings 30. A second annulus SS also underlying the carrier and common to all the baskets serves for the discharge of the semi-clear liquid issuing from the openings 34. A third annulus S serves for the discharge of solids flung from the baskets. Means M, 79, 14, 80, 81, 83 are provided for rotating the carrier 12 at a relatively high speed, e.g. 1200 r.p.m. and means 14, 154, 156, 158, 162, 164, 77, 166, 168, 172 are provided for rotating the individual baskets at such relatively low speed, e.g: 6 r.p.m. that no appreciable centrifugal force is imparted to the slurry deposited therein other than that which is imparted thereto by rotation of the carrier. A hood 60 overlies the carrier 12 and the baskets 16 and carries a feed hopper 62 which communicates with a rotatable distribution manifold 68 which is driven in unison with the baskets 16 and has radially diverging branch conduits 70 which define the slurry distribution channels 72. The main drive shaft 14 for the carrier 12 is continuously driven by an electric motor M through a belt and pulley arrangement 79. A tubular drive sleeve 81 keyed to the shaft 14 has an annular flange 83 which supports the carrier 12. A drive sleeve 80 surrounds the sleeve 81 and is bolted to the flange 83. The carrier supports bearing assemblies 82 each of which supports a basket drive hub 18 which at is upper end supports the associated basket platform 26. The slurry restraining walls 24 which project from each platform 26 are formed by involute vanes which are clamped between the platform 26 and a top wall 84 by bolts extending through tubes 140 welded to the convex sides of the vanes 24. The semi-clear liquid slides along the vanes and becomes trapped in hook-like end portions 32 on the vanes and pass from the baskets via the openings 34 in the respective basket platform 26. The openings 34 are flushed by impulses of water supplied to the vane portions 32 by pipes 122 connected to elbow fittings 135 which communicate with radial ports 136 in a porting ring 137 which rotates with the top wall 84 so that each time one of the ports 136 moves into register with a water pocket in a non-rotatable outer bearing housing ring 116 a quantity of water will be injected into the associated pipe 122. The water is supplied through a pipe 110 swivably connected to branch pipes 114 which communicate with passages 118 in the ring 116 leading to the water pocket. Each basket top wall 84 carries an upper cup-shaped hub 88 which is rotatable in a bearing assembly 90 supported on an upper carrier plate 92 at the upper end of the drive sleeve 80. The plate 92 supports arms 93 secured to the branch conduits 70 of the distribution manifold 68. Each conduit 70 extends through an opening 86 in a top wall 84. The hubs 18 of the baskets 16 are driven from the drive shaft 14 through gears 154, 156, 162, 164, a drive sleeve 77 and a system of epicyclic gears 166, 168, 172. The nearly dry solids which are flung from the periphery of the baskets pass over and across a horizontal shelf portion of an outer stationary wall 188 and are flung a rotating wall 192 from whence they fall by gravity through the annulus S. Solids which accumulate on the wall 192 are removed by scrapers 200 bolted to the wall 188 and bearing against the wall 192. The latter is driven at a relatively slow speed by an auxiliary motor M 2  through gearing 204, pulley 208, belt 210 and a drum 212 which is secured to and encircles the wall 192. The wall 192 and the drum 212 are rotatably supported by horizontal and vertical rollers 220 and 222 respectively.