GB1190179A - Centrifuge Construction - Google Patents

Abstract

1,190,179. Centrifugal separators. PENNSALT CHEMICALS CORP. 2 Dec., 1968 [21 Dec., 1967], No. 56985/68. Heading B2P. In a centrifuge for separating solids from liquid and having a screw conveyor for discharging the solids through ports in the centrifuge bowl and a feed tube 36 for delivering feed material to a feed chamber 38 within the conveyor hub 40 where the feeed material is directed by an accelerator plate 52 towards one or more apertures in the hub leading outwardly into the separating chamber 46 in the centrifuge bowl, the solids are prevented from accumulating in the feed chamber 38 by means of a baffle plate 74 which is disposed in the chamber 38 to deflect the feed material through the apertures 72, thereby avoiding erosion or twisting of the feed tube by the accumulated solids. The chamber 38 is provided with a stainless steel liner 70. The apertures 74 are helically arranged between the flights 42, 44 of the conveyor. The baffle plate 74 is inclined to the conveyor axis and is provided at its inner periphery with a flanged annular member 78 which cooperates with a stationary flanged annular member 76 on the feed tube 36 to deflect inwardly flowing feed material towards the aperture 72, the baffle plate 74 may be flat, curved or of single conic section or may have a helical periphery. The accelerator plate 52 is fitted centrally with a radial vane assembly 56 which cooperates with guide members 58 on the plate to impart radial and tangential velocity to feed material as it discharges from the feed pipe 36. The feed chamber 38 is separated by means of a partition 48 and a seal 62 from an annular space 64 which may serve as a rinse chamber into which washing liquid may be introduced via a tube 66 and flows, with aid of accelerator vanes 65, through at least one radial passeway (shown closed by a plug 68) into a solids-discharging frusto-conical portion of the separating chamber. In a modification, Fig. 3 (not shown), the apertures (72) in the hub are fitted with wear sleeves (84) projecting inwardly and outwardly of the apertures. The flange (77) on the annular member (76) is made of elastomeric material to facilitate its insertion with the feed pipe through the seal (62). In a further modification, Fig. 4 (not shown), the screw conveyor is provided with a double-helical screw flight and the apertures (72), (72') are arranged in a double helix. The baffle plate is made of two parts oppositely inclined relative to the centrifuge axis, each serving to deflect feed material through a different one of the two series of apertures. The centrifuge may be vertically mounted and the bowl may be wholly frusto-conical or partly cylindrical and partly frusto-conical.