Patent GB-1449926-A (GB)
Title: Cartridge centrifuge
IPC: B04B3/00
Filed: 1974-02-15
Abstract: 1449926 Centrifugal separators DONALDSON CO INC 15 Feb 1974 [28 Feb 1973] 7023/74 Heading B2P A centrifuge for separating particulate matter from a fluid comprises a stationary enclosure 12, Figs. 1 and 2, having fluid inlet means 44 and outlet means 16, a rotor 23 mounted within the enclosure for rotation about a predetermined axis, the rotor being constructed to receive uncleaned fluid from the inlet means and to deliver cleaned fluid to the outlet means and defining about the rotational axis a plurality of concentric passages for the fluid, and means associated with the rotor for causing fluid flowing therethrough to attain maximum angular momentum after leaving the plurality of passages. The rotor 23 is secured by screws 25 to a support plate 22 on the end of a rotatable shaft 19. The upper edge portion of the side wall 26 of the rotor is provided with threaded bores which receive Allen screws 27 having liquid flow restrictive bores 28. An annular top plate 29 is removably secured to the side wall 26. An annular baffle plate 32 is spacedly suspended from the plate 29 and defines with the side wall 26 a flow restrictive annular passage 35 disposed at the maximum radial point within the rotor 23. An annular member 36 of L-shaped cross-section is supported on the underside of baffle plate 32. The rotor also comprises a removable cartridge 37 defined by a liner tray having inner and outer cylindrical walls 38a, 38b and a bottom 38c. Disposed within the tray above spacers 38d are four particle separation stages or cartridge elements 39a-d each consisting of a flat layer 41, Fig. 5, of liquid impervious material, e.g. treated heavy paper or flexible cardboard, which is alternately wrapped with a corrugated layer 42 of the same materials, the size of the corrugations determining the spacing between the layers 41 and hence the depth of liquid flow therethrough. The separation stages 39a-d have progressively smaller spacing between the layers 41 to accommodate particles of varying size and shape. Stages 39a and 39d rest respectively on stages 39b and 39c, and a liquid impervious cylindrical casing 43 sealingly engaged with annular member 36 is disposed between the stages 39a, 39b and 39c, 39d. In operation, liquid to be filtered is delivered from a spout 44 into the cup defined by the inner wall 38a of liner tray 38 and, as indicated by the arrows, moves successively over the wall 38a; through the stages 39a-d, where the particulate matter is separated out and settles on the outer walls of the passages defined between the layers 41; through the annular passage 35 at which it reaches maximum angular momentum; between the baffle plate 32 and top plate 29; around and over the plate 29; and finally downwards between the rotor 23 and the surrounding casing 12 for discharge through a tangential outlet 16. The restrictive bores 28 serve to drain liquid from the rotor after the supply through the spout is shut off for servicing or cartridge replacement. In a modification, Figs. 3 and 4 (not shown), there are no superposed separation stages, the latter being concentrically arranged and extending the whole length of the rotor.