GB1207257A - Improvements in centrifuges - Google Patents

Abstract

1,207,257. Centrifugal separators. C. KERBY. 13 Dec., 1968 [14 Dec., 1967], No. 59920/68. Heading B2P. A centrifuge for removing suspended solids from a biological fluid, Figs. 1, 3 and 4, comprises a balanced head, e.g. a shaft 10, mounted for rotation in bearings 11, 12 and having at least one radially extending arm 16 with a cell 21 mounted at its extremity to receive solids-laden fluid from a source, e.g. an animal, through a fluid-tight bearing 18, 19 coaxial with the bearing 12, means for the discharge of solids-free fluid from the cell through a second fluid-tight bearing 27, 28 coaxial with the bearing 11, and means for discharging separated solids from the cell 21. The shaft 10 is driven by a belt 14 through a variable speed motor 15. The source of solids-laden fluid is connected through tubing to a stainless steel tube 18 over the end of which is rotatably fitted a P.T.F.E. tube 19 which passes through a bore 20 in the shaft 10 and through the arm 16 into the interior of the cell 21 which is provided at, its apex with a solids-discharge aperture 25 normally sealed by a spring-biased valve member 26 which is intermittently opened by a solenoid operated cam 30. The solids-free fluid passes from the cell 21 through a P.T.F.E. tube 27 rotatably fitted over a stainless steel tube 28 which may be connected back to the source. The tubes 18, 28 may be mounted in heat sinks 29 to reduce the heat produced by friction between the P.T.F.E. and stainless steel tubes; the sinks 29 may be rotated by separate drive means to further reduce friction. The shaft 10 may carry a further arm 17 which, as shown in Fig. 6, may be provided with a carrier 34 for one or more cells 3 which may contain specimens on which the effect of the solids-free liquid may be studied. Each of the cells 31 communicates with the cell 21 in arm 16 via tubes 32 and discharges fluid via tubes 33 to output tube 27. An alternative cell 36 by means of which the separated solids may be connected is shown in Fig. 9. The cell has a floor 37 and a flexible membrane 38 spaced therefrom. In use the cell is fitted to arm 16 and two-way cocks are fitted to the inlet and outlet side of the centrifuge at 18 and 20. Collection of separated solids takes place on the membrane 38 which distends into cavity 29 under centrifugal force. For removing the collected solids the centrifuge is stopped, the two-way cooks are operated in the other direction and a pressurized stream of fluid is introduced through the outlet side of the centrifuge, mixes with the solids which have been disturbed by the membrane result ing its original flat shape and jet them out through the inlet side into a receptacle.