Patent GB-990832-A (GB)
Title: Centrifuge apparatus
IPC: B04B15/08
Filed: 1963-02-15
Abstract: 990,832. Centrifugal separators. BECKMAN INSTRUMENTS Inc. Feb. 15, 1963 [March 27, 1962], No. 6184/63. Heading B2P. [Also in Division F2] In a continuously-operated centrifuge comprising a rotor 13 driven from one end, Fig. 1, a liquid to be clarified is conveyed to, and the clarified liquid removed from, the rotor through conduits 79, 78 which constitute a shaft 77 Figs. 5 and 7, extending axially from the other; end of the rotor, and communicate with passages 154, 156, 168, 171, 172 formed in a rotary member 153 and non-rotary members 162, 175 of a face-to-face seal, the members 162, 175 being slidable axially and urged against the member 153 by means of a hydraulic device 186, 187, Fig. 11, which is inserted between the member 175 and the centrifuge frame and tends to increase in axial dimension when liquid pressure is applied to it. The seal member 153 is secured to the conduit 79 and is sealingly surrounded by a housing 160 secured to the conduit 78. The members 162, 175 are surrounded by a cylindrical shell 161 which provides a chamber 163 for coolant around the member 162. Feed liquid is introduced through a tube 173 and clarified liquid removed through a tube 169. The hydraulic device comprises a piston 181 slidable in cylinders 183, 184 formed in the members 186, 187. The feed liquid is introduced through an inlet 191 to act on the piston and leaves through an outlet 192 conj nected to the tube 173 and, after passing through the centrifuge, the clarified liquid enters through a tube 193 connected to the tube 169 and finally leaves through the outlet tube 194. Due to the difference between the feed and clarified liquid pressures the members 186, 187 tend to be forced apart and, by their actions throw ball and socket joints against an adjustable screw 199, Fig. 2, and the member 175, urge the member 162 into sealing contact with the member 153. A spring 195 between the members 186 and 187 maintains sealing pressure under low feed pressure conditions. The seal assembly is enclosed in a guide member 150 to which a nozzle 206 is connected to spray water on to the sealing members, the water being removed through an outlet 207. The member 150 is secured to a member 120 in which is received a bearing 121 for the shaft 77 including an oil-lubricated porous sleeve 126 and a chamber 125 for coolant provided between a bearing sleeve 124 and a sleeve 122. The member 120 is resiliently supported on a housing 107. A spring-pressed sleeve 131 provides a vacuum seal between the member 120 and the support 107. The housing 107 is bolted on to a flange 106 threaded into a door 16 on top of the rotor housing and incorporates a sleeve 111 secured in a recess 109 by an insulating ring 112 and sealing rings 113, 116 and surrounding a guiding member 76 for the shaft 77 secured to the top of the rotor bowl 41, Fig. 5, and surrounded by a bearing 116A serving to damp vibrations. The sealing and bearing assembly is surrounded by insulating material 200 secured to a shell 202 which may be made of two halves hinged together in a circumferential direction. The conduits 78, 79 are secured to the rotor through a head 83 which is provided with a passage 89 connecting the inlet conduit 79 to slots 58 in the rotor core 49 and passages 56 in the cover 52 of the rotor bowl and with a passage 84 communicating the outlet conduit 78 with passages 71, 72 in the core. The rotor is surrounded by a housing 21 forming a vacuum chamber 17 which may be provided with refrigeration coils 23. The core 49 is connected by pins 47, 48 to a spindle journalled in an oil-filled bearing 26 and driven through a belt 32 by a motor 34. The housing 21, the bearing 26 and the motor assembly are resiliently supported by springs 37 on a platform 36 in an outer housing 11. In a modification, the feed and the clarified liquid may be directed respectively through the conduits 78, 79 which communicate respectively with the slots 58 and the passage 72. In a further modification the clarified liquid is evacuated through the guiding member 76 which is provided at its upper end with a rigid hollow shaft surrounding the conduit 79. The hollow shaft sealingly engages a recess in a housing sealingly surrounding the rotary face seal member and provided with flow passages. A rubber bushing is interposed between the bearing sleeve 122 and the member 120 which in this case is rigidly secured to the housing 107. Specification 925,677 is referred to.