GB1173417A - Centrifugal Separator - Google Patents

Abstract

1,173,417. Centrifugal separators. ALFALAVAL A.B. 20 Aug., 1968 [23 Aug., 1967 (3)], No. 39705/68. Heading B2P. In a centrifuge having a screw conveyor 2, Fig. 1, for sludge discharge overflow outlets 5 for purified liquid are formed in separate members 4 which are journalled in the centrifuge rotor 1 for rotation therewith and for adjustable rotation relative thereto so as to move the overflow outlet 5 between radially inner and outer positions, common adjustment means being provided for synchronous rotation of all the members 4 through the same angle. As shown in Fig. 1, the outlet 5 of each member 4 is eccentric relative to its axis of rotation. Each member has gear teeth 6 which are in mesh with a gear ring 7 at one end of a sleeve 8 having helical splines 9 at its other end. The rotor 1 is connected to a sleeve 10 having helical splines 11 of opposite direction to the splines 9. A sleeve 12 has internal splines in engagement with the splines 9, 11 so that when the sleeve is axially displaced the gear ring 7 rotates relative to the rotor 1 thereby angularly adjusting the members 4 relative to the rotors as to alter the radial position of the outlets 5. Instead of a sleeve 12 an externally splined spindle parallel with the rotor axis may be provided. Other means for rotating the gear ring 7 relative to the rotor 1 include a spur gearing arrangement, Fig. 3 (not shown) and a level gearing arrangement, Fig. 4 (not shown). In a modification. Fig. 5, each member 4 is in the form of an L-shaped pipe portion, the extremity of the channel 5a therein defining the liquid level in the rotor and permitting, depending on its position within the rotor, complete emptying of the drum. In a further modification, Fig. 6, each member 4 is formed with a through bore 5c opening into an annular recess 4a in the member, the recess 4a forming with the rotor an annular channel 5a which is in constant communication with a liquid outlet channel 5b in the rotor. In each of the two modifications, the rotor 1 or the members 4 may be provided with means arranged in one position of the members 4 to block the channels 5a entirely so as to direct all substances supplied to the rotor to the sludge outlets. Further, the channels 5b may be formed outside the rotor end wall. The recesses 4a may alternatively be provided in the rotor end wall. In a still further modification, Fig. 8, the member 4 is provided with an approximately 180‹-extending flange which normally closes a radial opening 1a in the rotor. Counterclockwise rotation of the member 4 from the position shown allows the radial position of the outlet 5 to be adjusted while keeping the opening 1a closed whereas clockwise rotation will cause the opening 1a to be uncovered thus enabling emptying of the rotor.