GB1022856A - Centrifuge with conical centrifuge drum - Google Patents

Abstract

1,022,856. Centrifugal strainer separators. KRAUSS-MAFFEI A.G. Jan. 2, 1963, No. 231/63. Heading B1D. A centrifuge has a drum widening conically to the upper open discharge end, said drum being drivable about two intersecting axes having a positively adjustable angle of intersection. The angle of intersection may be adjustable during the running of the centrifuge drum, (Figs 1-4), or only while the apparatus is stationary, Fig. 5 (only Fig. 1 is reproduced). In Fig. 1, material to be centrifuged passes through hoppers 6, 7 to the lowest part of the drum 3. Filtrate passes through sieve jacket 2 and is conducted by collar 8 to the space 9. Solid material passes over the discharge end 1 of the drum 3 into the chamber 11. The centrifuge drum is driven by the two concentric drive shafts 12, 12a arranged to rotate at slightly different speeds by the action of the belts 15 connected to pulleys 17 on either end of the shaft of motor 16. By means of chain wheel 25 and a chain drive system (not shown), drive shaft 12 and its mounting housing 21 can be displaced axially. Hollow cylinder 26 and roll 27 together form a roll joint 29, rotatable in only one plane, so that on rotation of joint 29 the centrifuge drum rotates about the axis of the drive shaft 12 and the axis of the drum 3, the point of intersection of the two axes being placed in the centre of gravity of the drum 3 to reduce the want of balance of the drum. Covers 30 prevent axial displacement of roll 27. The bottom 4 of the drum 3 is secured by shaft strut 44 on the top 43 of the member 41, which with the bolt 39 forms one fork of a cardan joint, the slotted shaft end 37 forming the other fork. Adjustment of the angle of inclination of the centrifuge drum axis in relation to the vertical and thus to the axis of the drive shafts 12 and 12a is effected, while the centrifuge is in operation, by lifting the drive shaft 12 by means of the housing 21 so that the bolt stubs 45 slide in the oblique slots 46, rotating the roll 27 and the centrifuge drum 3 in a counter-clockwise direction. A non-rotatable ball-and-socket joint may replace the roll joint, or a joint having a ball rotatable in two mutually perpendicular planes may be used. In Fig. 4, the adjustment of the angle of intersection is effected hydraulically. Hollow cylinder 26 is arranged asymmetrically on drive shaft 12a and the space 47 between roll 27 and the drive shafts 12 and 12a is filled with liquid. On raising the shaft 12, liquid is forced into the projecting space 47 of the hollow cylinder 26 and the part of the roll 27 situated in this space is lifted, so that the drum axis is pivoted in a counter-clockwise direction. In Fig. 5 the adjustment of the angle of intersection can be effected only while the centrifuge drum is stationary. Hollow cylinder 26 has two threaded bores 48 into which a set screw 49 which retains the roll 27 can be screwed. In Fig. 6, the conical edge of the reception chamber 11 is replaced by a hollow spherical ring 50 the width of which is adapted to the maximum possible drum movement and in which the solid discharged material is received. Discharged material can be removed from this ring through an outlet 51 connected tangentially to ring 50. Clearing scoops 52 can be arranged on the drum edge 53 to facilitate emptying of the ring. To enhance drying of the solid, drum 3 can consist of two jacket ring parts 54 and 55 connected together, part 54 adjacent the bottom 4 having a smaller angle of opening than part 55. Variation of the angle included by the drum axis and the drive shaft axis ensures that the angle of repose of the material in the discharge region is attained and thus permits separation of materials of different angles of repose with the same centrifuge drum.