GB802390A - Rotary filter with a pre-filtering layer - Google Patents

Abstract

802,390. Filters. S. A. ECRE-MEUSES MELOTTE. July 19, 1957, No. 22930/57. Class 46. Unfiltered liquid is introduced by a pipe 5 to a trough 4 in which a drum 1 rotates clockwise, Fig. 1. A suspension of, e.g., calcium carbonate, infusorial earth, shredded cellulose or potato starch is discharged along a pipe 10 from a vat 13 by a pump 15 to a V-shaped chamber 9, Fig. 2, constituted by a fixed plate 7 and a plate 8 slidable so as to vary the gap between them. The suspension falls on to a cylinder 6 rotating counter-clockwise and preferably having a non-smooth surface, and is projected thereby on to the drum 1 in the form of jets or sheets. The cylinder 6 is mounted on a support 21 which also carries a knife 16 and circular brushes 17 and is movable by a motor-operated screw 22 to vary the depth of cut and the amount of filter aid deposited. Excess suspension is collected at 11 and returned at 12 to the vat 13, Fig. 1. A roller 18 on slide tracks 19 equalises and compresses the filter aid layer. The brushes may be replaced by one or more endless chains carrying scrapers. In Fig. 2A (not shown), the cylinder 6 rotates clockwise, and the plate 7 occupies approximately the position formerly occupied by plate 8 (which is now dispensed with) and carries a vertical overflow weir behind which the suspension is fed from under a downwardly-depending baffle by the pipe 10.