GB1023086A - Improvements in centrifugal or rotary dryers - Google Patents

Abstract

1,023,086. Centrifugal strainers. ETABLISSEMENTS POMPES GUINARD. Sept. 10, 1964 [Sept. 13, 1963], No. 37130/64. Heading B1D. In a centrifugal strainer comprising a rotary sieve drum 1 and a rotor 3 having generally helical blades, the rotor rotating within the drum at a slightly greater speed than the drum itself to urge solid material axially along the space between the drum and rotor during centrifuging, the said space is divided into zones which each contain helical portions 4 extending from the rotor to the drum 1 and blades 5 which extend only part way from the rotor to the drum. A slurry delivered to the space is thus alternately moved one zone axially by a portion 4, then spread over the cloth lining 2 of drum 1 by a blade 5, Fig. 2 (not shown). Portions 4 and blades 5 may be separate members and resiliently mounted on rotor 3. Alternatively a blade 5 in one zone may be an extension of a portion 4 in a preceding zone, Fig. 4 (not shown), and blades 5 may be resiliently deformable, articulated, serrated or otherwise shaped, Figs. 5, 6 (not shown). Some blades may be replaced by rollers, Fig. 7 (not shown), articulated on rotor 3. Slurry is delivered to the space by tube 6 and straight or helical passages 7 through the rotor 3, which open tangentially into drum 1. Liquid centrifuged from drum 1 in the first two zones is collected at 11 and recycled, being applied by channels 14 to layers of solids spread over the drum in later zones, to recover fine solids. Wash liquid or liquids are supplied to different zones by conduits such as 20, 21, and a wash liquid may be recycled from one zone to the next. Solids are discharged into a volute 22, in which resilient or particulated blades 23, carried by the rotor or drum, engage. Successive zones may be defined by steps on the drum 1 and rotor 3, and/or zones may be separated by annular projections on rotor 3, having grooves where material is transferred from one zone to the next.