GB478434A - Improvements in filters - Google Patents

Abstract

478,434. Filters. CAMPBELL, R. C. July 22, 1936, No. 20275. [Class 46] An inward-flow rotary drum filter has one end projecting through the wall of the tank containing the liquid to be filtered and the filtrate is discharged directly near the periphery of the drum from the filtrate space or channels within the filtering-medium. Filtrate is discharged from filter sections formed by longitudinal ribs 6 at the periphery of a rotary drum 1 through passages 10 in a rim 8 at one end of the drum. This end of the drum which projects through the wall 20 of the tank 12 is supported by a spider 4 from a trunnion 5. The trunnion 5 extends through the walls 30, 31 of a filtrate reservoir and is supported by a bearing 33. The other end of the drum is supported by a plate 2 from a trunnion 3, passing through the end 15 of the tank 12, supported by a bearing 17 and provided with a driving pulley 19. The passages 10 deliver filtrate from the immersed filter sections directly into the filtrate reservoir. As each section rises from the liquid the end of its passages comes under an arcuate suction box 35 connected by a barometric tube 41 to the lower end of the filtrate reservoir. The box 35 is held against the end face of the rim 8 by springs 45. A jet of water may be directed into the box 35 to assist the suction. Alternatively a fan may be connected to the upper end of the suction box for removing air. Joint is made between the rim 8 and the end 20 of the tank 12 by means of a leather band 23 the tension of which can be adjusted. Any liquid leaking at this position is collected in a chamber 27 and returned to the tank 12. A filtrate reservoir and suction box 35 may be provided at each end of the drum.