GB789323A - Improvements in or relating to filters for liquids - Google Patents

Abstract

789,323. Liquid filters. VICKERS-ARMSTRONG (ENGINEERS), Ltd. Feb. 15, 1956 [Feb. 23, 1955], No. 5487/55. Class 46. A straining cartridge, for use with filters for oil &c. and providing a hollow interior or core, comprises a pile of straining elements each consisting of a ring-like member made up of a pair of annular casings spaced apart axially and formed with perforated faces between which and the inner and outer walls of the casing felt &c. is accommodated, the elements being assembled coaxially, face to face with spacing means between the faces of adjacent elements to provide a laminated cartridge which, when positioned in the filter body defines an encircling outer chamber and an inner chamber constituted by the core so that oil &c. can be filtered while flowing from one chamber into the spaces between adjacent elements, thence through the filtering medium and into the other chamber. Liquid to be filtered enters a casing 1 and flows to the exterior of a stack of filter elements 14 the hollow core of which communicates with an outlet 4 in a cover 3 for the casing 1. The elements 14 are separated from one another by distance pieces 32, Fig. 3, having radial arms 33 providing between them sector shaped recesses 34, into which the liquid to be filtered flows. Four of the arms are extended to receive holding rods 38 which prevent rotation of the distance pieces 32. Each element (shown exploded in Fig. 4) consists of a keeper ring 22 having an internal rib 23 to support upper and lower annuli 24 separated by distance pieces 31. The outer parts of the annuli are perforated at 25 and each annulus has a stepped central portion 26. Beside the step lies a ring 29 of felt or other filter material which is held against the perforated part of the adjacent annulus 24 by a recessed annular member 28. Rods 17 passing through lugs 30 on the annuli 24 are adapted through nuts 18 to clamp the elements and distance pieces 32 together. The rods 17 are mounted in end covers 15, 16 rotatably mounted in a lower support 13 and the cover 3 and keyed to a shaft 6 rotatable by a handle 8 to make the arms 33 scrape the surfaces of the adjacent elements 14. The distance pieces 32 may, however, be mounted non-rotatably in respect of the elements 14 and cleaning be effected by back-washing. For this purpose the inside chamber 35 communicates through the elements with a vertical nozzle 41 held closely against the outer surface of the elements 14 by a spring- pressed bar 43 and of a width to mask a single sector 34. The nozzle leads to a valved outlet 45, 46, the pressure in the inside chamber being sufficiently above that in the nozzle to compel flow therethrough. The pile of elements is rotated continuously or step by step to bring every sector 33 opposite the nozzle 41. The nozzle may carry one or more scrapers 48. Specification 564,032 is referred to.