GB817440A - Replaceable filter elements - Google Patents

Abstract

817,440. Filters. NUGENT, C. D. Aug. 21, 1957, No. 26410/57. Class 46. A bag filter element 18, Fig. 2, is formed by folding a piece of fabric (preferably cotton or wool) into elongated tubular form, seaming the adjacent edges at 27, and seaming the ends at 27a. A wire mesh tube 21 maintained cylindrical by flanged bushings 22, 23 and optionally by one or more rings 52 is located within the bag between apertures 26, 26a, and at each end of the tube the part of the bag around the edges of the appropriate aperture is clamped to the tube by an annular sealing ring (33 or 47, Fig. 6) retained on a sleeve (31 or 46) by a beaded intermediate portion (32 or 32a) of the sleeve, and the edge of the aperture is held against the inside of the adjacent bushing 22 or 23 by the sleeve. The upper sealing ring 33 acts through a plate 34. A corrugated wire screen 28, (see also Fig. 4), passing behind the tube 21 (or two screens abutting the tube) is preferably introduced into the bag before seaming. When assembly is complete the two ends of the bag are wrapped around the tube 21 with two lengths of corrugated wire screen 43, 44, Fig. 4, interposed between adjacent convolutions, and the whole cartridge introduced into a cylindrical shell 10, Fig. 6, on to which a cover 11 is then secured by bolts, (not shown). The bag is distended in the manner shown in Fig. 4 by oil for filtration introduced under pressure and passing down a bore 37 into the upper sleeve 31, (which is foreed into the bore when the cover 11 is put on) and thence into the tube 21 and bag 18. The cartidge is of such a length that when the upper beaded portion 32 is located in a recess 37a in the cover 11 and the lower sleeve 46 is in contact with the shell 10, the rings 33 and 47 are compressed. Filtrate leaves at 15, Fig. 6. A spring-pressed by-pass valve 46a, Fig. 6, is provided. In Figs. 1 and 5 (not shown) the valve is located, instead, in the cover 11.