GB727091A - Improvements in and relating to filter presses - Google Patents

Abstract

727,091. Filters. GEIGY AKT.-GES., J. R. Feb. 11, 1953 [Feb. 12, 1952], No. 3786/53. Class 46. In a filter press in which the filter press plates consist of a framework having holes for the peripheral. admission of feed slurry and washing liquor and discharge of mother liquid, and a sheet-form central plate strong enough to withstand only the pressure difference across it, and with uneven surfaces on both sides, the plates are separated by an elastic insert piece consisting of one part located in the admission hole of the frame and serving to fix the insert piece to the filter press plate and a second part serving as a channel from the frame to the press interior and serving also to keep those portions of the filter cloths in contact with it pressed tightly against the filter press plates. A filter press plate comprises a demountable framework 15a, b, c, Fig. 1, enclosing a plate 25 consisting for example of corrugated iron sheet having a thickness of from 1 to 3 mms. A feedhole 28, counterbored at 29, Fig. 3, is provided for liquid to be filtered, and communicates by channels 30 with the spaces on either side of the central plate 25. Inlets 32, Fig. 1, and borings 33 for washing-liquor and air are also provided. The filter cloth is preferably such as can be suspended, inverted-U fashion, over the upper member 15b so as to cover both sides of the plate, and has pairs of holes corresponding to 28 and 32. It is partly retained in place, and adjacent filter plates are juxtaposed in a fluid-tight manner by an insert piece 31, Fig. 3, which may comprise an annular rubber disc 34, Fig.7, having a slot 39 providing communication with the channels 30 of two adjacent plates, and secured by rubber rods (not shown) between frusto-conical annulae 35, 36, one of which has a stem 37 surrounded by a rubber sleeve 38 and adapted to fit in the hole 28. The insert piece may be wholly of rubber and in one piece, Fig. 10. The slot 42 is in that case strengthened by rigid tubing 44. Where the counterboring 29 is omitted the insert may comprise a short piece of tubing with a smaller piece depending from it. In Fig. 13 the insert piece comprises an open channel member 49 provided at one end with a dependent member 50 having an elliptical bore 51 and at the other with a hook 52 which fits into a slot provided in the opening 28 of the filter plate.