GB833259A - Improvements relating to edge type filters - Google Patents

Abstract

833,259. Filters. STEVENS, R. J. Oct. 28, 1957 [Nov. 6, 1956], No. 33816/56. Class 46. [Also in Group XXVIII] Unfiltered liquid enters the ends of slots E, Fig. 3, exposed near two opposite sides of an "edge" filter consisting of a pack A, Fig. 2, of laminae, the superimposed slots E constituting "inflow lanes" to the filter. Bridges F, Figs. 3 and 4, are provided at intervals across the slots, but are vertically staggered as shown in Fig. 4. The liquid filters between the upper (rough) surfaces of the laminae and the lower (smooth) contiguous surfaces of adjacent laminae and emerges into slots D, Figs..3 and 4, collectively constituting "outflow lanes". These lanes communicate with port openings 8, 11 inporting plates 3, 4 respectively, Fig. 4, which openings provide access to channels 6, 7 and 9, 10 in upper and lower blocks 1, 2 respectively. Outlet pipes 12, Fig. 2, in block 1, and 14 (not shown) in block 2 are provided. Alternatively the normal filtration flow may be the converse of this. The laminae may be cut from a strip such as that shown in Fig. 6, which is etched both to provide the rough area G, Fig. 3, and to provide slots E and D and holes 17 which, on cutting the strip, form locating notches 16, Fig. 3, to co-operate with bolts 5, Fig. 2. To provide the communication of slots E with the space ambient to the pack, two sets of laminae are used, necessitating two strips of material. The strip of Fig. 6, wherein holes 17 are offset to the left, provides laminae of set C, Fig. 3, which extend to the right beyond the edge of the alternate laminae forming set B. Laminae of set B are prepared from strip having the holes 17 offset to the right. The preparation of the strip may be done electrolytically, e.g. by the etching unit of Specification 795,655, or by the process and apparatus of Specification 795,656 [Group XXXVI]. In Fig. 9 (not shown), the bridges F are each as thick as the remainder of the lamina and extend obliquely across the slots, being oppositely inclined in adjacent laminae and being vertically superimposed so as to form, in toto, a column of X's. Thus, where the bridges cross, a load-bearing column is provided, which strengthens the pack.