GB751133A - System of radial filtering surfaces - Google Patents

Abstract

751,133. Filters. ZDANSKY, E. A. March 19, 1954, No. 8101/54. Class 46. A radial filter assembly especially for use with filter aid is characterized in that the filter elements are arranged radially about a central filtrate collector space and have the form of quadrangular plates each consisting of two parallel and mutually supported filter membranes the interstice between which is closed on the three outer edges of the quadrangle, and on the edge towards the centre of the radial arrangement is provided with filtrate openings, the latter edge being widened by distancepieces which in the assembly of the elements form a closed tubular jacket with vertical axis surrounding the central filtrate collector space, the jacket being held together at top and bottom by clamping-rings. Filter leaves each comprise a coarse supporting mesh 1, Fig. 3, covered on both surfaces by fine-mesh wire cloth 2, 2a, the interstice Z being closed on three sides, Fig. 1 (left-hand side), by a metal strip 3 or a fused-on layer of metal. The inner edge is provided internally with packing-strips 6 projecting for from 2 to 20 mms. outwardly to prevent penetration of filter cake into the angles between the leaf and two bars 4 (acting as distance-pieces) between which it is gripped. The bars 4 alternate with the leaves and are reduced in thickness at top and bottom, as shown, so that they can be held in place to form a tube by rings 20, 21, which are drawn towards each other by a filtrate discharge pipe 24 welded at the top to a flange 25 (to which the ring 20 is also welded) and secured by screws 26 at the bottom to a flange 27 on which the ring 21 is seated. Packings 9, Fig. 3, and 22, 23, Fig. 1, are provided. In Fig. 4 and the righthand side of Fig. 1 stainless steel wire cloth sheets 12, 12a, are welded to a trapezoidal frame 11 and to inclined strengthening and dividing cross-bars 15, each apertured at 16 to ensure escape of air from the compartments into which the bars divide the leaf when liquid to be filtered is admitted to a vessel in which the filtering unit is located. Distance-pieces 17 are welded, one to each side of the inner edge of each leaf. The plates of Fig. 3 are suitable for use with a thick layer 7 of filter aid such as asbestos and cellulose producing a high pressure differential, while with those of Fig. 4 kieselguhr 18 is used.