GB679133A - Improvements in or relating to electrostatic precipitators - Google Patents

Abstract

679,133. Electrostatic precipitation. WESTINGHOUSE ELECTRIC INTERNATIONAL CO. Nov. 15, 1949 [Dec. 1, 1948], No. 29195/49. Class 39 (i). An electrostatic precipitator comprises a screen of meshed filaments of relatively high electrical resistance held in a frame of relatively low electrical resistance, and a high voltage is established between a point in the interior of the screen and the frame. The electrified screen is placed transverse to the gas flow. Several screens may be incorporated in a dust collector cell removable from a casing, and preceded by an ionizer. In one embodiment, Fig. 8, the screen is of zig-zag outline, and comprises meshed filaments 40 held in frames formed by horizontal spaced zig-zag wires 38 and vertical spaced straight wires 39 located midway between the apices of the fold. The high voltage is applied between wires 37 which contact the centre of alternate screen sections at apices of the folds, and the frame wires 38, 39. In a modification, Fig. 13, the wires 37 form with further vertical spaced straight wires 44, frames containing screen sections whose centres are contacted by the wires 38. In another embodiment, Fig. 9, the filamentary screens comprise flat sheets having spaced, rounded projections 52, 53. The projections on adjacent sheets are staggered with respect to each other, and space apart the flat areas. The screens may comprise asbestos fibres, paper or cloth base filaments, or threads impregnated with a liquid containing electrically conductive particles such as carbon or metallic salts, or filaments of semi-conductive plastics, such as urea-resin plastics. The openings between the filaments may be circular, square or hexagonal, and the filaments may be coated with an adhesive to aid in holding the deposited particles. Specification. 475,443 is referred to.