GB947875A - Classifying screen - Google Patents

Abstract

947,875. Screen classifiers. R. HALSTRICK. Aug. 2, 1960, No. 26667/60. Heading B2H. In a screen classifier, having two relatively moving frames comprising parallel plate separating elements, the elements of one frame being interposed alternately with the elements of the other and the movement of the frame or both frames being such that each plate element thereof moves in a closed circular path lying in a plane parallel to the plate elements, the plates a, Fig. 4, of at least one frame are connected together in pairs for lateral rigidity, each plate or pair being laterally spaced from the other. In addition or alternatively the upper edges of the plates may be thickened as in Fig. 7 (not shown) to increase rigidity or the plates may have studs f, Figs. 5 and 6, laterally projecting between adjacent relatively moving plate surfaces to provide lateral support against buckling. The top edges of the pairs of plates may carry an interchangeable strip of fine mesh or perforated sheet forming a floor for the material to be classified, Fig. 3 (not shown). The top edges of the plates may also have sawtooth serrations and spaced apart transverse strips connected to the aligned short sides of the teeth joining the plates in pairs, Figs. 5 and 6, to move the material to be classified in a direction parallel to the plate length. In Fig. 13 (not shown) alternative forms of serration are illustrated. In an alternative form of classifying, Fig. 11 (not shown), the plates of one or both systems have slits therein to permit lateral passage of particles when the plates of one frame rise above the plates of the other, the particles being carried downward as the plates of the one frame descend. In Fig. 12 (not shown) the plates of only one frame have slits and are connected together in pairs, the plates of the other being individually mounted and having bulbous upper edges the thickness of which conforms to the lateral spacing between adjacent plates of the one frame.