GB390456A - Centrifugal classifying apparatus - Google Patents

Abstract

390,456. Centrifugal classifiers. INTERNATIONAL PRECIPITATION CO., 1016, West 9th Street, Los Angeles, and LISSMAN, M. A., 339, North Rosemead Avenue, Temple, both in California, U.S.A. Nov. 10, 1932, No. 31843. [Class 23.] A centrifugal classifier has a cylindrical part 33, which acts as a cyclone separator, to which the material laden gas is supplied through an annular passage 29 between the external casing 1 and the deflector 23. A return tube 24 is arranged inside the deflector, and a fan 4 is arranged above it. The fan is rotated by a motor 15 and carries on its upper face a distributing disc 3. The fan maintains a circulation of air down the annular passage 29, under the edge of the deflector 23 to the separator 33 ; the continued whirling of the air causes it to travel downwards near the periphery of the chamber and then upwards near the axis to the return tube and the fan. The solids to be classified pass from the hopper 5 to the chamber 7 from which they drop on to the distributing disc 3. They are thrown from this disc to the casing 1, and the impact dislodges the fine material from the coarser particles. These latter particles drop down the wall of the casing 1, and fall through slots in the flanges 35 of the deflector 36. They then pass between the walls 1, 33 to the funnel 50 and collector 52. The fine material is carried by the circulating air to the cyclone separator where the material is separated to drop to the funnel 53 and the collector 55. A funnel 56 may be placed inside the separator, and a fan 58 connected to a pipe 59 under the funnel, for the purpose of withdrawing some air to assist in the maintenance of the flow and thus facilitate separation. The deflector 36 can be raised or lowered by means of screws 39 ; access to the screws is given by openings in the casing normally closed by doors 42<1>. The deflector 23 is of conical form so that the space between it and the casing 1 diminishes downwardly. In a modification air is supplied to the annular passage 29 through a volute, and the clean gas discharges from the pipe 24 through another volute. The volutes are arranged in the reverse manner so that the gas whirls continuously in the same direction, and the walls 24, 33 may have adjustable sleeves at their ends.