GB699386A - Classifier for material reduction mills - Google Patents

Abstract

699,386. Separating solid materials. WESTON, D. Oct. 3, 1951 [Aug. 1, 1951], No. 23065/51. Class 117 A classifier for the solid particles entrained by an airstream from a material reduction mill comprises two duct portions 18, 17 with longitudinal axes co-planar and intersecting at an angle between about 128 degrees and 94 degrees in a plane of intersection 30 at least 1.5 times the area of a plane of connection 26 to the first portion, a foraminous member 32 covering an opening in the base of the first portion on which fall particles above a certain size or weight which impinge on the wall of the second portion 17 and are brought to rest by it and means 19 for collecting particles which pass through the foraminous member. The particles not passing through the screen member 32 are returned to the reduction mill. The screen may be vibrated by a member 38. The portion 18 should have, for even flow, a length at least 2.4 times the mean diameter of the plane of connection 26 and its axis should intersect the wall of the portion 17 at an acute angle not less than 38 degrees. The portion 17 should have a length at least 1.5 times the mean diameter of the plane 30 of intersection. The air stream finally passes to a main products collector the air velocity. The outlet from the collector 19 is via an air lock 75. 'In a modification various classifier ducts are serially connected, of diameters increasing successively downstream, giving successive graded outputs from foraminous members at the bases of the ducts.