GB934424A - Apparatus for classifying solids - Google Patents

Abstract

934,424. Centrifugal separators. POLYSIUS G.m.b.H. Feb. 8, 1961 [Feb. 15, 1960], No. 4746/61. Addition to 934,423. Class 23. Apparatus for classifying solid particles comprises a swirling chamber b in which the unclassified particles are mixed with and given a rotary motion by air supplied to the chamber through a tangential inlet c, an accelerator duct g and a diffuser h defined by the space between an outer conical casing i and an inner coaxial conical core k through which space the discharge from the chamber b passes in a spiral path and is separated at the outlet q of the diffuser into fine and coarse particles collected respectively in a funnel r opening into a pipe p and in a chamber m leading to a shoot n. The unclassified material is fed to the chamber b through a shoot a and an admission tube d having mixing slots e or deflectors f. The core k is part of a double-coned core mounted in a stationary casing and carried by a hollow spindle t1 slidable on a spindle t2 attached to the funnel r which is slidable in the pipe p. The core and the funnel r can each be raised or lowered by means of hand wheels u1 and u2 respectively to control the degree of classification which may also be varied by admitting external air through a circumferential slot s formed in the casing wall i and controlled by a ring-shaped valve element having adjusting screws v. The finer particles issuing from the pipe p may be separated from the entraining air in a separate separator (not shown). In a modification, Fig. 2 (not shown), the funnel r is modified to form a cyclone separator from which the fine particles are discharged through the pipe p and the air is exhausted through a central pipe extending upwards through the diffuser and the swirling chamber b.