GB1195088A - Method and Apparatus for Separating a Coarse Fraction from a Pneumatically Conveyed Flow of Particulate Material. - Google Patents

Abstract

1,195,088. Centrifugal separators. MIAG MUHLENBAU UND INDUSTRIE G.m.b.H. 13 Oct., 1967 [22 Oct., 1966], No. 46766/67. Heading B2P. Pneumatically conveyed particulate material is classified into a coarse and a fine fraction by guiding the material by means of the conveying air against a screening surface at an acute angle, the material which does not pass through the screen being removed from the screen surface and reconveyed thereagainst at an acute angle, the conveying air flowing through the screening surface and entraining with it the fine particles, and the coarse particles being intercepted by the screening surface and discharged therefrom. A cylindrical screen 2 and a rotor 3 halving skewed impellers are mounted in a pressuretight casing 1. The rotor is driven through vee belting 8 by a motor 6. Below the screen 2 are a funnel 9 with a sight glass 10 and a bucket wheel air-lock 11. The air flow carrying the material to be classified enters the interior of the screen tangentially as at 12. The air and the light particles after passing through the screen are sucked via a tangential outlet as at 13 while the coarse particles drop into the lock 11. The impellers of the rotor 3 maintain the helical flow of the air and particles within the screen and prevent clogging of the screen by causing the formation of eddies which either force the fine material through the screen or entrain them upwards. The skewed orientation of the impellers is also responsible for ensuring that the material impinges at a greater acute angle on to the screen than if the impellers were disposed radially.