FINE-PARTICLE SEPARATION BY REVISED TYPE AIR-CYCLONE CLASSIFIER

Experimental and theoretical studies were conducted on the separation of submicron powder by use of a revised type of cyclone. The cyclone has a movable inlet guide plate at the inlet section, and 50% cut size is controlled from 0.45 to 0.75 mum by changing the inlet clearance of the guide plate. But the 50% cut size increases again under the condition of very narrow inlet clearance of the guide plate, because the radial velocity of particles decreases and fluid turbulence increases in the case of very narrow inlet clearance. The 50% cut size decreases to about 0.4 mum by use of both the inlet guide plate and the blowdown method. The partial separation efficiency with a spiral-inlet cyclone is higher than a cyclone with tangential inlet, and the 50% cut size decreases with a highly polished inside wall surface.