Fine Particle Separation by Revised Type Air-Cyclone Classifier [Translated]†

Experimental and theoretical studies were conducted on the separation of submicron powder using 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 μm by changing the inlet clearance of the guide plate. But the 50% cut size increases again with a very narrow inlet clearance of the guide plate, because the radial velocity of particles decreases and fluid turbulence increases under such condition. The 50% cut size decreases to about 0.4 μm when both the inlet guide plate and the blowdown method are used. 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. † This report was originally printed in KAGAKU KOGAKU RONBUNSHU, 19(3), 476-482 (1993) in Japanese, before being translated into English by KONA Editorial Committee with the permission of the editorial committee of the Soc. Chemical Engineers, Japan.