(239a) Fine Particle Classification with Revised Cyclone

Experimental and numerical studies have been conducted about the cut size control with revised dry cyclone. New type of dry cyclone with the movable apex cone which is covered with special shaped ring indicated cut size movement from 2 to 40μm.. By use of the apex cone at the inlet of dust box, it is possible to decrease the fluid velocity component in the dust box and to reduce the re-entrainment of particles from the dust box. The cut size indicates the minimum value for the specific height of the apex cone. The optimum apex cone height changes to the lower position as the cyclone inlet velocity increases. Classification performance of revised cyclone with the use of additional fluid in a upper cylindrical part were also examined. By selecting a special part of additional flow position, it is possible to reduce the cut size with the increase of additional flow rate. Three dimensional numerical simulation were also conducted and compared with the experimental data.