POWDER CLASSIFICATION APPARATUS

PROBLEM TO BE SOLVED: To provide a powder classification apparatus which classifies powder with a size of a few μms or less or a size of a submicron with high accuracy using a grinding or dispersing device and a cyclone-type separation device. SOLUTION: The powder classification apparatus includes a cyclone which comprises a cylindrical part and an inverted truncated cone part extended below the cylindrical part and forms a whirling flow along the inner circumferential wall of the cylindrical part and the inverted truncated cone part and whirls coarse powder and falls it, a disclike whirling flow forming part which is arranged above the cyclone and has a diameter larger than that of the cylindrical part of the cyclone, a powder supply part arranged at the outer circumferential part of the disclike whirling flow forming part to which the powder is transferred by air flow from a tangential direction and is supplied, a ringlike edge arranged at least at one of the upper and lower surfaces inside the disclike whirling flow forming part, a discharging part which is arranged above the cyclone and discharges air flow containing fine powder, and a recovery part of the coarse powder which is arranged below the cyclone. COPYRIGHT: (C)2009,JPO&INPIT