Air classifier

摘要

An air classifier comprises a casing formed of a generally hollow cylindrical vertical casing body and an inverted conical hopper fixed to the lower wall of the casing body. A fine product outlet duct is provided at the center of the upper wall of the casing body. An air-powdered material inlet duct and a secondary air inlet duct are set in the diametrically opposite positions of the vertical wall of the casing body to project tangentially outward. A vertical rotary shaft extends through the central portion of the casing body. A rotary disc member for concurrently carrying out the dispersion and classification of a powder raw material is fitted to the lower end of the rotary shaft at a boundary between the casing body and hopper. A cage-shaped assembly of guide vanes is provided in the casing body to conduct a mixture of air and powdered material into the casing body. The air classifier of this invention constructed as described above can precisely classify by itself a large amount of powder material as a classifier for swept-air from a mill.