AIR CLASSIFIER

PURPOSE:To improve the precision of classification by forming a classification chamber on the periphery of a rotary vane below a material inlet, providing a diffusion plate opposed to the material inlet to the rotary vane, and fixing a collision plate arranged at a distance from the periphery of the diffusion plate to the diffusion plate. CONSTITUTION:The rotary vane 18 is provided below the material inlet 14, and the classification chamber 24 is formed on the periphery of the rotary vane 18. An air inlet 12 is allowed to communicate with a fine powder discharge port 13 through the classification chamber 24. The diffusion plate 21 opposed to the material inlet 14 is provided to the rotary vane 18, the collision plate 23 is arranged at a distance from the periphery of the diffusion plate 21, and the collision plate 23 is fixed to the diffusion plate 21. As a result, the collison plate 23 and diffusion plate 21 are rotated at the same angular velocity. Consequently, even if particulate matter collides with the collision plate, the particulate matter is sufficiently diffused, dropped into the classification chamber, and joined to a classifying air current. Accordingly, the particulate matter dropped into the classification chamber is immediately and sufficiently classified, and the precision of classification can be remarkably improved.