Classification are based on the effects of centrifugal force, gravity, inertial force, etc., of different sizes powders in the medium (usually air) to form different trajectories, so as to realize the separation of different sizes powders.
Material would go from the bottom part of air classifier up to the classifying chamber by the air flow from suction fan. The classifier wheel with high-speed rotation would create a strong centrifugal force to separate coarse and fine powder. Qualified fine powder would go through the wheel vane then into the cyclone or bag filter, while coarse entraining fine powder would lose its speed and fall down along the wall of chamber to the inlet of secondary air. The secondary air flow would disperse it further and separate coarse and fine powder. Fine powder would go up to the classifying chamber for further classifying, while coarse powder would fall down and will be discharged from the bottom outlet.