PURPOSE: To adjust the crushing capacity in an air classifier, wherein a raw material inlet and a pin mill are provided in a dispersion chamber on the upper face side of a classifying rotor and the dispersion chamber is allowed to communicate with a classification chamber, by furnishing a detachable pin of the pin mill.
CONSTITUTION: A supporting ring R provided with a desired detachable pin 9 is selected and fixed to a dispersion chamber 12, the switching valve V of a raw material supply means 7 is opened to close an outer feed port 7b and to open an inner feed port 7a. Classifying air SA is sent through a guide vane 4 to form a free spiral flow in a classification chamber 11, a rotor shaft 13 is rotated to rotate the classifying block 3, and hence a forced spiral flow is formed and flows into an exhaust duct 6 as an ascending air current. Under such conditions, fly ash F is charged into the means 7, discharged into the dispersion chamber 12, crushed by a pin mill M, dispersed, collided with the inner wall 5 and dropped into the classification chamber 11. The fly ash F is classified into a fine powder S and a coarse powder L by the balancing action between the centrifugal force and air resistance.
KAMAKURA HIROKI
TAMAE TAKAMIKI
FUJII SATORU
CHICHIBU ONODA CEMENT CORP