PURPOSE: To expand the diameter of a feeding route to improve crushing efficiency by making a feeding port in the center part of a top board of a crushing chamber and fitting an upper reinforcement to the peripheral edge part of the feeding port and also fitting a lower reinforcement adjacent to the upper reinforcement to the upper end of a feeding port arranged in the center part of an upper disc of a rotor.

CONSTITUTION: In a centrifugal crusher for crushing a raw material such as a mineral, the material to be crushed is discharged from a peripheral surface opening of a rotor 2 horizontally rotating installed in the center part of a crushing chamber 11 toward an impact member provided on the peripheral edge part of the crushing chamber 11 and is crushed. In this case, feeding ports are arranged in the center part of a top board 13 of the crushing chamber 11 and in the center part of an upper disc of the rotor 2 respecitively so that their center axes may be arranged in a straight line. In the arranged feeding ports, an annular upper reinforcement 5 and a tubular reinforcement 6 are fitted respectively, and the upper end of the lower reinforcement 6 is made adjacent to the upper reinforcement 5. The diameter of a feeding route of the upper reinforcement 5 is formed a little smaller than that of the lower reinforcement 6.