Multiple odd bell-shaped opening nozzle device for a fluidized bed jet mill

摘要

PROBLEM TO BE SOLVED: To improve the efficiency of a fluidization base layer jet mill and to reduce costs by nozzle design in the jet mill for crushing raw material particles.;SOLUTION: A plurality of nozzle devices for releasing the synthetic stream of a high speed fluid into a crushing chamber are set in the side wall of the mill to penetrate the wall. The raw material particles are received by the high speed fluid to be conveyed and introduced into the chamber to be made to collide with each other. Each high-speed stream is released from double-odd-bell-like openings 106 formed in each nozzle device to form the synthetic stream. A large amount of the high-speed fluid moving from the first end to the second end of each opening 106 is converged and accelerated in a convergence region 112, passes through a throat region 114, and is expanded and made a parallel flow linearly in the first expansion region 116 and rotationally in the second expansion region 118. Along the flow, the radius r1 and length s1 of the region 116 are determined to make dr1/ds1 a constant, and the radius r2 and length s2 of the region 118 are determined to make dr2/ds2 a non-linear function of s2.;COPYRIGHT: (C)2004,JPO