Abstract: The classify-impact mill possesses the advantage of high output. It is also widely used in crushing industry. However,the study of classify- impact mill is still insufficient. The grinding experiment of LNI-66A classify-impact mill was finished in this paper. The results showed that its production was higher than 4 beaters or 8 beaters when 2 beaters were used in classify-impact mill. As for the height of beaters,the production was higher than 10mm,20mm,40mm and even 50mm when the height of beaters was 30mm. Ansys Workbench 15.0 was used for numerical simulation of crushing cavity in this study. The distribution of the crushing cavity flow field presented by its velocity field and pressure field,and the influence of the flow field in grinding area caused by the parameters of beaters were discussed in this paper. Simulation results showed that the radial velocity of grinding area changed little while the pressure increased with the increase of the number of beaters. The crushing efficiency and powder production decreased on account of the increase of the number of beaters. The velocity of rising air near beaters and the crushing areas of beaters would be affected by the height of beaters. The velocity of rising air near beaters could reduce the crushing efficiency, while the crushing areas of beaters could increase the crushing efficiency,showing that there was a better choice between the two aspects. As a result,the height of beaters cannot be higher or lower and there was a better value in it.

Key words: classify-impact mill, the number of beaters, the height of beaters, CFD numerical simulation

摘要： 分级式冲击磨具有产量大、应用广等优点，但目前对分级式冲击磨的研究仍不够充分。本文利用LNI-66A型分级式冲击磨进行了粉碎实验，结果表明，锤头数量为2个时，粉体产量比锤头数量为4个和8个时高；锤头高度为30mm时，粉体产量比锤头高度为10mm、20mm、40mm、50mm时高。利用Ansys Workbench 15.0，对粉碎腔内的流场进行了数值模拟，得出了压力场和速度场的分布情况，探讨了锤头参数对磨盘粉碎区域流场的影响。模拟结果表明，随着锤头数量的增加，粉碎区域流场径向速度变化不大，而压力会随之增加，这将使得粉碎效率降低，粉体产量下降。锤头高度对锤头附近气流上升速度和锤头打击面积都有影响，前者会降低粉碎效率，后者会提高粉碎效率，在两者间应有一个择中的取值。因此，锤头高度并不是越高越好，是有一个较优取值的。

关键词: 分级式冲击磨, 锤头数量, 锤头高度, CFD数值模拟