Abstract: Grading ring spacing size is one of the important factors affecting classification performance of a classifier.Models of vertical mill classifier with different grading ring spacing sizes were built, and flow field characteristics of different grading ring spacing sizes in vertical mill classifier SMG5500 were studied with the Fluent software.The best grading ring spacing size was obtained by making a comparative analysis of the influence on velocity field, stress field and classification efficiency at different spacing sizes.A test on the classifier was made.Simulated result showed that if grading ring spacing size was too small, most coarse particles larger than 80 μm could enter the cage, resulting in much coarser size particles in the product.If grading ring spacing size was too large, most coarse particles less than 80 μm could not enter the cage, increasing the classifier cycle load and extremely limiting classification efficiency.The vertical mill classifier SMG5500 showed optimal classification performance if grading ring spacing size was around 110 mm.

Key words: grading ring spacing, vertical mill classifier, two-phase flow

摘要： 分级环间距大小是影响选粉机分级性能指标的重要因素之一。通过构建不同分级环间距的立磨选粉机模型,采用Fluent软件对SMG5500型立磨选粉机不同分级环间距下的流场特性进行研究,对比分析间距大小对速度场、压力场和分级效率的影响规律,得出最优的分级环间距,并对整机进行实验验证。数值模拟结果表明:当分级环间距过小时,大部分大于80 μm的粗颗粒都能进入转笼,使产品极易出现跑粗现象;当分级环间距过大时,大部分小于80 μm的颗粒不能进入转笼,这使得选粉机的循环负荷加大,选粉效率受到了极大的限制;当分级环间距为110 mm左右时,SMG5500型立磨选粉机的分级性能最优。

关键词: 分级环间距, 立磨选粉机, 两相流