涡流分级机蜗壳内水平隔板对其流场的影响

为了探究蜗壳结构对涡流空气分级机流场特性的影响,文中利用Fluent软件对蜗壳内增加不同数目水平隔板的涡流空气分级机流场进行数值模拟。研究表明:蜗壳内水平隔板数目对流场速度以及环形区湍流耗散率有不同影响,存在临界隔板数使流场轴向速度分布均匀,在本文条件下的临界隔板数为3;在蜗壳中增加水平隔板可以对转笼外柱面处切向速度产生不同影响,在文中条件下增加1—3层水平隔板可以在一定程度上减小转笼切向速度与气流切向速度的差值,从而改善转笼叶片间的惯性反漩涡;随着隔板数的增加,湍流耗散率得到显著提高,物料分散性变好;涡流空气分级机的结构设计中应当考虑水平隔板对分级流场的影响。

Effect of volute with horizontal plates on flow fields in turbo air classifiers

The numerical simulation of flow field was performed with Fluent software in order to research the effect of volute with different number of horizontal plates on flow fields of turbo air classifiers.The results show that there are different effects on the axial velocity of flow field and tangential velocity on the front-surface of rotor cage blades when a different number of horizontal plates are added.The existing critical value(3 horizontal plates) makes the lowest axial velocity with the most uniform distribution.The difference between the rotor cages and flow field in the value of tangential velocity can be reduced to a certain extent when 1-3 layer horizontal plates are added under the aforesaid condition.The turbulent dissipation rate is improved greatly with the increase of horizontal plates,resulting in a narrow distribution area of separation size and an excellent classification precision.All the effects of horizontal plates on the flow field should be taken into account in the structure design of turbo air classifiers.