旋风分离器排气管最佳插入深度的实验与分析

Experiment and analysis of vortex finder optimum length in cyclone separator

采用实验方法考察物料特性、入口气速、排气管直径、入口截面积4种因素对排气管最佳插入深度的影响。实验结果表明,排气管的最佳插入深度主要受粉料中位粒径和粒径分布的影响,中位粒径越小,包含的小粒径颗粒越多,最佳插入深度越大,而与其他3项参数无关。另外,插入深度在最佳位置附近变化时,效率波动不大,远离最佳位置后,效率大幅下降,并且在大排气管直径,大入口条件下,效率对插入深度更为敏感。短路流和内旋流二次分离的协同作用是形成以上现象的主要原因。

Cold experiments were carried out to study the effects of powder properties including medium diameter of particle and size distribution of powder, inlet velocity and structure parameters including the diameter of vortex finder and the area of inlet on the separation efficiency. The results showed that vortex finder optimum length was mainly affected by medium diameter of particle and granulometric distribution of powder. The smaller the medium diameter of particle was, the more the small particle were, the longer the vortex finder optimum length was. Instead, other three parameters affected the vortex finder optimum length little. Besides, when the vortex finder length came close to best value, the efficiency only decreased a little. But when the vortex finder length was far away from the best value, the efficiency would drop dramatically. The efficiency of cyclone was more sensitive with big inlet area or diameter of vortex finder. The formation of above phenomenon was attributed to a combination of short circuit flow and secondary separation of inner swirl upward flow.