气流预分散对涡流空气分级机分级性能的影响  

Effect of airflow pre-dispersion on classification performance in a turbo air classifier

作　　者：郭丽杰[1] 刘家祥[1] 王京刚[2] 陈贯坤[1] 

机构地区：[1]北京化工大学材料科学与工程学院,北京100029 [2]北京化工大学化学工程学院,北京100029

出　　处：《化学工程》2007年第3期51-54,74,共5页Chemical Engineering(China)

基　　金：国家自然科学基金资助项目(50474035)

摘　　要：在物料进入涡流空气分级机前采用了气流预分散装置,使物料悬浮分散并输送到分级机中。以滑石粉和石灰石粉料为原料进行分级实验,研究不同条件下气流预分散对分级性能的影响。采用激光多普勒测速仪对分级机内环形区流场进行速度测定,分析预分散气流对流场的影响。结果表明,当预分散气速大于1.1 m/s时,细粉产率、牛顿分级效率和切割粒径随预分散气速的增大而增加;在不同的系统进口风速条件下,物料预分散后,细粉产率、牛顿分级效率增加;平均粒径小的石灰石粉料其中含有的超细颗粒(<4μm)不易实现气流预分散,预分散气流可以明显地减小对分级不利的轴向速度。The airflow pre-dispersion equipment was installed in a turbo air classifier before the raw materials were classified. Raw materials were suspended to disperse and conveyed to classifier by pressured airflow. The classification tests of talc and limestone powder were made and the effect of airflow pre-dispersion on classification performance was investigated under different conditions. Velocity measurement of the annular region in a turbo air classifier was performed by Laser Doppler Velocimeter （LDV）. The results show that output percentage and Newton classification efficiency of fine powder are increased with the increase of dispersion air velocity and cut size becomes bigger when the pre-disperse air velocity is larger than 1.1 m/s. Classification performance is improved after raw materials are pre-dispersed under the different system inlet air velocity conditions. The superfine particles （ 〈4 μm） in the limestone powder of the small mean diameter are not easy to be dispersed. The pre-dispersion airflow can decrease the axial velocity drastically which is detrimental to classification.

关 键 词：涡流空气分级机 气流预分散 分级性能 

分 类 号：TQ051.8[化学工程]