声场流化床中超细颗粒聚团受力与尺寸  

Acting Forces and Agglomerate Sizes of Super Fine Particles in an Acoustic Fluidized Bed

作　　者：苏吉[1] 朱庆山[1] 

机构地区：[1]中国科学院过程工程研究所,北京100190

出　　处：《过程工程学报》2010年第3期431-437,共7页The Chinese Journal of Process Engineering

基　　金：国家重点基础研究发展规划(973)基金资助项目(编号:2007C13613502)

摘　　要：在内径40mm的流化床中,采用平均粒径为7.4μm的超细铁矿颗粒进行声场流态化实验.结果显示,聚团尺寸随声压级增大逐渐减小,在固定声压级的条件下存在最优声波频率,本实验为130Hz.由铁矿颗粒声场流态化中聚团受力分析提出聚团受力平衡模型,当促进聚团破碎的力和促进聚团形成的力相等时,计算出一定频率不同声压级下的聚团尺寸,在频率130Hz、声压120.5db下,根据模型计算得到的聚团直径为384μm,而通过最小流化速度计算值为367μm,二者较接近.Super fine iron ore particles （7.4 μm） were fluidized in a 40 mm i.d. fluidized bed with sound excitation. The results showed that the size of agglomerate was decreased with increasing the sound pressure level. At a given sound pressure level, there existed an optimal sound frequency of 130 Hz in this work. A force balance model was developed to predict the agglomerate size through analyzing the forces acting on the agglomerates based on the assumption that the agglomerate will reach a stable size when the detached forces and adherent forces acting on the agglomerate are equal. The agglomerate size is predicted to be 367 μm by the model at the sound pressure level of 120.5 db and the sound frequency of 130 Hz, which is in good agreement with the size of 384 μm calculated from the minimum fluidized velocity under the same condition.

关 键 词：声场流化床 聚团大小 聚团受力平衡模型 声压级 

分 类 号：TQ051[化学工程]