CIESC Journal

• 化工学报 • 上一篇    下一篇

快速流态化气固两相间的动量交换

白丁荣,金涌,俞芷青   

  1. 清华大学化工系,清华大学化工系,清华大学化工系 北京 ,北京 ,北京
  • 出版日期:1991-10-25 发布日期:1991-10-25

Momentum Exchange Between Gas and Solids in Fast Fluidized Bed

Bai Dingrong, Jin Yong and Yu Zhiqing (Department of Chemical Engineering, Tsinghua University, Beijing)   

  • Online:1991-10-25 Published:1991-10-25

摘要: 本文根据一维定常态流动模型,对快速流化床内气固两相间的相互作用及其机理进行了研究.结果表明,在快速流态化条件下,颗粒总是趋于聚集,以减小气固两相间的相互作用力,从而使曳力系数c_D小于单颗粒标准曳力系数c_(DS)(c_D/c_(DS)<1.0).c_D/c_(DS)不仅与(?)有关,而且受气固流动状况以及颗粒物性、床层直径等因素的影响.通过对大量数据的分析,得到预测曳力系数的经验关联式(平均相对偏差小于5%)c_D/c_(DS)=1.685(?)~(0.253)(Re_r/Re_t)~(-1.213)(d_p/D)~(0.105)

Abstract: The mechanism of interaction between gas and particles have been investigated with an one-dimensional gas-solids flow model for fast fluidized bed. It was found that the aggregation of particles (i. e. shielding effect) weakened the interaction between gas and solids, thus the drag coefficient of aggregated particles in fast fluidization was less than that of individual particle in an infinite field, e. g., CD/CDS<1.0. The value of CD/CDS not only decreased with decreasing bed voidage, but also is a function of gas-solids flow pattern, particle properties and bed diameter. The empirical correlation to predict the particle drag coefficient in fast fluidization regime is as follows: