CIESC Journal

• 化工学报 • 上一篇    下一篇

搅拌混合中的循环与剪切

蔡志武,戴干策   

  1. 华东理工大学联合化学反应工程研究所!上海200237,华东理工大学联合化学反应工程研究所!上海200237
  • 出版日期:1996-04-25 发布日期:1996-04-25

CIRCULATION AND SHEAR IN STIRRING AND MIXING

Cai Zhiwu;Dai Gance(UNILAB Research Centre of Chemical Reaction Engineering,East China University of Science and Technology,Shanghai200237)   

  • Online:1996-04-25 Published:1996-04-25

摘要: 搅拌混合中的循环与剪切被定量化,搅拌功率分解为P=Q∑S_k,分解后的循环流量和总剪切强度,以及剪切强度在空间的分布应匹配.混合对偶合反应过程影响的实验结果表明,循环/剪切比适中的搅拌桨能较好地满足偶合反应工艺的需要,其分隔指数最小.用修正的拉格朗日法进行过程模拟,结果表明团块的循环经历影响其局部分隔指数,增大单位体积功耗、循环/剪切比以及循环区与桨叶区的能耗分配比能降低偶合反应的分隔指数.

Abstract: Circulation and shear in stirring and mixing are quantitatively defined.Stirring power can be resolved as P = QZSk. Circulation rate and total shear intensity,and space distribution of energy dissipation rate should be matched.It is shown by experiments about the influence of mixing on coupling reaction that the impeller with of a medium circulation to shear ratio well matches the requirement of coupling reaction and its segregation index is minimum.The process is simulated by the modified Lagrange method.It is shown that the circulation experience of an aggregate influences the local segregation index,and the segregation index of coupling reaction can be reduced by enlarging the power dissipation per volume,the circulation to shear ratio,and the ratio of energy dissipation in the circulation zone and impeller zone.

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