搅拌槽内非牛顿流体的微观混合特性  

Micromixing characteristics of non-Newtonian fluid in a stirred tank

作　　者：丛海峰[1] 高正明[1] Atibeni R A 闵健[1] 

机构地区：[1]北京化工大学化学工程学院,北京100029

出　　处：《合成橡胶工业》2006年第1期14-17,共4页China Synthetic Rubber Industry

基　　金：国家自然科学基金资助项目(29976002)。

摘　　要：在直径为0．476m的搅拌槽内，分别选用三窄叶翼型搅拌桨和标准六直叶涡轮搅拌桨，采用羟乙基纤维素（HEC）水溶液非牛顿流体作为工作体系，以改进的硫酸铜沉降反应与氯乙酸乙酯水解反应的平行竞争反应作为研究微观混合的反应工作体系，在质量分数为0．1％-0．5％的HEC水溶液中，排除硫酸铜副反应的影响，利用铜离子质量浓度与可见光吸光度的线性关系，考察了进料时间、搅拌转速、溶液黏度、流体的非牛顿性以及搅拌桨类型等因素对副产物收率（XQ）的影响规律。结果表明，当进料时间超过临界进料时间3500s后，XQ不再改变；随着搅拌转速的增加，XQ减小，但其减小的趋势逐渐变缓；在相同转速下，XQ随着流体黏度的增加而增加，但增加的趋势有所减缓；对于黏性流体不能仅仅采用雷诺数作为放大准则；在相同的能量耗散速率及桨叶区进料的情况下，Damkohler准数较大的标准六直叶涡轮搅拌桨的XQ较小。The improved parallel competive reactions, the precipitation reaction of CuSO4 and hydrolysis of ethyl chloroacetate, were used as reaction system to investigate the micromixing in non-Newto- nian fluid of mass fraction of water solution of hydroxyethyl cellulose （HEC） 0. 1% - 0. 5% in a stirred tank of diameter 0. 476 m with a three narrow blade hydrofoil agitator blade and standard six vertical blade turbine agitator blade. The effects of feed time, speed of agitator, viscosity of solution, nonNewtonian factors and types of agitator blade on the yield of by-product （XQ） were studied based on the linear relationship between mass concentration of copper ion and absorbency of visible light without consideration of effect of side reaction of CuSO4.The results showed that XQ did not changed when feed time was more than critical feed time 3 500 s. XQ decreased as the speed of agitator increased, but the trend became weaker. XQ increased greatly as the viscosity of water solution of HEC increased at the same speed of agitator, but the trend became weaker. The Reynolds number was not the suitable scaling-up rule for the viscous liquid. Under the same speed of dissipation power and feeding in the agitator blade region, XQ for standard six vertical blade turbine aqitator blade with higher Damkohler number was smaller.

关 键 词：微观混合 非牛顿流体 搅拌槽 平行竞争反应 

分 类 号：TQ027.2[化学工程]