偏心搅拌的流动、悬浮和混合特性  

Flow, Suspension and Mixing Characteristics of Eccentric Stirring

作　　者：毕华飞 周坤[1] 黄雄斌[1] BI Hua-fei ZHOU Kun HUANG Xiong-bin(College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China)

机构地区：[1]北京化工大学化学工程学院,北京100029

出　　处：《过程工程学报》2017年第1期52-57,共6页The Chinese Journal of Process Engineering

基　　金：国家自然科学基金资助项目(编号:21376016;21506005)

摘　　要：在直径476 mm的平底圆柱形搅拌槽内,研究了CBY型搅拌桨偏心搅拌的漩涡运动轨迹、漩涡深度规律、上浮颗粒均匀下拉转速、混合时间等特性与偏心率的关系.结果表明,偏心率约为0.45时,漩涡中心分别随偏心率增加作线性与弧线运动,运动轨迹满足一定规律.漩涡深度受偏心率影响远大于转速与物料粘度.偏心率对液位下降率的影响程度是转速的1.9倍,是物料粘度的4.4倍.漩涡深度随偏心率增大而减小,并满足一定线性规律.直径4 mm的聚氯乙烯颗粒均匀下拉转速随偏心率增加先减小后增大,最低值时偏心率为0.4~0.5.液位由0.6T上升到1.0T(T为搅拌槽内径),最佳偏心率转速增加了20.3%,搅拌功耗增大.加装单一挡板改变槽内液体流场,漩涡消失,相同加料位置全挡板混合时间较无挡板时缩短66.9%,混合效果明显增强.The relationship of eccentricity ratio with the vortex motion trajectory, the depth of the vortex, the uniform drop-down velocity and the mixing time of CBY impeller were investigated. The experiments were carried out in a flat bottomed cylindrical stirred tank with the diameter 476 mm. The results showed that vortex center do linear motion and arc motion when eccentricity ratio before and after 0.45. The trajectory of the vortex center satisfies a certain law. The depth of the vortex is affected by the eccentricity ratio much more than rotational speed and material viscosity. In this experimental condition, the effect of eccentricity is 1.9 times of the speed to the drop rate of liquid level and 4.4 times of material viscosity. Vortex depth reduces as the eccentricity ratio increases. It satisfies certain linear rule. The uniform drop-down velocity of polyvinyl chloride with the diameter 4 mm increases first and then decreases as the eccentricity ratio increases. The eccentricity ratio at minimum inflection point is 0.4~0.5. The best eccentricity speed increased by 20.3% when the liquid level rises from 1.0T to 0.6T（T is diameter of stirred tank）. Stirring power consumption is increased. Adding a single baffle will change the liquid flow field in the tank and make the vortex disappear. But in the same adding material position, the mixing time of full baffle is shorter than that no baffle 66.9%. The mixing effect was obviously enhanced.

关 键 词：偏心搅拌 漩涡运动轨迹 漩涡深度 聚氯乙烯 混合时间 

分 类 号：TQ027.3[化学工程]