搅拌器内两相流动及混合过程的数值分析  

Numerical analysis of two-phase flow and mixing process in stirred tank

作　　者：黄思[1] 郑茂溪[1] 王宏君[1] 

机构地区：[1]华南理工大学工业装备与控制工程学院,广东广州510640

出　　处：《合成橡胶工业》2008年第3期174-178,共5页China Synthetic Rubber Industry

基　　金：华南理工大学回国人员科研启动基金资助项目(K7050040)

摘　　要：以油和水2种液体作为模拟实例,搅拌器采用宽桨和窄桨2种叶轮的组合方式,应用计算流体力学技术对搅拌器中两相介质的混合过程进行模拟分析。结果表明,搅拌的开始阶段,两相流体无论是流场分布或是流动范围均有较大的区别,随着搅拌时间的延长,叶轮抽吸结果使搅拌轴中心产生低压区;重相液体因叶轮离心力的作用一般集中在容器边壁;轻相液体则在上层叶轮的作用下首先向搅拌轴中心聚集,然后沿着搅拌轴向下移动,到达容器底部后在下层叶轮的作用下扩散到搅拌槽四周,最后两相流体的流场分布、流动范围逐渐趋近一致,达到均匀状态;下层叶轮的转矩及轴功率是上层叶轮的2倍以上,选取高效的下层叶轮对于提高搅拌装置的效率十分重要。By means of computational fluid dynamics technique, a liquid-liquid two-phase turbulent flow and the mixing process in a stirred tank was studied numerically. Water and oil were selected as the liquids in the work. The stirred tank was equipped with a central shaft connecting to two agitators： one wide-blade-impeller and one narrowblade-impeller. Some significant nature in the process was found and outlined. Both flow field distribution and flow scope in each phase were considerably different during the startup stage. With the progress of mixing, a lower pressure zone in the central area of shaft took place due to the rotation of agitators. Heavier fluid was generally pushed out and cumulated on the wall of the tank due to the centrifugal force. The lighter liquid concentrated on the shaft first, moved down to the lower part of the tank along the shaft and then spreaded all around. While flow entered quasi-steady state, both phases were approximately well-distributed and finally tended to be homogenous. Both the torque and shaft power consumed by impeller at lower position was approximately two times of that consumed by the upper impeller. It was important to select a high-efficiency impeller at the lower position for improving performance of a stirred tank.

关 键 词：搅拌器 两相流动 混合过程 数值模拟 

分 类 号：TQ019[化学工程]