偏心搅拌反应器内的液相混合行为

Liquid mixing in eccentric stirred tank

利用先进的无干扰流场测试手段——平面激光诱导荧光技术(PLIF),对斜叶桨搅拌反应器内的液相混合过程进行高精度定量可视化。对比了中心搅拌和3种不同偏心率下的偏心搅拌混合行为,引入参数混合均匀度和均匀混合时间定量描述测量平面的示踪剂浓度分布。研究发现,偏心搅拌过程由于破坏了流场的对称性,比中心搅拌能更快达到均匀混合。反应器内局部混合存在差异,偏心搅拌中不同监测点达到均匀混合时间差异较小,体现了偏心搅拌在液相混合中的优势。

The liquid mixing in a pitched blade stirred tank was studied by the non-intrusive planar laser induced fluorescence technique.The mixing behavior in the centric and eccentric stirring operations was evaluated with the parameters such as the uniformity index and the 95% mixing time calculated based on the measured tracer concentration distribution.The results show that the eccentric operation exhibits better mixing performance than the centric operation,owing to its asymmetrical flow.The mixing time is a local variable,depending on the monitoring point,but the variation in the mixing time is small in the eccentric stirred tank.