化工学报2016，Vol.67Issue(6)：2300-2307,8.DOI:10.11949/j.issn.0438-1157.20151664
气浮接触区气泡聚并行为的数值模拟
Numerical simulation of bubble coalescence behavior in contact zone of dissolved air flotation tank
摘要
Abstract
Bubble coalescence can make the increase of bubble size in the contact zone of the dissolved air flotation tank, which will finally influence the separation efficiency. Population balance model was employed to study bubble coalescence behavior in the contact zone. With this numerical method, the bubble coalescence mechanism and effect of mainstream and recycle flow rates on coalescence phenomenon were studied. At first, Schiller-Naumann, Grace and Tomiyama drag coefficient models were included in the simulation process, respectively. The results showed that the bubble sizes simulated with these three models were similar with good accordance with the experimental data. Schiller-Naumann was adopted in the following simulation as its computational cost was lower than Grace and Tomiyama model. By comparing the bubble size distribution with velocity profile, high velocity gradient was detected at the upstream and downstream flow transition region around the recycle flow inlet. The high velocity gradient was proved to be the key factor causing bubble coalescence. At last, the influence of mainstream and recycle flow rates on bubble size was investigated. Bubble size in the contact zone increased with the increase of recycle flow rate because the velocity gradient at upstream and downstream transition region increased, which can enhance the bubble coalescence. On the contrary, mainstream flow rate showed no effect on bubble size distribution in the contact zone.关键词
气浮/气泡/聚并/速度梯度/相群平衡模型/数值模拟/计算流体力学Key words
air flotation/bubble/coalescence/velocity gradient/population balance model/numerical simulation/computational fluid dynamics分类
化学化工引用本文复制引用
陈阿强,王振波,王晨,杨佳佳,金有海..气浮接触区气泡聚并行为的数值模拟[J].化工学报,2016,67(6):2300-2307,8.基金项目
中央高校基本科研业务费专项资金项目（14CX06097A）。@@@@supported by theFundamental Research Funds for the Central Universities (14CX06097A) （14CX06097A）
