导流筒结构对气升式环流反应器内气液两相流动的影响

使用欧拉-欧拉两流体模型研究了导流筒结构对气升式环流反应器内气液两相流动的影响。对物理模型进行了网格独立性的考察,使用Chisti关系式验证计算流体力学数值模型的可靠性,并在此基础上预测环己烷氧化反应器内导流筒直径、导流筒在反应器内的高度以及导流筒喇叭口的开度对反应器内气液两相流动的影响。模拟结果表明,导流筒上部增加喇叭口可有效提高反应器的气液分离能力,喇叭口直径增大,气液分离效果增强;导流筒直径增大,液相循环量增大,液相混合效果增强;随导流筒在反应器内的位置升高,液相表观速度和液相循环量呈增加的趋势并趋于稳定,而气含率则变化不大。

Effect of Draft- Tube Structure on Gas -Liquid Flow in Airlift Loop Reactor

Eulerian-Eulerian two fluid model was applied to investigate effect of draft-tube structure on(gas-)liquid flow in airlift loop reactor.Grid-independence was studied and result obtained by simulation was validated by using Chisti's correlation.Effects of draft-tube structure,including draft-tube diameter,draft-tube positional height in reactor and draft-tube horn mouth diameter,on gas-liquid flow characteristic were studied by computational fluid dynamics(CFD)digital simulation.Distribution of liquid velocity and gas holdup in reactor were investigated and results showed that installation of draft-tube horn mouth could improve ability of reactor in gas liquid separation and liquid circulation.Efficiency of gas-liquid separation was enhanced with enlarging horn mouth diameter,and so liquid mixing efficiency increased.Liquid circulation speeded up firstly and then kept constant when draft-tube positional height lifted.Situation of draft-tube in reactor did not apparently affect gas hold-up.