外环流气提式反应器液体局部动力学的实验研究和数值模拟

在外环流气提式气液反应器内,分别以空气和质量分数5%羧甲基纤维素（CMC）水溶液为气相和液相,对液相局部动力学进行了系统研究。应用电极示踪测试技术（ETM）测定了下降段液体速度;应用计算流体力学软件FLUENT 6.0对上升段的液体湍动能和湍动能耗散率进行了模拟计算。模拟结果表明：气体分布器对液体湍动能和湍动能耗散率有较大影响,液体湍动能和湍动能耗散率随表观气速的增大均增大,且液体湍动能呈现出较对称的波动模式。在低气速下,局部液体速率的模拟结果与实验数据吻合良好。

Experimental and Numerical Simulation for Liquid Phase Local Hydrodynamics in an External Loop Airlift Reactor

A gas-liquid external loop airlift reactor was employed to investigate the liquid phase local hydrodynamics using air and 5 % （mass）CMC water solution as gas and liquid phases, respectively. Liquid flow velocity in the down-comer was measured using the electrolyte tracer measurement （ETM） technique. Turbulent kinetic energy and turbu lent kinetic energy dissipation rate of liquid phase were systematically simulated using FLUENT 6.0 CFD code in the riser. The simulation results show that turbulent kinetic energy and turbulent kinetic energy dissipation rate are influenced by the gas distribu tor. It is also indicated that turbulent kinetic energy and turbulent kinetic energy dissi pation rate of liquid phase are both increased with increasing superficial gas velocity, and liquid phase turbulent kinetic energy profiles present from relative symmetry to fluctuate mode with increasing superficial gas velocity. The numerical simulating results of liquid velocities agree with the experimental data at low gas flow rate.