气升式环流反应器气液两相流动冷模实验

Cold Model Experiment on Gas-Liquid Two-Phase Flow in an Airlift Loop Reactor

运用粒子图像测速仪(PIV)技术研究了扁平气升式环流反应器内液相流动特性,测得了反应器内各个区域液相速度分布、流线分布。认为反应器上升段表观气速对液相水平速度和垂直速度均有影响,其中对液相垂直速度的影响更大:表观气速增大,液相最大垂直速度一般增大,但这一变化规律并不是单调的;PIV对折流区的观测反映了该区域流场在气相通入后的最初25 s内的变化历程,流场发展的快慢与进气口的气速有关,气速越大,流场发展得越快。研究结果为认识该类反应器内的流动混合特性及进行该类反应器的设计、优化提供了参考。

Fluid dynamics in a shallow airlift loop reactor was investigated using particle image velocimetry （PIV）. Distribution of detailed flow parameters such as liquid velocity and stream function were measured by this method. Superficial gas velocity takes effect on both liquid horizontal velocity and liquid vertical velocity. The maximum liquid vertical velocity increases with the increasing of superficial gas velocity, but this variation trend is not monotonous. Variation course of liquid velocity in the baffling region shows that the developing speed of the fluid flow increases with the increasing of superficial gas velocity also. The results are helpful to understand the fluid flow and mixing effect in the reactor and also be beneficial to the design and optimization of such kind of reactors.