气升式环流反应器在不同体系下的循环液速和局部气含率

在气升式环流反应器中,分别研究了空气—水、空气-0．1％乙醇水溶液和空气-水-活性污泥体系中的循环液速以及气含率随操作条件的变化规律。实验结果表明,循环液速随着表观气速的增加而增大,不同体系中的循环液速差别不大;导流筒内、外不同高度处的局部气含率均呈自下向上增大的趋势,且导流筒内部气含率高于导流筒外部的气含率。体系的聚并特性对平均气含率和局部气含率有较大影响。

Liquid Circulation Velocity and Local Gas Holdup in Air-lift Loop Reactor

In air-lift loop reactor, the effects of gas velocity on liquid circulation velocity and gas hold-up were experimentally studied in the different systems, namely air-water, air-0.1% alcohol and air-water- activated sludge. The liquid circulation velocity was measured by two separated electroconductibility probes and the gas holdup was determined by using the static pressure difference method. The experimental results show that the liquid circulation velocity increases significantly with the increase of gas superficial velocity, but the bubble coherence property has been found to have little influence on the liquid circulation velocity. The local gas hold-up inside/outside the draft tube in different vertical positions was also determined and the results indicate that the gas hold-up is apparently affected by the bubble coherence property and the gas superficial velocity. The local gas hold-up inside the draft tube is higher than outside at the same longitudinal position.