ILAR中醇及电解质对非牛顿流体中气-液传质的影响

在-气升式内环流反应器中试验考察了非牛顿流体羧甲基纤维素钠(CMC)中的气泡聚并现象以及表面活性物质对液相体积传质系数的影响。结果表明,非牛顿流体中气-液传质效率随黏度的增加而降低,其原因是黏度增加使Taylor泡的尾流趋于稳定,降低了液相扰动,气泡间易聚并,从而气-液传质效率低。向非牛顿流体中添加醇类物质会影响气-液传质行为,对于聚合物含量低的流体,添加微量醇可以促进气-液传质,聚合物含量高的非牛顿流体,微量醇的加入反而不利于气-液间传质过程。非牛顿流体在ILAR上升管中的气含率随着黏度的增加变化不大,而下降管中的气含率有所提高。

Effects of Alcohol and Electrolytes on Hydrodynamics and Mass Transfer in Viscous Non-Newtonian Liquids in an Internal Loop Airlift Reactor

A study focusing on coalescence phenomena of non-Newtonian fluids and the effect of surface active compounds on the liquid-side volumetric mass transfer coefficient of oxygen in solutions of carboxymethylcellulose(CMC) polymer is carried out in an internal airlift loop reactor.The experimental results show that mass transfer rate of gas-liquid decreased with increasing viscosity in non-Newtonian fluids.Owing to increasing viscosity,the wake instabilities behind the Taylor bubble tend to disappear and induce the coalescence behavior of bubbles.The addition of alcohol into the solutions of polymer can influence mass transfer behavior in gas-liquid two phase.For low concentration of solution,addition of minus alcohol increases mass transfer, but when CMC concentration increases gradually,surface active compound decreases mass transfer.Also,with increasing viscosity gas holdup in the riser changes slightly and that in the downcomer increases in non-Newtonian fluids.