界面湍动对湿壁塔液相传质系数的影响

选用乙醚的低浓度水溶液为研究对象，在湿壁塔中液相层流流动状态下，考察乙醚解吸过程中传质系数与Marangoni数之间的变化．实验结果表明当平行于界面的表面张力差超过临界值后，Marangoni界面湍动效应将发生，随之导致传质系数较之只依赖扩散传质时增大，并且传质效果的强化程度同Marangoni界面湍动的强度有关．进一步的实验数据拟合结果表明传质增强因子F同Ma数之间符合幂函数关系，结果有助于利用Marangoni界面湍动增强传质效果．

Influence of Interfacial Turbulence on the Mass Transfer Coefficient in a Wetted-wall Column

A wetted-wall column was set up to measure the change of mass transfer coefficient induced by interfacial turbulence. The ethyl ether aqueous solution was utilized and ethyl ether was desorbed by nitrogen gas in the wetted-wall column while laminar flow in the liquid phase was carried out along the wetted column in experiments. The interface turbulence induced by Marangoni effect happened in experiments when the difference of surface tension along the gas-liquid interface exceeded the critical number. When interface turbulence happened,the mass transfer coefficient was much larger than that occurring only in the process of diffusion. At the same time,the results of experiments showed that enhanced mass transfer coefficient depended on the intensity of interfacial Marangoni turbulence as well. Through defining Marangoni number on the base of surface tension difference along the gas-liquid interface,the intensified mass transfer was related to Marangoni number and the relationship between the enhancement factor and the Marangoni number was fitted to the power correlation, FOCMa^n, with the exponent item n from 0.7 to 1. Results from this work are useful for utilizing interface turbulence induced by Marangoni effect to enhance mass transfer in operation units of chemical industry and develop the new type of mass transfer device.