基于浓度/速度场测量的吸收过程液相传质系数

针对矩形流道内气、液流体的并流吸收传质过程，分别应用实时激光全息干涉术和激光多普勒速度仪对不同气、液流速下液相内近界面浓度分布与速度分布进行了实验观测.结果表明，边界层内浓度分布呈指数下降，流速越大梯度越陡，且速度边界层厚度要大于浓度边界层厚度.建立了通过物料衡算求算液相传质系数的方法.得到了不同条件下平均液相传质系数，并与Whiteman’s双膜理论的计算结果进行了比较.

Liquid mass transfer coefficient estimation for absorption based on measurement of concentration/velocity distributions

The process of absorption of CO2 in ethanol was studied in a transparent channel under various flow conditions of a co-current gas-liquid flow, and the concentration and velocity distributions in the liquid in the vicinity of gas-liquid interface were measured with holographic interferometry and laser Doppler anemometer respectively.An exponential increase of concentration within the boundary layer could be observed.The concentration gradient increased with increasing velocities of liquid and/or gas and the velocity boundary layer was thicker than that of concentration.A mass balance based approach was used for estimating liquid mass transfer coefficients, and average mass transfer coefficients in the liquid phase were obtained for different flow conditions.The results were compared to those calculated with the Whiteman’s two-film model.