对比分析了几种主要的膜蒸馏传质模型,发现对于实验所用孔径较大的膜,应以Poiseuille流动为主要的传质模式,不能用单一的Knudsen扩散来预测膜通量。针对现有的传质模型所需计算参数多、计算过程复杂等问题,并出于简单易算的考虑,在斯蒂芬定律的基础上引入了膜材料特性修正系数和膜变形修正系数,给出了一个适用于空气隙膜蒸馏的工程预测模型,该模型直接使用热溶液和冷却水的温度来进行计算,虽然在个别点上误差较大,但其具有方程简单、易于计算的特点,仍不失为一种较好的工程预测模型。
The comparative analysis of several membrane distillation of the main mass transfer model has been done. It indicated that the Poiseuille flow was main mass transfer method for big pore size membrane materials. The Knudsen diffusion model can not be used singly in prediction. A simple model based on the Stefan law for the air gap membrane distillation was proposed based on easy calculation. This model can be calculated directly by hot solution temperature and cooling water temperature that can be measured in experiment. This model is simple, the parameter of this model is easy to measure and compute except for big error in some points. It is a good engineering prediction model.