Modeling of Falling Film Molecular Distillator

Abstract

On the basis of the kinetic equation, a mathematic model for two‐components in the presence of an inert gas was developed to describe the falling film molecular distillation process. The heat and mass transfer in liquid film on the evaporating surface and the mass transfer in the vapor phase in the distillation gap are taken into account. This model may show the profiles of temperature and concentration of film and the profiles of density, temperature, and velocity of vapor in consideration of the feed rate, evaporation temperature, and inert gas pressure. The model can be applicable to simulating various operational situations in a falling film molecular distillator. The comparison of the experiment results with the model study results shows a satisfactory qualitative agreement between the experiment and the theory.

Keywords:

• Falling film still
• numerical simulation
• molecular distillation
• BGK equation

Acknowledgment

Supported by National Natural Science Foundation of China (No.20136010).