Effect of inert gas on evaporation and condensation process at high vacuum

Based on Bhatnagar-Gross-Krook(BGK) equation, a new scheme for multi-component flow calculations between two closed surfaces of evaporation and condensation was developed. It was used to simulate the vapor behaviors dibutylphtalate(DBP)-dibutylsebacate(DBS) system in the presence of an inert gas. According to the calculated results,the increase of evaporation temperature,condensation temperature,and distance between evaporation and condensation surfaces can decrease the evaporation efficiency,in which the rise of the condensation temperature can remarkably decrease the evaporation efficency.When inert gas pressure is much higher than the saturated vapor pressure for liquid on the evaporation surface,the evaporation efficiency trends to zero.