Vaporization from Liquid Film of Binary Mixture in a Centrifugal Molecular Still

Abstract

A mathematical model of heat and mass transfer for the rotating evaporator surface on a centrifugal molecular still has been developed for binary mixtures. A numerical solution for the relationship between the rate of distillate and its composition and an approximate solution under a special condition are proposed, and effects of some dimensionless parameters on the evaporation phenomena are discussed. The validity of this mathematical model was demonstrated by evaporation experiments for two binary systems; DBP (dibutyl phthalate)-EHP (di-2-ethylhexyl phthalate) and EHP-EHS (di-2-ethylhexyl sebacate), using two centrifugal molecular stills. Experimental data agreed well with the numerical solution and the usefulness of the mathematical model was elucidated.