The aim of the paper is to present a rigorous mathematical model and simulation results of CMSMPR vacuum crystallizers in which both the cooling and evaporation effects of the vacuum cooling have significant influence on the generation of supersaturation. The non-isothermal model involves also the energy and mass balances of the vapor phase. By means of the resulting model, the dynamic behavior as well as the performance characteristics of the vacuum crystallizers are examined. The effects of boiling rate, feed flow rate, feed temperature and feed concentration on the temperature and solute concentration are studied.