Abstract: A New method, based on dynamic method of double phase circulation for measurement of vapor liquid equilibrium data of salt-containing system, is present,and a new apparatus developed.To solve the problems existing in the common determination method for salt-containing vapor liquid equilibrium, our work is based on the principle of double phase circulation method and the determination procedure is divided into two steps.In the first step, the quasi-static method is used to measure the bubble point line data (t,x) which does not require composition analysis,and in the second step, by using the same apparatus CS- Ⅱ multipurpose VLEdetermination apparatus, the dew point line data (t, y) of the same constant salt concentration in equilibrium liquid phase is determined.The new VLBdetermination apparatus with a pump-like stirrer can make the circulation so steady that it can avoid effectively the fluctuation and the rush of the liquid flow which often happens when double phase circulation apparatus are used for salt-containing systems.The error equation of quasi-static method for the bouble point measurement of salt-containing system is deduced from the relationship of material balance concerned,the verification work was done experimentally, including the examination of the applicability of the new apparatus in saturated salt-containing system and the determination of VLEdata of CaCl₂-acetone(1)-methanol(2) system at normal pressure and 5% CaCl₂ concentration in equilibrium liquid phase.The experimental data agree finely with literature data.

Key words: Salt-containing vapor liquid equilibrium, Quasi-static method, Multipurpose VLE determination apparatus, Bubble point line, Dew point line