Prediction of low-concentration components of condensation of multicomponent mixtures of hydrogen isotopes

In this paper we develop a model for multicomponent condensation for a mixture of hydrogen isotopes based upon the molecular theory of transport phenomena. The condensation rate at the interface condensate-vapor film is expressed as the mass flux vector at the interface. In the vapor film the behaviour of molecules is described by the equations of mass diffusion. At the equilibrium we considered the non-idealities both in the vapor and the liquid phases. We computed the specific volumes of hydrogen isotopes with the aid of Redlich-Kwong equation of state on vapor phase. For the fugacity coefficients we computed the enthalpy of evaporation with the aid of Clapeyron-Clausius equation and with the equation of saturation pressure as a function of temperature. For the coefficient of activity on liquid phase we made a comparative study of Hildebrand and Margules theories' applicability to mixtures of hydrogen isotopes. At the end some Gibbs diagrams for ternary mixtures of hydrogen isotopes are shown. (authors)