Folds on the temperature surfaces of heterogeneous multicomponent liquid-vapor systems

Regularities in the behavior of folds on the surface of equilibrium temperatures for multicomponent two-phase mixtures are studied. The concept of the multiplicity of a fold on the surface of temperatures is introduced.     

Thermodynamic Analysis of the Wilson Model Using Partial Excess Functions

An approach to thermodynamic analysis of models of liquid solutions is developed. The approach is based on studying local characteristics of the concentration dependences of the partial excess molar functions. The applicability region is established, and constraints on the parameters of the Wilson equation are found.     

Algebraic Sum of the Indices of Singular Points for Complexes of Various Dimensionalities

New equations for the algebraic sum of the indices of singular points are suggested for complexes of various dimensionalities.     

Flowsheet Synthesis Strategy for Irreversible Zeotropic Distillation

A strategy is suggested for the synthesis of the set of distillation flowsheets involving complex columns. The strategy is based on the transformation of flowsheets consisting of simple columns.     

Manifestation of ideality in nonideal ternary mixtures

The article deals with diagrams of three-component two-phase nonideal systems with an ideal vapor phase. One-dimensional manifolds along which the liquid phase of the mixture behaves as an ideal system are considered.     

Calculation of the liquid — Vapor phase equilibrium of nonideal systems

Conclusions It has been found that approximations made to equilibrium data by means of Auslander's equation ensure high accuracy during calculation, but in some cases lead to a discontinuity in the functions so that significant errors are obtained.Equations have been derived which exclude these discontinuities and they have been used for compiling a program (on a Minsk-2 electronic computer) for treating experimental data on phase equilibrium in binary mixtures and on the dependence of the boiling point on composition for multicomponent mixtures.Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 2, pp. 41–44, February, 1969.     

New forms of the azeotropic relationships for two-dimensional concentration complexes

The equations for the sum of Poincaré indices of the singular points in the tie-line vector field are written in new forms for various two-dimensional complexes. The equations are applied to systems at phase and chemical equilibria.     

Thermodynamic modeling of liquid crystal-nonmesogen systems in the approximation of the theory of regular solutions

Nematic (or smectic-nematic) liquid crystal-nonmesogen systems are investigated by thermal analysis methods. A method for predicting the T-x diagrams of these systems using a model of regular solutions is proposed. The method gives good agreement between the predicted and experimental data in determining the phase separation in a system and calculating solubility polytherms. Specific features of calculation of the solubility parameter of liquid-crystal compounds are considered.     

Trees of reversible distillation trajectories and the structure of trajectory bundles for sections of adiabatic columns

The arrangement of reversible distillation trajectories is related to the structure of trajectory bundles for sections of two- and three-section adiabatic columns. An algorithm for constructing trees of reversible distillation trajectories in the concentration simplex is described in detail. Numerous calculation examples for zeotropic and azeotropic mixtures are presented to demonstrate specific features of the arrangement of reversible and adiabatic distillation trajectories.     

Observance of the Gibbs-Konovalov law at complex singular points of two-phase multicomponent systems

The observance of the Gibbs-Konovalov law is proved for all complex singular points of two-phase multicomponent systems.