Minimum reflux mode regularities

A number of regularities of the minimum reflux mode are common for the ideal, nonideal, and even azeotropic mixtures. Among these regularities is the following each section trajectory at minimum reflux and at sharp separation is partially... 

The conducted analysis of product points evolution, depending on R for ideal mixtures, determines a number of the important qualitative regularities of the minimum reflux mode the existence of three classes of fractioning, the availability of one or two zones of constant concentrations in each section of the column, feasibility of various splits by means of a corresponding choice of two parameters of the mode -otR and D/F. 

These qualitative regularities have a general nature and apply not only to ideal mixtures, but also to nonideal ones. Only the possibility of analytic solution for the minimum reflux mode (Underwood equation system) and Unearity of separatrixes and of dividing surfaces and hypersurfaces of section regions Reg specific for ideal mixtures. The latter circumstance was also extended to nonideal mixtures in a number of approximate methods (Levy et al., 1985 Julka Doherty, 1990 Stichlmair et al., 1993). 

Knowledge about the distillation process regularities under minimum reflux is the background of the distillation theory, and this mode analyzing is the most important stage of the distillation column design. 

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