Stationary points residue curve bundle

Points of pure components and azeotropes are stationary or singular points of residue curve bundles. At these points, the value dXi /dt in Eq. (1.11) becomes equal to zero. A stationary point at which all residue curves come to an end is called a stable node (the temperature increases in the direction of this point). A specific point at which all residue curves start is called an unstable node (the temperature... 

The totality of all bonds characterizes the mixture s structure. The bond serves as the elementary nonlocal characteristic of the residue curve bundle structure. Bonds form bond chains. The bond chains of maximum length connect the unstable node A and the stable node A+ of the distillation region Reg". Let s call a polyhedron formed by aU stationary points of one maximum-length bond chain and containing aU components of the mixture a distillation subregion Reg. ... 

Bonds between the stationary points (points of the components and azeotropes) and distillation subregions Reg j are the structural elements of the distillation regions. Residue curve bundle structure of multicomponent mixtures can be described with the help of a structural matrix that reflects the bonds available between the stationary points. 

Name the stationary points of types of residue curve bundles ... 

The boundaries separating one bundle from another are specific residue curves that are called the separatrixes of saddle stationary points. In contrast to the other residue curves, the separatrixes begin or come to an end, not in the node points but in the saddle points. A characteristic feature of a separatrix is that in any vicinity of its every point, no matter how small it is, there are points belonging to two different bundles of residue curves. The concentration space for ideal mixtures is filled with one bundle of residue curves. Various types of azeotropic mixtures differ from each other by a set of stationary points of various types and by the various sequence of boihng temperatures in the stationary points. 

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