Method of picking a component with an intermediate evaporation temperature out of multicomponent mixture using two fractionating columns

The paper presents the method of picking a component with an intermediate evaporation temperature (with respect to low-boiling and high-boiling components) out of a multicomponent mixture. This problem usually arises in the chemical technology. It's solution requires the solution of the problem of the selection of the optimal separation sequence of a three-component mixture. The paper gives the rule for this selection and some conditions of the whole process's feasibility. It is also shown that the required assumptions could be done at the stage of preliminary design of the column cascade. (In Russian).