Design of Fractionating Columns: I. Entrainment and Capacity

Abstract

Entrainment in fractionating columns affects the color of the product and the plate efficiency, and limits the maximum vapor velocity that will give satisfactory operation. Using a theoretical equation and empirically derived constants, an expression is obtained for the maximum allowable vapor velocity in a column which is dependent upon the quantity of entrainment that can be tolerated according to operating conditions. Values of the constants to be used for determining the capacity of columns for different types of services under ordinary operating conditions are suggested. The effects of intermediate reflux, the ratio of liquid overflow to vapor rising in the column, plate spacing, and allowable entrainment are discussed so that the maximum vapor velocity for satisfactory operation of fractionating columns under various conditions may be estimated in a fairly satisfactory manner. © 1934, American Chemical Society. All rights reserved.