ABSTRACT
For the most part in this book, multistage columns were studied in terms of equilibrium stages, and a stage was assumed to represent a column tray. Multistage vaporliquid countercurrent flow for the purpose of separation can also take place in packed columns. In these devices, instead of trays, the column is filled with an inert packing material designed for maximum mass transfer between the vapor and the liquid and for low-pressure drop. The vapor and liquid compositions vary continuously with packing height rather than discretely as in trayed columns.
