FLUID-DYNAMICS AND MASS-TRANSFER IN THE TOTAL CAPACITY RANGE OF PACKED-COLUMNS UP TO THE FLOOD POINT

Up to now, the only equations that were known for calculating mass tra nsfer during two-phase countercurrent flow in packed columns were thos e that apply to the range extending up to the loading point, The gas a nd liquid streams flow separately through the column below but not abo ve this point. Above it, the shear stress in the gas stream supports a n increasing quantity of liquid in the column, with the result that th e liquid holdup greatly increases. Finally, at the flood point, the li quid accumulates to such an extent that column instability occurs. Mas s transfer in this upper loading range can be described if these fluid dynamic relationships are taken into consideration. The algorithm tha t is presented here for its prediction is based on theoretical and exp erimental studies.