Liquid entrainment in tray columns with downcomers

Abstract

In this paper a new dimensionless correlation for calculating the liquid entrainment of trays operated in the spray regime is presented. This correlation is generally valid for all types of trays, such as sieve, bubble cup, valve, tunnel, and cross-flow trays, with downcomers. It describes the data from the literature and new data obtained in columns with large diameter by Kozioł more exactly than any correlations known so far. Its validity was confirmed on systems with widely differing physical properties. According to the presented analysis of the influence of errors in the determination of liquid entrainment on the calculation errors of tray efficiency, the mean weighted absolute deviation between the calculated and the experimental data is the most important factor. A further aim of this work was the formulation of a new criterion to compare the accuracy of the correlations used in describing the liquid entrainment on a tray. Finally, a numerical example determining the entrainment according to the new correlation is presented.