Longitudinal dispersion in pulsed perforated‐plate columns

Abstract Experimental measurements have been performed for pulsed perforated‐plate columns of different sizes and geometry to obtain longitudinal dispersion coefficients for continuous and dispersed phases and size and holdup of liquid droplets dispersed in the columns. These quantities are correlated with operating conditions and column design, including the data published by different authors. Longitudinal dispersion coefficients for the continuous phase are shown to follow the backflow model. A superficial number of stages in series in each compartment is shown to come from inherent instability of fluid motion in the compartment. The longitudinal dispersion coefficient of the dispersed phase approaches that of the continuous phase with increasing pulse velocity. Holdup and mean size of droplets are correlated mainly on the basis of the rate of energy dissipation in the column fluid. Inclusion of dispersed‐phase viscosity is shown to correlate the holdup data successfully for different liquid‐liquid systems.