Experimental investigation concerning the effect of mass transfer direction on mean drop size and holdup in a horizontal pulsed plate extraction column

Vertical extraction columns meet the needs of industrial applications, but when height limitation (especially in indoor applications) is a concern it is required to use horizontal columns. Considering the significant role of mass transfer in the sizing and scale-up of horizontal extraction columns, no analytical and experimental investigations have been conducted in this regard. In the present research, the effect of operating parameters including pulsation intensity and phase flow rates on the mean drop size and the dispersed phase holdup values was investigated in a horizontal pulsed sieve-plate column under both mass transfer directions for the toluene-acetone-water, n -butyl acetate-acetone-water and butanol-acetone-water systems. The results show that holdup decreases first and then increases with an increase of pulsation intensity. Increasing dispersed phase velocity also increases holdup. The mean drop size decreases with an increment of pulsation intensity, whereas flow rates of both phases have little impact. Moreover, it is observed that the presence of mass transfer significantly affects the mean drop size and holdup. Finally, new correlations were proposed for the prediction of mean drop size and holdup based on operating variables and physical properties of the systems with and without mass transfer. Average Absolute Relative Error (AARE) of the correlations was between about 6.83-15.38% for their optimized constants. A schematic diagram of the horizontal pulsed plate column has been used.