Prediction of Dispersed Phase Holdup in Scheibel Extraction Columns by a New Correlation

In this study, the effect of operating parameters on dispersed phase holdup in liquidliquid extraction process has been investigated. Three chemical systems (Toluene/Water, Butyl acetate/Water, and nButanol/Water) were utilized and holdup was considered in a wide range of interfacial tensions through a Scheibel extraction column. Various rotor speeds were examined on the certain velocities of dispersed and continuous phases. It was found that with increasing rotor speed in a Scheibel extraction column, the drop size was reduced and drops were trapped inside the packed so that an increase in the dispersed phaseholdup happened. An obvious increasing trend of dispersed phase holdup was observed as a result of increase in dispersed phase velocity for all systems operating under 2 different rotor speed, namely, 100 and 140rpm. However, the results showed that increase in the velocity of continuous phase would not make significant effect on the holdup. During examining the effect of both rotor speed and dispersed phase velocity, it was found that the holdup would be higher in the chemical system with the lowest interfacial tension compared with two other systems. An empirical correlation was also proposed to predict the dispersed phaseholdup with AARE of 8.72%.