PREDICTION OF DROP SIZE, DISPERSED-PHASE HOLDUP, SLIP VELOCITY, AND LIMITING THROUGHPUTS IN PACKED EXTRACTION COLUMNS

Empirical correlations for the prediction of drop size, dispersed-phas e holdup, slip velocity, and maximum throughputs in packed columns are presented. Published experimental results obtained with both random a nd ordered packings are considered. The drop-size correlation, which i s based on measurements from 376 runs with and without mass transfer f rom nine different sources for conditions when the continuous phase we ts the packing, reproduces the data with an average absolute value of the relative deviation of 15.7%. A large bank of data (2023 points wit h and without mass transfer from 10 different groups of investigators; continuous-phase wetting; d(p) > d(p, cr) for random packings; phi < phi(f)) has been used to develop a correlation for the prediction of d ispersed-phase holdup. The same body of data has also been used to der ive a correlation for slip velocity without using holdup. By using the correlation for dispersed-phase holdup, the average absolute values o f the relative deviation in holdup and slip velocity are 18.7 and 16.4 %, respectively. The corresponding figures for the slip-velocity corre lation are 20.1 and 15.6%, respectively. On the basis of data from 845 measurements with both continuous-phase and dispersed-phase wetting, an equation for maximum throughputs is derived which reproduces the da ta with an average absolute value of the relative deviation of 19.5%.