Hydrodynamics and mass transfer characteristics of a scheibel extractor. Part II: Backmixing and stage efficiency

The transfer of acetone between the toluene phase (dispersed) and the aqueous phase (continuous) has been measured along the length of a four‐stage Scheibel column packed with material preferentially wetted by the dispersed phase. (A Scheibel stage is defined as one mixing section plus one packing section.) The column concentration profiles were obtained by applying a new technique developed for this investigation. A parameter model‐fitting exercise has been developed to select the most appropriate mathematical model that quantifies the extent of backmixing in the dispersed and continuous phases and evaluates the stage efficiency. Overall dispersed phase mass transfer coefficients were estimated using the drop size and holdup data presented in Part I, and these have been compared with the published correlations based on single drop mechanisms.