Hydrodynamic characteristics and extraction performance of multistage liquid-liquid column extractor with active turbine impeller

The hydrodynamic characteristics and extraction performance of a multistage liquid-liquid extraction column with a novel impeller which is equipped wi th static mixers on a disc are study experimentally. The hold up of the dispersed phase varies along the height of the column. T he holdup at the first stage of the column increases with increasing disper sed phase flow rate. It decreases in the region of low flow rate of the dis persed phase and high impeller speed, and increases via a minimum value in the region of high flow rate of the dispersed phase and heigh impeller spee d, and increases in the region of low impeller speed with increasing contin uous phase flow rate. It also increases in the region of low flow rate of t he continuous phase and decreases via a maximum value in the region of high flow rate of the continuous phase with an increase in impeller speed. In t he other stages, the holdup increases with increasing dispersed phase flow rate and impeller speed. However, the effect of continuous phaseing flow ra te on hold up is not significant. The dispersed flooding flow rate increase s with increase continuous phase flow rate and then decreases via a maximum value with the impeller speed. The theoretical stage number per unit colum n height increases with increasing total flow rate of dispersed and continu ous phase, and then decreases via a maximum value with the impeller speed. The theoretical stage number per unit column height increases with increasi ng total flow rate of dispersed and continuous phase, and then decrease via a maximum value with the impeller speed. The performance is evaluated by t he theoretical stage number per unit column height and is somewhat higher c ompared with those of other extractors in the literature. The meshwire sett ed on the stator rings has a remarkable effect on extraction efficiency, an d is found to have the function of settling of dispersed phase.