Considerations for Scaling Up Agitated Extraction Columns

ABSTRACT Designing an agitated extraction column from basic principles without obtaining pilot scale data is risky. Theoretical calculations are unreliable because of coalescence effects, variations in physical properties and flow rates along the length of the column, and especially contamination in commercial systems. Wetting phenomena, the presence of solids, the tendency to form emulsions, and density gradients in the continuous phase are additional factors that dictate the need for pilot scale testing. The pilot scale column performance should be optimized with respect to volumetric efficiency and arrangement of the column internals. Empirical scale-up procedures are presented for three types of agitated extraction columns.