Hydrodynamics of a vibrating perforated plate extraction column

Abstract

AbstractHydrodynamic behaviour of several liquid‐liquid systems has been measured in a 5 cm diameter extraction column agitated by finely perforated plates vibrating at frequencies (f) 10–100 Hz and amplitudes (a) 0.024–1.5 mm. The Sauter mean droplet diameter is generally in the range 0.1 to 1 mm. It has been correlated empirically with af2, system properties and operating conditions. Dispersed phase holdup, when plotted against the product af, showed minimum values corresponding to the transition from mixer‐settler to emulsion regime. Holdup was also found to be affected by mass transfer and its direction. Entrainment of fine droplets in the continuous phase occurs at high agitation levels, but can be reduced by the addition of coalescence plates at the base of the column. Energy dissipation rates greatly exceed predictions from the quasi‐steady‐state model.