An Ultrasonic Technique for Control of Hold-Up Profiles in Multistage Extraction Columns

Recent investigations on process control of holdup in liquid-liquid extractors implement single-point measurement techniques despite the existence of strong nonuniformities in hold-up profiles. In this work, the ultrasonic method for hold-up measurements reported by Bonnet and Tavlarides is employed to monitor hold-up profiles in a column extractor. The evolution of hold-up profiles is shown during the start-up of the operation and the transient period when a step change in rotational speed is imposed. The noninvasive character and the rapid response of the ultrasonic technique indicate its importance in column process control.