(116d) Direct Measurement of Droplet Coalescence in a Pulsed Disc and Doughnut Column

The population balance model (PBM) has been widely used to predict droplet size distribution in various industrial processes. In previous study, Zhou et al [2017. Direct measurement of droplet breakage in a pulsed disc and doughnut column. AIChE Journal, 63(9), 4188-4200] directly measured the droplet breakup frequency and daughter size distribution in a pulsed disc and doughnut column (PDDC). The research of droplet coalescence is more complex than breakage owing to the effect of the flow field on the droplet and the interaction between the droplet. In this work, experiments were carried out in a PDDC with a high-speed online camera to observe the coalescence events to investigate the effects of operation parameters on droplet coalescence. Experimental data on droplet size distribution and droplet coalescence frequency function were obtained by processing the images. The influence of pulsation intensity and holdup was quantitatively studied. The results indicated that the droplet coalescence frequency increases as the pulsation intensity or holdup increases.