Effects of interaction between circulating or oscillating droplets on drop formation, free fall, and mass transfer

Abstract

The effects of interaction between circulating or oscillating droplets on drop formation, terminal velocity, and the continuous phase mass transfer coefficient during free fall were studied. To examine the mass transfer coefficient during free fall both end effects were eliminated by subtracting the mass transferred in a short column from that transferred in a long column. A correlation for the prediction of drop volume based on the equations of Scheele and Meister (1968) for non‐jetting drops, and of Meister and Scheele (1969a, 1969b) for drops formed under jetting conditions, has been developed. The terminal velocity of the drops was enhanced by vertical interaction with adjacent drops at values of L/dp < 5. The continuous phase mass transfer coefficient for circulating drops was reduced due to vertical interaction at L/dp < 10; however, for slightly oscillating drops it was not affected by vertical interaction over the range of 1.5 < L/dp < 20. By conducting experiments with single and triple nozzle arrangements, horizontal interaction effects were found to be negligible for both systems.

Measurement and Correlation of the Mass Transfer Coefficient for a Liquid-Liquid System With High Density Difference

“…The distance apart between two consecutive droplets was large enough ( > 60 mm) so that fluid motion was dampened before the next droplet arrives. Thus, interactions between drops should be negligible (Skelland and Vasti, 1985). Three samples were taken in each run and then analyzed by gas chromatography (GC7900).…”

Experimental investigation of the effects of the hydrophilic silica nanoparticles on mass transfer and hydrodynamics of single drop extraction

“…Single drop injections were adjusted to make drops more than 6 cm apart. Skelland and Vasti [22] have reported that interactions can be ignored for drops apart by at least 6 cm. Samples (6 cm 3 ) were withdrawn from the collected dispersed phase at the top to determine solute concentration using potentiometric titration.…”

Continuous Phase Mass Transfer Coefficients for Single Droplets Moving in an Infinite Droplet Chain

“…The same results were obtained. Skelland and Vasti (1985) have experimentally investigated the mass transfer coefficient on the continuous phase side by using one and three drop streams in a stagnant liquid. They showed that vertical interaction of drops caused reduction in mass transfer coefficient, whereas the effects of horizontal interaction were found to be negligible.…”