Rate of rise or fall of liquid drops

Abstract

Measurements of the terminal velocity of liquid drops immersed in an insoluble liquid were made for eleven liquid systems, covering a wide range of physical properties: continuous-phase density 0.960 to 1.145 g./cc., viscosity 0.93 to 1.56 centipoises; dispersed-phase density 0.807 to 1.674 g./cc., viscosity 0.59 to 72.1 centipoises; interfacial tension 0.3 to 42.4 dynes/cm. A correlation of the data was developed for each of the two velocity-dropdiameter regions which permits easy computation of the drop velocities. The correlations are shown to reproduce the present data and much of the published data very satisfactorily.Photographs permitted measurement of the drop eccentricities, which are shown to be a function of the drop diameter, density difference, and interfacial tension.Several recent papers (S, 5, 6) EXPERIMENTAL DETAILSThe drops were allowed to rise or fall in a glass-walled tank of square cross section 10 by 10 in., 40 in. tall, made from %-in. plate glass and brass angles, with brass end plates, the whole kept leaktight with Permanite cement. The tank was filled with the liquid through which the drops were to move (continuous liquid). Liquid to form the drops (dispersed liquid) flowed by gravity from a separatory-funnel reservoir through two pipettes in series, of 1-and 5-ml. capacity, through a needle valve to control the rate of flow, and thence to a brass or stainless steel sharp-edged nozzle, from which it issued into the continuous liquid. The nozzles entered the tank through the upper or lower end plates, depending upon whether drops were to fall or rise. Nine nozzles were used, varying in internal diameter from 0.018 to 0.516 in., in order to obtain the desired range of drop sizes. The temperature of the system was measured by a thermometer suspended in a corner of the tank.

Liquid‐phase mass transfer in spray contactors

“…Correlations by Klee and Treybal (1956), Hu and Kintner (1955), Johnson and Braida (1957), Edge and Grant (1971), and Grace et al (1976) were discussed by Skelland et al (1987) and are shown in Appendix B. These correlations were developed for a liquid droplet moving at terminal velocity through another liquid phase, and they may not be easily extrapolated to the case of liquid droplets in a gas.…”

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

“…Comparison of calculated results with criterion values, showed that most drops were under the oscillation condition. Klee and Treybal (1956) proposed an expression for the critical diameter cr , d Figure 2. Note that the diameters of droplets ranged from 1.66 to 3.49 mm and were larger than the calculated d cr .…”

LLECMOD: A Bivariate Population Balance Simulation Tool for Pulsed Liquid-Liquid Extraction Columns

“…A number of authors describe the suitability of velocity correlations for specific droplet size ranges or certain physical properties [26,[37][38][39][40]. A selection of these velocity correlations has been implemented in simulation program.…”