Rate of rise or fall of liquid drops



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 centiposes; 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-drop-diameter 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.