Ah&act-Benzene drops were formed in continuous media of water and glycerine of varying physical properties. The effect on drop volumes of variables like volumetric flow-rate, interfacial tension, continuous phase viscosity and capillary diameter was studied. An equation has been developed, based on a two stage drop formation mechanism, which predicts drop volumes within an average error of 7 per cent for the range of physical properties employed in this investigation.
INTERFACIAL area is a very important factor in all mass transfer operations. Thus a sound design of a spray tower requires a knowledge of the drop sizes consistent with the properties of the liquids used and the design and size of the dispersing nozzles. Investigations on drop formation in the absence of mass transfer provide by no means the exact information required for such a design but provide one with an idea of the order of drop sizes involved in such situations. HAYWORTH and TREYBAL [l], and NULL and JOHNSON [2] attempted to predict drop sizes as a function of variables like interfacial tension, viscosity of continuous phase, nozzle diameter and flow rate of the dispersed phase through the nozzle. The equation developed by HAYWORTH and TREYBAL [l] is semi-empirical and is based on a force balance made by expressing the various contributing forces acting on the drop as fractions of the total drop volume. This procedure is probably not wholly justified since the exact instant at which the forces act is not known nor is their quantitative contribution to the total volume. NULL and JOHN-SON [2] based their model on the geometry of the drop formation process. This model neglects the effect of viscosity of the continuous phase which seemed to play an important role in the model proposed by HAYWORTH and TREYBAL [ 11. Whereas HAYWORTH and TRJZYBAL [l] find only one peak on the flow-rate versus drop size curve, NULL and JOHNSON [2] find two peaks. The latter made a comparison of the predictions of drop sizes when the two models were applied to their data and report