Drop size distributions in dispersed liquid-liquid pipe flow

This paper examines drop size distributions in a 0.063 m pipe for a two-phase mixture of kerosene and aqueous potassium carbonate solution. Measurements have been made for both vertical upflow and horizontal geometries, for mixture velocities ranging from 0.8 to 3.1 m/s. Two optical measurement techniques, a backscatter technique using a Par-Tec 300C and a diffraction technique using a Malvern 2600, have been used to obtain the drop size distributions of the dispersions created. Both measurement techniques have been found to be limited to different concentration ranges. Stratification of drop size was observed for low mixture velocities in a horizontal geometry. This did not occur for the vertical geometry. The drop distributions obtained were found to fit an upper limit log-normal distribution (ULLN). The theory of Hinze has been found to agree well with experimentally determined values of maximum drop diameter at low dispersed phase concentrations. At high concentrations, neither Hinze theory, nor a modified version proposed previously, adequately describe the data obtained. (C) 2001 Elsevier Science Ltd. All rights reserved.