Influence of physical properties on drop size distributions of stirred liquid-liquid dispersions

An experimental investigation was carried out to analyse the influence of coalescence behavior on drop size distributions in stirred liquid-liquid dispersions. An endoscope measurement technique was applied that allowed the determination of drop sizes even with high volumetric dispersed phase fractions phi of up to 0.5. The influence of pH and addition of ions was studied by shaking and stirring experiments. For high coalescence rates, the results show self-similar drop size distributions independent of all other parameters. With low coalescence rates the Sauter diameter d(32) decreases and the distributions become narrower. When phase ratios were increased the common correlation d(32)similar to (1 + const. phi) We(-0.6) did not lead to a reliable description of the mean drop sizes due to coalescence effects.