Comparison of mean drop sizes and drop size distributions in agitated liquid–liquid dispersions produced by disk and open type impellers

A comparison is made of drop diameters produced by a disk and an open type six-blade impeller having the same impeller diameter and width and rotated at the same speed. Drop size measurements in situ at 200, 250, 300, 350, 400 and 450 rpm and at hold-up fractions 0.01, 0.025, 0.05 and 0.10 showed that always the Sauter mean drop diameters produced by the open style impeller were 6–82% larger than the ones produced by the disk impeller. Plots of ln d32 versus ln N and ln dmax versus ln N gave straight lines. Plots of d32 versus dmax gave relationships not quite linear.