Hydrodynamic behaviors of rotating perforated disk column(RPDC) were studied with an emulsion-water system. The emulsion was dispersed in water and its holdup was measured. The effects of column dimensions and operating conditions on holdup and characteristic velocity were studied. By using dimensional analysis

the authors obtained two experimental correlations for estimating holdup and characteristic velocity respectively. Drop size distributions were studied photographically. The experimental results showed that drop size distributions could be described by upper limit log-nomal distribution.