Dynamic simulation of agitated liquid—liquid dispersions—II. Experimental determination of breakage and coalescence rates in a stirred tank

Abstract

Using the theoretical procedure outlined in the first part of this work, breakage and coalescence rates were determined experimentally in a stirred tank. After reaching steady-state conditions, the intensity of agitation was suddenly changed and the variation in drop size distribution with time was monitored. The coalescence and breakage constants were evaluated by optimising the fit of the experimental results with the theoretical solution of the model equations. No a priori assumptions concerning the dependence of the interaction rates on drop size, system properties and operating conditions were made. Precise techniques for measuring the drop size distribution in turbulent dispersions were developed and tested. Empirical equations for dependence of breakage and coalescence constants on drop volume, holdup and system properties were derived.