Martin Henschke

Determination of a coalescence parameter from batch-settling experiments

Abstract Until today, neither measurements nor theory are able to describe the complex processes at the interface that occur during coalescence in liquid–liquid dispersions in a detailed way. With the model presented in this study, it is possible to characterize coalescence processes with a single integral coalescence parameter. This parameter is obtained from a simple batch-settling experiment. If experimental data are evaluated based on this model, it is ensured that the parameter is independent of the experimental equipment, mixing intensity and volume fraction of the dispersed phase. Furthermore, the drop size in the dense-packed zone can be determined with this model.

Mass transfer by free and forced convection from single spherical liquid drops

Abstract Numerical simulations of the mass-transfer of droplet in a continuous phase were done for a conjugate problem. The effect of free and combined convection on the mass transfer was investigated by solving the governing equations using the finite element method. The results show that the mass transfer depends very strongly on the flow conditions. The effect of free convection on mass transfer at high Reynolds number is small. The mass transfer by the combined free and forced convection for a rising drop was found to be smaller than that for a falling drop. The simulation was limited to Re c ⩽20.