Chemical Engineering Journal, Vol.166, No.2, 715-725, 2011
Turbulently flowing liquid-liquid dispersions. Part I: Drop breakage and coalescence
A successful attempt to simulate turbulently flowing liquid-liquid dispersions was undertaken in this work where the turbulent dispersion/coalescence of drops was accurately predicted over a wide range of operating conditions using the model developed by Coulaloglou and Tavlarides (1977) [36]. Experimental data obtained from an intensified liquid-liquid reactor/contactor in which screen-type static mixers were used to superimpose an adjustable uniformly distributed turbulence field on the nearly plug flow conditions encountered in high velocity pipe flows were used to validate the model predictions. Drop size distribution and the Sauter mean diameter (when quasi-steady state conditions were assumed to be reached) were compared with the experimental results measured by photographic techniques and good agreement was obtained at different flow velocities and diverse screen geometries. The use of mutli-stage screen-type static mixers where alternating breakage-dominated and coalescence dominated regions exist allowed the development of accurate model parameters that may be used for simulating other more complex liquid-liquid contacting conditions such as those encountered in mechanically agitated tanks. (C) 2010 Elsevier B.V. All rights reserved.
Keywords:Breakage;Coalescence;Liquid-liquid dispersion;Drop size distribution;Population balance;Static mixers