Experimental and theoretical analysis of emulsification characteristics using a high porosity microscreen under oscillatory shear conditions

Application of oscillations for production of oil-in-water emulsion using high porosity woven metal micro-screen (WMMS) has been investigated. An analytical model has been developed for predicting the average droplet size that took into consideration the dynamic interaction between the dispersed phase flow and oscillation parameters. The effect of deviation from simple Stokes oscillatory flow analysis on the hydrodynamic and diffusion layer has been considered. It was found that increasing oscillation intensities decreases the average droplet size due to both the increase in the detachment forces as well as the increase in surfactant mass transfer rate, which decreases the interfacial tension holding force. On the other hand, increasing the dispersed phase flow rate had dual opposite effects. First, it increases the rate of surfactant depletion, which increases the interfacial tension holding force leading to larger droplet size. Second, it increases the active pore fraction and the probability of steric hindrance between droplets forming at adjacent holes which creates an additional detachment "push-off" force that leads to smaller droplet size. The model predictions agreed satisfactory with the experimental data of this investigation as well as selected data from previous investigations by different authors with R-2 = 0.96. (C) 2014 Elsevier B.V. All rights reserved.