Operational characteristics of oscillatory micro-screen emulsifier: Coupling effects and energy dissipation

• Investigated oscillatory woven metal microscreen emulsification characteristics.
• Oscillations decreased droplet size due to surface shear and energy dissipation.
• Using bi-surfactants in the dispersed and continuous phases reduced drop size.
• Droplet size modeled satisfactorily using torque balance and power density.
• Estimated energy requirement is lower compared to other emulsification methods.

Production of oil in water (O/W) emulsion using oscillatory high porosity woven metal microscreen (WMMS) is investigated both experimentally and theoretically. The investigation included coupling effects of design and operating parameters on droplet size and distribution. Results demonstrate the ability to produce emulsions with predictable characteristics and to achieve high dispersed phase concentrations at low energy requirements. Increasing oscillation intensity resulted in smaller droplet size due to the increase in both surface shear and surfactant transfer rate to the droplets surface. The expansion rate of the later increased with increasing the dispersed phase flow resulting in faster surfactant depletion. Using bi-surfactants in both the continuous and dispersed phases resulted in smaller droplet size due to lower interfacial tension. Decreasing the emulsification channel width decreased droplet size due to the increase in the relative surface shear as well as the energy dissipation density. The presence of surface roughness resulted in smaller droplet sizes but had an adverse effect on the dispersion uniformity, which was also affected by lateral vibrations. Both led to localized energy dissipation and droplets breakage near the edges. An order of magnitude assessment of power consumption showed favourable energy requirement (kW h/m3) of the proposed approach compared to other techniques.