Droplet charge-to-mass ratio measurement in an EHD liquid-liquid extraction system

The application of a high voltage electric field to enhance the rate of mass transfer in liquid-liquid extraction has been an active subject of investigation in recent years. The electrohydrodynamic (EHD) forces generated by electric fields at a liquid-liquid interface have a potential application in chemical processing industry solvent extraction processes. In this work, the charge-to-mass ratio of droplets formed in an EHD liquid-liquid extraction system has been investigated experimentally and theoretically. The results reported from the present investigation, extending from the single discrete droplet regime (at low applied voltages) to the dispersed multi-droplet regime (at high applied voltages), indicate that the modified Rayleigh instability model and Vonnegut and Neubauer model can explain maximum droplet charge acquired in liquid-liquid systems, especially the modified Vonnegut and Neubauer model which can predict most of the experimental results when the applied electric field is high enough and EHD forces become dominant.