Coalescence of Water Drops in Oils under Pulsatile Electric Fields

The coalescence of water drops in oils may be enhanced by the application of an electric field. However, the process of coalescence could cause secondary drop formation, a feature which is undesirable as it reduces the efficiency of water separation. In this work the effect of pulsed electric field is evaluated. With pulsatile electric fields higher field strengths can be applied for systems having a high water content without causing field breakdown. Three waveform types, i.e. square, sinusoidal and sawtooth waves have been applied to drop-interface coalescence and their effect analysed. It is shown that the sinusoidal and sawtooth waveforms are most effective in reducing the secondary droplets formation

Keywords:

electro-coalescence , secondary droplets , pulse electric field