Polarization Characteristic of Droplet of Water-in-Oil Emulsion in a High Uniform Electric Field

In order to explore deeply electrodynamics mechanism of electro-demulsification, singular water droplet, as study object, in w/o (water-in-oil) emulsion is placed in high steady electric field, and ellipsoidal droplet polarization model is established. By the model, droplet´s polarization characteristic and its interrelated affecting factors are analyzed. The mathematic expression of polarization per unit volume of droplet in oil is obtained. Utilizing the expression, polarization per unit volume of a droplet, respectively in sunflower oil, palm oil and calibration oil, is simulated and calculated. The results show that oil-water interface tension and ratio of oil and water permittivity have an influence on droplet´s polarization directly. Relative error of droplet´s polarization per unit volume obtained by spherical drop model and ellipsoidal drop model is 22.5% in low electric field and 13.5% in high electric field. Therefore, ellipsoidal droplet polarization model is better for studying technology of electro-separating which used in oil and petroleum industries.