Experimental studies on the performance and analysis of an electrostatic coalescer under different electrostatic boundary conditions

The rate of coalescence in an electrocoalescer, which governs the residence time, sensitively depends upon the electrostatic conditions as well as the electrodes arrangement. An experimental study of a cylindrical electrocoalescer vessel for two different modes of operation is reported in this work. The design of the coalescer is optimized for the residence time and water separation. To justify the experimental findings and to unravel more physical insights, the single phase electrostatics is simulated using COMSOL Multiphysics software. The volume of the emulsion under the influence of 0.3–1.0 kV/cm electric field, calculated using COMSOL, correlates well with the water separation. Moreover, the simultaneous measurement of current suggests an ordering, that leads to an increase in size of the droplets and settling of drops in the normal operation. On the other hand, chaining and shorting leads to surge in current at high fields and seems to prevent water separation.