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Dielectrophoretic separation of a water-in-oil emulsion.

Dielectrophoretic separation of a water-in-oil emulsion.

Authors :
Shmyrov, Andrey
Mosheva, Elena
Mizev, Aleksey
Source :
Experimental Thermal & Fluid Science. Jan2025, Vol. 160, pN.PAG-N.PAG. 1p.
Publication Year :
2025

Abstract

Electric field-assisted separation is considered one of the most effective ways of dehydrating water-in-oil emulsions. In the uniform electric field usually used in electrodehydrators, electrocoalescence leads to droplet enlargement, thus accelerating their gravitational settling. Meanwhile, using a nonuniform field is expected to provide an additional tool for phase spatial separation due to dielectrophoresis while keeping the conditions favorable for electrocoalescence. This study aims to investigate experimentally the dynamics of water-in-oil emulsion in a nonuniform electric field and the efficiency of its separation due to the dielectrophoretic effect. A high-frequency field and emulsions with zero-density contrast were used allowing us to study the action of the dielectrophoretic force in the absence of electrokinetic phenomena and gravitational settling. We found that droplets always move towards the electric field strength gradient, eventually accumulating at the internal electrode. We demonstrate that the separation efficiency increases as the average droplet size, the voltage, the dispersion medium permittivity, and the initial droplet concentration increase. In the latter case the separation enhancement is due primarily to droplet coalescence, the rate of which increases appreciably with increasing concentration. We demonstrate that all the experimental results can be combined into unified dependence based on a simple physical model. [Display omitted] • Water-in-oil emulsion separation due to dielectrophoretic effect is studied. • Experiment statement allows studying without gravitational settling and electrophoretic effect. • Separation efficiency is studied under varying emulsion properties and electrical field characteristics. • Electrocoalescence in high-frequency non-uniform electric field goes without droplets chains formation. • The experimental data is combined into unified dependence based on a simple physical model. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
08941777
Volume :
160
Database :
Academic Search Index
Journal :
Experimental Thermal & Fluid Science
Publication Type :
Academic Journal
Accession number :
180630302
Full Text :
https://doi.org/10.1016/j.expthermflusci.2024.111301