Review of the Dynamics of Coalescence and Demulsification by High-Voltage Pulsed Electric Fields

Abstract

The coalescence of droplets in oil can be implemented rapidly by high-voltage pulse electric field, which is an effective demulsification dehydration technological method. At present, it is widely believed that the main reason of pulse electric field promoting droplets coalescence is the dipole coalescence and oscillation coalescence in pulse electric field, and the optimal coalescence pulse electric field parameters exist. Around the above content, the dynamics of high-voltage pulse electric field promoting the coalescence of emulsified droplets is studied by researchers domestically and abroad. By review, the progress of high-voltage pulse electric field demulsification technology can get a better understanding, which has an effect of throwing a sprat to catch a whale on promoting the industrial application.

Electric Field-Assisted Agglomeration of Trace Nanoparticle Impurities for Ultrahigh Purity Chemicals

“…Based on research conducted by Peng et al, particles polarized by an electric field in a solution experience an attractive force, leading to their aggregation. 13 Assuming that μ 1 and μ 2 are the dipole moments of two polarized particles, the electric field energy (W) between the two polarized particles can be described as follows.…”

“…Based on research conducted by Peng et al, particles polarized by an electric field in a solution experience an attractive force, leading to their aggregation . Assuming that μ 1 and μ 2 are the dipole moments of two polarized particles, the electric field energy ( W ) between the two polarized particles can be described as follows. W = μ 1 μ 2 4 πε 0 ε 2 d 3 ( 3 cos θ 2 − 1 ) μ 1 = 4 π r 1 3 ε 0 ε 2 E ( ε 1 − ε 2 ε 1 + 2 ε 2 ) , 0.25em μ 2 = 4 π r 2 3 ε 0 ε 2 E ( ε 1 − ε 2 ε 1 + 2 ε 2 ) where d is the distance between two particles, r 1 and r 2 are the radii of two particles, ε 0 is the vacuum dielectric constant, ε 1 and ε 2 are the relative dielectric constants of the particle and solution, respectively, and E is the intensity of the electric field.…”

Simulation Analysis of Emulsion Droplet Excited by Chaotic Frequency Pulse Electric Field

“…Eow et al [2][3] think that using appropriate frequency of pulse electric field can improve the efficiency of oil demulsification and dewatering. The research [4] shows that the main reason for the high efficiency demulsification of pulsed electric field is that the droplets in the oil will undergo harmonic resonance with sharp expansion and deformation in a specific pulse frequency range, which will increase the collision probability of adjacent droplets and weaken the mechanical intensity of the oil-water interfacial film, resulting in effective coalescence and demulsification.…”

On-Demand Droplet Merging with an AC Electric Field for Multiple-Volume Droplet Generation

“…23 If the droplets flow in parallel to the uniform field, an attractive force results from the dipole-dipole interaction. 24 This force brings the droplets closer, increasing in strength as the distance between the droplets decreases. 15 Subsequently, film thinning occurs where the rate of thinning can be tuned by the applied electric field.…”

“…The droplet is accordingly stretched in the same direction as the electric field due to the induced electric Maxwell stresses on the surface, with Taylor cones formed under high electric field strength . If the droplets flow in parallel to the uniform field, an attractive force results from the dipole–dipole interaction . This force brings the droplets closer, increasing in strength as the distance between the droplets decreases .…”