In this study we considered mass transfer under the influence of an alternating electric field in a ternary system comprising a solute, liquid dielectric continuous phase and a stationary fluid dielectric sphere. Solubility of solute in dispersed and continuous phases have the same order of magnitude and resistance to mass transfer in both phases is taken into account. The applied electric field causes Taylor circulation around the fluid sphere. Droplet deformation under the influence of the electric field is neglected. The problem is solved in the approximations of a thin concentration boundary layer in dispersed and continuous phases. The bulk of a droplet, beyond the diffusion boundary layer, is completely mixed, concentration of solute is homogeneous and time-dependent in the bulk, and the thermodynamic parameters of a system are constant. The system of transient coupled equations of convective diffusion for solute transport in dispersed and continuous phases with time-dependent velocity components and time-dependent boundary conditions is solved by combining a generalized similarity transformation method with the Duhamel's theorem, and the solution is obtained in the form of Volterra integral equation of the second kind for all frequencies of the applied electric field. The rates of mass transfer are calculated for direction of fluid motion from the equator to the poles. Numerical calculations show essential enhancement of the rate of mass transfer during extraction of organic acids from water droplet by benzonitrile under the influence of electric field for a stagnant droplet. Dependence of solute concentration in the bulk of a droplet from the frequency of the applied electric field is analyzed, and the asymptotics of the obtained solutions are discussed.
|Number of pages||8|
|Journal||Chemical Engineering and Processing: Process Intensification|
|State||Published - 1 Jul 2006|
- Electric field
- Mass transfer
- Taylor circulation