Modeling of magnitude of the applied electric field intensity during electromagnetic processing of oil in water emulsions

Abstract

Electromagnetic processing of the oil in water emulsion is a coupled electric-thermal problem. If an emulsion sample is placed into a homogeneous time-harmonic electric field, the resulting spatial distribution of the electric field intensity magnitude and the corresponding power loss density are highly inhomogeneous. Therefore, an inhomogeneous temperature distribution in the emulsion sample can be expected as well. In a previous paper, the numerically computed temperature distribution, using a well-proven commercial simulation tool, in the whole virtual emulsion sample did not confirm this expectation and for the studied sets of parameters the temperature distribution was homogenous for the whole duration of the virtual electromagnetic processing of virtual emulsion sample. In this paper, the coupled electric-thermal problem is, due to the uniform temperature distribution in the whole virtual emulsion sample, considerably simplified. It is proposed to compute the electric field intensity magnitude by solving the electromagnetic problem without considering the heat transfer. The heating can be estimated using a simple calorimetric formula. Furthermore, it is shown here, that to a first approximation, even the simulation of the electric field distribution can be omitted and a mixing formula can be used instead. The analytical model derived here, utilizes the mixing formula and simple calorimetric formula and is capable to estimate magnitude of the applied electric field intensity and heating rate during electromagnetic processing of oil in water emulsions. The results of the analytical model agree very well with the results of the coupled electric-thermal numerical simulations.