The Research On Influence Law Of Microwave Frequency Effect On Demulsification

Using microwave to radiate emulsion, can promote the separation of oil and water. As an important parameter of microwave, frequency have a significantly influence to microwave treatment experiment. This paper studied the influence of microwave frequency on demulsification from the experiment and theory, it has important significance to the application of the technology in the field.Firstly, according to the need of experiment, design and process a microwave coaxial resonant cavity, then carry out microwave demulsification experiments by different microwave parameters (power, time and frequency), through measuring the amount of dehydration by different time, observe the influence of demulsification and dehydration, studied the influence of the microwave parameters on demulsification of emulsions. The second step is to establish mathematical models about the distribution of temperature field based on the emulsion theory establishes、electromagnetic field theory and the theory of heat transfer; then determine the mathematical model the relevant parameters, combine with the Maple software to solve the model. The third step according to the results of the experiments and mathematical model, the influence of the interfacial film shear viscosity、interfacial adsorption capacity the interface membrane shear viscosity and the bulk viscosity by the microwave frequency are discussed respectively, analysy the influence law of microwave frequency effect on demulsification, finally concluded the microwave breaking of emulsion mechanism.By theoretical and experimental study, the temperature distribution of emulsion Is proportional to the microwave irradiation time and to the square of the electric field strength.For the W/O type emulsion, in the applied electric field and microwave radiation frequency of certain circumstances, along with the increase of irradiation time, emulsion temperature linearly rising; microwave processing n the same time, emulsion temperature with applied electric field strength increases while the growth trend of parabola, namely the external electric field strength is greater, the more heat energy conversion of the dielectric loss, the temperature get higher; in the range of 235MHz-2450MHz, W/O type emulsion demulsification effect increasingly obvious with the increase of frequency. The reason for this phenomenon caused by the microwave radiation is the longer, the greater of the electric field intensity, the faster the temperature rises, the smaller the intermolecular attraction, thus making the surface tension decreased more significantly, interfacial molecular ordering began to loose, resulting mechanical strength of the interfacial film reduced and the inter-droplet coalescence, polyethylene, and the resistance decreased, promoting breaking of emulsion.