Study Of A Resonator Based On The Microwave Sterilization

Microwave sterilization has the advantages of a short time, speed, uniform andthorough, high efficiency, pollution-free treatment, etc. Therefore it is increasingattention has been paid. Bactericidal effect of microwave on biological is mainly tothermal effect and non-thermal effect. In the past half a century, people put most of theenergy in the research on microwave heating effect, at present this aspect research andapplication has been basically perfect. In recent years, with the in-depth study of themechanism of microwave sterilization, non-thermal effect of microwave has been paidmore and more attention. Paraffin oil as a lubricant used in medicine, if sterilizationfailed, it is easy to cause a variety of infections. Conventional dry heat sterilizationmethod takes very long and poor texture after sterilization, vulnerable to the impact ofequipment performance, temperature and other factors.This paper is designed a resonant cavity which can be used for the sterilization ofparaffin oil based on the non-thermal effects of microwave sterilization. Firstexpounded the basic principles of microwave sterilization and microwave researchstatus of the non-thermal effects, also describes the resonator which currently widelyused for microwave sterilization, and specific analysis of several common resonatorstructure and the electromagnetic field distribution. My main work includes thefollowing aspects:1、The structural design of a resonant cavity for microwave sterilization. Firststarting from the electromagnetic distribution of the resonant cavity, according to thetheory of non-thermal effects, the resonant cavity should meet the electric field strengthcan reach about MV/m in its internal fixation area when the input power has hectowattmiddleweight. By comparing several typical characteristics of cavity, capacitive loadcoaxial resonator electromagnetic distribution to meet the requirements; then use of theknowledge of microwave circuit design and electromagnetic field theory for thecapacitive load coaxial resonator structure design analysis, including the size of themain structure, selection of materials and the selection of incentives, etc.2、The simulation and testing of the capacitive load coaxial cavity. According to the size of the above calculated, created a model of the cavity by the three-dimensionalelectromagnetic simulation software, through adjusting and optimizing, we get thestructure size and electromagnetic field distribution of the resonant with the frequency2.45GHz. The prototype is manufactured and tested, the results show that test results isconsistent with the simulation.3、Capacitive load resonant cavity used for microwave sterilization experiments.Magnetron as the microwave source, paraffin oil as a treatment liquid, E. coli asexperimental bacteria, plate count method to calculate the sterilization rate, before andafter microstructures of E. coli cells were observed by SEM. The results showed thatwhen the input power in the one hundred watts, the average sterilization rate above60%,no significant change in the surface structure of treated bacteria.