Research On Cavity-stabilized Microwave Chemical Reactors

In recent years,with the rapid development of the microwave chemical industry,the deep research on the microwave chemical reaction systems with various demands has received increasing attention.The role of microwaves on the material is not only reflected in the heating effect,but also in some more important non-thermal effects,these non-thermal effects often have a huge impact on the reaction.Reasonably designed microwave chemical reactors have reliable stability and can efficiently use electromagnetic energy.This thesis focuses on the reaction of microwaves with small amounts of substances at the laboratory level.From the perspective of electronics,a cavity-stabilized microwave chemical reaction system with some tuning capabilities was studied and designed with the center frequency at 2450 MHz.This article mainly elaborated the process of the subject research.Through theoretical calculation,simulation analysis and experimental testing,the process from idea to design and finally to verification was completed step by step.Firstly,the basis of microwave chemical reaction system and cavity size design is given theoretically,and the field structure of rare fan cavity is deduced.We used HFSS,ADS,SolidWorks and some other software to aid to design the cavity and system,and proposed a new and practical system structure by theory,which avoided the mismatch effect due to different materials insert.The characteristics of the field structure and cavity wall current of the TE₀₁₁ mode has been analyzed,and a variety of interference mode purification technologies have been proposed innovatively to achieve single-mode operation of the resonant cavity.Secondly,the cavity height was adjusted by a mechanical motor to change the resonance frequency of the cavity,achieving a tuning range of 2.2GHz to 2.6GHz.In the system design,the entire microwave chemical reaction system is built by connecting the resonant cavity with RF power amplifiers,phase shifters,attenuators,and coaxial lines.We have found that the coupling loop in the resonator has a great influence on the transfer function of the system.A reasonable size can ensure the system operate normally.Then,test the physical object with a test instrument such as vector network analyzer and spectrum analyzer.TheS₂₁amplitude-frequency curve of the resonant cavity and the signal spectrum of the microwave chemical reaction system are tested when the cavity heights are 80mm,92mm,100mm,110m,and 120mm,respectively.Compare these test results with the theoretically calculated and analyze it for the error.Finally,this thesis also expounds some deficiencies in the project and the work that can be further studied in the future.In practical applications,the microwave chemical reactor design of this subject has been found to have good stability,robustness and flexibility.It is the important part that uses some mode purification technology to achieve single-mode operation,which has the certain capability of tuning.At the same time,a new framework was proposed for the microwave chemical reaction system,which provided a certain guiding significance for the system design.Also,the author tries to explain various phenomena in the experimental design process.According to the design idea of this thesis,it can be designed as needed for various operating frequency points,larger working bandwidths,and higher power reaction systems.