Structre Design And Electromagnetic Simulation Of A Microwave Drying Cavity

Compared with the traditional hot air drying,microwave drying has the advantages of high heating efficiency,energy saving,environmental protection and so on.At the same time,its unique heating characteristics and drying mechanism provide a variety of processing technology for material drying.Microwave,as a clean energy,completely meets the needs of the current society,its wide application range,affecting all aspects of human life.The production and development of microwave drying equipment greatly improve the industrial production efficiency and save a lot of labor costs.The arrival of the industrial 4.0 era means the automation and intelligence of the manufacturing industry,the research of microwave drying equipment is more perfect,and the effect of microwave drying is becoming higher and higher.Microwave drying cavity is the key structure of microwave drying system.During microwave drying,electromagnetic energy is continuously converted into heat energy and dissipated in materials.In order to improve the heat transfer efficiency of microwave energy and the uniformity of the distribution of the temperature field,the relationship between the distribution of the electromagnetic field and the structure of the microwave drying cavity must be studied so as to optimize the structure of the microwave drying cavity.To this end,the main work of this paper is as follows.1.The electric field model of microwave drying cavity is studied by using Maxwell equations,and the heat transfer model of microwave drying is established by Fourier theorem.The finite element method is used to study the numerical solution of the electromagnetic model of microwave heating and drying,and the linear interpolation function of the subdivision element is derived by using the variational method.2.In order to improve the uniformity of electromagnetic field and temperature field of microwave drying,the structure optimization of microwave drying cavity was studied.The finite element software COMSOL Multiphysics is used to simulate the structure of cavity field.The influence of the position of waveguide opening and the size of loaded medium on microwave heating efficiency is studied.Through the analysis of the electric field distribution and the maximum electric field intensity in the cavity,the optimization principles of the structure parameters such as the width,depth and height of the cavity are obtained.3.The design idea of microwave drying material system is put forward.According to the different kinds of materials needed,the feeding device,transmission device and lifting device are improved,and the independent control and disassembly of each device are realized.Through the combination of each control module and the reasonable selection of control system,the whole material drying system is continuous and automatic production is realized.4.Potato was used as microwave drying material and microwave drying experiment was carried out under different power.The mass transfer law of the heated potato was analyzed,the water loss rate and the temperature of the potato under different firepower were tested,the effect of microwave heating power on the water loss rate was obtained,and the correctness of the simulation was verified.