Optimization Design Of Industrial Microwave Heating Cavity And Leakage Suppression Structure

Microwave heating has the advantages of selective heating,high heating efficiency,easy control of heating process and fast heating speed,etc.,therefore,it is widely used in food heating,metallurgical engineering,chemical engineering,biopharmaceutical and other industrial production.The principle of microwave heating is based on the principle of electromagnetic loss,the heating material in the electromagnetic field contains polar molecules,polar molecules will change with the direction of the electric field polarity will reverse,because of the high frequency of microwave,make the polar direction of the polar molecules constantly,rapid change,and then produce heat,play the role of heating the material.The advantages of microwave heating in industrial heating are obvious,but the phenomenon of non-uniform heating is easy to appear in the process of microwave heating,and the problem of microwave leakage is easy to appear in the inlet and outlet of industrial microwave heating,therefore,in this paper,the problem of“Hot spot” and uneven heating and leakage wave of inlet and outlet in microwave heating are studied.1.In the process of optimizing the uniformity of microwave heating,it is a problem to measure the reference standard of the uniformity of microwave heating.2.A method of optimizing industrial microwave heating based on finite element method is proposed,and the microwave heating cavity is simulated by the Finite Element Method Software Comsol,the influence of different factors on the uniformity of microwave heating was studied from the cavity model,the position of heating carrier and the number of excitation sources.The uniformity of microwave heating is better than that of rectangular cavity,cylindrical cavity and trapezoid cavity by means of temperature variance and average temperature When the cavity is determined to be a cuboid,the better position of heating carrier is determined by comparison,and the uniformity under 21,19 and 15 sources is studied after the height is determined,it is found that the uniformity is better when the number of excitation sources is 15,and the power is saved.3.A photonic crystal model was constructed to solve the problem of microwave leakage from the inlet and outlet of the material,and the photonic crystal model was simulated by the Finite Element Software Comsol,the influence of different factors on the photonic bandgap is studied by changing the lattice constant and the radius of the dielectric cylinder.The lattice constant is 70 mm and the radius of the dielectric cylinder is 21 mm.In this case,the photonic crystal model can include the microwave heating frequency of 2450 MHz in the photonic bandgap.4.According to the parameters of photonic crystals,the leakage suppression devices of square photonic crystals and hexagonal photonic crystals are designed,and the above-mentioned leakage suppression devices are optimized and improved,in the design of photonic crystal leak-wave suppressor has a feed-in and feed-out port,through HFSS simulation of the feed-in and feed-out port,and the application of photonic crystal in the simulation,we found that the leakage of microwave has been greatly improved.