Research On Key Technologies Of Microwave Vacuum Drying And The Design Of Its Drying Machine For Cheese

Microwave heating,the technology that using high-frequency electromagnetic waves to trigger molecular motion to heat the materials,enjoys the advantages of fast heating speed,high drying efficiency and easy temperature control advantages.In addition,in the vacuum condition,because of the reduced boiling point of water,the moisture in the materials is easier to evaporate.People created new microwave vacuum drying technology based on the microwave and the vacuum technology.In the vacuum and low temperature environment,microwave vacuum drying uses microwave heating technology in a relatively short period of time to finish the material drying process.It has the advantages of high efficiency,energy saving,easy controlling and so on.In this thesis,we designed and developed the microwave vacuum drying experimental prototype for the cheese.Analyzed the influence of the microwave vacuum drying parameters on the drying characteristics of the cheese,and summarized the results to improve the drying efficiency and quality.The main research works are as follows:(1)On the basis of analyzing the heating principle,heat transfer mechanism of vacuum drying technology and microwave drying technology,the microwave vacuum drying experimental prototype is designed,including the design and development of microwave systems,the use of ANSYS HFSS in completing microwave uniformity design,the design of vacuum system,vacuum pump selection and design of pipeline.(2)Finished the determination of main performance of microwave vacuum drying experimental prototype,and checked the electric field intensity of the prototype.According to the working condition of the prototype,in order to solve the practical problems,the optimization of the vacuum system of the prototype is completed.Finish the development of microwave vacuum experimental equipment operating specifications.(3)Experimental Study on Microwave Vacuum Drying for Cheese.Drying cheese experiment is completed.The influence of the diameter of cheese on drying rate and drying temperature in the process of microwave vacuum drying is analyzed.Besides,analyze the change tendency of drying temperature according to the drying temperature-percentage of moisture curve.Then complete the analysis of various factors cheese test.(4)Comparison of microwave vacuum drying and conventional drying technology.Analyzed the economic benefit of microwave vacuum drying technology,and compared the microwave vacuum drying with the traditional drying technology in the drying effect,equipment maintenance and other characteristics to discuss the application of microwave vacuum drying.