Research And Development Of Drying Technology And Equipment For Granite Plate Based On Microwave Energy

Granite plate is widely used in construction,decoration and other industries,because of its rich texture,gorgeous color and good physical and chemical properties.However,due to the presence of moisture and alkalinity of granite plate,the uneven change of the color of the plate surface will be caused,which will seriously affect the decorative effect of granite plate.In order to ensure the appearance stability of granite plate,it is necessary to dry and seal the granite plate.With the development of social economy,the consumption of granite slabs has increased year by year,and the requirements for their quality have continuously improved,resulting in the gradual popularization of drying and sealing processes in the industry.In the national "Fourteenth Five-Year Plan" and Outline of Vision and Objectives for 2035,the overall requirements for energy system construction and industrial green development have been clarified.Traditional drying processes such as hot air drying and natural air drying cannot meet future energy consumption or efficiency requirements.In the field of stone materials,there is an urgent need for an efficient and energy-saving granite plate drying process.Using the method of combining finite element simulation and experimental research,this paper takes granite plate as the research object and it analyzes the distribution of electromagnetic field,temperature field,and moisture within the granite plate during microwave drying,as well as the effects of microwave power,material thickness,and other parameters on the drying characteristics of granite plate,and then obtains the change rule of moisture ratio of granite plate during the drying process,The research focuses on the dynamic model of microwave drying of granite,the detection method of moisture content,and the development of a new prototype.A coupling model of electromagnetic-mass heat transfer is established,and the distribution of electromagnetism,temperature and moisture in the slate is obtained through finite element simulation.The simulation model is validated by combining the characteristics of temperature and moisture changes during stone drying with microwave drying experiments,which provides theoretical basis and technical support for the application of microwave energy to the stone industry.Through the key parameter test of microwave drying granite,the relationship between moisture content,moisture ratio,water loss rate,microwave power and heating time of granite plate is obtained,and the dynamic model of granite microwave drying is established to predict the change of moisture ratio of granite under different drying conditions,providing a basis for parameter optimization and intelligent control of equipment for microwave drying granite.Based on the machine vision technology,the correlation between the five image features of the gray histogram of the granite plate surface image,including mean value,variance,skewness,kurtosis and entropy,and the moisture content is analyzed,and the granite moisture content detection model is established to shorten the detection time.According to the market demand for granite plate drying equipment,a prototype design scheme was developed,and the development of a granite microwave drying equipment prototype was completed,and prototype performance tests were conducted to verify the rationality of the prototype design.The prototype includes auxiliary links such as a material transfer device,a drying process control system,a moisture content detection device,a microwave generation device,a protection device,and an exhaust and dehumidification device,which can achieve low energy consumption and high efficiency of granite plate drying.This dissertation applies microwave drying technology to the field of stone processing,providing a new process for stone drying,which will promote the green development and transformation and upgrading of stone processing industry.