With the improvement of the people's living standards, people are paying more and more attention to the quality of dried foods and put forward higher requirements for the quality of foods. As we all know, different drying techniques have a great influence on the quality of dried foods, and even play a decisive role. In China, traditional processing techniques such as hot-air drying are still dominant in the food production and processing industry. However, the products produced by this type of processing method have a large degree of damage to color, nutrient content, and other biologically active substances. To obtain good quality dry products often requires expensive methods and equipment such as freeze drying. Therefore, how to produce high-quality products at lower cost has become an urgent problem to be studied and solved in the current research of agricultural products and food drying, and it is also one of the biggest challenges in the research and development of drying technologies. This article describes the application of microwave vacuum drying technology to solve the problem of the development of the current drying field. Microwave vacuum drying Microwave vacuum drying is a new combined drying technology developed with microwave drying technology. It not only has the advantages of fast drying speed, low temperature, low material temperature, color, fragrance, and nutrient retention, but also the parameters can be controlled and it can dry many different types of materials. Although some units in our country are currently studying, their technical performance still needs to be improved, and there are still many problems in mechanism and technology that need to be deepened and studied. 1.1 Principle of Microwave Vacuum Drying 1.2 Microwave Vacuum Drying Features (1) High drying rate. In ordinary drying methods such as hot air drying, the heat is transferred from the surface to the inside of the material, and the moisture migrates from the inside outward. The temperature gradient is opposite to the direction of the moisture transfer, which will result in a decrease in the drying rate. Microwave drying is the use of microwave energy directly to the entire material, so that the entire material is heated evenly, greatly reducing the heating time; At the same time due to the existence of pressure migration dynamics, so that microwave drying has the characteristics of drying from the inside, to overcome the conventional drying In the middle, the outer layer of the material is first dried to form the drawback that the hard shell plated joint hinders the internal moisture from moving outwards, and the drying rate is high. (3) Low cost and no pollution. Microwave vacuum drying is adopted without electric heating equipment and steam heating equipment. The microwave directly interacts with the material without heating air, large area walls and conveying equipment. The heating cavity is a closed cavity made of metal and can reflect microwaves. Absorbed by the material, it will not leak out and will not cause environmental pollution. Its energy consumption is 1/3 to 1/4 of that of ordinary drying equipment, much lower than infrared drying. (4) High degree of automation. As long as the microwave power is controlled, immediate heating and termination can be achieved. The man-machine interface and PLC can be used for programmable automatic control of the heating process and heating process specification. The operation is flexible and simple, one-click setting, system automatic. Our company is a high-tech enterprise specializing in R&D, manufacturing and sales of industrial microwave energy system equipment. We have a backbone technical team that has been engaged in the research of microwave application technology for many years, and have accumulated a number of core technologies for microwave applications, especially in non-standard. Product design and development, with strong technical strength and protection. A warm welcome to all users to inquire, on-site inspections, visits and negotiations; we will be happy to provide you with quality services. Pp Plastic Yard Signs,Pp Corrugated Sale Signs,Corrugated Plastic Sale Sign,Pp Corrugated Plastic Yard Sale Signs Yixing Guanyu New Materials Co.,Ltd , https://www.plasticsheetsupply.com
Microwave heating is a process in which the object to be heated becomes a heating element without heat conduction. The electromagnetic wave passes through the material from the surrounding or a specific direction, so that each part of the material obtains heat energy at the same instant and rises in temperature. Therefore, uniform heating can be achieved in a short time. . At this time, due to evaporation of moisture on the surface of the material, the surface temperature decreases, resulting in a high temperature gradient inside and outside, the direction of this gradient coincides with the direction of moisture evaporation, so that evaporation is accelerated, so the efficiency is extremely high. At the same time, in the negative pressure vacuum environment, the boiling point of water is reduced, so that the material can be evaporated and dried at a lower temperature, and at the same time, the drying efficiency is improved. 
(2) Improve the drying quality. Microwave heating is uniform heating at the same time inside and outside of the material, the place with higher water absorption absorbs more radiant energy, relatively less dry matter, and can be dried more quickly, which has the effect of automatic balance of heat distribution; at the same time, vacuum drying can reduce water The evaporation temperature allows the material to quickly evaporate at a lower temperature, avoiding the phenomenon of burns, coking, crusting, and hardening caused by simple microwave heating due to overheating, and at the same time can avoid oxidation, thus improving the drying quality. Especially in the case of heat-sensitive materials in the fields of medicine, food, and chemical engineering, the conditions of low-temperature rapid drying are required. At the same time, for food and medicine, due to the biological effects of microwaves, sterilization can be achieved at a relatively low temperature.