Microwave is electromagnetic waves which frequency from 300 MHZ to 300000 MHZ. Water molecule of heating medium material is polar molecule, its polarity orientation of the electric field with changes caused by the movement of molecules under high rapid frequency electromagnetic field changes, cause the numerator movement and the friction effect of each othe. Microwave field can field at this time into medium heat, make temperature of material increase, produce and popped a series of materialization process to reach the purpose of microwave heating dry.

Microwave heating features:

1, Fast heating. Microwave heating is completely different with traditional heating mode. It makes heating medium become heater, do not need heat transfer process. Although thermal conductivity is poor materials, also can achieve heating temperature in a very short time.
 
2, Save energy and efficiency. Because materials contain water absorb microwave easily and fever, so in addition to a small amount of transmission loss outside, almost no other loss, so high thermal efficiency, save energy.
 
3, Heating even. No matter how shape of each part of the body, microwave heating all can make the object and evenly infiltration and electromagnetic wave list to produce the heat. So heating good uniformity, won't appear the endogenous phenomenon focal.
 
4, Mouldproof, sterilization, fresh. Microwave heating has thermal and biological effect, can sterilize and mould proof in low temperature. Due to heating rapidly, the time is short, can maximum limit save material activity and the vitamin original colour and lustre and nutrition of food.
 
5, Craft is advanced, control easily. Microwave heating just have the basic conditions of water, electricity, as long as control power, can realize microwave heating or terminate immediately, use microwave equipment can process automation control of heating process and heating process specification.
6, Covers less area, safety and harmless. Because microwave can be controlled in made of metal heating indoor and wave, so microwave leak is few, no radiation hazards and harmful gases, do not produce the waste heat and dust pollution; Neither polluting food, also do not pollute the environment.

From the economic efficiency analysis, microwave drying also have advantages than traditional methods , such as compared with the far infrared drying, usually save energy more than a third.
In actual work,microwave dry and sterilization equipment basically use in material with low moisture  (moisture content below 30%). Also can be used for high moisture.At this time, traditional drying method (hot air, electric oven d )drying rate low, consume energy , and tunnel type microwave drying equipment from start to finish drying ,need three to five minutes. Traditional methods, equipment, covering a large area, many employees, often have the pollution, fire control, etc.
 
Microwave sterilization principles:
Microwave sterilization is the extension of microwave heating technology function, performance for microwave and biology and its composition, the basic unit interact between cells, The cell biology physiological activities change and reaction, compare with pasteurization, microwave sterilization has the following characteristics:
A, Microwave sterilization is a physical sterilization method, it does not need to add chemical preservatives, can kill bacteria, mould and worm eggs, and virus harmful microbes, in the process of kill harmful organisms, will not residue toxicology or radioactive materials on food, safety and harmless, also won't change food color and nutrition.
B,Under same temperature sterilization, sterilization time is short, do not need to preheating. Such as e. coli kill time about 30 S. In the same sterilization condition, the temperature of the deadly bacteria is lower, and the sterilization effects are remarkably.
 
C, Can sterilize whole sterilization for material outside and inside at the same time, greatly shorten the sterilization cycle, and ensure the sterilization consistency.
 
D, Due to simultaneity of each part of material's sterilization, sterilization time is short, can avoid the long time heating and effect food good quality, especially for food that aren't suitable for sterilizing in high temperature or a long heating time. For example: volatile sweet essien components of ginger powder, contains more moisture of fresh and tender jellyfish, etc. For not only keeping for color, smell, taste and same quality requirements, etc,but also for material the need sterilize, using microwave sterilization can achieve the best effect.
 
E, Microwave sterilization can be divided into sterilizing before packaging and after packaging . Packaging container can't use metal material, need medium material, generally with plastic flexible packaging or glass, engineering plastic containers texture is advisable. To prevent from package expanding in microwave sterilization process, Equipment can be in work pressure in the warehouse by reverse pressure sterilization process to prevent the loss of package expanding.
 
Microwave equipment can sterilize different kinds of products with package and non-package, can be used for:
Food products categories: bread, moon cake, noodles, bean curd, bean curd, etc.
Vegetables: kimchi, bamboo shoot, mushroom, etc.
Fruit class: litchi, longan, etc.
Dairy products, spices, flavor, instant noodle soup, chafing dish, and all kinds of liquid, etc,can be sterilize processing.