Microwave heating principle:
The microwave is the highest frequency band in the radio wave, ranging from 300 MHz to 300 GHz (wavelength is 1 m-1 mm). When the microwave is radiated onto the object, the electromagnetic waves that are not reflected enter the inside of the object and interact with the molecules that constitute the object. For different substances, the microwave energy generates energy conversion such as thermal effect, biological effect and chemical effect, thereby generating heat. To achieve the purpose of heating and drying.
Microwave sterilization mechanism:
Microwave sterilization is the result of the combined effects of thermal and biological effects of electromagnetic fields. The eggs and cells in the material will also relax due to molecular polarization, and absorb microwave heating. The thermal effect of microwave on the cells will cause the protein to denature and die. The biological effect of microwave on the cells is that the microwave electric field changes the potential distribution of the cell membrane section and affects the cell membrane. The concentration of electrons and ions around them changes the permeability of the cell membrane. The cells are therefore malnourished, unable to normalize metabolism, disordered cell structure, and inhibited growth and development. In addition, nucleic acids (RNA) and deoxyribonucleic acid (DNA), which determine the normal growth of cells and stable genetic reproduction, are crimped macromolecules that are tightly linked by several hydrogen bonds. Strong enough microwaves can cause hydrogen bond relaxation, fragmentation and recombination. , thereby inducing genetic mutations or chromosomal aberrations. The biological effects of microwaves play a special role in conventional sterilization without sterilization.
Main features of microwave heating:
1, heating fast
Microwave heating causes the object to be heated to become a heating element, and does not require a heat conduction process. Therefore, even in the case of a material having poor thermal conductivity, the heating temperature can be reached in a very short time.
2, uniform heating
Regardless of the shape of each part of the object, microwave heating can evenly penetrate electromagnetic waves in the surface of the object to generate thermal energy. Therefore, the uniformity of heating inside and outside the object is basically the same.
3, energy efficient
There is almost no loss in the microwave heating process except for the temperature of the heated material. Therefore, the thermal efficiency is high and energy is saved.
4, anti-enzyme, sterilization, preservation
Microwave heating has thermal and biological effects, and can be sterilized and protected against enzymes at lower temperatures. Due to the fast heating speed and short time, the activity of the material and the color and nutrients of the original material can be preserved to the utmost.
5, advanced technology can achieve automatic control
As long as the microwave power is controlled, immediate heating and termination can be achieved without thermal inertia. Application of human-machine interface and PLC can be used for programmable control automation control of heating process and heating process specification.
6, safe and harmless, improve working conditions
Since the microwave is controlled to work in the heating cavity and the waveguide made of metal, there is almost no microwave leakage, no radioactive residuals and harmful gas emissions, and the device has less heat dissipation and less noise, which greatly improves the working environment and labor intensity of workers.