Passed the ISO9001 quality system certification and the establishment of industrial drying industry alliance standards under the guidance of the Chinese Standardization Research Institute.
- May 06, 2019 -
The frequency of microwave dryer is also very high in the food industry. Although it costs more than drying equipment, it is superior to other drying equipment in terms of heating speed, efficiency, operation mode and environmental protection. So, why is the heating speed and efficiency of microwave dryer higher than other equipment? In fact, it mainly comes from these three different types of heaters. The dried materials of waveguide heater of microwave dryer are dried by electromagnetic wave directed by waveguide tube. There are slots or holes in the waveguide to concentrate microwave radiation. Microwave is input from one end of the waveguide heater and an absorber for absorbing excess energy is installed at the other end. Microwave is transmitted from one end to the other without reflection in the waveguide, which constitutes a traveling wave field. The dried material passes through the waveguide tube and is heated uniformly and dried. There are many kinds of waveguide heaters in traveling wave field, such as tortuous waveguide heater, straight waveguide heater, bow waveguide heater, V waveguide heater, etc. The radiation heater of microwave dryer is equipped with horn antenna near the drying area, which is also called antenna type or horn type radiation heater. Material is placed under the horn antenna. Microwave energy radiates directly to the dried material and penetrates into the material. This heating method is the simplest and easy to realize continuous production. In order to improve the drying efficiency, slow-wave heaters, such as helical slow-wave heaters, must be applied in a short time when the surface of the dried material is large or the material itself is not easy to heat, or when the heat dissipation is fast. The microwave moves along the helix, which reduces the axial velocity and increases the electric field strength. When the material passes through the axis of the helix, it exchanges energy with the microwave and is heated. There are not only three kinds of heaters in microwave dryer, but also other kinds of heaters. They are based on the materials to be dried, including their properties, types, shapes and so on, to analyze specifically the microwave dryer and the types of heaters to be used.
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