Microwave drying method and device adopted by same

Abstract

The invention provides a microwave drying method. The microwave drying method comprises the following steps: placing a product to be dried in a sealing cavity of microwave drying equipment; performing microwave drying through the microwave drying equipment emitting microwaves and meanwhile performing forced convection on a gas in the sealing cavity; and monitoring the temperature of the gas in the sealing cavity and the surface temperature of the product to be dried, and at the same time performing post-treatment on the gas in the sealing cavity and enabling the gas after post-treatment to return to the sealing cavity in a cyclic manner. According to the microwave drying method and the device adopted by the same, the temperature and humidity of the gas medium in the sealing cavity are controlled on the basis of the conventional microwave drying technology, meanwhile the essence of the material drying principle is well utilized, so that the purpose of performing microwave drying by efficiently utilizing microwaves is achieved, and technological problems that materials are excessively dried, deformed, burned and denatured during the microwave drying process are effectively avoided; meanwhile, the microwave drying process is enhanced in an energy-saving manner through approaches such as complete moisture circulation and reutilization and cavity heat preservation. The invention further discloses the device adopted by the method, parts are easy to obtain, and the implementation is easy to realize.

Description

technical field [0001] The invention relates to the technical field of microwave drying, in particular to a microwave drying method and a device used therefor. Background technique [0002] The microwave drying method makes full use of the advantages of high microwave heating speed and high efficiency, greatly shortens the time required for drying products, and has a significant effect of energy saving and efficiency improvement. Microwave drying has been fully recognized in social production. [0003] Microwave drying is a method of internal heating, specifically: the wet material is placed in a microwave high-frequency electric field with a very short oscillation period, and the water molecules inside it will be polarized and arranged neatly along the direction of the microwave electric field, and then rapidly increase with the high temperature. Rotation due to alternating changes in the direction of the frequency alternating electric field, and violent collisions and fric...

AI Technical Summary

Problems solved by technology

The existing commercial microwave drying technology pays attention to the efficient heating effect of microwave on drying products, and ignores the surrounding low-temperature atmosphere when these materials are heated by microwaves. A large amount of heat energy from microwaves is transferred from materials to microwave drying through convection, radiation, conduction, etc. In the cold air in the cavity, the heating rate slows down and the microwave efficiency decreases

[0007] Secondly, the heat loss accompanying the existing microwave drying technology is too large

With the progress of the drying process, the air humidity in the microwave drying chamber gradually increases, and the temperature also gradually increases. The existing microwave drying process adopts the method of forced air extraction and dehumidification at regular intervals or when the humidity is higher than the threshold value, which carries a large amount of sensible heat and The hot and humid air with latent heat of water vapor is dehumidified and emptied, and the lost air is replenished externally. Although the purpose of dehumidification and water discharge can be achieved, the price is a large loss of hot air in the drying chamber and a sharp drop in temperature. The compensation for the lost heat will be directly Increase energy consumption and reduce the benefit of microwave drying process

[0008] Finally, the existing commercial microwave drying methods have not been able to connect with the original optimal drying process of materials, and cannot give full play to the characteristics of fast, efficient and efficient microwave drying. Changes can only be made by suppressing the contribution of microwave heating and reducing microwave input power. These will greatly reduce the efficiency of microwave drying and cannot "make the best use of everything".

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