Vegetable microwave dryer and method for precise control of material surface temperature

Abstract

The invention discloses a material-surface-temperature-accurate-control vegetable microwave dryer and method. A material conveying system, a heating moisture exhaust system, a control system and the like are included. The heating moisture exhaust system is fixed on the material conveying system. The heating moisture exhaust system comprises a waveguide part, a moisture exhaust fan, magnetrons, a plate type stirrer, a stirring motor and the like. The waveguide part is fixed on the machine frame. The magnetrons are fixed on the top of a box body of the waveguide part in two rows. A waveguide moisture exhaust opening is connected with a moisture exhaust fan inlet. The plate type stirrer is hinged into the waveguide part and is driven by the stirring motor to swing. Accordingly, microwaves in the waveguide part can be distributed evenly. An infrared thermal imager is fixed at the center of the upper portion of the box body of the waveguide part. Material surface temperature is transmitted to a computer in real time during a drying process. The computer controls microwave energy output of the magnetrons through a console according to material temperature and set temperature, accordingly, dried material temperature is controlled to be kept in a proper range all the time accurately during a drying process, and the drying quality of agricultural products is guaranteed.

Description

technical field [0001] The invention relates to agricultural product processing machinery, in particular to a vegetable microwave drying machine and method for precisely controlling the surface temperature of materials. Background technique [0002] Drying is one of the important means of agricultural product preservation. Dehydrated and dried agricultural products have the advantages of convenience, health, no need for refrigeration and low transportation costs, and have broad market prospects all over the world. At present, the drying methods mainly include hot air drying, vacuum drying, freeze drying and microwave drying, etc., but the commonly used hot air drying takes a long time and is slow, and forms a negative temperature gradient from the surface to the inside, which is not conducive to water evaporation. Dry the surface first. It will hinder the diffusion of internal moisture, and the drying quality cannot be guaranteed; the drying temperature of vacuum drying and ...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a microwave drying machine and method for vegetables with precise control of material surface temperature in order to overcome the shortcomings of ordinary microwave drying equipment, which are prone to overheating and local temperature is too high, resulting in a decrease in the flavor quality of agricultural products and loss of nutritional flavor.

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