Batch type microwave grain dryer and drying method

Abstract

The invention relates to a batch type microwave grain dryer and a drying method. The batch type microwave grain dryer is provided with a grain elevator, and a tempering bin, a drying chamber, a collecting chamber and a microwave heating device which are connected with each other are sequentially arranged from top to bottom, wherein the drying chamber is used for drying and dehumidifying grains, and the microwave heating device is used for microwave heating of grains; a discharging port at the upper end of the grain elevator is connected with the tempering bin, and a discharging port of the microwave heating device is connected with a feeding port at the lower end of the grain elevator. According to the batch type microwave grain dryer, the grain discharging speed, the microwave heating radiation frequency and the temperature and humidity of the drying chamber hot air are controlled according to grain temperature and grain moisture, so that variable temperature and variable frequency drying are realized, and the drying efficiency of the grain is effectively improved.

Description

technical field [0001] The invention relates to a batch type microwave grain dryer and a drying method. Background technique [0002] Microwave is a kind of electromagnetic wave, which is an electromagnetic wave with a frequency from 300MHz to 300GHz. Its direction and size change periodically with time, and it is a penetrating electromagnetic wave. It has the characteristics of high frequency, short wavelength and high frequency. Microwave heating utilizes the principle of dielectric loss. Since water is a substance that strongly absorbs microwaves, the loss factor of water is much larger than that of dry matter. In a strong microwave field, the moisture in the material to be heated will move violently with the absorption of microwave energy, and a large amount of heat energy will be generated due to the violent movement and high-speed collision, which will provide a large amount of heat energy required for the transpiration of water, making its temperature Rising rapidl...

AI Technical Summary

Problems solved by technology

The traditional microwave drying process is to pass the materials collectively through the drying chamber, and add a microwave heating device in the drying chamber for direct drying. Not only the microwave utilization rate is low, the drying efficiency is low, the structure matching is unreasonable, it is easy to cause local microwave radiation intensity, resulting in local temperature. If the drying temperature is too high, the risk of carbonization or fire will be formed. If the drying temperature is too high, the cracking rate of the grain will be increased, the drying quality of the grain will be reduced, and the nutritional content of the grain will be destroyed, which is not suitable for industrial applications.

[0003] The prior art most related to the present invention is the patent titled "A Grain Drying Device" (Patent No.: 201710035017.4). The microwave transmitting antenna is directly installed in the drying chamber. The ventilation area is small, and the grains are ventilated and dried immediately after microwave heating. The drying efficiency is low. The drying gas enters the drying room from the natural gas in the outdoor environment to ventilate and dry. The drying efficiency is greatly affected by the ambient temperature and humidity, especially in autumn and winter. Decreases sharply and does not dry properly

The above factors directly lead to low drying efficiency of grain, which is not suitable for industrial application

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