一种微波功率可调的热风微波耦合干燥装置

摘要

In order to solve the existing problem of the system of coupled hot air and microwave drying , microwave power is controlled by the time intermittent .The instantaneous power of magnetron works constantly , by the way of adjusting the on-off time of magnetron to achieve an average output power of microwave .This approach can not change the instantane-ous power of magnetron and the output power of microwave is inaccurate , this lead to great damage on the quality of mate-rials.This research designed a system of coupled hot air and microwave drying ,the author achieved a way of continuous controllable of microwave power by adjusting high-pressure circuit capacitance to change the impedance anode circuit . The potato slices are used as the samples of the contrast experiment at the temperature of hot air 60 °C and different ca-pacitance value(0 mF ,0.25 mF ,0.33 mF, 0.5 mF, 1 mF).The results show that the drying efficiency of coupled hot air and microwave drying is better than hot air only, the speed is higher and the consumption is lower.The coupled hot air and microwave drying is a drying way which is fast , efficient and energy-saving , there will be more application in ag-ricultural production and food drying field .%现有的微波发出功率多采用时间间断式控制，磁控管的发射功率恒定，通过改变磁控管的通断时间实现微波平均输出功率的调节，这种方式不能改变微波的瞬间功率，微波功率输出控制不精确，对物料品质影响较大。为此，设计了一种微波耦合干燥装置，通过改变磁控管高压回路的电容，使磁控管高压回路的阻抗发生改变，以达到微波发出功率的线性可调。以马铃薯为试验研究对象，在热风温度为60°C、电容值魏0、0．25、0．33、0．5、1 mF）的条件下进行干燥对比试验，试验结果表明：热风微波耦合的干燥效率明显优于单一热风干燥，速度快、能耗低。热风微波耦合干燥是一种快速，高效和节能的干燥方式，在农产品和食品干燥中具有广阔的应用前景。