低真空微波干燥技术研究

Investigation on Microwave Drying Technology in Low-Vacuum

低真空微波干燥结合真空干燥和微波干燥的优点,可大幅缩短干燥时间,但传统低真空微波干燥过程中易出现干燥不均匀和烤焦的现象,影响了应用。针对食品的低真空微波干燥过程进行了实验,分析了样品形状及干燥过程中微波对干燥效果的影响,并研究了微波干燥效率。实验结果表明,采用旋转天线可克服传统真空腔体无法实现微波调控易烤焦的问题;当食品含水量较大时,采用大功率微波可有效提高干燥效率;当食品含水量较小时,应调小微波功率或关闭微波,避免食品烤焦。

Low-vacuum microwave drying combines the advantages of both vacuum drying and microwave drying,which can greatly shorten the drying time.However,the traditional low vacuum microwave drying process is prone to uneven drying and scorching,which affects its applications.In this paper,the low-vacuum microwave drying process of food is investigated.The influences of sample shape and microwave on the drying effect,during the drying process and the microwave drying efficiency,are analyzed.The experimental results show that the use of a rotating antenna can overcome the problem that the traditional vacuum chamber cannot achieve microwave control and make food easy to scorch.When the water content of food is large,the drying efficiency can be effectively improved by using high-power microwave.On the contrary,the power should be reduced or the microwave should be turned off to avoid scorching the food.