微波红外振动床协同干燥机设计与试验

Design and Experiment of Microwave Infrared Vibrating-bed Dryer

针对农产品加工中微波干燥不均和红外干燥穿透能力有限等技术问题,研制了微波红外振动床协同干燥(MIVBD)设备。在结构设计上,通过COMSOL仿真分析谐振腔场强分布的均匀性,并优化了微波源馈波口布置。设备通过多孔面板将红外源与微波谐振腔隔离,在保证红外热量高效辐射的同时,确保微波、红外二者互不干扰。振动系统采用聚苯硫醚等谐振腔内部材料和钢结构外部材料制成,通过振动电机和橡胶弹簧带动物料振动。以高含水率生姜片为典型物料,对MIVBD设备的干燥效率、均匀性和色泽等相关品质进行试验研究,当物料温度超过上限温度时微波和红外停止工作,结果发现,微波红外振动干燥比微波红外干燥时间缩短了14.29%,微波红外振动干燥时温度不均匀系数最小(2.28%),并且微波红外振动干燥显著降低了干燥能耗,改善了相关品质。

In order to solve the problems of uneven drying during microwave drying and limited penetration during infrared drying for agricultural products, a microwave infrared vibrating-bed dryer(MIVBD) was developed. In the structure design, the uniformity of the microwave distribution in the resonator was analyzed by COMSOL, and the arrangement of the microwave source was optimized. The infrared source was isolated from the microwave resonator through the porous panel, which ensured the high efficiency of infrared heat radiation and the non-interference of microwave and infrared. The vibration system was made from polyphenylene sulfide(PPS) and other materials inside the resonant cavity, steel structure materials outside the resonant cavity, and agricultural products vibrate through vibration motor and rubber spring. Fresh ginger slices were selected as experimental materials. The drying efficiency, uniformity, and color of MIVBD were studied. When the material temperature exceeded 60℃, microwave and infrared stopped working. The results showed that the drying efficiency of MIVBD was improved by 14.29%. Infrared radiation and vibration can significantly improve the uniformity of material surface temperature distribution. The temperature uniformity of MIVBD was the best, and its temperature non-uniformity coefficient was 2.28%. The MIVBD significantly reduced the drying energy consumption and improved the related quality. The research result can provide theoretical basis and technical support for the application of microwave and infrared radiation in fruit and vegetable drying.