中间水分大豆振动真空微波联合干燥过程的研究

Research on the drying process of intermediate moisture soybeans by vibration-vacuum and microwave combination

为了进一步研究中等含水率物料的干燥特性,解决传统干燥方法中物料干燥不均匀、品质下降严重等问题,将振动和真空单元与微波干燥相结合,比较了干燥过程中微波功率、装载量和振动频率对含水率的影响。综合考察了同等条件下热风干燥、传统微波干燥、微波振动干燥和微波真空振动干燥的干燥特性。结果表明:在真空度-0.065MPa以下,微波输出功率0.5～1.0W/g,传动电机转速350～550r/min的范围内,提高微波功率质量比、增加转速、优化装载量均有助于缩短干燥时间、提高干燥效率;振动-真空微波联合干燥与传统热风干燥相比能耗降低70%,与微波振动干燥相比爆腰率降低60%。在降低能耗量的同时保证了物料的干燥品质。

In the traditional drying process,problems such as uneven drying and sharply decline of the quality were usually inevitable.In order to make a further study on the drying characteristics of materials with intermediate moisture content,described a new drying approach to analyze the effect of microwave power,loadage of materials and vibration frequency on the moisture content.And the characteristics of hot-air drying,traditional microwave drying（MD）,microwave-vibration drying（MVD）and microwave-vacuum-vibration drying（MVVD）in the same conditions were investigated.The results showed that improving the ratio of microwave power versus mass,increasing vibration frequency and choosing a appropriate loadage helped to shorten the time and improve the efficiency of drying,with the condition of vacuum degree below-0.065MPa,output power 0.5 ~ 1.0W/g and vibration motor drive speed in range of 350 ~ 550r/min.Compared with traditional hot-air drying process,the MVVD had 70% reduction of energy consumption which could reduce 60% of crack rate than MVD process.This combination drying process ensured higher quality and cost less energy at the same time.