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

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.