基于Weibull分布函数的龙眼果肉微波真空干燥模拟研究

为探索龙眼果肉微波真空干燥过程内部水分变化规律,采用Weibull分布函数建立龙眼干燥动力学模型,并对干燥动力学曲线进行拟合分析.干燥试验条件如下:微波功率为300、400、500W,真空度为280、230、180Pa.试验结果表明:Weibull分布函数拟合的龙眼果肉干燥曲线与试验曲线一致;尺度参数 α 随着微波功率...

Research and Modeling Microwave Vacuum Drying of Peeled Longan Based on Weibull Distribution Function

In order to investigate Peeled Longan’s moisture diffusion regulation and build the drying model.The Weibull distribution function was applied to the drying process under different levels of microwave power(300W,400W,500W)and vacuum pressure(280Pa,230Pa,180Pa)and the results were analyzed.The results demonstrated that the Weibull distribution function was good in simulating the process of microwave vacuum and compared with Fick’s second law.The scale parameter(α)was related to drying time and decreased as pressure increased.The shape parameter(β)was related to rate of the mass transfer at the beginning of drying,for the same drying method,drying parameters had little impact on the shape parameter(β).The moisture effective diffusivity of Peeled Longan were calculated to be in the range from 4.8846×10-8 m^2/s to 16.1217×10-8m^2/s;which increased with increasing of the microwave power and vacuum pressure.The activeation energy determined from Arrhenius equation was 8.1813,8.1892 and 9.021W/g for 280,230,180Pa,respectively.This research provides technique foundation for the use of Weibull distribution function in microwave vacuum drying of Peeled Longan.