用Weibull函数分析单粒莲子热风干燥的水分扩散系数和活化能

Analysis of the moisture diffusion coefficients and activation energy of lotus seed hot air drying based on Weibull distribution function

为了研究单粒莲子在不同温度(50、60、70、80、90℃)条件下热风干燥的干燥特性、水分扩散系数及活化能,利用Weibull函数及经验模型对单粒莲子干燥过程进行模拟分析。结果表明:Weibull函数和Midilli模型可以很好地拟合单粒莲子的热风干燥过程;尺度参数α随干燥温度的升高而减小(p<0.05);干燥温度对形状参数β的影响较大(p<0.05);计算得到干燥过程中估算的水分扩散系数为(8.79×10^(-9)~2.45×10^(-8))m^2/s,水分有效扩散系数为(4.73×10^(-10)~1.31×10^(-9))m^2/s,活化能为22.61 kJ/mol,水分扩散系数随温度的升高而增大。该研究为Weibull分布函数应用于莲子干燥提供参考。

In this study, the kinetics of lotus seed hot air drying under different drying temperature（50, 60, 70, 80, 90 ℃） was investigated. The Weibull distribution function and empirical models were applied to simulate the drying process. The result demonstrated that the Weibull distribution function and Midilli model could fit the process of lotus seed hot air drying well. The scale parameter（α） was found to be related with the drying temperature（p0.05）, and its value decreased with increasing of drying temperature. The drying temperature had significant influence on the shape parameter（β）（p0.05）. The calculated moisture diffusion coefficient（Dcal） and moisture effective diffusion coefficient（Deff） of lotus seed were calculated to be in the range from（8.79×10^（-9）-2.45×10^（-8））m-2/s and from（4.73×10^（-10）-1.31×10^（-9））m-2/s, which increased with increasing of drying temperature. The activation energy for lotus seed hot air drying was 22.61 kJ/mol. The research will provide a reference for the application of Weibull distribution function on lotus seed drying.