猕猴桃切片流化床干燥特性与干燥动力学模型研究

Study on drying characteristics and drying kinetic model of kiwi fruit slices in fluidized bed

为了提高猕猴桃切片制干品质、缩短干燥时间,采用流化床干燥技术对其进行干燥,研究温度(55,65,75,85℃)、风速(1.5,2.5,3.5,4.5m/s)和厚度(5,10,15mm)对猕猴桃切片热风干燥曲线、水分有效扩散系数以及干燥活化能的影响。结果表明:猕猴桃切片的整个干燥过程属于降速干燥,水分有效扩散系数为1.29639×10^(-9)~4.58994×10^(-9) m^(2)/s,且随温度、风速的增大而升高,随切片厚度的减少而增大;猕猴桃切片活化能为23.03kJ/mol。对10种常见的干燥动力学模型进行拟合发现,Logarithmic模型效果最佳。

In order to improve the drying quality and shorten the drying time of kiwifruit slices,the effects were studied in different temperatures(55,65,75,85℃),wind speed(1.5,2.5,3.5,4.5 m/s)and thickness(5,10,15 mm)on the hot air drying curve,water effective diffusion coefficient and drying activation energy of kiwifruit slices.The results showed that the whole drying process of kiwifruit slices belonged to reduced-speed drying,and the effective water diffusion coefficient was1.29639×10^(-9)~4.58994×10^(-9) m^(2)/s,which increased with the increase of temperature and wind speed,and decreased with the decrease of slice thickness.The activation energy of kiwifruit slices was 23.03 kJ/mol.After fitting 10 common drying kinetic models,it is found that the Logarithmic model is the best model.