哈密瓜片气体射流冲击干燥特性和干燥模型

    Air impingement drying characteristics and drying model of Hami melon flake

    • 摘要: 为了提高哈密瓜制干品质、缩短干燥时间,该文将气体射流冲击干燥技术应用于哈密瓜片的干燥,研究了其在不同干燥温度(60、65、70、75和80℃)和风速(5、10、15和20 m/s)下的干燥曲线、水分有效扩散系数以及干燥活化能,并建立了气体射流冲击干燥哈密瓜片的数学模型。研究结果表明:哈密瓜片的整个干燥过程属于降速干燥,水分有效扩散系数在2.38~4.55×10-9 m2/s的范围内随着干燥温度和风速的升高而升高;通过阿伦尼乌斯公式计算出了哈密瓜片的干燥活化能为29.44 kJ/mol。通过决定系数R2、均方误差的根(RMSE)和卡方检验值(2)等拟合优度评价指标对各种干燥模型进行评价,结果表明:Modified Page模型能很好的预测哈密瓜片气体射流冲击干燥过程中的水分比变化规律。该研究为使用气体射流冲击技术工业化干燥哈密瓜提供了技术依据。

       

      Abstract: In this paper air impingement drying technology was applied to drying Hami melon to improve the drying quality and decrease the drying time. The drying curves, moisture effective diffusivity and the activation energy of Hami melon drying were investigated under different drying temperatures (60、65、70、75 and 80℃) and air velocities (5、10、15 and 20 m/s). The mathematical model of air impingement drying Hami melon flake was obtained. The Fick’s second law of diffusion was used to calculate the moisture effective diffusivity, which increased from 2.38×10-9 to 4.55×10-9 m2/s with increasing the drying temperature and air velocity. The activation energy was 29.44 kJ/mol, which was determined from Arrhenius equation. According to the statistical parameters as the correlation coefficient(R2)、root mean square error(RMSE) and 2 , the modified Page model was best for predicting the moisture ratio change kinetics of Hami melon flakes during its drying process. The research can provide technical basis for industrial drying of Hami melon by air impingement drying technology.

       

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