In this work, the diffusion of moisture in the drying process of soybean grains is mathematical modeled considering shrinkage. Moisture and radius data as a function of time were obtained by experimental tests in a drying oven for three different drying temperatures. Radius decrease was registered by image analysis. The parameters of the diffusion model were obtained by nonlinear regression. The model provided diffusivity values and drying constants at the surface of the grains as a function of temperature. The average moisture profiles presented good agreement with the experimental values. Although the radius profiles predictions presented higher deviation when compared with the experimental values, a good agreement were found, especially at the higher drying rates of the process. The model provided good predictions of the moisture and radius profile for the drying process of soybean grains and the diffusivities and drying constants for considering the grain shrinkage during the process.

中文翻译：

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大豆干燥作为移动边界问题：收缩和水分动力学预测

在这项工作中，考虑了收缩，对大豆谷物干燥过程中水分的扩散进行了数学建模。在三个不同的干燥温度下，通过在烘箱中进行实验测试，获得了随时间变化的水分和半径数据。通过图像分析记录半径减小。通过非线性回归获得扩散模型的参数。该模型提供了作为温度函数的晶粒表面的扩散率值和干燥常数。平均湿度曲线与实验值吻合良好。尽管与实验值相比，半径轮廓预测显示出更高的偏差，但是发现了很好的一致性，尤其是在该过程的较高干燥速率下。