Abstract: Porosity is directly related to the change of the tortuosity of drying medium, massenergy conversion and airflow resistance, which is one of important parameters to analyze the drying process and drying energy consumption of rice. In order to accurately obtain the porosity parameters of rice layer in flowing state, this paper created the detection device of porosity in rice flowing layer, analyzed the measurement performance of the detection device and investigated the evolution law of the porosity of rice flowing layer under different working conditions combined with the orthogonal experimental method and the physical significance of parameters. The results showed that the porosity detection device of flowing layer had excellent reliability, and the variance range of multiple test results was 0.010 1-0.022 9. In the range of moisture content of 12.73%-32.01%, the porosity of rice flowing layer decreased with the increase of moisture content, the porosity in flowing layer showed a regular change of decreasing and then increasing in the range of 400-850 mm of rice flowing layer thickness, and its minimum value was 63.1%, within the range of 0-80 mm opening, the porosity of flowing layer increased with the increase of the opening.

Key words: rice, drying, flowing layer, porosity, detection device

摘要： 孔隙率直接关系到稻谷干燥介质迂曲度、能质传递、通风阻力的变化，是解析稻谷干燥过程和能耗的重要参数之一。为准确获取流动状态下稻谷层的孔隙率，设计稻谷流动层孔隙率检测装置；结合正交试验方法和参数的物理意义，分析检测装置的测量性能，并研究不同工况下稻谷流动层孔隙率的演变规律。结果显示，流动层孔隙率检测装置具有较好的可靠性，且多组试验结果的方差范围为0.010 1-0.022 9；在含水率为12.73%-32.01%区间，流动层孔隙率随稻谷含水率增大而逐渐减小；流动层孔隙率在稻谷流动层厚度为400-850mm范围内呈现先减小后增大的规律变化，且其最小值为63.1%；在开度为0-80mm区间内，流动层孔隙率随开度增大而升高。

关键词: 稻谷, 干燥, 流动层, 孔隙率, 检测装置