稻谷含水率分布及变化规律

利用计算机和单粒水分测定装置，测定稻谷干燥、缓苏、混合过程中稻谷的含水率分布，研究了稻谷与稻谷、稻谷与介质之间的水分交换机理和宏观运动规律。结果表明，在干燥初始阶段，如果谷层较厚或风量较小，高湿稻谷含水率偏差可能会随着干燥过程的进行而有增大的趋势，但最终的稻谷含水率趋向一致，加大风量可以提高干燥的均匀性；干湿稻谷混合后，稻谷含水率偏差随着混合时间的增加，按指数规律减小，稻谷的平均含水率越低，混合后的含水率偏差就越小。

Distribution and Variation of Rice Kernel Moisture Content

It is necessary to establish a drying method that takes moisture content (MC) of a single grain into consideration. The change of individual MC distribution in a rice kernel was investigated during drying, tempering and storing by using a computer and single kernel tester. The mechanism of moisture transfer between kernels, as well as between kernel and the media were discussed. The MC standard deviations decrease during the course of drying; while it will increase if drying at a high temperature and high humidity of air, usually occurred in the initial drying period because of small air-grain ratio. A large air flux will improve drying uniformity. Mixing of dry and wet grains makes the MC standard deviations of their mixture minish continuously as exponential form. The lower the average moisture content of rough rice is, the smaller the MC standard deviation is in the end of mixing. There is plenty of free moisture in hulls in initial period of moisture transfer among kernels. Ventilation can make grain surface moisture wipe off quickly and uniformly.