【作者】 张银；

【导师】 姬长英；

【作者基本信息】 南京农业大学 ， 农业机械化工程， 2004， 硕士

【摘要】 我国是农业大国，人口众多，由于经济的需要，耕地逐年在减少，粮食的生产也随之减少。而我国每年收获的粮食出于各种原因，损失相当惊人。因此，确保现有耕地所产粮食少受甚至不受损失，至关重要。有效的方法是普及粮食干燥机。随着干燥机的普及，面临着干燥机的使用问题。既要保证干燥后粮食的品质又要注意能源及产量不必要的损失。因此，干燥粮食时采用合理的工艺流程，选择合适的干燥参数，对保证粮食干燥后的品质具有重要意义。 本试验是在实际干燥生产中进行的，利用本单位的种子干燥机，在干燥过程中测取干燥参数，进行种子稻谷的干燥试验。旨在实际干燥过程中，通过不同的干燥条件，了解干燥过程各参数之间的关系，为今后的干燥工作提出指导意见。 试验结果表明稻谷含水率随干燥时间的延长而平稳降低，呈减速趋势。高水分稻谷在干燥前一段时间降水较大，呈等速趋势，含水率达一定值后，降水又呈减速趋势。干燥时间与含水率的关系近似线性关系，可用回归方程M=at+b来描述。 干燥过程中，稻谷经过一段预热升温时间后，达到某一值便不会随干燥时间的延长而升高，总在某一值上波动，且波动幅度很小。一般情况下，干燥温度高，稻谷温度也高。因此可用调整热风温度的方法来控制稻谷的温度。 谷物平均温度随热风温度的升高而逐渐增加；谷物的平均干燥速率随热风温度的提高而增大。 随着热风温度的提高，稻谷平均发芽率损失有比较明显的增大趋势。当谷物温度达到34℃以上时，种子发芽率损失明显增大。相同干燥条件下，所用干燥时间比较多的批次，其发芽率损失比所用干燥时间少的要低。干燥过程中，干燥速率越大，发芽率损失也越大；稻谷初始含水率越大，发芽率损失也越大；相同热风温度下，干燥数量越少，其谷物温度就越高，干燥速率就越大，发芽率损失也越大。 在实际干燥工作中设定合适的热风温度。在干燥过程中，根据干燥情况调整热风温度，在不影响稻谷品质的前提下，提高干燥机的工作效率，减少不必要的能源消耗。更多还原

【Abstract】 China is a big country with huge populations. The demand by economic development led to the decrease of farming land and thereby reduced crop yield year by year. On the other hand, annual grain loss due to various reasons is huge. Hence, it is acute importance to avoid the harvested grain loss. An effective measure is to extend grain drying machines. As drying machines are extended, the problem of drying machine operation appears. Attention not only should be paid on the quality of the dried grain, but also on economic energy consumption and reduced loss. Thus selection of reasonable drying technique and suitable drying parameters is an important guarantee for a better drying quality.The experiment was conducted during a real drying process. Using our own drying machine, we measured some drying parameters and experimented on the drying machines. The aim of this work is to learn the relationships between various parameters in drying procedure, so as to provide constructive opinion for the future improvement work.Results showed that grain water content steadily decrease with the time elapse, showing a decreasing trends. High water content grain lose water in a higher rate, having a steady rate, and when reaching a certain water content, turning into a decreased water losing rate. A linear relationship is noticed between drying time elapse and grain water content, a regression formula of M = at + b is suitable for expressing such a relationship.During the drying process, temperature of grain do not surge after an initial stage of pre-heating period, it fluctuates around a value but with a little degree. In general, higher drying temperature results into higher grain temperature. So that the control of grain temperature can be realized by the adjustment of the temperature of hot air.Average grain temperature increases as the temperature of the hot air increases, so is average drying rate.As the hot air temperature increases, the germinating rate is obviously impaired. When grain temperature is raised above 34C, seed germinating rate is clearly reduced. On the same drying conditions, the batch with longer drying period will have a lower germinating rate compared with the shorter drying period. A higher drying rate results into more reduced germinating rate. A higher initial water content relates to more reduced germinating rate. Onthe same hot air temperatures, reduced drying quantities relates to increased grain temperatures and higher drying rates, resulting into higher loss of germinating.In the drying process the hot air temperature should be properly adjusted. Depending on the drying conditions in the real practice, regulation of hot air temperature should be performed, so that no negative effect happens on paddy seed quality and the working efficiency of drying machine is increased, avoiding energy loss is reached.更多还原