5HP-25型粮食干燥机设计与试验  

Design and experimental study of 5HP-25 type grain dryer

作　　者：骆恒光 李长友[1] 张永博 Luo Hengguang;Li Changyou;Zhang Yongbo(Key Laboratory of Key Technology on Agricultural Machine and Equipment,Ministry of Education,South China Agricultural University,Guangzhou 510642,China)

机构地区：[1]华南农业大学南方农业机械与装备关键技术教育部重点实验室,广州510642

出　　处：《农业工程学报》2021年第1期279-289,共11页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金(31671783,31371871);广东省科技计划项目(2014B020207001)。

摘　　要：为了提高干燥系统的能量利用效率,增强干燥机的通用性、可靠性、作业效率和年利用率,该研究围绕增大干燥动力系数和工艺能力指数,基于粮食的物性特征,从干燥工艺方式、机械结构参数和运动参数间的内在关系入手,把几何因子和运动参数有机结合,揭示了粮食在干燥机内流动特性;按照引风降压,连续闪蒸降温,强化传热传质,自适应排粮的设计思想,研制了一款粮食通用的干燥机,实现了粮食在干燥机内连续流动过程中,自发地改变流态、连续回转换位,强化了传热传质,改善了干燥的均匀性。设计的升角为6°的变截面角状盒,与传统的横流方法相比,可使干燥动力系数增大2~4倍,干燥稻谷时的爆腰增率可控制在1%以内,发芽势提高76%以上,发芽率达到95%;设计往复式差速排粮机构,实现了自适应无损排粮,有效解决了粮食架桥、堵塞问题,避免了粮种的机械损伤。设计的5HP-25型粮食干燥机,实际应用效果显示,在粮食平均干燥强度为1.37~2.70%/h的条件下,干燥水分单位热耗为2900~4300kJ/kg,与国标7400 kJ/kg相比,降低了单位热耗量。研究结果为实现优质、高效、节能干燥工艺及装备设计提供了参考。This study aims to enhance the operating efficiency and annual utilization rate in the mechanized drying of grains.Meanwhile,their versatility and reliability need to be improved.In order to strengthen the drying process,it is necessary to increase the dynamic coefficient,rather than the processing power only.A systematic investigation was made on the relationship between the geometric structural parameters and the motion parameters,in order to increase the drying dynamic coefficient for the non-destructive drying.The effects of geometric factors on grain flow characteristics were revealed using the combined geometric structure factors and motion parameters.Since the downward flow of grains depended mainly on the gravity of grains,the geometric structural parameters were used to express the natural flow state in the drying chamber.In addition,the flow speed of grain at a certain position was proportional to the speed of grain discharge.In the continuous flow process,there was an equal amount of absolutely dry matter flowing through any cross section in the drying chamber at any time,where the velocity ratio was equal to the inverse area ratio.A general-purpose grain dryer was developed,where the induced air was used to reduce pressure,while the partial flash evaporation was used to decrease the grain temperature,and a self-adaptive differential reciprocating grain discharging device was designed to strengthen the heat and mass transfer in the drying section.The dryer was widely used for many kinds of granular grains and seeds,which achieved high-quality,high-efficiency,and low-temperature drying.The heat and mass transfer were strengthened,because the grain changed the flow state spontaneously and rotated continuously during the continuous flow in the dryer.The drying uniformity was improved,further to avoid local overheating damage caused by single-side heating during the grain drying process.The variable cross-section angle box with the angle of 6°could increas the drying dynamic coefficient by 2-4 times,compa

关 键 词：干燥 机械设计 动力系数 干燥工艺 设计理论 

分 类 号：TH11[机械工程—机械设计及理论]