Abstract: In order to further meet the requirements of low energy consumption and high efficiency in rapeseed drying process, this paper designed a small rapeseed circulating and drying machine by solar hot air. Its device relied on solar collector to provide hot air. The drying chamber provided a pair of screen impeller turning in the opposite direction. The rotating impeller could extend the rapeseed retention time on air, and the bucket elevator could make rapeseed move circularly in the drying device. Rapeseed was tested as a drying object to find out the changes in moisture content, hot air wind speed from the drying room inlet, screen impeller rotation speed, material circulation rate, etc., so as to obtain optimal equipment operating conditions combined with these experimental results. The results showed that by the corrugated solar collectors, the inlet hot air speed, material circulation speed and rotation speed of screen impeller were 5 m/s, 800 kg/h and 50 r/min, respectively. The drying efficiency of rapeseed could reach a maximum level, which could met daily drying requirement of 250 kg could be met.

Key words: rapeseed, solar energy, hot air, circulation, moisture content, drying efficiency

摘要： 为进一步满足油菜籽干燥过程中低能耗高效率的要求，设计研制了一种小型太阳能热风油菜籽循环干燥设备。设备依靠太阳能集热器提供热风，干燥室内设有一对转向相反的筛网叶轮，转动的叶片延长油菜籽滞空时间，斗式提升机实现物料循环干燥。以油菜籽为干燥对象进行试验，研究干燥室进口热风风速、筛网叶轮转速、物料循环速率对含水率变化的影响，结合试验结果获得设备最优运行工况。试验结果表明：当使用波纹型太阳能集热器，进口风速为5 m/s，物料循环速率为800 kg/h，筛网叶片转速50 r/min时，油菜籽干燥速率最高，可满足日干燥量250 kg的干燥需求。

关键词: 油菜籽, 太阳能, 热风, 循环, 含水率, 干燥效率