荞麦洁净式脱粒装置设计与仿真

Design and Simulation of Buckwheat Clean Threshing Device

针对传统荞麦脱粒装置--纹杆闭式切流脱粒滚筒装置脱粒过程中籽粒残留和杂质含量高的问题,开展了洁净系统设计研究。该系统包括2个风速入口,每个风速入口由与纹杆脱粒滚筒方向相同的长820 mm、直径27 mm的小型管道构成,每根小型管道上方开有直径12 mm、间隔6 mm的圆孔,用来清理脱粒装置中的残留籽粒。采用ANSYS Fluid Flow(Fluent)流体动力学仿真技术对纹杆闭式切流脱粒装置风场进行模拟仿真。结果表明,当2个入口同时工作并采用12和15 m/s的风速时,清选风速约等于荞麦籽粒的漂浮速度临界值,在此状况下增大风速入口面积,脱粒滚筒和棚格凹板之间的流场速度为3.8~8.3 m/s,大于荞麦籽粒的漂浮速度,棚格凹板下方的流场速度为7~15m/s,且流场内负压减少,是最佳方案。

Aiming at traditional buckwheat threshing device,closed cut-flow threshing drum device with buckwheat,problems of residual grain,and high impurity content during threshing process,a clean system design study was carried out.The system included two wind-speed inlets.Each wind speed inlet was composed of a small pipe with a length of 820 mm and a diameter of27 mm in the same direction as grain barrel threshing drum.Each small pipe had circular holes with a diameter of 12 mm and an interval of 6 mm,used to clean up remaining kernels in the threshing device.The ANSYS Fluid Flow(Fluent)fluid dynamics simulation technology was used to simulate wind field of bar-closed tangential threshing device.Results showed that,when two inlets worked at the same time and wind speeds of 12 and 15 m/s were used,cleaning wind speed approximately equal to critical value of floating speed of buckwheat grains.Under this condition,increasing wind speed inlet area,flow velocity between threshing drum and grid concave plate was 3.8~8.3 m/s,which was greater than floating speed of buckwheat grains;velocity of flow field under the grid concave plate was 7~15 m/s,and negative pressure in the flow field was reduced,which was the best choice.