为提高茶叶风选效果,采用理论分析和流体动力学数值仿真的方法研究了风选过程中茶叶颗粒的运行轨迹和风选室内流场的状态,并进行了相关试验验证。研究表明,茶叶风选机送风口风速分布采用上小下大方案时茶叶颗粒群有效漂移间距最大;风选室内部由于结构原因存在涡旋现象,4号和5号出茶口流出的茶叶颗粒相对质轻,其漂移轨迹较易受到涡旋的影响,可以通过设置扰流板加以减轻,且能有效降低各口茶叶混入其他口茶叶的比例,提高风选质量。
In order to improve the quality of tea wind-selecting, tea particles’ running track and indoor flow state of winnowing room were studied by the methods of theoretical analysis and fluid dynamics simulation, and combined with experimental verification. The results showed that the effective drift distance between particles of different weight is greater than the other air velocity distribution program when the air velocity distribution near wind crossing was set at rising from the top to the bottom. Vortexes are found in winnowing room due to structural reasons. Trajectory of tea in No. 4 and No. 5 export is more susceptible to the disturbance of the vortex because of its weight. Vortex could be decreased by using spoiler, which will also reduce the proportion of mixed tea and improve the winnowing quality.
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