基于EDEM-Fluent的荞麦旋风分离清选装置研究

Buckwheat cyclone separation and cleaning device based on EDEM-Fluent

【目的】设计适合荞麦清选的旋风分离清选装置,为提高我国荞麦的机械化收获水平提供支持。【方法】以“西农9979”品种荞麦为试验对象,测定荞麦和籽粒的主要物料特性,采用EDEM-Fluent耦合的仿真方法,对旋风分离筒不同截面的气流速度云图和荞麦籽粒在旋风分离筒内的运动进行分析,并对清选的清洁率和损失率进行仿真。【结果】Fluent仿真分析表明,旋风分离筒轴向气流对称性较好,基本不受入口位置的影响,中心轴处气流速度约为10 m/s,筒壁周围的气流速度约为5 m/s。喂入口位于分离筒上部时,在径向截面处的喂入口气流速度和分离筒内筒壁周围的气流速度相同,可能造成荞麦籽粒的大量损失。EDEM仿真分析表明,旋风分离筒喂入口位于上部、中部和下部时,清洁率分别为99.50%,98.80%和98.28%,损失率分别为8.456%,0.433%和0.260%。根据仿真结果,选择喂入口位于旋风分离筒中部,台架验证试验结果表明,所设计荞麦旋风分离筒的平均清洁率为94.78%,平均损失率为1.67%,可以较好地实现荞麦的分离和清选。【结论】所设计荞麦旋风分离清选装置可以满足荞麦旋风分离清选的需要。

【Objective】To improve the level of mechanized harvesting of buckwheat in China,a cyclone separation and cleaning device for buckwheat cleaning was designed.【Method】Main material properties of buckwheat and grains of Xinong 9979 were measured.Using EDEM-Fluent coupling simulation,the airflow velocity contour of different sections in the cyclone separator and the movement of buckwheat grains in the cyclone separator were analyzed.The cleaning rate and loss rate were also simulated.【Result】The Fluent simulation analysis showed that the axial airflow symmetry in the cyclone separator was good,and it was basically not affected by inlet position.The airflow velocity at the central axis was about 10 m/s and the velocity around the cylinder wall was about 5 m/s.When the feeding inlet was located in the upper part,the air velocity of the feeding inlet at the horizontal section was the same as the air velocity around the inner cylinder wall,which may cause large losses of buckwheat grains.When the feeding inlet was located in the upper,middle and lower parts,the cleaning rates were 99.50%,98.80%and 98.28%and the loss rates were 8.456%,0.433%and 0.260%,respectively.According to simulation results,the determined feeding inlet was located in the middle of the cyclone separator,and the bench test showed that the average cleaning rate was 94.78%and the average loss rate was 1.67%.【Conclusion】The designed buckwheat cyclone separation and cleaning device met the needs of buckwheat cyclone separation and cleaning.