垂直螺旋输送机中颗粒速度的分布  

Distribution of Particle Velocity in a Vertical Screw Conveyor

作　　者：赵占一[1] 孟文俊[1] 孙晓霞[1] 蒋权[1] 张立勇[1] 

机构地区：[1]太原科技大学机械工程学院,山西太原030024

出　　处：《过程工程学报》2015年第6期909-915,共7页The Chinese Journal of Process Engineering

基　　金：国家自然科学基金资助项目(编号:51575370);山西省科学技术发展计划(工业)资助项目(编号:20140321008-04);山西省煤基重点科技攻关项目资助(编号:MJ2014-09)

摘　　要：采用离散元方法对垂直螺旋输送机中颗粒的流动进行模拟计算,得到颗粒圆周速度、轴向速度、自转角速度在螺旋空间中的分布.结果表明,颗粒圆周速度最大在叶片工作面径向位置33 mm处,右下区域内圆周速度变化明显,颗粒受周向剪切力较大.随径向距离增加,底层颗粒与叶片的圆周速度差变大,至近料槽壁处达峰值,导致叶片远端和边缘处磨损较大.较大颗粒轴向速度区域在颗粒床中层,最大值在近料槽壁处叶片工作面上方22 mm处.在左下角出现颗粒流滞流区,颗粒轴向速度小于0.1605 m/s,有些甚至小于0.09625 m/s.螺旋叶片工作面附近颗粒自转角速度较大,最大值在叶片边缘,且高自转角速度的颗粒都集中在颗粒群下层.Particle flow in a vertical screw conveyor was simulated with discrete element method. In the simulation, the distributions of circular velocity, axial velocity and rotation angular velocity of particles were obtained in the helix space. The results reveal that the maximum circumferential velocity of the particle bed appears on the leading face of screw blade, and the distance of the maximum point to center axis is 33 mm. The circular velocity gradient changes obviously in the bottom right corner of particle bed. So shearing force between particles in peripheral direction is relatively large in that area. The circular velocity difference between the blade and the particles in the bottom of particle bed becomes larger with the increase of radial distance. And its peak value occurs near the casing wall. The particles with larger axial speed exist in the middle of particle bed, which will lead to wearing along the edge of leading face of the blade. The maximum point of axial speed of particles is located at 22 mm above the leading face of the screw and near the casing wall. Stagnating flow area appears in the bottom left of particle bed. The axial velocity of particles in that area is lesser than 0.160 5 m/s, some of them even less than 0.096 25 m/s. The particles with high rotation angular velocity appear on the leading face of screw blade. The maximum point of rotation angular velocity appears at the edge of screw blade. And the particles with high rotation angular velocity appear on the bottom of the particle group.

关 键 词：垂直螺旋输送机 离散元方法 颗粒流 速度分布 磨损 

分 类 号：TH224[机械工程—机械制造及自动化]