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过程工程学报 ›› 2023, Vol. 23 ›› Issue (2): 207-215.DOI: 10.12034/j.issn.1009-606X.222030

• 研究论文 • 上一篇    下一篇

滚筒端面对颗粒物料轴向流动特性影响的离散模拟研究

王兴坤1， 张旭辉1， 郭辉2,3， 刘晓星2,3*   

  1. 1. 北京国电富通科技发展有限责任公司，北京 100070 2. 中国科学院过程工程研究所多相复杂系统国家重点实验室，北京 100190 3. 中国科学院大学化学工程学院，北京 100049
  • 收稿日期:2022-01-24 修回日期:2022-04-12 出版日期:2023-02-28 发布日期:2023-03-01
  • 通讯作者: 刘晓星 xxliu@ipe.ac.cn
  • 作者简介:王兴坤，硕士，机械工程师，从事低阶煤分质综合利用研究工作；通讯联系人，刘晓星，研究员，从事颗粒物质介尺度科学研究，E-mail: xxliu@ipe.ac.cn

Discrete modeling of the end-wall effect on particle axial movement in horizontal drum

Xingkun WANG1,  Xuhui ZHANG1,  Hui GUO2,3,  Xiaoxing LIU2,3*   

  1. 1. Beijing Guodian Futong Science and Technology Development Co., Ltd., Beijing 100070, China 2. State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China 3. School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2022-01-24 Revised:2022-04-12 Online:2023-02-28 Published:2023-03-01
  • Contact: LIU Xiao-xing xxliu@ipe.ac.cn

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摘要： 针对碎渣工艺中仅一个端面可随侧壁转动的短滚筒体系，采用离散单元法模拟研究了滚筒轴径比和转动速度对颗粒物料轴向流动特性的影响。模拟结果表明，系统内形成了显著的轴向对流结构：物料层顶部处颗粒物料会朝向滚筒固定端面一侧运动，而物料层趾部区域颗粒则朝向滚筒转动端面一侧运动。低转速条件下，沿物料自由表面由顶部到趾部，颗粒轴向速度呈非对称分布，顶部区域颗粒轴向速度绝对值显著小于趾部区域颗粒轴向速度绝对值；两部分区域颗粒轴向速度绝对值分别在y/R=±0.725处达到极大值，且轴向速度为0的位置并不出现在切向的中间位置。改变滚筒的轴长对这种非对称分布的影响近似可忽略，但是增大滚筒转速会增大颗粒轴向运动速度并逐步减弱这种非对称性。改变滚筒转速，对物料顶部区域颗粒的轴向流动的影响要大于对趾部区域颗粒轴向流动的影响。当滚筒轴径比达到1.2后，滚筒转动端面对物料轴向流动的影响区域不会随滚筒转速的增大而呈现显著变化。这些结果为实际滚筒碎渣工艺的结构优化提供了理论指导。

关键词: 离散单元法, 颗粒物质, 滚筒, 流动特性

Abstract: Aiming at the short drum system in which only one end face can rotate with the side wall in the slag crushing process, the discrete element method (DEM) is used to simulate and study the influence of the drum length-diameter ratio and rotation speed on the axial flow characteristics of granular materials. Simulation results indicate that distinct axial convention occurs inside the system: particles in the upstream zone tend to move towards the fixed end-wall side, whereas those in the downstream zone are apt to shift towards the rotating end-wall side. At low rotating speed condition, along the transverse direction the axial velocity profile of particles at the free surface presents an asymmetric characteristic. The axial velocity magnitude of particles in the upstream zone is clearly smaller than that of particles in the downstream zone. The axial velocity magnitude of particles in the two zones reaches the maximum value at y/R=±0.725, and the position where the axial velocity is 0 does not appear in the tangential middle position. Such asymmetric characteristic is nearly independent on the axial length of the drum, whereas increasing the rotational speed of the drum will increase the axial velocity of the particles and gradually reduce this asymmetry. Changing the rotating speed of the drum has a greater effect on the axial flow of particles in the upstream zone of the material than on the axial flow of particles in the downstream zone. When the length-diameter ratio of the drum reaches 1.2, the influence area of the rotating end-wall on the axial flow of the material will not change significantly with the increase of the rotating speed of the drum. The simulation results thus provide helpful guidelines for the future optimization of the real drum system used for particle milling.

Key words: discrete element method (DEM), granular material, rotating drum, axial flow