滚筒端面对颗粒物料轴向混合过程影响的离散模拟  

Discrete simulation of influence of drum end-wall on axial mixing behavior of granular material

作　　者：侯全勋 董世杰 张泉 冯勇进[5] 王晓宇[5] 刘晓星[2,4] Quanxun HOU;Shijie DONG;Quan ZHANG;Yongjin FENG;Xiaoyu WANG;Xiaoxing LIU(School of Chemical and Environmental Engineering,China University of Mining&Technology,Beijing 100083,China;State Key Laboratory of Multi-phase Complex Systems,Institute of Process Engineering,Chinese Academy of Sciences,Beijing 100190,China;State Key Laboratory of Heavy Oil Processing,China University of Petroleum,Beijing 102249,China;College of Chemistry and Chemical Engineering,University of Chinese Academy of Sciences,Beijing 100049,China;Southwest Institute of Physics,Nuclear Industry,Chengdu,Sichuan 610041,China)

机构地区：[1]中国矿业大学(北京)化学与环境工程学院,北京100083 [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]中国石油大学(北京)重质油国家重点实验室,北京102249 [4]中国科学院大学化学与化工学院,北京100049 [5]核工业西南物理研究院,四川成都610041

出　　处：《过程工程学报》2019年第5期949-958,共10页The Chinese Journal of Process Engineering

基　　金：国家自然科学基金委员会与中国工程物理研究院联合基金资助项目(编号:U1630105);国家重点研发计划资助项目(编号:2017YFE0300602)

摘　　要：基于离散单元法模拟了仅颜色存在差异的两组分颗粒物料在轴径比0.3的窄滚筒中的轴向混合过程,滚筒的左侧端面固定,右侧端面可随侧壁旋转。结果表明,不同物料装载量和滚筒转速下,在达到完全混合状态前,黄红颗粒物料初始轴向界面处可能出现3种不同的径向结构:黄-红结构、红-黄-红结构和红-黄结构。红-黄-红结构和红-黄结构工况下,固定端面一侧还可出现更复杂的多层三明治结构。径向结构源自滚筒端面效应导致的颗粒轴向对流,颗粒轴向速度在切向截面上的分布决定了径向结构的类型。Drum has been widely used to handle granular materials in various industries such as mining, metallurgy and chemical engineering. Thorough understanding of the complex flow behavior of granular material is critical to the design, optimization and scale-up of drum apparatus. A rather short rotating drum with the ratio of axial length to diameter equal to 0.3 was focused in this work. By performing discrete element method(DEM) simulations, the axial mixing process of binary granular material in such short drum was investigated. The drum was asymmetrically operated with the left end-wall fixed and the other rotated with side wall. The particles only differed in color(yellow versus red). The yellow and red particles were initially arranged side by side axially. The simulation results indicated that the system inevitably went through a radial segregation state before attaining the full mixing state. Depending on the filling degree and rotating speed, there could be three types of radial pattern at the initial axial interface of yellow and red materials: yellow-red, red-yellow-red and red-yellow. As to cases of the latter two structures, a more complex multi-layer sandwich type radial segregation pattern could be observed in the half side close to the fixed end wall. The analyses of the axial flow structure demonstrate that the occurrence of radial pattern can be ascribed to the end-wall effect: due to the asymmetrical operation of end-walls, clear axial convection structure was formed. And the exact distribution of particle axial velocity in the transverse cross-section determined the type of radial segregation.

关 键 词：颗粒物料 径向偏析 对流 数值模拟 离散单元法 

分 类 号：TQ027.1[化学工程]