工程科学学报，第38卷，第2期：194-199,2016年2月 Chinese Journal of Engineering,Vol.38,No.2:194-199,February 2016 DOI:10.13374/j.issn2095-9389.2016.02.006:http://journals.ustb.edu.cn 回转窑内二元颗粒物料的径向混合 陈 辉，肖友刚，赵先琼，刘颖，刘义伦四 中南大学高性能复杂制造国家重点实验室，长沙410000 ☒通信作者，E-mail:csuchenh@csu.edu.cn 摘要研究了颗粒尺寸差异和密度差异对二元物料在回转窑内混合的影响.采用离散单元法建立颗粒物料的运动模型， 模拟滚落运动模式下二元物料在回转窑内的径向混合过程；通过颗粒接触数定义混合程度评价指数，结合Hog的渗流与凝 聚竞争理论分析颗粒体积比σ和密度比η对二元物料混合程度的影响.结果表明：增大体积比σ会增强渗流作用，增大密度 比)会增强凝聚作用，无论渗流或凝聚占据主导作用，均会导致物料在混合过程中产生径向分离，使混合程度降低：对σ与刀 进行配置后，可以使渗流与凝聚两种机理彼此平衡，达到物料混合均匀的目的：物料的渗流一凝聚平衡曲线中，σ与7呈幂函 数关系. 关键词回转窑：固体物料：混合；渗流：凝聚 分类号T355 Transverse mixing of binary solid materials in a rotating kiln CHEN Hui,XIAO You-gang,ZHAO Xian-qiong,LIU Ying,LIU Yi-lun State Key Laboratory of High Performance Complex Manufacturing,Central South University,Changsha 410000,China Corresponding author,E-mail:csuchenh@csu.edu.cn ABSTRACT In order to investigate the effect of particle size difference and density difference on the mixing mechanism of binary granular materials within a rotating kiln,a kinematic model of particles was established using the discrete element method,and the transverse mixing process of granular materials in the rolling regime within the rotating kiln was simulated.The mixing index was defined by contact-number between particles,and the effects of particle volume ratio and density ratio on the mixing index were analyzed using Hong's theory:competition between percolation and condensation.The results show that the percolation mechanism improves with increasing volume ratio o between particles,but the condensation mechanism improves with increasing density ratio n. Segregation will occur in the radial direction of the rotating kiln no matter percolation or condensation plays the leading role resulting in the decrease of mixing degree.Percolation and condensation can balance each other for some reasonable particle volume and density combinations,where the binary granular materials could get uniformly mixed.There is a power function relationship between particle volume ratio and density ratio when percolation and condensation balance each other. KEY WORDS rotary kilns;solid materials;mixing:percolation:condensation 利用回转窑将两种物性不同的物料进行混合是金 及热工效率2，物料良好的混合往往能提高产品的 属治炼、矿物加工、水泥制造等工业中常用的生产工 质量.因此，研究和掌握物料在回转窑内的混合规律 艺”.物料多为固体颗粒状，加入到水平放置的回转 具有重要的工程应用价值. 窑内后，随着回转窑的转动而运动并产生混合.物料 二元物料混合过程中，由于两种物料的颗粒物性 在回转窑内的混合效果直接关系到物料的干燥、研磨 存在差异，容易在回转窑径向方向产生分离现象5。， 收稿日期：2014-1108 基金项目：国家自然科学基金资助项目(51374241,51275531)：湖南省研究生科研创新资助项目(CX2014B059)工程科学学报，第 38 卷，第 2 期: 194--199，2016 年 2 月 Chinese Journal of Engineering，Vol． 38，No． 2: 194--199，February 2016 DOI: 10． 13374 /j． issn2095--9389． 2016． 02． 006; http: / /journals． ustb． edu． cn 回转窑内二元颗粒物料的径向混合 陈 辉，肖友刚，赵先琼，刘 颖，刘义伦 中南大学高性能复杂制造国家重点实验室，长沙 410000  通信作者，E-mail: csuchenh@ csu． edu． cn 摘 要 研究了颗粒尺寸差异和密度差异对二元物料在回转窑内混合的影响． 采用离散单元法建立颗粒物料的运动模型， 模拟滚落运动模式下二元物料在回转窑内的径向混合过程; 通过颗粒接触数定义混合程度评价指数，结合 Hong 的渗流与凝 聚竞争理论分析颗粒体积比 σ 和密度比 η 对二元物料混合程度的影响． 结果表明: 增大体积比 σ 会增强渗流作用，增大密度 比 η 会增强凝聚作用，无论渗流或凝聚占据主导作用，均会导致物料在混合过程中产生径向分离，使混合程度降低; 对 σ 与 η 进行配置后，可以使渗流与凝聚两种机理彼此平衡，达到物料混合均匀的目的; 物料的渗流--凝聚平衡曲线中，σ 与 η 呈幂函 数关系． 关键词 回转窑; 固体物料; 混合; 渗流; 凝聚 分类号 TF355 Transverse mixing of binary solid materials in a rotating kiln CHEN Hui，XIAO You-gang，ZHAO Xian-qiong，LIU Ying，LIU Yi-lun State Key Laboratory of High Performance Complex Manufacturing，Central South University，Changsha 410000，China  Corresponding author，E-mail: csuchenh@ csu． edu． cn ABSTＲACT In order to investigate the effect of particle size difference and density difference on the mixing mechanism of binary granular materials within a rotating kiln，a kinematic model of particles was established using the discrete element method，and the transverse mixing process of granular materials in the rolling regime within the rotating kiln was simulated． The mixing index was defined by contact-number between particles，and the effects of particle volume ratio and density ratio on the mixing index were analyzed using Hong's theory: competition between percolation and condensation． The results show that the percolation mechanism improves with increasing volume ratio σ between particles，but the condensation mechanism improves with increasing density ratio η． Segregation will occur in the radial direction of the rotating kiln no matter percolation or condensation plays the leading role resulting in the decrease of mixing degree． Percolation and condensation can balance each other for some reasonable particle volume and density combinations，where the binary granular materials could get uniformly mixed． There is a power function relationship between particle volume ratio and density ratio when percolation and condensation balance each other． KEY WOＲDS rotary kilns; solid materials; mixing; percolation; condensation 收稿日期: 2014--11--08 基金项目: 国家自然科学基金资助项目( 51374241，51275531) ; 湖南省研究生科研创新资助项目( CX2014B059) 利用回转窑将两种物性不同的物料进行混合是金 属冶炼、矿物加工、水泥制造等工业中常用的生产工 艺［1］． 物料多为固体颗粒状，加入到水平放置的回转 窑内后，随着回转窑的转动而运动并产生混合． 物料 在回转窑内的混合效果直接关系到物料的干燥、研磨 及热工效率［2--4］，物料良好的混合往往能提高产品的 质量． 因此，研究和掌握物料在回转窑内的混合规律 具有重要的工程应用价值． 二元物料混合过程中，由于两种物料的颗粒物性 存在差异，容易在回转窑径向方向产生分离现象［5--6］