Estimating energy in grinding using DEM modelling
Estimating energy in grinding using DEM modelling
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DOI：
10.1016/j.mineng.2015.10.013
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发表时间：
2016
影响因子：
4.8
通讯作者：
N. Weerasekara;Lian X. Liu;M. Powell
中科院分区：
文献类型：
--
作者：
N. Weerasekara;Lian X. Liu;M. Powell
离散元方法(DEM)的最新技术和增加的计算能力能够结合和解决碾磨机等粉碎设备中的复杂物理问题。使用最新的DEM软件工具，可以对磨机内的散体颗粒动力学进行全面的3D模拟。本文探讨了使用DEM技术的磨机内的破碎环境，以及如何扩展这些技术，为磨机和粉碎设备建模提供更有用的数据。通过改变磨机大小和装药粒度分布进行了一系列DEM模拟，以探索和了解使用DEM技术的磨机内的破碎环境。通过考虑粉碎机的总能量消耗和碰撞环境的性质对每个粉碎机进行了分析。DEM模拟表明，粉碎机的装药粒度分布对粉碎机的输入功率和能量在装药之间的分配方式有很大的影响。较小的颗粒经历较高的能量，而较大的颗粒经历较少的能量，但这种变化强烈地依赖于磨机的尺寸。结果还表明，平均颗粒碰撞能随着磨矿粒度的增大而增大，但其在粒度上的分布受磨矿含量、粒度分布的影响很大。模拟还捕捉到了滚流装药不同区域内的能量分布，其中趾部撞击区具有较高的撞击能量，而整体剪切区具有较高的切向能量。无论磨机的大小如何，大部分能量都被中等尺寸范围内的粒子消耗，该粒子在总电荷分布中的质量百分比最高。
The latest state of the art on Discrete Element Method (DEM) and the increased computational power are capable of incorporating and resolving complex physics in comminution devices such as tumbling mills. A full 3D simulation providing a comprehensive prediction of bulk particle dynamics in a grinding mill is now possible using the latest DEM software tools.This paper explores the breakage environment in mills using DEM techniques, and how these techniques may be expanded to provide more useful data for mill and comminution device modelling. A campaign of DEM simulations were performed by varying the mill size and charge particle size distribution to explore and understand the breakage environment in mills using DEM techniques. Analysis of each mill was conducted through consideration of the total energy dissipation and the nature of the collision environment that leads to comminution.The DEM simulations show that the mill charge particle size distribution has a strong influence on the mill input power and on the way the energy is distributed across the charge. The smaller particles experience higher energies while the larger experience less, but this variation is strongly dependent on the mill size. The results also showed that the average particle collision energy increases with increasing mill size, whereas its distribution over particle size is strongly influenced by the mill content particle size distribution. The simulations also captured the energy distribution within different regions of the tumbling charge, with the toe impact region having higher impact energies and the bulk shear region having higher tangential energies. Regardless of the mill size most of the energy is consumed by the particles in the mid-size range, which has the highest percentage mass of the total charge distribution.