基于统计力学原理的半自磨机衬板结构优化设计

发布时间：2018-10-20 14:22

【摘要】：半自磨机由于其工艺流程短磨矿效率高等优点,逐渐发展成为当前矿业领域中运用最广泛的破碎设备之一。半自磨机筒体衬板作为影响磨机磨矿性能的关键部件之一,目前仍然存在着不合理选型的问题,因此找出衬板结构参数对半自磨机磨矿性能的影响关系,为衬板结构设计提出合理建议和优化方案显得尤为重要。本文采用理论研究、数值模拟和试验验证相结合的方法完成以下工作:基于统计力学原理分析半自磨机衬板结构参数对载荷颗粒运动形态的影响规律;运用动力学方法建立起以衬板结构参数为变量的半自磨机有用功率数理模型;根据模型分析了半自磨机衬板结构参数对磨矿性能的影响趋势和最优范围;利用数值模拟和试验验证的方法,论证模型的可靠性。综上研究得出以下结论:(1)通过分析半自磨机内部各层级载荷颗粒的运动轨迹和运动状态,发现相近层级下的载荷颗粒具有相似的运动规律,利用这一统计学规律建立起了载荷分布区域的划分准则,将半自磨机内部载荷划分成提升区、死区、泻落区和抛落区。(2)通过上述区域的划分,对半自磨机内部各区域的载荷颗粒展开动力学分析,建立起半自磨机有用功率数学模型,通过选取该模型中有用功率和机械效率作为评价指标,在数理分析层面指出了半自磨机衬板形状和结构参数对破碎效果和破碎效率的影响趋势,获得了衬板结构参数的优化设计范围。(3)采用离散元法对半自磨机展开数值模拟,统计分析了衬板结构参数对磨机内部载荷颗粒的抛落数量、区域分布和粘结颗粒(物料)断裂键数量的影响,得出了半自磨机衬板结构参数对磨矿性能的影响趋势及优化范围,该结论与模型分析相符,证明了模型在数值模拟中对半自磨机衬板结构参数优化的可靠性。(4)设计磨矿试验以-1mm粒度产品的产量及破碎比能耗作为评价指标,得出了衬板结构参数变化对半自磨机磨矿效果和功能转化效率的影响趋势及最优组合,与模型和数值分析得出的结论基本相符,进一步验证了半自磨机有用功率数学模型的可靠性。综上所述,通过对半自磨机内部载荷颗粒的运动规律展开统计分析,并结合衬板结构参数建立有用功率数学模型,对半自磨机衬板结构的优化设计具有良好的适用性和可靠性,为半自磨机衬板结构提供了切实可行的数理模型分析方法,在半自磨机增产降耗和提高磨矿性能等方面具有较好的理论研究意义和实际应用价值。
[Abstract]:Due to the advantages of high short grinding efficiency, semi-autogenous mill has gradually developed into one of the most widely used crushing equipment in the field of mining industry. As one of the key components affecting the grinding performance of the mill, the liner of the semi-self-grinding machine still has the problem of unreasonable selection, so the relationship between the structural parameters of the liner and the grinding performance of the semi-self-grinding machine is found out. It is very important to put forward reasonable suggestion and optimization scheme for the design of liner structure. In this paper, theoretical research, numerical simulation and experimental verification are used to complete the following work: based on the statistical mechanics principle, the influence of structural parameters of lining plate of semi-self-grinding machine on the motion of loaded particles is analyzed. The mathematical model of useful power of semi-self-grinding machine is established by using dynamic method, and the influence trend and optimal range of structural parameters of lining plate on grinding performance are analyzed according to the model. The reliability of the model is demonstrated by numerical simulation and experimental verification. The main conclusions are as follows: (1) by analyzing the motion trajectory and motion state of the loading particles in the semi-self-grinding machine, it is found that the load particles in the similar levels have similar motion laws. By using this statistical law, the dividing criterion of load distribution region is established, and the internal load of semi-autogenous mill is divided into lifting zone, dead zone, cathartic zone and falling area. (2) through the division of the above mentioned areas, the internal load is divided into three parts: lifting zone, dead zone, falling area and falling area. The dynamic analysis of the load particles in each region of the semi-self-mill is carried out, and the mathematical model of the useful power of the semi-self-mill is established. The useful power and mechanical efficiency in the model are selected as the evaluation indexes. At the level of mathematical analysis, the influence trend of the shape and structure parameters of semi-self-mill liner on crushing effect and crushing efficiency is pointed out, and the optimum design range of structural parameters of lining plate is obtained. (3) the numerical simulation of semi-self-mill is carried out by using discrete element method. The influence of structural parameters of lining plate on the quantity of load particles, the area distribution and the number of fracture bonds of bonded particles in the mill are analyzed statistically. The influence trend and optimization range of structural parameters of lining plate of semi-self-grinding machine on grinding properties are obtained. The conclusion is consistent with the model analysis, and proves the reliability of the model in the optimization of the structural parameters of the semi-self-mill liner in the numerical simulation. (4) the production and crushing specific energy consumption of the-1mm granularity product are used as the evaluation indexes in the design of the grinding test. The influence trend and optimal combination of lining structure parameters on grinding effect and function conversion efficiency of semi-self-grinding mill are obtained, which are basically consistent with the conclusion of model and numerical analysis. The reliability of the mathematical model of the useful power of the semi-self mill is further verified. To sum up, through the statistical analysis of the movement law of the inner load particles of the semi-self-mill and the establishment of the useful power mathematical model combined with the structural parameters of the lining plate, it has good applicability and reliability for the optimization design of the lining plate structure of the semi-self-grinding machine. It provides a feasible mathematical model analysis method for lining structure of semi-self-grinding machine and has good theoretical research significance and practical application value in increasing production and reducing consumption and improving grinding performance of semi-self-mill.
【学位授予单位】：江西理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD453

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