立式螺旋搅拌磨机磨矿机理研究及动力学仿真分析

发布时间：2018-04-08 18:38

本文选题：立式螺旋搅拌磨机　切入点：旋转流体动力学　出处：《西华大学》2015年硕士论文

【摘要】：随着高品位易选矿石资源大规模开采利用使简单、易选矿资源正面临日益短缺的局面;储量丰富的贫、细、杂的低品位难选矿石资源开发利用率逐年增加。相比于易选矿,难选矿的选别困难、能量利用率低却是不争的事实。立式螺旋搅拌磨机作为一种高效、节能的超细磨设备,对于细粒嵌布的难选矿能进行有效的磨矿、再磨和选矿。虽然立式螺旋搅拌磨机已经广泛应用于金属和非金属的磨矿作业中,但是关于塔磨机磨矿作业时筒体内矿料的运动方式、筒体内矿料的速度和压力变化情况以及螺旋搅拌器在磨矿过程中的受力情况的研究相对较少。本文结合立式螺旋搅拌磨机的磨矿工作原理,通过分析其工作原理完成以下几个方面工作:(1)详细的分析和研究立式螺旋搅拌磨机磨矿的工作原理,对磨矿过程中矿料的运动方式及两种循环运动进行分析说明;介绍了塔磨机在磨矿过程中的两种磨矿机理:摩擦研磨机理和撞击粉磨机理;最后结合磨矿工作原理分析了矿料在磨矿作业时两种层流运动:离心沉降和重力沉降。(2)参考惯性坐标系和非惯性坐标系之间的关系,利用惯性柱坐标推导出非惯性旋转坐标系,建立了塔磨机流体域进行旋转流体动力学建模;从微观的角度分析矿料颗粒的运动方式。(3)根据立式螺旋搅拌磨机磨矿时矿料占据在筒体中的位置关系对塔磨机流体域进行三维整体建模,结合ANSYS-FLUENT软件对流体域进行了试运行磨矿作业流体仿真,利用仿真结果验证了塔磨机流体域建模的正确性,并为接下来的立式螺旋搅拌磨机的铁精矿FLUENT仿真提供了模型依据。(4)在塔磨机流体域正确建模的前提下,文章使用ANSYS-FLUENT软件对立式螺旋搅拌磨矿研磨铁精矿的磨矿作业进行流体仿真。通过对筒体内流体域运动方式、两相流材料设置(铁精矿和水)、interface面结合和适当的迭代步数设置等操作进行塔磨机流体仿真实验,利用仿真结果的速度云图和压力云图来分析塔磨机磨矿时的运动状况;同时结合塔磨机流体域FLUENT仿真,利用ANSYS-Workbench对螺旋搅拌器进行单相流固耦合分析,仿真出螺旋搅拌器在磨矿时的应力变化情况和螺旋叶片变形情况。进而仿真结果给塔磨机螺旋搅拌器设计提供了重要的依据;同时对螺旋搅拌器进行了模态分析,仿真出其在前八阶的模态振型图。
[Abstract]:With the large-scale exploitation and utilization of high grade and easy ore resources, the easy ore dressing resources are facing an increasingly short situation, and the utilization ratio of poor, fine and miscellaneous low grade refractory ore resources with rich reserves is increasing year by year.Compared with easy dressing, it is difficult to separate difficult ore, but low energy utilization ratio is an indisputable fact.As a kind of high efficiency and energy saving ultrafine grinding equipment, vertical screw mixing mill can effectively grind, remill and concentrate fine particles.Although vertical screw mixing mills have been widely used in metal and non-metallic grinding operations, the movement of ore in the cylinder during the grinding operation of the tower mill is concerned.There are few researches on the variation of the velocity and pressure of the ore in the cylinder and the stress of the screw agitator in the grinding process.In this paper, the grinding principle of vertical screw mixing mill is analyzed and the working principle of vertical screw mixing mill is studied by analyzing its working principle in the following aspects: 1.This paper analyzes the movement mode and two kinds of circulating movement of ore in grinding process, introduces two kinds of grinding mechanism of tower mill in grinding process: friction grinding mechanism and impact grinding mechanism;Finally, the relationship between the reference inertial coordinate system and the non-inertial coordinate system is analyzed, and the non-inertial rotating coordinate system is derived from the inertial cylindrical coordinate system.The rotary hydrodynamic modeling of tower mill was established in the fluid domain.According to the position relation of the ore material occupied in the cylinder in the grinding process of the vertical screw agitator, the three-dimensional integral modeling of the fluid domain of the tower mill is carried out from the microscopic point of view.Combined with ANSYS-FLUENT software, the fluid simulation of trial-running grinding operation is carried out, and the correctness of modeling in fluid domain of tower mill is verified by simulation results.It also provides the model basis for the FLUENT simulation of iron concentrate of the vertical screw agitator under the premise of the correct modeling in the fluid domain of the tower mill.In this paper, ANSYS-FLUENT software is used to simulate the grinding operation of helical agitation grinding iron concentrate.The fluid simulation experiment of tower mill was carried out by means of fluid domain motion mode, two phase flow material setting (combination of iron concentrate and water surface and appropriate iterative step setting etc.)The velocity cloud diagram and pressure cloud diagram of the simulation results are used to analyze the movement of the mill grinding machine, and the single-phase fluid-solid coupling analysis of the screw mixer is carried out by using ANSYS-Workbench combined with the FLUENT simulation in the fluid domain of the tower mill.The stress change and screw blade deformation of screw agitator during grinding are simulated.The simulation results provide an important basis for the design of spiral stirrer of tower mill, and at the same time, the modal analysis of spiral stirrer is carried out, and the modal mode diagram of the first eight steps is simulated.
【学位授予单位】：西华大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD453

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