复合曲锥旋流器分离性能研究.pdf

中图分类号TD454学校代码10424 UDC密级公开 山东科技大学 工程硕士学位论文 复复合合曲曲锥锥旋旋流流器器分分离离性性能能研研究究 Study on Separation Perance of Hydrocyclone withCompositeCurvedConicalSection 作者许慧林入学时间 2017. 09 导师刘培坤职称教 授 副 导 师李红强职称高级工程师 申请学位工程硕士所在学院机械电子工程学院 学科（类别）工程硕士方向（领域）动力工程 答辩日期2020.06.07提交日期2020.06 摘摘要要 常规旋流器的锥段为直线型锥，在生产过程中伴有不同程度的“溢流跑粗”和“底流夹 细”现象，分离精度和效率有待提高。为提高旋流器的分离性能，本文提出并设计了复合曲 锥旋流器，其具有上锥段向轴心内凹，下锥段由轴心向外凸的结构特征，并通过理论分析、 数值模拟和试验的方法对该结构的分离性能展开研究。 首先，对比分析了常规直锥和复合曲锥旋流器的分离性能，结果表明与常规直锥旋 流器相比，复合曲锥旋流器在上锥段内流体的切向速度和外旋流轴向速度提高，下锥段内 流体的切向速度和外旋流轴向速度降低，促使零速包络面向下延展和高密度悬浮层形成， 粗、细粒径的颗粒分布更加合理；深入研究了曲率指数对复合曲锥旋流器内部流场特性和 分离性能的影响规律，在考察范围内确定曲率指数 n3 为最优设计参数，此时 5μm 颗粒 底流回收率由 5.74减少至 2.72，50μm 颗粒底流回收率由 90.75增加到 93.24，分离 精度提高。通过试验验证了数值模拟结果的准确性，底流夹细和溢流跑粗现象得到明显改 善，各粒级颗粒的综合分级效率均有所提高。 随后，为指导复合曲锥旋流器在生产实践中应用，探索了不同底流口直径、进料压力 和进料浓度对其分离性能的影响规律，结果表明随着底流口直径增大，旋流器内零速包 络面上移，削减了高密度悬浮层，各粒级颗粒的底流回收率都增加，分离粒度降低；随着 进料压力增大，旋流器内流体的切向速度增大，颗粒更倾向于向底流口方向运动，各粒级 颗粒的底流回收率增加，分离粒度降低；随着进料浓度增加，旋流器内流体的切向速度减 小，高密度悬浮层进一步延展，各粒级颗粒的底流回收率减小，分离粒度增加。结合产物 的浓度、粒度组成、固相产率和综合分级效率等指标，指出了各工艺参数所适用的生产作 业，对实践应用具有一定的指导意义。 最后，应用复合曲锥旋流器设计了旋流脱泥工艺，成功应用于甘肃某白钨矿的选矿作 业中。 通过该工艺抛除了占原矿 6.65的不可浮选细泥， 细泥中小于 10μm 颗粒占 91.67， 小于 20μm 颗粒占 100，达到了精确抛除的目的。通过全流程试验后，钨精矿 WO3回收 率提高了 3.88 个百分点，品位提高了 6.80 个百分点，减少了选矿药剂消耗，促进了生产 顺行，提高了企业效益。 本研究对丰富旋流器的结构型式，提高旋流器的分离精度和效率，改善分级、分选等 作业技术指标，提高生产效率和资源利用率具有重要意义。 关键词关键词复合曲锥旋流器；分离精度；分离效率；数值模拟；试验研究 Abstract The conventional hydrocyclone is characterized by linear cone section and it is always accompanied by the phenomenon of “overflow mixed with coarse particle“ and “underflow mixed with fine particle“ during the production process. The separation accuracy and efficiency need to be improved. In order to improve the separation perance of the hydrocyclone, a hydrocyclone with composite curved conical section is proposed and designed in this paper. Its structural characteristics is that the upper cone segment is concave curve while the lower cone segment is convex curve. The separation perance is studied by theoretical analysis, numerical simulation and experimental s. Firstly, the separation perance of hydrocyclone with conventional linear cone and hydrocyclone with composite curved conical section is compared and analyzed. The results show that compared with the fluid velocity inside the conventional hydrocyclone, the tangential velocity and the axial velocity of outer spiral flow inside the new hydrocyclone increased in the upper cone, but decrease in the lower cone. The velocity change promotes the extension of zero-velocity axial envelope and the ation of a high-density suspension layer, making the coarse and fine particle distribution more reasonable. The effects of the curvature index n on the flow field characteristics and separation perance of the hydrocyclone are comprehensively studied. Under the research range, the optimal curvature index n 3 is determined. Here, the underflow recovery rate of 5μm particles is reduced from 5.74 to 2.54, and the underflow recovery rate of 50μm particles is increased from 90.75 to 92.97, showing that the separation accuracy has been improved. The accuracy of the numerical simulation results is proved by later experiments. The phenomenon of “overflow mixed with coarse particle“ and “underflow mixed with fine particle“ is improved obviously and the classification efficiency of each size particle increases. Subsequently, in order to guide the application of the hydrocyclone with composite curved conical section, the influence rules of different apex diameters, feed pressure and feed concentration on the separation perance are explored. The results show that as the apex diameter increases, the zero-velocity axial envelope surface moves upward, weakening the high-density suspension layer. The underflow recovery rate of each size particle increases, but the cut size decreases. With the increase of feed pressure, the tangential velocity in the hydrocyclone increases, making the particles tend to move toward the underflow, therefore the underflow recovery of each size particle increases, but the cut-size decreases. With the increase of feed concentration, the tangential velocity in the hydrocyclone decreases, as a result the high-density suspension layer is further extended, the underflow recovery of each particle size decreases, but the cut-size increases. Combining the indicators of product concentration, particle size composition, solid phase yield and comprehensive efficiency, the paper presents the production operation applicable to each process parameter, which has certain guiding significance for practical application. Finally, a desliming process is designed by using the hydrocyclones with composite curved conical section, and successfully applied to the beneficiation operation of a scheelite mine in Gansu Province. Through this process, 6.65 of the non-floatable fine mud of the original ore is thrown away. The particles smaller than 10 μm account for 91.67 and the particles smaller than 20 μm account for 100 in the fine mud, achieving the goal of exact discarding. After the whole process test, the WO3recovery rate of tungsten concentrate increases by 3.88 percentage points, and the grade increases by 6.80 percentage points. The consumption of beneficiating agents has been reduced, and the production has been promoted, increasing the economic benefits for the entreprise. This study is of great significance for enriching the structure of the hydrocyclone, increasing the separation accuracy and efficiency, improving the operation technical indicators such as classification and sorting, and improving production efficiency and resource utilization. Keywords Hydrocyclone with composite curved conical section; Separation accuracy; Separation efficiency; Numerical simulation; Experimental research 目目录录 图清单..............................................................................................................................................I 表清单........................................................................................................................................... III 变量注释表.....................................................................................................................................V 1 绪论............................................................................................................................................. 1 1.1 研究背景.......................................................................................................................... 1 1.2 研究目的及意义.............................................................................................................. 1 1.3 国内外研究现状.............................................................................................................. 2 1.4 主要研究内容和创新点.................................................................................................. 5 2 理论基础..................................................................................................................................... 6 2.1 旋流器的基本理论.......................................................................................................... 6 2.2 旋流器内部流场分布...................................................................................................... 8 2.3 旋流器的性能评价指标................................................................................................ 13 2.4 计算流体力学理论基础................................................................................................ 15 2.5 本章小结........................................................................................................................ 19 3 复合曲锥旋流器的数值模拟................................................................................................... 20 3.1 几何模型的建立与网格划分........................................................................................ 20 3.2 边界条件及参数设置.................................................................................................... 22 3.3 复合曲锥与常规直锥旋流器的对比............................................................................ 23 3.4 工艺参数对复合曲锥旋流器分离性能的影响............................................................ 30 3.5 本章小结........................................................................................................................ 37 4 复合曲锥旋流器分离性能试验............................................................................................... 38 4.1 试验设计........................................................................................................................ 38 4.2 对比试验结果分析........................................................................................................ 40 4.3 单因素试验结果分析.................................................................................................... 42 4.4 本章小结........................................................................................................................ 48 5 工艺设计和应用试验............................................................................................................... 49 5.1 矿石性质........................................................................................................................ 49 5.2 工艺流程设计................................................................................................................ 50 5.3 试验结果及分析............................................................................................................ 51 5.4 本章小结........................................................................................................................ 52 6 结论与展望............................................................................................................................... 53 6.1 主要结论........................................................................................................................ 53 6.2 工作展望........................................................................................................................ 54 参考文献 附录 作者简历 致谢 学位论文数据集 Contents List of Figures.................................................................................................................................I List of Tables............................................................................................................................... III List of Variables............................................................................................................................V 1 Introduction.................................................................................................................................1 1.1 Research background.........................................................................................................1 1.2 Purpose and significance of the research...........................................................................1 1.3 Research status at home and abroad..................................................................................2 1.4 Main research contents and innovations............................................................................5 2 Theoretical basis......................................................................................................................... 6 2.1 Basic theory of hydrocyclone............................................................................................6 2.2 Internal flow field distribution in hydrocyclone................................................................8 2.3 Perance uation index of hydrocyclone.............................................................. 13 2.4 Computational fluid mechanics theory............................................................................15 2.5 Summary..........................................................................................................................19 3 The numerical simulation of hydrocyclone with composite curved conical section...........20 3.1 Establishment of geometric model and mesh..................................................................20 3.2 Boundary conditions and parameter settings...................................................................22 3.3 Comparison of composite curved cone and linear cone hydrocyclone........................... 23 3.4 Effect of process parameters on separation perance................................................30 3.5 Summary..........................................................................................................................37 4 Separation perance test of hydrocyclone with composite curved conical section...... 38 4.1 Test design.......................................................................................................................38 4.2 Analysis of comparative test results................................................................................ 40 4.3 Analysis of single factor test results................................................................................42 4.4 Summary..........................................................................................................................48 5 Process design and application test.........................................................................................49 5.1 Nature of the ore..............................................................................................................49 5.2 Process design..................................................................................................................50 5.3 Test results and analysis.................................................................................................. 51 5.4 Summary..........................................................................................................................52 6 Conclusions and prospects.......................................................................................................53 6.1 Main conclusions.............................................................................................................53 6.2 Work prospects................................................................................................................54 References Appendix Author’s Resume Acknowledgements Thesis Data Collection I 图清单 图序号图名称页码 图 1.1 三锥角旋流器 2 Fig. 1.1Hydrocyclone with three cone angle2 图 1.2几种锥体结构 3 Fig. 1.2Several cone structures 3 图 2.1 旋流器结构及液流双螺旋模型6 Fig. 2.1 Hydrocyclone structure and liquid flow double helix model6 图 2.2旋流器内流体流动的二维迹线图6 Fig. 2.2 Two-dimensional trace of fluid flow in the hydrocyclone6 图 2.3 旋流器二维示意图8 Fig. 2.3 Two-dimensional schematic of hydrocyclone8 图 2.4 旋流器内颗粒受力示意图11 Fig. 2.4Schematic diagram of force on particles in a hydrocyclone11 图 2.5 速度矢量方向示意图12 Fig. 2.5Schematic diagram of velocity vector direction12 图 2.6颗粒运动示意图 13 Fig. 2.6 Particle motion diagram13 图 3.1 旋流器二维示意图及母线方程20 Fig. 3.1 Two-dimensional structure of hydrocyclone and bus equation20 图 3.2网格化分21 Fig. 3.2 Meshing21 图 3.3 网格质量22 Fig. 3.3 Mesh quality22 图 3.4 模拟策略22 Fig. 3.4Si