W型反射板水力分级机分级性能研究.pdf

万方数据 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 W 型反射板水力分级机分级性能研究型反射板水力分级机分级性能研究 Research on Classification Perance of W-type Reflective Plate Hydraulic Classifier 作者曹井振入学时间2017 年 9 月 导师张悦刊职称副教授 副 导 师孙炳泉职称教授级高工 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）机械工程 答辩日期2020 年 5 月提交日期2020 年 6 月 万方数据 学位论文使用授权声明学位论文使用授权声明 万方数据 学位论文原创性声明学位论文原创性声明 万方数据 学位论文审查认定书学位论文审查认定书 万方数据 摘摘要要 微细颗粒分级对有效提升矿产资源高附加值具有重要工程应用价值。水力分级机以优 异的性能在分离科学领域得到了广泛的应用。但是由于现有分级机分离提取的粉体粒度 大，粉体间互相夹杂导致粉体质地不纯，不能满足工业对精细粉体的要求。本文提出了一 种带有 W 型反射板、切向进料的新型水力分级机，采用理论计算、数值模拟、实验室测 试和工业运行验证方法，对分级机流场及分离性能进行了研究，结果表明新型分级机可有 效提高分级精度和分级效率，研究成果对揭示分级机分级机理具有一定的参考价值。 应用 Fluent 软件对Φ200 mm W 型反射板分级机流场进行了数值模拟，模拟结果表明 相比于传统分级机， 新型 W 型分级机增加了切向进料结构， 减缓了下降物料与上升顶水的 对冲作用，提高了流场的稳定性；与传统分级机不同，新型分级机在入料管底部加入了一 个 W 型反射板，料浆经过 W 型反射板的反射作用使料浆二次折返，与上升水流混合形成 干涉沉降，有利于分级腔内矿浆悬浮床层的形成，从而提高分级精度和分级效率。研究表 明，适当提高进料速度有利于料浆的螺旋下降，有利于分级区域的流场稳定，从而可以有 效提高分级精度，但当进料速度过高时，高速下降的料浆会扰乱分级腔的流场。适当增加 进水速度，可以降低分级机内部流场的紊乱程度，有利于下降料浆有效分层，继而提高分 级性能，但当进水速度过高时，反而会降低分级分选效果。适当的入料管插入深度可以增 加分级腔分级区和沉降区的分级面积，提高分级精度。合适的 W 型板结构尺寸，有利于料 浆有效的抛射分层，有利于形成稳定的料浆悬浮床层，提高分级精度和分级效率。 试验研究表明在一定范围内，当进料速度增大时，分级性能明显提高，当进料速度 为 1.2m/s 时，溢流中小于 45μm 以下颗粒分级效率可达 56.62，产率可达 33.18，但当 进料速度超过 1.2m/s 时，高速下降的料浆会扰乱分级腔的流场稳定。适当增加顶水速度， 可以提高分级性能。当顶水速度为 0.9m/s 时，溢流中小于 45μm 以下颗粒分级效率可达 66.71， 产率可达 36.32； 合适的进料浓度可以减少物料之间由于粘滞力的作用而发生团 聚现象，当进料浓度为 25时，溢流中小于 45μm 以下颗粒分级效率可达 67.46，产率可 达 35.15；进料管插入深度影响料浆进入分级腔内的位置，插入太浅导致物料未经有效分 级进入溢流，增加物料的分级错配率，插入太深使得反射板和进水腔间形成狭窄空间，导 致此区域内湍动能增加，造成分级紊乱。W 型反射板结构尺寸影响物料的折返抛射距离， 直接影响颗粒在流场内的停留时间，进而影响分级精度。经综合对比，得到了优化的最佳 结构参数和操作参数组合方案进料速度为 1.2m/s，顶水速度为 0.9m/s，进料浓度为 25， 入料管插入深度为 350mm，W 型反射板与分级腔间隙为 25mm。 依据研究结果， 针对某磁铁矿粉分级具体要求， 设计开发了 W 型反射板双顶水三产品 水力分级机，并进行了工业运行试验，经过验证，溢流产率可达 47.49，分级效率达到 64.9，较传统分级机分别提高了 8.62 个百分点和 11.34 个百分点。 关键词关键词水力分级机；W 型反射板；切向入料口；数值模拟；试验研究；分级性能 万方数据 Abstract The classification of fine particles has important engineering application value for effectively enhancing the high added value of mineral resources. The hydraulic classifier has been widely used in the field of separation science with excellent perance. However, the powders separated and extracted by the existing classifiers have a large particle size, and the powders are mixed with each other, resulting in impure powder texture, which cannot meet the industrial requirements for fine powders. This paper presents a new type of hydraulic classifier with W-shaped reflector and tangential inlet. The s including theoretical analysis, numerical simulation, laboratory testing and industrial operation verification s are used to study the flow field and separation perance of the classifier. The results show that the new classifier can effectively improve the classification accuracy and classification efficiency. The research results have certain reference value for revealing the classification mechanism of the classifier. The Fluent software is used to numerically simulate the flow field of the Φ200mm W-type reflector classifier, and the simulation results show that compared with traditional classifier, the new W-type classifier can lower the hedging effect of falling materials and rising water, and improve the stability of the flow field,attributing to the tangential feeding structure. Different from the traditional classifier, the new classifier adds a W-shaped reflecting plate at the bottom of the feeding tube. The reflection of the slurry make it reenter and mix with the rising water again ,and the interference sedimentation is conducive to the ation of suspension bed of slurry in the grading cavity , thereby improving classification accuracy and efficiency. Studies have shown that appropriately increasing the feed rate is conducive to the spiral decline of the slurry and the stability of the flow field in the classification area, which can effectively improve the classification accuracy.But if the feed rate is too high,the rapidly downward slurry will disturb the flow field. Properly increasing the inlet water speed can reduce the disorder of the flow field inside the classifier, which is conducive to the effective stratification of the slurry and improve the classification perance. However, when the inlet water speed is too high, the classification and separation effect will be reduced. Appropriate insertion depth of the feed pipe can increase the classification area of the classification area and the settlement area of the classification cavity and improve the classification accuracy. With appropriate structure size of the W-shaped reflector, the slurry can be effectively ejected and layered, which is conducive to a stable slurry suspension bed and improve the classification accuracy and efficiency. Experimental research shows that within a certain range, when the feed speed is increased, 万方数据 the classification perance is significantly improved. When the feed speed is 1.2m/s, the classification efficiency of particles below 45 μm in the overflow can reach 56.62, and the yield can reach 33.18, but when the feed speed exceeds 1.2m/s, the slurry falling at high speed will disturb the flow field stability of the classifying cavity. Properly increasing the inlet water speed can improve the classification perance. When the inlet water velocity is 0.9m/s, the classification efficiency of particles below 45μm in the overflow can reach 66.71, and the yield can reach 36.32.Appropriate feed concentration can reduce the occurrence of agglomeration caused by viscous forces between materials. When the feed concentration is 25, the classification efficiency of particles below 45μm in the overflow can reach 67.46, and the yield can reach 35.15. The depth of the insertion tube affects the initial position of the slurry when it enters the classification cavity. If the insertion depth is too shallow,the material will enter the overflow without effective classification, leading to increament of the classification mismatch rate. If the insertion depth is too deep, the space between the reflector and the water inlet cavity will be narrowed, resulting in increased turbulent kinetic energy in this area and causing classification disorder. The structural size of the W-shaped reflector affects the repulsive throw distance of the material, directly affects the residence time of particles in the flow field, and then affects the classification accuracy. After comprehensive comparison, the optimal combination of optimal structural parameters and operating parameters is obtained the feed speed is 1.2m/s, the inlet water speed is 0.9m/s, the feed concentration is 25, and the feed pipe insertion depth is 350mm. The gap between the W-shaped reflector and the classification cavity is 25mm. Based on the research results and according to the specific requirements for the classification of a certain magnetite powder, a three-product hydraulic classifier with W-type reflector and double-inlet was designed and developed, and the industrial operation test was conducted. After verification, the overflow yield can reach 47.49, and the classification efficiency reaches 64.9, which is 8.62 and 11.34 higher than those of the traditional classifier respectively. Keywords Hydraulic classifier; W-shaped reflector; Tangential inlet; Numerical simulation; Experimental research; Classification perance 万方数据 目目录录 图清单....................................................................................................................................................................I 表清单..................................................................................................................................................................V 变量注释表.......................................................................................................................................................VI 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....................................................................................................................................5 2理论基础及系统设计............................................................................................................... 6 2.1W 型反射板分级机结构及分级原理.............................................................................6 2.2数值模拟理论基础....................................................................................................... 15 2.3本章小结....................................................................................................................... 18 3W 型分级机分级性能数值模拟研究.....................................................................................19 3.1几何建模和网格划分................................................................................................... 19 3.2设定模拟参数............................................................................................................... 21 3.3数值模拟结果及分析................................................................................................... 22 3.4本章小结....................................................................................................................... 37 4分级机分级性能试验研究..................................................................................................... 39 4.1总体试验设计............................................................................................................... 39 4.2对比试验....................................................................................................................... 41 4.3单因素试验................................................................................................................... 42 4.4正交试验....................................................................................................................... 49 4.5工业运行试验............................................................................................................... 53 4.6本章小结....................................................................................................................... 55 5结论与展望............................................................................................................................. 56 5.1主要结论....................................................................................................................... 56 5.2工作展望....................................................................................................................... 57 参考文献 作者简历 致谢 学位论文数据集 万方数据 Contents List of Figures.................................................................................................................................I List of Tables..................................................................................................................................V List of Variables...........................................................................................................................VI 1Introduction..............................................................................................................................1 1.1Background of the Research............................................................................................1 1.2TheAim and Significance of Dissertation.......................................................................1 1.3Research Actuality...........................................................................................................2 1.4Main Research Content....................................................................................................5 2Theoretical Basis and System Design.....................................................................................6 2.1Basic Classification Principles of W-type Reflective Plate Classifier.............................6 2.2Numerical Simulation Theory........................................................................................15 2.3Summary........................................................................................................................18 3Numerical Simulation of W-type Classifier.........................................................................19 3.1Modeling and Meshing..................................................................................................19 3.2Setting simulation parameters........................................................................................21 3.3Numerical simulation results and analysis.....................................................................22 3.4Summary........................................................................................................................37 4Experimental Study on Grading Perance of Classifier..............................................39 4.1General Experimental Design........................................................................................39 4.2Contrast Testing.............................................................................................................41 4.3Single Factor Test.......................................................................................................... 42 4.4Orthogonal Testing.........................................................................................................49 4.5Industrial Operation Test................................................................................................53 4.6Summary........................................................................................................................55 5Conclusions and Prospects....................................................................................................56 5.1Main conclusions...........................................................................................................56 5.2Prospects........................................................................................................................57 References Author’s Resume Acknowledgements Thesis Data Collection 万方数据 I 图清单图清单 图序号图名称页码 图 2.1W 型反射板分级机结构示意图 6 Fig.2.1Schematic diagram of structure of W type reflector classifier6 图 2.2球形固体颗粒在入料管结构中旋转沉降及受力图8 Fig.2.2 Rotating settlement and force diagram of spherical solid particles in the feeding tube structure 8 图 2.3固体颗粒在 W 型反射板上折射沉降图9 Fig.2.3Refraction settlement of solid particles on w-shaped reflector plate9 图 2.4 固体颗粒在 W 型反射板峰顶处受力图 9 Fig.2.4 Force diagram of solid particles at the peak of w-shaped reflective plate 9 图 2.5固体颗粒在 W 型反射板峰坡处受力图10 Fig.2.5Force diagram of solid particles at peak slope of w-shaped reflective plate1