中心传动浓密机进料井结构与流场研究

发布时间：2018-06-12 13:20

本文选题：浓密机进料井 + FLUENT数值模拟　；参考：《天津大学》2015年硕士论文

【摘要】：浓密机是一种重要的固液分离设备,主要用于湿式选矿中精、尾矿的脱水。浓密机进料井的结构对浓密机进料井内的流动形态、悬浮液的絮凝特性有重要影响,进而影响浓密机的固液分离效率,进料井结构设计与优化研究具有一定的理论意义和重要的工程应用价值。本文采用计算流体力学(CFD)和实验方法相结合,对传统进料井内的絮凝特性和流动形态进行了研究。结果表明,悬浮液和絮凝剂分股混合能够有效改善进料井内悬浮液的絮凝特性,两股物料能够相互作用,增强絮凝效果。絮凝剂注入方向和注入位置是影响进料井絮凝效果的重要因素,絮凝剂与悬浮液交叉流动的效果好于对流流动,交叉流动能够使悬浮液和絮凝剂充分接触,有利于絮凝剂和固体颗粒的混合和扩散。通过数值模型模拟了四种传统进料井内部的迹线分布、固相体积分数分布和出口平面速度分布,结果表明,折流板可以有效降低物料流出进料井的速度。增加折流板后,单口切向进料和双口切向进料出口平面的最大速度分别为进料速度的48%和57%,而且单口切线进料井有折流板可以有效地改善物料分布的均匀性和对称性。针对传统进料井难以达到既要物料分布对称性好,又要降低物料的流动速度的效果,本文提出了一种新型的浓密机进料井结构,该结构简单,不需要提供任何外动力,节约能耗。采用数值模拟方法对新型进料井的迹线分布、固相体积分数分布、出口平面速度分布进行研究。结果表明,新型浓密机进料井结构在不同的进料速度下,能够有效减小进料悬浮液的流动速度,均匀分布物料,使物料从进料井的各个方向与径向呈一定角度流出,延长物料到达溢流堰的时间。与传统进料井相比,新型进料井对操作参数的变化具有较好的适应性。本文的研究结果可为浓密机的设计与优化提供参考和依据。
[Abstract]:Thickener is an important solid-liquid separation equipment, mainly used for dehydration of fine and tailings in wet dressing. The structure of the thickener feed well has an important effect on the flow pattern and flocculation characteristics of the suspended liquid in the thickener feed well, thus affecting the solid-liquid separation efficiency of the thickener. The research on structure design and optimization of feed well has certain theoretical significance and important engineering application value. In this paper, the flocculation characteristics and flow patterns in traditional feed wells are studied by using computational fluid dynamics (CFD) and experimental methods. The results show that the mixing of suspension and flocculant can effectively improve the flocculation characteristics of the suspension in the feed well, and the two materials can interact with each other to enhance the flocculation effect. The direction and position of flocculant injection are the important factors affecting the flocculation effect of feed well. The effect of cross flow between flocculant and suspension is better than that of convection flow, and cross flow can make the suspension and flocculant come into full contact with each other. It is advantageous to the mixing and diffusion of flocculant and solid particles. The distribution of trace line, solid phase volume fraction and outlet plane velocity in four traditional feed wells are simulated by numerical model. The results show that the baffle plate can effectively reduce the velocity of material flowing out of feed well. When the baffle plate is added, the maximum velocity of single tangential feed plane and double tangential feed outlet plane is 48% and 57% of the feed velocity, respectively. Moreover, the single tangent feed well with baffle plate can effectively improve the uniformity and symmetry of material distribution. In view of the fact that it is difficult for traditional feed wells to achieve the effects of good symmetry of material distribution and reducing the flow rate of materials, a new type of thickener feed well structure is proposed in this paper. The structure is simple and does not need any external power. Save energy. The distribution of trace line, solid phase volume fraction and outlet plane velocity of the new feed well are studied by numerical simulation method. The results show that the structure of the new type thickener feed well can effectively reduce the flow velocity of the feed suspensions and distribute the materials evenly under different feed speeds, and make the materials flow out at certain angles from each direction and radial direction of the feed well. Extend the time for material to reach overflow Weir. Compared with the traditional feed well, the new feed well has better adaptability to the change of operating parameters. The results of this paper can provide reference and basis for the design and optimization of thickener.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD462

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