旋流-静态微泡浮选柱旋流流场的数值模拟与试验测量

发布时间：2018-01-30 21:17

本文关键词： 旋流-静态微泡浮选柱旋流流场分选机理流体动力学数值模拟高速动态摄像三维轨迹　出处：《煤炭学报》2016年06期 　论文类型：期刊论文

【摘要】：针对旋流-静态微泡浮选柱进行了气-液两相流非稳态数值模拟,分析了旋流单元的流动特征及矿化方式,然后采用2台高速动态摄像机连用的方法,进行了气泡、颗粒在旋流流场下的三维运动轨迹及碰撞行为的测量,得出了与数值模拟相一致的结论。主要结论如下:在旋流单元,气、液两相的流动均以切向运动为主,锥上区域具有向心和向上的趋势,锥内区域具有离心趋势,锥下区域液相旋流向下运动;气、液两相具有轴向和径向速度差,切向速度虽然不具有明显相间速度差,但其在径向上的梯度极高;锥内区域气含率最高,在10%~13%,锥下区域气含率小于1%。旋流单元的分选作用以分离尾矿和分选中等粒级矿物为主,气泡与颗粒的矿化方式体现为绕轴心旋转过程中发生的轴向与径向的"逆流碰撞",锥下区域不具备矿化条件,旋流强度是影响该单元分选和分离效率的重要因素。
[Abstract]:The non-steady numerical simulation of gas-liquid two-phase flow was carried out for the swirl-static micro-bubble flotation column. The flow characteristics and mineralization mode of the swirl unit were analyzed, and then two high-speed dynamic cameras were used. The three-dimensional motion trajectory and collision behavior of bubbles and particles in the swirl flow field are measured, and the results are in agreement with the numerical simulation. The main conclusions are as follows: in the swirl flow unit, gas. The flow of liquid in both phases is mainly tangential, the area above the cone is concentric and upward, the region in the cone has a centrifugal tendency, and the liquid swirl moves downward in the region under the cone. Gas and liquid phase have axial and radial velocity difference, tangential velocity is not obvious phase velocity difference, but its radial gradient is extremely high. The regional gas holdup in the cone is the highest, and the gas holdup in the subconical region is less than 1. The separation of the swirl unit is dominated by the separation of tailings and the separation of medium-grained minerals. The mineralization of bubbles and particles is reflected in the "countercurrent collision" between the axial and radial direction in the process of rotating around the axis, and there is no condition for mineralization in the area below the cone. The swirl intensity is an important factor affecting the separation and separation efficiency of the unit.
【作者单位】：中国矿业大学化工学院;
【基金】：国家自然科学基金资助项目(51404264) 中央高校基本科研业务费专项资金资助项目(2014QNB16)
【分类号】：TD923
【正文快照】： 旋流-静态微泡浮选柱以其分选粒度细、选择性好等优点已在选煤和选矿上投入工业应用,其独特的过程原理及应用的广泛性使之广泛应用于金属及非金属矿物的分选[1-2]。该设备由柱选段、管流段及旋流段组成,将逆流、旋流、管流等多种不同的流态集成在一个柱体中去适配浮选过程中矿

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