颗粒旋转强化废水旋流分离机理研究

Three dimensional cyclone separation field widely exists in the waste water pollutants treatment process, revolution and rotation of the suspended particles in the rotating flow field has a huge impact to the separation process. In this project, the three dimensional rotational motion of the suspended particles in the cyclone separation field is treated as the research object, the revolution information, separation performance information and flow field in the cyclone separation field were obtained by CFD flow field simulation technology and V3V (Volumetric three-velocimetry measurements) flow field test technology. High speed video camera shooting technology is used to study the 3D rotational motion of suspended particle with different shape in the cyclone separation field. After analyzing and summarizing experiment conclusion, collaborative variation law between the three-dimensional rotation characteristics of suspended particles and 3D rotating flow field and it's mechanism to cyclone separation performance were explored and a suitable treatment technology for waste water containing solid inorganic particles by controlling particles rotation and equipment were explored. The completion of this project will proviede a new thinking way to recognize cyclone separation mechanism and a new method to regulate the cyclone separation performance.

废水污染物分离处理工艺流程中广泛存在着三维旋流分离场，悬浮颗粒在旋流分离场中的自转和公转运动对分离处理过程有着巨大影响。本课题将悬浮颗粒在旋流分离场中的三维旋转运动作为研究对象，通过CFD流场模拟技术和V3V（体三维速度测量系统）流场测试技术得到典型操作工况下的流场信息、分离性能信息和悬浮颗粒公转信息等；通过三维高速摄像技术研究旋流分离场中不同物性悬浮颗粒、不同结构旋流器在典型操作工况下的旋流运动规律，探索悬浮颗粒维旋转特性随三维旋转流场的协同变化规律及其对旋流分离性能的作用机理；开发出一种基于调控颗粒旋转的适用于处理含固态无机颗粒污染物废水的的旋流控制技术和设备。本项目的完成将为学者认识废水旋流分离机理提供一个新的思路，为调控旋流分离性能提供一种新的方法。

针对多相流旋流分离处理工艺流程中广泛存在的三维旋流分离场，微粒自转和公转运动对分离工艺处理效果的影响。本项目开展了旋流分离流场的模拟和测试实验研究，以及颗粒自转的测试和理论分析研究。采用一维和二维高速摄像技术测量出了旋流分离场中颗粒的自转和公转速度，采用CFD流场模拟技术和体三维流场测速仪V3V测定三维流场结构。探索得出颗粒自转速度受分离处理工艺过程的操作工况、物料颗粒形状系数、流场中湍流、颗粒在流场中的位置的综合影响，颗粒自转速度既具有规律性也表现出随机性；三维旋转流场模拟和测试发现流体的切向速度和轴向速度随进口流速的增加而增大，切向速度和径向速度的最大值均出现在准自由涡和强制涡的交界面附近；溢流出口-进口压降越小，切向速度越大， 轴向速度越小，主分离区的径向速度越大。根据实测的流场分布，对Bloor & Ingham 流函数模型进行了修正，建立了对应的修正公式。结合Bloor & Ingham修正公式和旋流分离场中的颗粒进行受力分析，建立了基于流场耦合的颗粒自转预测数学模型。颗粒自转与公转产生了作用于颗粒上质点的周期性强耦合离心力，有助于含油废催化剂颗粒孔隙中的污染物向外迁移，从而提高旋流分离工艺的除油效率。