基于Y型溢流管结构的疏浚旋流器分离机理研究

In separation of channel dredging slurry, application of traditional hydrocyclone often leads to low efficiency and processing capacity of fine particles due to the multi-component and wide range of operating conditions. The project aims to develop a new kind of hydrocyclone base on Y-vortex and study its separating mechanism.. With screw opening on the sidewall, the new design can eliminate the short-circuit flow and fluid instability caused by the random deviation of the air column. Therefore, the separation space is enlarged and the separation efficiency can be improved effectively. Based on Reynolds stress model, mixed model and discrete phase model, the mathematical model of the new hydrocyclone is established to simulate the fluid characteristics of the single phase and multi-phase flow in it. Combining PIV technology and the experimental results, the model is modified and improved in order to reveal the law of distribution of velocity、pressure and turbulent kinetic energy under different conditions. . By using theoretical analysis,numerical simulation and experimental measurement simultaneously, the research on the intensified separating mechanism of the hydrocyclone could not only enrich the conventional rotary flow field theory, but .also lay theoretical foundation for the optimizing design of the industrialized hydrocyclone.

航道疏浚泥水具有组分多、工况变化大的特点，采用传统旋流器分离存在着处理量小、微细颗粒分离效率低的难题。本项目拟研究基于Y型溢流管结构的旋流器分离机理。采用Y型溢流管结构并在其侧壁开螺旋孔，可有效消除由于短路流造成的溢流跑粗和空气柱随机偏移造成的流体失稳，达到提高分离效率及运行稳定性和增大有效分离空间的目的。通过包含雷诺应力模型、混合模型和离散相模型的数值模拟方法，建立适宜于疏浚泥水分离的旋流多相分离数学模型，并对旋流器内液相和固-液及固-液-气多相流进行数值模拟。结合三维粒子图像测速技术，根据不同条件下的性能试验，对分离模型进行修正，探索不同工况条件下速度、压力、湍动能的分布特点，研究多组分颗粒群在旋转流场中的干涉沉降分离机理。项目采用理论分析、数值模拟与试验测量并举研究Y型溢流管结构强化分离的机理，研究结果不但可以丰富旋转流理论，而且还可以为工业优化设计高精度旋流器提供理论基础。

针对传统旋流器分离微细颗粒时存在的处理量小、分离效率低的难题，本项目通过研究旋流器内部涡流形成及稳定性机理，提出了Y型溢流管、渐扩锥形进料体、钟型溢流管等有效抑制涡流、消除短路流的结构改良措施；采用钟型溢流管加固棒的结构有效抑制空气柱；探索了双溢流管结构的多产品旋流器并应用于微细颗粒的精细分级，从而实现了增强旋流器内部流场的稳定性、提高分离效率的研究目标。结合CFD数值模拟和PIV技术，揭示了新型设备内部流体的速度、压力、湍动能分布规律，探明了多组分颗粒群的干涉沉降分离机理，丰富了传统的旋转流分离理论。结合理论研究、数值模拟和试验测量，建立了适宜于多变工况下分离旋流器的数学模型，为新型旋流器的优化设计及推广应用奠定了理论基础。