【作者】 董勇；

【导师】 李文英；

【作者基本信息】 太原理工大学 ， 机械电子工程， 2009， 硕士

【摘要】 煤泥水处理是一个固-液分离和固-液回收的过程。为了解决煤泥水的流失浪费和减轻排放出的煤泥水对环境的污染,选煤工作者们都在努力寻求一种可行、高效的办法,尤其是一种能对这些排放出的煤泥水进行有效处理的新型设备。另外,在污水处理方面,现在污水处理厂的活性污泥分离浓缩通常都是使用常规的重力沉降装置,即沉淀池实现固液分离。其优点为处理量大,浓缩、分离效果也很好,但存在占地面积过大,污水停留时间长,处理效率低等不足,污泥回流消耗也很大。针对以上污水处理的不足之处,应该在污水进入沉淀池之前先利用水力旋流器对污水进行分离浓缩,这样会提高污水含泥量和降低相应循环流量,减少沉淀池底泥的负荷量,减轻沉淀池负担和减少沉淀池面积。鉴于以上情况,我们选择了利用旋流分离原理来完成作业的固-液旋流分离器。固-液旋流分离器是一种离心分离装置,是利用不互溶介质间的密度差而进行离心分离的。CFD数值模拟作为一种新的研究方法,利用它能够充分地认识流体机械内部的流动情况,可以缩短设计周期、减少设计费用。本文采用CFD软件中的RNG K-ε湍流模型,基于控制体积法实现对输送方程的离散化,应用SIMPLE算法,采用基于两相流的混合模型(mixture model)对固-液旋流分离器内部流场进行了数值模拟。通过对模拟计算结果分析研究,得到了固-液旋流分离器内压力场、速度场和固相浓度等流场特性参数的分布规律,同时分析了流量、转速、分流比等对分离效率的影响,分析了固-液旋流分离器内部流场的分布规律和固-液两相流的分离特性。在模拟计算的基础上,结合理论分析,对固-液水力旋流器的旋流腔、旋转栅结构、底流口直径及溢流管伸入长度等相关部件结构参数进行优选。在对各种固液分离设备进行研究的基础上,分析了其分离机理、结构特点、优缺点等,在此基础上对固-液旋流分离器进行结构设计。研究物性参数、操作参数对分离器分离性能的影响,确定合理的结构方案。通过对固-液旋流分离器内部流场的深入研究,掌握流体的运动规律,能够为今后的结构设计和尺寸优化提供理论指导。为从理论上对旋流器进行深入研究、设计高效分离设备提供了一条新途径。更多还原

【Abstract】 The slime water treatment is a solid-liquid separation and solid-liquid recovery process. In order to solve the loss and waste of slime water and reduce the pollution of slime water discharged to environment,coal separation workers were trying to find a viable and efficient approach. In particular,a kind of new equipment is found that it can deal with the slime water effectively discharged.In addition, in the sewage treatment,the conventional gravity sedimentation device is used for separation and concentration of the activated sludge in the sewage treatment plant, that is the sedimentation pools to achieve solid-liquid separation. Its advantage is the large handling capacity, good result of concentration and separation,but there is some shortcomings in large floor space,long stay time of sewage water,low efficiency in sewage treatment, large sludge circumfluence consuming.Aim at the shortcomings in Sewage treatment, Sewage water should be separated and concentrated before entering the sedimentation pool through using hydro cyclone.It will enhance the sludge volume of sewage water, to low the cycling flow rate, to reduce loading sludge volume in the Bottom of the Sedimentation pools, to reduce the burden of the Sedimentation pools and decrease the area of sedimentation pools.In light of the above, we have chosen solid-liquid hydro cyclone using cyclone-separating principle to complete the work. The solid-liquid hydro cyclone is a kind of Centrifugal separating device and separation is achieved using the difference of the magnitude of the density.In this paper, RNG K-εturbulence model in CDF software is selected. The discrimination method of transport equation based on Control volume method is implied. SIMPLE algorithm is implied. Internal flow field of the solid-liquid hydro cyclone was simulated through selecting mixture model based on two-phase flow. Through the analysis of simulation results, distribution of flow field feature parameters were obtained, such as pressure field, velocity field and the solid-phase concentration. At the same time, impact of flow rate, speed and diffluent ratio to separation efficiency was analyzed. Distribution of internal flow field and Solid-liquid two-phase flow characteristics of the separation was analyzed. At the basis of simulation and theoretical analysis combined the structure parameters of the Cyclone chamber, rotating pale, diameter of down-flow outlet and the insertion depth overflow tube was optimized On the solid-liquid hydro cyclones. At the basis of research to a variety of solid-liquid separation equipment research,the Separation mechanism and Structural characteristics advantages and disadvantages was analyzed. On this basis, structural design of the solid-liquid hydro cyclones was achieved.The impact of physical parameters and operation parameters to separation performance was studied. The reasonable structural program was determined. Through Further studies to the internal flow field of the solid-liquid cyclone separator, the movement regular of the fluid was grasped and this can provide theoretical guidance to the structural design and size optimization in the future. This can provide a path for the purpose of the depth-study to the solid-liquid cyclone separator theoretically and the design of the high efficient separation equipment.更多还原