涡流式混合反应器的研发及应用研究

发布时间：2018-03-21 15:56

本文选题：混合过程　切入点：涡流反应器　出处：《西安建筑科技大学》2013年硕士论文　论文类型：学位论文

【摘要】：涡流反应器是一种利用水力混合进行水处理的设备，其混合效果的好坏直接影响着水处理的效果。涡流反应器的优点主要是无需机械设备，节省动力费用，但缺点是混合效果差于机械混合。本文通过数值模拟对涡流式混合反应器的结构进行优化，并对其内部流场进行分析，使得反应器内部产生水力回流，以强化涡流反应器的混合效果。采用区域网格划分方法、利用结构化网格和非结构化网格相结合对反应器进行网格划分。因流动过程为紊态，，求解模型采用标准k模型，方程离散采用一阶迎风格式，流动过程采用离散相模型。控制参数的求解选用SIMPLEC算法，其他的保持默认数值和选项；代数方程的求解采用Guss-Seidle迭代法；通过建立常微分方程实现颗粒相的控制，并采用Gill算法。研究成果如下：（1）确定了反应器的结构和几何参数。反应器设计时主要采用了文献[27]中关于铁水混合反应的反应器，将其应用于水处理中，并通过模拟确定反应器径高比。模拟结果表明水流切向进入反应器后，与中心进入反应器的药物一起边旋转边向下流动，并且在喉口下端形成了近壁回流区，使得反应器的水力停留时间加长，提高了混合效率，减少了药物的投加量。反应器最佳几何参数是：d_2/d_1=(0.03～0.07)；d_2/d_3=0.13～0.2；d_420mm；d_5100mm；h_1=(0.2～0.3)d_1；h_2=(0.33～0.5)d_1；h_3=(0.2～0.5)d_3；h_4=(3～4)d_3。其中第一柱体直径为d_1，喉口直径为d_2，第二柱体直径为d_3，进水口直径为d_4，加药口直径为d_5，第一柱体高度为h_1，收缩椎体高度为h_2，扩张椎体高度为h_3，第二柱体高度为h_4。（2）确定了不同反应器容积时的边界流速。当反应器有效容积为12.3L时，最低入水速度为0.07m/s，最大入水速度为1.5m/s。当反应器大小为12.3m3和41.5m3时，也可得到良好的混合效果，证明该反应器改变体积后，可以处理不同的水量，但进水口直径不宜大于300mm。（3）探讨了该反应器用于实际工程的可行性。计算了当反应器有效容积为41.5m3时，钢筋混凝土材质和钢板材质的反应器的成本，计算得知钢筋混凝土材质制作成本为16.48万元，钢板材质制作成本为3.6万元。钢板材质的反应器制作费用比钢筋混凝土材质更经济，而且安装拆卸方便，但是钢板材质的反应器容易生锈，因此需做防锈处理或定期清洁。对该反应器进行了工程概预算结果表明，水处理费用为0.92元/d，比一般水处理费用1.2元/d低，节省了处理成本和能源。该反应器可广泛应用在不同领域，包括有实验室废水处理、饮用水处理、工业水处理、再生回用水处理、小型城镇水处理、化工领域等所有涉及固液混合和液液混合的场合。相比于现有的絮凝池和机械搅拌澄清池，该反应器其优点主要是：无搅拌设备、反应器内部产生水力回流、混合时间短、药物投加量少、混合效果好。
[Abstract]:Eddy current reactor is a kind of equipment for water treatment by hydraulic mixing, and its mixing effect directly affects the effect of water treatment. The advantage of eddy current reactor is that it does not need mechanical equipment and saves power cost. In this paper, the structure of eddy current mixing reactor is optimized by numerical simulation, and its internal flow field is analyzed. In order to enhance the mixing effect of eddy current reactor. In this paper, the method of regional mesh generation is adopted, and the reactor is meshed by the combination of structured grid and unstructured grid. Because the flow process is in an orderly state, the standard k model is used to solve the model and the first order upwind scheme is used to discretize the equations. The discrete phase model is used for the flow process, the SIMPLEC algorithm is used to solve the control parameters, the default values and options are kept for the others, the Guss-Seidle iteration method is used to solve the algebraic equations, and the particle phase control is realized by establishing ordinary differential equations. The research results are as follows:. The structure and geometric parameters of the reactor were determined. In the design of the reactor, the reactor about the mixed reaction of hot metal in reference [27] was mainly used in the water treatment, and the ratio of diameter to height of the reactor was determined by simulation. The simulation results showed that the flow direction was tangent into the reactor. Along with the drug entering the reactor, it rotates and flows down, and forms a near wall reflux zone at the lower end of the throat, which makes the HRT of the reactor longer, improves the mixing efficiency, and reduces the dosage of the drug. The best geometric parameters of the reactor are: 0. 02 / d1 / 0. 07 / d / 2 / d3 / d3 / 3 0.130.32 / d 420mm / d5100mm / h110.2n / 0.3d1d1h2/ 0.330.5d / 1h3h3/ 0.20.5d-1 / d / 3 / d / d / d / d / 3 / d / d / d / d / d / d / d / d / d / d / d / d / d / d _ 2 / d _ 3 / d _ 3 / d _ 3 / d _ 3 / d _ 3 / d _ 3 / d _ 3 / d _ 3 / d _ 3 / d _ 3 / d _ 3 / d _ 3 / d _ 3 / d _ 3 / d _ 3 / d _ 3 / d _ 3 / d _ 3 / d _ 3 / d _ 3 / d _ 3 / d _ 3 / d _ 2 / d _ 3 / d _ 3 / d _ 3 / d _ 2 / d _ 2 / d _ 2 / d _ 2 / d _ 2 / d _ 2 / d _ 2 / d _ 2 / d _ 2 / d _ 2 / d _ 2. The height is h3 and the second cylinder is h4. The boundary velocities of different reactor volumes were determined. When the effective volume of the reactor is 12.3 L, the minimum inlet velocity is 0.07 m / s, and the maximum inlet velocity is 1.5 m / s. When the reactor size is 12.3m3 and 41.5m3, the mixing effect can also be obtained. It is proved that the reactor can deal with different amounts of water when the volume is changed. However, the diameter of the inlet should not be greater than 300 mm. The feasibility of using the reactor in practical engineering is discussed. When the effective volume of the reactor is 41.5m3, the cost of the reactor with reinforced concrete material and steel plate material is calculated. It is found that the production cost of reinforced concrete material is 164800 yuan. The production cost of the steel plate material is 36,000 yuan. The production cost of the steel plate reactor is more economical than that of the reinforced concrete material, and it is easy to install and disassemble, but the steel plate material reactor is prone to rust. The result shows that the cost of water treatment is 0.92 yuan / d, which is lower than that of common water treatment cost 1.2 yuan / d, saving the treatment cost and energy. The reactor can be widely used in a variety of fields, including laboratory wastewater treatment, drinking water treatment, industrial water treatment, recycled water treatment, small town water treatment, Compared with the existing flocculation tank and mechanical stirring clarifier, this reactor has the advantages of no mixing equipment, hydraulic reflux in the reactor, and short mixing time. The drug dosage is less and the mixing effect is good.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU991.2

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