Influence of wastewater mixer setting angle on flow field in sewage treatment pool
ZHANG Zhi1, ZHEN Yuan1*, JIANG Jieqing2, LI Chengyi1
1. College of Energy and Electrical, Hohai University, Nanjing, Jiangsu 210098, China; 2. East China Yixing Pumped Storage Power Co. Ltd., Yixing, Jiangsu 214205, China
Abstract：An unreasonable setting angle can result in a wastewater mixer to consume much more po-wer. Bearing this problem in mind, three-dimensional turbulent fluid flows in a sewage water treatment pool with two wastewater mixers at various setting angles were simulated using Fluent software to optimize mixer design and reduce sludge deposition at the pool bottom due to low water velocity. At first, the three-dimensional fluid domain model was established in UG software, then the steady fluid flow field was calculated in unstructured tetrahedron grids based on the N-S equations, standard k-ε turbulence flow model and SIMPLEC algorithm. The average velocity and velocity distribution within the pool were compared across various setting angles. Consequently, flow mixing effect was assessed by employing gray correlation method in terms of low velocity zone occurrence rate at the pool bottom. At the same time, the relationship between vortex structure and mixing energy consumption was studied. The results show that when the angle is 50° the average fluid velocity at the bottom is increased by 17.6%, the volume-averaged velocity is increased by 6%, and the low velocity zone occurrence rate at the bottom is reduced by 12%, suggesting the best transporting and mixing effect. Additionally, the vortex phenomenon has a significant impact on stirring effect. The smaller the number of vortices and the larger the scale of a single vortex, the lower the energy consumption and the more sTab. the fluid flow, the better the mixing effect. Altering the setting angle of a wastewater mixer can improve fluid flow pattern in a sewage water treatment pool, suppress sludge deposition and reduce energy consumption of vortex, eventually to achieve an aim with advanced transporting and mixing effect.
张智,郑源*,蒋洁青,李城易. 污水搅拌器摆放角度对流场性能影响[J]. 排灌机械工程学报, 2020, 38(3): 272-276.
ZHANG Zhi,ZHEN Yuan*,JIANG Jieqing,LI Chengyi. Influence of wastewater mixer setting angle on flow field in sewage treatment pool. Journal of Drainage and Irrigation Machinery Engin, 2020, 38(3): 272-276.
