搅拌机布置方式对生化池流场的影响及优化

Influence and optimization of mixer′s arrangement of flow field of anoxic pool

针对某缺氧池混合液搅拌效果的好坏不仅与设备自身设计有关,更受到搅拌机布置方式影响的问题,研究搅拌机布置方式对生化池流场的影响.基于Star-ccm+虚拟仿真平台,对缺氧池及搅拌机区域进行多面体网格划分,采用k-ε湍流模型进行全流场数值模拟,剖析池内流场物理结构.根据搅拌机搅拌形成的环流布局,设计整体推流和分布推流2种布置方式,最终获得最佳安放角度和位置.计算结果表明:该缺氧池采用整体推流能有效减小低速区域面积,提高平均搅拌速度;当2台搅拌机与壁面呈一定角安放时,更利于推流的扩散和死角区域的改善.根据优化结果对现场进行布置,试验结果与数值模拟接近.因此,采用多面体网格计算,具有较好的收敛速度和计算精度,可为生化池流场中搅拌机布置提供参考.

Aiming at the problem that the mixing effect of the mixed liquor in an anoxic tank is related to the design of the equipment and affected by the arrangement of the mixer,the influence of arrangement of mixer on the flow field of anoxic pool was studied.Based on the Star-ccm+virtual simulation platform,the anoxic pool and the mixer′s domain were divided into polyhedral grids,and the k-εturbulence model was used to conduct the numerical simulation for the full pass and analyze the physical structure of the flow field in the pool.According to the circulation layout formed by mixer,the two layout modes were designed,namely,the overall push flow and the distributed push flow,so as to obtain the optimal placement angle and position.The results show that the anoxic pool can effectively reduce the area of low speed area and increase the average stirring speed by adopting the whole pushing flow.When two agitators are placed at a certain angle to the wall surface,the diffusion of pushing flow and the improvement of dead corner area are more favorable.According to the optimization results,the experimental results are close to the numerical simulation.Therefore,the polyhedral mesh calculation is adopted,which has a good convergence rate and calculation accuracy,providing a reference for the layout of agitators in the flow field of biochemical pool.