Discussion On A Hydraulic Design And Optimization Method Of Submersible Mixer

Submersible mixer is an important sewage treatment process in biological wastewater treatment,which has received extensive attention and application in daily production.The commonly used energy-consuming devices are fans,pumps and submersible mixers.As an important sewage treatment equipment,the submersible mixer works by mixing the sewage to make the activated sludge and sewage fully biochemical reaction,preventing the activated sludge deposition phenomenon in the biological pool,and the impeller performance of the submersible mixer directly measures the water quality.Whether or not.At present,domestic scholars' research on the submersible mixer impeller is limited to the number of impeller blades and the shape of the impeller.The research on the airfoil of the submerged mixer impeller blade has produced little results.At the same time,there is still a lack of effective diving in China.Hydraulic design method for mixer impeller blades.Therefore,in-depth study on the blade airfoil and hydraulic design method of the submersible mixer impeller plays an important role in the structural design and optimization of the submersible mixer,and provides a solid theoretical foundation and energy-saving power for the sewage treatment industry.The research contents and results of this paper are as follows:1.Create a mesh model that combines a polyhedral mesh with a prismatic mesh.Based on the standard k-? turbulence model,the constant value simulation of the submersible mixer was carried out,and the correctness of the numerical simulation method was verified by the thrust test.In this way,the numerical calculation method of the submersible mixer is obtained,which lays a foundation for the research of this paper.2.The hydraulic design method of axial flow pump—the arc thin airfoil chart design method is proposed to design the submersible mixer impeller,and a three-dimensional hydraulic model of the initial submersible mixer impeller is designed.Based on CFD research method and standard ring The test tank was studied for its stirring effect and the external characteristics under the axial flow pump installation.The results show that the stirring effect is good,but it still needs to be optimized.3.The optimization method of the velocity loop distribution in the axial flow pump design is applied to the airfoil optimization of the submersible mixer impeller,and the relationship between the loop distribution and the leaflet type inlet and outlet angle is obtained.4.Based on the optimization design method of velocity loop distribution,the airfoil model of the initial submersible mixer impeller hydraulic model is optimized,and a series of three-dimensional hydraulic models with different inlet and outlet angles are obtained.Based on CFD research method and standard annular test pool,The numerical calculation is carried out,the circulation distribution and the various hydraulic parameters are statistically calculated,and finally the circulation distribution curve under the best stirring effect is obtained.5.Based on the optimal circulation distribution curve,the existing submersible mixer impeller is optimized.According to the CFD post-processing results,the optimized mixing performance of the existing submersible mixer is significantly stronger,and the speed loop is verified.The accuracy of the volume distribution curve.