Optimization Design Of Baffle And Weir For Rectangular Settling Tank

As the common solid-liquid separation process,the rectangular settling tank plays an important role in the treatment of water supply plant.However,there are problems such as uneven distribution of flow and floating of the tail sediment during the operation.With the improvement of the urban water plant construction,the optimization of the settling tank is more of a change in the existing pool type,but the relevant content specification has not been clearly defined.In order to solve the problems of uneven distribution of corridor flow and flotation of flue in the runoff pond,this paper takes the actual run of the rectangular settling tank in the Wuhan Zhuankou Water Plant and the Anlu NO.3 water plant as the research object.Rhino software was used for 3D modeling;The numerical simulation of the flow state in the settling tank was carried out by Fluent software.Through the analysis of the simulation results,the influencing factors of the treatment effect are found out,and the optimal design of the rectangular baffle and the runoff weir are designed.The main conclusions are as follows:(1)The effect of diversion damper on the uniformity of water distribution the Zhuankou Water Plant is not obvious,and the improvement of baffle is imperative.(2)Through the simulation analysis of the length L,angle ? and installation position D of the baffle,the order of influence of each factor on the distribution uniformity is as follows: L >> D>?;And the optimization scheme of the parameters of the diversion baffle is as follows: L = 2.0m,? = 94 ° and D = 2.2m.Under the optimization scheme,the uniformity index of the corridor is 0.964,compared with the current situation increased by 9.9%.(3)The length and arrangement of the weir in the rectangular settling tank have a great influence on the treatment effect.When the water flow in the settling tank is constant,the larger the length of the weir is,the more stable the flow is and the higher the floc removal rate is.When the water outlet is low,the setting of the vertical weir does not improve the removal rate of the floc.It is suggested to cancel the vertical overflow weir and optimize the finger weft length to 35 m.