Numerical Simulation Of Structural Hydraulic Optimization In Flocculation Zone Of DENSADEG

DENSADEG is a combination of flocculation and sedimentation in one water treatment technology.It is widely used in water treatment engineering all over the world.DENSADEG is necessary to be simulated,because of no relevant design code in China.As one of the processing links of DENSADEG,the flocculation effect is affected by hydraulic conditions.Therefore,from the perspective of optimizing hydraulic conditions,the flocculation zone of high density clarifying tank is simulated.The flow pattern of flocculation zone in DENSADEG is simulated by numerical simulation.The turbulent kinetic energy dissipation rate is used as the evaluation index of flocculation.The DENSADEG with different scales are studied.The shape and size of guide tube,guide plate and installation position of DENSADEG are simulated respectively.The influence of the shape of the guide tube and some parameters of the guide plate on the flocculation effect are studied to optimize the flow pattern and improve the effluent quality.The simulation results show that the shape of the inflow tube affects the flocculation effect.All other conditions being equal,the square deflector is better than the round deflector in terms of hydraulic conditions.The use of corrugated plate deflector has better flocculation effect than flat plate deflector.The smaller the size of high-density clarifier,the greater the turbulent energy dissipation rate of corrugated deflector compared with flat deflector.The optimum size of the guide plate increases with the increase of the size.The hydraulic condition is better when the guide plate is installed higher than the guide tube.Increasing the number of guide plates can improve the flow turbulence intensity outside the guide tube.The simulation results can provide some reference basis for the engineering design of DENSADEG.