Numerical Simulation on the Hydrodynamics of Sedimentation Tank When Longitudinal Inclined Plates Are Employed

The effect of the addition of longitudinal inclined plates on the settling efficiency and the overall hydrodynamics of a rectangular sedimentation tank is investigated using computational fluid dynamics. A full-scale three-dimensional model is used for the simulation. Experimentally obtained particle size distribution data of a potable water treatment plant and an industrial wastewater treatment plant is used. After the addition of the longitudinal inclined plates, the settling efficiency reaches 67.54% for the industrial wastewater particle size distribution and 94.75% for the potable water treatment particle size distribution, which were 42.67% and 79.15% respectively, before the modification. This significant improvement in settling efficiencies can be attributed to the increase in the settleable area and also to the reduction in dead zones. A stark difference is also observed between the modified and the original sedimentation tank in the velocity contour, and turbulence kinetic energy contour.