The effect of baffle spacing on hydrodynamics and solute transport in serpentine contact tanks

摘要

In their interesting article, the Authors evaluated the effect of baffle spacing on the hydrodynamics and transport performance in a scaled contact tank with variable baffle spacing. They applied large-Eddy simulation (LES) to solve the filtered Navier-Stokes equations. Then solute transport capacity was assessed by solving the 3D advection-diffusion equation for the conservative tracer injected. The results of the flow and concentration field were successfully compared with previous experimental data. The main transport phenomenon in serpentine-flow contact tanks was found to be advection. Wider compartments exhibited large recirculation zones in which the solute entered via action of turbulent eddies and stayed there longer than the mean resident time. The paper confirmed the importance of tank geometry (i.e. baffle spacing) in the design of effective serpentine disinfection tanks.