Application of Computational Fluid Dynamics for Optimal Design of Horizontal-Flow Baffled-Channel Powdered Activated Carbon Contactors

Abstract

For more efficient design of a horizontal-flow baffled-channel powdered activated carbon (PAC) contactor (hBPC), which might be used to cope with taste and odor problems at conventional water treatment plants, computational fluid dynamics (CFD) using FLOW-3D was applied. In order to verify the performance of the CFD simulations, the experimental results of tracer tests from a pilot-scale hBPC were compared to those from the simulation. Results from the CFD simulation were very similar to those of the tracer tests. Velocity distributions showed that there were stagnant regions on the back side of the baffles. These stagnant regions would be expected to decrease the overall adsorption efficiency of the PAC particles. The size of the stagnant regions and retention times in the simulated hBPC increased as the length to width (L/W) ratio increased and the bend width decreased. The L/W ratio, bend width, and the number of baffles for optimal design of the hBPC were successfully generated by the simulation. When designing a full-scale hBPC, the designer should consider the L/W ratio, number of baffles, and bend width in order to maximize the hBPC performance.