Prior to entering a flocculation tank, the water flows through a rapid mixing basin. Chemicals are injected just before the first mixing impeller and baffles throughout the basin to minimize short-circuiting. The treated water passes through a second mixing impeller before it exits the rapid mixing basin and enters the flocculation tank. FLUENT was used to accurately predict the appropriate placement of the impeller and baffles for proper mixing.

Velocity vectors show the flow through the mixing basin
Courtesy of Hazen and Sawyer