Many types of clarifiers are found in water and wastewater treatment plants and their primary function is to provide a plug flow that encourages the settlement of particulate matter.
Sometimes the design of inlet channels that carry flow to clarifiers produce imbalances (right). In these situtations, CFD can be used to identify reasons for the flow imbalance and to develop cost effective corrective actions.
CFD can also be used to model fluid flow and the simultaneous settlement of solids. This allows us to assess the performance of secondary clarifiers. The results below show the position of a sludge blanket that has migrated across the hopper that is used to withdraw return activated sludge (RAS). The “launders” through which the clarified water flows are shown at the bottom right of the graphic.
CFD simulations allow us to identify important flow features and to determine the ability of design changes to improve the performance of clarifiers before fieldwork is begun.