Tracer studies of inlet baffle performance in a horizontal rectangular settling tank model

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Virginia Polytechnic Institute


Inlet baffles in a sedimentation basin should distribute the incoming flow uniformly over the inlet zone. This allows the flow to pass through the tank in a plug flow fashion, giving the solids a more quiescent condition to separate from the liquid. It was the object of the investigation to determine which of the baffles studied performed this function most efficiently.

Conventional, statistical, and dynamic analysis techniques were employed to evaluate baffle performance from input-output relationships of salt concentration. The statistical approach appeared to give much more meaningful information than did the "qualitative" or "conventional" parameters. The pulse testing techniques appeared to give more detailed information regarding the hydraulic characteristics of the model system tested.

The model study results indicated that a 6-inch horizontal rectangular inlet baffle, positioned 8 inches from the inlet pipe, gave better performances than the other baffles tested.