Sed Tank Temperature Gradients

Sed Tank Temperature Gradients

The Sed Tank Temperature Gradients team aims to find solutions to improve sedimentation tank performance during periods when the water entering the sedimentation tank is warmer than the water in the sedimentation tank.

Current & Future Research

This research was prompted by the rising flocs observed at the San Nicolas AguaClara plant.

Temperature gradients cause deterioration of performance in tube settlers even when the total flow through the tube settler is controlled. A 0.75 C/hr temperature gradient showed a very different flow pattern than the 0 C/hr control.

Preliminary analysis of the effects of floc density difference due to the floc consisting of warm water and then settling into cold water suggests that this density difference is not sufficient to cause a failure in sedimentation. The lift on a sphere in a velocity gradient is also insufficient to prevent flocs from settling in a tube settler.