Hawk Measurement Systems was called in to control gravity thickeners to improve the underflow density pumped to digesters and filter presses at a wastewater treatment plant.
The customer had a major problem controlling their gravity thickeners at a wastewater treatment plant. Gravity thickeners at wastewater treatment plants do not use chemical floccing to settle suspended solids.
Suspended solids concentrations can change depending on peak and off flows in addition to how well the biological system is running in the other part of the plant.
Controlling the underflow density of the bed being pumped to digesters or filter presses is very important to reduce running costs for the filter presses and extremely important for the optimum performance of the digesters.
By installing low frequency, high powered sonar array transducers with auto cleaning, Hawk was able to penetrate through the high levels of suspended solids and still provide a reliable bed level for the underflow pump control of the gravity thickeners.