The Hydro-Dyne perforated panels were drilled and custom engineered to allow for higher throughput capable of passing Romeoville’s peak wet weather flows and meeting their required head-loss and bypass water levels with no civil modifications.

Secondary access panels were also added at the lower deck for operators to evaluate the grid to ensure the wash water headers were offloading properly.

RESULTS:
Hydro-Dyne’s Great White has exceeded the city’s expectations:

• • The amount of compacted solids being removed is twice the amount of the previous system – one cubic yard dumpster every six days instead of every two weeks.
  • Solids that are removed are dryer and much more compact (Figure 3).
  • The new screen has greatly reduced the costs associated with rags collecting in downstream equipment; operators are no longer required to do the messy job of removing solids and rags by hand from their clarifiers, pumps, and slide gates, allowing them to focus on optimizing their plant.
  • Maintenance hours have been cut in half to only three hours per week.
  • Since screen installation, unplanned shutdowns of the four RAS pumps due to rags seizing the pump impeller have dropped from one unplanned event per month to zero unplanned events.
  • The plant is expecting to significantly reduce the costs associated with cleaning rags and debris out of the various process tanks; prior to screen replacement, they were spending about $125,000 every five years and now are planning to extend this maintenance cycle to ten years.
    
    

“The Center Flow screen overall is performing nicely – it is easy to work with and maintain,” said the plant engineer for the city of Romeoville. “Everyone is happy and agrees it was the best decision.”