How it Works
Water flows into the chamber (red arrow) and begins to
flow through the Heliscreen’s semi-cylindrical stainless steel perforated screen.

Water levels in the chamber rise, initiating the rotation of a
helical brush mechanism on the influent side of the screen.
The spinning helical brush scrubs solids away from the screen and into the continuation flow while the effluent is discharged to a spillway (blue arrow). The screenings and continuation flow are carried on for further treatment (brown arrow).

As the water level continues to rise, spill flow and continuation flow pipes become surcharged. Excess flows are bypassed over the back plate/emergency overflow weir. Unlike most CSO screens the powered motor of the Heliscreen sits above the back plate to ensure that the device will continue to operate even in the event of surcharges.