Hydrok SnailScreen™

Wastewater Screening and Vortex Separation

Sewage Snails are becoming a major nuisance in the Wastewater Treatment process creating
serious operational problems downstream within aeration basins and secondary clarifiers. The
continued improvements to process treatment technologies are creating an ideal habitat for these
pests, whose shells can cause major maintenance problems as they breakdown to form an abrasive
grit leading to pump and equipment damage.

The Hydrok Snail Separator Screen utilises a specifically designed adaption of our wedge wire
technology in a 3mm version and utilised to create screening drums set within stainless steel
‘vortex’ chamber. The chambers are then used to separate the snails and their shells out of the flows
collected within a ‘snail screen sump’. The required design flow to treatment will be passed
through the ‘snail screen’ chambers without the requirement of power.

Operating Principles

Water and pollutants enter the system and are introduced tangentially inside the vortex separation
chamber forming a circular flow motion. Floatables and suspended solids are diverted to the slow
moving centre of the flow. Negatively buoyant solids settle out to an undisturbed sump chamber
below. The water flow passes concurrently through the separation screen mounted above the
vortex chamber. Floatables remain within the central “scum board” at the water surface and are
retained within the screen.