The Coanda effect is a principle of fluid dynamics discovered in 1910. We used it to build the most reliable water intake technology on the market.
Stages 01 to 03. The water flows over the top edge of the weir, speeds up down the screen face and passes through the slots on the way. Any debris carried with the water keeps sliding down to the bottom edge.
Stage 04. At first the outlet valve is closed, so the screened water rises in the chamber and spills out under the screen. When the site technician opens the valve, the spill stops: every litre the screen takes in now leaves through the supply pipe.
HOW IT WORKS
Four-Stage Filtration
01
Acceleration PlateWater is guided onto a smooth acceleration plate at the top of the screen. The plate geometry is calculated to achieve a precise velocity distribution before contact with the screen surface.
02
Coanda Effect EngagementAs water flows over the curved screen surface, the Coanda effect, a fundamental principle of fluid dynamics, forces the water film to adhere to the screen and pass through the slots (the gaps between the V-shaped wedge wires).
03
Debris RejectionThe screen curvature and tilt angle ensure debris, leaves, sediment and aquatic life are carried over the screen surface by gravity and momentum. No mechanical cleaning needed.
04
Clean Water CollectionFiltered water is collected in the channel below the screen. From there it flows downhill under gravity, without pumping, to the intake pipe or storage tank, with no external power needed at any point in the process.
ON SITE
The same screen under the three conditions that determine whether an intake works: normal flow, autumn leaves and flood
The Coanda effect, seen close up. Water leaves the acceleration plate, clings to the curved wedge wire, and passes through slots roughly a millimetre wide.
Autumn leaf fall at a BUSKI (Bursa Water and Sewerage Administration) intake. The leaves ride across the screen face and off the bottom edge instead of blocking the screen. A bar screen cannot let leaves pass over it in this way.High-turbidity flood flow with sediment clumps. Conventional intakes clog in exactly these conditions, which is when power generation and water supply matter most.
ADVANTAGES
Why Coanda Outperforms Every Alternative
Compared to drum screens, trash racks, and mechanical filters, Coanda screens deliver superior performance with zero operational cost.
Self-CleaningThe screen surface geometry rejects all debris automatically. No rakes, no brushes, no compressed air. The screen cleans itself continuously during operation.
No Energy ConsumptionThe entire filtration process is powered by gravity. No pumps, no motors, no external power source. Operating cost is practically zero.
Minimal MaintenanceNo moving parts means no wear and no replacement parts. Maintenance is minimal: typically a manual cleaning at the change of seasons, depending on site conditions. Because nothing mechanical can fail, service life depends on the choice of material, which we match to the water chemistry.
Custom DesignedEvery screen is designed for the conditions of each site: flow rate, debris type, temperature, and installation constraints. No standard, ready-made products.
Environmental ComplianceEvery slot width protects fish and other aquatic life; the narrowest slot openings extend that protection to the smallest species. ADENCO screens can be supplied to meet the strictest environmental regulations for fish protection and water withdrawal.
All-Weather OperationThe stainless steel body and the V-shaped wire profile prevent ice formation and clogging in extreme cold climates.
TECHNICAL OVERVIEW
Key Operating Principles
OPERATING PRINCIPLECoanda hydrodynamic effect
ENERGY REQUIREMENTNone: gravity only
MOVING PARTSNone
WIRE PROFILEV-shaped wedge wire (stainless steel)
SLOT OPENING RANGE0.5 to 2.0 mm (1.0 mm standard); narrower slots on request
TILT ANGLE5° standard; 3° to 7° available
FILTRATION METHODSurface screening
SELF-CLEANINGContinuous, passive
Footage from installed intakes
The Coanda effect on video
Four short clips from installed intakes: debris carried off the screen face, protection bars (stainless steel bars mounted in front of the wedge wire that take the impact of rocks and timber) inspected after a flood, the seasonal manual cleaning, and what happens when flow exceeds the design flow.
Small debris carried off the screen faceFallen leaves and small debris carried onto a Coanda screen face are swept over the slots and off the apron plate below the screen, instead of clogging it.Protection bars after a floodAn irrigation intake near İnegöl, Bursa, inspected ten months after commissioning and just after a flood: the water pooled behind the weir is full of rock and sand, boulders lie on the weir crest, and the wedge wire under the protection bars (stainless steel bars mounted in front of the wedge wire that take the impact of rocks and timber) is intact and water continues to pass through it.Manual cleaning of a Coanda screenThe seasonal manual cleaning: brushing the wedge wire with a stiff plastic brush is the entire maintenance routine. No special tools, and no need to shut the intake down.Overflow across a Coanda screenFlow in excess of the design flow passes over the screen face and continues downstream, rather than accumulating behind the intake.
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