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Coanda-Effect Static Intake Screens

Coanda-effect static self-cleaning screens — an inclined wedge-wire surface with no moving parts that uses the Coanda effect to draw water through fine slots while shearing debris, sediment and fish over the top.

Coanda-Effect Static Intake Screens

Intake Screening for Water & Desalination Plants

A Coanda screen is an inclined, curved wedge-wire surface over which water flows; the tilted wires and the Coanda effect shear a thin layer of water through the fine slots (often under 1 mm) while debris, sediment and fish are carried across the surface and over the edge. With no moving parts and no power, it is self-cleaning and highly effective at fine-debris and sediment exclusion.

Background & History

Named after the Coandă effect (Henri Coandă), these static self-cleaning screens were commercialised from the 1980s–1990s for small-hydro and water-supply intakes. Their ability to exclude fine sediment, debris and fish with no power or moving parts made them a favourite for run-of-river and mountain intakes.

Types & Variants

Configurations in service

Ogee / Curved Profile

Accelerating curved surface maximises the Coanda shearing of clean water.

Tilted Wedge-Wire Deck

Wires tilted into the flow slice off a thin clean layer; sub-mm slots.

Small-Hydro Intake

Drop-structure intakes for run-of-river and mountain supplies.

Fish & Sediment Exclusion

Debris, sand and fish pass over the deck rather than through it.

Advantages & Limitations

An honest engineering assessment

Advantages

  • No moving parts and no power — passive and self-cleaning
  • Excellent fine-debris and sediment exclusion (sub-mm)
  • Strong fish/larvae exclusion
  • Very low maintenance and high reliability

Limitations

  • Needs a vertical drop/head (gravity-driven)
  • Limited capacity per unit width
  • Not suited to large, flat-site or deep open-water intakes
  • Performance varies with flow over the deck

Where It Fits

Typical applications

Coanda static screens suit run-of-river and small-hydro intakes, mountain and gravity water supplies, and fish- and sediment-sensitive abstractions where a passive, self-cleaning fine screen is wanted.

Other Intake Screen Types

The full intake-screen series

Related Equipment & Hubs

Specify the right intake screen

Our engineers select and size intake screening — coanda static and the full train — matched to your debris load, fish-protection duty and downstream process.

Industries We Serve

Our expertise spans multiple industries with sector-specific water treatment solutions.

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