Name: Coanda Screen
Brand: JX Filtration

Description

JX Filtration offers a full range of Coanda Screens from compact intake boxes to large hydropower diversion assemblies, with flexible customization options to suit various flow rates and screening needs across water treatment, hydropower, irrigation, and aquaculture—passive, self-cleaning, and built for decades of submerged operation.

A Coanda Screen, also known as a Coanda Effect Screen or Coanda Intake Screen, is a static solid-liquid separation device installed on the downstream face of an inlet weir. It uses the Coanda effect—the tendency of a fluid jet to remain attached to a curved surface—to maintain constant contact between the flow and a curved wedge wire screening surface. With no moving parts and no power requirement, the screen achieves continuous self-cleaning fine-debris exclusion, making it an economical and environmentally sound solution for surface water intakes. The critical structure is the wedge wire and support rod formed wedge wire plate, reinforced by JX Filtration's high-strength frame and stiffeners.

Working Principle

Flow Acceleration: Water is conveyed through an ogee-shaped accelerator plate at a defined angle and speed required for the screen separation zone. The accelerator plate smooths the water and delivers it to the screen at the proper angle and direction.
Coanda Effect Screening: The flow remains attached to the curved wedge wire surface due to the Coanda effect, ensuring constant screen surface contact. The wedge-shaped profile wires are tilted so their leading edges project into the flow, shearing a thin layer of water through the fine slots while debris is retained on the surface. Because the wire tilt shears rather than sieves, the effective exclusion size is roughly half the slot opening—fine enough to reject sand, fine debris, and fish larvae.
Self-Cleaning & Collection: Debris and sediment ride along the smooth outer surface of the screen and are carried away by the flow, eliminating the need for backflushing. The screened water passing through the open area accumulates in the chamber below before being conveyed to the intake pipe.

Advantages

No moving parts – Passive operation with no power source, motor or mechanical components; largely self-cleaning with minimal maintenance
Fine debris & sediment exclusion – Filtration precision of 0.2–5 mm, with debris and sediment interception rate up to 90% or higher
Fish & aquatic life protection – Low approach velocity and wedge wire shear action prevent impingement of fish, larvae and other organisms
Clog-resistant wedge wire – V-shaped profile wires with narrow top and wide bottom gaps ensure smooth drainage and prevent particle wedging
Low water loss – Less than 5% water loss during operation
Corrosion-resistant materials – Stainless steel 304/316/316L and special alloys with electrolytic polishing for extended service life
Long service life – Up to 20 years in typical intake applications
Compact and economical – No mechanical equipment required, reducing installation and operating costs
Customizable design – Slot sizes, screen angles, dimensions, and materials tailored to specific intake requirements