Seydioğlu HPP (hydropower plant) intake after the Coanda retrofit, water flowing in a clean, thin sheet over the screen face

PROJECTS

Retrofitting Guide

Replace your mechanical screening system with a self-cleaning Coanda screen that needs no external power, and know exactly what concrete work it takes, if any, before you commit.

THE SAME INTAKE

Seydioğlu HPP (hydropower plant), before and after. Drag to compare.

The original Tyrolean bar screen at Seydioğlu HPP, clogged with leaves, branches and plastic waste — Before: the original Tyrolean bar screen, clogged with leaves, branches and plastic waste, which is what forced the flood-season shutdowns. After: the same intake after the retrofit, diverting 2,500 l/s with debris carried across the screen face instead of held against it.

The same comparison at 10–30 l/s: village intakes from the TISKI (Trabzon Water and Sewerage Administration) project.

Tonya, Karaağaçlı intake before the retrofit: a rusted steel bar screen over a chamber of dark, silted water — Tonya, Karaağaçlı, 30 l/s. The simplest direct replacement among these sites: the rusted bar screen was removed, the existing concrete walls stayed, and the Coanda screen was mounted on the weir between them.

The same site after the retrofit, a Coanda screen mounted on the weir between the existing concrete walls — Tonya, Karaağaçlı, 30 l/s. The simplest direct replacement among these sites: the rusted bar screen was removed, the existing concrete walls stayed, and the Coanda screen was mounted on the weir between them.

Çaykara, Uzungöl intake before the retrofit: a loose rock channel with a black supply pipe laid on the bed of the creek — Çaykara, Uzungöl, 30 l/s. Before: the supply pipe simply lay in an open rock channel. After: a small concrete weir with the Coanda screen on its downstream side and the creek flowing over it.

The same creek after the retrofit, water flowing in a thin sheet over an ADENCO Coanda screen built into a new concrete weir — Çaykara, Uzungöl, 30 l/s. Before: the supply pipe simply lay in an open rock channel. After: a small concrete weir with the Coanda screen on its downstream side and the creek flowing over it.

Beşikdüzü, Çakıllı, before the intake was built: a shaded forest stream flowing over bare rock, with no intake structure — Before: the forest stream at Beşikdüzü, Çakıllı, before any structure was built. After: the same spot with a compact concrete intake and a Coanda screen with a rated capacity of 10 l/s. These are three of the 64 TISKI sites; the retrofit logic is identical to the hydropower case above, only the size of the structure changes.

The same forest stream after the intake was built: a compact concrete structure with an ADENCO Coanda screen and the supply pipe leaving it — Before: the forest stream at Beşikdüzü, Çakıllı, before any structure was built. After: the same spot with a compact concrete intake and a Coanda screen with a rated capacity of 10 l/s. These are three of the 64 TISKI sites; the retrofit logic is identical to the hydropower case above, only the size of the structure changes.

WHY RETROFIT

Advantages of Retrofitting

Uninterrupted Water Supply

A bar screen or trash rack clogs with leaves and branches, and on a mountain stream that means cleaning it by hand several times a day, or the intake stopping completely in the flood season. A Coanda screen uses the flow of the river itself to sweep debris across the screen face and carry it downstream, so screened water keeps flowing with nobody on site.

Supply Through Winter

In freezing weather, small ice crystals freeze onto submerged trash rack bars and choke the intake at exactly the moment the site is hardest to reach. Water moving across a Coanda screen face keeps it open under snow and ice: ADENCO mountain intakes in Türkiye keep operating beneath ice cover through the winter. When the intake supplies a drinking water network or a hydropower plant that must generate through the winter, this is usually the deciding reason for the retrofit.

No Electricity, No Moving Parts

Remove the motors, drive units, and control panels. The screen is driven by the water flow alone and needs no power supply, so there is no electrical connection at the intake, no electrical equipment to fail in a storm, and nothing that can break down as the water rises.

Maintenance Is Reduced to Inspection

No spare parts, no service contracts, no annual overhauls. Maintenance is reduced to a seasonal clean by hand and an annual inspection; a retrofitted intake typically goes from daily cleaning to a few site visits per year.

Finer, More Consistent Screening

The standard 1 mm slot gives far finer screening than the trash rack it replaces, and capacity stays the same regardless of debris load or weather. Turbines and downstream treatment plants receive cleaner water from day one.

Regulatory Compliance Built In

Fish and debris are carried across the screen face and returned to the river, and the screen can be supplied to meet fish screening regulations that mechanical systems may not satisfy. We supply the documentation for your permit application.

THE PROCESS

From Assessment to Operation

Site Assessment

We evaluate your existing intake structure: channel dimensions, weir geometry, flow conditions, and debris type and load. This can be done remotely with photos, drawings, and basic measurements.

Hydraulic Design

2 business days

Our engineering team designs a Coanda screen configuration that fits your existing concrete structure. We optimise screen geometry, tilt angle, and slot width (the gap between the wires) for your specific flow and debris conditions.

Manufacturing

2–4 weeks

Every screen is custom-manufactured in our facility from certified stainless steel. We provide full material traceability (EN 10204 Type 3.1) and dimensional inspection reports.

Delivery & Installation Support

1–2 weeks

Screens are delivered worldwide with detailed installation drawings. We provide remote installation guidance or on-site supervision as needed. The scope of concrete works is determined at the design stage: replacing an existing Coanda screen with a new one needs no structural work; converting a conventional intake may need small changes to the concrete or, on large hydropower structures, a supporting steel frame.

Commissioning

Same day

Once installed, the screen starts working immediately and commissioning is simple. No electrical connections, no calibration, no control systems. As soon as water flows, screening begins.

Retrofit FAQ

Do I need to modify my existing concrete structure?

It depends on what you are replacing. If existing Coanda screens are being swapped for new ones, no concrete changes are needed: the new screens are built to the same interface and fit into place. Converting a conventional intake usually means local concrete revisions to support the acceleration plate and to form the collection channel; where that concrete work would be substantial, as on large hydropower structures, the alternative is to mount the screens on a fabricated steel support frame instead. For small flows, the pre-assembled ADENCO-BOX puts screen, housing and outlet in one prefabricated unit, so a site can be served with almost no concrete work at all. The site assessment tells you which case applies to your site before you commit to anything.

Can I retrofit while the hydropower plant is operating?

Yes, and it has been done at many operating hydropower plants and water supply intakes. On intakes with multiple screens the work is done in stages: flow is shut off over one section at a time, the screens are installed there, water is returned over the finished section, and installation moves on to the next. The intake keeps taking water through the sections not being worked on. For intakes with a single screen, the work is done during a planned shutdown instead; mounting a screen is fast, typically 1 to 2 hours per unit.

Will the screen keep working under snow and ice?

Yes. Conventional trash racks fail in winter because small ice crystals freeze onto the submerged bars and choke the intake. On a Coanda screen the water moves across the screen face rather than through a submerged panel, which keeps the screen face open: ADENCO mountain intakes in Türkiye keep taking water beneath ice cover through the winter, and the screen face becomes free of ice again on its own once the flow and the temperature return to normal.

See the case study: two Trabzon intakes photographed under ice

What happens during floods and the heavy debris season?

Flood season is when the self-cleaning matters most. Flood flow arrives with the heaviest debris load, but it also brings the excess flow that sweeps leaves, branches and litter across the screen face and carries them downstream. The screen keeps diverting its design flow at exactly the moment a conventional screen used to clog.

What happens to my existing mechanical system?

Your existing mechanical system can be fully removed. Once the Coanda screen is installed, there are no motors, drive units, controllers, or moving parts to maintain. Your electrical and mechanical infrastructure for screening is no longer needed.

What information do you need to start?

We need the channel and weir dimensions, the design flow rate, the debris type, the characteristics of the river or canal, and photos of the existing intake. Our team will help you at each step.

How long does the full retrofit process take?

Design drawings are ready in 2 business days and manufacturing takes 2 to 4 weeks for standard orders, up to 6 weeks for multi-unit arrays and up to 8 weeks for arrays of more than ten units. The overall time to an installed screen then depends on screen size, shipping, and site scheduling.

Ready to Retrofit?

Send us your site details and our engineering team will assess your retrofit potential. No obligation.