Belt screen GNAFO1

counter currentmechanical

Product name Dual-flow belt screen (GNAFO1)

Category / Typology WATER INTAKE / SCREENS

When to use it
The GNAFO1 dual-flow belt screen, equipped with metal-mesh filtering panels, is designed for screening intake water from sea, lake or river channels and other installations with high flow rates or significant depth. It is suitable where a large filtration surface and automatic cleaning are required for continuous water intake operations.

How it is made

• Robust frame manufactured from press-bent steel sheets
• Belt composed of modular metal-mesh filtering panels mounted on twin roller chains
• Two toothed wheels at the top to advance the filter panels along the roller chains
• Two toothed wheels at the bottom to guide and return the chains precisely
• Drive shaft supported on self-aligning bearings positioned between the upper roller chains
• Gearmotor for reliable drive
• Complete removal and washing system consisting of two counter-current washing ramps fitted with spray nozzles

How it works
Upstream water entering the unit divides into two flows that pass through the opposing filtering faces and rejoin inside the screen. Filtered water exits through a rear opening. The assembly is normally static; filter panels rotate only when the upstream/downstream level difference reaches a preset threshold. Debris larger than the mesh is collected on the panels, which lift the material out of the flow to the predetermined discharge height. At discharge height, material is removed from panels by a counter-current washing system that uses water already filtered by the screen. The wash water and screened debris are directed to a collection channel (typically reinforced concrete) and evacuated by flushing. The simple mechanical design and automatic cleaning ensure consistent performance and long-term reliability.

Strengths

• Suitable for deep intake channels and high flow rates
• Large effective filtration surface
• Robust construction with an expected service life exceeding 30 years
• Simple and cost-effective maintenance

Characteristics / Technical specifications

• Model: GNAFO1
• Type: Dual-flow belt screen with metal-mesh filtering panels
• Application: Sea, lake and river intake channels; other high-flow or deep-water intake situations
• Construction: Press-bent steel sheet frame
• Filter media: Metal-mesh panels assembled on twin roller chains
• Transmission: Upper and lower toothed wheels; drive shaft on self-aligning supports; gearmotor drive
• Cleaning system: Two counter-current washing ramps with spray nozzles using filtered water
• Operation: Normally static; automatic panel rotation triggered by upstream/downstream level difference
• Screened material handling: Integrated lifting action of panels to discharge at required height and washed off by counter-current water
• Discharge: Screened material and wash water flow to a collection channel for flushing removal (commonly reinforced concrete)
• Design benefits: Large filtration area, automatic cleaning, long service life, low maintenance