For 30 years Bar Screens FB Procédés have proved their worth, and continue to impress with their reliability and simplicity.
This simplicity of design makes them highly adaptable, enabling them to be installed either in a channel or in a substation, and to be integrated into existing structures without any modification to civil engineering.
Our gravity-feed operating principle is applied to all our products. Bar Screens whatever their width or depth.
French 100% design and manufacture of bar screens
From design to shipment automatic bar screensfrom the "Good For Execution" drawings sent to customers, to manufacturing drawings, laser cutting, assembly, stripping/passivation, wiring and testing, the entire manufacturing process is supervised by FB Procédés.
Choose a automatic bar screen FB Procédés means opting for a machine entirely designed and manufactured in France, meeting all European Conformity standards.
Gravity-operated bar screens
In a difficult environment such as wastewater treatment, machines are put to the test. Waste found in the networks (silt, wipes, sand, stones, etc.) can easily cause mechanical equipment to malfunction.
So, to ensure optimum performance of its Bar ScreensFB Procédés has invented and developed a unique process (no other bar screen on the market uses this system): gravity bar screens.
The question behind this process is simple: how can we avoid having mechanical elements moving in the water, in order to limit the risk of blockages, but also to guarantee long-term efficiency and reliability?
FB Procédés' answer to this question was to design a mechanism based exclusively on gravity, in stark contrast to the complex hydraulic systems, chain-driven systems and switch systems frequently encountered.
The Principle:
At the start of each cycle, the screen grapple descends open and lands at the foot of the screen. Due to the effect of its own weight and a question of angle, the mobile unit changes position, the strap relaxes, and releases a sensor which activates a limit switch. The direction of rotation of the motor is then reversed, the strap is tightened, the grapple closes and engages its teeth in the grid as it rises.
The benefits:
- No submerged mechanical parts = reliability and longevity
- Gravity mechanism = maximum simplicity, much more reliable than more complex systems
- Minimum number of parts = easy, low-cost maintenance
- Technical simplicity = affordable maintenance, whatever the operator's technical level.
A central strap for traction
All the Bar Screens FB Procédés uses a single, central strap to pull the screen grapple.
All our straps are made of polyester, a material that is extremely resistant to traction, tearing, ultraviolet rays, friction and humidity.
Why use straps rather than chains or cables?
Tensile strength: The breaking loads of our straps range from 3.5 tons to 12 tons. Visit screen grapple rarely exceeding 500 kilos, our straps' breaking loads are therefore at least 7 times greater than the actual load.
Moisture-resistant: Polyester straps are perfectly resistant to humidity, and can remain submerged without any risk of deterioration.
Low cost: Depending on the strap model, it costs between €10 and €15 (excl. VAT) per linear metre. We recommend changing the strap once a year, or more frequently if there are no signs of wear. Last but not least, it only takes fifteen minutes to replace the strap, without having to move the bar screen structure or stop the flow of effluent.
Easy, safe replacement: Strap replacement is carried out from the bar screen installation plan. This means there's no need to descend into the station or canal, and above all, no need to dry them out. The operation is therefore safe and can be carried out by station personnel, using minimal, standard tools.
Grid and air gap
For each bar screenThe grate is custom-designed to suit the hydraulic profile, air gap and maximum flow rate to be processed.
Air gap
It varies from 3 mm to 100 mm, depending on the application. At the design stage, the air gap is either determined by the specifications or, if not specified, by our engineering department, which will recommend the air gap best suited to the context.
Grid
Depending on the flow rate and hydraulic profile, the grate can be composed of bars welded only at their lower end. In this case, we call it a "free-bar" screen. Among other things, this prevents pebbles from "jamming" between two bars, and thus putting the flow of water at risk. bar screen in default.
For larger flows and higher water heads, the bars are held in place at both ends, using a double-grid system to avoid any risk of blockage.
The material
Bar screens FB Procédés are made entirely of stainless steel. Depending on specifications or requirements, options can be offered:
- Made entirely of 304L stainless steel
- Made entirely of 316L stainless steel
- Combined 304L stainless steel construction (above water: upper frame) and 316L stainless steel construction (below water: lower frame and screen grapple)
Servo-controlled bar screen
In Base, the automatic bar screens FB Procédés are equipped with a manual control box, mounted on one side of the upper frame. This is a box to which the limit switches and gearmotor are connected, with a "mushroom" type emergency stop and two push-buttons for "Up" and "Down" on the front panel.
As an option, we systematically submit a electrical control and servo box of our own design, equipped with a relay including our operating program, the fruit of our 30 years of experience.
We give our customers the choice of :
- Realize theautomatic bar screen by them, while complying with our basic wiring diagram supplied with the bar screen,
- Opt for a "turnkey" solution with the "standard FB Procédés" control and servo box supplied with the bar screen.
We strongly recommend the latter solution for three main reasons:
- Visit bar screen will be tested and adjusted with its own electrical box. Any problems are detected during the testing and inspection phase in our workshops,
- On site, all you need to do is power the electrical box and the bar screen is then autonomous,
- With hindsight, we're finding that we're encountering problems mainly on bar screens where we didn't supply the electrical box and our operating principles weren't respected.