Tarnos S.A. is a leading manufacturer of water intake screening systems, we have a honed capability to comply with the technical and quality requirements of the most demanding projects in all fields, as our experience covers capital projects such as Desalination, Power Plants (including Nuclear) & Petrochemical projects.
Traveling water screen assemblies and related equipment (water intake screening equipment) are used to filter debris and aquatic life in varying sizes, from raw water sources such as rivers, lakes, streams and oceans. Screening systems are utilized at fossil-fuel power plants, nuclear power plants, drinking water facilities, desalination plants, refineries and other heavy industrial sites where large volumes of raw water are consumed.
Our screens are “Link-Belt”, manufactured under a technical agreement with FMC (USA), dated 1976. There are more than 6.000 Link-Belt Traveling Screens installed around the world, in more than 2.000 facilities of all types.
Our designs are proven and have been optimized through many iterations, resulting in cost-effective and efficient solutions for all water intake screening requirements. Our screens have low operational costs and require minimal maintenance.
Channel Isolation Gates & Stop-Logs
Tarnos manufactures channel isolation equipment such as stop-logs. These gates are employed mainly for maintenance and are a usual complement of water intake screening solutions. Stop-log gates are usually acted by means of a gantry crane.
Our gates have high water tightness, and reach Class 1 & Class 2 in DIN19569-4 specification. We have no size limitation when designing these units.
Coarse Screens: Bar Screens & Trash Rakes
Usually the first screening stage in many intakes, a bar screen is designed to retain solids of medium to large size such as algae, jellyfish, plastic bags, weeds and other material sizing 20-200 mm.
Due to their size and capacity, these screens require automatic cleaning. For this purpose we manufacture automatic trash rakes (fixed or trasversomg) that maintain these bar screens in clean and working condition.
Fine Screens: Traveling Band Screens
Once the coarse debris has been removed by a bar screen, a finer screen is usually required to further reduce the size of solids carried by the water, depending on downstream process or pumping requirements.
For this stage of fine filtration, we manufacture proven designs of traveling band screens, which have a great efficiency in the automatic screen removal of large quantities of debris sized 0,5 to 20mm, such as weeds, algae, plastics and other floating matter.
A traveling band screens consists of a continuous band of overlapping screening trays, designed to offer the minimum practical obstruction to the free passage of water. There are four types of Traveling Band Screens that we manufacture:
- Through flow screen, which cover the whole width of the channel, they require minimum implication in civil works.
- Dual flow screen, or outside-to inside screen, that employ both sides of the band. This type of screen does not have carryover and is more efficient in screen size vs a through flow for the same process parameters, but requires additional civil works.
- Centre flow screen, or inside to outside screen, of similar conceptual design to a dual flow.
- Retrofit screen, or a dual flow screen installed in an intake that once employed a through flow with little to now civil modification
Special Project Requirements
We are experts in the design of equipment for marine conditions, having participated in major desalination projects in the middle east, as well as power generation projects all around the world. As such, we have direct knowledge of the effect of corrosive ambient in the durability of our screening equipment, moreso considering that our machines are designed with a design life of 30+ year for critical processes.
We can manufacture our equipment in duplex and superduplex alloys, with a PREN > 40.
Marine & River Life
Certain sea water intakes have a prevalence of algae & jellyfish blooms, that can even block a standard water intake. We can design specially tailor made systems designed to operate in these conditions.
However, if the particular characteristics of the intake require the protection of the fish that is abstracted from the body of water, we have bar screen & traveling water screen designs that can work to safely extract this fauna from the filtered water and return them to their original body of water.