WATER MIST SYSTEM:
A SMART WAY TO FIGHT FIRE
MERCOR’s water mist system is a new category of state-of-the-art firefighting solutions from the MERCOR Group, based on fixed water mist devices – especially high-pressure water mist system kits and conventional sprinkler and water spray systems as well.
MERCOR, in cooperation with the renowned German manufacturer FOGTEC, brings proven water mist extinguishing solutions to the market.
High-pressure water mist extinguishing
system – design and operation
The FOGTEC high-pressure water mist system, distributed by the MERCOR GROUP, effectively eliminates fire hazards using micro-droplets of pure water (potable water or demineralized water).
Combining a special nozzle design with high pressure sprinkles water mist that ensures an effective surface more than 200 times greater than the output of a conventional sprinkler.
Water mist generated by a high-pressure fire extinguishing system is an airborne suspension of water droplets with 50–120 μm in diameter. With such a high dispersion of water, a number of features is bestowed upon the resulting medium, distinguishing it from the water sprinkled on a fire by traditional sprinkler nozzles and improving extinguishing efficiency.
Water mist effectively quenches fire, consuming 7 to 9 times less water than traditional sprinkler systems. This significantly minimizes the risk of water damage and thus the risk of property loss and production downtimes.
The mechanism behind high-pressure water mist extinguishing is based on three factors acting simultaneously:
- cooling – As it heats up during the fire and transitions liquid into gas, water absorbs heat from the combustion environment, while the total droplet surface is several hundred times larger than is the case for a standard extinguishing system. This ensures highly efficient use of the water sprinkled onto the fire, absorbing up to ten times more heat per mass unit than traditional water devices.
- local atmosphere inertization – water volume increases 1700-fold during the evaporation process. As a result of this process, oxygen is pushed aways from the fire.
- stopping heat radiation – a unique feature of high-pressure water mist consists in absorbing heat radiation by saturating the space with water mist, effectively preventing re-ignition and temperature increase. This property is particularly valuable in applications where it is important to protect components located near a fire source (e.g. support structure, process line, etc.) from excessive temperature rise
- Water mist propagation through air convection movements. Through their small mass, water mist droplets are suspended in the air, forming a colloidal system (aerosol), which, along with the convection movements of the air, reaches restricted spaces such as under the cover of a machine, etc.
Each project is developed according to strict FOGTEC guidelines derived from design manuals and full-scale fire tests performed. Only a combination of these two factors (guidelines + tests) guarantees an appropriate and effective system selection.
Based on the design manual, the designer selects the type of nozzle, nozzle parameters, nozzle placement and pump size, as well as the water supply tank.
FOGTEC systems are designed based on globally recognized standards: NFPA13 (hazard classes LH, OH1) and VdS3188 (hazard classes OH1 to OH3), as well as guidelines developed by the manufacturer based on full-scale fire tests (including for tunnels and cable rooms, battery rooms, flammable liquids and many others).
In many cases, the FOGTEC system can be used as a substitute solution, based on an adequate expert opinion, allowing to reduce or waive some of the requirements resulting from fire regulations, such as fire resistance class. This is due to its greater extinguishing efficiency compared to classic (large-droplet) extinguishing systems.
This kind of customized approach also ensures great flexibility of the system and efficient use of the materials needed for its construction.
EXAMPLE DIAGRAM OF A WATER MIST SYSTEM
A distinguishing feature of any water mist system are the modern, precisely designed nozzles, which are deployed not only under the ceiling, in false ceilings or sidewalls, but also in floors.
The water distribution pipeline is made of AISI 316L stainless steel (EN 1.4404) pipes with diameters between 10 and 60 mm. High hydraulic flexibility, which minimizes pressure loss even over very long sections, allows to build complex water mist systems using only one pump set, while high precision and cleanliness ensures long system durability
High-pressure water mist technology uses small pipe diameters (within the DN 12–60 range), which contributes to less stress on the building structure and facilitates installation in shafts and suspended ceilings. If additional sections are added to the facility, it is possible to expand the system quickly and cost-efficiently.
Classic spraying installation
Installation of low -pressure water fog
Installation of high -pressure water fog
Water mist - a system of advantages
As part of approval procedures, research projects or customized testing, all systems and components undergo fire testing. MERCOR systems are tested and approved by reputable certification bodies, such as VdS, FM and TüV, while production is carried out in accordance with ISO 9001-2000 certification.
The high-pressure water mist system from Mercor, which is based on FOGTEC solutions, holds a National Technical Assessment and a National Certificate of Constancy of Performance from the Polish authority CNBOP. The design of the system is based on laboratory tests conducted.
Applications
Through the application of advanced FOGTEC high-pressure water mist system, as well as extensive experience of FOGTEC Brandschutz GmbH, which is one of the world leaders in the field of fire protection, we are able to protect most areas / projects. Often using customized solutions, we are able to adapt the system to non-standard needs, replacing system templates with dedicated engineering solutions.
Water mist extinguishing is used in many industries and various types of facilities, in particular:
- industrial buildings, e.g. production lines (specifically dedicated in full or in sections), in paint shops or machine rooms (pumping stations, generator rooms, mazut plants)
- commercial power industry, in facilities such as conventional and gas-fired power plants, hydroelectric power plants and wind power plants
- server rooms,
- high-rise buildings,
- heritage buildings, such as museums, archives and historic sites. The water mist effectively extinguishes affected surfaces without causing damage to high-value property.
A high-pressure water mist system can also be used to protect electric cars indoors – such as in underground garages, as well as energy storage and battery rooms.
Get in touch
The active extinguishing department employs a team of expert engineers with international design experience, who have participated in dozens of projects involving high-pressure water mist system installations in Europe. It complements MERCOR S.A.’s existing solutions, thus creating a complete range of active and passive fire protection.
Practitioners with many years of experience in the industry are at your disposal, ready to discuss all the relevant topics.
