Fixed firefighting systems for road tunnels Johnny Jessen, Business Development Manager - Underground Facilities, VID Fire-Kill reports that the company has experienced an increase in interest for the TUNPROTEC® Low Pressure Watermist Solution for tunnel protection. The reason for this is believed to be a combination of different factors such as a growing focus on safety and property damage in road tunnels and the large amount of research conducted showing the effectiveness and benefits of fixed firefighting systems in tunnels.
TUNPROTEC® Fixed Fire Fighting System for tunnel protection has been developed by VID Fire-Kill, a Danish-based leading developer and supplier of low pressure water mist firefighting systems and components. Within the last couple of years, we have noticed a growing interest for our specially designed tunnel solution. This interest, we believe, is due to a combination of things. Full-scale tunnel fire tests have proven that fixed firefighting systems can even suppress large heavy goods vehicle fires, while tunnel owners are required to provide better protection of their tunnels to protect people as well as property assets and decrease the downtime or closure of a tunnel after a vehicle fire. The most common fixed firefighting systems for tunnels are either deluge or water mist (low or high pressure). Both technologies work in deluge operation, dividing
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the tunnel into 20 - 30 m fire zones with open nozzles that are activated by opening a section valve. Both technologies use many of the same firefighting methods, but with variations. Deluge/sprinkler firefighting Deluge systems operate with distribution of large droplet sizes (> 1mm) with low kinetic energy when discharged by the nozzle. Deluge systems suppress the fire by discharging large amounts of water over specified areas and thereby wetting and cooling the fuel surface. Deluge/sprinkler systems typically use open sprinkler heads/nozzles, applying typically: Nozzles: Min. 1.1 bar Pumps: 6 bar Deluge/Sprinkler offers: Robustness, High water consumption/flow rate, Less maintenance than high pressure water mist,
Lower component costs (using typically coated steel pipes (PN16)), Can share water-main with the hydrants Water mist firefighting Water mist employs several firefighting methods that make it equal or better than deluge/ sprinkler solutions, but with significantly less water consumption. Water mist uses a combination of wetting the surface and distributing smaller droplets which quickly can absorb more energy/heat from the fire than the larger droplets distributed by deluge systems. Water mist (High Pressure) Operates with a relatively high pressure and uses open sprinkler heads/nozzles, applying typically: Nozzles: 35-80 bar Pumps: 64-140 bar High pressure water mist technology distributes water in very
