Industrial fire brigades are showing increasing interest in turbine firefighting systems: turbines that generate a powerful watermist with very fine water droplets. The technology is already being used successfully by many industrial fire brigades for industrial incident scenarios, such as cooling of tanks and installations in large fire scenarios, dilution of gas emissions and firefighting.
Although to date the systems are almost exclusively used in the industrial environment, fire brigades in the public domain could also benefit from this type of extinguishing method for some scenarios.
The use of turbines for firefighting purposes is not new in itself. The technique was already used in Russia in the 1950s for firefighting in the oil and gas industry. A Hungarian company developed a turbine extinguishing system based on two MIG jet engines, which successfully extinguished a large number of burning oil wells in Kuwait in 1991. The oil wells had been set on fire by Iraqi troops during Operation Desert Storm, during which an international military coalition led by the US put an end to the Iraqi occupation of Kuwait.
Fighting the disastrous and massive oil fires was an enormous operational and logistical challenge. The use of turbine extinguishing proved to be particularly effective. The turbines were mounted on a tank, after which the vehicle was manoeuvred backwards towards the burning well. At a distance of approximately 15m, the turbines were turned on at full power, with two nozzles spraying water into the exhaust stream. The outflow of the turbine alone was powerful enough to literally ‘blow out’ the oil well. The addition of water, atomised by the vortex, served to prevent the well from reigniting in the overheated environment.
In the mid-1990s, turbine extinguishing was rediscovered by industry as a supplement to the capacity of company fire brigades in refineries and chemical plants. The German government and the chemical company BASF in Ludwigshafen jointly developed an extinguishing system based on two turbine engines provided by the government. A study at the ‘Institute der Feuerwehr Sachsen-Anhalt’ linked to the project concluded that the use of turbines to generate a bundled column of aerosols can be very effective as an extinguishing and cooling method in industrial fire scenarios. Subsequently, BASF had a second mobile response system built and other chemical companies also chose this solution.
Small drops, big effect
One of the companies supplying gas turbines for industrial firefighting systems is Liberty Gasturbine Holland. The company has been active in the firefighting market since 1989 and has since supplied dozens of systems to company fire brigades in Europe, the US, India, Australia and China. The company uses the name ‘Turbine Response System’ (TRS). The systems are assembled in cooperation with suppliers of fire engines on industrial fire trucks of any size. Director Michel Kooij explains the added value of turbines compared to traditional firefighting techniques based on fire monitors:
‘The main feature of a Turbine Response System is that it generates a jet of very fine watermist droplets, which are ejected with great force. These droplets have a size of 400 micrometres on average and have the character of aerosols, creating a very large cooling surface.’ Scientific research into the application of this technique has shown that the cooling effect of the watermist cloud generated in this way is six times greater than the effect of large water droplets created by using a ‘bound jet’. Due to the fine watermist, the water reaches its target much better at the specific locations to be cooled, such as storage tanks, pipe lines or process installations. Moreover, the extinguishing and cooling effect is achieved with significantly smaller quantities of water compared to the use of standard extinguishing monitors. A large amount of water is lost in a bound jet without contributing to the intended effect. Due to the relatively limited use of extinguishing water, the environmental impact of contaminated extinguishing water is also significantly reduced.
According to Michel Kooij, under favourable conditions, the generated jet of watermist has a range of up to 150m, depending on wind strength. A vertical height of about 80m can also be achieved. A great additional advantage of this fine watermist is that the principle of 3D extinguishing can be applied. Due to the vortex effect of the powerful air jet, the watermist also reaches places that are inaccessible to a fixed jet from an extinguishing monitor, such as the rear of installations and storage tanks. In addition to water mist, the TRS can also spray a water/foam premix. Thanks to the turbine, the throw length of the jet when using foam is significantly increased, allowing a foam layer to be built up from a greater distance. Industrial fire brigades that have a TRS actually use this foam option.
The 3D effect mentioned makes the TRS also suitable for use on railway yards (scenario wagon fire). As rail wagons are often close together and the extinguishing units cannot always get close to the seat of the fire, extinguishing or cooling must be carried out over a greater distance. In addition, a fixed jet from a standard fire monitor does not reach the rear of the wagons. With the 3D fire extinguishing effect of the turbine, the fine watermist reaches all sides of the wagons through the vortex. Fire scenarios at railway yards have been an argument for some chemical companies to purchase a TRS. A lot of chemical companies have their own yards on their premises.
Not a holy grail
Kooij emphasises that turbine extinguishing is not the ‘holy grail’ that covers all conceivable incident scenarios. For certain scenarios, such as large-scale tank and tank pit fires, the use of monitors to generate a foam blanket is the preferred method. The added value of turbine response systems is particularly evident in the application for cooling purposes and the dilution of gas clouds at spills. Especially gases that are highly soluble in water, such as ammonia, can be diluted well with a water aerosol jet. A telling example that Kooij cites is a recent gas incident at a chemical company in Germany. Deployment of a turbine response system led to a rapid knockdown of the escaping gas cloud, which meant the incident was quickly brought under control, personal injury and environmental effects were prevented and the company was able to quickly resume production. Two years earlier, the establishment had to deal with an almost identical incident. At that time, the company fire brigade did not yet have a turbine extinguishing system at its disposal, which meant that it took a considerable time before the incident was under control. The gas emission also resulted in several injuries on site. The company involved praised the proven added value of the turbine response system.
Kooij adds: ‘Each company must decide for itself, based on its risk profile and credible and normative scenarios, whether a turbine response system has added value for its company fire brigade, and in which types of incident it can be used. It is a question of weighing up the effect to be achieved against the investments that must be made to adequately cover the realistic incident scenarios. Based on the risk profile and the international Seveso safety regulations, the government imposes strict requirements on companies with a high risk for external safety. This category of companies may be required to cover the highest incident risks with their private company fire brigade or stationary extinguishing and cooling systems. This sometimes involves large investments, such as an own fire water network with pumps and hydrants of sufficient capacity. In practice, mobile extinguishing and cooling facilities prove to be of most benefit to companies and a turbine extinguishing system, which can achieve a large effect with smaller quantities of extinguishing agent, is a valuable addition to the company fire brigade arsenal.’
Several industrial fire brigades at major chemical companies use the added value of turbine extinguishing systems and use them successfully in their operational practice. Because chemical companies are generally not forthcoming with information about incidents, the results of using the systems to control and combat industrial incidents are underexposed. Nevertheless, there are now various examples of incidents that could be limited and quickly brought under control thanks to the deployment of a turbine response system. For example, a major fire in a storage tank at a terminal in Dormagen 12 years ago prevented escalation because surrounding tanks could be cooled very effectively. In 2017, the added value of applying the system at large indoor fires in complex industrial buildings was demonstrated. A fire in a 20,000m2 warehouse filled with bales of plastic was impossible to contain with a traditional fire service. Deployment of a turbine extinguishing system made all the difference. Intense black smoke in the hall was dispelled and the column of watermist that filled the hall did its job: the fire could be contained.
Although turbine response systems are not yet used by public fire brigades, they have already proven their worth outside of industrial areas. For example, the turbine response system of BASF of Antwerp was deployed in 2013 in a train disaster in Wetteren in the Belgian province of East Flanders. After the derailment of a goods train, three tank wagons containing a total of 300 tonnes of highly toxic and flammable acrylonitrile caught fire. Support by BASF’s company fire brigade with its turbine extinguishing system prevented escalation, as the fire spread and blew out the other tank wagons.
In addition to such transport incidents, the power of a turbine extinguishing system could also be used for other types of calamities in the public environment, such as firefighting in large and complex buildings. For example, warehouses of logistics companies reach immense volumes, which makes it impossible for the fire brigade to enter such mega warehouses for safety reasons in case of a developed indoor fire. Due to the long range of the finely atomised watermist cloud, a turbine response system could be effective in such complex fires. The same applies to fires in road tunnels and car parks, whether above or below ground. Some fire brigades are experimenting with extinguishing robots for these types of fires. Michel Kooij of Liberty Gasturbine Holland wonders whether these robots, which drag a filled hose line behind them, can reach the seat of a fire located on the third or fourth parking level deep inside the garage. The watermist jet from a fire turbine is able to penetrate deep into a garage or other complex building with difficult access. Public fire service organisations in urban areas where such fire risks are real may therefore consider adding a turbine response system to their equipment portfolio. The effectiveness of turbine response systems in reducing the risk of fire in urban areas can be evaluated by public fire brigades in urban areas. The effectiveness of turbine response systems, combined with the advantages of mobility and relatively low water consumption, make it worth exploring the possibilities.
Liberty Gasturbine Holland builds each turbine response system to customer specifications. The system construction is determined by the risk profile of the company and the types of scenarios that need to be controlled with the turbine. Most systems consist of one turbine, but on request two turbines can be placed on a chassis. The TRS can be mounted on vehicles of varying sizes. However, the weight of the vehicle must be taken into account. The most compact version of the TRS requires a load-bearing vehicle weighing at least 7.5 tonnes to hold the unit in place when the turbine is operating at full power. The largest TRS variant requires at least a 12-tonne truck chassis.
As traffic space between plants at refinery sites is often very limited, manoeuvring large vehicles at these locations can be difficult. Therefore, Liberty Gasturbine Holland has made its TRS units 360 degrees rotatable. This increases the possibilities for deployment at locations with limited manoeuvring possibilities. Because the turbine can be moved in all directions, even unfavourable locations can be reached without having to move the vehicle.
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Turbo Response System in operational practice: BASF Antwerp
For about 12 years a Turbo Response System or ‘turbojet’ has been part of the equipment of the fire brigade of the BASF chemical plant in Antwerp Harbour. It is ‘a magnificent machine and a very effective tool for various chemical incident scenarios that could occur on our site,’ according to Dieter Verschueren, expert emergency response at the BASF fire brigade. Operational records prove that bringing the turbojet to the front line did make a difference more than once, especially in scenarios with chemical emissions.
Dieter Verschueren adds: ‘One of the main reasons for BASF to develop and implement the firefighting turbojet, which is called “Turbolöscher” on the German BASF site in Ludwigshafen, is its capability to wash down or dissolve emissions of chemical gasses and vapours very effectively. The powerful watermist column spread by the TRS can reach distances as far as 120m. The very small aerosol-like watermist has big potential for washing chemical particles from the air in incidents with emissions. During one such accident chemical detection crews measured a significant drop in gas levels in the exposed area after the TRS was put in action. It resulted in a much smaller evacuation area and a quicker knock-down of the incident.’
Operational experience using the turbojet at large industrial fire scenarios is very limited at the Belgium BASF-site, Verschueren says, not because the TRS was not used on those occasions but simply because such fires are very rare on the Antwerp site. ‘We used the TRS on a big warehouse fire external from the site. Not a typical chemical incident scenario, but a complex fire to battle nevertheless, due to the volume of the building, the contents involved and the potential risk for fire crews. The most important effect of the TRS in this case was the rapid drop in temperature, due to the big heat absorbing capacity of the watermist. This tempered the fire considerably. In our opinion the TRS is also a very important tool for 3D cooling and “shielding” tanks and installations when a fire occurs at the terminal or in a process plant.’
Operational experiences also include some incidents in the public domain. Given the specialisation and experience of the BASF company fire brigade on chemical emergencies, the organisation is part of a public-private covenant with federal governmental agencies for the response on specific incidents and disasters. The largest incident involving the TRS of BASF in the operation was a large train accident in the town of Wetteren in May 2013. Several tanker cars containing the very toxic and inflammable acrylonitrile caught fire after the derailment. The incident posed a significant risk for a large area around the incident due to the emission of toxic gases and the risk for a BLEVE. The BASF turbojet was used for 3D cooling of exposed tanker cars and washing down the toxic gases/smoke. This effort proved to be very effective and escalation of the incident could be averted. The TRS was in action in Wetteren for several days.
Dieter Verschueren comments: ‘At the BASF site we have a lot of rail infrastructure as well, including some new rail tunnels that are inaccessible during incidents. The turbojet could be a very important tool on such occasions. We deployed some operational tests and exercises on rail infrastructure already. Also we tested the capabilities of our turbojet on the Antwerp industrial shunting yard in cooperation with the Antwerp fire brigade. Our TRS-system with crew and operational advisor are available for support in both the industrial and public domain nationwide. When we take the turbojet into the field outside the fences of BASF the Belgium Civil Defence will give support for the water supply. With the two turbojets on, our TRS requires 8,000 litres of water for full-capacity deployment. Those amounts are easily available in our BASF hydrant network, but not in urban or rural areas.’