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Aerosol extinguishing technology has become a viable alternative to gaseous systems in a range of applications, says GianGuido Gianfilippi de Parenti. Here he explains how the technology works and the main considerations for its installation and use.
The restrictions in the 1990s in the supply of Halon as a gaseous extinguishing agent, due to its ozone depleting characteristics, gave an added impetus to develop viable aerosol extinguishing systems. The technology has its origins in the Soyuz space programme and originally consisted of a solid aerosol forming compound made of Potassium salts and nitrocellulose, a boosting material used as an accelerator from the solid phase to aerosol phase. Nitrocellulose, however, is a pyrotechnical material and therefore can be unstable in increased temperatures and over time, its mechanical properties decay resulting in loss of efficiency.
This led to manufacturers developing new aerosol forming compounds free of pyrotechnical materials, so providing stability in temperature rises and a lifespan of 15 years compared to five. As a result, today this technology is seen as one of the most efficient ‘Halon alternatives’ available.
Aerosol extinguishing systems employ a solid compound which is transformed into an aerosol that extinguishes fire by breaking the uncontrolled chemical chain reactions of combustion – without depleting oxygen. Their success can be partly attributed to their versatility which also allows for internal/local protection of areas where a fire might start e.g. electrical panels, cabinets etc. Some of the main benefits of the technology are:
– space saving – the space required is only a fraction of that needed for cylinder based systems
– uncomplicated parameters resulting in simplified design calculations
– no piping, pressure cylinders, special supports or valves are required so reducing installation time and costs
– easy maintenance without the need for pressure testing, weighing, pressure/leak detection etc.
– aerosol extinguishing systems are less expensive compared to most other gaseous systems (Halon replacements)
Various national and international standards for condensed aerosol extinguishing systems have been developed (see panel). Products and systems are tested for their extinguishing performance for different classes of fire, and for the mechanical functions of various components. Accreditation bodies can issue type approvals, performance reports and product certifications or listings when tested against the recognised standards.
Consultants and specifiers in the UK should require that the manufacturer is certified to ISO 9001 and ISO 14001, the products are certified/listed by a UK accredited authority such as BSI or LPCB for land applications and by MCA for marine applications, and that the products carry the green label, thus ensuring that they are environment friendly. Additional certifications and listings issued by other accredited authorities will be an added advantage. Each extinguishing system model and size has to undergo all the tests mentioned in the standards in order to be certified, and all the models tested have to be listed in the certification issued. End users, specifiers and any inspection or enforcement authorities should expect to receive all information relevant to the certification including all the relevant technical information, data sheets, design calculations and operating manuals. Specifically, the certificate issued by an accredited body should mention:
– the extinguishing application density (in grams per cubic metre) for each class of fire ( A (E),B,C,F), derived by the extinguishing tests (as per test protocols of the relevant standards)
– the derived design application density (a 30% safety factor has to be added to the extinguishing application density)
– the mechanical test of the generators’ components; part of these tests is the ‘accelerated ageing test’, which indicates the certified lifetime of the product
Green credentials
Some of the newly developed fire extinguishing aerosol generators do not contain any substances which are harmful to the environment and which are in the process of being banned or restricted under (EC) No 842/2006. On the contrary, the certifications and reports owned by some aerosol manufacturers are demonstrating that the characteristics of the product/technology are consistent with the most stringent international environmental requirements. One of these is the EU Green Label Mark which is intended to promote the design, production, marketing and use of products, which have a reduced environmental impact during their entire lifecycle.
GianGuido Gianfilippi de Parenti is director of the technical division of FirePro Systems Ltd www.firepro.info
NATIONAL and INTERNATIONAL STANDARDS
The following is a list of national and international bodies which have issued standards on condensed aerosol extinguishing systems:
– KIWA (Netherlands, EU)
Brl-k23001/03 May 24 2006 edition Evaluation guideline
Brl-k23002/02 October 20 2003 edition Evaluation guideline
Brl-k23003/03 May 24 2006 edition Evaluation guideline
CE Mark KIWA grants the listed aerosols under the BRIS to mark the products with the CE mark
– International Maritime Organisation (IMO) Msc/Circ.1270 4 June 2008
– Australian/New Zealand standard (Standards Australia)
– European Committee for Standardisation (CEN) PREN/TR 15276-1&2
– United States Environmental Protection Agency: Significant New Alternatives Policy (SNAP) program ‘Substitutes for Halon 1301 as a total flooding agent’ available at http://www.epa.gov/ozone/snap/fire/lists/flood.html
– National Fire Protection Association (NFPA)
– Underwriters Laboratories Inc (UL)
– International Standard Organisation (ISO)
– Australian Transport Council: The National Marine Safety Committee
– BSI – Kitemark License: Aerosol Fire Extinguishing Systems
Aerosol extinguishing technology has become a viable alternative to gaseous systems in a range of applications, says GianGuido Gianfilippi de Parenti. Here he explains how the technology works and the main considerations for its installation and use.
The restrictions in the 1990s in the supply of Halon as a gaseous extinguishing agent, due to its ozone depleting characteristics, gave an added impetus to develop viable aerosol extinguishing systems. The technology has its origins in the Soyuz space programme and originally consisted of a solid aerosol forming compound made of Potassium salts and nitrocellulose, a boosting material used as an accelerator from the solid phase to aerosol phase. Nitrocellulose, however, is a pyrotechnical material and therefore can be unstable in increased temperatures and over time, its mechanical properties decay resulting in loss of efficiency.
This led to manufacturers developing new aerosol forming compounds free of pyrotechnical materials, so providing stability in temperature rises and a lifespan of 15 years compared to five. As a result, today this technology is seen as one of the most efficient ‘Halon alternatives’ available.
Aerosol extinguishing systems employ a solid compound which is transformed into an aerosol that extinguishes fire by breaking the uncontrolled chemical chain reactions of combustion – without depleting oxygen. Their success can be partly attributed to their versatility which also allows for internal/local protection of areas where a fire might start e.g. electrical panels, cabinets etc. Some of the main benefits of the technology are:
- space saving – the space required is only a fraction of that needed for cylinder based systems
- uncomplicated parameters resulting in simplified design calculations
- no piping, pressure cylinders, special supports or valves are required so reducing installation time and costs
- easy maintenance without the need for pressure testing, weighing, pressure/leak detection etc.
- aerosol extinguishing systems are less expensive compared to most other gaseous systems (Halon replacements)
Various national and international standards for condensed aerosol extinguishing systems have been developed (see below). Products and systems are tested for their extinguishing performance for different classes of fire, and for the mechanical functions of various components. Accreditation bodies can issue type approvals, performance reports and product certifications or listings when tested against the recognised standards.
Consultants and specifiers in the UK should require that the manufacturer is certified to ISO 9001 and ISO 14001, the products are certified/listed by a UK accredited authority such as BSI or LPCB for land applications and by MCA for marine applications, and that the products carry the green label, thus ensuring that they are environment friendly.
Additional certifications and listings issued by other accredited authorities will be an added advantage. Each extinguishing system model and size has to undergo all the tests mentioned in the standards in order to be certified, and all the models tested have to be listed in the certification issued. End users, specifiers and any inspection or enforcement authorities should expect to receive all information relevant to the certification including all the relevant technical information, data sheets, design calculations and operating manuals. Specifically, the certificate issued by an accredited body should mention:
- the extinguishing application density (in grams per cubic metre) for each class of fire ( A (E),B,C,F), derived by the extinguishing tests (as per test protocols of the relevant standards)
- the derived design application density (a 30% safety factor has to be added to the extinguishing application density)
- the mechanical test of the generators’ components; part of these tests is the ‘accelerated ageing test’, which indicates the certified lifetime of the product
Green credentials
Some of the newly developed fire extinguishing aerosol generators do not contain any substances which are harmful to the environment and which are in the process of being banned or restricted under (EC) No 842/2006. On the contrary, the certifications and reports owned by some aerosol manufacturers are demonstrating that the characteristics of the product/technology are consistent with the most stringent international environmental requirements. One of these is the EU Green Label Mark which is intended to promote the design, production, marketing and use of products, which have a reduced environmental impact during their entire lifecycle.
GianGuido Gianfilippi de Parenti is director of the technical division of FirePro Systems Ltd www.firepro.info
NATIONAL and INTERNATIONAL STANDARDS
The following is a list of national and international bodies which have issued standards on condensed aerosol extinguishing systems:
– KIWA (Netherlands, EU)
Brl-k23001/03 May 24 2006 edition Evaluation guideline
Brl-k23002/02 October 20 2003 edition Evaluation guideline
Brl-k23003/03 May 24 2006 edition Evaluation guideline
CE Mark KIWA grants the listed aerosols under the BRIS to mark the products with the CE mark
– International Maritime Organisation (IMO) Msc/Circ.1270 4 June 2008
– Australian/New Zealand standard (Standards Australia)
– European Committee for Standardisation (CEN) PREN/TR 15276-1&2
– United States Environmental Protection Agency: Significant New Alternatives Policy (SNAP) program ‘Substitutes for Halon 1301 as a total flooding agent’ available at http://www.epa.gov/ozone/snap/fire/lists/flood.html
– National Fire Protection Association (NFPA)
– Underwriters Laboratories Inc (UL)
– International Standard Organisation (ISO)
– Australian Transport Council: The National Marine Safety Committee
– BSI – Kitemark License: Aerosol Fire Extinguishing Systems