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Automatic fire suppression systems control and extinguish fires without human intervention. Examples of automatic systems include fire sprinkler system, gaseous fire suppression, and condensed aerosol fire suppression. When fires are extinguished in the early stages loss of life is minimal since 93% of all fire-related deaths occur once the fire has progressed beyond the early stages. [1] [2]
Today there are numerous types of automatic fire suppression systems and standards for each one. [3] Systems are as diverse as the many applications. [4] [5] In general, however, automatic fire suppression systems fall into two categories: engineered and pre-engineered systems. [6]
By definition, an automatic fire suppression system can operate without human intervention. To do so it must possess a means of detection, actuation and delivery. In many systems, detection is accomplished by mechanical or electrical means. Mechanical detection uses fusible-link or thermo-bulb detectors. These detectors are designed to separate at a specific temperature and release tension on a release mechanism. Electrical detection uses heat detectors equipped with self-restoring, normally-open contacts which close when a predetermined temperature is reached. Remote and local manual operation is also possible. Actuation usually involves either a pressurized fluid and a release valve, or in some cases an electric pump. Delivery is accomplished by means of piping and nozzles. Nozzle design is specific to the agent used and coverage desired.
Water is the most prevalent fire suppression agent in use worldwide. However, the use of water does have some limitations, which can range from inadequate supplies (particularly in less developed regions) to operations and processes which are highly susceptible to water damage. In some cases, certain contents or processes (such as water-reactive chemicals or metals, molten materials, etc.) are truly incompatible with water; water discharge could lead to explosion. In these instances, alternative chemical compounds, inert gases and similar can be utilized for fire suppression as outlined below:
| Agent | Primary ingredient | Applications |
|---|---|---|
| HFC 227ea (e.g. FM-200) | Heptafluoropropane | Electronics, medical equipment, production equipment, libraries, data centers, medical record rooms, server rooms, oil pumping stations, engine compartments, telecommunications rooms, switch rooms, engine and machinery spaces, pump rooms, control rooms |
| FK-5-1-12 (3M Novec 1230 Fire Protection Fluid) | Fluorinated ketone | Electronics, medical equipment, production equipment, libraries, data centers, medical record rooms, server rooms, oil pumping stations, engine compartments, telecommunications rooms, switch rooms, engine and machinery spaces, pump rooms, control rooms |
| IG-01 | Argon | Same applications as FM-200 and Novec 1230 fluid; less Class B style hazards |
| IG-55 | Argon (50%) and nitrogen (50%) | See IG-01 |
| IG-100 | Nitrogen | See IG-01 |
| IG-541 | Argon (40%), nitrogen (52%) and carbon dioxide (8%) | See IG-01 |
| Carbon dioxide | Carbon dioxide | Non-occupied control rooms, coating operations, paint lines, dust collectors, transformer vaults, live electrical equipment, flammable liquids, commercial fryers |
| FE-13 | Fluoroform | Police evidence freezers, inerting natural gas pumping stations or trains/trucks/cranes operating in cold weather, electronics, medical equipment, production equipment, libraries, data centers, medical record rooms, server rooms, oil pumping stations, engine compartments, telecommunications rooms, switch rooms, engine and machinery spaces, pump rooms, control rooms |
| Wet chemical | Potassium carbonate | Commercial kitchens |
| ABC dry chemical | Monoammonium phosphate | Paint booths, dip tanks, coating operations, flammable liquid storage areas, paint mixing areas, exhaust ducts |
| Regular dry chemical | Sodium bicarbonate | Gasoline, propane and solvents, live electrical equipment, flammable liquids |
| Foam | Synthetic detergent, polysaccharide, fluoroakyl suffaccant | Flammable liquids |
| Purple K dry chemical | Potassium bicarbonate | High hazard commercial and industrial applications, especially with flammable liquids |
| Solid aerosol particulate | Potassium nitrate | Used in condensed aerosol fire suppression, high hazard commercial and industrial applications, no ozone depletion or global warming potential |
| Halotron 1 | 2,2-dichloro-1,1,1-trifluoroethane | Live electrical equipment, flammable liquids |
| Water mist | Water | All classes of fire (A, B, C, F): ordinary flammables (Paper, wood, cloth), flammable liquids, kitchen fires (K, F class), electrical fires |
| Water | Water | Ordinary flammables (Paper, wood, cloth) |
Despite their effectiveness, chemical fire extinguishing agents are not without disadvantages. In the early 20th century, carbon tetrachloride was extensively used as a dry cleaning solvent, a refrigerant and as a fire extinguishing agent. In time, it was found carbon tetrachloride could lead to severe health effects. [7] From the mid-1960s Halon 1301 was the industry standard for protecting high-value assets from the threat of fire. Halon 1301 had many benefits as a fire suppression agent; it is fast-acting, safe for assets and required minimal storage space. Halon 1301's major drawbacks are that it depletes atmospheric ozone and is potentially harmful to humans. Since 1987, some 191 nations have signed The Montreal Protocol on Substances That Deplete the Ozone Layer. The Protocol is an international treaty designed to protect the ozone layer by phasing out the production of a number of substances believed to be responsible for ozone depletion. Among these were halogenated hydrocarbons often used in fire suppression. As a result, manufacturers have focused on alternatives to Halon 1301 and Halon 1211 (halogenated hydrocarbons). A number of countries have also taken steps to mandate the removal of installed Halon systems. Most notably these include Germany and Australia, the first two countries in the world to require this action. In both of these countries complete removal of installed Halon systems has been completed except for a very few essential-use applications. The European Union is currently undergoing a similar mandated removal of installed Halon systems. [8] [9] [10] [11]
The first fire extinguisher patent was issued to Alanson Crane of Virginia on Feb. 10, 1863. [12] The first fire sprinkler system was patented by H.W. Pratt in 1872. But the first practical automatic sprinkler system was invented in 1874 by Henry S. Parmalee of New Haven, CT. He installed the system in a piano factory he owned.
Since the early 1990s manufacturers have successfully developed safe and effective Halon alternatives. These include DuPont's FM-200, American Pacific's Halotron, FirePro's FPC Compound, Plumis’ Automist and 3M's Novec 1230 Fire Protection Fluid. Generally, the Halon replacement agents available today fall into two broad categories, in-kind (gaseous extinguishing agents) or not in-kind (alternative technologies). In-kind gaseous agents generally fall into two further categories, halocarbons and inert gases. Not in-kind alternatives include such options as water mist or the use of early warning smoke detection systems.
A fire sprinkler system is an active fire protection method, consisting of a water supply system providing adequate pressure and flowrate to a water distribution piping system, to which fire sprinklers are connected. Although initially used only in factories and large commercial buildings, systems for homes and small buildings are now available at a cost-effective price.
Bromochlorodifluoromethane (BCF), also referred to by the code numbers Halon 1211 and Freon 12B1, is a haloalkane with the chemical formula CF2ClBr. It is used for fire suppression, especially for expensive equipment or items that could be damaged by the residue from other types of extinguishers. It is stored as a liquid under pressure and vaporizes when discharged to suppress fires. The use of halons, including Halon 1211, has decreased over time due to their adverse impact on the ozone layer. Alternatives have been developed to mitigate environmental concerns while still providing effective fire suppression capabilities.
Bromotrifluoromethane, commonly referred to by the code numbers Halon 1301, R13B1, Halon 13B1 or BTM, is an organic halide with the chemical formula CBrF3. It is used for gaseous fire suppression as a far less toxic alternative to bromochloromethane.
Halomethane compounds are derivatives of methane with one or more of the hydrogen atoms replaced with halogen atoms. Halomethanes are both naturally occurring, especially in marine environments, and human-made, most notably as refrigerants, solvents, propellants, and fumigants. Many, including the chlorofluorocarbons, have attracted wide attention because they become active when exposed to ultraviolet light found at high altitudes and destroy the Earth's protective ozone layer.
Gaseous fire suppression, also called clean agent fire suppression, is the use of inert gases and chemical agents to extinguish a fire. These agents are governed by the National Fire Protection Association (NFPA) Standard for Clean Agent Fire Extinguishing Systems – NFPA 2001 in the US, with different standards and regulations elsewhere. The system typically consists of the agent, agent storage containers, agent release valves, fire detectors, fire detection system, agent delivery piping, and agent dispersion nozzles.
1,1,1,2,3,3,3-Heptafluoropropane, also called heptafluoropropane, HFC-227ea, HFC-227 or FM-200, as well as apaflurane (INN), is a colourless, odourless gaseous halocarbon commonly used as a gaseous fire suppression agent.
Trifluoroiodomethane, also referred to as trifluoromethyl iodide is a halomethane with the formula CF3I. It is an experimental alternative to Halon 1301 (CBrF3) in unoccupied areas. It would be used as a gaseous fire suppression flooding agent for in-flight aircraft and electronic equipment fires.
Fire protection is the study and practice of mitigating the unwanted effects of potentially destructive fires. It involves the study of the behaviour, compartmentalisation, suppression and investigation of fire and its related emergencies, as well as the research and development, production, testing and application of mitigating systems. In structures, be they land-based, offshore or even ships, the owners and operators are responsible to maintain their facilities in accordance with a design-basis that is rooted in laws, including the local building code and fire code, which are enforced by the authority having jurisdiction.
Fire suppression systems are used to extinguish, control, or in some cases, entirely prevent fires from spreading or occurring. Fire suppression systems have an incredibly large variety of applications, and as such, there are many different types of suppression systems for different applications being used today. Of these, there are some that are still in use but are no longer legal to manufacture and produce.
Active fire protection (AFP) is an integral part of fire protection. AFP is characterized by items and/or systems, which require a certain amount of motion and response in order to work, contrary to passive fire protection.
A fire class is a system of categorizing fire with regard to the type of material and fuel for combustion. Class letters are often assigned to the different types of fire, but these differ between territories; there are separate standards for the United States, Europe, and Australia. The fire class is used to determine the types of extinguishing agents that can be used for that category.
Bromochloromethane or methylene bromochloride and Halon 1011 is a mixed halomethane. It is a heavy low-viscosity liquid with refractive index 1.4808.
The Centre for Fire, Explosive and Environment Safety (CFEES) is an Indian defence laboratory of the Defence Research and Development Organisation (DRDO). Located in Timarpur, Delhi, its main function is the development of technologies and products in the area of explosive, fire and environmental safety. CFEES is organised under the Armaments Directorate of DRDO. The present director of CFEES is Arvind Kumar
PhostrEx is a fire suppression agent developed for use in aviation applications to replace halon, a greenhouse gas (GHG). It was developed by Eclipse Aviation for use aboard their Eclipse 500 very light jets as an engine fire suppression system, and is now being marketed to other aviation manufacturers.
A fire extinguisher is a handheld active fire protection device usually filled with a dry or wet chemical used to extinguish or control small fires, often in emergencies. It is not intended for use on an out-of-control fire, such as one which has reached the ceiling, endangers the user, or otherwise requires the equipment, personnel, resources or expertise of a fire brigade. Typically, a fire extinguisher consists of a hand-held cylindrical pressure vessel containing an agent that can be discharged to extinguish a fire. Fire extinguishers manufactured with non-cylindrical pressure vessels also exist but are less common.
Pentafluoroethane is a fluorocarbon with the formula CF3CHF2. Pentafluoroethane is currently used as a refrigerant (known as R-125) and also used as a fire suppression agent in fire suppression systems.
Condensed aerosol fire suppression is a particle-based method of fire extinction. It is similar to but not identical to dry chemical fire extinction methods, using an innovative pyrogenic, condensed aerosol fire suppressant. It is a highly effective fire suppression method for class A, B, C, E and F. Some aerosol-generating compounds produce a corrosive by-product that may damage electronic equipment, although later generations lower the effect.
Clean agent FS 49 C2 is an environmentally engineered, human safe, fast acting Clean Agent fire extinguishing gas for gaseous fire suppression installed in a suited fire suppression system. The gas consists of tetrafluoroethane, pentafluoroethane and carbon dioxide.
Graviner is a British engineering company that makes oxygen and fire extinguishing systems for civil and military aircraft. The name is a portmanteau of gravity and inertia.
A spark extinguishing system is used for preventive fire protection. A spark extinguishing system can detect and eliminate ignition sources before a fire or dust explosion occurs. Systems for grinding, chopping, drying, cooling and pressing materials including their pneumatic or mechanical transport and extraction systems and facilities for separation or storage purposes, also dust collectors, filters, cyclones, silos, and hoppers are especially at risk.
