Classifications

• • A—HUMAN NECESSITIES
  • A62—LIFE-SAVING; FIRE-FIGHTING
  • A62D—CHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS
  • A62D1/00—Fire-extinguishing compositions; Use of chemical substances in extinguishing fires
  • A62D1/0092—Gaseous extinguishing substances, e.g. liquefied gases, carbon dioxide snow
• • A—HUMAN NECESSITIES
  • A62—LIFE-SAVING; FIRE-FIGHTING
  • A62D—CHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS
  • A62D1/00—Fire-extinguishing compositions; Use of chemical substances in extinguishing fires
  • A62D1/0028—Liquid extinguishing substances
  • A62D1/0057—Polyhaloalkanes

Definitions

• the present invention relates to a gas mixture especially for use as a fire extinguishing agent, a fire extinguishing unit comprising the gas mixture, and a method for using the gas mixture.
• Fire extinguishing agents are consumed in large amounts all over the world for fire protection in airplanes, ships, computer rooms, laboratories etc. Fire extinguishing agents are used both at home and in industry. A large consumer, of course in addition to fire departments, are the armed forces which also use large quantities for training purposes.
• a standard agent for extinguishing fire is water, but in many cases water does greater damage than the fire itself, and besides water is unsuitable for extinguishing fire in e.g. electrical appliances.
• Carbon dioxide is also a fire extinguishing agent which is frequently used, but nor can this be used for all types of fire.
• Halon is a tradename and comprises a number of halogenated hydrocarbons.
• the halon compounds are different combinations of carbon, chlorine, fluorine and bromine.
• Halon 1301 Two types of halon gas have been predominant, Halon 1301 and Halon 1211.
• Halon 1301 has mainly been used in so-called total flooding systems
• Halon 1211 has been used for hand-held extinguishers and so-called mobile fire extinguishing units (wheel-mounted or in fire-engines).
• Halon 1211 has also been used in permanent installations, such as local application systems.
• a further important field of application for Halon 1211 is the protection of different types of vehicle, civilian as well as military. Generally, engine compartments and other machinery spaces are to be protected, but also personnel rooms are objects to be protected.
• halons are clean, effective and relatively non-toxic fire extinguishing agents, but in the 1970's it was considered to be proved that the halons as well as chlorofluorocarbons generally had a strongly ozone-depleting effect. Since then a large number of the countries in the world have decided and bound themselves to reduce and, in the long run, discontinue the production and use of halons. The world production of fire extinguishing agents and particularly the halons is enormous. Merely in respect of Halon 1211 which in the first place is an agent for small and medium size portable fire extinguishers, the 1986 production amounted to 20,000 tons. There is thus an increasing interest all over the world to find a replacement for the halons.
• the solution is the finding of a formula or a method for developing a replacement gas for different fields of application, while considering the specific parameters that apply to the application involved. To achieve this, the replacement gases must in future be custom-made for their purpose. A much larger number of variants will be necessary to meet all the applications which are of interest for this type of fire extinguishing agent (so-called clean fire extinguishing agents).
• One object of the present invention is to provide a gas mixture which is useful as a fire extinguishing agent in fire extinguishing systems of the total flooding system type.
• a further object of the present invention is to provide a gas mixture which is especially useful as a fire extinguishing agent which can replace prior art agents, e.g. the halons, and which is essentially just as effective but less harmful to the environment.
• One more object of the present invention is to provide a method for controlling, by means of the above-mentioned gas mixture, the spreading of a fire or embers.
• a still further object of the present invention is to provide a fire extinguishing unit containing the above-mentioned fire extinguishing agent.
• the fire extinguishing agent according to the invention comprises said gas mixture at a pressure of 2.5-50 bar, especially 15-50 bar.
• the method according to the invention is characterised in that such a gas mixture is applied to the fire or embers, or in the vicinity thereof.
• the gas mixture according to the invention comprises an inorganic compound as a basis.
• An especially preferred compound is SF6.
• the inventive gas mixture comprises, in addition to the basis, at least 1% by weight of a halogenated carbon or C1-C10 hydrocarbon, or mixtures thereof.
• the halogenated hydrocarbon of the gas mixture according to the present invention can be a C1-C10 hydrocarbon which is fully or partly halogenated.
• the halogen substituent is preferably F or Cl, and most advantageously F.
• Suitable halogenated hydrocarbons which can be utilised according to the invention are compounds from the groups CFC, HCFC, FC and HFC. Examples of such compounds are C2H2F4, CHF3, CHCl2CF3, CHClFCF3, CHF2CF3, CF3CHFCF3, C4F10, C5F12, C6F14, or mixtures thereof.
• These hydrocarbon compounds can be in the form of isomers, and the invention is also intended to comprise such isomers.
• Use can also be made of a halogenated carbon or mixtures of halogenated carbon and halogenated
• the third component of the gas mixture according to the invention is an inert gas, or mixtures thereof.
• the inert gas is generally present in a content of up to 5% by weight, but also higher contents can be used depending on the other components and conditions of application.
• inert gas is here meant a gas which at the temperatures which are normal in case of fire does not react or at least does not react in such a manner that the fire is promoted.
• the inert gas according to the invention functions as a propellant, and a suitable gas is e.g. N2, Ar, CO2, Kr and Xe, or mixtures thereof, preferably N2 or Ar.
• a suitable gas is e.g. N2, Ar, CO2, Kr and Xe, or mixtures thereof, preferably N2 or Ar.
• the inventive gas mixture comprises an inorganic compound as a basis to which at least 1% by weight of a halogenated carbon or C1-C10 hydrocarbon, or mixtures thereof, is added. Furthermore, the mixture contains about one % by weight, usually up to 5% by weight, of a propellant. Examples of gas mixtures according to the invention are such containing about 30-50% by weight, suitably about 40-45% by weight, of a basis, about 50-70% by weight, suitably 55-60% by weight, of a halogenated carbon or hydrocarbon, or mixtures thereof, and about 1% by weight of a propellant, the mixture comprising a total of 100% by weight.
• a preferred combination of three components for a room system or sprinkler system is SF6 + (CF3CH2F + CHF3) + Ar, or some other propellant; working pressure 15-50 bar.
• the gas mixture according to the invention is prepared by simple mixing of the different components in proportions as desired.
• the agent according to the invention can be used in all types of fire extinguishing system.
• the agent can also be used for all types of fire.
• the three or two components are combined owing to the field of application and the type of fire extinguishing system involved.
• the agent can be used in existing fire extinguishing systems, in many cases merely by changing a gasket or nozzle.
• the gas mixture according to the invention which is especially useful in total flooding systems, has especially good effect when used in combination with a nozzle providing initial rotation of the gas mixture, which causes agitation and homogeneity in the mixture of fire extinguishing agent and the air in the fire area, i.e. the room in which the fire takes place.
• suitable nozzles are those manufactured by BETE, designated TF-XX-FC.
• Convenient nozzles are also manufactured by American Spray System.
• the agent according to the present invention has proved to be essentially as effective as the halons, and sometimes even more effective. They are also substantially less harmful to the environment as compared to the halons.
• the present invention also relates to a fire extinguishing unit comprising a container for the fire extinguishing agent, and the above-mentioned fire extinguishing agent at a certain working pressure.
• Portable fire extinguishers normally operate at a pressure of 5-15 bar, and larger systems, for example sprinkler systems, normally at a pressure of 15-50 bar.
• the present invention relates to a method for controlling the spreading of a fire or embers by applying a gas mixture as stated above.
• the gas mixture according to the invention must pass a nozzle member which is designed and optimised to the fields of application where the agent is intended to be used.
• the streaming effect of the extinguishing agent is in most cases of secondary importance. Instead the dispersion and evaporation of the gas mixture should be as quick as possible.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Business, Economics & Management (AREA)
• Emergency Management (AREA)
• Fire-Extinguishing Compositions (AREA)
• Fire-Extinguishing By Fire Departments, And Fire-Extinguishing Equipment And Control Thereof (AREA)
• Fireproofing Substances (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

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Family Applications (1)

Country Status (2)

Cited By (3)

Citations (8)

• 1993
  • 1993-03-31 SE SE9301099A patent/SE523660C2/sv not_active IP Right Cessation
• 1994
  • 1994-03-31 EP EP94850052A patent/EP0617983A1/fr not_active Withdrawn

Patent Citations (8)

Non-Patent Citations (2)

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