Classifications

• • A—HUMAN NECESSITIES
  • A62—LIFE-SAVING; FIRE-FIGHTING
  • A62C—FIRE-FIGHTING
  • A62C35/00—Permanently-installed equipment
  • A62C35/02—Permanently-installed equipment with containers for delivering the extinguishing substance
  • A62C35/023—Permanently-installed equipment with containers for delivering the extinguishing substance the extinguishing material being expelled by compressed gas, taken from storage tanks, or by generating a pressure gas
• • A—HUMAN NECESSITIES
  • A62—LIFE-SAVING; FIRE-FIGHTING
  • A62C—FIRE-FIGHTING
  • A62C13/00—Portable extinguishers which are permanently pressurised or pressurised immediately before use
  • A62C13/003—Extinguishers with spraying and projection of extinguishing agents by pressurised gas
• • A—HUMAN NECESSITIES
  • A62—LIFE-SAVING; FIRE-FIGHTING
  • A62C—FIRE-FIGHTING
  • A62C3/00—Fire prevention, containment or extinguishing specially adapted for particular objects or places
  • A62C3/002—Fire prevention, containment or extinguishing specially adapted for particular objects or places for warehouses, storage areas or other installations for storing goods
  • A62C3/004—Fire prevention, containment or extinguishing specially adapted for particular objects or places for warehouses, storage areas or other installations for storing goods for freezing warehouses and storages
• • A—HUMAN NECESSITIES
  • A62—LIFE-SAVING; FIRE-FIGHTING
  • A62C—FIRE-FIGHTING
  • A62C99/00—Subject matter not provided for in other groups of this subclass
  • A62C99/0009—Methods of extinguishing or preventing the spread of fire by cooling down or suffocating the flames
  • A62C99/0018—Methods of extinguishing or preventing the spread of fire by cooling down or suffocating the flames using gases or vapours that do not support combustion, e.g. steam, carbon dioxide
• • A—HUMAN NECESSITIES
  • A62—LIFE-SAVING; FIRE-FIGHTING
  • A62C—FIRE-FIGHTING
  • A62C3/00—Fire prevention, containment or extinguishing specially adapted for particular objects or places
  • A62C3/07—Fire prevention, containment or extinguishing specially adapted for particular objects or places in vehicles, e.g. in road vehicles
  • A62C3/08—Fire prevention, containment or extinguishing specially adapted for particular objects or places in vehicles, e.g. in road vehicles in aircraft

Definitions

• the present invention relates to a fire extinguisher comprising an extinguishing agent with a low concentration of saturating vapor.
• Halons are brominated halogenated chemical compounds.
• the Halons have the advantage of having a high vapor pressure even cold allowing to have even in the low temperature conditions a gas concentration greater than the extinction concentration.
• the extinguishing concentration is a quantity indicated by the supplier of that extinguishing agent. It indicates the minimum volume concentration of extinguishing agent to be delivered to the atmosphere in order to extinguish a fire related to the combustion of a given material.
• the extinguishing concentration is commonly evaluated according to ISO 14520 by cup-burner test.
• the extinction concentration is given as a temperature independent quantity.
• Halons are polluting products, sources of the depletion of the ozone layer whose use is the object of increasingly strict regulatory prohibitions. It is also expected that Halons will no longer be available in the 2030s.
• the use of Halon as an extinguishing agent is therefore an environmentally unsatisfactory interim solution that is desirable to replace.
• various extinguishing agents that do not have the adverse effects of Halon have been developed.
• Such extinguishing agents have a low saturation vapor pressure and are more environmentally friendly than Halons.
• An example of an existing low saturation vapor pressure suppressant is FK-5-1-12. It is also known as Novec TM 1230. These extinguishing agents work with known extinguishing devices.
• the manufacturer specifies a minimum temperature of use below which the agent condenses before reaching this effective concentration and therefore can not extinguish a fire.
• the manufacturer specifies a minimum temperature of use below which the agent condenses before reaching this effective concentration and therefore can not extinguish a fire.
• the supplier explicitly states that its product is not usable at temperatures lower than or equal to -10 ° C. Below this temperature limit of use, the saturating vapor concentration of these extinguishing agents is lower than their extinction concentration. In this case, the gaseous extinguishing agent in the gaseous state with the known devices is not present in sufficient concentration to extinguish the fire when the temperature is too low, hence the existence of this temperature limit use.
• the invention aims, according to a first embodiment, a fire extinguisher comprising at least:
• a body defining a storage chamber containing an extinguishing agent, a gas generator configured to pressurize the extinguishing agent in order to distribute it outside the body through an outlet orifice,
• the fire extinguisher being characterized in that the outlet orifice is provided with a misting nozzle, and in that the extinguishing agent has a solidification temperature below -10 ° C, the concentration of saturating vapor of the extinguishing agent taken at -10 ° C and at 1 bar being lower than the extinction concentration of the extinguishing agent determined according to ISO 14520 for a heptane fire at 1 bar.
• the "saturating vapor concentration of the extinguishing agent taken at -10 ° C and 1 bar" is equal to the following ratio: [saturated vapor pressure of the extinguishing agent at -10 ° C ] / [1 bar].
• the extinguishing concentration can be determined according to ISO standard 14520, 3rd edition published in December 2015.
• the invention also aims, according to a second embodiment, a fire extinguisher comprising at least:
• a body defining a storage chamber containing an extinguishing agent
• a gas generator configured to pressurize the extinguishing agent in order to distribute it outside the body through an outlet orifice
• the fire extinguisher being characterized in that the outlet orifice is provided with a misting nozzle, and in that the extinguishing agent has a solidification temperature of less than -10 ° C and a pressure of saturated steam less than or equal to 70 mbar at -10 ° C.
• the invention implements, in its two embodiments described above, an extinguishing agent with a low concentration of saturating vapor, at low temperature, with regard to the need for extinction.
• the first embodiment is directed to extinguishing agents, at any saturated vapor pressure, for which the saturation vapor concentration at 1 bar and at -10 ° C is lower than the quenching concentration.
• the second embodiment is specifically aimed at extinguishing agents with low saturation vapor pressure at -10 ° C. These extinguishing agents have in fact a low saturation vapor concentration with regard to the need for extinction at low temperature.
• the fire extinguisher implements a misting nozzle which makes it possible to generate a mist formed by fine liquid droplets of the extinguishing agent during use.
• a misting nozzle is a type of ejection nozzle known per se (referred to in English as the "misting nozzle").
• the inventors found that fine liquid droplets were properly transported to the fire zone by the flow of gas, at low temperature.
• the invention makes it possible to extinguish below the limit temperature of use indicated by the manufacturer of the extinguishing agent because both the liquid phase (fine droplets) and the gaseous phase of the extinguishing agent are transported to the fire zone and participate in extinction.
• quenching is provided in the invention by a two-phase quenching agent stream prior to contact with the fire zone.
• the invention thus provides a solution for achieving fire suppression at low temperature while employing a quenching agent with low concentration of saturating vapor.
• This is a problem of which no suitable solution is currently proposed in the state of the art, the use of low saturating vapor dehumidifying agents at low temperature being even explicitly indicated as to avoid by some suppliers.
• the inventors have found that the extinction performance obtained at low temperature using the fire extinguisher according to the invention were particularly high, and more particularly higher than those obtained at higher temperatures. This allows in particular to use a lower concentration for the extinguishing agent to extinguish a fire at low temperatures, and thus reduce the weight of the fire extinguisher.
• an extinguishing agent with a low saturation vapor pressure is advantageous because it is not very volatile, and therefore has a low impact on the environment.
• the ratio, taken at the temperature of 20 ° C, [density of the extinguishing agent] / [surface tension extinguishing agent - air] is greater than or equal to 120000 s 2 / m 3 .
• Such a characteristic makes it possible to reduce the size of the droplets formed and to further increase the quantity of extinguishing agent transported by the flow towards the fire at low temperature, thus improving the quenching efficiency.
• the extinguishing agent has a viscosity at -10 ° C. of less than or equal to 2 centistokes.
• Such a feature is advantageous in order to decrease the pressure required to deliver a given liquid agent flow rate, thereby further facilitating the flow of extinguishing agent to the fire zone.
• the gas generator is configured to impose a maximum pressure greater than or equal to 3 bar, for example greater than or equal to 7 bar, to the extinguishing agent.
• Such a characteristic makes it possible to reduce the size of the droplets formed and to further increase the quantity of extinguishing agent transported by the flow towards the fire at low temperature, thus improving the quenching efficiency.
• the misting nozzle is capable of generating liquid droplets of extinguishing agent of size less than or equal to 50 ⁇ m at -10 ° C.
• Such a characteristic advantageously makes it possible, by using particularly fine droplets, to further improve the extinction efficiency at low temperature and thus to limit the effective concentration to extinguish the fire.
• the misting nozzle may be capable of generating liquid droplets of extinguishing agent with a size of less than or equal to 10 ⁇ m at -10.degree.
• the gas generator comprises a pyrotechnic gas generator.
• a pyrotechnic gas generator is advantageous with respect to the use of a pressurized gas cylinder in order, on the one hand, to limit the sensitivity to the temperature of the pressure generated and, on the other hand to obtain a pressure profile imposed on the quenching agent which is almost constant as a function of time, thus further improving the quenching efficiency at low temperature.
• the gas generator comprises a pressurized gas cylinder.
• the gas generator is present in a pressurization chamber separated from the storage chamber by a movable wall, the gas generator being configured to move the movable wall in order to distribute the agent. extinguishing outside the body.
• the gas generator may be present in the storage chamber.
• the invention also relates to an aircraft equipped with a fire extinguisher as described above
• the invention also relates to a method of extinguishing a fire in an environment at a temperature of less than or equal to -10 ° C., comprising at least one step of distributing the extinguishing agent using a extinguisher as described above.
• the treated fire may be in an environment at a temperature of less than or equal to -55 ° C.
• FIG. 1 is a diagrammatic longitudinal section of an exemplary extinguisher according to the invention
• FIG. 2 is a perspective view of part of the extinguisher of FIG. 1, and
• FIGS. 3A and 3B show the displacement of the mobile wall in the example of the fire extinguisher of FIG. 1 during the distribution of the extinguishing agent.
• FIG. 1 shows an example of a fire extinguisher according to the invention.
• the device 1 comprises a body 2 extending along a longitudinal axis X and defining a storage chamber 4 in which an extinguishing agent (not shown) is present.
• the extinguishing agent may be present in the liquid state. In the case where the fire extinguisher is used at a high temperature, the extinguishing agent may be in the gaseous state.
• the storage chamber 4 may have a non-zero free volume (i.e. a non-zero volume not occupied by the liquid medium containing the extinguishing agent). Alternatively, the entire volume of the storage chamber is occupied by the liquid medium containing the extinguishing agent before the start of dispensing.
• extinguishing agent that can be used, mention may for example be made of FK-5-1-12 or Novec TM 1230 (perfluoro-4- (trifluoromethyl) -3-pentanone).
• the extinguishing agent may have a saturating vapor pressure of less than or equal to 70 mbar at -10 ° C.
• the FK-5-1-12 checks in particular this condition.
• the extinguishing agent has a solidification temperature below -10 ° C. It is thus in the liquid state when it is distributed at -10 ° C.
• the solidification temperature of the extinguishing agent may in particular be less than or equal to -55 ° C. in certain extreme cases.
• the extinguishing agent may have a viscosity at -10 ° C of less than or equal to 2 centistokes.
• the body 2 further defines, in the illustrated example, a pressurizing chamber 5 comprising a gas generator 20.
• the gas generator 20 is a pyrotechnic gas generator.
• the gas generator may be a pressurized gas cartridge.
• the gas generator comprises at least one housing in which a pyrotechnic charge is present. More precisely, in the example illustrated in FIG. 1, the gas generator 20 comprises an initiator 26 making it possible to initiate the combustion of the relay charge 27 which will trigger the combustion of the pyrotechnic charge 23 in order to generate the setting gas. pressure.
• the pyrotechnic charge 23 may be in the form of a monolithic block or a granular material.
• the pyrotechnic charge 23 may have the same composition as the pyrotechnic charges typically used in gas generators for airbags.
• the pyrotechnic charge 23, however, has dimensions adapted to the intended operating time (i.e. larger than those of the pyrotechnic charges used in gas generators for airbags).
• Pyrotechnic compositions that may be used in the gas generator 20 have in particular been described in the following documents: US 5,608,183, US 6,143,102, FR 2,975,097, FR 2,964,656, FR 2,950,624, FR 2 915 746, FR 2 902 783, FR 2 899 227, FR 2 892 117, FR 2 891 822, FR 2 866 022, FR 2 772 370 and FR 2 714 374.
• the gas generator may comprise one or more pyrotechnic charges. .
• the gas generator 20 may be electrically tripped by application of an electric current across the initiator or mechanical (triggering percussion). In the case of a mechanical trigger, a striker strikes the ignition device. In all cases, the initiation of the ignition device leads to the combustion of the pyrotechnic charge 23 and the release of the gases from the combustion.
• the gas generator When actuated in a medium at a temperature of less than or equal to -10 ° C, the gas generator can be configured to impose the extinguishing agent a maximum pressure greater than or equal to 3 bar, for example 7 bar .
• This maximum pressure can be understood between 3 bar and 30 bar, for example between 7 bar and 30 bar. It is general knowledge of those skilled in the art to design a gas generator to allow the application of the desired maximum pressure value.
• the pressurizing chamber 5 is separated from the storage chamber 4 by a movable wall 7 in the example illustrated.
• the body 2 has, in the example shown, a symmetrical shape of revolution, here cylindrical. Of course, the invention is not limited to such shapes for the body 2.
• the body 2 has a side wall 2a extending along the longitudinal axis X of the body 2 and surrounding the storage chamber 4.
• the side wall 2a of the body 2 further surrounds the pressurizing chamber 5.
• the body 2 further comprises a first bottom wall 2b and a second bottom wall 2c.
• the first and second bottom walls 2b and 2c delimit longitudinally the body 2.
• the first bottom wall 2b delimits the storage chamber 4.
• the first bottom wall 2b has at least one outlet orifice 10 configured to deliver the agent.
• the second bottom wall 2c delimits the pressurizing chamber 5.
• the pressurizing chamber 5 is located between the movable wall 7 and the second bottom wall 2c.
• the storage chamber 4 is located between the first bottom wall 2b and the movable wall 7, the latter defining the storage chamber 4.
• the movable wall 7 may be formed of a metallic material, for example aluminum.
• the movable wall 7 consists of a single material and this in order to further simplify the manufacturing process of the device 1.
• the movable wall 7 is configured to seal the storage chamber 4 from the pressurizing chamber. 5.
• the movable wall 7 is configured to communicate to the extinguishing agent present in the storage chamber 4 the pressure imposed by the gas generated in the pressurizing chamber 5.
• the direction of application of the pressure by the movable wall 7 on the extinguishing agent to be distributed is substantially parallel to the longitudinal axis X of the body 2.
• the movable wall 7 extends transversely, for example perpendicularly, with respect to the longitudinal axis X of the body 2.
• the movable wall 7 extends over the entire internal diameter D s of the storage chamber 4.
• the movable wall 7 is configured not to be broken under the effect of the pressure imposed by the gas generated in the pressurizing chamber 5.
• the device 1 may further comprise a shutter 15 sealingly closing the outlet orifice 10 and configured to allow the exit of the extinguishing agent outside the body 2 when the pressure in the storage chamber 4 exceeds a predefined value.
• the shutter 15 is configured to prevent, when in a first configuration, the output of the extinguishing agent outside the body 2, the shutter 15 is further configured to proceed to a second configuration when the pressure in the storage chamber 4 exceeds a predefined value, this second configuration of the shutter 15 allowing the exit of the extinguishing agent outside the body 2.
• the shutter 15 can for example, be in the form of a membrane configured to yield when the pressure in the storage chamber 4 exceeds a predefined value.
• the shutter 15 may, for example, be an aluminum or alloy membrane of Inconel® type.
• a misting nozzle 18 is attached to the device 1 at the outlet port 10 of said device.
• the misting nozzles are nozzles known per se. These are nozzles for generating fine droplets, for example of size less than or equal to 50 pm, or even 10 pm.
• the misting nozzle 18 (in English “misting nozzle”) generates a mist comprising liquid droplets of the extinguishing agent.
• An example of a usable misting nozzle is the nozzle sold under the reference "DFN Misting Nozzle” by the company IC Spray. This example of a nozzle makes it possible to generate liquid droplets of extinguishing agent of size less than or equal to 50 ⁇ m at -10 ° C.
• the gas generator 20 is first actuated to pressurize the chamber 5. This excess pressure created in the chamber 5 is transmitted by the movable wall 7 to the extinguishing agent present in the storage chamber 4. Once a preset value has been reached for the pressure in the storage chamber 4, the shutter 15 goes into a second configuration allowing the exit of the extinguishing agent outside the body 2 through the outlet port 10.
• the movable wall 7 is moved to the first bottom wall 2b to cause the distribution of the extinguishing agent.
• the movable wall 7 is set in motion along the longitudinal axis X.
• the extinguishing agent is dispensed outside the fire extinguisher by the misting nozzle 18 in order to obtain a mist 19 of fine liquid droplets of extinguishing agent.
• the extinguisher according to the invention is specially adapted to extinguish a fire at low temperature.
• the agent can be conventionally transported in gaseous form and it also extinguishes the fire in its gaseous form.
• the fire extinguisher can be used in an environment at a pressure equal to 1 bar, or less than 1 bar.
• the movable wall 7 is configured to move without deformation during the distribution of the extinguishing agent.
• the movable wall 7 has a piston effect.
• the face of the movable wall 7 located on the side of the pressurizing chamber 5 is subjected to the pressure of the generated gas, this pressure is communicated to the face of the movable wall 7 located on the side of the storage chamber 4 to allow the distribution of the extinguishing agent outside the body 2.
• the movable wall 7 causes, during its movement, the distribution extinguishing agent outside the body 2 in the manner of a syringe in the illustrated example.
• the invention can also be implemented with a pressurized gas bottle, although the use of a pyrotechnic generator is preferred.

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• Health & Medical Sciences (AREA)
• Public Health (AREA)
• Business, Economics & Management (AREA)
• Emergency Management (AREA)
• Engineering & Computer Science (AREA)
• Operations Research (AREA)
• Fire-Extinguishing By Fire Departments, And Fire-Extinguishing Equipment And Control Thereof (AREA)
• Fire-Extinguishing Compositions (AREA)
• Feeding, Discharge, Calcimining, Fusing, And Gas-Generation Devices (AREA)

Applications Claiming Priority (2)

Publications (3)

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Family Applications (1)

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• 2018
  • 2018-02-20 FR FR1851428A patent/FR3077989B1/fr active Active
• 2019
  • 2019-02-18 EP EP19710061.3A patent/EP3755437B1/de active Active
  • 2019-02-18 WO PCT/FR2019/050363 patent/WO2019162603A1/fr not_active Ceased
  • 2019-02-18 JP JP2020566332A patent/JP7308230B2/ja active Active
  • 2019-02-18 CN CN201980023033.9A patent/CN112004580A/zh active Pending
  • 2019-02-18 US US16/971,178 patent/US11383112B2/en active Active

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