Classifications

• • 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
• • 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
  • A62C5/00—Making of fire-extinguishing materials immediately before use
  • A62C5/02—Making of fire-extinguishing materials immediately before use of foam
  • A62C5/022—Making of fire-extinguishing materials immediately before use of foam with air or gas present as such

Definitions

• the present invention relates to a fire fight ⁇ ing installation comprising a liquid source, a pump connected to said liquid source and preferably having a high liquid pressure and comparatively small flow, and a gas source connected by way of a line to an outlet line of the pump for mixing gas with outbound extinguishing liquid delivered to spray heads.
• a liquid source for example a kerosene fire in an aircraft jet engine undergoing an engine test in a hangar designed for that purpose
• a gas source connected by way of a line to an outlet line of the pump for mixing gas with outbound extinguishing liquid delivered to spray heads.
• Certain kinds of gasoline fires for example a kerosene fire in an aircraft jet engine undergoing an engine test in a hangar designed for that purpose, are nearly impossible to extinguish even by means of strong mist-like jets of liquid, as suggested for example in international patent application PCT/FI92/00155.
• Such a jet engine fire will only go out when the entire hangar, which may typically have a volume
• the liquid mist can in principle be produced with apparatus as described in international patent application PCT/FI92/00317.
• an outgoing ascension tube of a hydraulic accumulator is provided with wall apertures, so that the propellent gas of the accumulator initially drives out liquid only, and after the liquid level has sunk to be even with the uppermost tube wall aperture, mixing of propellent gas into the outbound liquid is gradually started as the liquid level sinks and more tube wall apertures are exposed.
• the installation of the invention is primarily characterized in that the gas source is connected to the outlet line of the pump for producing a finely divided liquid mist.
• the purpose of the gas is to enable fine division of the liquid droplets, which produces a finely divided liquid mist.
• the gas source is arranged to mix gas in the outlet line of the pump with at least sub ⁇ stantially the same high pressure as the pump.
• the gas source can advantageously be consti ⁇ tuted by a plurality of compressed-gas bottles coupled in parallel.
• the gas may be nitrogen, argon, air, etc. In principle, any suitable gas may be used.
• the con ⁇ tents of the compressed-gas bottles may be partially in liquid form, depending on the type of gas employed.
• the charge pressure of the gas bottles like the operating pressure of the pump, may be approximately 50-200 bar, even though both lower and higher pressures are pos ⁇ sible.
• a comparatively small pump flow in this con ⁇ text means that the flow is smaller than the flow capacity of the relevant sprinklers or spray heads at maximum operating pressure.
• the pump flow may be 10- 80%, preferably 20-50% of the total flow of extin- guishing fluid at maximum operating pressure.
• the gas source preferably a plurality of gas bottles, is arranged at a first stage to empty one or more liquid tanks in order to at least suppress the fire, the gas pressure being so adapted that when the liquid tanks are empty, the gas pressure is at least substan- tially as high as the operating pressure of the pump.
• Figure 1 shows an embodiment for immediate production of finely divided liquid mist.
• Figure 2 shows an embodiment for initial spraying of liquid and subsequent production of finely divided liquid mist and foam.
• the embodiment shown in Figure 1 comprises a pump 1, having an outlet line 2 leading to a plurality of spray heads 3.
• the pump 1 may be a high-pressure pump with a typical operating pressure of 50-200 bar.
• a plurality of compressed-gas bottles 4 coupled in parallel are connected to the outlet line 2 of the pump via a check valve 5 ensuring that no liquid will enter the compressed-gas bottles 4.
• a check valve 6 mounted in the outlet line 2 of the pump ensures likewise that the gas will be correctly routed.
• the compressed-air bottles 4 can be filled with nitrogen.
• the pressure of the gas in the compressed-gas bottles can suitably be 100-300 bar.
• a throttle 31 has been coupled in the line 30 between the compressed-gas bottles and the outlet line 2 of the pump.
• the purpose of the throttle 31 is to enable adjustment of the mixing ratio of liquid and gas in the extinguishing fluid flowing in the outlet line 2.
• the throttle 31 is not indispensable. It could be contemplated that the mixing ratio could be adjusted by variously dimensioning the line 30.
• reference numeral 11 denotes a pump aggregate that can comprise for example two 11 kW pumps each having a flow of approximately 50 1/min. and a pressure of approximately 120 bar.
• An outlet line 12 leads to a plurality of fire zones A-E having respect ⁇ ive spray heads or sprinklers 13A-13E.
• the compressed gas at an ini- tial pressure of 200 bar for instance, first forcibly drives out the liquid from the tanks 15 to the respect ⁇ ive activated fire zone with a flow of for example 1000 1/min. , whereafter the operation is in principle sim ⁇ ilar as in Figure 1.
• the pressure in the compressed-gas bottles 14 has decreased to 120 bar, that is, to the pressure of the pump 11. Thereafter the pressure of the pump 11 adjusts itself in accordance with the pressure of the compressed-gas bottles 14, so that the pump flow is 20-100% of the declining total flow of extinguishing fluid.
• the pump flow is 100% of the total flow of extinguish ⁇ ing fluid.
• a container for foam concentrate is denoted at
• a freshwater tank for example 3000 litres, is denoted at 18 and a sea- water or lake-water connection is denoted at 19.
• Valve 20 In the first stage, when the tanks 15 are being emptied of liquid, the effect/action of the pump aggregate 11 is negligible. Valve 20 must be open dur ⁇ ing said first stage so that no water will enter the foam-mixing device 17 in order to keep said device out of operation, since mixing of foam into the extin- guishing fluid must be avoided at the beginning of the extinguishing operation. This is because the foam has a negative effect of making the droplets issuing from the nozzles larger, which will prevent the development of finely divided liquid mist. At the beginning of the extinguishing operation, finely divided liquid mist is specifically wanted. Thus foam will not serve well at the beginning of the extinguishing operation.
• valve 20 can advantageously be shut to supply foam into the extinguishing fluid to produce a thick "foam matting" that will prevent re-ignition. It is to be noted that the installation in accordance with Fig ⁇ ure 2 need not comprise a foam-mixing device at all. In practice, valve 20 is shut in such a way that a pres- sure switch 140 coupled in line 130 is adapted to give a pressure signal after the pressure has decreased under a predetermined level, for example 30 bar. This pressure signal thus controls valve 20.
• the gas bottles 14 can naturally be altern- atively connected to the outlet line 12 to by-pass the liquid tanks 15.

Landscapes

• Health & Medical Sciences (AREA)
• Public Health (AREA)
• Business, Economics & Management (AREA)
• Emergency Management (AREA)
• Fire-Extinguishing By Fire Departments, And Fire-Extinguishing Equipment And Control Thereof (AREA)
• Nozzles (AREA)
• Filling Or Discharging Of Gas Storage Vessels (AREA)
• Catching Or Destruction (AREA)

Priority Applications (10)

Applications Claiming Priority (4)

Publications (1)

Family

ID=26159716

Family Applications (1)

Country Status (14)

Cited By (5)

Families Citing this family (34)

Citations (4)

Family Cites Families (10)

• 1994
  • 1994-04-28 FI FI941975A patent/FI98494C/fi active
• 1995
  • 1995-04-13 DK DK02075417T patent/DK1213039T3/da active
  • 1995-04-13 RU RU96120218A patent/RU2136339C1/ru active
  • 1995-04-13 DK DK95915905T patent/DK0755287T3/da active
  • 1995-04-13 WO PCT/FI1995/000216 patent/WO1995028205A1/en active IP Right Grant
  • 1995-04-13 JP JP52674995A patent/JP3639305B2/ja not_active Expired - Fee Related
  • 1995-04-13 DE DE69533679T patent/DE69533679T2/de not_active Expired - Fee Related
  • 1995-04-13 ES ES95915905T patent/ES2183871T3/es not_active Expired - Lifetime
  • 1995-04-13 AU AU22601/95A patent/AU684018B2/en not_active Ceased
  • 1995-04-13 DE DE69527780T patent/DE69527780T2/de not_active Expired - Fee Related
  • 1995-04-13 CN CNB2004100770192A patent/CN100525863C/zh not_active Expired - Fee Related
  • 1995-04-13 EP EP95915905A patent/EP0755287B1/en not_active Expired - Lifetime
  • 1995-04-13 ES ES02075417T patent/ES2229050T3/es not_active Expired - Lifetime
  • 1995-04-13 CA CA002184572A patent/CA2184572C/en not_active Expired - Fee Related
  • 1995-04-13 US US08/716,165 patent/US5799735A/en not_active Expired - Fee Related
  • 1995-04-13 EP EP02075417A patent/EP1213039B1/en not_active Expired - Lifetime
  • 1995-04-13 CN CN95192516A patent/CN1145591A/zh active Pending
  • 1995-04-13 KR KR1019960705699A patent/KR100353178B1/ko not_active IP Right Cessation
• 1996
  • 1996-10-14 NO NO19964356A patent/NO313316B1/no not_active IP Right Cessation

Patent Citations (4)

Non-Patent Citations (2)

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