Classifications

• • 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
• • A—HUMAN NECESSITIES
  • A62—LIFE-SAVING; FIRE-FIGHTING
  • A62C—FIRE-FIGHTING
  • A62C31/00—Delivery of fire-extinguishing material
  • A62C31/02—Nozzles specially adapted for fire-extinguishing
  • A62C31/12—Nozzles specially adapted for fire-extinguishing for delivering foam or atomised foam

Definitions

• the present invention relates to fire protection installations. It relates, more particularly, to an extinguishing system by sprinkling the fire using foam which is particularly well suited to fighting fires in large enclosed spaces, such as tunnels, parking lots or warehouses.
• Such an installation must, first of all, be equipped with detectors: - with rapid response, that is to say reacting instantaneously to an abnormal rise in temperature, and - reliable, that is to say as little sensitive as possible to changes in temperature (frost, etc.) but also to dust or other soiling which may partially or completely "blind” them.
• a fire-fighting installation in a large space must also be able to respond, in a targeted manner, to several fires separated from each other, which is frequent in a voluntary fire or when, in a tunnel, a first fire causes chain collisions and new fires. It is therefore vital that the installation intervenes at this location and is not prematurely in the process of extinction because it too quickly exhausted its resources on the first fire.
• This installation comprises a plurality of distinct assemblies each assigned to the protection of a sector of the tunnel and comprising, for each sector: - a plurality of thermal detectors each closing the end of a conduit supplied with compressed air and reacting to a abnormal rise in ambient temperature by opening said duct in the open air, - a foam extinguishing system taking place above the sector to be protected, and - control means which respond to a pressure drop resulting from venting at least one of said conduits by supplying said system with a mixture of pressurized water and foam concentrate allowing it to pour extinguishing foam onto this sector.
• the main object of the present invention is to provide an improved version of a foam extinguishing system which can equip not only the above-mentioned installation, but also any existing installation, whether automatic or manual.
• the invention relates to a fire extinguisher system using foam, which comprises: - a tube intended to take place above the space to be protected and which can be supplied from the using a mixture of pressurized water and foam concentrate, and - at least one extinguishing nozzle comprising at least one slit made in the wall of said tube and a swelling cage arranged to receive the jet of liquid delivered through said slit and produce foam which is poured onto said space.
• This extinguishing system also has the following main characteristics: -
• the slot is substantially parallel to the axis of the tube and to the axis of the cage.
• the nozzle has several parallel slots.
• the cage is made of mesh and has an upper wall with a triangle-shaped section, the edge of which faces the slot, parallel to it, and a curved lower wall substantially concentric with the tube.
• the angle at the top of the triangle is substantially between 110 and 130 °.
• the base of said triangle has substantially the same dimension as the diameter of the tube.
• the base of the lower part of the cage has substantially the same dimension as that of the triangle.
• the cage has an intermediate wall between its upper wall and its lower wall.
• This intermediate wall is extended, beyond its junction with the upper wall, by a portion which ends substantially at the edge thereof.
• the slot has a width between 0.3 and 1 mm and the edge of the top of the triangle of the cage is arranged about 1 mm from it.
• the cage is secured to a collar taking place around the tube.
• the system includes a plurality of nozzles arranged on the tube so as to distribute the watering throughout the space to be protected.
• FIG. 1 is a schematic representation of an installation according to the invention
• - Figures 2 and 3 are views in longitudinal and cross section of a foam nozzle fitted to this installation
• - Figure 4 illustrates how to fix the cages of the extinguishing nozzles to the tube.
• FIG. 1 very schematically represents, seen from the ground, a portion of the roof of a road tunnel equipped with an installation using a foam extinguishing system according to the invention.
• the installation proposed by way of nonlimiting example is divided into sectors of approximately twenty to thirty meters, each comprising a sprinkler tube 10 disposed under the roof of the tunnel, parallel to the axis AA of the sector concerned, and provided with foam extinguisher nozzles 12 arranged, approximately every three meters. These nozzles are directed towards the ground and, in the example shown, aligned along the axis AA.
• the installation also includes a mixer 14, the inlet E1 of which is connected to a single pressurized water pipe 16 passing through the tunnel and the inlet of which E2 is connected to a foam concentrate tank 18 via a regulating valve 20.
• the outlet S of the mixer 14 is connected to the sprinkler tube 10 via a control valve 22.
• FIGS. 2 and 3 show, more precisely, the sprinkler tube 10 and the foam extinguishing nozzles 12 according to the invention.
• the tube 10 is of circular section. Its diameter is typically between 25 and 150 mm and its length is that of the sector, that is to say from twenty to thirty meters in the example described.
• the nozzles 12 each consist of a slot 24 formed in the wall of the tube 10 vertical to its axis AA and parallel to it and of a device 26, called a foam expansion cage, disposed in front of the slot.
• a device 26 called a foam expansion cage, disposed in front of the slot.
• the length thereof is between 60 and 100 mm and its width is approximately 0.2 to 1 mm depending on the water supply and the flow rate of foam necessary for extinction.
• the expansion cage 26 is formed by an upper wall 28, a lower wall 30 and an intermediate wall 32, produced by means of a mesh of stainless steel or synthetic material whose mesh is between 1 and 3 mm.
• the upper wall 28 has a triangle-shaped section, the edge of which faces the slot 24 parallel to it and is arranged about 1 mm from it.
• the angle at the top of the triangle is between 110 and 130 °, while its base has substantially the same dimension as the diameter of the tube 10.
• the lower wall 30 is curved, with a center substantially coincident with that of the tube 10. Its base has the same dimension as that of the upper wall 28.
• the intermediate wall 32 planar, provides the connection between the upper wall 28 and the lower wall 30. It will be noted that it extends, beyond its junction with the upper wall 28, by a portion 34 which ends at the level of the edge thereof. The distance between the edge and the point furthest from the bottom wall 30 is typically between 30 and 50 mm.
• the walls of the cage 26 are advantageously joined by welding or by stapling.
• the edge of the upper wall 28 is extended, at its two ends, by a tongue 36 which is welded to a collar 38 taking place around the tube and hanging on it using a loop 40 and a hook 42.
• control valve 22 In operation, when a fire is detected by any means, the control valve 22 is opened manually or automatically. A mixture of water and foam concentrate, the content of which, typically from 2 to 5%, has been previously adjusted by the regulating valve 20, is sent to the sprinkler tube 10.
• the slot 24 creates a powerful jet directed on the edge of the upper wall 28. This jet penetrates into the cage 26 and invades it while generating a suction current which brings in air mixing intimately with the particles of liquid.
• the mixture then passes through the intermediate wall 32 and the bottom wall 30 with a pressure still sufficient to confine the emulsion and produce a dense foam heavy enough to cover the floor of the tunnel without being dragged by drafts.
• the projected jet of water and foam concentrate is sufficiently deflected so that foam is also produced above the cage 26 and passes through the upper portion 34 of the intermediate wall 32, thus adding to the foam. ejected from the cage.
• the cage 26 also has the effect of diverting the jet of foam by 90 °. It is likely that this deviation is due to Coriolis forces.
• the foam forms a screen whose plane is substantially perpendicular to the longitudinal axis of the tunnel and which folds down and absorbs the smoke from the fire.
• the objective of this installation is to produce a thickness of 15 cm of foam per minute and per square meter, distributed uniformly over the roadway of the tunnel. This thickness is sufficient to extinguish most fires.
• a single nozzle, dimensioned as described above, produces: 26.2 x 3 1/2 x 30 1.351 m 3 / min of foam.
• the water flow rate must therefore be 1034 L / min.
• the installation can comprise two or three parallel tubes distributed under the roof.
• each nozzle may include a plurality of slots centered on the edge of the top of the triangle of the cage, for example, three 0.2 mm slots separated by 2 mm.

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)
• Fire-Extinguishing Compositions (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=34585931

Family Applications (1)

Country Status (6)

Families Citing this family (1)

Citations (4)

• 2003
  • 2003-12-17 SI SI200331734T patent/SI1552860T1/sl unknown
  • 2003-12-17 DE DE60330170T patent/DE60330170D1/de not_active Expired - Lifetime
  • 2003-12-17 ES ES03405902T patent/ES2335982T3/es not_active Expired - Lifetime
  • 2003-12-17 AT AT03405902T patent/ATE448837T1/de active
  • 2003-12-17 EP EP03405902A patent/EP1552860B1/fr not_active Expired - Lifetime
• 2004
  • 2004-12-09 WO PCT/CH2004/000725 patent/WO2005058424A1/fr active Application Filing

Patent Citations (4)

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