Field of the invention
[0001] The present invention relates to a flush-mounted fire extinguisher assembly.
[0002] In particular, the invention relates to an assembly for at least one flush-mounted
fire extinguisher which is arranged in a fixed position on walls, double walls, ceilings
or false ceilings and the like.
Prior art
[0003] Aerosol fire extinguishers according to the present invention are understood as meaning
fire extinguishers of the type which use a solid substance, preferably based on potassium
salts or similar mixtures which are activated by means of ignition, thus generating
the extinguishing mixture. By way of example, the solid substance may be formed by
potassium nitrate in amount equivalent to 90% and its aerosol conversion temperature
is in the region of 150°C. Moreover, the nitrate formed exothermally is completely
anhydrous and may therefore be used to extinguish a fire when it breaks out, even
in the presence of electrical equipment, without the risk of conduction caused by
electrolytic phenomena associated with the potassium salt.
[0004] These types of fire extinguishers have a hollow body which comprises internally,
communicating with the outside via openings, a chamber for receiving a solid substance
which, activated by means of an igniter, also called an activator, provided inside
the solid substance itself, is converted, at a given temperature, into an aerosol
having flame-extinguishing properties and is discharged as an aerosol through the
openings in said hollow body.
[0005] Preferably the solid substance is completely surrounded by inert material, such as
stones, alumina beads or ceramic materials. The function of the inert material is
to absorb the heat generated at the time of ignition or activation of the solid substance.
[0006] Once activated, the solid substance is converted into an aerosol formed mainly by
carbonates which enter into the flame generating chain, extinguishing it, and by other
products arising from conversion of the solid substance which produces the aerosol
and expelled together with the aerosol. These products may be carbonaceous, sticky,
oily and clingy residues in the form of large-size particles which by their nature
not only do not help extinguish the flame, but on the contrary impede the extinguishing
effect, since they are incandescent and, being conveyed along by the cloud of gas
and aerosol, could come into contact with persons present within the radius of action
of the device, burning them.
[0007] Fire extinguishers of this type are usually positioned externally on walls, ceilings
or the like, resulting in disadvantages from the point of view of aesthetics and space
occupied as well as maintenance difficulties, in particular when mounted in restricted
and/or small-size spaces.
[0008] Therefore, the main object of the present invention is to improve both the flame-extinguishing
capacity and the level of safety during use of a flush-mounted aerosol fire extinguishing
device, with regard to the danger posed by incandescent particles emitted from it.
[0009] According to the present invention, an assembly for a flush-mounted aerosol fire-extinguishing
device which overcomes the abovementioned drawbacks is provided, said assembly comprising
a box-shaped body, which preferably has a substantially parallelepiped form and is
able to be flush-mounted and positioned in a fixed location in walls, double walls,
ceilings and false ceilings and the like, the side thereof which faces the room being
closed by means of a panel formed substantially by a so-called labyrinth grille which
performs a further filter function.
[0010] The box-shaped body, which is kept in position by a shaped seat, in a manner known
per se, fixed to the box-shaped body, contains at least one aerosol fire extinguisher
consisting preferably of a cylindrical body with holes on its outer surface of the
conventional type and containing a cylindrical package of solid substance, heating
of which is performed by means of an activator in the form, for example, of an igniter
which is preferably situated inside the cylindrical package of solid substance convertible
into aerosol.
[0011] The present invention will now be described with reference to a preferred embodiment
thereof, although it is understood that constructional variations are possible without
thereby departing from the scope of protection of the present invention and with reference
to the figures of the accompanying drawings in which:
Figure 1 shows a top plan view, partly cut away, of the flush-mounted fire extinguisher
assembly according to the present invention;
Figure 2 shows a cross-section along the line A-A of Figure 1;
Figure 3 shows a perspective top plan view of the casing of the flush-mounted fire
extinguisher assembly;
Figures 4 and 4a show a perspective and partly sectioned view of the flush-mounted
fire extinguisher assembly and an example of a labyrinth profile; and
Figure 5 shows a schematic view of the flush-mounted fire extinguisher assembly in
combination with a preferred embodiment of the associated connections to replaceable
igniters.
[0012] With reference to the drawings, Figure 1 shows a top plan view, partly cut away,
of the flush-mounted fire extinguisher assembly, comprising a box-shaped element 1
housing internally at least one aerosol extinguisher 2 formed by a hollow body with
a preferably cylindrical shape and comprising at least one cable guide 3 with connector
4 emerging from the box-shaped body 1.
[0013] With reference to Figure 2 the box-shaped body 1 has at least one semi-cylindrical
seat integral with the end grille 6 of the box-shaped body 1 for holding at least
one extinguishing device 2.
[0014] Figures 3 and 4 show a perspective bottom and side view, respectively, of the box-shaped
body 1. Said box-shaped body 1 is fastened to a labyrinth grille 6 by means of the
flange 6a.
[0015] With reference to Figure 4, this shows the layout of the end grille 6 of the labyrinth
type, suitable for retaining carbonaceous, sticky, oily and clingy residues in the
form of large-size particles.
[0016] Figure 4a shows a partial cross-section of an example of the form of a grille 6 of
the labyrinth type with filter functions, consisting of a flanged frame 6a which supports
a filtering partition formed by shaped blades 60, 61 which, in a preferred embodiment,
are curved and made of the same material as the frame. This characteristic form forces
the outflowing air to change direction suddenly such that the solid particles, owing
to the inertia resulting from them by their mass, strike the walls of the shaped blades,
which capture these particles, separating them from the outgoing air flow.
[0017] Figure 5 shows schematically an alternative embodiment of the electrical connection
and the various connections, externally, of the at least one fire extinguishing device
2.
[0018] As is known, heating of the cylindrical package of solid substance contained in the
extinguishing device 2 is performed by means of an activator in the form of an igniter
10 situated, for example, inside the cylindrical package of solid substance convertible
into aerosol. Such an igniter device is preferably of the extractable type for easier
maintenance without the need for disassembly of the at least one extinguishing device
2 in its entirety. For this purpose a fire extinguisher 2 of the conventional aerosol
type has, inserted therein, a guided and separately removable igniter 10.
[0019] This igniter 10 is connected externally to the grille 6 via a first cable-guide holder
and/or male connector 11, which is in turn placed in electrical contact with a connector
12 which is electrically connected via a bipolar cable 12a to an intermediate male
connector 13 connected to a further female connector component 14 which leads to the
central control unit. If the box-shaped body has a second extinguishing device 2',
with an extractable igniter, the connection to the connectors 13 e 14 is repeated
symmetrically via the contact holder 11, which is interconnected with a second extractable
igniter of said second aerosol extinguisher device 2'.
[0020] According to this embodiment, in order to perform maintenance of the igniter 10 it
is possible to disconnect the connector components 12, 13 and 14, then remove the
internal cylindrical guide integral with the igniter from the outer cylindrical guide
which remains inserted, fixed in the at least one extinguishing device, and replace
the igniter, without removing the at least one extinguisher 2, 2' from the fixed position
inside the box-shaped casing 1.
[0021] During operation, the solid aerosol substance inside the cylindrical package contained
in the extinguisher 2 is heated to the appropriate temperature by the activator, is
converted into aerosol and the aerosol is discharged through the holes 7 in the casing
of the extinguisher 2. The suspended granules of the product converted into aerosol
have a maximum diameter of 4 microns. In the vicinity of the flame, the aerosol interferes
chemically with the combustion reaction chain, removing the free radicals (OH), which
are thus no longer available for fuelling the combustion, and physically drawing energy
from the combustion environment. Since the two actions occur on the surface of the
solid aerosol particles, the smaller the size of the particles, the greater will be
the reaction area available and the more effective will be the extinguishing action.
[0022] In order to prevent incandescent particles bigger in size than those which normally
form the aerosol from escaping, a grille of the labyrinth type 6, for example such
as those used for suction hoods, is provided, removably fastened to the box-shaped
casing 1. This grille 6 not only does not hinder the expulsion of the extinguishing
powder, but on the contrary increases it and favours operation since the spiral or
labyrinth grille, during expansion of the powder, retains the particulate formed by
carbonaceous, sticky, oily and clingy residues in the form of large-size particles.
During the extinguishing process, these particles which are incandescent and conveyed
by the cloud of gas and aerosol may come into contact with persons present within
the radius of action of the device and by their nature do not help extinguish the
flame.
[0023] Persons skilled in the art will understand that a flush-mounted fire extinguisher
assembly as described above may be applied to an aerosol fire extinguishing device
operating not with an activator or igniter, but with other means for raising the temperature
of the solid substance up to its aerosol conversion temperature.
[0024] With an arrangement of the flush-mounted fire extinguisher assembly according to
the present invention, both aesthetic and functional advantages are achieved. Aesthetic
advantages in particular are obtained for example in the case where the entire assembly
is flush-mounted inside ceilings, false ceilings, walls or the like, since only its
labyrinth or spiral grille surface 6 is visible. Functional advantages are achieved
for example from the point of view of the space occupied or obstructions, in particular
in the case of service rooms and data processing centres where the spaces are limited
and any protrusion may be a hindrance. Moreover, the arrangement according to the
present invention results in easier and less costly assembly and maintenance compared
to the known arrangements; in fact, with the arrangement comprising at least one extinguishing
device which can be combined with a further extinguishing device, it is possible to
use smaller size extinguishers for the same effective surface area covered, with easy
installation, assembly and maintenance, this not being possible with the known arrangements.
[0025] The embodiment described and illustrated is shown purely by way of example, although
it is understood that numerous constructional variations may be made without thereby
departing from the scope of protection of the present invention.
1. Flush-mounted fire extinguisher assembly, characterized in that it comprises a box-shaped body (1) suitable for being flush-mounted in walls, double
walls, ceilings, false ceilings and the like, the side thereof which faces the room
being closed by a covering panel (6) formed by a labyrinth grille with a filter function,
the box-shaped body (1) containing internally at least one aerosol extinguishing device
(2, 2').
2. Flush-mounted fire extinguisher assembly according to Claim 1, characterized in that the at least one extinguisher (2) inside the box-shaped body (1) is kept in position
by a shaped seat (5) removably fastened to the said box-shaped body (1).
3. Flush-mounted fire extinguisher assembly according to Claim 1, characterized in that the at least one extinguisher (2) is formed preferably by a cylindrical body with
holes on its outer surface, housing internally a cylindrical package of solid substance
convertible into aerosol.
4. Flush-mounted fire extinguisher assembly according to any one of the preceding claims,
characterized in that the labyrinth grille (6) comprises shaped blades (60, 61) able to prevent incandescent
and dangerous particles of solid substance from being emitted into the room.
5. Flush-mounted fire extinguisher assembly according to any one of the preceding claims,
characterized in that an activator which can be activated externally is located inside the solid substance
for ignition thereof.
6. Flush-mounted fire extinguisher assembly according to any one of the preceding claims,
characterized in that a guided and separately removable igniter (10) is inserted inside the at least one
conventional aerosol extinguishing device (2) as an activator.
7. Flush-mounted fire extinguisher assembly according to any one of the preceding claims,
characterized in that, in each of the at least one extinguisher (2), the guided and removable igniter (10)
is connected externally to the grille (6) via a first cable-guide and/or male connector
(11) in turn placed in electrical contact with a connector (12) which is electrically
connected via a bipolar cable (12a) to an intermediate male connector (13) connected
to a further female connector component (14) which leads to the control unit.
8. Use of grille filters (6) of the labyrinth type for capturing carbonaceous, sticky
and/or oily residues in the form of particles expelled from aerosol extinguishers
and produced during operation of said extinguishers.