DELIVERY OF FIRE-EXTINGUISHING MATERIAL BY A PRESSURE GAS SOURCE

APPLICATION D'AGENT EXTINCTEUR PAR SOURCE DE GAZ SOUS PRESSION

English Abstract

The invention relates to a fire-fighting
equipment, comprising a hydraulic
accumulator (H) and a pressure gas source (T)
connected thereto for driving liquid by means of
pressure gas out of the hydraulic accumulator
through an outgoing liquid tube (6) arranged
in the accumulator. The object of the
invention is to provide a novel equipment
permitting an efficient liquid delivery from one
hydraulic accumulator (H) or a plurality of
hydraulic accumulators (H, H'), by mixing gas
efficiently in the liquid immediately from the
beginning. This is achieved in such a way
that the outgoing liquid tube (6) comprises a
throttling (11) and that to the liquid tube (6),
after said throttling (11), is connected a
throttled gas inlet (13) preferably from the same
pressure gas source that is connected to the
hydraulic accumulator (H) for driving liquid
out of this accumulator.

French Abstract

Equipement de lutte contre l'incendie comportant un accumulateur hydraulique (H) et une source de gaz sous pression (T) reliée à celui-ci de manière à ce qu'un liquide contenu dans l'accumulateur hydraulique soit entraîné vers l'extérieur par le gaz sous pression en passant par une conduite de sortie de liquide (6) logée dans l'accumulateur. Cette invention a pour objet d'offrir un nouvel équipement permettant de libérer un liquide de manière efficace à partir d'un accumulateur hydraulique (H) ou d'une série de tels accumulateurs (H, H'), en mélangeant dès le départ le gaz dans le liquide de manière efficace. Ce résultat est obtenu par le fait que la conduite de sortie du liquide (6) comporte un étranglement (11) et que cette conduite (6), après ledit étranglement (11), est reliée à une admission de gaz régulée (13) de préférence depuis la même source de gaz sous pression qui est reliée à l'accumulateur hydraulique (H) pour extraire le liquide de cet accumulateur.

Claims

6
CLAIMS:
1. A fire-fighting equipment, comprising a
hydraulic accumulator with a liquid container and a
pressure gas source, a connection being provided for
connecting the pressure gas source to the hydraulic
accumulator, said pressure gas source being adapted to
drive liquid by means of pressure gas out of the
hydraulic accumulator through an outgoing liquid tube
arranged in the accumulator, a throttle means being
provided between the pressure gas source and the
outgoing liquid tube, characterized by a check valve
connected between the pressure gas source and the
liquid container preventing back flow of gas from the
liquid container to the throttle means.
2. An equipment according to claim 1,
characterized in that the throttle means comprises a
gas inlet formed after a throttling made in the
outgoing liquid tube.
3. An equipment according to claim 2,
characterized in that the throttling of the outgoing
liquid tube and the gas inlet are adapted to provide
essentially equal pressure drops.
4. An equipment according to claim 2, wherein
the connection comprises a housing with a gas inlet to
the accumulator, the outgoing liquid tube and a
mounting part to be mounted in the outlet of the
hydraulic accumulator, characterized in that the
throttling of the outgoing liquid tube extends through
the mounting part of the housing and that the gas inlet
after the throttling of the liquid tube is constituted
by at least one aperture in the wall of the liquid

7
tube, which aperture is in contact with the gas inlet
of the connection to the hydraulic accumulator.
5. An equipment according to claim 4,
characterized in that the throttling of the liquid tube
extends past the mounting part into the liquid
container of the hydraulic accumulator.
6. An equipment according to claim 5,
characterized in that the check valve comprises a ring
element positioned around the liquid tube and loaded by
a spring.
7. An equipment according to claim 4,
characterized in that a gas outlet to the gas inlet of
an adjacent accumulator connection is arranged within
the extent of the throttling of the liquid tube.
8. A fire-fighting equipment comprising:
a hydraulic accumulator with a liquid container,
the liquid container having a gas space;
a pressure gas source;
a connection connecting the pressure gas source to
the hydraulic accumulator for feeding pressure gas to
the liquid container through a gas inlet thereof and
driving liquid by the pressure gas out of the hydraulic
accumulator through a rising tube having a wall in the
accumulator to an outgoing tube;
a throttle means in contact with the gas inlet and
between the pressure gas source and the outgoing tube
for mixing the pressure gas and the liquid in the
outgoing tube; and

8
a check valve connected between the gas inlet and
the gas space of the liquid container for preventing
backflow of the pressure gas from the liquid container
to the throttle means.

Description

CA 02184895 2005-O1-31
1
DELIVERY OF FIRE-EXTINGUISHING MATERIAL BY A PRESSURE GAS SOURCE
The present invention relates to a fire-fight-
ing equipment, comprising a hydraulic accumulator and
' 5 a pressure gas source connected thereto for driving
liquid by means of pressure gas out of the hydraulic
accumulator through an outgoing liquid tube arranged in
the accumulator.
Certain kinds of petrol fires,~e.g. a kerosene
fire in a jet engine of an aeroplane during engine test
in a hangar intended for that purpose, are almost impos
sible to extinguish, even by means of strong fog-like
liquid sprays, as is proposed e.g.
in CA 2,103,069. Such a jet engine
fire is not extinguished until the whole hangar in ques
tion, which may typically have a volume of about 3000
cubic metres, has been subjected: to so-called "total
flooding", which means that it has been filled with a
liquid fog consisting of very small drops practically
entirely.
The liquid fog required can be generated in
principle by means of an equipment
described in CA 2,123,706. In said
application, an outgoing rising pipe of a hydraulic ac-
_ cumulator is provided with apertures in its wall so that
the drive gas of the accumulator initially drives out
liquid only and the drive gas is being mixed into the
outgoing liquid gradually after the liquid level has
fallen to the level of the uppermost aperture in the
tube wall, in increasing proportions according to the
falling liquid level and more apertures in the tube wall
becoming free. During final discharge stage of the accu-
mulator, a liquid fog consisting of drops small enough
for the present purpose can be achieved, but a far too

CA 02184895 2005-O1-31
2
large part of the liquid of the hydraulic accumulator
is lost.
The gas source may be a container including
nitrogen gas and having a charge pressure of e.g. about
200 bar, and it can be arranged to feed one hydraulic
accumulator or a plurality of hydraulic accumulators
connected in parallel.
The object of the invention is to provide a
novel equipment enabling an efficient liquid delivery
from one hydraulic accumulator or a plurality of
hydraulic accumulators by mixing gas efficiently in the
liquid immediately from the beginning.
In one embodiment there is provided a fire
fighting equipment, comprising a hydraulic accumulator
with a liquid container and a pressure gas source, a
connection being provided for connecting the pressure
gas source to the hydraulic accumulator, said pressure
gas source being adapted to drive liquid by means of
pressure gas out of the hydraulic accumulator through
an outgoing liquid tube arranged in the accumulator, a
throttle means being provided between the pressure gas
source and the outgoing liquid tube, characterized by a
check valve connected between the pressure gas source
and the liquid container preventing back flow of gas
from the liquid container to the throttle means.
The equipment according to the invention is
mainly characterized in that the outgoing liquid tube
comprises a throttling and that to the liquid tube,
after said throttling, is connected a throttled gas
inlet from a pressure gas source having a pressure

CA 02184895 2005-O1-31
2a
higher than the liquid pressure after the throttling of
the outgoing liquid tube.
In a preferred embodiment of the invention,
the pressure gas source connected to the throttled gas
inlet is the same that is connected to the hydraulic
accumulator for driving liquid out of this accumulator.
The throttling of the outgoing liquid tube
and the throttled gas inlet are hereby preferably
adapted to provide at least essentially equal pressure
drops. If the gas source has a pressure of 100 bar,
the respective throttlings can be dimensioned to
provide a pressure drop of e.g. 5 bar.
If the pressure gas source is constituted by
a pressure bottle, this can be connected to the
hydraulic accumulator through a check valve loaded
against the gas pressure, which valve shuts off the gas
supply at a predeterminable pressure. Subsequently,
the gas enclosed in the accumulator continues driving
out gas

WO 95/24239 218 4 8 9 5 pCT~~S/00130
3
by expanding, while the gas source continues delivering
gas only through the throttled inlet after the throt-
tling of the liquid tube.
In a preferred embodiment, the pressure gas
source is coupled to the hydraulic accumulator through
a connection, which comprises a housing provided with
a gas inlet to the accumulator, an outgoing liquid tube
and a mounting part for mounting in the outlet of the
hydraulic accumulator, whereby the throttling of the
outgoing liquid tube extends through the mounting part
of the housing and the throttled gas inlet after the
throttling of the liquid tube is constituted by at least
one aperture in the wall of the liquid tube, which aper-
ture is in contact with the gas inlet of the connection
into the hydraulic accumulator. A ring channel between
the throttling of the liquid tube and the mounting part
surrounding the throttling offer a simple solution to
an efficient gas supply at a high pressure.
If the gas source feeds more than one hydraulic
accumulator, a gas outlet to the gas inlet of an adjac
ent accumulator connection may preferably be arranged
within the extent of the throttling of the liquid tube.
In the following, the invention will be de
scribed with reference to the attached drawing including
Figures 1, 2 and 3, showing two preferred embodiments
of the equipment according to the invention.
The embodiment shown in the Figures 1 and 2
contains a connection A, comprising a housing 1 provided
with a gas inlet 2 for being connected to a pressure gas
source T, a threaded outgoing liquid tube 3, a hold 4
for a safety plug or alternatively a gas outlet 4 (pre-
ferably of the same form as the inlet 2) to an adjacent
similar connection A' of an adjacent hydraulic accumula-
tor H' and a mounting part 5 provided with an external
thread to be mounted in the outlet of a hydraulic accu-

WO 95/24239 ~ ~ ~ ,~ 8 9 5 PCT/FI95/00130
4
mulator H. An outgoing rising tube of the hydraulic
accumulator H is indicated by 6. An outlet end 7 of the
tube 6 is connected to the outgoing tube 3 by means of
a shear ring coupling 8. A support ring is indicated by
9 and a sealing ring arranged in connection with this
is indicated by 10.
The tube 6 portion extending inside the mount-
ing part 5 of the housing 1 in front and preferably in-
cluding the gas inlet 2 as well is throttled in relation
to the rest of the diameter dimension of the tube 6 and
indicated by 11. Thanks to the throttled tube portion
11, a pressure drop is provided, as well as a ring chan-
nel 12 between the tube portion 11 and the housing 1
from the gas inlet 2 along the mounting part 5 of the
housing into a liquid container of the hydraulic accumu-
lator H.
The ring channel 12 permits an efficient supply
of drive gas to the liquid container of the hydraulic
accumulator H and through that an efficient delivery of
liquid into the outgoing tube 3.
After the throttling 11 is arranged a throttled
gas inlet 13, which may be a suitably dimensioned aper-
ture in the wall of the tube 6 and in direct contact
with the gas inlet 2, as suggested in the drawing.
The pressure drop of the outflowing liquid over
the throttling 11 is preferably equal to the gas pres-
sure drop in the throttled inlet 13, e.g. about 5 bar.
A spring-loaded F check valve B acting against
the pressure of the gas flowing through the ring channel
12 can be positioned around the liquid tube 6 before the
throttling 11, e.g. in such a way that a ring element
R strives to bear against the end of the mounting part
5.
The throttling of the tube portion 11 can be
performed conveniently e.g. by means of existing clamp-

CA 02184895 2005-O1-31
ing means fog hoses of different kind. As to the other
parts, the connection according to the invention is an
extremely simple construction.
Figure 3 shows an alternative embodiment.
5 The liquid container of the hydraulic accumula-
tor is not shown in the drawing. As to the liquid con-
tainer and other general arrangements, reference is
again made to FI 931405 equivalent to CA 2,147,379,
Figures 7 to 9.

Representative Drawing