Note: Descriptions are shown in the official language in which they were submitted.
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TITLE OF THE INVENTION
I~IPROVEMENTS IN AND RELATING TO FIRE EXTINGUISHERS
BACKGROUND OF TIIE INVENIION
In fire suppression systems requiring a high mass flow rate of
extinguishant, for example in order to quench an incipient fire in the pre-
sence of a highly volatile liquid fuel, it is known to achieve the required
rapid discharge of extinguishant from a container, by opening a relatively
large bursting diaphragm fitted to a venting port of the container, thus
permitting the contents to be ejected either by the vapour pressure of the
extinguishant, or by the pressure derived from other means, for example an
additional gas filling. Burstable containers of this kind have been proposed
for use, for example, in aircraft fire suppression systems. However, such
burstable containers have the disadvantage that the high mass flow rate of
the fire extinguishant discharged therefrom can cause unduly high reaction
forces to be imposed upon the container and thus upon the mountings by which
` it is secured in, for example, an aircraft, which reaction forces may possibly
lead to failure of the mountings and damage to the adjacent structure of the
aircraft.
SUMMARY OF T~E INYENTION
:
It is an object of the present invention to eliminate, or at least
to reduce, the above-mentioned disadvantage of the known fire extinguishers
referred to.
` The present invention provides a fire extinguisher comprising a
`- container providing a source of extinguishant, a burstable diaphragm defining
a part of said container and permitting, upon bursting thereof, a high mass
flow rate of extinguishant from the container, wall means arranged in spaced,
facing relationship to said diaphragm and being at least substantially equal
in area to said diaphragm whereby said wall means provides an impingement
surface for a jet of extinguishant released upon bursting of said diaphragm,
; 30 and means locating said wall means in fixed relation to said container whereby
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the reaction force upon said container due to the discharge of the jet of
extinguishant therefrom is substantially balanced by the reaction force on
said wall means, due to the impingement of the jet extinguishant thereon,
the said locating means defining lateral outlet ports between said diaphragm
and said impingement surface, said outlet ports occupying the major part of
the peripheral space between said diaphragm and said impingement surface to
permit substantially unimpeded dispersal of extinguishant deflected by said
impingement surface, and the number, size and position of the said discharge
ports being balanced in such a manner that the reaction forces upon said
container due to the flow of extinguishant from the discharge ports substan-
tially balance one another.
BRIEF DESCRIPTION OF THE DRA~INGS
The invention is illustrated by way of example in
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thc accompal~ing dra~ings, in whic:h:
Figure 1 is a side elevation of a fire extinguisher
in accordance wi-th one embodiment of -the present lnven-
tion,
Figure 2 is a view in the direc-tion of the arrow
A of Figure 1,
Figure 3 is a view s:imilar to.~igure 1 of a fur-ther
~ embodiment of extinguisher in accordanoe with -the inven-~ tion, and
:: 10 Figure 4 ls a view in the direc-tion of the arrow
.~ B of Figure 3.
` ~ DESCRIPTION OF T:~IE PRE ERRE:D EMBODIMENT
.` Referring to Figures 1 and 2 of -the drawings, a~ fire extinguisher in accordance with one embodiment of
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- 15 the invention comprises a hollow bulb 1 defining a con~
tainer for fire extinguishant. Attaohed to the bulb 1
are a lu~ion 2, providing-for connectlon of the.extin~
guisher into an electrical control circuit of kno~m type
. not further illus-trated, and a flange extlnguishant
~ 20 discharge port 3 closed, in known manner, by means of~
: ~ . a burstabIe diaphragm (not shown). r~he internal con~struction of the ex-tinguisher is of generally known :
type, and -therefore not illustrated or referred -to :
in more detail. Briefly, however, upon receipt of an
appropriate con-trol signal via the union 2, the dia-
phragm closing -the discharge port 3 is ruptured~ for
example by means o~ an explosive charge located within
the bulb 1, to release the contents of the extinguisher.
r~he discharge port ~ is provided with an end cap
4, having lateral discharge orifices 5 for extinguishantO
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~hus in accordance ~ith the inven-tion~ the end cap 4
provides for deI`lection of the fire extinguishant -through
the ori~ices 50 The discharge orifices 5 are regularly
spaced aro~md the periphery o~ the end cap 4, and thus
a ~60 radial dispersal o~ extinguisharlt is achieved,
with substantially zero resul-tant -reaction force being
imposed upon the body of the extinguisher.
~he end cap defines a wall means 7 which is dis- ;
posed in spaced, facing relationship ~Lth the diaphragm
-~ 10 closing port 3 and, as can be seen in -the drawing, the
wall means is at least of equal area to said diaphragm.
~ ~ The wall means defines an impingement surface 8- ~`gainst
`~ which the extingulshant, exiting the container, strikes,
` - thus generating a substantially equal and opposite force
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to that generated by the extinguishant on the container
as it exits that container.
- ~ Although the discharge orifices 5 of the end cap
`-` 4 are as illus-trated in Figures ~ and 2 of such relative
proportions that a subs-tantially radial 360 dls-tri~
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bu-tion of discharged extinguishant is obtained, i-t will~
be appreciated that by adjusting the arrangement and
relative dimensions of the discharge orifice 5, the
distribution pattern of the extinguishant can be modi-
fied in any desired manner. For example, by increasing~
the axial length of the orifices 5, a greater dispersion
of extinguishan-t in the axial direction of -the end cap
4 can be achieved. Also~ as illustrated in Figures
and 4, auxiliary baffles 6 may be provided for deflec-
tion of the extin~lishan-t in an axial direction.
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