Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02160891 2005-O1-05
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METHOD AND INSTALLATION FOR REMOVING SMOKE FROM A
MONITORED SPACE.
The present invention relates to a method and an
installation for fighting fire, in particular for
rather large units, such as hotels, passenger ships
and various public spaces, e.g. restaurants.
A problem with known sprinkler installations,
especially automatically releasable ones, is that they
usually are arranged to be released at a certain
increased temperature and therefore react too late;
smoke generation may have been going on for up to half
an hour, with devastating effects. The great majority
of victims in various fires are poisoned by smoke.
The object of the invention is to provide a new
1S method and a new installation for fighting fire,
which effectively prevent smoke from spreading.
The method according to the invention is mainly
characterized by producing, utilizing at least one
sprinkler or spray head spraying high pressure liquid
in the form of small droplets, like a fog, into an
out-going ventilation or air condition duct of said
unit, a suction from a monitored space into said out-
going ventilation or air condition duct, in order to
remove smoke gases from the monitored space.
2S More specifically, the present invention
provides a method for fighting fire or for smoke
removal in a space having a line system via which
liquid is suppliable. to at least one sprinkler or
spray head, the space also having a ventilation or
air-conditioning duct out-going therefrom in which
method high pressure liquid in the form of a fog of
small droplets is sprayed from the at least one
sprinkler or spray head into said duct to produce a
suction from said space into said duct, to remove
smoke gases from said space, comprising the steps
of: a) dividing the space into fire sections by
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dividing the line system into line system Sections
with section valves; b) upon receiving a smoke alarm
signal from a fire section, closing all of said
section valves except the section valve of the said
fire section which sent the smol~e alarm signal; and
c) signalling a drive unit for the spraying of the
high pressure liquid into said duct via the line
system section of the said fire section.
The present invention also :provides installation
for fighting fire in a space, comprising a shower or
toilet room, a through-wall opening into said shower
or toilet room from said space and at least one
ventilation or air-conditioning duct out-going from
said shower or toilet room, the installation
comprising: at least one spray head for spraying
liquid in the form of a fog of small droplets into
said ventilation or air-conditioning duct to produce a
suction, to draw smoke into said ventilation or air-
conditioning duct from said space; and a sprinkler in
said space arranged, upon release, to activate a
further spray head in said opening to produce a
suction from said space past said further spray head,
to draw smoke into said shower or toilet room for
removal by said ventilation or ai:r-conditioning duct.
Existing ventilation and a:ir condition duct do
not in general endure heat. An essential advantage
of the invention is therefore that the suction for
drawing the smoke out is produced by means of fog-
like liquid spraying having a good cooling effect.
By a high drive pressure is here meant a
range from about 20 bar up to about 300 bar, as
compared to some 6-10 bar in conventional
sprinkler installations. The droplet size is
preferably about 50-150 microns. The sprinklers or
spray heads preferably have>. a plurality of
nozzles directed obliquely outwards and mutually
adapted in such a way that they together
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produce a suction concentrated fog-like liquid spray
with a good penetration power.
Said at least one sprinkler or spray head is
preferably activated, automatically or manually, on
the basis of smoke alarm or detection, whereat smoke
generated already at an early stage of a fire will be
removed and thus decisively prevented from spreading.
In passenger ships and hotels which usually are
divided into fire sections with electrically operated
section valves, the smoke gases tend to spread
especially along corridors. When a smoke alarm signal
is received from a fire section, the rest of the
section valves are closed, whereafter a signal is
given, e.g. after 30 seconds, to a pump unit of the
installation or to a drive unit comprising a set of
hydraulic accumulators, in order to rise the pressure,
e.g. to 100 bar, whereat suction removal f smoke is
initiated in the corridors and similar s~;~ces of the
fire section in question.
2p Those sprinklers in corridors, rooms or cabins,
or in public spaces like restaurants, which are
intended for actual fire extinguishing, are preferably
arranged at or in the smoke suction removal openings,
whereby the sprinkler release ampoules or other types
of temperature sensitive release means are relatively
quickly heated to release temperature by the smoke
flowing past. In public spaces the smoke suction is
preferably initiated at once in the whole space.
In ship cabins the cabin sprinkler is preferably
arranged to upon activation distribute liquid to a
spray head mounted in an opening in a shower room wall
of the cabin, in order to produce a suction from the
cabin space into the shower room and further out
through that ventilation duct which usually leads out
of the shower room.
The invention shall in the following be
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described in more detail with reference to the
attached drawing which, by way of example, shows a
number of preferred embodiments.
Figure 1 shows a plan drawing of a block of ship
cabins and a corridor.
Figure 2 shows a section of a cabin and of the
corridor.
Figure 3 shows a section of a corridor sprinkler.
Figure 4 shows a section of a spray head in a
wall of a shower room.
Figure 5 shows an application of the invention in
a larger space.
In figure 1 is seen eight ship cabins 1, four on
either side of a corridor 2. From the shower or toilet
room 3 of each cabin 1 leads a ventilation duct 4 to a
collecting duct 5 which runs along the corridor 2 and
in which is maintained a certain ventilation suction.
In the cabins 1, on the wall above the cabin door, is
mounted a sprinkler 6 directed into the cabin and
arranged to, upon release, or activation, distribute
liquid via a branch line 7 to a spray head 8 mounted
in a through opening in the wall 9 of the shower room
3 and directed into the shower room.
To the out-going collecting duct 5 running in the
direction of the corridor 2 are further joined a
number of pipe elements 10. In the respective opening
of these, in the corridor ceiling, is provided a
preferably double direction sprinkler means 11, a
preferable embodiment of which is shown in detail in
figure 3. A feed line for extinguishing liquid is
designated 12. Branchings 13 lead from the feed line
to the cabin sprinklers and further branchings 14 lead
from the branchings 13 to the respective corridor
sprinklers 11. Smoke detectors are preferably provided
in each cabin and along the corridor, although not
visible in figure 1 which is a part of a fire section.
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As shown in figure 2, the ventilation ducts 4
leading out of the shower rooms 3 of the cabins, as
well as the collecting duct 5 along the corridor 2,
can be mounted in a passage between a descended
ceiling 15 and a higher ceiling. The sprinkler means
11 in the corridor 2 preferably comprise one spray
head lla directed upwards into the respective pipe
element 10 and one sprinkler llb directed downwards,
both being fed in common by a branching 14, as shown
in figure 1.
The general operation of the installation shall
in the following be described with reference to
figures 1 and 2; some details shall later be described
with reference to figure 3.
When the installation is in a state of stand-by,
a liquid pressure of e.g. 16 bar can be assumed in the
line systems 12, 13, 14 of all fire ~=actions. The
suction spray heads lla directed inro the pipe
elements 10 and further into the collecting duct 5 are
arranged to be activated at a somewhat higher
pressure, e.g. 20 bar. When the fire central receives
a smoke alarm signal from one fire section, the
section valves of the rest of the fire sections are
automatically closed; only the section valve of the
alarming section remains open. After a certain delay,
e.g. 30 seconds, the fire central gives a signal to a
pump unit, or alternatively to a drive vinit including
a set of hydraulic accumulators, to increase the
liquid pressure in the line system 12, 13, 14 of the
relevant fire section to e.g. 100 bar. All corridor
spray heads lla of the fire section are then activated
and suck smoke from the corridors 2 to the collecting
duct 5, as indicated by arrows 16 in figure 2. A major
part of the liquid sprayed into the duct 5 collects on
the bottom of the duct and can be drained to the
shower rooms of the respective cabins via ducts 17.
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The cabin sprinklers 6 and the corridor
sprinklers llb intended for actual fire extinguishing
are pressure balanced and are therefore not released
by the high pressure alone at this stage. If a cabin
sprinkler 6 is released because its release ampoule 18
5 or similar has reached release temperature, the
released cabin sprinkler 6 distributes liquid via its
branching 7 to the respective spray head 8 mounted in
the shower room wall 9 of the cabin and directed into
the shower room 3. By spraying liquid into the shower
room, the spray head 8 produces a suction drawing
smoke out of the cabin 1 into the shower room 3, as
indicated by arrows 19 in figure 2, and further out
through the ducts 4 and 5. If a corridor sprinkler llb
is released in the same way because of increased
temperature, the suction of smoke is interrupted at
that particular corridor sprinkler llb but smoke is
continued to be sucked out through the other suction
points in the corridors within the fire section.
Figure 3 shows a preferred embodiment of a
corridor sprinkler. A spray head lla directed upwards
into the pipe element 10 has a number of nozzles 20
directed obliquely outwards and a central nozzle 21.
The sprinkler llb directed down into the corridor 2
has nozzles 22 directed obliquely outwards, and a
release element 23, such as a glass ampoule.
The spray head lla and the sprinkler llb have in
common an inlet chamber 24 receiving liquid from the
line 14. In stand-by state, figure 3, the pressure in
the chamber 24 is a . g . 16 bar . This pressure is not
capable of driving a spindle 25, in the spray head
lla, upwards against a spring 26 the force of which is
adapted to be overcome by a higher pressure, e.g. 20
bar. As the liquid pressure after a smoke alarm rises
to e.g. 100 bar the spindle 25 strikes up and frees
connections for liquid to the nozzles 20 and 21.
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The sprinkler llb likewise comprises a spindle 27
which forced by a spring 28 lies against the release
ampoule 23. An axial channel 29 runs from the inlet
chamber 24 through the spindle to an annular space
between the spindle 27 and the surrounding sprinkler
housing, said annular space having an end face 30
formed by the spindle and having an area equal to that
end face of the spindle at the inlet chamber 24 which
is subjected to the pressure in the chamber 24. That
pressure of the inlet chamber 24 which acts on the end
of the spindle 27 is thus balanced by the end face 30
of said annular space, so that regardless of the
magnitude of the pressure in the inlet chamber 24,
e.g. 100 bar releasing the spray head lla, the spindle
27 is forced against the release element 23 by the
force of the spring 28 only. The release element 23
withstands this force at normal temperature. When the
release element melts or breaks at an increased
temperature the spring 28 strikes the spindle 27 down
and the connections to the nozzles 22 are opened.
The cabin sprinklers 6 are preferably in
principle like the sprinkler llb; one of the nozzles
or an additional connection arranged in the same way
can via the line 7 be connected to the spray head 8 in
the wall 9 of the shower room.
Regarding the detailed structure and function of
the sprinklers 6, 11 and the spray heads reference is
made to the international patent publication numbers
WO 92/015370, WO 92/020453 and WO 92/022353.
The spray head 8 in the wall 9 of the shower room
comprises a central spindle 31 which under the
influence of the liquid pressure in the feed line 7 ,
upon connection by the cabin sprinkler 6, strikes to
the right in figur 4 and thereby presses off a cover
32 and opens connections to the nozzles 33. These
nozzles produce a suction from the cabin through
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apertures 35 in the sprinkler holder 34 into the
shower room and further out.
Figure 5 illustrates an application of the
invention for a larger space or for a part thereof,
e.g. a restaurant. A number of out-going ventilation
ducts, preferably in or at the ceiling, are designated
40, a number of pipe elements from the space to the
ventilation ducts 40 are designated 41 and double
direction sprinkler means mounted in these pipe
elements are designated 42., corresponding to numerals
5, 10 and 11 in figure 1. A number of sprinklers
comparable to the cabin sprinklers 6 in figures 1 and
2 are designated 43. If desired, the sprinklers 43 can
be arranged to upon release also activate neighbouring
sprinklers or spray heads, e.g. according to the same
principle as for the combination sprinkler 6 - spray
head 8 in figures 1 and 2.
The installation works in principle in the same
way as earlier has been described with reference to
figures 1-3, preferably in such a way that all suction
points 41 are activated at the first smoke alarm.
The invention has in the foregoing been described
in connection with an installation including means for
actual fire extinguishing. The invention can, however,
also be used independently for smoke removal, e.g. as
a complement in existing buildings which already have
some kind of fire fighting installation. The smoke
removal can then be made to work without a connection
to the rest of the fire fighting installation,
although not necessarily. It is even possible to
contemplate embodiments with smoke removal only,
without sprinkler means for actual fire extinguishing.
