Installation for fighting fire in a plurality of fire sections

An installation for fighting fire has a drive unit for extinguishing liquid. A main feed line (5) of the drive unit (1) is connected to a pilot valve having outgoing lines to a plurality of fire sections (A, B, C, D) for opening connection between one of the fire sections (A) and the main feed line (5) and closing of connections from the other fire sections (B, C, D) and the main feed line (5).

The present invention relates to an installation for fighting fire, 
comprising a drive unit for extinguishing liquid. 
In the Finnish patent application 924752 (see international patent 
publication WO 94/08659); is described an installation for fighting fire 
having as a drive unit e.g., a plurality of parallel hydraulic 
accumulators with an initial charge pressure of, e.g., about 200 bar. Such 
an installation is well suited for fighting fire, e.g., in an engine room 
of a ship. The engine room is usually divided into a number of separate 
fire sections or fire zones. 
It is desirable to connect the drive unit of the fire fighting installation 
selectively to that particular fire section where a fire has started. High 
pressure guide or pilot valves are available for that purpose but they are 
expensive. 
The object of the invention is to provide, for an installation of the kind 
mentioned above, a new pilot valve means which is of a simple structure 
and thus is cheap. 
The basic idea of the invention is that after an alarm signal has been 
received, but before actuating the drive unit of the fire fighting 
installation, the desired flow path is opened through the pilot valve 
means to connect the drive unit for extinguishing liquid to the respective 
fire section. Thanks to the invention it is possible to use simple and 
cheap pilot valves dimensioned for low pressure, or alternatively, small 
pilot valves intended for high pressure which likewise are cheap. 
According to a preferred embodiment of the invention, liquid is in a first 
step delivered at a relatively low pressure, e.g., about 20 bar, in order 
to fill the lines leading to the respective fire section with liquid and 
to cool the respective spray heads and nozzles before actuating the drive 
unit intended for high pressure liquid spraying, and by utilizing the 
initial low pressure liquid the connection from the outgoing line of the 
drive unit is at the same time opened through the pilot valve means to the 
respective fire section. The outgoing line is still closed at the drive 
unit during the initial step of combined low pressure spray and opening 
said connection through the pilot valve means, and thus it is possible to 
use pilot valves dimensioned for low pressure. 
The initial spraying of low pressure liquid as well as establishing the 
connection from the respective fire section to the main drive unit of the 
installation can, alternatively, be accomplished by means of, e.g., a 
hydraulic accumulator which can be charged to either a high pressure or a 
low pressure. If the accumulator is charged to a high pressure, the 
connection thereof to the respective outgoing fire section line is 
arranged through a small high pressure valve which passes a small flow of 
liquid. Instead of a separate hydraulic accumulator it is also possible to 
for this purpose use the main drive unit itself which preferably comprises 
a plurality of hydraulic accumulators coupled in parallel, whereat thus 
the drive unit at first is connected to the pilot valve means through a 
small high pressure valve in order to, before commencing the main 
extinguishing procedure, open such a connection from the respective fire 
section to the main drive unit that is capable of passing the whole liquid 
delivery capacity of the drive unit. 
By a small high pressure valve, which acts as a pilot valve within the 
pilot valve means, is here meant a valve having a pass flow aperture 
diameter of the order, e.g., 2 mm. In comparison, if one were to actuate 
the drive unit directly at full power, the pilot valve means would require 
high pressure valves having a pass flow aperture diameter of about 40 mm. 
It is essential to perform the establishment of the desired connection in 
the pilot valve means, intended for the main extinguishing process, by 
means of a small power, i.e., either by utilizing a low drive pressure, 
whereat the amount of liquid can be relatively great, although 
considerably smaller than the main flow during the main extinguishing 
process, or by utilizing a high pressure and a small amount of liquid.

In FIG. 1 a drive unit for delivering high pressure extinguishing liquid in 
a fire fighting installation is generally indicated by the reference 
numeral 1. A pilot valve means leads from the drive unit 1 to four fire 
sections A, B, C and D. A liquid pump with an operating pressure of, e.g., 
15 to 20 bar is indicated by 2 and a high pressure liquid pump with an 
operating pressure of, e.g., 200 bar is indicated by 3. The high pressure 
pump 3 is arranged to charge a plurality of hydraulic accumulators 4 which 
preferably are of a structure as described in the Finnish patent 
application 924752 (see international patent publication WO 94/08659). The 
outgoing line of the drive unit 1 is indicated by 5 and a shut-off valve 
in the line 5 is indicated by 6. The valve 6 is usually open, as in FIG. 
1. 
FIG. 1 shows the installation in an inactive state of standby. 
In FIG. 2, a fire has broken out in fire section A. The pump 2 has been 
activated to deliver liquid through its feed line 7 (alternatively, e.g. 
in case of electric power fallout, initial pilot liquid can be delivered 
by a low pressure hydraulic accumulator 8), through the opened valve 9 and 
a subsequent back valve to the line 10 which leads to spray heads or 
sprinklers in the fire section A. The pressure in the line 10 moves a 
first change valve 11, positioned between the feed line to the fire 
section A and the feed line to the fire section B, from the position shown 
in FIG. 1 to the position shown in FIG. 2, and a second change valve 12 
likewise from the position shown in FIG. 1 to the position shown in FIG. 
2. The delivery of low pressure liquid to the fire section A thus opens 
the connection from the feed line 5 of the high pressure drive unit 1, 
when the hydraulic accumulators 4 are not yet activated, to the fire 
section A, while the connections from the feed line 5 of the drive unit 1 
to the fire sections B, C, and D are closed. 
The high pressure unit 1 can now be activated at will. The valve 9, as well 
as the corresponding valves to the fire sections B, C, and D, can be of a 
simple and cheap structure. 
FIG. 2 also differs from FIG. 1 in showing a hydraulic high pressure 
accumulator 100 separate from the drive unit 1 previously described. 
Between the feed lines to the fire sections C and D is provided a third 
change valve 13 which in the present case has not moved. The positions of 
the change valves 12 and 13 in FIG. 1 indicate that the previous 
activation, e.g., in order to test the installation, has occurred in the 
fire section D which in FIG. 1 is in connection to the feed line 5 of the 
drive unit 1, while the connections to the fire sections A, B, and C are 
closed. 
The valve arrangement 11, 12, 13 can be of a simple structure. FIG. 3 shows 
one embodiment where the change valves 11, 12, and 13 comprise movable 
sleeves 21, 22, and 23, respectively, with one end closed. If desirable, 
the pilot valve means can without difficulty be extended to serve a larger 
number of fire sections, utilizing the same principle. 
FIGS. 1-3 show a favorable embodiment of the invention. It is, however, 
possible to replace the low pressure valves 9 by small high pressure 
valves 90 (FIG. 2), whereat it for the initial low pressure liquid 
spraying and simultaneous establishing of the respective connection via 
the change valves 11, 12, and 13, respectively, is possible to use a 
hydraulic high pressure accumulator 100 (FIG. 2) which could replace the 
low pressure hydraulic accumulator 8 and be charged by the high pressure 
pump 3. The valves 11, 12, and 13 could in principle also be actuated by 
means of pressurized gas, if it is considered unnecessary to initially 
cool the nozzles and the spray heads and to fill the feed lines with 
liquid before the high pressure drive unit 1 is activated. 
Alternatively, it is further possible to utilize the hydraulic high 
pressure accumulators for establishing a connection to a respective fire 
section. An example is shown in FIG. 4. 
From the bottom region of a hydraulic accumulator 4 runs a pipe 30, 
preferably provided with apertures in its wall, as presented in the 
Finnish patent application 924752 (see international patent publication WO 
94/08659), to a valve structure at the outlet end of the accumulator 4. 
From the pipe 30 leads a throttled connection 31 in a valve spindle 32, 
which is forced against the outlet end of the pipe 30 by a spring 33, to a 
narrow gap 34 between the spindle end of a manually operable valve 35 and 
the housing of the outlet valve structure. From the passage 34 there is a 
line 36 to a pilot valve means which in principle is of the same kind as 
the one shown in FIGS. 1-3. The line 36 corresponds to the line 7 or to 
the feed line of the hydraulic low pressure accumulator 8 in FIG. 1, while 
the line 37 in FIG. 4 corresponds to the main feed line 5 in FIG. 1. 
In FIG. 4 the installation is in a state of standby, whereat the pressure 
in the line 36 is the same as in the accumulator 4, via the connection 
31-34. The line 36 can be filled with liquid but there is no liquid flow 
in the line 36, because the valves 9 to the fire sections A, B, C, and D 
are all closed. 
It shall again be assumed that there is a fire in the fire section A. Alarm 
results in that the respective valve 9 is opened and liquid flows from the 
line 36 to the section A and at the same time the valves 11 and 12 are 
moved to the positions of FIG. 2 in the same way as described earlier, 
establishing connection from the section A to the line 37. The pressure in 
the line 37 has access, via a groove 38 or the like formed in the valve 
spindle 32, to act on a face 39 of the spindle 32, in a direction against 
the spring 33, whereat the force effected by the pressure on said face 39 
together with the force effected by the pressure in the accumulator 4, due 
to the pressure fall over the throttle 31, drive the valve spindle 32 
upwards from the position shown in FIG. 4, so that there is a direct 
connection from the outlet of the pipe 30 to the line 37, for full 
delivery of liquid to section A. 
The embodiment shown in FIG. 4 can without difficulty be extended to 
comprise a plurality of hydraulic accumulators 4, e.g., as shown in FIG. 
1. This embodiment has an additional advantage in that it is fully 
workable independently of electric power supply; the valve symbols in FIG. 
4 indicate that the valves in first place are intended to be operated 
automatically, e.g., electrically, with a possibility to be manually 
operated, as a reserve. With suitable dimensions for the throttles at 31 
and 34, the valves 9 in FIG. 4 can be low pressure valves, like in FIGS. 
1-3, or alternatively high pressure valves with a small pass flow 
aperture. 
The spray heads, including nozzles, of the installation, in the respective 
fire sections A, B, C, and D can preferably be of such constructions that 
are presented, e.g., in the international patent applications 
PCT/FI92/00060, PCT/FI92/00155, and PCT/FI92/00156, which are WO 92/15370, 
WO 92/20443 and WO 92/20454, respectively. 
Thus, important aspects of the invention are: 
An installation for fighting fires comprising a drive unit 1 for 
extinguishing liquid including a pressure source, a main feed line 5 
connected to said pressure source, and a pilot valve means, having 
outgoing lines to a plurality of fire sections A, B, C, D connectable to 
said pressure source, for connecting said pressure source to one said 
outgoing line 10 to one said fire section A for opening a connection 11, 
12 between said one fire section A and said main feed line 5 of said drive 
unit 1 and for closing connections between all other said fire sections B, 
C, D and said main feed line 5 of said drive unit 1; 
an installation wherein said pilot valve means comprises change valves 11, 
12, 13 and wherein said outgoing lines are interconnected pairwise A, B,; 
C, D by at least one of said change valves 11; 13, another one of said 
change valves 12, further interconnecting said pairwisely interconnected 
outgoing lines and being directly connected to said main feed line 5; 
an installation wherein change elements of said change valves 11, 12, 13 
are axially movable sleeves 21, 22, 23; 
an installation wherein said pressure source is a liquid source 3; 8 having 
a low operating pressure in relation to an operating pressure of said 
drive unit 1; 
an installation wherein said liquid source 3; 8 is connected to each said 
outgoing line 10 through a low pressure valve 9; 
an installation wherein said pressure source is a high pressure liquid 
source connected to each said outgoing line through a small high pressure 
valve; 
an installation wherein said high pressure liquid source is a hydraulic 
high pressure accumulator 100 separate from said drive unit 1; 
an installation wherein said high pressure liquid source is part of said 
drive unit 1;4; 
an installation wherein a throttle 31 passes an initial pilot liquid flow, 
said throttle 31 being in a spindle 32 of 
an outlet valve of said high pressure liquid source 4, and wherein a 
pressure in a main outgoing line 37 of said liquid source 4, after said 
connection to said one fire section, together with a pressure fall across 
said throttle 31, drives said spindle 32 to open direct connection from 
said liquid source to said main outgoing line 37 of said liquid source 4; 
and 
an installation wherein said pressure in said main outgoing line 37 of said 
liquid source 4 acts through a groove 38 on a face 39 provided on said 
spindle 32.