Patent Grant
8083003
The present invention relates to a fire-extinguishing device with a container holding a fire-extinguishing substance and a compressed gas cylinder which is particularly suitable for use together with this fire-extinguishing substance container.
A large number of fire-extinguishing devices of the most widely varied types with fire-extinguishing substance containers are known. In principle, a distinction may be drawn between portable fire-extinguishing devices and stationary or mobile fire-extinguishing devices. The former are particularly suitable for manual use, whereas the latter are often used in automatic fire-extinguishing systems or fire trolleys.
Many fire-extinguishing devices, in particular portable ones, have the disadvantage that they cannot be used reliably in any desired spatial orientation, i.e. the fire-extinguishing substance cannot be fully discharged in any orientation.
This problem may be avoided if a solid piston or a flexible membrane is arranged movably in the fire-extinguishing substance container and separates a fire-extinguishing substance compartment from a propellant compartment, which serves at the same time as an expansion compartment.
Such fire-extinguishing substance containers are known in particular in connection with automatic fire-extinguishing systems. These have the particular advantage over the above-described fire-extinguishing devices that complete expulsion of the fire-extinguishing substance is ensured with any desired spatial orientation of the fire-extinguishing substance container. They are therefore already used in automatic fire-extinguishing systems installed fixedly in vehicles, where an accident could lead to any orientation of the fire-extinguishing substance container.
A fire-extinguishing substance container with piston is described in WO 96/36398. This is particularly suitable for enclosed spaces, for example passenger compartments or engine compartments, and comprises a fire-extinguishing substance container with a cylindrical container shell closed at both ends and a piston axially displaceable in the container shell. In the fire-extinguishing substance container the piston separates a fire-extinguishing substance compartment, which contains a fire-extinguishing substance, from a propellant compartment, which contains a pressurized propellant gas.
The fire-extinguishing substance compartment is provided with a trip valve at an outlet for the fire-extinguishing substance. In the event of activation of the trip valve, the propellant gas may propel fire-extinguishing substance out of the fire-extinguishing substance container by displacing the piston into the fire-extinguishing substance compartment.
However, a fire-extinguishing device with a fire-extinguishing substance container according to WO 96/36398 has the particular disadvantage that the pressure of the fire-extinguishing substance is not constant during discharge thereof. To ensure complete discharge, the volume of the propellant gas has to be expanded considerably. However, this entails a severe drop in the pressure of the propellant gas and consequently also of the fire-extinguishing substance during expulsion of the fire-extinguishing substance (with no change in temperature). This means that the throughput of fire-extinguishing substance falls over the fire-extinguishing process. Furthermore, as discharge proceeds, the fire-extinguishing substance pressure becomes less well matched to conventionally connected atomizing nozzles for the fire-extinguishing substance of such a system.
U.S. Pat. No. 4,889,189 describes the design of a fire-extinguishing substance container with an internal, expandable membrane which separates the fire-extinguishing substance compartment from the propellant compartment. Furthermore, a method is described for selecting an optimum quantity of fire-extinguishing substance and a most suitable propellant pressure. The design and the method according to U.S. Pat. No. 4,889,189 are directed, inter alia, towards reducing the above-stated disadvantageous pressure drop. However, the drop in fire-extinguishing substance pressure and fire-extinguishing substance throughput during the extinguishing process cannot be prevented satisfactorily either with this fire-extinguishing substance container or with this method.
A further design-dependent problem of known fire-extinguishing substance containers with piston or membrane is caused by the fact that both propellant and fire-extinguishing substance are permanently under nominal pressure over the service life of the fire-extinguishing device (conventionally of the order of magnitude of 100 bar or more). This increases the leakage risk of both substances, so reducing the reliability of the fire-extinguishing device.
Furthermore, the design of the fire-extinguishing substance container and connected fittings is subject to relatively stringent requirements.
The invention proposes a fire-extinguishing device which is functional in any desired spatial orientation and ensures increased reliability.
The invention provides a fire-extinguishing device comprising a fire-extinguishing substance container with a container shell closed at both ends and a piston displaceable axially in the container shell, which piston separates a fire-extinguishing substance compartment from an expansion compartment in the fire-extinguishing substance container. According to the invention, an internal compressed gas reservoir is provided in the fire-extinguishing substance container. The compressed gas reservoir forms a compressed gas chamber separated spatially from the expansion compartment. The compressed gas chamber serves to store a propellant gas under high storage pressure and for controlled pressurization of the expansion compartment with reduced extinguishing pressure. The piston is arranged to be displaceable along the compressed gas chamber.
The compressed gas chamber according to the invention, incorporated into the container by the compressed gas reservoir, is independent of the expansion compartment, and thus also of the variable volume of the expansion compartment serving to accommodate the propellant. In this way it is possible on the one hand to use suitable switching means to prevent the expansion compartment and the fire-extinguishing substance from being under operating pressure when non-operative, while on the other hand this arrangement makes it possible, using suitable pressure control means, to achieve controlled pressurization of the expansion compartment, in particular with a relatively constant low pressure over the entire duration of fire-extinguishing substance discharge. With the design according to the invention, the propellant pressure in the expansion compartment and consequently also the fire-extinguishing (substance) pressure is not only substantially constant over the duration of fire-extinguishing substance discharge but is also freely selectable as regards absolute value and thus adaptable to various applications. Furthermore, a compact, space-saving construction of the fire-extinguishing device is obtained, which combines fire-extinguishing substance container and pressure medium source in one unit. In this way, this fire-extinguishing device is of particularly interest for use in vehicles for transporting goods and people. A complex line arrangement, as arises when separate, external pressure reservoirs are used as the pressure medium source, is very largely dispensed with, so resulting in increased safety and reliability as well as a reduction in costs.
In a construction of advantageous design, the container shell is cylindrical and the compressed gas chamber is arranged coaxially to the container shell in the fire-extinguishing substance container. An annular piston suitable for a coaxial compressed gas chamber has a circular-cylindrical external shape, for example, and is provided with a coaxial circular-cylindrical guide opening.
In a first possible configuration, a compressed gas cylinder located inside the fire-extinguishing substance container and having an at least partially cylindrical outer wall is provided as the compressed gas reservoir. The piston is designed as an annular piston and guided displaceably along the cylindrical part of the outer wall of the compressed gas cylinder. In this configuration, the compressed gas chamber is formed of a, preferably specially machined, compressed gas cylinder, such that the piston may be mounted displaceably on the cylinder itself, so saving on an additional guide.
In a second possible configuration, the fire-extinguishing device comprises a cylindrical guide shell located inside the fire-extinguishing substance container and a compressed gas cylinder, which is arranged within the cylindrical guide shell, is provided as the compressed gas reservoir. The piston is here designed as an annular piston and guided displaceably along the cylindrical guide shell. The essential difference from the first configuration consists in the fact that a conventional compressed gas cylinder may be used as a compressed gas reservoir, i.e. to provide the compressed gas chamber, and may be incorporated into the fire-extinguishing substance container. However this requires the use of a separate guide for the piston.
Furthermore, a switching valve is preferably provided for controlled pressurization of the expansion compartment, which valve is connected on the inlet side to the compressed gas chamber and on the outlet side to the expansion compartment, in order to supply the expansion compartment with compressed gas by opening the switching valve. In addition to the switching valve, the fire-extinguishing device advantageously also comprises a pressure control valve for controlled pressurization of the expansion compartment, which latter valve is connected to the inlet or outlet of the switching valve, in order to pressurize the expansion compartment with compressed gas at a predetermined, substantially constant pressure during the extinguishing process. To control the switching valve, a preferred configuration provides that the switching valve comprises at least one pneumatic control port, and a temperature-sensitive, pressurized detector line is present, which is connected to the pneumatic control port of the switching valve in order to open the switching valve in the event of a pressure drop in the detector line. This makes possible simple and reliable automatic triggering of the fire-extinguishing device if necessary.
In one possible configuration, the fire-extinguishing device comprises a switching valve with a first and a second pneumatic control port, a first pressure control valve, and a port for a detector line, the first pressure control valve being connected on the inlet side directly to the compressed gas chamber and on the outlet side to the inlet of the switching valve, the port for the detector line being connected to the first control port and the outlet of the first pressure control valve being additionally connected to the second control port, and the switching valve being connected on the outlet side to the expansion compartment. This configuration is particularly suitable for expulsion of fire-extinguishing substance under a moderate pressure, which matches that in the detector line.
In a further possible configuration, the fire-extinguishing device additionally comprises a second pressure control valve, which is connected on the inlet side to the outlet of the first pressure control valve and on the outlet side to the inlet of the switching valve or on the inlet side to the outlet of the switching valve and on the outlet side to the expansion compartment. This configuration Is particularly suitable for expelling fire-extinguishing substance at a low pressure, which is lower than that in the detector line.
In another possible configuration the fire-extinguishing device additionally comprises a second pressure control valve, which is connected on the inlet side to the first control port and on the outlet side to the port for the detector line. This configuration is particularly suitable for expelling fire-extinguishing substance at a high pressure, which is higher than that in the detector line.
Preferably, the fire-extinguishing device further comprises an equalizing line for compensating leaks in the detector line, this being connected to the outlet of the first pressure control valve and to the port for the detector line, a non-return valve being arranged in the equalizing line and preventing an excessive loss of propellant via the equalizing line in the event of a significant pressure loss in the detector line.
Preferably, the fire-extinguishing device further comprises a creeping gas safety device, which is connected to the outlet of the switching valve to prevent a creeping pressure build-up in the expansion compartment.
In a particularly compact and robust construction, the fire-extinguishing device further comprises a compressed gas cylinder located inside the fire-extinguishing substance container, the compressed gas cylinder comprising the pressure chamber and a thickened cylinder bottom, which in the form of a fittings block accommodates at least the switching valve, the first pressure control valve and, if applicable, the second pressure control valve. In this case, it is advantageous for the connecting line, which leads via the switching valve, the first pressure control valve and optionally the second pressure control valve from the pressure chamber to the expansion compartment, to be formed by bores in the fittings block. In this construction, the fire-extinguishing device is even more compact, leakproof, and robust.
When a compressed gas cylinder is used which is located inside the fire-extinguishing substance container, sizing in which the compressed gas cylinder occupies 10% to 35% of the useful volume of the fire-extinguishing substance container has proven to be preferable.
In contrast to the prior art, the configuration of the fire-extinguishing substance container proposed herein makes it possible for the fire-extinguishing substance container to be designed for a relatively low (extinguishing) pressure of for example <90 bar although the propellant gas is stored at a substantially higher storage pressure of for example >150 bar in the separate compressed gas reservoir.
In order to accommodate the largest possible volume of fire-extinguishing substance in the container, it is advantageous for the piston to comprise an inner guide bush for guidance against the cylindrical part of the compressed gas cylinder or against the guide shell and an outer guide skirt for guidance against the container shell, the guide bush extending less far axially than the guide skirt. In this way, the piston may be acted upon by propellant from the middle of the container even when in the end position.
The piston is preferably guided against the compressed gas chamber by means of an opening corresponding to the cross-section of the latter, such that it surrounds the compressed gas chamber. It is likewise possible to arrange piston and compressed gas chamber with complementary cross sections in the container shell in such a way that the piston does not surround the compressed gas chamber.
The present invention also relates, independently of the fire-extinguishing device, to a specially developed compressed gas cylinder and in particular to the production method therefore. Without limitation to this application, the use of such a special compressed gas cylinder is particularly advantageous in the fire-extinguishing device according to the invention.
A production method according to the invention for such a compressed gas cylinder comprises the following steps:
According to the invention, the production method is characterized in that
In the method, the solid, thickened base plate preferably takes the form of a cylindrical solid body, which, after indirect extrusion, has the same radius as that of the cylindrical cylinder shell.
Processing of the compressed gas cylinder blank to produce a compressed gas cylinder preferably includes the formation of at least one housing and valve seat bore as a receiving bore for a valve.
For connection of the valve(s) to be incorporated into the cylinder bottom, processing of the compressed gas cylinder blank to produce a compressed gas cylinder advantageously includes the formation of at least one connecting bore from the receiving bore to the interior of the compressed gas cylinder and at least one outlet bore from the receiving bore to the outside in the thickened, solid base plate.
To allow full installation of the necessary fittings, in the method the indirect extrusion is advantageously performed in such a way that the base plate extends in the longitudinal direction of the compressed gas cylinder by 5 to 15 times the wall thickness of the cylinder shell or at least 50 mm.
To produce a compressed gas cylinder In particular for more complex applications, the processing of the compressed gas cylinder blank to produce a compressed gas cylinder additionally preferably includes the following steps:
In this way, all the necessary machining steps for the fittings block may be performed from the end face of the cylinder bottom. Rechucking of the workpiece is unnecessary. It is made simply possible to incorporate the connecting lines between the fittings into the cylinder bottom designed as a fittings block.
If it is intended to utilize the compressed gas cylinder as a guide for a piston in a fire-extinguishing substance container according to the invention, the processing of the compressed gas cylinder blank to produce a compressed gas cylinder preferably additionally includes machining the outer surface of the cylinder shell as a cylindrical guide by material-removing shaping.
A number of configurations of the invention will now be described in greater detail below with reference to the attached, illustrative Figures. In the Figures identical or primed reference signs are used throughout for identical or similar components. In the drawings:
In the case of the embodiment according to
The internal volume defined by the guide shell 18′ is closed relative to the outside and the fire-extinguishing substance compartment 22′ by suitable seals. The piston 20′ is provided with per se known O-ring seals at the inner surface of the container shell 12′ and at the guide shell 18′, which reliably prevent penetration of fire-extinguishing substance into the expansion compartment 24′ and penetration of propellant gas into the fire-extinguishing substance compartment 22′ even in the relatively long term, without the displaceability of the piston 20′ being impaired disadvantageously.
The principle of operation of the fire-extinguishing substance container 10′ may be summarized as follows. When ready for service, the fire-extinguishing substance compartment 22′ is filled with a fire-extinguishing substance, such as for example water combined with an additive. Neither the fire-extinguishing substance compartment 22′ nor the expansion compartment 24′ are initially under pressure, i.e. the constant fire-extinguishing substance pressure in the ready for service state may be at atmospheric pressure, for example. In actual fact, the expansion compartment 24′ is isolated when ready for service from the compressed gas cylinder 28′ by a switching valve 32′ in the fittings block 30′. When necessary, the switching valve 32′ is tripped, for example by a detector device described below, such that only upon tripping does the propellant gas flow out of the compressed gas chamber 26′ into the expansion compartment 24′ (only from this point does the expansion compartment act as a “propellant compartment” for receiving the propellant from the compressed gas chamber as with the device known from WO 96/36398). The propellant gas is then preferably adjusted down to a predetermined extinguishing pressure, for example 4 bar, 15 bar or 90 bar by a pressure control valve or a pressure reducing valve in the fittings block 30′ (not shown in
Before the second, further developed embodiment of the invention according to
Connected directly to the outlet of the compressed gas cylinder 28 is a first pressure control valve 52, which reduces a storage pressure p1 (e.g. 200 bar) of the propellant in the compressed gas cylinder 28 to a first intermediate pressure p2 (e.g. 15 bar). A switching valve 32 is connected to the outlet of the pressure control valve 52. The switching valve 32 is, for example, a 2/2-way valve with blocking in the counterflow direction and comprising pneumatic control ports 56, 58. The outlet of the switching valve 32 is connected to a second pressure control valve 60, which reduces the intermediate pressure p2 to a propelling pressure or extinguishing pressure p3 (for example 4 bar) for the expansion compartment 24. Alternatively, the pressure control valve 60 could also be arranged directly upstream of the switching valve 32. The outlet of the second pressure control valve 60 is connected via a spring-loaded pressure relief valve 62 (or a rupture diaphragm) to the expansion compartment 24 of the fire-extinguishing substance container 10. The pressure relief valve 62 is set to a specific minimum pressure (less than p3), which must be applied in order to fill the expansion compartment. Furthermore, the outlet of the switching valve 32 is connected to the outside via a creeping gas safety device 64.
The non-ideal long-term sealing of the switching valve 32 is compensated by means of preferably likewise non-ideal or poorer long-term sealing of the creeping gas safety device 64 relative to the outside. This, together with suitable pretensioning at the non-return valve 62, prevents a creeping pressure build-up in the expansion compartment 24. The creeping gas safety device 64 does not dissipate short-term pressure changes, however.
When ready for service, the ball valve 70 is open, such that the detector line 70 is connected directly to the first control port 56 of the switching valve 32. The ball valve 70 serves inter alia for replacement of the detector line 74 after use. The detector line 74 comprises a special hose, which is pressurized with gaseous pressure medium. This pressurized special hose is fitted above a point 76 potentially at risk of fire. It consists of a specially developed, ageing-resistant, diffusion-tight polymer material and is designed such that the hose wall bursts open for example at a temperature of between 100 and 110° C. and allows the gaseous pressure medium to escape. Furthermore, as shown in
The mode of operation of the fire-extinguishing device 50 with the detector line 74 will be described in brief below. When ready for service, the pressure in the detector line 74 is set to p2, i.e. equal to the pressure at the outlet of the first pressure control valve 52. As soon as the pressure in the detector line 74 drops, a pressure difference arises between the control ports 56, 58, whereby the switching valve 32 opens without external energy. A pressure drop in the detector line 74 naturally arises when, in the event of fire, the detector line 74 bursts open through the action of heat at any point, in particular at the at-risk point 76 requiring protection. When the switching valve 32 is open, the expansion compartment 24 is supplied with propellant at a constant pressure p3 from the compressed gas cylinder 28 via the two pressure control valves 52, 60.
In this way, the piston 20 is moved towards the fire-extinguishing substance compartment 24, such that the latter decreases continuously in size, and the fire-extinguishing substance is propelled out of the fire-extinguishing substance container 10 via the pressure relief valve 36. It should be noted that, due to the above-described arrangement, the fire-extinguishing substance is expelled at a constant throughput and pressure p3 over the entire discharge period.
The fire-extinguishing substance is conveyed to atomizing nozzles 84 of known construction via a fire-extinguishing substance line 82, to which nozzles the pressure p3 of the fire-extinguishing substance is optimally matched over the entire extinguishing process. The fire-extinguishing substance, which fights the fire, is discharged via the atomizing nozzles 84 at the location at risk.
With reference to
In addition to a further view of the switching valve 32 and the bursting disc device 88,
The non-operative and initial position of the control piston 96 is set to “closed”, i.e. in abutment against the closed end of the blind bore 103. This is achieved by means of appropriately selected pressure effect cross-sections on the control piston 96 of the control valve 32. If a positive pressure difference arises between the first control port 56 and the second control port 58, i.e. the pressure at the control port 56 is less than at the control port 58, the control piston 96 is displaced towards the first control port 56 into the “open” position. In this way, a passage is opened up from the inlet of the control valve 32 (which coincides with the second control port) via the transverse bore 105 to the outlet of the control valve, i.e. towards the second pressure control valve 60.
Production of the novel compressed gas cylinder 28 according to
The method is characterized in that on the one hand the indirect extrusion is performed in such a way that the cylinder bottom takes the form of a solid, thickened base plate 202, i.e. of a solid body, and on the other hand processing of the compressed gas cylinder blank 200 to produce a compressed gas cylinder at least includes formation of a receiving bore for a valve in the solid, thickened base plate 202.
Formation of a receiving bore for a valve during processing of the compressed gas cylinder blank 200 to produce a compressed gas cylinder 28 includes for example formation of at least one housing and valve seat bore (89; 95; 97), and in general at least one connecting bore (91; 93) to the interior of the compressed gas cylinder and at least one outlet bore (115) to the outside in the thickened, solid base plate 202. Such receiving and connecting bores produce from the originally solid, thickened cylinder bottom 202 a fittings block 30 in which the valves and fittings necessary for use of the compressed gas cylinder 28 may be fully installed. A variant of a compressed gas cylinder 280 produced in this way is shown in
It should be noted that by means of such a production method a compressed gas cylinder 28, 280 is produced in which a fittings block 30 is an integral component of the compressed gas cylinder 28, 280. This is made possible in particular by the solid, thickened base plate 202 produced during indirect extrusion, which forms the cylinder bottom and serves as a base member for the fittings block 30 produced later in the method.
To be able to accommodate the valves and fittings, the solid, thickened base plate 202 extends preferably at least 50 mm after indirect extrusion and may amount to 5 to 15 times the wall thickness of the cylinder shell.
Of course, a plurality of housing and valve seat bores (89; 95; 97) may be accommodated in the solid, thickened base plate 202. The line connections between the valves installed later therein are preferably formed by connecting bores (99, 101, 107) in the thickened, solid base plate 202, which bores extend obliquely relative to the longitudinal axis of the compressed gas cylinder.
This makes it possible to effect machining of the compressed gas cylinder blank 200 very largely from the end face of the base plate 202. As is apparent from FIGS. 2 and 7-13, the housing and valve seat bore (89; 95; 97) are multistage bores, which correspond to the components to be accommodated.
With regard in particular to a compressed gas cylinder 280 as shown in
It goes without saying that not all of these steps are necessary for producing a compressed gas cylinder with valves and fittings incorporated into the cylinder bottom. Important advantages of such a compressed gas cylinder 28, 280 are for example:
It should be noted that such a novel compressed gas cylinder may prove eminently advantageous in other fields of application. It is of interest in particular for applications where safety is important, for example in the medical field in addition to fire-extinguishing technology, for example for emergency breathing apparatus, due to the avoidance of potential damage or shearing off of the valves/fittings during transportation of the compressed gas cylinder. The compact and safe construction of such a compressed gas cylinder is also advantageous in other fields in which small cylinder systems are used, such as for example in beverage technology for the carbonation of beverages.
Finally, some of the various advantages of both embodiments of the fire-extinguishing substance container according to
The second embodiment according to
On the one hand, this fire-extinguishing substance container 10 is of a particularly space-saving construction, since special holders for the compressed gas cylinder 28 are dispensed with, and the fittings are installed as far as possible in the fittings block 30 incorporated into the compressed gas cylinder 28. This latter additionally protects the fittings from damage, for example in the event of transportation or of improper use. Furthermore, storage of the propellant gas is improved with regard to the leakproofness thereof, in that at least one sealing surface between cylinder neck and fittings is dispensed with.
Finally, it should be noted that each of the fire-extinguishing devices 50, 50″, 5′″ forms an automatic safety device operating without external energy, which is triggered automatically in the event of fire.
| Number | Date | Country | Kind |
|---|---|---|---|
| 061000139 | Jan 2006 | EP | regional |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP2006/070259 | 12/12/2006 | WO | 00 | 3/23/2009 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2007/077195 | 7/12/2007 | WO | A |
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|---|---|---|---|
| 2960369 | Goldie | Nov 1960 | A |
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| 4889189 | Rozniecki et al. | Dec 1989 | A |
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| 5845716 | Birk | Dec 1998 | A |
| 5984016 | Samuelsson | Nov 1999 | A |
| 6047777 | Eisenbeiss et al. | Apr 2000 | A |
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| 7325622 | Sjostrom | Feb 2008 | B2 |
| 20050173132 | Sjostrom | Aug 2005 | A1 |
| Number | Date | Country |
|---|---|---|
| 866485 | Aug 1978 | BE |
| 9636398 | Nov 1996 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 20100116515 A1 | May 2010 | US |
