EP1902757B1 - Propulsion device for an agent contained in a cavity - Google Patents

Abstract

The device has a cover (3) and a workable orifice (5) above calibrated pressure in a cavity (1). A pressure generator (2) has two reservoirs (2a, 2b) with respective outlets (s1, s2) opening interior of the cavity. The reservoirs release gas propulsion on the agent. One of the reservoirs is pressurized with an inert gas e.g. helium, that is adapted for minimal temperature fluctuations induced in the cavity, during pressure detent of the inert gas from another reservoir in the cavity. The inert gas in detent is a direct mechanical propeller of the agent through the orifice. An independent claim is also included for a control method adapted for maintenance of an agent propulsion device.

Description

The present invention relates to a device for propelling an agent contained in a cavity according to the preamble of claim 1. Various uses of said device and a control method adapted for maintenance of the device are also parts of the invention according to the invention. the preambles of claims 21 to 24.

In order to propel a gaseous or liquid agent, devices for propelling the agent contained in a cavity are currently used and comprise at least one cover (for filling the agent in the cavity) and an outlet orifice of the agent outside the cavity, openable above a calibrated pressure in the cavity closed by the lid. In order to open the outlet orifice, for example made in the form of a rupture disk on the wall of the cavity, a pressure generator can be fixed to the lid and therefore to the cavity and induced by electric triggering the propulsion of the agent via the outlet port yielding under the pressure rise due to the pressure generator.

Such devices have applications in several fields, for example in the field of fire suppression or cooling, while the agent is an extinguishing agent or cooling. However, they can be used in other distinct areas that require a propulsion or a rapid and possibly large boost of an agent out of its storage cavity. For the rest of the invention, however, reference will mainly be made to the field of fire suppression or cooling, in particular in the field of means of transport as for an aircraft where several problems the device for propelling an extinguishing agent can arise for example in terms of safety (impact resistance, assurance of the targeted priming of the pressure generator, etc.), the limitation of the volume of the device, its weight, costs, etc. In addition, it is important to specify two aspects that the Applicant wishes to avoid in the present invention, these being related to the manufacture or maintenance of a gas generator, as an initiator of the propulsion of the agent. out of the cavity. The first aspect comes from the fact that the gas generator may be damaged or simply no longer work for an indeterminate reason that could escape ground maintenance and thus disrupt an aircraft shutdown in flight. It is therefore important to propose a propulsion device conducive to being easily and efficiently controlled. The second point is directed towards the known use of a pressure generator containing as main initiator an energy fuel such as a conventional pyrotechnic module. This type of pyrotechnic generator, besides its good propulsive efficiency, requires a complex and expensive manufacturing technique to ensure sufficient operational safety, particularly in the field of aeronautics where safety standards are very strict. If the cavity must contain a large amount of extinguishing agent, a quantity of energetic material can therefore also be high and thus requires high manufacturing and maintenance skills to ensure adequate safety of use of the device.

As an example to avoid a pyrotechnic module, US 5,845,714 proposes a device for propelling an agent contained in a cavity comprising at least one lid and an opening opening above a calibrated pressure in the cavity, for which a pressure generator, external to the cavity, is fixed to the lid and induced by trigger electric propulsion of the agent. The pressure generator comprises at least two tanks respectively having an outlet leading to the interior of the cavity and each releasing a propellant gas on the agent. At least one of the tanks is pressurized with, as propellant gas, an inert type gas, which inert gas expansion is the direct mechanical propellant of the agent via the opening opening. The use of such tanks pressurized with an inert gas therefore advantageously avoids the use of a pyrotechnic module.

An object of the present invention is therefore particularly, among the aforementioned problems, to provide a high-security device for propelling a liquid or gaseous agent out of a cavity provided with a pressure generator.

For this purpose, the invention proposes, on the one hand, such as in the state of the art, a device for propelling a liquid or gaseous agent contained in a cavity comprising at least one lid and an opening that can be opened above a calibrated pressure in the cavity, for which a pressure generator is attached to the cover and induced electric triggering the propulsion of the agent.

A first advantageous aspect of the invention further provides that the pressure generator comprises at least two reservoirs, or at least one of the two reservoirs being disposed in the cavity, respectively having an exit leading to the interior of the cavity (the outputs could also end together in the cavity). The two tanks each release a propellant gas which is used as said propellant to empty the cavity of its agent. In this way, if one of the tanks has a malfunction, the other tank provides at least one propulsion of the agent out of the cavity. Admittedly, this propulsion can then be slowed, but still ensures a fire extinguishing. This reduction of propellant tanks also has many of the advantages that will be described in the rest of the present invention, among others in terms of safety, modularity, pressure profile control required, the flexibility of installation, ease of maintenance, etc.

A second considerably advantageous aspect of the invention is that at least one of the tanks is pressurized (before use of the device) with, as propellant gas, an inert gas adapted for minimal temperature fluctuations induced in the cavity during a pressure expansion of the gas from at least one of the reservoirs to the cavity, which expansion gas is the direct mechanical propellant of the agent via the opening opening. Preferably, the inert gas is helium in gaseous form.

• l'hélium est plus léger que l'air, ce qui permet de concevoir un dispositif de propulsion moins lourd.
• l'hélium a une très faible réactivité chimique, ce qui le rend neutre devant tout accident d'ordre chimique.
• l'hélium est ininflammable, ce qui élimine toute possibilité d'incendie intempestif (ou provoqué) lié au générateur de pression
• l'hélium peut être maintenu aisément sous phase gazeuse dans les températures supérieures à 4.2 K et au besoin sous phase liquide en dessous (à la pression atmosphérique).
• l'hélium a des propriétés remarquables de superfluidité (glissement sans frottements, viscosité faible voire nulle dans la cavité), ce qui lui permet de jouer son rôle de propulseur de l'agent extincteur de façon efficace.
• l'hélium peut s'adapter à des climats rudes (par exemple pour des températures inférieures à -40°C) sans que cela ne provoque une perturbation conséquente de la pression à la sortie d'un réservoir, ce qui est donc déterminant pour obtenir un profil de pression requis pour la propulsion adéquate de l'agent à expulser hors de la cavité. Ceci ne serait pas le cas, si de l'azote était utilisé au lieu de l'hélium, car suivant des différences de température, l'azote induit de fortes et gênantes variations de pression.

Other inert gases could be used. In this regard, it is recalled that the electrons of the last energy level (which corresponds to the last non-empty electronic layer), or valence layer, are responsible for the chemical properties of the element. The last non-empty electronic layer of noble gases (helium, neon, argon, krypton, xenon and radon) is complete. This is why these so-called inert gases are very little reactive. However, the heavier rare gases such as krypton, xenon and radon can participate in chemical reactions and the invention recommends avoiding them. By using helium as a propellant for the extinguishing agent, a number of advantages are thus provided, inter alia:

• helium is lighter than air, which makes it possible to design a lighter propulsion device.
• helium has a very low chemical reactivity, which makes it neutral in the face of any chemical accident.
• helium is non-flammable, eliminating any possibility of accidental (or induced) fire related to the pressure generator
• Helium can be easily maintained in gaseous phase at temperatures above 4.2 K and if necessary in liquid phase below (at atmospheric pressure).
• helium has remarkable properties of superfluidity (sliding without friction, low or no viscosity in the cavity), which allows it to play its role of propellant extinguishing agent effectively.
• helium can adapt to harsh climates (for example for temperatures below -40 ° C) without this causing a significant disturbance of the pressure at the outlet of a tank, which is therefore critical to obtain a pressure profile required for proper propulsion of the agent to be expelled from the cavity. This would not be the case, if nitrogen was used instead of helium, because following temperature differences, nitrogen induces strong and troublesome pressure variations.

Such a system thus makes it possible to overcome or at least greatly minimize the use of energetic materials (fuels) in the pressure generator, because to release the helium, the tanks (we will assume later that all the tanks contain helium, unless otherwise stated) can be triggered electrically then mechanically or at worst by a pyrotechnic type valve whose quantity of energetic materials is tiny (for example a few grams per tank), that is to say say at minimum energy content and only sufficient to trigger the opening of one of the tank outlets releasing helium into the cavity and a fortiori causing the opening of the opening opening of the cavity.

It thus follows from this first very advantageous observation that a use of the device for propelling a liquid or gaseous agent is made possible, for which the introduction of combustible material of an energy nature should be minimal or avoided, because imposes a complex technique to ensure very good reliability, such as in the field of aeronautical, land or maritime transport or in any flammable environment.

In addition, in view of the modularity of the size / geometry of the tanks or their free location relative to the cavity (for example at least one in the cavity itself and the others outside the cavity via a channel to achieve the arrival of helium from a reservoir to the cavity), a device installation infrastructure which is of reduced size and / or imposes a distribution or / and a geometry of the cavity and reservoirs specific to the infrastructure is made possible. This is particularly advantageous for spaces integration of the device where space or security problems arise, such as in aircraft or any other means of travel, but also in buildings whose place is reduced.

Tanks containing helium may be pressurized cartridges, also commonly referred to as "sparklets". These are easily accessible on the market, because they are used for example for the high-speed triggering of vehicle "airbags". From there, these sparklets are also less expensive and a very simplified maintenance compared to a pyrotechnic generator for example. They also have a reduced size, thus facilitating their integration into or out of the cavity.

In a preferred configuration where one of the tanks containing the helium, in addition to its robustness, would burst or trip unexpectedly, the use of the propulsion device is still secure, because a confinement of the pressure generator having its reservoirs. helium inside the cavity closed by the lid is assured. It is understood that the cavity and the lid form a closed set of robustness such that the bursting or the opening of all the tanks at the same time is allowed.

• un témoin de mesure de niveau de l'agent à propulser dans la cavité est fournit au moyen (ou le long) d'un axe fixé dans la cavité et sur lequel les réservoirs peuvent également être fixés,
• un témoin de vidange de la cavité est fournit à travers un capteur d'éclatement de disque de rupture,
• des moyens de remplissage divers d'agent à propulser ou voire d'hélium sous forme pressurisée peuvent être réalisés. Toutefois, si un réservoir d'hélium devait présenter un défaut inattendu, il reste bien entendu aisément interchangeable, voire commutable sur un autre réservoir de sécurité.

A control method can be advantageously adapted for efficient maintenance of the propulsion device. Thus, it is possible to predict the following aspects:

• a level measurement indicator of the agent to be propelled into the cavity is provided by means (or along) of an axis fixed in the cavity and on which the tanks can also be fixed,
• a cavity emptying indicator is provided through a rupture disk burst sensor,
• various filling means of the agent to be propelled or even helium in pressurized form can be realized. However, if a helium tank had to have an unexpected fault, it is of course easily interchangeable or switchable to another safety tank.

A set of subclaims of the present invention also has advantages of the invention.

Figure 1

un dispositif de propulsion d'un agent extincteur selon l'invention,

Figure 2

le même dispositif muni d'une membrane de déploiement,

Figure 3

un système complet et modulable comprenant le dispositif selon l'invention.

Examples of implementation and application are also provided using the figures described:

Figure 1

a device for propelling an extinguishing agent according to the invention,

Figure 2

the same device with a deployment membrane,

Figure 3

a complete and modular system comprising the device according to the invention.

The various figures of the present invention relate to a device for propelling an extinguishing agent, such as FK5-5-1-12, out of a cavity for the sake of clarity. It is of course possible to propel any other liquid and / or gaseous substance, such as a cooling or extinguishing agent.

Figure 1 presents a device for propelling an extinguishing agent 6 according to the invention which for example can be installed on board an aircraft for various fire prevention, such as in a reactor.

The propulsion device of the agent 6 contained in a cavity 1 (here spherical) comprises at least one lid 3 (hermetically recessed / fixable in an upper opening of the cavity 1) and a working orifice 5 (such as a rupture disc above a precalibrated pressure in the cavity 1 for which the extinguishing agent 6 must be expelled), a pressure generator 2 is fixed to the lid 3 and induced by electrical release the propulsion of the agent 6 via the rupture disk 5 in the open state. As the invention recommends, the pressure generator 2 comprises at least two tanks 2a, 2b, - respectively having an outlet s1, s2 leading to the interior cavity 1 and being pressurized with a gas (helium or "He") inert type adapted for minimal temperature fluctuations induced in the cavity during a pressure expansion of the gas (He) from at least one of the reservoirs to the cavity 1, which gas (He) in expansion being the propellant direct mechanics of the extinguishing agent 6 via the opening 5.

The pressure generator 2 comprises at least one opening module (not shown) of the outputs s1, s2 of the tanks 2a, 2b, said opening module may comprise at least one pyrotechnic valve with minimum energy content and sufficient to trigger the opening of each of the outputs s1, s2. Any other form of opening module (mechanical, electrical) to completely avoid the introduction of energetic material is of course possible. The tanks 2a, 2b,... Can also be triggerable by separate electrical tripping or / and are time-delayed starting. They may also have different dimensions and / or gas storage capacities (He). This makes it possible to generate pressure profiles in the cavity or flow rates of extinguishing agent 6 at the outlet 7 of the cavity which are very well controlled because they can easily be modulated in time or intensity depending on the capacity of each reservoir.

In this example, the tanks 2a, 2b are cylindrical conventional sparklets and placed along an axis of revolution of the spherical cavity 1 (materialized by an axial element AX). They may, however, have a geometry and an arrangement adapted to maximize the free volume of filling of the agent 6 in the cavity 1.

At least one of the two reservoirs 2a, 2b is disposed in the cavity 1 by means of a holding base 4 preferably fixed at the level of the cover 3. figure 1 however, it represents two sparklets 2a, 2b both held along the holding base 4 which itself comprises the axial element AX fixed perpendicularly to the cover 3 and the retaining elements 9 of the tanks 2a, 2b, ... arranged around the axial element (AX), here at the lower base of the cavity 1.

A level 8 measurement sensor for filling the extinguishing agent 6 in the cavity 1 is then advantageously integrated on a portion of the axial element AX. It can be very simply realized by a buoy (adapted to float on the surface of the extinguishing agent 6) sliding along the axial element AX indicating the level of the extinguishing agent 6 between the upper pole and the pole cavity of the cavity 1. Other level indicator systems can of course be envisaged,

One of the tanks 2a, 2b, ... may also be used as pressurized pressure booster tank (to allow to modify as desired a thrust profile of the agent in time or intensity) or as a reservoir in case of failure of the other tank (or other possible tanks).

It should also be noted that at least one of the tanks 2a, 2b, ... is, if necessary, easily interchangeable manually or automatically, in particular by a possible switching its output with the output of another tanks 2a, 2b, .... Alternatively, the tanks can be designed to be refillable gas (He) pressurized. Also, the cavity 1 may comprise a filling inlet of the agent 6, for example via the lid 3.Thus, safety and maintenance can be increased.

So according to figure 1 , the gas generator 2 comprises a plurality of tanks 2a, 2b, ... disposed at least on one side of the lid 3, each tank being of cylindrical shape with an axis of revolution perpendicular to the lid 3 (thus along the axial element AX and fixed on the holding base 4) and whose total extent of their cylindrical sections is smaller than that of the cover 3. In this way, the simple withdrawal or the simple closing of the cover 3 allows to remove the whole of the generator of gas 2 with all its tanks for example for various maintenance applications that are thus simplified and accelerated.

It can also be provided that the outlets s1, s2, ... of the tanks 2a, 2b, ... or their arrivals in the cavity 1 are arranged in a gap formed between the cover 3 and the extinguishing agent 6, here at upper pole of the cavity, diametrically opposed to the rupture cap 5 of the cavity 1 where the agent will be expelled after its rupture. The gap may itself comprise deflectors defl defl gas flow (He) outputs s1, s2 tanks 2a, 2b, to better target the pressure zones required for the propulsion of the extinguishing agent 6 out of the cavity 1.

The figure 2 represents the device for propelling the extinguishing agent 6 such as that of the figure 1 but for which at least one of the reservoirs 2a, 2b, ... in the cavity 1 is disposed in a deployment membrane 10 with a closed or closable surface with the cover 3, for example at its circumference 12 inside the cavity 1. This membrane mainly allows a physical separation between the mechanical propellant (helium from one or tanks 2a, 2b, ...) and the extinguishing agent 6 to expel out of the cavity. Since helium or any other inert gas has very little reactive or thermally stable chemical properties, the membrane may be designed in a material that will depend solely on the chemical properties of the extinguishing agent 6. The membrane also gets rid of any obligation to be refractory or, at least, to have resistance to high temperature rises, as is well known using a pyrotechnic generator releasing a gas at high temperature. This shows an advantage in terms of simplicity of design of the membrane and a decrease in its cost. The deployed membrane may also be designed to burst at the end of expulsion of the extinguishing agent 6, after which a purge of the cavity 1 or of the posterior ducts 7 can be done. This can be done by means of a cutting element at the outlet orifice 5 of the cavity 1. In this case, the deployment membrane 10 is kept away from the opening orifice 5 by means of at least one point of attachment of the deployment membrane 10 disposed at a tolerated distance from the opening orifice 5, which makes it possible to avoid inadvertent sealing of the diaphragm or portions of the membrane in the opening orifice or the outlet pipe 7. Thanks to the arrangement figure 2 , together with the elements secured "lid, tanks, membrane" is still easily removable from the rest of the cavity, for example by unscrewing only the lid of the cavity.

The figure 3 aims to exhibit, among other things, the high modularity and adaptability of the propulsion device according to the invention. The device is here represented in simplified form (cavity 1, extinguishing agent 6, outlet orifice 5) in the case of extinguishing a fire F via nozzles ejection X, Y, Z connected to the outlet 5 of the cavity 1. As for the Figures 1 and 2 , two helium reservoirs 2a, 2b are arranged integrally with the cover (via a holding base 4) inside the cavity 1. For example, the tanks 2a, 2b do not have the same size ( and thus store different amounts of helium) and can be desired to be triggered at various times according to a required pressure profile. In the case of figure 3 it has been imposed to minimize the geometry of the device, for example because of the lack of space to install it in an aircraft. Thanks to the reduction of the helium tanks, at least one other tanks 2c, 2d, 2e is indeed disposed outside the cavity 1 and can be, if possible, fixed on the holding base 4 at the lid 3 (tank 2c, 2d) or directly on cavity 1 (tank 2e). This modularity of the locations of the tanks advantageously makes it possible to reduce the size of the cavity 1 containing the extinguishing agent 6 or to fill the cavity 1 with the extinguishing agent 6 more if necessary. Thus, the device of the present invention can be properly installed in a base-based or complex infrastructure environment. If in addition the problem of space was even more accentuated or even if the tanks were to be removed from the cavity or concealed such as for reasons of safety, it is also possible to remotely connect an external tank to the cavity 1 via a pipe arrival INc ending in the cavity 1 via the cover 3 for example. All these aspects make the device a system adaptable to very diverse situations and always reconfigurable according to the requirements or the modifications of its environment. In the same way as Figures 1 and 2 , some tanks may be used for extra pressure or additional safety purpose compared to other tanks.

Of course, the propulsion device with several helium tanks is combinable with a propulsion device whose initially the pressure generator is of the pyrotechnic generator type. For example, the helium tanks could then act as a backup pressure generator of a pyrotechnic gas generator when the properties or conditions of the extinguishing device are to be readjusted.

In summary, the tanks 2a, 2b,... Can therefore easily be used as substitutes or complements of a conventional hot gas generator, such as a pyrotechnic generator, in particular in the field of aeronautical, land or maritime transport or in a flammable environment.

Claims (24)

1. Propulsion device of an agent (6) contained in a cavity (1) comprising at least a cap (3) and a port able to be opened (5) above a calibrated pressure inside the cavity, for which a pressure generator (2) is fastened to the cap (3) and induces by electrical triggering the propulsion of the agent (6),
   characterized in that

   - the pressure generator (2) comprises at least two containers (2a, 2b, ...) having respectively an exit (s1, s2) ending inside the cavity (1),

   - the two containers (2a, 2b, ...) each release a propulsion gas on the agent (6),

   - at least one of the containers (2a, 2b, ...) is pressurized with, as a propulsion gas, an inert-type gas suited for minimal temperature fluctuations induced in the cavity during a pressure relief of the inert gas from at least one of the containers towards the cavity (1), which inert gas in expansion being the direct mechanical propellant of the agent (6) via the port able to be opened (5).
2. Device according to claim 1, wherein the inert-type gas is helium (He) in gaseous form.
3. Device according to anyone of claims 1 to 2, wherein the pressure generator (2) comprises at least an opening module of the exits (s1, s2) of the containers (2a, 2b), the said opening module capable of comprising at least one pyrotechnic valve with an energy grade minimal and sufficient to trigger the opening of one of the exits (s1, s2).
4. Device according to anyone of the forementioned claims, wherein the containers (2a, 2b, ...) are able to be triggered to expansion by distinct electrical triggerings or/and have a delayed triggering.
5. Device according to anyone of the forementioned claims, wherein the containers (2a, 2b, ...) have a geometry and a disposition suited to maximize the free volume of filling up with the agent (6) in the cavity (1).
6. Device according to anyone of the forementioned claims, wherein the containers (2a, 2b, ...) have different dimensions or/and gas storage capacities.
7. Device according to anyone of the forementioned claims, wherein at least one of the two containers (2a, 2b) is placed in the cavity (1) by means of an upholding mounting (4) fastened on the cap (3).
8. Device according to anyone of the forementioned claims, wherein at least one of the containers (2c, 2d, 2e) is placed out of the cavity (1) and can be fastened on an upholding mounting (4) on the cap (3) or directly on the cavity (1) and able to be connected via an incoming duct (INc).
9. Device according to one of claims 7 or 8, wherein the upholding mounting (4) comprises an axial element (AX) fastened perpendicularly to the cap (3) and anchoring elements (9) of the containers (2a, 2b, ...) placed around the axial element (AX).
10. Device according to claim 9, wherein a measurement sensor (8) of the level of filling up with the agent (6) in the cavity (1) is incorporated on a portion of the axial element (AX).
11. Device according to anyone of the forementioned claims, wherein one of the containers (2a, 2b, ...) is a pressurized container of additional pressure or a safety container in case of failure of one of the other containers.
12. Device according to anyone of the forementioned claims, wherein at least one of the containers (2a, 2b, ...) is interchangeable, in particular by switching of its exit with the exit of one of another of the containers (2a, 2b, ...) or/and refillable with pressurized gas.
13. Device according to anyone of the forementioned claims, wherein the cavity (1) comprises an inlet of filling up with the agent (6), for example via the cap (3).
14. Device according to anyone of the forementioned claims, wherein the exits of containers (2a, 2b, ...) or their endings inside the cavity (1) are placed in an interstice made between the cap (3) and the agent (6).
15. Device according to claim 14, wherein the interstice comprises deflector means (defl) of gas outflows at the exits (s1, s2) of the containers (2a, 2b).
16. Device according to anyone of the forementioned claims, wherein the port able to be opened (5) is a breakage element with a pre-calibrated pressure for its breaking.
17. Device according to anyone of the forementioned claims, wherein at least one of the containers (2a, 2b, ...) in the cavity (1) is placed in a deployment membrane (10) having a closed surface or able to be closed with the cap (3).
18. Device according to claim 17, wherein the deployment membrane (10) is kept away from the breakage port (5) by means of at least one point of fastening of the deployment membrane (10) placed at a tolerated distance from the openable/breakable port (5).
19. Device according to anyone of the forementioned claims, wherein the gas generator comprises several containers (2a, 2b, ...) placed at least on one side of the cap (3), each container being of cylindrical shape with a revolution axis perpendicular to the cap (3) and whereof the total area of their cylindrical sections is smaller than the one of the cap (3).
20. Device according to anyone of the forementioned claims, wherein the agent (6) is an extinguishing agent, such as FK5-5-1-12, or a cooling agent.
21. Use of the propulsion device of an agent according one of the forementioned claims, wherein the containers (2a, 2b, ...) are used as substitutes or complements of a hot gas generator, such as a pyrotechnic generator, in particular in the area of aeronautical, land, ocean-going transports or in a flammable environment.
22. Use according to claim 21, wherein the device installation infrastructure is of reduced size or/and imposes a distribution or/and a geometry of the cavity (1) and of the containers (2a, 2b, ...) specific to the infrastructure.
23. Use according to claim 21 or 22, wherein in case of inopportune triggering of one of the containers (2a, 2b, ...) in the cavity (1), a confinement of the pressure generator (2) in the cavity (1) sealed by the cap (3) is ensured.
24. Control process suited to a maintenance of the propulsion device of an agent according to one of the forementioned claims, wherein:

    - a measurement control of the level of agent (6) inside the cavity (1) is provided by means of an axis (AX) fastened in the cavity,

    - a control of the evacuation of the cavity (1) is provided through a sensor of burst of the breakage disk.

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