EP1609507A1 - System to extinguish a fire by injection of a gas generated by the combustion of a pyrotechnical charge - Google Patents

Abstract

The extinguisher (1) consists of a gas generator (2) in the form of a chamber (10) with an outlet (16) and a block of a pyrotechnic material (12) that generates a propellant gas containing at least 20 per cent nitrogen and/or carbon monoxide and/or carbon dioxide. It has a distributor (4) for the generated gas, a gas pressure regulator (20), and a combustion initiator (14) with a controller (22). A variant of the design can have a number of gas generators.

Description

TECHNICAL FIELD AND PRIOR ART

The invention relates to apparatus for controlling against fire, in other words extinguishers. In particular, the invention finds its application in stationary fire suppression devices that can be triggered remotely.

The invention relates more particularly to the generation of an inert gas by combustion of a pyrotechnic composition and the diffusion of this gas in the fire zone with controlled flow; the invention refers to a fire extinguisher including an enclosure of combustion, a regulation system and means of diffusion in the fire zone, in particular used in the field of aeronautics.

STATE OF THE PRIOR ART

Most of the time, the devices extinguishing media include a tank containing a extinguishing agent that is diffused on the fire zone to extinguish it, but also to prevent its extension.

Agent tank extinguishers are classified into two broad categories. The first one category concerns permanent pressure vessels in which a gas provides the pressurization permanent agent within a single bottle serving as a reservoir. The extinguishing agent is released by a valve, at the outlet of said bottle. In the second category, a propellant is released only putting the fire extinguisher into service and propelling the agent extinguisher which is not stored under pressure.

By way of illustration, as fire extinguisher first type, we can consider extinguishers currently used to extinguish an engine fire aircraft. These devices use halon as extinguishing agent, stored in liquid form as a result of level of pressurization of the bottle used as tank. Depending on the security requirements, two extinguishers or more can be installed. One or several distribution pipelines connected to each bottle allow the distribution of the agent towards the area or areas to be protected. At the end bottom of the bottle, a calibrated lid allows to close the distribution pipe for keep the halon in the bottle. A sensor of pressure is also installed in order to check, continuous way, the pressurization of the bottle. When a fire is detected, a pyrotechnic detonator is triggered: the shock wave generated by this detonator comes to pierce the shutter optic, which causes the emptying of the bottle and the evacuation of the extinguishing agent under the effect of pressure towards the areas to be protected via distribution pipelines.

With regard to fire extinguishers second category they use a separate device pressurizing. These devices fight against fire are usually equipped with a first compressed gas tank and a second tank for the extinguishing agent. When the device is used, the gas contained in the first tank is put into communication through an orifice with the second reservoir, which allows the pressurization of the bottle containing the extinguishing agent. Sometimes the first compressed gas tank is replaced by a gas generator as described in the document WO 98/02211. In any case, when the agent extinguisher is pressurized, it is ejected from second class fire extinguishers to fight the fire, as for the appliances of the first category.

The disadvantage of these extinguishers, which whatever category is considered, is the storage in continuous extinguishing agent, with the necessary monitoring and verification operations, such as periodic weighing. For devices used for fire extinguishing on board aircraft, belonging to the first category, are added the imperatives related to the pressure storage of the agent extinguisher, and in particular the problems caused by their sensitivity to micro leaks.

STATEMENT OF THE INVENTION

The object of the invention is to remedy mentioned drawbacks of fire extinguishers, in particular for fires in aircraft engines, among others advantages.

In order to do this, the invention one of its aspects a fire extinguishing device whose extinguishing agent is an inert gas only when necessary, that is to say when the use of the fire extinguisher, by the burning of a pyrotechnic material appropriately selected. We can generate a large amount of inert gas whose composition depends on the nature of the material pyrotechnic; in particular, the gas can understand more than 20% of nitrogen or more than 20% or even 40% of mixture of neutral gases such as nitrogen, monoxide and / or carbon dioxide. Preferably, the inert gas generated will consist essentially of nitrogen considering its relative ease of production by combustion pyrotechnic.

The nitrogen generated is injected into the zones where the fire was detected. To ensure extinction reliable, the inert gas is driven out of the device fire extinguisher according to a regulated pressure, in order to including bringing the amount of oxygen into the areas fire to follow a predetermined profile according to the time, for example a level of concentration almost constant during a non-zero period of time.

The device according to the invention comprises therefore a pyrotechnic gas generator associated with means for distributing the gas generated as an agent fire extinguisher and means to regulate the pressure.

Advantageously, the generator of gas comprises an enclosure comprising a block of propellant and a pyrotechnic igniter. The ignition of the pyrotechnic igniter by electric current allows for example the start of the combustion of the propellant whose decomposition allows the generation an inert gas.

Preferably, the extinguishing device includes filters located in the enclosure of combustion or in the means of distribution, so that soot and ash also produced by the combustion of the pyrotechnic composition do not reach not the fire zone.

Advantageously, the device comprises means for cooling the generated gas.

The extinguishing device may comprise a variable number of gas generators, which are connected to the same distribution means. It is also possible to have multiple materials pyrotechnics of different compositions in a even pregnant.

The regulation means are parameterized way by determining the pressure at which the inert gas is expelled from the enclosure, directly related to the flow of gas ejected on the zone fire and concentration, oxygen or other component, sought in the areas to be treated. next the geometry of the distribution network, the dimensions and the breakdown of the areas to be treated, taking account the pressure losses or the layout of the zones to treat, those skilled in the art can determine the pressure required. These calculations can be refined during experimentation.

According to one embodiment, the means of pressure regulation consist of at least one control valve located in the means of distribution, the opening of which is ordered during the extinguisher trigger sequence, either by an external order, either by putting into the combustion chamber. The control valve is advantageously controlled according to a given law and defined by the user, possibly using information from sensors, which measure for example the concentration of oxygen in the zones treat ; this allows loop regulation closed, even finer, the pressure of the gas.

The opening of the valve can be controlled remotely, by manual control, or by a mechanism control coupled to the firing means of the pyrotechnic composition.

The geometry of the block of material pyrotechnics also makes it possible to generate combustion according to a predetermined law. The means of may also, or alternatively, consist of a determination of the different parameters of the gas generator, and in particular the geometry of the propellant block, which ensures controlled generation of inert gas injected into the areas to be protected.

In this case, it is possible to replace the control valve through a calibrated orifice: a once triggered, burning the block of material pyrotechnics no longer requires a command, and the calibrated orifice makes it possible to control the pressure at which will be the combustion of the propellant so as to ensure the agent flow required for inert gas from the fire zones.

Regulation can also, alternatively or in addition, be provided by other regulating devices such as a regulator whether or not associated with a device that creates a difference pressure (diaphragm, nozzle).

Whatever the means of regulation, they make it possible to optimize the duration during which the inert agent concentration will lead for example to a Oxygen level below 12% in fire zones considered. In this way, it is also possible to create niches of shape concentration variable and precisely control the duration and the level of protection of the area.

In one aspect of the invention, the extinguisher can be triggered by a remote operator. he can also be put into operation directly by a ignition device receiving the information of a sensor that detects conditions related to the probability of a fire. To avoid triggers unwanted, especially during operations maintenance, the device can be equipped with neutralization.

The extinguishing device according to the invention is preferably used in aircraft, especially in turbojets where it allows to get rid of extinguishing agents halogenated currently used.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying figures and drawings will to better understand the invention but are given only as an indication and are in no way restrictive.

FIG. 1 represents a device extinguishing device according to one of the embodiments of the invention.

Figure 2 shows an alternative to extinguishing device according to the invention.

Figure 3 shows another mode of realization of the extinguisher according to the invention.

Figure 4 shows schematically the mounting on board an aircraft of a device extinguishing engine fire according to the invention.

Figures 5 show the curves of evolution of oxygen concentration in two fire zones equipped with the following extinguishing device the invention.

DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS

As shown in Figure 1, the extinguisher or fire extinguisher 1, includes a inert gas generator 2 associated with means of distribution of gas 4. The means of distribution of the gas 4 may consist of driving sufficiently long to reach the fire zone 6, or be coupled to any known dispensing device 8, such as by example a multi-outlet pipe.

The gas generator 2 is constituted by a combustion chamber 10, for example cylindrical, in which is placed a pyrotechnic cartridge 12, usually consisting of propellant. The combustion of propellant, initiated by the ignition device 14, generates an inert gas that flows in the means of distribution 4 by an outlet port 16.

Inert gas, largely composed nitrogen and / or carbon monoxide produced by the decomposition by combustion of compositions pyrotechnics, is at high temperature, and a rapid cooling may be necessary before introduction in the fire zones. Means of cooling can thus be provided, for example an "active" filter, that is to say a chemical compound introduced into or out of the chamber of burning and absorbing some of the heat of combustion, or a metal filter. Moreover, he may be desirable that filters, chemical and / or mechanics, be present to filter the soot.

These different filters 18 can be located upstream and / or downstream of port 16 of leaving the gases, in the enclosure 10 or in the means distribution 4.

Advantageously, the outlet orifice 16 of the combustion chamber 10 can be closed by a closing device 20, in order to isolate the propellant of the external environment as long as its action is not not asked. In particular the device of closure 20 can be a tared operculum, that is to say a membrane that breaks or opens after ignition as soon as the pressure inside the chamber of combustion 10 reaches a certain threshold.

The pressure inside the enclosure 10 is advantageously the atmospheric pressure when the extinguishing device 1 is not used. As soon as the ignition device 14 is triggered, the block of propellant 12 starts to burn and generate a pressure in the enclosure 10. The ignition device 14 may consist of any known device. he can be triggered manually, by direct action on the device 14.

Preferably, the ignition device 14 is triggered remotely via a command line 22, which can be coupled to a unit 24. Advantageously, a signal 26 coming from a fire detector can be used as automatic trigger via the unit 24. In this case of tripping automatic, it may be better to plan a neutralization device 28 of the control means 22. It may also be useful to provide manual release device 30 on the housing of control 24 and / or the ignition device 14.

In order to extinguish the fire, one restricts the oxygen supply in the burned area. effect, the gas generated by the combustion of the block pyrotechnic 12 and ejected by the device distribution 8 allows a decrease in the relative oxygen concentration. It is desirable that the generated gas is inert, but also that it is not not polluting or corrosive, especially in the context of a fire zone 6 located in an aircraft engine. In this In this respect, the gas generated therefore comprises a part of nitrogen, at less 20% or even 40%, obtained by the combustion of a pyrotechnic composition strongly "nitrogenated"; he is also possible to associate nitrogen for example with carbon dioxide to increase concentration in neutral gas injected and reach the desired thresholds.

It is commonly accepted, for example, that below an oxygen concentration of 12%, no fire can survive. It is possible to determine the amount of gas to be injected into the fire zone 6 in order to reach this O _{2 level} ; in case of fire zones ventilation, the rate of air renewal is taken into account when calculating the quantity of gas to be injected. This makes it possible to determine the quantity of pyrotechnic product 12 to be placed in the fire extinguisher under consideration.

In order to optimize the capacities extinguishing it is provided in a fire extinguisher 1 according to the invention a system for regulating the flow of gas in pipe exit 8 in the fire zone 6, that is to say means for regulating the pressure prevailing in the distribution means 4. Thanks to such control pressure, it is possible to minimize the amount of pyrotechnic material 12 and / or the size of the enclosure 10 while making sure that the lights will be off. For example, the means of regulating the pressure make it possible to obtain a predetermined profile of the oxygen concentration in the fire zone, as a bearing for a non-zero time period, or a profile in crenels; it is clear that each of concentrations can have a margin of error per relative to the theoretical fixed value of the bearing. So, a landing can be a "flattened Gaussian", or a curve between two separate values of less than 10% of the value of the bearing.

According to a preferred embodiment, the closing device 20 of the gas generator 2 can to be a control valve, advantageously remotely controlled by first means of control 32. Such control valves are known from, for example, WO 93/25950 or US-A-4,877,051, and commercially available.

The first control means 32 can to be a command line from a unit of command 24, advantageously confused with that which is used to trigger the ignition device 14. Information entered in the control unit 24 allow you to modify, manually or automatically, according to a predetermined sequence or in function of measured parameters, the degree of openness and / or closing the valve 20.

For example, it is possible to provide a sensor measuring the oxygen concentration in the fire zone 6: by the command line 34, the unit 24 can modify the signal sent by the first control means 32 for regulating the opening of the valve 20.

Extinguishing devices 1 according to the invention can be put in parallel and by example be connected to the same device of distribution 8. Another embodiment, presented in Figure 2, relates to the presence of several 2a-2e generators of inert gas within the same extinguishing device 1. The blocks of material pyrotechnic 12a-12e of each of these generators may be of a nature (composition, geometry, that it will be explained later) similar or different. The ignition devices 14a-14e of each of the generators 2a-2e can be triggered independently or simultaneously. Advantageously, control means can trigger selectively combustion and thus optimize the number of generators 2a-2e used according to detection and fire settings, or choose the generator most appropriate if the nature of the propellant blocks 12 is different.

In this embodiment, it is possible that each gas generator 2a, 2b be set in communication with the distribution means 4 by its own duct 4a, 4b provided with its valve regulation 20a, 20b. It is also possible to provide a single valve 20f located on a conduit 4f leading to generators 2c, 2d, 2e coupled together by through conduits 4c, 4d, 4e. In the same way for the embodiment shown in FIG. regulation can be performed in open loop or closed.

Another possibility to realize the regulation of the pressure according to the invention is calibrate the block of pyrotechnic material in order to generate a pressure in the enclosure 10 according to a defined profile. This pressure P (stop pressure) is transmitted directly, and in a parameterized way and controlled, the means of distribution 4 and therefore the fire zone 6.

As it is known for example from the propulsion of rockets, it is indeed possible, in choosing wisely the nature of the propellant and the geometry of the block, to obtain a controlled gas flow generated, and therefore a regulated pressure in the enclosure 10. In this case, even if a control valve 20 can be provided, it is possible to have the combustion chamber 10 and the means of distribution 4 than a simple closure device such as a tared operculum, or even connect directly the outlet orifice 16 to the distribution means 4. A exemplary embodiment of such an extinguishing device is shown in Figure 3.

Advantageously, the outlet orifice 16 is provided with a nozzle 36, shaped if possible of so that the speed of sound is reached at minimum section of the nozzle 36. This allows to isolate the gas generator 2 means of distribution 4; pressure fluctuations in the distribution line 4 do not disturb the combustion of the pyrotechnic material 12, which allows better control of the parameters.

In particular, it is possible to calibrate the block of combustible material 12 so as to obtain a flow of gas leaving the enclosure 10 by the opening 16 equal to a determined value. Ways regulating the pressure, and therefore the agent flow inert in the fire zone 6, are then directly integrated to the gas generator 2: a simple command on the ignition device 14, ensures this flow previously fixed.

Q :

débit (kg/s);

ρ :

masse volumique du propergol (kg/m³) ;

S_c :

surface de combustion du propergol (m²) ;

V_c :

vitesse de combustion du propergol (m/s).

Indeed, mathematical formulas make it possible to link together the various parameters (pressure, speed and combustion surface, flow rate of gas generated, etc.) in order to optimize the geometry of a block of combustible material, of its enclosure. combustion, and the initial conditions for a given pyrotechnic material to achieve the desired inert gas flow. Thus the flow of gas generated by the combustion of a pyrotechnic material 12 such as propellant is: (1) Q = ρ S VS V VS , with:

Q:

flow rate (kg / s);

ρ:

density of the propellant (kg / m ³ );

S _c :

propellant combustion surface (m ² );

V _c :

propellant burning rate (m / s).

It should be noted that the surface S _c depends on the shape of the block; in particular, it can be scalable during combustion.

a,n :

coefficients dépendant de la composition du propergol et déterminés expérimentalement ;

P :

pression d'arrêt (Pa) régnant dans la chambre de combustion 10.

On the other hand, the burning rate of the propellant V _c is a function of the pressure prevailing in the combustion chamber, namely: (2) V VS = aP not , with:

a, n:

coefficients depending on the composition of the propellant and determined experimentally;

P:

stopping pressure (Pa) in the combustion chamber 10.

P :

pression d'arrêt (Pa) ;

A_t :

surface de la tuyère 36 au col (m²) ;

1/C_et :

coefficient de débit (s/m), dépendant de la nature du gaz généré ;

C_d :

coefficient inhérent à la nature de la tuyère.

Finally, the flow of gas passing through a nozzle is expressed by: (3) Q = PA t VS and ·VS d , with

P:

stop pressure (Pa);

At _t :

surface of the nozzle 36 at the neck (m ² );

1 / C _and :

flow coefficient (s / m), depending on the nature of the gas generated;

C _d :

coefficient inherent to the nature of the nozzle.

It suffices to solve these equations according to the intrinsic characteristics of the chosen propellant (ρ, a, n, C _and ) and the desired gas ejection conditions (A _t , P, V _c ) to define the geometry of the gas generator. to ensure the desired flow profile for the required time.

The device according to the invention is particularly suitable for application in aircraft. Figure 4 shows schematically the assembly in a turbine engine 40 of an airplane of a device 1 extinguishing device according to the invention, which can triggered at the fire detection and / or smoke.

Example : Application of the invention to extinguishing engine fire for aircraft.

The generation of inert gas, preferably nitrogen, and more than 20%, or even 30% or 40%, is obtained by the combustion of a pyrotechnic composition "highly nitrogenous". The main characteristics to consider when choosing a pyrotechnic composition are the efficiency in terms of gas production, the density of the material, the combustion temperature and the secondary species generated by the combustion. The toxic or / and corrosive appearance of the fumes must also be taken into account, which leads to the automatic elimination of certain compositions. In particular, a composition recommended in the context of aircraft relates to a mixture of sodium azide and copper oxide (NaN ₃ / CUO) which gives by combustion 40.1% nitrogen. Another possibility relates to guanidine nitrate associated with strontium nitrate (NG / Sr (NO ₃ ) ₂ ) whose combustion gives 32.5% of nitrogen and 20% of carbon dioxide. Also possible is the combination of basic copper nitrate and guanidine nitrate (BCN / NG) to produce a gas containing 24.7% N ₂ and 16.9% CO ₂ .

To evaluate the quantity of nitrogen to be injected, the ventilation rate and the size of the zone (s) concerned are taken into account. By way of example, a motor 40 according to FIG. 4 will be considered with the two fire zones A and B having the following characteristics: Volume
V (m ³ ) Ventilation Q _R (m ³ / s)
(air change rate) Zone A 1,416 0.212 Zone B 0.476 0.285

The inert agent generator is constituted as previously described by a speaker of combustion 10, provided with a block 12 of product pyrotechnics as specified above, of a ignition device 14 and a filter 18, equipped to one end of a nozzle 36 shaped in such a way that the speed of sound is reached at the minimum of section of the nozzle.

• une phase d'extinction E (phase « booster ») : diminution du taux d'oxygène de 21 % (concentration nominale en oxygène de l'air en volume) à 11 % en 1,5 s.
• une phase de maintien M (phase « d'inertage », ou « sustainer ») : maintien de la concentration en oxygène à 11 % pendant 3,5 s.

It is desired that the inerting of the fire zones 6, lasts 5 seconds. Other settings over time are often preferred or even imposed by the regulations, and in this case, we wish:

• an extinction phase E (booster phase): reduction of the oxygen content by 21% (nominal concentration of oxygen in the air by volume) to 11% in 1.5 s.
• a maintenance phase M ("inerting" phase, or "sustainer"): maintaining the oxygen concentration at 11% for 3.5 s.

It can thus be noted that during the phase of M, the flow rate of nitrogen (or inert gas) is lower than during the extinction phase E. Ce two-phase diet can be obtained from various ways like using two compositions different pyrotechnics. Preferably, and as described below, the evolution of the combustion profile of the propellant block (geometric evolution of the surface in combustion) allows to obtain such a regime.

The evolution over time of the oxygen concentration C (t) in a fire zone 6 as shown schematically in FIG. 3 as a function of the fresh air flow rate (air renewal in the zone) Q _R , of the flow from the generator of gas injected into the fire zone Q _I (these two flows being removed from the fire zone 6 by the flow rate Q _S = Q _R + Q _I ), and relative oxygen concentrations C _R and C _I of these two flow rates. input can be expressed by the differential equation: (4) C (t + dt) = C (t) + VS R Q R + C I Q I V dt -C (t). Q S V dt which gives (by definition, the flow of the generator does not contain oxygen and C _I = 0):

In the extinction phase E, it is desired that in a well-defined time (in the 1.5 s example), a concentration of 11% (by volume) of oxygen has been reached. Now, C _R = 0.21, and when t = 0, C (t) = C _R , where k = C _R. (Q _S - Q _R ) / Q _S.

So we have

In the maintenance phase M, it is desired that during a well-defined time (in the 3.5 s example), the oxygen concentration be maintained at a level very close to that reached at the end of the booster phase and below the minimum rate. necessary for combustion. In the same way, C _R = 0.21, and at any time, C _M (t) = C _min = 0.11, where k = C _min - (Q _R .C _R ) / Q _S.

The quantity of inert gas to be injected during this phase is therefore directly obtained: Q _IM = (Q _R / C _min ). (C _R - C _min ) ·

All calculations made, the following values are obtained for the volume flow of inert gas to be injected in the fire zones:

The evolution of oxygen concentration in one point for these two areas fire is shown in Figure 5A for Zone A and Figure 5B for Zone B, where the horizontal line represents the level of oxygen concentration to reach to secure the fire zone considered, ie 12%.

It is clear that he would also possible with a following extinguishing device the invention to manage the flow of inert agent so to have an oxygen concentration in the fire zone evolutionary in a given profile, for example in battlements.

There are many pyrotechnic compositions whose combustion generates a large quantity of inert gas consisting mainly of nitrogen and / or carbon dioxide and / or carbon monoxide, in the example presented 3.16 m ³ , while limiting very strongly the production of undesired additional compounds (see for example above). Those skilled in the art, specialist propellant, will be able to make the most appropriate choice or define new compositions depending on the intended application.

For the example treated here, the design calculations will be carried out with a propellant, chosen solely for illustrative and non-limiting purposes, whose ballistic characteristics are as follows: This = 1034 m / s ρ = 1600 Kg / m 3 a = 1.7.10 -6 n = 0.5 gas yield of gas generated by burnt mass at the combustion temperature: 1.2 l / g.

Moreover, the flow difference between the two phases E and M is in a ratio of 20; gold the outlet orifice 16 (calibrated nozzle 36) of the combustion chamber 10 is identical in both case. The operating pressure P of the generator of gas 10 will therefore, too, evolve in a ratio of 20.

In other words, to avoid going too low in the combustion chamber during the holding phase M, which would be detrimental to the ejection conditions, it is possible to set an operating pressure for this phase, for example 5 bars (5.10 ⁵ Pa). For the extinction phase E, the pressure will then reach 100 bars (100.10 ⁵ Pa).

The volume flow rate that is desired for the booster phase E is Q _I = 1.05 m ³ / s = 1050 l / s, ie a mass flow rate of gas leaving the generator 875 g / s. The burning rate of the propellant at 100 bar is V _cE = aP ⁿ = 1.7.10 ^-6 . (100.10 ⁵ ) ^0.5 = 5.4 × 10 ^-3 m / s.

The thickness of propellant to be burned during this booster phase E of 1.5 s is therefore Ep _E = 8.1 mm. The burning surface S _c is deduced from equation (1), ie S _cE = 0.1 m ² .

The sizing of the nozzle uses equation (3), ie A _t = (Q _Im .C _and ) / (PC _d ), with C _d = 0.99, or a passage area at neck A _t = 91, 4.10 ⁶ m ² , or a diameter d = 10.8 mm.

For the maintenance phase M, the desired volume flow rate is 0.05 m ³ / s or 50 l / s, which gives a mass flow rate of gas leaving the generator Q _Im = 42 g / s for a pressure of 5 bar . The combustion rate is V _cM = aP ⁿ = 1, 2.10 ^-3 m / s, and the thickness of propellant to be burned during this 3.5 s phase is Ep _M = 4.2 mm, ie a surface area of combustion S _cM = 0.022 m ² .

Combustible surfaces, different following the E booster phases and M maintenance (of a ratio of 4.55), can be obtained from several ways, with blocks burning on one side "in cigarette, "on several sides, etc. The shape to to give to the block depends on the conditions of manufacture, the surface evolution, but also the mode of ignition. It is possible to optimize the evolution of the surface of combustion over time to obtain a law of desired flow rate.

As specified above, it is also possible to provide two types of propellants different, for the two phases of combustion.

The description presented above does not exclude not all the alternatives that the person skilled in the art does not will not fail to raise to realize a device according to the invention. In particular, various combinations are possible between the different modes presented. It is clear for example that it is conceivable not to have a box of command 24 but sensors and commands separated for each device to be controlled. Similarly, for a device 1 comprising several generators of gas 2, it is conceivable that certain generators are designed to have a gas production regulated, while others, connected to the same means of distribution, have a generation of gas regulated by 20. Furthermore, according to the profiles searched, it is possible to have more than two different compositions in a propellant block 12.

Claims (21)

An extinguishing device (1) comprising: a gas generator (2) comprising an enclosure (10) provided with a gas outlet (16) and a pyrotechnic material block (12) generating a propellant gas, the generated gas containing at least 20% of nitrogen and / or carbon monoxide and / or carbon dioxide; distribution means (4) of the generated gas coupled to the gas outlet (16); means for regulating (12, 20, 36) the pressure created by the gas generated in the distribution means (4). Device according to claim 1 comprising a plurality of gas generators (2a-2e) each comprising an enclosure (10) provided with an orifice gas outlet (16), a block of material pyrotechnic (12a-12e) propellant generator and connection means (4a-4e) for coupling each gas outlet port (16) to the means for distribution (4). Device according to claim 2 comprising at least one regulating valve (20a, 20b) in the connection means (4a, 4b). Device according to one of Claims 1 to 3 comprising at least one regulation (20, 20f) in the distribution means (4). Device according to one of claims 3 or 4 comprising first means of control (32) capable of controlling the valve of control (20) according to control parameters. Device according to claim 5 in which the first control means (26) include ways to measure concentration of oxygen in the area to be treated and said concentration (36) is one of the control parameters. Device according to one of claims 5 to 6 comprising at least one unit of control (24) connected to the first control means (32). Device according to one of Claims 1 to 7 comprising at least one trigger (14) combustion of at least one block of material pyrotechnic (12). Device according to claim 8 comprising second control means (22) for actuate the combustion trigger (14). Device according to claim 7 comprising at least one combustion trigger of at least least one block of pyrotechnic material and second control means (22) for actuating the combustion trigger (14) connected to the control (24). Device according to one of claim 9 or 10 wherein the second means control means (22) comprise means for detecting a fire, and said detection (34) is one of the control parameters of the trigger (14). Device according to one of Claims 9 to 11 in which the second means control means (22) comprise means for manual trigger, and manual triggering (30) is one of the command parameters. Device according to one of Claims 9 to 12 in which the second means control means (22) comprise means for neutralization (28). Device according to one of claims 1 to 13 wherein the control means are integral with at least one first gas generator (2) and the following parameters of the first generator (2) are selected so that the flow rate of gas (Q) resulting from the combustion of its block of pyrotechnic material (12) in the distribution means (4) follows a predetermined and controlled profile: pressure (P) stop in the chamber (10), size (A) _t ) the orifice (16) and surface (S _c ) of the block of pyrotechnic material (12). Device according to claim 14 comprising a nozzle (36) at the outlet port (16) the enclosure (10) of the first gas generator (2). Device according to claim 15 wherein the nozzle (36) is shaped to at least the nozzle section (36), the gases generated by the combustion of pyrotechnic material (12) of the first generator (2) have an equal speed at the speed of sound. Device according to one of claims 1 to 16 wherein at least one block of pyrotechnic material (12) comprises two different compositions. Device according to one of Claims 1 to 17 comprising at least one operculum calibrated (20) at an outlet (16). Device according to one of Claims 1 to 18, comprising at least one filter (18) particle retention. Device according to one of Claims 1 to 19 including means for cooling (18) the generated gas. Turbojet comprising a device according to one of claims 1 to 20.

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