Avalanche triggering system

Description

[0001] The present invention relates to the field of preventive avalanche triggering and more particularly concerns an avalanche triggering system such as, for example, described in document FR2771168 A.

[0002] Preventive avalanche triggering is primarily aimed at securing ski areas, transport networks, or even homes.

[0003] The snowpack that forms on a slope comprises a series of snow layers deposited one on top of the other by precipitation. These different layers are often made up of different types of snow, resulting in a certain heterogeneity of the snowpack, which is often the cause of avalanches.

[0004] Preventive avalanche triggering involves creating a shock wave over an upper area of ​​the snowpack surface in order to cause a disruption of the snowpack's equilibrium in that area, before the accumulation of snow can cause a destructive natural avalanche.

[0005] Systems and techniques for intentionally triggering avalanches are already known.

[0006] One known technique involves having an operator place explosive charges precisely where the avalanche is to be triggered. This placement can be done either from a helicopter by dropping the charge or from the ground, where the explosive charge can be dropped, slid, or thrown to the appropriate location. In both cases, the charge is generally detonated using a slow-burning fuse or electrically. The risks inherent in this technique are significant. In addition to the risks directly related to handling explosives, the operator must, for the placement of explosive charges directly on the ground, access often steep areas with unstable snowpack.

[0007] To reduce the risks associated with an operator's presence in the firing zone, remote detonation techniques have been implemented. These techniques utilize military weapons such as rocket launchers or mortar launchers to trigger an explosion on-site. This type of device is not compatible with certain regulations, such as French law, which prohibits the storage of primed munitions.

[0008] One way to reduce the risks associated with handling explosives is the use of explosive gases to generate a shock wave to trigger the avalanche.

[0009] Document FR2636729 describes a remote avalanche triggering system that operates without explosives and is known under the trade name Gazex®. Such a system comprises a cannon mounted on a concrete support and including an opening facing the surface of the snowpack, a filling circuit configured to fill the cannon with an explosive gas mixture, and a firing device configured to trigger the explosion of the explosive gas mixture.

[0010] This type of avalanche triggering system includes a gas reserve sufficient for a season, installed in an adjacent technical room, and a remotely controlled ignition device. Thus, this type of avalanche triggering system offers complete autonomy and perfect safety for the operator. Furthermore, the fixed installation of this system guarantees sufficient, repeatable, and long-lasting power for the protection of large avalanche paths.

[0011] The main drawbacks of this type of system are the need for a complex installation requiring significant civil engineering work for the system itself, the adjacent technical room, and the connecting pipes, as well as the need to perform maintenance on-site, which is by definition difficult to access. The present invention aims to overcome these drawbacks.

[0012] The present invention aims to remedy all or part of these drawbacks.

[0013] The technical problem underlying the invention is therefore to provide an avalanche triggering system that is simple and economical in structure, while limiting the risk of injury to an operator.

[0014] To this end, the present invention relates to an avalanche triggering system comprising: a portable unit configured to be carried by an operator, the portable unit comprising a gas storage device configured to store an oxidizing gas and a combustible gas, an explosion unit configured to be launched by the operator and fluidly connected to the portable unit, the explosion unit comprising a flexible casing configured to be at least partially filled with an explosive gas mixture formed from combustible gas and oxidizing gas from the gas storage device, the flexible casing being deformable between a resting configuration in which the flexible casing has a first internal volume and an inflated configuration in which the flexible casing has a second internal volume that is greater than the first internal volume and is less partially filled with the explosive gas mixture,The explosion unit further comprises a firing device configured to trigger the explosion of the explosive gas mixture contained in the flexible casing, and a control unit configured to remotely control the firing device.

[0015] Such a configuration of the avalanche triggering system allows the latter to be transported by an operator and therefore does not require the carrying out of civil engineering operations for the installation on site of the avalanche triggering system, which significantly reduces the costs of using the avalanche triggering system, as well as the visual nuisances on the operating site.

[0016] Moreover, such a configuration of the avalanche triggering system significantly limits the risk of injury to the operator, since on the one hand he does not have to handle explosive charges, and on the other hand the triggering of the firing device can be carried out remotely using the control unit.

[0017] Therefore, the avalanche triggering system according to the present invention has a simple and economical structure, while considerably limiting the risk of injury to an operator.

[0018] The avalanche triggering system may also have one or more of the following characteristics, taken alone or in combination.

[0019] According to one embodiment of the invention, the flexible envelope comprises an envelope chamber configured to contain the explosive gas mixture, and a filling opening leading into the envelope chamber.

[0020] According to one embodiment of the invention, the flexible envelope is inflatable.

[0021] According to one embodiment of the invention, the gas storage device comprises a oxidizing gas tank and a combustible gas tank.

[0022] According to one embodiment of the invention, the oxidizing gas tank and the fuel gas tank are removable.

[0023] According to one embodiment of the invention, the portable unit comprises a fuel gas distribution circuit which is fluidly connected to the fuel gas reservoir, and an oxidizing gas distribution circuit which is fluidly connected to the oxidizing gas reservoir.

[0024] According to one embodiment of the invention, the combustible gas distribution circuit successively comprises a first regulator, a first solenoid valve and a first check valve, and the oxidizing gas distribution circuit successively comprises a second regulator, a second solenoid valve and a check valve.

[0025] According to one embodiment of the invention, the avalanche triggering system comprises a combustible gas supply conduit extending between the portable unit and the explosion unit and configured to fluidly connect the combustible gas distribution circuit to the flexible casing, and an oxidizing gas supply conduit extending between the portable unit and the explosion unit and configured to fluidly connect the oxidizing gas distribution circuit to the flexible casing.

[0026] According to one embodiment of the invention, the portable unit includes a first connection fitting that is configured to be fluidly connected to the fuel gas tank, and a second connection fitting that is configured to be fluidly connected to the oxidizer gas tank, and the explosion unit includes a primary connection fitting that is configured to be fluidly connected to the flexible casing, and a secondary connection fitting that is configured to be fluidly connected to the flexible casing, the fuel gas supply line fluidly connecting the first connection fitting to the primary connection fitting, and the oxidizer gas supply line fluidly connecting the second connection fitting to the secondary connection fitting.

[0027] According to one embodiment of the invention, the avalanche triggering system further comprises a safety device which is configured to prevent ignition of the ignition device if a separation distance separating the explosion unit from the portable unit is less than a predetermined value.

[0028] According to one embodiment of the invention, the safety device comprises a transmitter which is carried by one of the portable unit and the explosion unit, a receiver which is carried by the other of the portable unit and the explosion unit and which is configured to communicate with the transmitter, the safety device being configured to calculate the separation distance separating the transmitter from the receiver and to prevent firing of the firing device if the separation distance is less than the predetermined distance.

[0029] According to one embodiment of the invention, the safety device includes a processing unit configured to calculate the separation distance between the transmitter and the receiver. This processing unit is configured to prevent the firing device from activating if the separation distance is less than a predetermined distance. The processing unit of the safety device may, for example, be the control unit.

[0030] According to one embodiment of the invention, the safety device is a radio frequency measurement system of the ARVA, GPS, or IoT type. The measurement system is, for example, configured to measure the distance between the flexible enclosure and the control unit.

[0031] According to one embodiment of the invention, the control unit is carried by the portable unit.

[0032] According to one embodiment of the invention, the portable unit includes a control console.

[0033] According to one embodiment of the invention, the portable unit includes an electrical energy storage device, such as a rechargeable battery, configured to electrically power the portable unit and the firing device.

[0034] According to one embodiment of the invention, the avalanche triggering system includes an electrical power cable that electrically connects the firing device to the portable unit.

[0035] According to one embodiment of the invention, the avalanche triggering system comprises a connecting cable which extends between the portable unit and the explosion unit and which contains the combustible gas supply conduit, the oxidizing gas supply conduit and the electrical power supply cable.

[0036] According to one embodiment of the invention, the explosion unit comprises combustible dusts which are configured to be received in the flexible envelope.Combustible dusts can, for example, include dusts of agricultural origin, such as starch dust, peanut dust, wood dust, cellulose dust, flour, corn starch and sugar dust, metallic dusts, such as aluminum or magnesium dust, chemical dusts, such as acetylsalicylic acid dust, ascorbic acid dust and 2,6-Di-tert-butylphenol dust, mineral dusts, such as coal or talc dust, or plastic and rubber dusts, such as polyacrylonitrile dust, polycarbonate dust, polyester dust, polyethylene dust, polypropylene dust, polystyrene dust and polyurethane dust.

[0037] According to one embodiment of the invention, the explosion unit comprises an internal housing containing the combustible dust, the explosion unit being configured such that the combustible dust is projected into the flexible envelope by the oxidizing gas and the combustible gas from the gas storage device when the flexible envelope is at least partially filled by the explosive gas mixture.

[0038] According to one embodiment of the invention, the explosion unit comprises a removable cartridge having a receiving housing in which the flexible casing is housed.

[0039] According to one embodiment of the invention, the explosion unit comprises a support part which includes the firing device, the removable cartridge being mounted removably on the launching part.

[0040] According to one embodiment of the invention, the explosion unit includes a gripping handle. The gripping handle is preferably provided on the support part.

[0041] According to one embodiment of the invention, the removable cartridge comprises a cartridge housing and a removable protective cover which at least partially delimit the receiving housing, the protective cover being configured to be ejected from the cartridge housing by the flexible sleeve when the flexible sleeve is deformed in the inflated configuration.

[0042] According to one embodiment of the invention, the flexible envelope is configured to extend at least partially outside the receiving housing when the flexible envelope is in the inflated configuration.

[0043] According to one embodiment of the invention, the removable cartridge includes the internal housing containing the combustible dust.

[0044] According to one embodiment of the invention, the removable cartridge comprises a frangible partition wall that separates the receiving chamber and the internal chamber. The frangible partition wall is configured to rupture when the explosion unit is supplied with oxidizing gas and combustible gas from the gas storage device. The flexible casing is configured to be fluidly connected to the internal chamber when the frangible partition wall is ruptured, thereby allowing combustible dust to be projected into the flexible casing. Advantageously, the frangible partition wall is formed by a frangible separation membrane.

[0045] According to one embodiment of the invention, the frangible separating wall is configured to break when the pressure in the internal housing exceeds a predetermined pressure value.

[0046] According to one embodiment of the invention, the removable cartridge comprises a dust storage portion delimiting the internal housing, the dust storage portion comprising a first tubular end portion which is closed by the frangible separating wall and which is at least partially inserted into the flexible casing, and a second tubular end portion which is opposite the first tubular end portion and which is closed by a frangible sealing wall.

[0047] According to one embodiment of the invention, the explosion unit comprises an internal chamber which is partially delimited by the frangible sealing wall, the explosion unit further comprising a fuel gas supply circuit which opens into the internal chamber and which is configured to be connected to the fuel gas tank, and an oxidizer gas supply circuit which opens into the internal chamber and which is configured to be connected to the oxidizer gas tank.

[0048] According to one embodiment of the invention, the frangible sealing wall is configured to rupture when the explosion unit is supplied with oxidizing gas and combustible gas from the gas storage device. Advantageously, the frangible sealing wall is configured to rupture when the pressure in the internal chamber exceeds a predetermined pressure.

[0049] According to one embodiment of the invention, the oxidizing gas is dioxygen, ozone, hydrogen peroxide, halogens, or any other oxidizing gas.

[0050] According to one embodiment of the invention, the combustible gas is dihydrogen, methane, ethane, propane, butane, pentane, acetylene, or any other combustible gas.

[0051] According to one embodiment of the invention, the ignition device comprises a spark plug. Advantageously, the spark plug is configured to generate a spark capable of igniting the explosive gas mixture.

[0052] According to another embodiment of the invention, the ignition device comprises an electric detonator, a slow-burning fuse, a NONEL® type detonator, a device for generating a naked flame, a preheating candle or any other device enabling the explosion of the explosive gas mixture, and in particular the heating of the explosive gas mixture beyond a predetermined temperature, for example above 450°C.

[0053] According to one embodiment of the invention, the explosion unit is configured to be transported by a drone.

[0054] According to one embodiment of the invention, the explosion unit includes a fastening element configured to removably attach the explosion unit to a drone.

[0055] In any case, the invention will be well understood with the aid of the following description with reference to the attached schematic drawings representing, by way of non-limiting example, one embodiment of this avalanche triggering system. Figure 1 is a schematic view of an avalanche triggering system according to the present invention. Figure 2 is a longitudinal pair view of an explosion unit of the avalanche triggering system of the figure 1 . Figure 3 is a front view of the explosion unit of the figure 2 . Figure 4 is a side view of a portable unit of the avalanche triggering system of the figure 1 .

[0056] THE figures 1 à 4 represent an avalanche triggering system 2 comprising a portable unit 3 configured to be carried by an operator and an explosion unit 4 configured to be launched by the operator.

[0057] The portable unit 3 includes a gas storage device 5 configured to store an oxidizing gas and a fuel gas. The gas storage device more specifically comprises an oxidizing gas reservoir 6, such as an oxidizing gas cylinder, and a fuel gas reservoir 7, such as a fuel gas cylinder. Advantageously, the fuel gas reservoir 6 and the oxidizing gas reservoir 7 are removable to allow for their replacement when empty. The portable unit 3 may, for example, include one or more fastening straps 8 for removably attaching the fuel gas reservoir 6 and the oxidizing gas reservoir 7 to a support body 10 of the portable unit 3.

[0058] The oxidizing gas contained in the oxidizing gas tank 7 can, for example, be dioxygen, ozone, hydrogen peroxide, halogens, or any other oxidizing gas, and the fuel gas contained in the fuel gas tank 6 can, for example, be dihydrogen, methane, ethane, propane, butane, pentane, acetylene, or any other fuel gas.

[0059] The portable unit 3 further comprises a fuel gas distribution circuit 9 which is fluidly connected to the fuel gas reservoir 6, and a combustion gas distribution circuit 11 which is fluidly connected to the combustion gas reservoir 7. Advantageously, the fuel gas distribution circuit 9 comprises successively a first regulator, a first solenoid valve and a first check valve, and the combustion gas distribution circuit 11 comprises successively a second regulator, a second solenoid valve and a check valve.

[0060] The portable unit 3 also includes a first connection fitting 12 which is fluidly connected to the fuel gas distribution circuit 9, and a second connection fitting 13 which is fluidly connected to the oxidizing gas distribution circuit 7.

[0061] As shown on the figure 2 The explosion unit 4 includes a support part 14 equipped with a gripping handle 15. The support part 14 includes a primary connection fitting 16 and a secondary connection fitting 17, and the avalanche triggering system includes a combustible gas supply conduit 18 which extends between the portable unit 3 and the explosion unit 4 and which fluidly connects the first connection fitting 12 to the primary connection fitting 16, and a oxidizing gas supply conduit 19 which extends between the portable unit 3 and the explosion unit 4 and which fluidly connects the second connection fitting 13 to the secondary connection fitting 17.

[0062] The explosion unit 4 further comprises a removable cartridge 21 which is removably mounted on the support part 14, for example by means of a fixing collar 22. The removable cartridge 21 includes in particular a cartridge housing 23 and a removable protective cover 24 which define a receiving housing 25.

[0063] The explosion unit 4 further comprises a flexible casing 26 which is housed in the receiving housing 25 and which is configured to be at least partially filled with an explosive gas mixture consisting of fuel gas and oxidizing gas from the fuel gas tank 6 and the oxidizing gas tank 7 respectively. The flexible casing 26 comprises a casing chamber 27 configured to contain the explosive gas mixture, and a filling opening 28 leading into the casing chamber 27.

[0064] The flexible envelope 26 is particularly deformable between a resting configuration (see the figure 2 ) in which the flexible envelope 26 has a first internal volume and an inflated configuration (see the figure 1 ) wherein the flexible casing 26 has a second internal volume that is larger than the first internal volume and is less partially filled with the explosive gas mixture. Advantageously, the removable protective cover 24 is configured to be ejected from the cartridge housing 23 by the flexible casing 26 when the flexible casing 26 is deformed in the inflated configuration, and the flexible casing 26 is configured to extend at least partially out of the receiving housing 25 when the flexible casing 26 is in the inflated configuration.

[0065] According to one embodiment of the invention, the flexible envelope 26 can, for example, be made of kraft paper and be folded accordion-style when in its resting configuration. According to another embodiment of the invention, the flexible envelope 26 can, for example, be made of flexible plastic and be formed by an inflatable balloon.

[0066] The removable cartridge 21 further includes a dust storage portion 29 which delimits an internal compartment 31 containing combustible dust 32. The combustible dust 32 may, for example, include dust of agricultural origin, such as starch dust, peanut dust, wood dust, cellulose dust, flour, corn starch, and sugar dust. The combustible dust 32 may also, for example, include metallic dust, such as aluminum or magnesium dust, or chemical dust, such as acetylsalicylic acid dust, ascorbic acid dust, and 2,6-Di-tert-butylphenol dust.Combustible dusts 32 may also include mineral dusts, such as coal dust or talc dust, or plastic or rubber dusts, such as polyacrylonitrile dust, polycarbonate dust, polyester dust, polyethylene dust, polypropylene dust, polystyrene dust and polyurethane dust.

[0067] According to the embodiment shown in the figures, the dust storage portion 29 comprises a first tubular end portion 33 which is closed by a frangible separation wall 34 and which is at least partially inserted into the flexible casing 26, and a second tubular end portion 35 which is opposite the first tubular end portion 33 and which is closed by a frangible sealing wall 36. The frangible separation wall 34 is configured to separate the receiving housing 25 and the internal housing 31, and more particularly to fluidly isolate the internal housing 31 from the casing chamber 27 of the flexible casing 26. Advantageously, the frangible separation wall 34 is formed by a frangible separation membrane, and the frangible sealing wall 36 is formed by a frangible sealing membrane.

[0068] According to the embodiment shown in the figures, the support part 14 has a bore 37 in which the second tubular end portion 35 is removably mounted, and the second tubular end portion 35, the frangible sealing wall 36 and the support part 14 define an internal chamber 38. The explosion unit 4 advantageously comprises a fuel gas supply circuit 39 which opens into the internal chamber 38 and which is fluidly connected to the fuel gas supply conduit 18 via the primary connection fitting 16, and an oxidizer gas supply circuit 41 which opens into the internal chamber 38 and which is fluidly connected to the oxidizer gas supply conduit 19 via the secondary connection fitting 17.

[0069] Advantageously, the frangible sealing wall 36 is configured to rupture when the gas pressure in the internal chamber 38 exceeds a predetermined pressure, while the frangible separating wall 34 is configured to rupture when the gas pressure in the internal housing 31 exceeds a predetermined pressure value. In particular, when the explosion unit 4 is supplied with oxidizing gas and combustible gas from the gas storage device 5, the gas pressure in the internal chamber 38 rises until the frangible sealing wall 36 ruptures, and then the gas pressure in the internal housing 31 rises until the frangible separating wall 34 ruptures, resulting in the projection of combustible dust 32 into the flexible casing 26 and allowing the flexible casing 26 to be filled with the gaseous explosive mixture.

[0070] The explosion unit 4 further includes an ignition device 42, which is attached to the support portion 14 and configured to trigger the explosion of the explosive gas mixture contained in the flexible casing 26. According to the embodiment shown in the figures, the ignition device 42 includes a spark plug 43 configured to generate a spark capable of igniting the explosive gas mixture. However, the spark plug 43 could be replaced by any other ignition device capable of igniting the explosive gas mixture.

[0071] The avalanche triggering system 2 further includes a control unit 44 which is configured to remotely control the ignition device 42, and in particular to control the generation of a spark when the ignition device includes the spark plug 43. The control unit 44 is also configured to control the opening and closing of the first and second solenoid valves belonging to the fuel gas distribution circuit 9 and the oxidizer gas distribution circuit 11.

[0072] According to the embodiment shown in the figures, the control unit 44 is carried by the portable unit 3 and includes a microprocessor capable of generating control instructions. Advantageously, the portable unit 3 comprises a control panel 45 equipped with a plurality of control buttons.

[0073] The avalanche triggering system 2 also includes a safety device comprising a transmitter 46 carried by the detonating unit 4, and a receiver 47 carried by the handheld unit 3 and configured to communicate with the transmitter 46. The safety device further includes a processing unit 48, carried, for example, by the handheld unit 3, configured to calculate the separation distance between the transmitter 46 and the receiver 47. The processing unit 48 is specifically configured to prevent the firing device 42 from activating if the separation distance is less than a predetermined distance. The safety device may, for example, be an avalanche transceiver, also known as an avalanche victim detector (AVD). According to one embodiment of the invention, the control unit 44 and the processing unit 48 may be a single microprocessor.

[0074] The presence of such a safety device makes it possible to avoid any triggering of an explosion of the explosive gas mixture if the operator is not located at a minimum distance from the explosion unit, and therefore to greatly limit the risks of injury to the operator.

[0075] The avalanche triggering system 2 further includes an electrical energy storage device 49, such as a rechargeable battery, which is disposed in the portable unit 3 and is configured to electrically power the portable unit 49 and the firing device 42. The avalanche triggering system 2 also includes a power supply cable 51 which electrically connects the firing device 42 to the portable unit 3.

[0076] Advantageously, the avalanche triggering system 2 includes a connecting cable extending between the portable unit 3 and the explosion unit 4 and containing the combustible gas supply conduit 18, the oxidizing gas supply conduit 19 and the electrical supply cable 51.

[0077] The operation of the avalanche triggering system 2 according to the present invention will now be described.

[0078] When an operator wishes to trigger a preventive avalanche, he throws the explosion unit 4, using the gripping handle 15, to the precise location where he wants to trigger the avalanche, he activates a control button on the control panel 45 so that the control unit 44 commands the opening, for a predetermined time, of the first and second solenoid valves of the combustible gas distribution circuit 9 and the oxidizing gas distribution circuit 11. The supply of combustible gas and oxidizing gas to the explosion unit 4 causes successively the rupture of the frangible separation wall 36, the rupture of the frangible sealing wall 34, the projection of combustible dust 32 into the flexible envelope 26 and the filling of the flexible envelope 26 with an explosive gas mixture.When the desired explosive gas mixture is reached, the operator activates a control button on the control panel 45, causing the control unit 44 to activate the firing device 42 and trigger the explosion of the explosive gas mixture. The shock wave generated by the explosion is transmitted to the snowpack, dislodging the snow and triggering a controlled avalanche.

[0079] According to one embodiment of the avalanche triggering system 2, the detonating unit 4 could be configured to be connected to and transported by a drone. In this embodiment, the detonating unit 4 could be provided, instead of or in addition to the gripping handle 15, with a fastening element on the support portion 14 configured to removably attach the support portion 14 to the drone.

[0080] Thus, when an operator wishes to trigger a preventive avalanche using such an avalanche triggering system 2, he attaches the explosion unit 4 to the drone and commands a movement of the drone to the precise location where he wants to trigger the avalanche, then he activates a control button on the control panel 45 so that the control unit 44 commands the opening, for a predetermined time, of the first and second solenoid valves of the fuel gas distribution circuit 9 and the oxidizing gas distribution circuit 11, so as to fill the flexible envelope 26 with an explosive gas mixture.

[0081] When the desired gaseous explosive mixture is reached, the operator activates a control button on the control panel 45 so that the control unit 44 commands the firing device 42 to trigger the explosion of the explosive gaseous mixture.

[0082] However, the operator could also order the filling of the flexible envelope 26 with an explosive gas mixture before attaching the explosion unit 4 to the drone and ordering the drone to move to the precise location where he wants to trigger the avalanche.

[0083] As can be expected, the invention is not limited to the single form of execution of this avalanche triggering system described above by way of example, but on the contrary encompasses all the variant embodiments defined by the subject matter of the annexed claims.

Claims

1. An avalanche triggering system (2) including: - a portable unit (3) configured to be carried by an operator, the portable unit (3) comprising a gas storage device (5) configured to store an oxidizing gas and a combustible gas, - an explosion unit (4) which is configured to be launched by the operator and which is fluidly connected to the portable unit (3), the explosion unit (4) including a flexible envelope (26) which is configured to be at least partially filled with an explosive gas mixture formed by combustible gas and oxidizing gas coming from the gas storage device (5), the flexible envelope (26) being deformable between a rest configuration in which the flexible envelope (26) has a first inner volume and an inflated configuration in which the flexible envelope (26) has a second inner volume which is greater than the first inner volume and is at least partially filled with the explosive gas mixture, the explosion unit (4) further comprising an ignition device (42) which is configured to trigger the explosion of the explosive gas mixture contained in the flexible envelope (26), and - a control unit (44) which is configured to remotely control the ignition device (42).

2. The avalanche triggering system (2) according to claim 1, wherein the gas storage device (5) includes a combustible gas tank (6) and an oxidizing gas tank (7).

3. The avalanche triggering system (2) according to claim 2, wherein the combustible gas tank (6) and the oxidizing gas tank (7) are removable.

4. The avalanche triggering system (2) according to claim 2 or 3, in which the portable unit (3) includes a combustible gas distribution circuit (9) which is fluidly connected to the combustible gas tank (6), and an oxidizing gas distribution circuit (11) which is fluidly connected to the oxidizing gas tank (7).

5. The avalanche triggering system (2) according to claim 4, which includes a combustible gas supply conduit (18) which extends between the portable unit (3) and the explosion unit (4) and which is configured to fluidly connect the combustible gas distribution circuit (9) to the flexible envelope (26), and an oxidizing gas supply conduit (19) which extends between the portable unit (3) and the explosion unit (4) and which is configured to fluidly connect the oxidizing gas distribution circuit (11) to the flexible envelope (26).

6. The avalanche triggering system (2) according to any one of claims 1 to 5, which further includes a safety device which is configured to prevent ignition of the ignition device (42) if a separation distance separating the explosion unit (3) from the portable unit (4) is less than a predetermined value.

7. The avalanche triggering system (2) according to claim 6, wherein the safety device includes a transmitter (46) which is carried by one of the portable unit (3) and the explosion unit (4), a receiver (47) which is carried by the other of the portable unit (3) and the explosion unit (4) and which is configured to communicate with the transmitter (46), the safety device being configured to calculate the separation distance separating the transmitter (46) from the receiver (47) and to prevent an ignition of the ignition device if the separation distance is less than the predetermined distance.

8. The avalanche triggering system (2) according to any one of claims 1 to 7, wherein the explosion unit (4) includes combustible dust (32) which is configured to be received in the flexible envelope (26).

9. The avalanche triggering system (2) according to claim 8, wherein the explosion unit (4) includes an inner housing (31) containing the combustible dust (32), the explosion unit (4) being configured such that the combustible dust (32) is projected into the flexible envelope (26) by the oxidizing gas and the combustible gas coming from the gas storage device (5) when the flexible envelope (26) is at least partially filled with the explosive gas mixture.

10. The avalanche triggering system (2) according to any one of claims 1 to 9, wherein the explosion unit (4) includes a removable cartridge (21) including a receiving housing (25) in which is housed the flexible envelope (26).

11. The avalanche triggering system (2) according to claim 10, wherein the removable cartridge (21) includes a cartridge casing (23) and a removable protective cover (24) which at least partially delimit the receiving housing (25), the removable protective cover (24) being configured to be ejected from the cartridge casing (23) by the flexible envelope (26) when the flexible envelope (26) is deformed into the inflated configuration.

12. The avalanche triggering system (2) according to any one of claims 1 to 11, wherein the control unit (44) is carried by the portable unit (3).

13. The avalanche triggering system (2) according to any one of claims 1 to 12, wherein the portable unit (3) includes an electrical energy storage device (49) configured to electrically power the portable unit (3) and the ignition device (42).

14. The avalanche triggering system (2) according to any one of claims 1 to 13, which includes a power supply cable (51) which electrically connects the ignition device (42) to the portable unit (3).