METHOD AND INSTALLATION FOR EXTRACTING PROPERGOL FROM A PROPELLER

Abstract

The invention relates to a method for extracting propellant (18) from a charged propellant body (12), said charged propellant body (12) comprising an elongated structure (14) with principal axis A, which is an element of revolution about said principal axis (A), and within said structure, the propellant (18) is located. The extraction method consists of using at least one nozzle (24) producing a jet (28) of liquid that erodes the propellant (18), characterized in that the liquid jet (28) is a flat jet and in that the nozzle (24) follows a helical trajectory coaxial with the principal axis A during the extraction of the propellant (18). Figure 2

Description

Title of the invention: METHOD AND INSTALLATION PROPERGOL EXTRACTION FROM A PROPELLER technical field

[0001] The invention proposes a method and an installation for dismantling a propulsion system, in order to extract the propellant from the loaded propulsion system body. PREVIOUS STATE OF THE ART

[0002] In the context of the reprocessing of propulsion systems, whether military or space propulsion systems, recycling of the different components of a propulsion system exists as an alternative to their combustion.

[0003] For this, in particular, it is necessary to separate the propellant from the structure of the propulsion system.

[0004] The propellant thus extracted from the propellant structure is then reprocessed to extract the propellant components, in particular ammonium perchlorate.

[0005] According to a known embodiment, the extraction of the propellant is carried out by cutting the propellant using jets of pressurized liquid.

[0006] The trajectory of these round jets results in a portion of the propellant remaining attached to the structure in the form of propellant teeth.

[0007] Also, the power of the jets is sometimes too great and when the intersection of jets is located near the wall, these jets can impact the structure.

[0008] According to one embodiment, the material of the structure is stainless steel based, which makes it resistant to the impact of jets.

[0009] On the other hand, when the structure is made of composite material, this material can disintegrate under the effect of the liquid jet.

[0010] As a result, the mechanical integrity of the structure is compromised, and it must then be repaired or discarded. Furthermore, the portion of the structure that is disintegrated mixes with the extracted propellant.

[0011] The propellant thus polluted cannot then be reprocessed, it must therefore be eliminated by combustion, with the pieces of structure, thus producing pollution.

[0012] The invention aims to provide a method and installation for propellant extraction which allows the entire propellant to be separated from the structure of the propulsion body, without harming the integrity of the structure. Description of the invention

[0013] The invention relates to a method for extracting propellant from a charged propellant body, said charged propellant body comprising an elongated structure with principal axis A which is an element of revolution about said principal axis A, and within said structure, the propellant is located, the extraction method consisting of using at least one nozzle producing a liquid jet that erodes the propellant, characterized in that the liquid jet is a flat jet and in that the nozzle travels along a helical path coaxial with the main axis A during the extraction of the propellant.

[0014] The use of a flat jet allows the power of the pressurized liquid to be distributed, which limits the risk of damaging the propellant body structure. Furthermore, the fact that the jet is flared allows it to reach virtually the entire internal surface of the structure, in order to remove all the propellant.

[0015] Preferably, the process is implemented in several phases, each consisting of eroding the propellant by the flat jet, over a predefined thickness.

[0016] Preferably, an adjustment of the nozzle position is made between two successive phases, to bring the nozzle closer to the propellant according to a predefined step.

[0017] Preferably, the trajectory followed by the nozzle has a pitch substantially equal to an axial extent along which propellant is eroded by the flat jet.

[0018] The invention also relates to an installation for implementing a method of extracting propellant from a propellant body loaded according to any one of the preceding claims, which includes a support pole which is supplied with pressurized liquid and which is mobile in translation and rotation about its main axis which coincides with a main axis A of the loaded propellant body, at least one nozzle for projecting a jet of liquid which is carried by the support pole, means for supplying said at least one nozzle with pressurized liquid via the support pole, characterized in that said at least one nozzle is designed to project the liquid in a flat jet.

[0019] Preferably, said flat jet is delimited by two straight lines which are intersecting at the level of the nozzle and which delimit a predefined opening angle of the flat jet.

[0020] Preferably, the value of said flat jet opening angle is degrees.

[0021] Preferably, said at least one nozzle is carried by a support arm allowing to achieve an adjustment of the position and orientation of the nozzle relative to the support pole, and which achieves fluidic communication between the nozzle and the support pole.

[0022] Preferably, the installation comprises a plurality of interchangeable support arms which are able to be interchanged between two phases of the process, to modify the position of said nozzle relative to the support pole.

[0023] Preferably, each support arm is capable of pivoting relative to the support pole about an axis orthogonal to the main axis A during a phase of the process. Brief description of the drawings

[0024] [fig. 1] is a schematic representation of a propellant extraction installation according to the invention

[0025] [fig.2] is a schematic representation showing a carriage phase for propellant extraction.

[0026] [fig.3] is a schematic representation of a support pole which carries several liquid projection nozzles.

[0027] [fig.4] is a schematic representation of a support pole showing the Possible placements of a support arm. DETAILED DESCRIPTION OF THE INVENTION

[0028] Figure [1] shows an installation 10 for extracting the propellant contained in a charged propellant body 12.

[0029] The charged propulsion body 12 comprises a structure 14 of main tubular shape of revolution and having a main axis A.

[0030] This structure is open at one of its axial ends 16, the other axial end can be open or closed.

[0031] Propellant 18 is present inside the structure 14 and is fixed to its inner face.

[0032] The installation 10 operates by using one or more jets 28 of pressurized liquid, achieving an abrasion of the propellant 18.

[0033] Preferably, the pressurized liquid is water. Thus, in the following description, water will be used to describe the formation of the jets. It will be understood that other liquids may be considered and that the use of such an alternative liquid will be deduced from the description by analogy.

[0034] The installation 10 includes a support pole 22 which extends coaxially to the main axis A of the structure 14 and which is mobile in rotation around this main axis A and in translation along the main axis A.

[0035] The support pole 22 carries at least one nozzle 24 for projecting pressurized water towards the propellant 18 in the form of a jet 28.

[0036] According to the embodiment shown in [fig.1], the support pole 22 carries two projection nozzles 24 which are distributed on an axial end 22A of the support pole 22.

[0037] It will be understood that the installation 10 is not limited to these embodiments comprising two projection nozzles and that the installation 10 may comprise a single projection nozzle 24 or several nozzles 24 strategically distributed on the support pole 22.

[0038] In the following description, reference will be made to a single projection nozzle 24. It will be understood that the description for an embodiment comprising several projection nozzles 24 can be deduced by analogy.

[0039] The installation 10 also includes a support arm 26 for the nozzle 24, which connects the nozzle 24 to the support pole 22.

[0040] The support arm 26 allows for precise positioning of the nozzle 24 relative to the structure 14 and the propellant 18 to be extracted, i.e. in particular the position relative to the main axis A and the orientation of the nozzle 24.

[0041] The supply of pressurized water to the nozzle 24 is achieved via the support pole 22 and the support arm 26.

[0042] The support pole 22 thus includes internal conduits for circulating pressurized water (not shown) which open into orifices formed in the external wall of the support pole 22.

[0043] The support arm 26 consists of a tubular element, one end of which is connected to the nozzle 24 which it carries and the other end of the support arm is in fluidic communication with the internal conduits of the support pole 22, through an orifice in the support pole 22, at which point the support arm 26 is mounted on the support pole 22.

[0044] The nozzle 24 is designed so that the water jet 28 is flared and flat. The water jet 28 exiting the nozzle 24 is therefore a flat jet.

[0045] More specifically, the water jet 28 is mainly triangular in shape, and it is delimited by two straight lines 30 which are intersecting at a point located in the nozzle 24 and these two straight lines delimit an angle 32, which is the opening angle of the water jet 28.

[0046] Preferably, the value of the opening angle 32 is 10 degrees. It will be understood that the invention is not limited to this single value and that it may also relate to a nozzle 24 producing a water jet 28 for which the value of the opening angle 32 is between 10 and 40 degrees.

[0047] The water jet 28 extends in a plane defined by these two lines 30.

[0048] During the extraction of the propellant 18, the support pole 22 rotates around the axis main axis A and translates along this main axis A. The nozzle 24 thus follows a helical trajectory coaxial with the main axis A.

[0049] Preferably, the support arm 26 of the nozzle 24 is designed so that the plane in which the water jet 28 exiting the nozzle extends is perpendicular to a direction tangential to this helical trajectory.

[0050] Also, according to the embodiment shown in [fig.2], the median axis B of the water jet 28 is inclined with respect to a radial direction with respect to the main axis A, in the direction of the advance direction of the support pole 22 during the extraction of the propellant 18.

[0051] It will be understood that the invention is not limited to this radial orientation of the median axis B and that the median axis B can be inclined differently, in particular, the median axis B can be radial with respect to the principal axis A.

[0052] This is particularly the case when the installation includes several nozzles 24, which are supported by several support arms 26, or even when several nozzles 24 are supported by the same support arm 26.

[0053] A method for extracting the propellant 18 from the loaded propellant body 12 using such an installation 10 consists of using a nozzle 24 producing a flat water jet 28 and making it follow a helical trajectory coaxial with the main axis of the loaded propellant body 12.

[0054] By following this trajectory, the flat water jet 28 erodes part of the propellant 18, over a given thickness 34 and over the entire axial length of the loaded propellant body 12.

[0055] The helical trajectory of the nozzle 24 has an axial pitch which is defined as a function of the axial extent 36 along which propellant is eroded by the water jet 28.

[0056] Preferably, when the installation includes a nozzle 24, the value of the axial pitch is equal to this axial range 36.

[0057] According to one variant, the value of the axial pitch is less than this axial extent 36, in order to have an overlap of the passes of the water jet 28 on the propellant 18.

[0058] When the installation includes several nozzles 24, the value of the axial pitch may be less than this axial range 36.

[0059] The process consists of successively implementing several phases during each of which a part of the propellant 18 is eroded according to said thickness 34, the number of these phases is defined according to the total thickness of propellant 18.

[0060] As previously stated, since the water jet 28 is flared and flat, when it impacts the structure 14, its power makes it possible not to damage the latter, even a structure 14 made of composite material.

[0061] At the beginning of a phase, the nozzle 24 is positioned as close as possible to the propellant 18 to be extracted, in order to ensure optimal efficiency of the water jet 28. This positioning is achieved by choosing a support arm 26 with the appropriate dimensions.

[0062] During each phase, pressurized water is conveyed to the nozzle 24 to form the flat water jet 28.

[0063] At the same time, the support pole is set in motion, i.e. in rotation around the main axis A and in translation along the main axis A, as shown by the arrows 38 in [fig.2], to give the nozzle 24 and the flat water jet 28 a helical trajectory, over the entire axial length of the charged propellant body 12.

[0064] At the end of a phase, part of the propellant 18 was trimmed according to the previously defined erosion thickness 34.

[0065] An adjustment of the position of the nozzle 24 is made between two successive phases, so that the nozzle 24 is again at the best possible distance from the propellant 18 to be extracted for the phase which is going to be implemented.

[0066] This position adjustment consists of replacing the support arm 26 used during one phase with another support arm adapted to position the nozzle 24 for the next phase.

[0067] For example, the support arm 26 used in the later phase has a greater length than the support arm 26 used in the earlier phase.

[0068] According to an alternative embodiment based on [fig.4], the support arm 26 is mounted articulated relative to the axial end 22A of the support pole 22 around a transverse axis perpendicular to the main axis A.

[0069] The support arm 26 is able to pivot around this transverse axis between two extreme positions represented in [fig.4] by dotted lines.

[0070] A first extreme position 26A located in the extension of the axial end 22A of the support pole 22 is inclined 20 degrees below the main axis A, the second extreme position 26B is inclined 155 degrees above the main axis A, i.e. a total angular deflection of 175 degrees.

[0071] Preferably, the arm 26 oscillates relative to the axial end 22A of the support pole 22 during each extraction phase, in addition to the rotation of the support pole 22 around the main axis A and the axial translation of the support pole 22.

[0072] Preferably, for the last phase of the process, the thickness of propellant 18 present on the structure 14 is less than the thickness 34 that the flat water jet 28 can erode. This allows all of the remaining propellant to be extracted.

[0073] Also, even if the flat water jet 28 reaches the wall of the structure 14, it cannot damage it, as previously stated. The structure 14 can then, depending on the circumstances, be reused or reprocessed.

[0074] Also, during all phases of the extraction process, only a mixture of water and propellant is recovered, which facilitates the subsequent reprocessing of the propellant.

Claims

Demands

1.

1. i A method for extracting propellant (18) from a charged propellant body (12), said charged propellant body (12) comprising an elongated structure (14) with principal axis A which is an element of revolution about said principal axis (A), and within said structure, the propellant (18) is located, the extraction method consisting of using at least one nozzle (24) producing a jet (28) of liquid which erodes the propellant (18), in which the jet (28) of liquid is a flat jet and in which the nozzle (24) follows a helical path coaxial with the principal axis A during the extraction of the propellant (18), characterized in that it is carried out in several phases each consisting of eroding the propellant (18) by the flat jet (28), over a predefined thickness (34).

2. 2. Method according to the preceding claim, characterized in that an adjustment of the position of the nozzle 24 is carried out between two successive phases, to bring the nozzle (24) closer to the propellant (18) according to a predefined step.

3. 3. Method according to any one of the preceding claims, characterized in that the trajectory followed by the nozzle (24) has a pitch substantially equal to an axial extent (36) along which propellant is eroded by the flat jet (28).

4. 4. An installation (10) for implementing a method of extracting propellant (18) from a loaded propellant body (12) according to any one of the preceding claims, comprising a support pole (22) supplied with pressurized liquid and movable in translation and rotation about its principal axis which coincides with a principal axis A of the loaded propellant body (12), at least one nozzle (24) for projecting a liquid jet carried by the support pole (22), and means (26) for supplying said at least one nozzle (24) with pressurized liquid via the support pole (22), wherein, during the implementation of said method, the nozzle follows a helical trajectory, characterized in that said at least one nozzle (24) is designed to project the liquid in a flat jet (28) extending in a plane perpendicular to a direction tangential to this helical trajectory.

5. 5. Installation (10) according to the preceding claim, characterized in that said flat jet (28) is delimited by two straight lines (30) which are intersecting at the level of the nozzle (24) and which delimit a predefined opening angle (32) of the flat jet (28).

6. 6. Installation (10) according to the preceding claim, characterized in that the value of said angle (32) of opening of the flat jet (28) is 10 degrees.

7. 7. Installation (10) according to any one of claims 4 to 6, characterized in that said at least one nozzle (24) is carried by a support arm (26) allowing adjustment of the position and orientation of the nozzle (24) relative to the support pole (22), and which provides fluidic communication between the nozzle (24) and the support pole (22).

8. 8. Installation (10) according to the preceding claim, for carrying out a process according to claim 2, characterized in that it comprises a plurality of interchangeable support arms (26) which are capable of being interchanged between two phases of the process, to modify the position of said nozzle (24) relative to the support pole (22).

9. 9. Installation (10) according to claim 7 or 8, characterized in that each support arm (26) is able to pivot relative to the support pole (22) around an axis orthogonal to the main axis (A) during a phase of the process.

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