Installation for the destruction of an article by explosion

Abstract

Installation for the Destruction of an Article by Explosion The invention relates to an installation (1) for the destruction of an article by explosion, comprising: - an enclosure (3) configured to contain the explosion, comprising two longitudinal ends (31) each equipped with an access door to the interior of the enclosure, and a body (33) extending between the longitudinal ends, and - a shield (5), located inside the enclosure, configured to protect the enclosure from fragments generated during the explosion and defining an internal processing volume (VT) opening onto each longitudinal end, the shield extending along the body, at a distance from the latter, and resting on positioning elements (7) located under the shield so as to provide, between the body and the shield, an accessible circumferential volume (VC) opening onto each longitudinal end. Figure for the abstract: Fig. 1.

Description

Title of the invention: Installation for the destruction of an article by explosion Technical field

[0001] The present disclosure relates to an installation for the destruction of an article by explosion allowing easy cleaning of the explosion residues accumulated during firing, as well as the associated destruction and maintenance processes. Prior art

[0002] The destruction of munitions can be carried out by explosion in an armored chamber, followed by treatment of the gases resulting from the combustion. This destruction can be carried out on an industrial scale in a DaVinch® installation ("Detonation of Ammunition in Vacuum INtegrated CHamber") developed by the company KOBELCO. Chemical shells dating from the First World War can thus be destroyed, for example.

[0003] The DaVinch® installation comprises a chamber, equipped with a single access door, which ensures the confinement of the explosion, and a shield, located inside the chamber, which rests on a floating sheet and protects the chamber from the fragments generated during the explosion. The shield is not watertight and explosion residues (debris and dust) can accumulate between the chamber and the shield until they occupy the entire space. The shield then loses its mobility and risks transmitting the shock wave directly to the chamber, which can permanently damage it.

[0004] In order to prevent the shielding from coming into contact with the chamber in its upper part, it is necessary to extract the shielding after a certain number of shots to examine the elements of the installation and to clean the interior of the chamber. The means deployed are heavy and can implement hydraulic jacks to be positioned in front of the chamber for each maintenance. To begin the extraction of the shielding, it is necessary to apply a force of several tens of tons to counter friction. A significant power reserve is therefore required, especially if possible jamming must be managed.

[0005] The maintenance procedure for the DaVinch® installation is complex and leads to significant operational downtime. It also presents a risk for operators who must comply with strict safety regulations.

[0006] It is therefore desirable to have an installation for destroying an article by explosion for which the maintenance operation is simplified, thus making it possible to reduce the duration of operation stoppages and to increase the destruction rate. Description of the invention

[0007] The present disclosure relates to an installation for the destruction of an article by explosion, comprising: - an enclosure configured to contain the explosion, comprising two longitudinal ends each provided with an access door to the interior of the enclosure, and a body extending between the longitudinal ends, and - a shield, located inside the enclosure, configured to protect the enclosure from fragments generated during the explosion and defining an internal treatment volume opening onto each longitudinal end, the shield extending along the body, at a distance from the latter, and resting on positioning elements located under the shield so as to provide, between the body and the shield, an accessible circumferential volume opening onto each longitudinal end.

[0008] The installation according to the invention has an accessible volume between the shielding and the enclosure extending along the latter and allows easy cleaning, in particular, of the space located below the shielding to evacuate the explosion residues accumulated during firing. The underside of the shielding is in fact raised relative to the enclosure thanks to the positioning elements to allow inspection and the carrying out of this cleaning. A lighting device and tools, such as a scraper or a suction cannula, can be introduced into the accessible volume which allows cleaning to be repeated easily at the desired frequency without having to lift the shielding, unlike the technique of the prior art. In addition, the presence of the access doors on each of the bottoms allows complete cleaning over the entire length, allowing, if desired, intervention at both ends of the enclosure.The risk of damage to the enclosure by transmission of the shock wave during a shot due to a raising of the shielding is thus avoided. Thanks to the invention, the operation of extracting the shielding is necessary only when it must be replaced after having undergone a significant number of shots, and more for cleaning. By way of illustration, the extraction of the shielding in the DaVinch® installation is recommended every 200 shots whereas, in the invention, the shielding can only be extracted after 1500 or 2000 shots, which drastically reduces the handling frequency and therefore the operational stoppages.

[0009] The shielding is open at its ends on the side of each longitudinal bottom, and is therefore without a bottom. This avoids having to clean the space between the bottom of the shielding and the access door which, in the prior art, requires heavy handling techniques. The inventors have noted that the impacts of the explosions essentially riddle the central part of the shielding. The ends of the shielding are generally spared so that the use of a shielding open at both ends provides satisfactory protection in the majority of cases.

[0010] In an exemplary embodiment, the shielding comprises on the side of each bottom Ion- longitudinal a longitudinal end portion extending beyond the body and configured to form a bearing surface for armor moving tooling.

[0011] This feature advantageously makes it easier to handle the shielding when it has to be removed from the enclosure for replacement. The shielding can be removed using a simple, low-power means compared to the hydraulic jacks used in the prior art. This feature also makes it possible to limit the passage of dust into the area between the shielding and the body.

[0012] In an exemplary embodiment, the positioning elements form discontinuous support zones for the shielding.

[0013] This characteristic helps to minimize the support surface of the shielding on the positioning elements and of the latter on the body so as to open the accessible volume and further reduce the trapping of explosion residues.

[0014] In particular, the installation may comprise two rows of positioning elements distributed along a longitudinal axis of the enclosure which may be located on either side of a vertical plane passing through the longitudinal axis of the enclosure, so as to provide between them an accessible longitudinal channel between the shielding and the body which opens onto each longitudinal bottom.

[0015] This feature helps to further reduce the trapping of explosion residues.

[0016] In an exemplary embodiment, the positioning elements have a shape and / or are made of a material that promotes the damping of the shock wave generated on the body during the explosion.

[0017] Such a feature further reduces the risk of damage to the body by transmission of the shock wave.

[0018] The invention also relates to a method for destroying an article using an installation as described above, comprising: - the positioning of the item to be destroyed in the internal processing volume, and - the destruction of the article thus positioned by explosion.

[0019] The invention also relates to a method of maintaining an installation as described above, comprising: - the destruction of a plurality of articles by implementing the method as described above, and - cleaning of explosion residues produced by the items thus destroyed located in the circumferential volume.

[0020] In particular, the maintenance method may further comprise: - positioning the moving tool on the support surfaces, - extracting the shielding from the outside of the enclosure using the removal tool- placement positioned on the support surfaces, and - the introduction of replacement shielding into the enclosure on the positioning elements, after the shielding has been extracted. Brief description of the drawings

[0021] [Fig.l] [Fig.l] represents, schematically and partially, a longitudinal sectional view of an example of installation according to the invention.

[0022] [Fig.2] [Fig.2] represents, schematically and partially, a section transverse according to ILII of the installation of [Fig.l].

[0023] [Fig.3] [Fig.3] represents, in a schematic and partial manner, the elements of po positioning in top view with the shielding removed.

[0024] [Fig.4] [Fig.4] represents, in a schematic and partial manner, an operation of maintenance of the installation of [Fig.l].

[0025] [Fig.5] [Fig.5] represents, in a schematic and partial manner, another operation maintenance of the installation of [Fig.l]. Description of the embodiments

[0026] The invention is now described by means of figures, present for descriptive purposes to illustrate certain embodiments of the invention and which should not be interpreted as limiting the latter.

[0027] The installation 1 of [Fig.l] is intended for the destruction by explosion of an article (not shown in [Fig.l]). The article may be a pyrotechnic, pyrotoxic or toxic article. The article may comprise an explosive material, such as RDX or HMX, or a chemical agent, such as sarin gas, or a combination of an explosive and a chemical agent. The article may be a conventional or chemical munition.

[0028] The installation 1 comprises an enclosure 3 which is configured to contain the explosion in a sealed manner. The enclosure 3 may be made of steel. The enclosure 3 here has a generally cylindrical shape. The enclosure 3 extends along a longitudinal axis X and comprises two longitudinal bottoms 31 each provided with an access door to the interior of the enclosure 3. The enclosure 3 also comprises a cylindrical body 33 connecting the bottoms 31. Each bottom 31 may be placed in an open configuration, allowing for example the introduction of the article to be destroyed or the cleaning of the installation and in a closed configuration to carry out the destruction by explosion.

[0029] The enclosure 3 defines an internal surface 32 which forms an interior volume of the installation 1 and an external surface 34 defining an exterior part thereof.

[0030] The installation 1 further comprises a shield 5 which is located inside the enclosure 3. The shield 5 is configured to resist impacts with the fragments generated during the explosion, and may for example be made of steel. The shield 5 here has a generally cylindrical shape. The shield 5 extends along the body 33, along the X axis. The shield 5 is open at its two longitudinal end portions 51, that is to say that it does not have a bottom. Thus, the shield 5 defines an internal treatment volume VT which opens onto each longitudinal bottom 31. The shield 5 defines an internal surface 53 which delimits the volume VT, and an external surface 55 opposite the internal surface 32 of the enclosure 3. If desired, each bottom 31 can be provided with a shielding sheet 31a, separate from the shield 5, for example fixed by screwing. This constitutes a precaution to avoid any risk of damaging the bottoms 31, although these are generally spared from the impact with the splinters. The shielding sheet 31a is not in contact with the shield 5 and spaced from the latter.In the illustrated example, each end portion 51 extends beyond the body 33 to form a bearing surface SA for a tool for moving the shielding, as will be described in more detail below in connection with [Fig.5].

[0031] The shield 5 rests on projecting positioning elements 7 located under the shield 5, between the body 33 and the shield 5. The elements 7 are here in the form of studs. A particular configuration of elements 7 which can be used in the context of the invention will be described below in connection with FIGS. 2 and 3. The elements 7 are located on the internal surface 32. The elements 7 allow radial positioning of the shield 5 in the body 33. The elements 7 make it possible to space, or raise, the underside of the shield 5 relative to the body 33 so as to provide, between the body 33 and the shield 5, a circumferential volume VC. Unless otherwise stated, the terms "under", "beneath" and "above" refer to the height H of the enclosure 3. The volume VC extends here all around the shielding 5 (360° around the shielding 5). The volume VC may have an annular shape.

[0032] The volume VC opens onto each bottom 31 so as to allow the introduction of tools to clean the explosion residues without having to move the shielding 5, as will be illustrated below in connection with [Fig. 4]. The shielding 5 is at a non-zero distance from the body 33. By way of illustration, a distance d separating the internal surface 32 (or the body 33) from the underside of the shielding 5 may be greater than or equal to 150 mm, for example between 150 mm and 250 mm. This distance d may also be found between the top of the shielding 5 and the body 33. A difference between the space below and above the shielding 5 may be tolerated as long as the shielding does not come into contact with the body 33.

[0033] The shielding 5 is installed in the enclosure 3 in a floating manner and can move slightly relative to the latter due to the existence of the volume VC, and thus avoid direct transmission of the shock wave produced during the explosion. The shielding 5 is not secured to the enclosure 3 but simply placed on the elements 7. In particular, there is no mechanical connecting element securing the shielding 5 to the enclosure 3. A A holding device can nevertheless be added to limit the deposition of the armor 5 in rolling with each shot, for example a notch made in the armor, for example at its upper end, which encloses a relief projecting from the body at the level of the notch.

[0034] According to an advantageous variant, the elements 7 may be made of a material for damping the shock wave generated during the explosion. As an example of a damping material that can be used, a cable damper may be used, in a non-limiting manner.

[0035] The elements 7 may be in the form of elements attached to the internal surface 32 of the enclosure 3. Those skilled in the art will recognize that the fixing of the elements 7 to the enclosure 3 may be carried out in different ways, for example by screwing.

[0036] The installation 1 further comprises an initiator (not shown) capable of triggering the explosion of the article A which constitutes a device known per se.

[0037] The general structure of the installation 1 has just been described and the following will focus on detailing, in connection with figures 2 and 3, an example of a possible configuration for the elements 7.

[0038] The example described here comprises a first row RI of positioning elements at a first angular position, and a second row R2 of positioning elements at a second angular position, offset from the first angular position along a circumferential direction DC of the enclosure 3. The angular positions are marked, along the direction DC, in cross-section relative to the axis X. In each of the rows RI and R2, the elements 7 are arranged along the axis X. The elements 7 form, in each row, discontinuous support zones for the shielding 5. The elements 7 may be distributed regularly within a row RI, R2 as illustrated, but it is not outside the scope of the invention when this is not the case. Figures 2 and 3 illustrate a vertical plane P which passes through the axis X.Unless otherwise stated, the adjective “vertical” designates the direction along the height H of the enclosure 3 which is transverse, for example perpendicular, to the axis X. The plane P contains the height H and the axis X. The plane P may be a plane of symmetry of the enclosure 3 or of the body 33. The first RI and second R2 rows are positioned on either side of the plane P. The first RI and second R2 rows may be substantially symmetrical with respect to the plane P. For example, the angular distance a1, a2 between each of the rows RI, R2 and the plane P may be between 10° and 70°, for example between 20° and 70°. In the example illustrated, the angular distances a1, a2 are substantially equal but it is not outside the scope of the invention when they differ from each other.

[0039] In the example illustrated, the rows RI, R2 define between them under the shielding an accessible longitudinal channel CL through. The longitudinal channel CL extends along of the body 33 and opens onto each of the bottoms 31. Each row RI, R2 is located between the channel CL and a space EA which extends around the shielding 5. The space EA also opens onto each of the bottoms 31. The rows RI, R2 define spaces El between successive elements 7 putting the channel CL and the space EA into communication, thus facilitating cleaning.

[0040] A particular configuration of elements 7 has just been described, but the person skilled in the art will recognize that other solutions are possible, for example with damping elements having the form of longitudinal rails (continuous shielding support zones), and not studs. It would also be possible to use a single row of positioning elements, each having a sufficient circumferential extension to hold the shielding in place. Generally speaking, it will be noted that it is preferable to minimize the support surface of the shielding 5 on the elements 7, themselves on the enclosure 3, so as to keep an accessible volume as open as possible and thus avoid as much as possible the trapping of explosion residues. By way of illustration, between 1 and 50%, for example between 2% and 15%, of the external surface 55 of the shielding 5 may be supported on the elements 7.

[0041] The structure of the installation 1 has just been described in connection with figures 1 to 3. [Fig.4] describes the use of this installation for the destruction of articles, as well as its cleaning.

[0042] An article A to be destroyed, as described above, is initially suspended in the volume VT, inside the shielding 5. One of the access doors is opened to access the volume VT and then closed before proceeding with the explosion, as illustrated in drawing 4A. The initiator triggers the explosion of the article A, shown by the arrow D. The explosion residues RE accumulate in the volume VC, in particular under the shielding 5, as these destructions take place, as illustrated in drawing 4B. The volume VC is then cleaned, for example using a suction cannula CA capable of being introduced into this volume VC and making it possible to suck up the residues RE, as illustrated in drawing 4C. This produces a cleaned installation ready to be reused for the destruction of articles and this without having moved the shielding 5, as illustrated in drawing 4D.

[0043] When a large number of destructions have been carried out, it may be necessary to replace the shielding 5 which has been damaged by the fragments generated during the multiple explosions. This replacement is illustrated in [Fig. 5]. A moving tool (not shown) is positioned on the bearing surfaces SA under the shielding 5 so as to lift it and extract it from the enclosure 3 in the extraction direction E. A replacement shielding 5R is then introduced in the introduction direction I, using the moving tool, and placed on the elements 7. The installation is thus ready to resume the article destruction processes.

[0044] The expression “between ... and ...” must be understood as including the limits.

Claims

Claims

1. Installation (1) for the destruction of an article (A) by explosion, comprising: - an enclosure (3) configured to contain the explosion, comprising two longitudinal bottoms (31) each provided with an access door to the interior of the enclosure, and a body (33) extending between the longitudinal bottoms, and - a shield (5), located inside the enclosure, configured to protect the enclosure from the fragments generated during the explosion and defining an internal treatment volume (VT) opening onto each longitudinal bottom, the shield extending along the body, at a distance from the latter, and resting on positioning elements (7) located under the shield so as to provide, between the body and the shield, an accessible circumferential volume (VC) opening onto each longitudinal bottom.

2. Installation (1) according to claim 1, in which the shielding (5) comprises on the side of each longitudinal bottom (31) a longitudinal end portion (51) extending beyond the body (33) and configured to form a support surface (SA) for a tool for moving the shielding.

3. Installation (1) according to any one of claims 1 or 2, in which the positioning elements (7) form discontinuous support zones for the shielding.

4. Installation (1) according to claim 3, in which the installation comprises two rows (RI; R2) of positioning elements (7) distributed along a longitudinal axis (X) of the enclosure (3) which are located on either side of a vertical plane (P) passing through the longitudinal axis of the enclosure, so as to provide between them a longitudinal channel (CL) accessible between the shielding (5) and the body which opens onto each longitudinal bottom (31).

5. Installation (1) according to any one of claims 1 to 4, in which the positioning elements (7) have a shape and / or are made of a material promoting the damping of the shock wave generated on the body (33) during the explosion.

6. Method for destroying an article (A) using an installation (1) according to any one of claims 1 to 5, comprising: - the positioning of the item to be destroyed in the internal processing volume (VT), and - the destruction of the item thus positioned by explosion.

7. Method for maintaining an installation (1) according to any one of claims 1 to 5, comprising: - the destruction of a plurality of articles (A) by implementing the method according to claim 6, and - the cleaning of the explosion residues (RE) produced by the articles thus destroyed housed in the circumferential volume (VC).

8. Maintenance method according to claim 7 implementing an installation (1) according to claim 2 or according to any one of claims 3 to 5 attached to claim 2, further comprising: - the positioning of the movement tool on the bearing surfaces (SA), - the extraction (E) of the shielding (5) outside the enclosure (3) using the movement tooling positioned on the bearing surfaces, and - the introduction (I) of a replacement shielding (5R) into the enclosure on the positioning elements (7), after the extraction of the shielding.

Images