FR3123013A1 - Projection system for sandblasting device - Google Patents

Abstract

Projection system (40) for sandblasting device comprising: a first sandblasting nozzle (1) comprising a first outlet (11), and configured to project a first sandblasting jet from the first outlet (11), said first sandblasting jet having a component along a longitudinal axis (x) of the projection system (40) in a first sandblasting direction, and a second sandblasting nozzle (2) comprising a second outlet orifice (21), and configured to project a second sandblasting jet from the second outlet orifice (21), the second sandblasting jet having a component along said longitudinal axis (x) of the projection system (40) in a second sandblasting direction, the first direction of sandblasting along the longitudinal axis (x) of the projection system (40) being opposite to the second direction of sandblasting along the longitudinal axis (x). Abstract figure: [Fig.1]

Description

Projection system for sandblasting device

The present invention relates to the field of projection systems for sandblasting device. The projection system of the present invention is intended in particular to be used to sand the walls of hollow bodies, such as metal tubes.

Technology background

Metal tubes are widely used in different areas of the energy industry such as power generation, oil and gas, geothermal, wind, hydrogen, as well as in mechanical engineering or capture and carbon storage. Therefore, these metal tubes are configured to circulate various products. In particular, in order to protect the metal tubes from prolonged contact with these varied products, the internal wall of the tubes, including the threaded portions in the case of a threaded tube, is generally covered by a coating. So that the internal wall of the tubes, including their threaded portions, is correctly and uniformly covered by the coating, it is generally necessary to sandblast the surface of the walls to be coated.

Sandblasting is an industrial technique that allows various surfaces such as steel, stainless steel, cast iron or aluminum to be mechanically stripped or cleaned by the high-speed projection of a sandblasting product.

In order to project a sandblasting product at high speed, the sandblasting devices comprise a pressurized fluid supply, for example air, and a sandblasting product supply. The pressurized fluid supply and the sandblasting product supply are connected to a projection system configured to project a sandblasting jet.

Such a device is for example described in the patent application CN111300286 which discloses a sandblasting device, and more particularly a device for supplying dry abrasive to a sandblasting device.

Patent EP3785851 discloses a sandblasting device. More particularly, EP3785851 describes a sandblasting nozzle in which the sandblasting product is propelled using compressed air. The sandblasting nozzle directs the sandblasting product, propelled by compressed air, onto the objects to be sandblasted. Such a nozzle has the disadvantage of not being practical for insertion into a hollow body, such as a tube, in particular a tube of small diameter such as a sleeve for example. Moreover, even if such a sandblasting nozzle would be inserted into a hollow body, when this hollow body has a threaded portion on its internal surface, a sandblasting nozzle as described in EP3785851 is not practical for effectively sandblasting the portion threaded. Indeed, with such a nozzle it would be necessary to insert it in one direction, then in the other, in order to sand all the loading flanks and all the guide flanks of the threaded portion. Consequently, such a practice inevitably generates long and complex sandblasting operations.

Summary

In order to overcome the drawbacks of the prior art, an idea underlying the present invention is to reduce the complexity and duration of sandblasting operations. More particularly, an idea underlying the invention is to provide a projection system for a sandblasting device which makes it possible to improve the efficiency and uniformity of sandblasting, in particular on a threaded tubular hollow body.

• une première buse de sablage comprenant un premier orifice de sortie, ladite première buse de sablage étant configurée pour projeter un premier jet de sablage depuis le premier orifice de sortie, ledit premier jet de sablage présentant une composante le long d’un axe longitudinal du système de projection selon un premier sens de sablage, et
• une deuxième buse de sablage comprenant un deuxième orifice de sortie, ladite deuxième buse de sablage étant configurée pour projeter un deuxième jet de sablage depuis le deuxième orifice de sortie, ledit deuxième jet de sablage présentant une composante le long dudit axe longitudinal du système de projection selon un deuxième sens de sablage, le premier sens de sablage le long de l’axe longitudinal du système de projection étant opposé au deuxième sens de sablage le long de l’axe longitudinal du système de projection.

According to one embodiment, the invention provides a projection system for a sandblasting device, said projection system comprising:

• a first blast nozzle including a first exit orifice, said first blast nozzle being configured to project a first blast jet from the first exit orifice, said first blast jet having a component along a longitudinal axis of the system of projection according to a first direction of sandblasting, and
• a second blast nozzle including a second exit orifice, said second blast nozzle being configured to project a second blast jet from the second exit orifice, said second blast jet having a component along said longitudinal axis of the blast system according to a second sandblasting direction, the first sandblasting direction along the longitudinal axis of the projection system being opposite to the second sandblasting direction along the longitudinal axis of the projection system.

A sandblast can take a variety of forms. By way of non-limiting examples, a sandblasting jet can have a conical, cylindrical or other shape. In the case of a conical sandblasting jet, the direction of sandblasting is understood by the central axis of the cone formed by the sandblasting jet. In the case of a circular cylindrical sandblasting jet, the direction of sandblasting is for example the center of the circle forming the base of such a circular cylindrical sandblasting jet.

All of these characteristics have the effect that the first nozzle and the second nozzle are oriented so that the first sandblasting jet and the second sandblasting jet are projected in two opposite directions along the same axis. The first sandblasting jet and the second sandblasting jet can be projected simultaneously, on the two opposite sides of the threads of a threaded hollow body, such as a sleeve, into which the projection system is inserted. When a surface has a threaded portion, the two opposite flanks of the threads which form the thread of said threaded portion are commonly called "loading flank" and "guide flank". In other words, the loading flanks and the guide flanks of a threaded portion of a hollow body can be sandblasted simultaneously in a single pass of the projection system. This has the result of significantly increasing the sanding speed of such a hollow body. The complexity and average duration of a sandblasting operation are thus reduced.

According to embodiments, a projection system may include one or more of the following features.

According to one embodiment, the first sandblasting jet has a first sandblasting direction and the second sandblasting jet has a second sandblasting direction, the first sandblasting direction presenting, in projection in a plane comprising the longitudinal axis of the projection and a point of intersection between the first outlet orifice and the first sandblasting direction, a first angle α with the longitudinal axis of the projection system, the second sandblasting direction having, in projection in said plane, a second angle β with the longitudinal axis of the projection system.

A projection system having such a configuration of two sandblasting nozzles makes it possible to limit the shading effect, in particular by adapting the first angle α and the second angle β. Thus, the first angle α can be adapted to the inclination presented by the side intended to be sandblasted by the first sandblasting nozzle of the projection system. In the same way, the second angle β can be adapted to the inclination of the side intended to be sandblasted by the second sandblasting nozzle of the projection system. Such a projection system is therefore particularly suitable for sandblasting a thread whose threads have an angle of inclination of the guide flank different from the angle of inclination of the loading flank, in particular flanks having a negative angle inclination or fillets called dovetail.

Advantageously, the angle α and the angle β are such that:
5° ≤ α ≤ 85° and 5° ≤ β ≤ 85°.

Preferably, the angle α and the angle β are such that:
20° ≤ α ≤ 45° and 20° ≤ β ≤ 45°. Such values for the angle α and the angle β allow a better compromise between the compactness of the spraying system and the quality of sandblasting of the thread flanks.

According to one embodiment, the angle α and the angle β are such that:
5° ≤ α ≤ 10° and 5° ≤ β ≤ 10°. Such values for the angle α and the angle β allow optimum limitation of the size of the projection system. In addition, such values for the angle α and the angle β are particularly suitable for effectively sanding slightly inclined sidewalls, that is to say sidewalls having a low angle inclination, in particular sidewalls having a slight inclination. low negative angle. In a thread, a low angle of inclination for a thread can be understood as an angle of inclination with a value of less than 20°, preferentially less than 15°, ideally less than 8°.

According to one embodiment, the angle α and the angle β are such that:
45° ≤ α ≤ 85° and 45° ≤ β ≤ 85°. Such values for the angle α and the angle β are particularly suitable for threads having flanks having an inclination angle ≥10°.

According to one embodiment, the angle α and the angle β are equal.

According to one embodiment, the angle α and the angle β are such that 34°≤α≤36° and 34°≤β≤36°.

This particular angular arrangement makes it possible to reduce the overall dimensions of the system in a particularly optimal way. Indeed, with such angles, the nozzles do not protrude too much with respect to the longitudinal axis along which they are arranged. The projection system has a small footprint, so it can be inserted into small spaces such as the inside of a tube or a sleeve.

• la première buse de sablage étant fixée à un premier emplacement sur l’élément de support par l’intermédiaire d’un premier moyen de fixation,
• la deuxième buse de sablage étant fixée à un deuxième emplacement sur l’élément de support par l’intermédiaire d’un deuxième moyen de fixation.

According to one embodiment, the projection system further comprises a support element:

• the first sandblasting nozzle being fixed at a first location on the support element via a first fixing means,
• the second blasting nozzle being attached to a second location on the support member via a second attachment means.

According to one embodiment, the first location and the second location on the support element can be separated by a distance of between 1 cm and 80 cm and preferably between 1 cm and 20 cm, ideally between 1 cm and 12 cm.

In one embodiment, the support member defines the longitudinal axis of the projection system. In other words, the longitudinal axis of the projection system is the longitudinal axis of the support element.

The second location to which the second nozzle is fixed via the second fixing means is different from the first location to which the first nozzle is fixed via the first fixing means.

According to one embodiment, the first fixing means comprises a first through hole and having any shape able to be associated with the support element by complementarity.

According to one embodiment, the second fixing means comprises a second through hole and having any shape able to be associated with the support element by complementarity.

The first attachment means and the second attachment means may be referred to as "nozzle supports" in common trade parlance.

The support element can take several forms. According to one embodiment, the support element can be a bar, for example a metal bar, or any other suitable support element. For example, the support element may comprise a plurality of bars, for example a plurality of metal bars or metal rods.

According to one embodiment, the support element is slidably mounted on the first fixing means via a first hole arranged in said first fixing means, and the support element is slidably mounted on the second means fixing via a second hole provided in said second fixing means.

• une barre passant dans le trou du premier moyen de fixation et dans le trou du deuxième moyen de fixation,
• au moins deux barres passant dans le trou du premier moyen de fixation et dans le trou du deuxième moyen de fixation. L’élément de support est donc constitué de plusieurs barres passant toutes dans le même trou de chacun des éléments de support. Les barres peuvent alors présenter une section de dimensions inférieures aux dimensions de la section d’une barre.
• au moins deux barres, chacune des au moins deux barres passant par un trou distinct d’un même moyen de fixation. L’élément de support est donc constitué de plusieurs barres, et chacun des deux moyens de fixation comprend un nombre de trou(s) égal au nombre de barres constituant l’élément de support. Plus il y a de barres, plus le support est rigide, ce qui permet de mieux résister au recul et aux vibrations continues qui ont tendance à déformer l’élément de support lorsque les buses projettent des jets de sablage.

The support element, the first fixing means, and the second fixing means are assembled by clamping elements. The clamping elements can be configured to be screwed into threads made on the wall of holes provided in the fastening means. According to one embodiment, the clamping elements can be screws and nuts. By way of example, the support element may be one of the following:

• a bar passing through the hole in the first fastening means and through the hole in the second fastening means,
• at least two bars passing through the hole of the first fastening means and into the hole of the second fastening means. The support element therefore consists of several bars all passing through the same hole in each of the support elements. The bars can then have a section of dimensions smaller than the dimensions of the section of a bar.
• at least two bars, each of the at least two bars passing through a separate hole in the same fastening means. The support element therefore consists of several bars, and each of the two fixing means comprises a number of hole(s) equal to the number of bars constituting the support element. The more bars, the more rigid the support, which better resists recoil and continuous vibrations which tend to deform the support element when the nozzles project sandblasting jets.

Thanks to these characteristics, the nozzles are removable on the projection system.

When the nozzles used have a projection orientation of the fixed sandblasting jet with respect to the structure of said nozzles, for example if they are manufactured in one piece, the sandblasting jets generated by such nozzles are therefore not modifiable on the nozzles . Also, when the angle α and/or the angle β must be modified in the projection system, it is possible to replace the nozzles with other nozzles having a projection orientation of the sandblasting jet configured to generate jets of sandblasting with different angles α and angle β when mounted on the projection system. Thus, such removable nozzles can be replaced by other nozzles, for example to adapt the projection system to a particular thread or to a narrower hollow body, such as a sleeve.

According to one embodiment, in a second plane, said second plane being perpendicular to the longitudinal axis of the projection system, a projection of the first sandblasting direction and a projection of the second sandblasting direction form an angle ϒ.

Thanks to the presence of the angle ϒ, the two sandblasting jets are sufficiently distant from each other to significantly reduce their interference with each other, or even to eliminate these interferences, when using the projection system. Thus, the effectiveness of a sandblasting jet is not diminished by its interference with the other sandblasting jet. This has the effect of further improving the efficiency and uniformity of sandblasting. In particular, this can make it possible to avoid performing sanding several times on the same area to be sanded, which helps to reduce the duration of a sanding operation.

According to one embodiment, the nozzles can be mounted on the mobile support element in rotation around the longitudinal axis of the support element. For example, by loosening the bar(s) at the fixing means, it is possible to rotate any of the fixing means around the support element so as to modify the angle ϒ.

Preferably, the angle ϒ is such that 10°≤ϒ≤180°.

When ϒ=180°, the nozzles project their respective sandblasting jet onto opposite walls of the same hollow body. The advantage of such a configuration is that it makes it possible to reduce the recoil of the projection system during a sandblasting operation because the two nozzles exert recoil forces in opposite directions to each other, in such a way so that the recoil of one at least partially compensates for the recoil of the other. A value greater than or equal to 10° for the angle ϒ makes it possible to ensure sufficient separation between the first sandblasting jet and the second sandblasting jet to obtain two sandblasting jets which do not interfere with each other during use. blasting system, as such interference decreases blasting efficiency and uniformity.

Still more preferably, ϒ≤50°. In fact, a value of the angle ϒ less than or equal to 50° makes it possible to ensure optimum sanding uniformity.

Preferably ϒ≥15°, even more preferably ϒ≥20°.

Ideally, the angle ϒ is such that: 10° ≤ ϒ ≤ 50°. Even more ideally, the angle ϒ is such that: 20° ≤ ϒ ≤ 50°.

The projection system of the present invention is suitable for sandblasting hollow bodies of small section, such as small diameter metal tubes, for example sleeves. Furthermore, the spraying system of the present invention is particularly suitable for sandblasting threaded portions, in particular threaded portions of metal tubes.

Finally, in the context of the present invention, the sandblasting product can be grains of sand originating from various natural minerals or glass microbeads. As sand is no longer or little used, sandblasting abrasives are now mainly used, the choice of which depends on the task to be performed. Abrasives commonly used to sand the walls of metal tubes used in various fields of the energy industry are, for example: alumina oxides of the brown corundum or bauxite type, silicon carbides, steel shot, cast iron or glass, or mixtures of fluids and boron carbide.

Brief description of figures

The invention will be better understood, and other objects, details, characteristics and advantages thereof will appear more clearly during the following description of several particular embodiments of the invention.

It should be understood, however, that the present application is not limited to the precise arrangements, structures, characteristics, embodiments and appearance indicated. The drawings are not drawn to scale and are not intended to limit the scope of the claims to the embodiment(s) shown in these drawings.

Therefore, it should be understood that when features mentioned in the claims are followed by references, said references are included only to improve the understanding of the claims and in no way limit the scope of the latter.

The is a sectional view of a projection system according to one embodiment of the invention inserted into a hollow tube whose internal wall is to be sandblasted.

The is a three-dimensional diagram of the projection system of the further illustrating a support member and securing means.

The is a three-dimensional diagram of the projection system of the further illustrating a support member and securing means.

The is a three-dimensional diagram of a top view of a projection system as shown schematically in Figures 1, 2a and 2b inserted into a hollow tube whose wall is to be sandblasted and in which the support element is not shown .

The is a three-dimensional diagram of the projection system of the connected to its power supplies.

The is a diagram of a sectional view of a projection system 40 according to one embodiment of the invention inserted into a tube 100 whose internal wall is to be sandblasted.

The tube 100 is a hollow tube that has an internal thread (not shown) intended to be sandblasted using the blasting system 40. The thread of the tube 100 has threads that include a loading flank and a guiding flank. The loading flank and the guiding flank are inclined in opposite orientations.

The projection system 40 comprises a first sandblasting nozzle 1, a second sandblasting nozzle 2 and a longitudinal axis x.

The first sandblasting nozzle 1 comprises a first outlet orifice 11, a first inlet 12, and a second inlet 13 (shown on the ).

The first input 12 can be connected to a first supply of sandblasting product 50 (shown on the ). The first supply of sandblasting product 50 may comprise a supply pipe, for example a hose intended to bring the sandblasting product to the first inlet 12.

The second inlet 13 can be connected to a first pressurized fluid supply (not shown). The fluid under pressure can be air, for example compressed air. The first pressurized fluid supply may comprise a supply pipe, for example a hose, intended to bring the pressurized fluid to the second inlet 13.

In this way, the first sandblasting nozzle 1 is configured to project a first sandblasting jet from the first sandblasting orifice 11. The first sandblasting jet is projected in a first sandblasting direction A.

The first sandblasting direction A forms, in projection in a plane comprising the longitudinal axis x of the projection system 40 and a point of intersection between the first outlet orifice 11 and the first sandblasting direction A, a first angle α with the longitudinal axis x of the projection system 40. Such an orientation of the first sandblasting direction A makes it possible to sandblast the thread of the tube 100 on the side of the side intended to be sandblasted by the first sandblasting nozzle 1 of the projection system 40. The first angle α is adapted to the inclination presented by the side intended to be sandblasted by the first sandblasting nozzle 1. The first angle α can be between 5° and 85°. The angle α is 35° in the embodiment illustrated in the .

The second nozzle 2 comprises a second outlet orifice 21, a third inlet 22 and a fourth inlet 23.

The third input 22 can be connected to a second supply of sandblasting product 51 (shown on the ). The second supply of sandblasting product 51 can comprise a supply pipe, for example a hose intended to bring the sandblasting product to the third inlet 22. The first inlet 12 and the third inlet 22 can also be connected to a one and the same supply of sandblasting product.

The fourth inlet 23 can be connected to a second pressurized fluid supply 52 (shown on the ). The pressurized fluid can be air, for example compressed air. The second pressurized fluid supply 52 may comprise a supply pipe, for example a hose, intended to bring the pressurized fluid to the fourth inlet 23. The second inlet 13 and the fourth inlet 23 can also be connected to one and the same pressurized fluid supply.

In this way, the second sandblasting nozzle 2 is configured to project a second sandblasting jet from the second outlet orifice 21. The second sandblasting jet is projected in a second sandblasting direction B.

The second sandblasting direction B forms, in projection in a plane comprising the longitudinal axis x of the projection system 40 and a point of intersection between the first outlet orifice 21 and the first sandblasting direction A, a second angle β with the longitudinal axis x of the projection system 40. Such an orientation of the second sandblasting direction B makes it possible to sand the thread of the tube 100 on the side of the side intended to be sandblasted by the second sandblasting nozzle 2 of the projection system 40. The second angle β is adapted to the inclination presented by the side intended to be sandblasted by the second sandblasting nozzle 2. The second angle β can be between 5° and 85°. The angle β is 35° in the embodiment illustrated in the .

The first sandblasting nozzle 1 and the second sandblasting nozzle 2 are therefore inclined according to the inclination of the flanks of the threads of the thread of the tube 100. Thus, the projection system 40 makes it possible to sandblast in a single pass the opposite flanks of the threading of the tube 100. For example, the first nozzle 1 can sand the guide flanks and the second nozzle 2 can sand the loading flanks. Such a configuration of the sandblasting nozzles thus makes it possible to sandblast the internal thread of the tube 100 more quickly and more efficiently.

Figures 2a and 2b are three-dimensional diagrams of the projection system 40 of the further illustrating a support member 30 and securing means 31 and 32.

The support element 30 can take several forms. In the embodiment illustrated in FIGS. 2a and 2b, the support element 30 is a circular cylindrical bar whose axis of revolution coincides with the longitudinal axis x of the projection system 40. The circular cylindrical bar can by example be a metal bar or a threaded metal rod.

The first fixing means 31 comprises a first cylindrical through hole 33 arranged in a thickness of the first fixing means 31 along the longitudinal axis x of the projection system 40. On the , it can also be seen that the first fixing means 31 further comprises a first location 35 configured to receive the first input 12 of the projection system 40, and a second location 37 configured to receive the second input 13 of the projection system 40. The first sandblasting nozzle 1 can be fixed in different ways in the first fixing means 31, for example by pressure olive or by clipping the first inlet 12 into the first location 35 and, by pressure olive or by clipping the second entry 13 in the second slot 37.

The second fixing means 32 comprises a second cylindrical through hole 34 arranged in a thickness of the second fixing means 32 along the longitudinal axis x of the projection system 40. On the , it can also be seen that the second fixing means 32 further comprises a third location 36 configured to receive the third input 22 of the projection system 40, and a fourth location 38 configured to receive the fourth input 23 of the projection system 40. The second sandblasting nozzle 2 can be fixed in different ways in the second fixing means 32, for example by pressure olive or by clipping the third inlet 22 into the third location 36 and, by pressure olive or by clipping the fourth entry 23 in fourth slot 38.

In the projection system 40 illustrated in Figures 2a and 2b, the first location 35, the second location 37, the third location 36 and the fourth location 38 are clamps configured to be closed by a screw-nut system ( not shown).

The first fixing means 31 is slidably mounted on the support element 30 via the first hole 33. The second fixing means 32 is slidably mounted on the support element 30 via the second hole 34. Thus, the fixing means 31 and 32 are, on the one hand, mobile in translation along the support element 30, and on the other hand, mobile in rotation around the support element 30. In addition, the fixing means 31 and 32 are even removable on the support element 30.

The first sandblasting nozzle 1 is fixed to a first location on the support element 30 via the first fixing means 31. The second sandblasting nozzle 2 is fixed to a second location, different from the first location, on the support element 30 via the second fixing means 32.

The first location and the second location may be separated by a distance of between 1 cm and 80 cm, preferably between 1 cm and 20 cm, and ideally between 1 cm and 12 cm, measured along the longitudinal axis x of the projection system 40. In the embodiment illustrated in Figures 2a and 2b, the distance between the first location and the second location is 12 cm, measured along the longitudinal axis x of the projection system 40.

The fixing means 31 and 32 used in the present invention to fix the sandblasting nozzles 1 and 2 to the support element 30 can be any type of fixing means known to those skilled in the art and suitable for a sandblasting nozzle can be attached to it. Thus, each sandblasting nozzle can be fixed to its fixing means, for example, by clipping, by clamping or by screwing. Consequently, the sandblasting nozzles 1 and 2 are removable on the fixing means 31 and 32.

The first sandblasting nozzle 1 and the second sandblasting nozzle 2 are therefore movable and removable on the projection system 40. Thus, when the nozzles which are used have a fixed orientation, for example if they are manufactured in one piece, the sandblasting jets generated by these nozzles cannot be modified on the nozzles so that, to modify the angle α and/or the angle β in the projection system 40, it is therefore possible to replace the nozzles with other nozzles having been configured to generate sandblasting jets with a different angle α and an angle β when they are mounted on the projection system 40. Thus, such removable nozzles can be replaced by other nozzles, for example for adapt the projection system 40 to a particular thread or to a narrower hollow body, such as a sleeve.

The is a three-dimensional diagram of a top view of a projection system 40 as shown schematically in Figures 1, 2a and 2b inserted into a tube 100 whose wall is to be sandblasted.

A projection of the first sandblasting direction A and a projection of the second sandblasting direction B in the same plane, said plane being perpendicular to the longitudinal axis x of the projection system 40, form an angle ϒ. The angle ϒ can be between 10° and 180°. In the embodiment illustrated in , the angle ϒ has a value of 20°. The presence of the angle ϒ makes it possible to generate an angular spacing between the first sandblasting jet and the second sandblasting jet, as a function of an angular spacing between the first sandblasting direction A and the second sandblasting direction B in rotation around of the support element 30, that is to say in rotation around the longitudinal axis x on the . The advantage of such a configuration is that the two sandblasting jets are far enough apart to significantly reduce their interference with each other, or even to eliminate this interference, when using the projection system 40. Thus, the effectiveness of a sandblasting jet is not reduced by its interference with the other sandblasting jet. This has the effect of further improving the efficiency and uniformity of sandblasting. A sandblasting operation can thus be carried out very quickly.

The is a three-dimensional diagram of the projection system 40 of the connected to its power supplies 50, 51 and 52. The shows the first input 12 connected to a first supply of sandblasting product 50, the third input 22 connected to a second supply of sandblasting product 51, and the fourth input 23 connected to a first supply of pressurized fluid 52. The second input 13 and a second pressurized fluid supply to which it is connected are not shown. The power supplies 50, 51 and 52 can be held in the fixing means 31 and 32 by any suitable means known to those skilled in the art, for example by clipping, by clamping or by screwing according to the same mechanisms as those used to hold the nozzles 1 and 2 to the fixing means 31 and 32.

Claims (10)

Projection system (40) for a sandblasting device, said projection system (40) comprising:

• a first blasting nozzle (1) comprising a first outlet orifice (11), said first blasting nozzle (1) being configured to project a first blasting jet from the first outlet orifice (11), said first blasting jet having a component along a longitudinal axis (x) of the projection system (40) according to a first direction of sandblasting, and
• a second blast nozzle (2) comprising a second outlet (21), said second blast nozzle (2) being configured to project a second blast jet from the second outlet (21), said second blast jet having a component along said longitudinal axis (x) of the projection system (40) according to a second direction of sandblasting,
  the first blasting direction along the longitudinal axis (x) of the blasting system (40) being opposite the second blasting direction along the longitudinal axis (x) of the blasting system (40).

Blasting system (40) according to claim 1, in which the first sandblasting jet has a first sandblasting direction and the second sandblasting jet has a second sandblasting direction, the first sandblasting direction presenting, in projection in a plane comprising the longitudinal axis (x) of the blasting system (40) and a point of intersection between the first outlet orifice (11) and the first blasting direction, a first angle (α) with the longitudinal axis (x) of the projection system (40), the second sandblasting direction presenting, in projection in said plane, a second angle (β) with the longitudinal axis (x) of the projection system (40). Projection system (40) according to Claim 2, in which the angle (α) and the angle (β) are such that: 5° ≤ α ≤ 85° and 5° ≤ β ≤ 85°. A projection system (40) according to any of claims 2 and 3, wherein the angle (α) and the angle (β) are equal. Projection system (40) according to any one of Claims 2 to 4, in which the angle (α) and the angle (β) are such that α=35° and β=35°. A projection system (40) according to any preceding claim, said projection system (40) further comprising a support member (30):

• the first sandblasting nozzle (1) being fixed at a first location on the support element (30) via a first fixing means (31),
• the second blasting nozzle (2) being fixed at a second location on the support element (30) via a second fixing means (32).

Projection system (40) according to Claim 6, in which the support element (30) is slidably mounted on the first fixing means (31) via a first hole (33) provided in the said first means. (31), and the support element (30) is slidably mounted on the second fixing means (32) via a second hole (34) provided in said second fixing means (32). A projection system (40) according to any preceding claim, wherein in a second plane, said second plane being perpendicular to the longitudinal axis (x) of the projection system (40), a projection from the first direction (A) and a projection of the second direction of sandblasting (B) form an angle (ϒ). Projection system (40) according to claim 8, in which the angle (ϒ) is such that: 10°≤ ϒ ≤180°. Projection system (40) according to any one of claims 8 and 9, in which the angle (ϒ) is such that: 10° ≤ ϒ ≤ 50°.