EP3383145B1 - Plasma torch - Google Patents

Plasma torch Download PDF

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Publication number
EP3383145B1
EP3383145B1 EP18162465.1A EP18162465A EP3383145B1 EP 3383145 B1 EP3383145 B1 EP 3383145B1 EP 18162465 A EP18162465 A EP 18162465A EP 3383145 B1 EP3383145 B1 EP 3383145B1
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EP
European Patent Office
Prior art keywords
torch
plasma
anode
cathode
chamber
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EP18162465.1A
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German (de)
French (fr)
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EP3383145A1 (en
Inventor
Bruno VAN OOTEGEM
Maxime Labrot
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ArianeGroup SAS
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ArianeGroup SAS
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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
    • H05H1/00—Generating plasma; Handling plasma
    • H05H1/24—Generating plasma
    • H05H1/26—Plasma torches
    • H05H1/32—Plasma torches using an arc
    • H05H1/34—Details, e.g. electrodes, nozzles
    • H05H1/40—Details, e.g. electrodes, nozzles using applied magnetic fields, e.g. for focusing or rotating the arc
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
    • H05H1/00—Generating plasma; Handling plasma
    • H05H1/24—Generating plasma
    • H05H1/26—Plasma torches
    • H05H1/32—Plasma torches using an arc
    • H05H1/34—Details, e.g. electrodes, nozzles
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
    • H05H1/00—Generating plasma; Handling plasma
    • H05H1/24—Generating plasma
    • H05H1/26—Plasma torches
    • H05H1/32—Plasma torches using an arc
    • H05H1/34—Details, e.g. electrodes, nozzles
    • H05H1/3452—Supplementary electrodes between cathode and anode, e.g. cascade

Definitions

  • the invention relates to a plasma torch comprising an anode and a cathode each provided with a coil for generating a magnetic field.
  • the anode and cathode of the torch according to the invention have an increased life.
  • Plasma torches are equipment that began to appear in the early 1930s with the development of electricity for an industrial purpose.
  • the real development of these systems in the industrial world is effective since the 1970s, we find these systems in the iron and steel industry as well as process chemistry.
  • FIG. 1 a basic model of a torch 200 for generating a plasma according to the prior art.
  • This torch 200 comprises a metal anode 202 in the form of a tip and a cathode 204 in the form of a cone.
  • An electric arc A is established between the anode 202 and the cathode 204.
  • a gas is injected between the two electrodes (arrows 208) in order to form the FP plasma stream.
  • a first problem of this type of plasma torch is related to the erosion of the electrodes 202 and 204 produced by the arc A which affects the life of the latter.
  • An additional limitation related to this reduced electrode life in the prior art is that only neutral or non-oxidizing gases can be used to generate the plasma. In fact, the atomic oxygen generated in a plasma degrades the electrodes even more rapidly.
  • neutral gases, such as helium can be expensive, thus helping to make relatively high the cost of implementation torches of the prior art.
  • a second problem that can be encountered with the prior art plasma torches is that the arc A is free to hang on at any position of the cathode 204. This free positioning of the arc generates a fluctuation of its length in time. The length of the arc being directly representative of the voltage of the arc, this results in a significant fluctuation of the voltage, and therefore of the power.
  • the invention proposes, according to a first aspect, a plasma torch according to claim 1.
  • the first and second coils can generate an induced magnetic field generating a force for rotating the electric arc formed between the anode and the cathode.
  • This rotation of the electric arc makes it possible to distribute the erosion of the electrodes on the external surface of the body and, consequently, to increase the lifetime of the electrodes.
  • each conductive body has an internal surface in communication with a coolant introduction orifice.
  • each conductive body has a toric shape.
  • each of the first and second coils is carried by a coil carrier having a toroidal shape.
  • the torch comprises a single cathode and a single anode.
  • each conductive body is made of copper or copper alloy.
  • the plasma generation chamber is defined by at least one tubular-shaped neutrode segment.
  • the plasma generation chamber is defined by at least a first and a second tubular segment connected together removably.
  • the gas injection channel may be defined between the first and second segments.
  • the torch further comprises a plasma ejection nozzle located downstream of the anode and the cathode.
  • the gas under pressure is an oxidizing gas under pressure.
  • the gas under pressure is a neutral gas under pressure.
  • the figure 2 is a longitudinal section of an example of a plasma torch 1 according to the invention.
  • the cup of the figure 2 was performed in a first section plane intersecting the introduction ports 9 of the pressurized gas G into the torch 1.
  • the torch 1 extends along a longitudinal axis X.
  • the torch 1 comprises a chamber 3 for generating a plasma extending along the axis X.
  • the torch 1 comprises several introduction ports 9 of the gas G.
  • the ports 9 are, in the illustrated example, positioned around the axis X.
  • the ports 9 are positioned symmetrically or not with respect to the axis X.
  • the chamber 3 is in communication with each of the ports 9.
  • the gas G under pressure, intended to form the plasma, is injected through each of the ports 9. This gas G is then transferred to the chamber 3 in which the plasma is generated. .
  • Each of the ports 9 comprises an inlet 9a which is connected to a source of G gas under pressure (not shown) and an outlet 9b which opens inside the torch 1. This outlet 9b opens into a channel 11a of gas transfer G under pressure. Each of the exits 9b opens into a separate transfer channel 11a. Each transfer channel 11a extends along the axis X. The transfer channels 11a are positioned symmetrically or otherwise with respect to the axis X.
  • Each transfer channel 11a communicates with at least one injection channel 5 of the pressurized gas which opens into the chamber 3.
  • the transfer channel 11a connects the outlet 9b to at least one injection channel 5.
  • the injection channel 5 connects the transfer channel 11a to the chamber 3.
  • Two injection channels 5 connected to the same transfer channel 11a are visible on the figure 4 . As visible on the figure 4 , the injection channel 5 extends transversely with respect to the transfer channel 11a. The injection channel 5 extends transversely with respect to the X axis.
  • the chamber 3 is thus placed in communication with a port 9 via a transfer channel 11a and an injection channel 5.
  • the pressurized gas G thus initially passes through the ports 9, then the transfer channels 11a, then the injection channels 5 in order to be introduced into the chamber 3 and form the plasma.
  • the path of the gas G is indicated by the arrows G on the figures 2 and 4 .
  • the illustrated example relates to the case of a torch 1 provided with a plurality of ports 9 for introducing the gas G.
  • the torch 1 comprises a single port of introduction of the gas under pressure. In which case, it is possible to have only one transfer channel 11a.
  • a plurality of ports 9 positioned around the X axis have been included in the illustrated example.
  • the ports could, in a non-illustrated variant, be shifted along the X axis.
  • the torch 1 comprises an anode 20 and a cathode 30 which are located on either side of the plasma generation chamber 3.
  • the chamber 3 is thus located between the anode 20 and the cathode 30.
  • the anode 20, the chamber 3 and the cathode 30 follow one another as one moves along the axis X.
  • a difference of sufficient potential is applied between the anode 20 and the cathode 30 in order to generate an electric arc A.
  • the generated electric arc A extends in the chamber 3 between the anode 20 and the cathode 30 and makes it possible to generate the plasma by ionization of the gas G injected.
  • the anode 20, the cathode 30 and their coils 24 and 34 for generating the associated magnetic field will be described in more detail below.
  • the injected gas G can be a neutral gas and for example be chosen from: argon, helium, nitrogen and their mixtures.
  • the gas G may be an oxidizing gas, such as air.
  • one of the advantages of the torch according to the invention is to allow a satisfactory use, if desired, of an oxidizing gas to generate the plasma.
  • the chamber 3 is defined by a plurality of segments 13 of tubular shape positioned successively along the axis X.
  • the chamber 3 is defined inside the segments 13.
  • Each transfer channel 11a passes through the segments 13.
  • Each segment 13 constitutes a neutrode in the example under consideration.
  • the segments 13 are not polarized (electrically neutral) in order to prevent the electrical arc A from catching on these segments 13.
  • the neutrode segments 13 are not electrically connected to the anode 20 and at the cathode 30.
  • One or more electrically insulating elements may be disposed between the set of segments 13 and each electrode 20 or 30.
  • a layer of an electrically insulating material may furthermore be positioned between each segment 13 so as to electrically isolating the segments 13 from each other.
  • the illustrated example relates to a case where the chamber 3 is defined by several segments 13 positioned successively along the axis X. However, it is not beyond the scope of the invention when the chamber is defined only by a single segment. .
  • the anode 20 and the cathode 30 are thus separated by a material on which the electric arc can not cling.
  • This makes it possible to favor the attachment of the arc A at the level of the anode 20 and of the cathode 30, and this therefore contributes to reducing the fluctuations of the length of the arc in operation, thus conferring on the plasma generated a greater stability.
  • the exemplary torch 1 illustrated uses a plurality of neutrode segments 13 interconnected removably. As visible especially on figures 3 and 4 , the connection of the segments 13 is ensured by insertion of fastening elements 13a, such as pins, in housings 13c formed in each of the segments 13. The segments 13 are thus, in the illustrated example, nested with each other removably.
  • the fact of defining the chamber 3 by means of several segments 13 interconnected removably allows advantageously to adjust the distance separating the anode 20 from the cathode 30 by the number of segments used.
  • the length of the arc thus becomes a parameter that can be used to adjust the characteristics of the plasma generated, as well as the intensity of the current and the gas flow rate.
  • it is possible to generate arcs of increased length which makes it possible, for the same power, to reduce the intensity of current used and thus to further extend the service life of the electrodes.
  • the segments 13 each have substantially the same thickness. Unless otherwise stated, the thickness of a segment 13 is measured along the X axis. However, it is not beyond the scope of the invention when the chamber 3 is formed by assembling a plurality of thickness segments. different.
  • FIG. figure 4 shows a first segment 13 (lower segment in the figure) and a second segment 13 (upper segment in the figure) which is adjacent to the first segment.
  • each segment 13 comprises a first portion 132 and a second portion 133.
  • the first portion 132 may be formed of an electrically conductive material, such as copper.
  • the second portion 133 is formed of an electrically insulating material and electrically isolates two segments 13 adjacent to each other.
  • the first portion 132 has a face 130, located opposite an adjacent segment 13, on which is formed the injection channel 5.
  • the second portion 133 of the second segment covers the injection channel 5 of the first segment.
  • the second portion of the second segment defines axially along the X axis the injection channel 5 of the first segment.
  • the injection channel 5 of the first segment is defined between the first and the second segment.
  • An annular seal 131 may, as illustrated, be present between the first and second segments.
  • the seal 131 makes it possible to ensure a radial seal.
  • injection channels when there are several injection channels, these may or may not be regularly spaced along the X axis.
  • the torch 1 further comprises an envelope 15 made of an electrically insulating material which surrounds the chamber 3 and the segments 13.
  • the envelope 15 extends along the axis X.
  • fastening elements 100 such as studs, can be used (see FIG. figure 5 showing the fastening elements 100 passing through the envelope 15).
  • the envelope 15 may be divided into several parts, as illustrated.
  • the torch 1 further comprises an outer body 2 inside which are in particular present, the anode 20 and the cathode 30, the plasma generation chamber 3, the segments 13 and the envelope 15.
  • This body 2 can, as illustrated, be divided into several parts. The joining of the parts 2b and 2a can be done by screwing the part 2b on the part 2a. Parts 2b and 2d can, for their part, be secured through the ring 2c.
  • the segments 13 defining the plasma generation chamber 3 are cooled by circulation of a cooling fluid F. This aspect will now be described, particularly in relation to figure 3 .
  • the cut reproduced in figure 3 was made in a second section plane, different from the first section plane associated with the figure 2 .
  • the second cutting plane intersects in particular the ports 19 for introducing the cooling fluid.
  • the torch 1 comprises several ports 19 for introducing the cooling fluid F.
  • the ports 19 are, in the illustrated example, positioned around the axis X.
  • the ports 19 may or may not be positioned symmetrically with respect to the axis X.
  • Each of the ports 19 comprises an inlet 19a which is connected to a source of cooling fluid (not shown) and an outlet 19b opening inside the torch 1.
  • the outlet 19b opens into a plurality of cooling channels 11b.
  • the cooling channels 11b extend along the axis X.
  • the channels 11b pass through the segments 13.
  • the cooling channels 11b are, in the example shown, positioned around the axis X.
  • the channels 11b can or not be evenly distributed around the X axis.
  • the torch 1 further comprises several ports 29 for outputting the coolant F.
  • the ports 29 are, in the example shown, positioned around the axis X.
  • the ports 29 may or may not be positioned symmetrically with respect to the X axis.
  • Each of the ports 29 includes an inlet 29a which is in communication with the cooling channels 11b and an outlet 29b in communication with a cooling fluid discharge circuit (not shown).
  • the outputs 19b are positioned at a first end E1 of the chamber 3 and the inputs 29a are positioned at a second end E2 of the chamber 3, opposite the first end.
  • the segments 13 are located between the ports 19 and the ports 29.
  • Each cooling channel 11b connects an output 19b to an input 29a.
  • the fluid F is introduced through the ports 19, then flows through the cooling channels 11b, and is then discharged outside the torch 1 by the ports 29.
  • This fluid path F is materialized at the figure 3 by the arrows F.
  • the torch 1 is, moreover, provided with a convergent 60 and a divergent 70.
  • the plasma generation chamber 3 is located between the convergent 60 and the divergent 70.
  • the convergent 60 may be located upstream of the chamber 3 and the divergent 70 downstream of the chamber 3.
  • upstream and downstream are used here with reference to the flow direction of the plasma towards the outside of the torch 1 (see arrow FP on the figure 2 ).
  • the convergent 60 is located between the anode 20 and the chamber 3.
  • the convergent 60 may open opposite the anode 20.
  • the divergent 70 is located between the chamber 3 and the cathode 30.
  • the divergent 70 may end up opposite the cathode 30.
  • the convergent 60 has a sectional narrowing as it moves towards the chamber 3.
  • the section of the convergent 60 on the anode side 20 is greater than the section of the convergent 60 on the side of the chamber 3.
  • the divergent 70 has a sectional widening as it moves in the direction towards the cathode 30.
  • the section of the divergent 70 on the cathode side 30 is greater than the section of the divergent 70 on the side of the chamber 3.
  • the presence of the convergent 60 and the divergent 70 which each have an enlarged section on the side of the electrodes 20 and 30 advantageously allows the arc to attach more easily to the latter and thus to further improve the stability of the plasma generated. .
  • the central part of the torch 1 has just been described.
  • the description which follows sets out to describe in more detail the parts of this torch located on either side of this central part, and in particular the structure of the anode 20 and the cathode 30.
  • the anode 20 and the cathode 30 are located on either side of the plasma generation chamber 3.
  • the anode 20 is located on the side of the first end E1 of the chamber 3 and the cathode 30 on the side of the second end E2 of the chamber 3, opposite to the first end E1.
  • the anode 20 is located between a bottom 50 of the plasma torch 1 and the convergent 60.
  • the cathode 30 is, for its part, located between the divergent 70 and the ejection nozzle 80 of the plasma torch 1.
  • the bottom 50 may, as illustrated, be provided with an injection orifice 52 of a buffer gas GT.
  • the bottom 50 has a neck 50a intended to be connected to a buffer gas source (not shown).
  • the neck 50a defines an orifice 52 through which the buffer gas GT is intended to be injected (see GT injection arrow on the figure 2 ).
  • the injection of the buffer gas GT through the orifice 52 makes it possible to form a "cushion" of buffer gas GT upstream of the anode 20 so as to prevent the arc A from catching on the bottom 50 during the operation. This also helps to stabilize the length of the arc during operation and thus to give the plasma a greater stability.
  • the GT buffer gas used can be a neutral gas, for example chosen from: argon, helium, nitrogen and their mixtures.
  • the anode 20 and the cathode 30 each comprise an electrically conductive body, respectively 22 and 32.
  • Each conductive body 22 or 32 defines an electrically conductive outer surface, denoted S1 or S2, which is annular in shape.
  • S1 or S2 extends 360 ° about the X axis.
  • the outer surface S1 or S2 can have a shape of revolution.
  • the conductive body 22 or 32 has in the example illustrated a toroidal shape.
  • the conductive body 22 or 32 has a U-shape when the torch 1 is observed in longitudinal section.
  • Arc A comprises a central portion extending through chamber 3 and arc feet PA connecting this central portion to anode 20 and cathode 30.
  • FIG. 6 A more detailed section of anode 20 is provided at figure 6 .
  • the cathode 30 has a similar structure.
  • the conductive body 22 may be copper or copper alloy. Other electrically conductive materials are conceivable to constitute the conductive body 22. The use of copper however remains preferential in order to optimize the diffusion of calories in the body, and thus to make it possible to further increase the service life. of the electrode.
  • the conductive body 22 comprises, in the illustrated example, two separate parts 22a and 22b assembled, for example by welding, along an assembly surface 22c. Each portion 22a and 22b extends 360 ° about the axis X.
  • the portions 22a and 22b each comprise a positioning relief 22d or 22e intended to cooperate with a complementary relief, respectively 53 or 39 (see figure 2 ), to ensure the correct positioning of the electrode in the torch 1.
  • the positioning reliefs 22d and 22e can each have an annular shape and extend around the axis X.
  • the positioning reliefs 22d and 22e can each extend 360 ° around the X axis.
  • the conductive body 22 defines an internal volume 23 in which there is a first coil 24 for generating a magnetic field.
  • the inner volume 23 may also have an annular shape, and extend 360 ° about the X axis.
  • the first coil 24 comprises a winding of an electrically conductive wire 26 positioned around the surface S1.
  • the wire 26 is traversed by an electric current thus making it possible to generate an induced magnetic field.
  • This magnetic field generates a force making it possible to turn the feet PA of the electric arc A around the axis X.
  • This rotation is materialized by the arrow R on the figure 2 .
  • This rotation makes it possible to distribute the erosion of the electrodes due to the electric arc on the external surface of the body and, consequently, to increase the lifetime of the electrodes.
  • Another advantage resulting from this increased lifetime of the electrodes is the possibility of using an oxidizing gas to generate the plasma.
  • the use of an oxidizing gas makes it possible to limit the cost of using the torch 1 on applications that tolerate the presence of oxygen. In particular, it is possible, if desired, to dispense with the use of helium in the gas G, which has a relatively high cost.
  • the wire 26 may be copper or copper alloy. Other conductive materials are however usable to form the wire.
  • the wire 26 is present on a coil support 28.
  • the support 28 has a toric shape.
  • the support 28 has a U-shape when the torch 1 is observed in longitudinal section.
  • the winding of the wire 26 reproduces the curvature of the support 28.
  • the first coil 24 thus has a U shape when the torch 1 is observed in longitudinal section.
  • the wire 26 extends 360 ° about the X axis.
  • the wire 26 is wound in a spiral around the X axis.
  • the wire 26 defines a first spiral 261 in a first plane P1 transverse to the X axis and a second spiral 263 in a second plane P2 transverse to the axis X and offset from the first plane P1 along this axis (see figure 7 ).
  • the wire 26 further defines a transition zone 265 between the first 261 and second 263 spirals.
  • the radius of this winding is decreasing and increasing.
  • the radius of the winding is decreasing in the first region R1 and then increasing in the second region R2.
  • the first and second regions are shifted along the X axis.
  • the first coil 24 may or may not be symmetrical with respect to a plane P transverse to the X axis.
  • the embodiment of the anode 20, respectively of the cathode 30, comprises the winding of the wire 26, respectively 36, on the support 28, respectively 38.
  • This winding can be performed in a toroid mold whose section is shaped
  • the coil is then connected to two electrical connection terminals.
  • the first 24 and second 34 coils thus obtained are then fixed and secured to the support by injection and hardening of an insulating resin of electricity.
  • torch 1 comprises a single anode 20 and a single cathode 30. However, it is not beyond the scope of the invention if the torch comprises several anodes and / or several cathodes.
  • the anode 20 is located on the side of the bottom 50 and the cathode 30 on the side opposite the anode 20.
  • the polarization could, however, be reversed: the cathode would in this case be positioned on the side of the bottom 50 and the anode on the opposite side to the cathode.
  • the content of this detailed description is also valid in the case where the polarization is reversed.
  • the first 24 and second 34 coils can significantly improve the life of the anode 20 and the cathode 30. Another feature to further improve the life of the electrodes is relative to the circuit for cooling the these during operation. This cooling circuit will now be described for the anode 20, it being understood that the cooling of the cathode 30 is operated in a similar manner.
  • the conductive body 22 has an internal surface S3 at which the cooling of the anode 20 is intended to be realized (see figure 6 ).
  • the inner surface S3 is in communication with an orifice 46b for introducing a cooling fluid F.
  • the cooling is thus carried out as close as possible to the electric arc A, which makes it possible to optimize its efficiency, and to further improve the service life of the electrodes by limiting the erosion due to the electric arc.
  • the limitation of the erosion due to the arc is advantageous, in particular, in the case where the torch 1 is used to make a deposition of a material by plasma way in order to limit the "pollution" of the plasma flux, and therefore deposition performed by the eroded electrode material.
  • the torch 1 comprises at least one port 46 for introducing a cooling fluid F at each of the electrodes 20 and 30.
  • Port 46 comprises an inlet 46a which is connected to a source of cooling fluid (not shown) and an outlet 46b opening inside the body 22.
  • the outlet 46b opens into the internal volume 23 of the body 22.
  • the port 46 is formed of two distinct parts, namely: a first portion 48 defining the inlet 46a and a second portion 47 defining the outlet 46b and inserted inside the first portion 48.
  • the port 46 could be formed of a single piece.
  • the torch 1 further comprises at least one output port of a cooling fluid F at each of the electrodes 20 and 30.
  • the output port located at the anode 20 is noted 40 and the port located at the level of the cathode 30 is noted 140 (see figure 3 ).
  • Port 40 includes an inlet 40a in communication with the interior volume 23 and an outlet 40b in communication with a cooling fluid discharge system (not shown).
  • Port 40 and port 46 may or may not be positioned symmetrically with respect to the X axis.
  • the cooling fluid F is introduced into the internal volume 23 through the port 46.
  • the fluid F then circulates in the internal volume 23.
  • the fluid F is in contact with the inner surface S3 in order to achieve the cooling of the body 22 or 32.
  • the coil 24 is located at a non-zero distance from the body 22. This distance can typically be less than or equal to 3 mm.
  • the latter is evacuated outside the torch 1 through the port 40.
  • the path of the cooling fluid F in the body 22 is materialized, at the figure 6 , by the arrows F.
  • the presence of the coils and the electrode cooling circuit advantageously contributes to increasing the service life of the latter.
  • the following description sets out to detail another aspect of the example of torch 1 illustrated, relating to the ejection nozzle 80.
  • the ejection nozzle 80 is situated downstream of the anode 20 and the cathode 30.
  • the plasma is intended to be distributed outside the torch 1 through the ejection nozzle (FP plasma stream). figure 2 ).
  • the ejection nozzle 80 defines a plasma ejection channel 81 in communication with the chamber 3.
  • the channel 81 extends along the axis X.
  • the channel 81 opens out of the torch 1 through of the outlet port 88.
  • the ejection nozzle 80 shown has a nozzle shape.
  • the ejection nozzle 80 thus comprises a convergent 82 located on the side of the chamber 3, a diverging 86 located on the side of the outlet orifice 88 and a collar 84 between the convergent 82 and the divergent 86.
  • the section of the convergent 82 on the side of the chamber 3 is greater than the section of the convergent 82 on the side of the orifice 88.
  • the section of the divergent 86 on the side of the chamber 3 is less than the section of the divergent 86 on the side of the orifice 88.
  • the ejection nozzle can only have a convergent and be devoid of divergent.
  • the shape of the ejection channel 81 is determined according to the intended application for the plasma torch 1. It is part of the general knowledge of those skilled in the art to adapt the shape of this channel 81 to the desired application.
  • the ejection nozzle 80 is also provided with a cooling circuit.
  • the ejection nozzle 80 defines an interior volume 92 in which a cooling fluid is intended to circulate.
  • This interior volume 92 may extend 360 ° about the axis X.
  • the interior volume 92 may be located around the ejection channel 81.
  • the figure 3 illustrates the details of the cooling system of the nozzle 80.
  • the torch 1 may comprise at least one port 90 for introducing a cooling fluid F opening into the internal volume 92.
  • the port 90 comprises an inlet 90a which is connected to a coolant source (not shown) and an outlet 90b opening into the interior volume 92.
  • the torch 1 may further comprise at least one port 94 for outputting the cooling fluid F in communication with the interior volume 92.
  • the port 94 and the port 90 may or may not be positioned symmetrically with respect to the X axis.
  • 94 includes an inlet 94a in communication with the interior volume 92 and an outlet 94b connected to a cooling fluid discharge system (not shown).
  • the cooling fluid F is introduced into the internal volume 92 through the port 90.
  • the cooling fluid F then passes through the internal volume 92 in order to carry out the cooling of the ejection nozzle 80.
  • the cooling fluid F is then evacuated through the output port 94.
  • the fluid path of cooling in the interior volume 92 is indicated by the arrows F on the figure 3 .
  • the ejection nozzle 80 may be removably attached to the remainder of the torch 1 comprising the anode 20 and the cathode 30. This advantageously makes it possible to modify the flow forming element in order to adapt the same system to different applications. Note however that the presence of an ejection nozzle remains optional.
  • the torch may comprise at least one introduction channel of a material to be deposited by a plasma process opening downstream of the plasma generation chamber.
  • a plasma process opening downstream of the plasma generation chamber.
  • the material is introduced into the generated plasma stream in order to be deposited on the substrate.
  • the introduction channel may open downstream of the anode and the cathode.
  • the introduction channel may open between an electrode and the ejection nozzle.
  • the introduction channel may alternatively lead downstream of the ejection nozzle.
  • the invention is however not limited to the use of the torch for producing a plasma coating.
  • figure 8 a simplified electrical diagram showing a first electrical system 203 in which the body 22 of the anode 20 and the body 32 of the cathode 30 are connected in series across a first electrical generator GE1.
  • the first electrical system 203 makes it possible to ensure the formation of the plasma.
  • the figure 8 further shows a second electrical system 205 in which the first 24 and second 34 coils are connected in series across a second electrical generator GE2.
  • the second electrical system 205 ensures the creation of the induced magnetic field to rotate the electric arc and thus prolong the life of the electrodes.
  • the anode 20 and the cathode 30 In operation, it is possible to impose between the anode 20 and the cathode 30 a voltage of between 150 V and 400 V, for example between 200 V and 300 V.
  • the intensity of the current flowing between the anode 20 and the cathode 30 may be less than or equal to 200 A.
  • the intensity of the current flowing in the first and second coils 24 and 34 may be less than or equal to 200 A.

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  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Plasma Technology (AREA)

Description

Arrière-plan de l'inventionBackground of the invention

L'invention concerne une torche à plasma comprenant une anode et une cathode chacune munies d'une bobine de génération d'un champ magnétique. Les anode et cathode de la torche selon l'invention présentent une durée de vie augmentée.The invention relates to a plasma torch comprising an anode and a cathode each provided with a coil for generating a magnetic field. The anode and cathode of the torch according to the invention have an increased life.

Les torches à plasma sont des équipements qui ont commencé à apparaître au début des années 1930 avec le développement de l'électricité pour une finalité industrielle. Le développement réel de ces systèmes dans le monde industriel est effectif depuis les années 1970, on retrouve ces systèmes dans la sidérurgie ainsi que la chimie des procédés.Plasma torches are equipment that began to appear in the early 1930s with the development of electricity for an industrial purpose. The real development of these systems in the industrial world is effective since the 1970s, we find these systems in the iron and steel industry as well as process chemistry.

Le document US 3,832,519 divulgue un exemple de torche à plasma comprenant anode et cathode munies de bobines générant un champ magnétique.The document US 3,832,519 discloses an example of a plasma torch comprising anode and cathode provided with coils generating a magnetic field.

On a représenté à la figure 1 un modèle de base d'une torche 200 de génération d'un plasma selon l'art antérieur. Cette torche 200 comporte une anode métallique 202 en forme de pointe et une cathode 204 en forme de cône. Un arc électrique A s'établit entre l'anode 202 et la cathode 204. Un gaz est injecté entre les deux électrodes (flèches 208) afin de former le flux de plasma FP.We have shown figure 1 a basic model of a torch 200 for generating a plasma according to the prior art. This torch 200 comprises a metal anode 202 in the form of a tip and a cathode 204 in the form of a cone. An electric arc A is established between the anode 202 and the cathode 204. A gas is injected between the two electrodes (arrows 208) in order to form the FP plasma stream.

Un premier problème de ce type de torche à plasma est relatif à l'érosion des électrodes 202 et 204 produite par l'arc A qui affecte la durée de vie de ces dernières. Une limitation supplémentaire liée à cette durée de vie réduite des électrodes dans l'art antérieur est que seuls des gaz neutres ou non oxydants peuvent être utilisés afin de générer le plasma. En effet, l'oxygène atomique généré dans un plasma dégrade les électrodes plus rapidement encore. Or, des gaz neutres, comme l'hélium, peuvent être onéreux, contribuant ainsi à rendre relativement élevé le coût de mise en oeuvre des torches de l'art antérieur.A first problem of this type of plasma torch is related to the erosion of the electrodes 202 and 204 produced by the arc A which affects the life of the latter. An additional limitation related to this reduced electrode life in the prior art is that only neutral or non-oxidizing gases can be used to generate the plasma. In fact, the atomic oxygen generated in a plasma degrades the electrodes even more rapidly. However, neutral gases, such as helium, can be expensive, thus helping to make relatively high the cost of implementation torches of the prior art.

Un deuxième problème qui peut être rencontré avec les torches à plasma de l'art antérieur est que l'arc A est libre d'aller s'accrocher à n'importe quelle position de la cathode 204. Ce libre positionnement de l'arc engendre une fluctuation de sa longueur dans le temps. La longueur de l'arc étant directement représentative de la tension de l'arc, il en résulte une fluctuation significative de la tension, et donc de la puissance.A second problem that can be encountered with the prior art plasma torches is that the arc A is free to hang on at any position of the cathode 204. This free positioning of the arc generates a fluctuation of its length in time. The length of the arc being directly representative of the voltage of the arc, this results in a significant fluctuation of the voltage, and therefore of the power.

Il existe donc un besoin pour augmenter la durée de vie des électrodes des torches à plasma.There is therefore a need to increase the life of the plasma torch electrodes.

Il existe aussi un besoin pour rendre plus stable la longueur de l'arc généré en fonctionnement.There is also a need to make the length of the arc generated during operation more stable.

Objet et résumé de l'inventionObject and summary of the invention

A cet effet, l'invention propose, selon un premier aspect, une torche à plasma selon la revendication 1.For this purpose, the invention proposes, according to a first aspect, a plasma torch according to claim 1.

Les première et deuxième bobines permettent de générer un champ magnétique induit engendrant une force permettant de faire tourner l'arc électrique formé entre l'anode et la cathode. Cette rotation de l'arc électrique permet de répartir l'érosion des électrodes sur la surface externe du corps et, par conséquent, d'augmenter la durée de vie des électrodes.The first and second coils can generate an induced magnetic field generating a force for rotating the electric arc formed between the anode and the cathode. This rotation of the electric arc makes it possible to distribute the erosion of the electrodes on the external surface of the body and, consequently, to increase the lifetime of the electrodes.

Dans un exemple de réalisation, chaque corps conducteur présente une surface interne en communication avec un orifice d'introduction d'un fluide de refroidissement.In an exemplary embodiment, each conductive body has an internal surface in communication with a coolant introduction orifice.

Dans un exemple de réalisation, chaque corps conducteur a une forme torique. En particulier, chacune des première et deuxième bobines est portée par un support de bobine ayant une forme torique.In an exemplary embodiment, each conductive body has a toric shape. In particular, each of the first and second coils is carried by a coil carrier having a toroidal shape.

Dans un exemple de réalisation, la torche comprend une unique cathode et une unique anode.In an exemplary embodiment, the torch comprises a single cathode and a single anode.

Dans un exemple de réalisation, chaque corps conducteur est en cuivre ou en alliage de cuivre.In an exemplary embodiment, each conductive body is made of copper or copper alloy.

Dans un exemple de réalisation, la chambre de génération du plasma est définie par au moins un segment de neutrode de forme tubulaire.In an exemplary embodiment, the plasma generation chamber is defined by at least one tubular-shaped neutrode segment.

Dans un exemple de réalisation, la chambre de génération du plasma est définie par au moins un premier et un deuxième segments de forme tubulaire reliés entre eux de manière amovible. En particulier, le canal d'injection de gaz peut être défini entre les premier et deuxième segments.In an exemplary embodiment, the plasma generation chamber is defined by at least a first and a second tubular segment connected together removably. In particular, the gas injection channel may be defined between the first and second segments.

Dans un exemple de réalisation, la torche comprend en outre une buse d'éjection du plasma située en aval de l'anode et de la cathode.In an exemplary embodiment, the torch further comprises a plasma ejection nozzle located downstream of the anode and the cathode.

La présente invention vise également un ensemble utile pour la génération d'un plasma comprenant au moins :

  • une torche à plasma telle que décrite plus haut, et
  • une source de gaz sous pression en communication avec le canal d'injection.
The present invention also provides a useful assembly for generating a plasma comprising at least:
  • a plasma torch as described above, and
  • a source of pressurized gas in communication with the injection channel.

Dans un exemple de réalisation, le gaz sous pression est un gaz oxydant sous pression. En variante, le gaz sous pression est un gaz neutre sous pression.In an exemplary embodiment, the gas under pressure is an oxidizing gas under pressure. In a variant, the gas under pressure is a neutral gas under pressure.

Brève description des dessinsBrief description of the drawings

D'autres caractéristiques et avantages de l'invention ressortiront de la description suivante, donnée à titre non limitatif, en référence aux dessins annexés, sur lesquels :

  • la figure 1 représente une vue en coupe longitudinale d'une torche à plasma de l'art antérieur,
  • la figure 2 représente une vue en coupe longitudinale, réalisée selon un premier plan de coupe, d'un exemple de torche à plasma selon l'invention,
  • la figure 3 représente une vue en coupe longitudinale, réalisée selon un deuxième plan de coupe, de la torche à plasma de la figure 2,
  • la figure 4 est une vue éclatée d'une partie de la torche à plasma de la figure 2 montrant notamment un canal d'injection du gaz débouchant dans la chambre de génération du plasma,
  • la figure 5 est une vue en perspective d'une partie d'une coupe de la torche à plasma de la figure 2,
  • la figure 6 est une vue en coupe d'une partie de la torche à plasma de la figure 2 montrant, de manière isolée, l'anode et la première bobine de génération du champ magnétique,
  • la figure 7 est une vue en perspective de la première bobine de génération du champ magnétique illustrée à la figure 6 prise isolément, et
  • la figure 8 illustre le raccordement de différents éléments de la torche à plasma à des générateurs électriques.
Other features and advantages of the invention will emerge from the following description, given in a non-limiting manner, with reference to the appended drawings, in which:
  • the figure 1 represents a longitudinal sectional view of a plasma torch of the prior art,
  • the figure 2 represents a longitudinal sectional view, taken along a first section plane, of an example of a plasma torch according to the invention,
  • the figure 3 represents a longitudinal sectional view, taken along a second section plane, of the plasma torch of the figure 2 ,
  • the figure 4 is an exploded view of a portion of the plasma torch of the figure 2 showing in particular a gas injection channel opening into the plasma generation chamber,
  • the figure 5 is a perspective view of part of a section of the plasma torch of the figure 2 ,
  • the figure 6 is a sectional view of a portion of the plasma torch of the figure 2 showing, in isolation, the anode and the first coil of generation of the magnetic field,
  • the figure 7 is a perspective view of the first generation coil of the magnetic field illustrated in FIG. figure 6 taken alone, and
  • the figure 8 illustrates the connection of different elements of the plasma torch to electric generators.

Description détaillée de modes de réalisationDetailed description of embodiments

Un exemple de torche à plasma 1 selon l'invention va être décrit en lien avec les figures 2 à 7. La partie centrale de la torche 1 va tout d'abord être décrite.An example of a plasma torch 1 according to the invention will be described in connection with the Figures 2 to 7 . The central part of the torch 1 will first be described.

La figure 2 est une coupe longitudinale d'un exemple de torche à plasma 1 selon l'invention. La coupe de la figure 2 a été réalisée dans un premier plan de coupe intersectant les ports d'introduction 9 du gaz sous pression G dans la torche 1.The figure 2 is a longitudinal section of an example of a plasma torch 1 according to the invention. The cup of the figure 2 was performed in a first section plane intersecting the introduction ports 9 of the pressurized gas G into the torch 1.

La torche 1 s'étend selon un axe longitudinal X. La torche 1 comprend une chambre 3 de génération d'un plasma s'étendant selon l'axe X. La torche 1 comprend plusieurs ports d'introduction 9 du gaz G. Les ports 9 sont, dans l'exemple illustré, positionnés autour de l'axe X. Les ports 9 sont positionnés symétriquement ou non par rapport à l'axe X.The torch 1 extends along a longitudinal axis X. The torch 1 comprises a chamber 3 for generating a plasma extending along the axis X. The torch 1 comprises several introduction ports 9 of the gas G. The ports 9 are, in the illustrated example, positioned around the axis X. The ports 9 are positioned symmetrically or not with respect to the axis X.

La chambre 3 est en communication avec chacun des ports 9. Le gaz G sous pression, destiné à former le plasma, est injecté au travers de chacun des ports 9. Ce gaz G est ensuite transféré à la chambre 3 dans laquelle le plasma est généré.The chamber 3 is in communication with each of the ports 9. The gas G under pressure, intended to form the plasma, is injected through each of the ports 9. This gas G is then transferred to the chamber 3 in which the plasma is generated. .

Chacun des ports 9 comprend une entrée 9a qui est reliée à une source de gaz G sous pression (non représentée) et une sortie 9b qui débouche à l'intérieur de la torche 1. Cette sortie 9b débouche dans un canal 11a de transfert du gaz G sous pression. Chacune des sorties 9b débouche dans un canal 11a de transfert distinct. Chaque canal 11a de transfert s'étend le long de l'axe X. Les canaux 11a de transfert sont positionnés symétriquement ou non par rapport à l'axe X.Each of the ports 9 comprises an inlet 9a which is connected to a source of G gas under pressure (not shown) and an outlet 9b which opens inside the torch 1. This outlet 9b opens into a channel 11a of gas transfer G under pressure. Each of the exits 9b opens into a separate transfer channel 11a. Each transfer channel 11a extends along the axis X. The transfer channels 11a are positioned symmetrically or otherwise with respect to the axis X.

Chaque canal 11a de transfert communique avec au moins un canal 5 d'injection du gaz sous pression qui débouche dans la chambre 3. Le canal 11a de transfert relie la sortie 9b à au moins un canal 5 d'injection. Le canal 5 d'injection relie le canal 11a de transfert à la chambre 3. Deux canaux 5 d'injection reliés à un même canal 11a de transfert sont visibles sur la figure 4. Comme visible sur la figure 4, le canal 5 d'injection s'étend transversalement par rapport au canal 11a de transfert. Le canal 5 d'injection s'étend transversalement par rapport à l'axe X.Each transfer channel 11a communicates with at least one injection channel 5 of the pressurized gas which opens into the chamber 3. The transfer channel 11a connects the outlet 9b to at least one injection channel 5. The injection channel 5 connects the transfer channel 11a to the chamber 3. Two injection channels 5 connected to the same transfer channel 11a are visible on the figure 4 . As visible on the figure 4 , the injection channel 5 extends transversely with respect to the transfer channel 11a. The injection channel 5 extends transversely with respect to the X axis.

La chambre 3 est donc mise en communication avec un port 9 par l'intermédiaire d'un canal 11a de transfert et d'un canal 5 d'injection. Le gaz G sous pression traverse ainsi initialement les ports 9, puis les canaux 11a de transfert, puis les canaux 5 d'injection afin d'être introduit dans la chambre 3 et former le plasma. Le trajet du gaz G est matérialisé par les flèches G sur les figures 2 et 4.The chamber 3 is thus placed in communication with a port 9 via a transfer channel 11a and an injection channel 5. The pressurized gas G thus initially passes through the ports 9, then the transfer channels 11a, then the injection channels 5 in order to be introduced into the chamber 3 and form the plasma. The path of the gas G is indicated by the arrows G on the figures 2 and 4 .

L'exemple illustré concerne le cas d'une torche 1 munie d'une pluralité de ports 9 d'introduction du gaz G. On ne sort toutefois pas du cadre de l'invention lorsque la torche 1 comprend un unique port d'introduction du gaz sous pression. Auquel cas, il est possible de n'avoir qu'un seul canal 11a de transfert.The illustrated example relates to the case of a torch 1 provided with a plurality of ports 9 for introducing the gas G. However, it is not beyond the scope of the invention when the torch 1 comprises a single port of introduction of the gas under pressure. In which case, it is possible to have only one transfer channel 11a.

On notera aussi que, selon la longueur de la chambre 3, il est possible de disposer une pluralité de canaux 5 d'injection, comme dans l'exemple illustré, ou seulement un canal 5 d'injection. Ce dernier cas peut être adapté dans le cas d'une torche présentant une chambre de génération du plasma de longueur réduite.Note also that, depending on the length of the chamber 3, it is possible to have a plurality of injection channels 5, as in the example shown, or only an injection channel 5. This last case can be adapted in the case of a torch having a plasma generation chamber of reduced length.

On a, par ailleurs, fait figurer dans l'exemple illustré une pluralité de ports 9 positionnés autour de l'axe X. Les ports pourraient, dans une variante non illustrée, être décalés le long de l'axe X.In the illustrated example, a plurality of ports 9 positioned around the X axis have been included in the illustrated example. The ports could, in a non-illustrated variant, be shifted along the X axis.

La torche 1 comprend une anode 20 et une cathode 30 qui sont situées de part et d'autre de la chambre 3 de génération du plasma. La chambre 3 est ainsi située entre l'anode 20 et la cathode 30. L'anode 20, la chambre 3 et la cathode 30 se succèdent lorsque l'on se déplace le long de l'axe X. En fonctionnement, une différence de potentiel suffisante est appliquée entre l'anode 20 et la cathode 30 afin de générer un arc électrique A. L'arc électrique A généré s'étend dans la chambre 3 entre l'anode 20 et la cathode 30 et permet de générer le plasma par ionisation du gaz G injecté. L'anode 20, la cathode 30 et leurs bobines 24 et 34 de génération du champ magnétique associé seront décrites plus en détails dans la suite.The torch 1 comprises an anode 20 and a cathode 30 which are located on either side of the plasma generation chamber 3. The chamber 3 is thus located between the anode 20 and the cathode 30. The anode 20, the chamber 3 and the cathode 30 follow one another as one moves along the axis X. In operation, a difference of sufficient potential is applied between the anode 20 and the cathode 30 in order to generate an electric arc A. The generated electric arc A extends in the chamber 3 between the anode 20 and the cathode 30 and makes it possible to generate the plasma by ionization of the gas G injected. The anode 20, the cathode 30 and their coils 24 and 34 for generating the associated magnetic field will be described in more detail below.

Le gaz G injecté peut être un gaz neutre et par exemple être choisi parmi : l'argon, l'hélium, l'azote et leurs mélanges. En variante, le gaz G peut être un gaz oxydant, comme de l'air. Comme il sera rappelé plus bas, un des avantages de la torche selon l'invention est de permettre une utilisation satisfaisante, si cela est souhaité, d'un gaz oxydant pour générer le plasma.The injected gas G can be a neutral gas and for example be chosen from: argon, helium, nitrogen and their mixtures. Alternatively, the gas G may be an oxidizing gas, such as air. As will be recalled below, one of the advantages of the torch according to the invention is to allow a satisfactory use, if desired, of an oxidizing gas to generate the plasma.

Dans l'exemple illustré, la chambre 3 est définie par une pluralité de segments 13 de forme tubulaire positionnés successivement le long de l'axe X. La chambre 3 est définie à l'intérieur des segments 13. Chaque canal 11a de transfert traverse les segments 13.In the illustrated example, the chamber 3 is defined by a plurality of segments 13 of tubular shape positioned successively along the axis X. The chamber 3 is defined inside the segments 13. Each transfer channel 11a passes through the segments 13.

Chaque segment 13 constitue une neutrode dans l'exemple considéré. Ainsi, durant le fonctionnement les segments 13 ne sont pas polarisés (électriquement neutres) afin d'éviter l'accrochage de l'arc A électrique sur ces segments 13. Les segments 13 de neutrode ne sont pas reliés électriquement à l'anode 20 et à la cathode 30. On peut disposer un ou plusieurs éléments électriquement isolants entre l'ensemble de segments 13 et chaque électrode 20 ou 30. Une couche d'un matériau isolant de l'électricité peut en outre être positionnée entre chaque segment 13 afin d'isoler électriquement les segments 13 entre eux. L'exemple illustré concerne un cas où la chambre 3 est définie par plusieurs segments 13 positionnés successivement le long de l'axe X. On ne sort toutefois pas du cadre de l'invention lorsque la chambre n'est définie que par un unique segment.Each segment 13 constitutes a neutrode in the example under consideration. Thus, during operation, the segments 13 are not polarized (electrically neutral) in order to prevent the electrical arc A from catching on these segments 13. The neutrode segments 13 are not electrically connected to the anode 20 and at the cathode 30. One or more electrically insulating elements may be disposed between the set of segments 13 and each electrode 20 or 30. A layer of an electrically insulating material may furthermore be positioned between each segment 13 so as to electrically isolating the segments 13 from each other. The illustrated example relates to a case where the chamber 3 is defined by several segments 13 positioned successively along the axis X. However, it is not beyond the scope of the invention when the chamber is defined only by a single segment. .

Dans cette configuration où la chambre 3 est définie par un ou plusieurs segments de neutrode, l'anode 20 et la cathode 30 sont ainsi séparées par un matériau sur lequel l'arc électrique ne peut pas s'accrocher. Cela permet de favoriser un accrochage de l'arc A au niveau de l'anode 20 et de la cathode 30, et cela participe donc à réduire les fluctuations de la longueur de l'arc en fonctionnement, conférant ainsi au plasma généré une plus grande stabilité.In this configuration where the chamber 3 is defined by one or more neutrode segments, the anode 20 and the cathode 30 are thus separated by a material on which the electric arc can not cling. This makes it possible to favor the attachment of the arc A at the level of the anode 20 and of the cathode 30, and this therefore contributes to reducing the fluctuations of the length of the arc in operation, thus conferring on the plasma generated a greater stability.

Par ailleurs, l'exemple de torche 1 illustré met en oeuvre plusieurs segments de neutrode 13 reliés entre eux de manière amovible. Comme visible notamment sur les figures 3 et 4, la liaison des segments 13 est assurée par insertion d'éléments de fixation 13a, comme des pions, dans des logements 13c ménagés dans chacun des segments 13. Les segments 13 sont ainsi, dans l'exemple illustré, emboités les uns avec les autres de manière amovible.Moreover, the exemplary torch 1 illustrated uses a plurality of neutrode segments 13 interconnected removably. As visible especially on figures 3 and 4 , the connection of the segments 13 is ensured by insertion of fastening elements 13a, such as pins, in housings 13c formed in each of the segments 13. The segments 13 are thus, in the illustrated example, nested with each other removably.

Le fait de définir la chambre 3 à l'aide de plusieurs segments 13 reliés entre eux de manière amovible permet avantageusement d'ajuster la distance séparant l'anode 20 de la cathode 30 par le nombre de segments employés. De ce fait, il devient possible de modifier la longueur de l'arc A électrique généré par ajout ou retrait d'un ou plusieurs segments. La longueur de l'arc devient ainsi un paramètre utilisable pour ajuster les caractéristiques du plasma généré, au même titre que l'intensité du courant et le débit de gaz. Il est, en particulier, possible de générer des arcs de longueur augmentée, ce qui permet, pour la même puissance, de diminuer l'intensité de courant mis en oeuvre et donc d'étendre ainsi davantage encore la durée de vie des électrodes.The fact of defining the chamber 3 by means of several segments 13 interconnected removably allows advantageously to adjust the distance separating the anode 20 from the cathode 30 by the number of segments used. As a result, it becomes possible to modify the length of the electric arc A generated by adding or removing one or more segments. The length of the arc thus becomes a parameter that can be used to adjust the characteristics of the plasma generated, as well as the intensity of the current and the gas flow rate. In particular, it is possible to generate arcs of increased length, which makes it possible, for the same power, to reduce the intensity of current used and thus to further extend the service life of the electrodes.

Dans l'exemple illustré, les segments 13 présentent chacun sensiblement la même épaisseur. Sauf mention contraire, l'épaisseur d'un segment 13 est mesurée le long de l'axe X. On ne sort toutefois pas du cadre de l'invention lorsque la chambre 3 est formée par assemblage d'une pluralité de segments d'épaisseurs différentes.In the illustrated example, the segments 13 each have substantially the same thickness. Unless otherwise stated, the thickness of a segment 13 is measured along the X axis. However, it is not beyond the scope of the invention when the chamber 3 is formed by assembling a plurality of thickness segments. different.

Des détails relatifs aux segments 13 utilisés sont illustrés à la figure 4. La figure 4 montre un premier segment 13 (segment inférieur sur la figure) et un deuxième segment 13 (segment supérieur sur la figure) qui est adjacent au premier.Details of the segments 13 used are illustrated in FIG. figure 4 . The figure 4 shows a first segment 13 (lower segment in the figure) and a second segment 13 (upper segment in the figure) which is adjacent to the first segment.

Dans l'exemple considéré, chaque segment 13 comprend une première portion 132 et une deuxième portion 133. La première portion 132 peut être formée d'un matériau conducteur de l'électricité, comme du cuivre. La deuxième portion 133 est formée d'un matériau isolant de l'électricité et permet d'isoler électriquement deux segments 13 adjacents entre eux.In the example considered, each segment 13 comprises a first portion 132 and a second portion 133. The first portion 132 may be formed of an electrically conductive material, such as copper. The second portion 133 is formed of an electrically insulating material and electrically isolates two segments 13 adjacent to each other.

La première portion 132 présente une face 130, située en regard d'un segment 13 adjacent, sur laquelle est ménagé le canal 5 d'injection. La deuxième portion 133 du deuxième segment recouvre le canal 5 d'injection du premier segment. La deuxième portion du deuxième segment délimite axialement suivant l'axe X le canal 5 d'injection du premier segment. Dans l'exemple illustré, le canal 5 d'injection du premier segment est défini entre le premier et le deuxième segment. On pourrait en variante réaliser le canal d'injection au travers de chacun des segments (et pas entre deux segments adjacents).The first portion 132 has a face 130, located opposite an adjacent segment 13, on which is formed the injection channel 5. The second portion 133 of the second segment covers the injection channel 5 of the first segment. The second portion of the second segment defines axially along the X axis the injection channel 5 of the first segment. In the illustrated example, the injection channel 5 of the first segment is defined between the first and the second segment. One could alternatively realize the injection channel through each of the segments (and not between two adjacent segments).

Un joint d'étanchéité 131 annulaire peut, comme illustré, être présent entre les premier et deuxième segments. Le joint d'étanchéité 131 permet d'assurer une étanchéité radiale.An annular seal 131 may, as illustrated, be present between the first and second segments. The seal 131 makes it possible to ensure a radial seal.

On notera, par ailleurs, que lorsqu'il y a plusieurs canaux 5 d'injection, ces derniers peuvent ou non être régulièrement espacés le long de l'axe X.It should be noted, moreover, that when there are several injection channels, these may or may not be regularly spaced along the X axis.

Le fait de réaliser l'injection du gaz G au niveau du ou des segments 13 permet avantageusement de former, en fonctionnement, une couche de gaz « froide » non conductrice à proximité de ces derniers. Cette couche de gaz permet de réduire davantage encore le risque que l'arc ne vienne s'accrocher sur le ou les segments 13, et participe donc à améliorer la stabilité de la longueur de l'arc en fonctionnement.The fact of performing the injection of the gas G at the segment or segments 13 advantageously allows to form, in operation, a layer of "cold" non-conductive gas near the latter. This layer of gas makes it possible to further reduce the risk of the arc catching on the segment or segments 13, and therefore contributes to improving the stability of the length of the operating arc.

Dans l'exemple illustré, la torche 1 comprend en outre une enveloppe 15 formée d'un matériau isolant de l'électricité qui entoure la chambre 3 et les segments 13. L'enveloppe 15 s'étend le long de l'axe X. Afin d'assurer la fixation de l'enveloppe 15, des éléments de fixation 100, tels que des goujons, peuvent être utilisés (voir figure 5 montrant les éléments de fixation 100 traversant l'enveloppe 15). L'enveloppe 15 peut être sectorisée en plusieurs parties, comme illustré.In the example illustrated, the torch 1 further comprises an envelope 15 made of an electrically insulating material which surrounds the chamber 3 and the segments 13. The envelope 15 extends along the axis X. In order to secure the casing 15, fastening elements 100, such as studs, can be used (see FIG. figure 5 showing the fastening elements 100 passing through the envelope 15). The envelope 15 may be divided into several parts, as illustrated.

La torche 1 comprend en outre un corps 2 extérieur à l'intérieur duquel sont notamment présents, l'anode 20 et la cathode 30, la chambre 3 de génération de plasma, les segments 13 et l'enveloppe 15. Ce corps 2 peut, comme illustré, être sectorisé en plusieurs parties. La solidarisation des parties 2b et 2a peut être effectuée par vissage de la partie 2b sur la partie 2a. Les parties 2b et 2d peuvent, quant à elles, être solidarisées par l'intermédiaire de la bague 2c.The torch 1 further comprises an outer body 2 inside which are in particular present, the anode 20 and the cathode 30, the plasma generation chamber 3, the segments 13 and the envelope 15. This body 2 can, as illustrated, be divided into several parts. The joining of the parts 2b and 2a can be done by screwing the part 2b on the part 2a. Parts 2b and 2d can, for their part, be secured through the ring 2c.

Lors du fonctionnement, les segments 13 définissant la chambre 3 de génération du plasma sont refroidis par circulation d'un fluide F de refroidissement. Cet aspect va à présent être décrit, en lien notamment avec la figure 3.During operation, the segments 13 defining the plasma generation chamber 3 are cooled by circulation of a cooling fluid F. This aspect will now be described, particularly in relation to figure 3 .

La coupe reproduite à la figure 3 a été réalisée dans un deuxième plan de coupe, différent du premier plan de coupe associé à la figure 2. Le deuxième plan de coupe intersecte notamment les ports 19 d'introduction du fluide de refroidissement.The cut reproduced in figure 3 was made in a second section plane, different from the first section plane associated with the figure 2 . The second cutting plane intersects in particular the ports 19 for introducing the cooling fluid.

La torche 1 comprend plusieurs ports 19 d'introduction du fluide F de refroidissement. Les ports 19 sont, dans l'exemple illustré, positionnés autour de l'axe X. Les ports 19 peuvent ou non être positionnés symétriquement par rapport à l'axe X.The torch 1 comprises several ports 19 for introducing the cooling fluid F. The ports 19 are, in the illustrated example, positioned around the axis X. The ports 19 may or may not be positioned symmetrically with respect to the axis X.

Chacun des ports 19 comprend une entrée 19a qui est reliée à une source de fluide de refroidissement (non représentée) et une sortie 19b débouchant à l'intérieur de la torche 1. La sortie 19b débouche dans une pluralité de canaux de refroidissement 11b. Les canaux 11b de refroidissement s'étendent le long de l'axe X. Les canaux 11b traversent les segments 13. Les canaux de refroidissement 11b sont, dans l'exemple illustré, positionnés autour de l'axe X. Les canaux 11b peuvent ou non être régulièrement répartis autour de l'axe X.Each of the ports 19 comprises an inlet 19a which is connected to a source of cooling fluid (not shown) and an outlet 19b opening inside the torch 1. The outlet 19b opens into a plurality of cooling channels 11b. The cooling channels 11b extend along the axis X. The channels 11b pass through the segments 13. The cooling channels 11b are, in the example shown, positioned around the axis X. The channels 11b can or not be evenly distributed around the X axis.

La torche 1 comprend en outre plusieurs ports 29 de sortie du fluide de refroidissement F. Les ports 29 sont, dans l'exemple illustré, positionnés autour de l'axe X. Les ports 29 peuvent ou non être positionnés symétriquement par rapport à l'axe X.The torch 1 further comprises several ports 29 for outputting the coolant F. The ports 29 are, in the example shown, positioned around the axis X. The ports 29 may or may not be positioned symmetrically with respect to the X axis.

Chacun des ports 29 comprend une entrée 29a qui est en communication avec les canaux de refroidissement 11b et une sortie 29b en communication avec un circuit d'évacuation du fluide de refroidissement (non représenté). Les sorties 19b sont positionnées au niveau d'une première extrémité E1 de la chambre 3 et les entrées 29a sont positionnées au niveau d'une deuxième extrémité E2 de la chambre 3, opposée à la première extrémité. Les segments 13 sont situés entre les ports 19 et les ports 29. Chaque canal de refroidissement 11b relie une sortie 19b à une entrée 29a.Each of the ports 29 includes an inlet 29a which is in communication with the cooling channels 11b and an outlet 29b in communication with a cooling fluid discharge circuit (not shown). The outputs 19b are positioned at a first end E1 of the chamber 3 and the inputs 29a are positioned at a second end E2 of the chamber 3, opposite the first end. The segments 13 are located between the ports 19 and the ports 29. Each cooling channel 11b connects an output 19b to an input 29a.

Durant le fonctionnement, le fluide F est introduit au travers des ports 19, puis s'écoule au travers des canaux de refroidissement 11b, et est ensuite évacué à l'extérieur de la torche 1 par les ports 29. Ce trajet du fluide F est matérialisé à la figure 3 par les flèches F.During operation, the fluid F is introduced through the ports 19, then flows through the cooling channels 11b, and is then discharged outside the torch 1 by the ports 29. This fluid path F is materialized at the figure 3 by the arrows F.

On comprendra que la structure du circuit de refroidissement qui vient d'être décrite n'est fournie qu'à titre d'exemple. D'autres variantes sont envisageables comme le fait d'avoir un unique canal de refroidissement de forme annulaire et/ou un seul port 19 ou 29.It will be understood that the structure of the cooling circuit which has just been described is provided by way of example only. other variants are conceivable such as having a single annular cooling channel and / or a single port 19 or 29.

La torche 1 est, par ailleurs, munie d'un convergent 60 et d'un divergent 70. La chambre 3 de génération du plasma est située entre le convergent 60 et le divergent 70. Le convergent 60 peut être situé en amont de la chambre 3 et le divergent 70 en aval de la chambre 3. Les termes « amont » et « aval » sont utilisés ici en référence au sens d'écoulement du plasma vers l'extérieur de la torche 1 (voir flèche FP sur la figure 2).The torch 1 is, moreover, provided with a convergent 60 and a divergent 70. The plasma generation chamber 3 is located between the convergent 60 and the divergent 70. The convergent 60 may be located upstream of the chamber 3 and the divergent 70 downstream of the chamber 3. The terms "upstream" and "downstream" are used here with reference to the flow direction of the plasma towards the outside of the torch 1 (see arrow FP on the figure 2 ).

Le convergent 60 est situé entre l'anode 20 et la chambre 3. Le convergent 60 peut déboucher en regard de l'anode 20. Le divergent 70 est situé entre la chambre 3 et la cathode 30. Le divergent 70 peut déboucher en regard de la cathode 30.The convergent 60 is located between the anode 20 and the chamber 3. The convergent 60 may open opposite the anode 20. The divergent 70 is located between the chamber 3 and the cathode 30. The divergent 70 may end up opposite the cathode 30.

Le convergent 60 présente un rétrécissement de section lorsque l'on se déplace en direction de la chambre 3. La section du convergent 60 du côté de l'anode 20 est supérieure à la section du convergent 60 du côté de la chambre 3.The convergent 60 has a sectional narrowing as it moves towards the chamber 3. The section of the convergent 60 on the anode side 20 is greater than the section of the convergent 60 on the side of the chamber 3.

Le divergent 70 présente un élargissement de section lorsque l'on se déplace en direction en direction de la cathode 30. La section du divergent 70 du côté de la cathode 30 est supérieure à la section du divergent 70 du côté de la chambre 3.The divergent 70 has a sectional widening as it moves in the direction towards the cathode 30. The section of the divergent 70 on the cathode side 30 is greater than the section of the divergent 70 on the side of the chamber 3.

La présence du convergent 60 et du divergent 70 qui présentent chacun une section élargie du côté des électrodes 20 et 30 permet avantageusement à l'arc de s'accrocher plus facilement encore à ces dernières et donc d'améliorer davantage encore la stabilité du plasma généré.The presence of the convergent 60 and the divergent 70 which each have an enlarged section on the side of the electrodes 20 and 30 advantageously allows the arc to attach more easily to the latter and thus to further improve the stability of the plasma generated. .

La partie centrale de la torche 1 vient d'être décrite. La description qui suit s'attache à décrire plus en détails les parties de cette torche situées de part et d'autre de cette partie centrale, et notamment la structure de l'anode 20 et de la cathode 30.The central part of the torch 1 has just been described. The description which follows sets out to describe in more detail the parts of this torch located on either side of this central part, and in particular the structure of the anode 20 and the cathode 30.

Comme indiqué précédemment, l'anode 20 et la cathode 30 sont situées de part et d'autre de la chambre 3 de génération du plasma. L'anode 20 est située du côté de la première extrémité E1 de la chambre 3 et la cathode 30 du côté de la deuxième extrémité E2 de la chambre 3, opposée à la première extrémité E1.As indicated above, the anode 20 and the cathode 30 are located on either side of the plasma generation chamber 3. The anode 20 is located on the side of the first end E1 of the chamber 3 and the cathode 30 on the side of the second end E2 of the chamber 3, opposite to the first end E1.

Dans l'exemple illustré, l'anode 20 est située entre un fond 50 de la torche à plasma 1 et le convergent 60. La cathode 30 est, quant à elle, située entre le divergent 70 et la buse d'éjection 80 de la torche à plasma 1.In the illustrated example, the anode 20 is located between a bottom 50 of the plasma torch 1 and the convergent 60. The cathode 30 is, for its part, located between the divergent 70 and the ejection nozzle 80 of the plasma torch 1.

Le fond 50 peut, comme illustré, être muni d'un orifice d'injection 52 d'un gaz tampon GT. Le fond 50 présente un col 50a destiné à être relié à une source de gaz tampon (non représentée). Le col 50a définit un orifice 52 au travers duquel le gaz tampon GT est destiné à être injecté (voir flèche d'injection GT sur la figure 2).The bottom 50 may, as illustrated, be provided with an injection orifice 52 of a buffer gas GT. The bottom 50 has a neck 50a intended to be connected to a buffer gas source (not shown). The neck 50a defines an orifice 52 through which the buffer gas GT is intended to be injected (see GT injection arrow on the figure 2 ).

L'injection du gaz tampon GT au travers de l'orifice 52 permet de réaliser un « coussin » de gaz tampon GT en amont de l'anode 20 afin d'éviter que l'arc A ne s'accroche au fond 50, durant le fonctionnement. Cela participe donc aussi à stabiliser la longueur de l'arc durant le fonctionnement et donc à conférer au plasma une plus grande stabilité encore.The injection of the buffer gas GT through the orifice 52 makes it possible to form a "cushion" of buffer gas GT upstream of the anode 20 so as to prevent the arc A from catching on the bottom 50 during the operation. This also helps to stabilize the length of the arc during operation and thus to give the plasma a greater stability.

Le gaz tampon GT employé peut être un gaz neutre, par exemple choisi parmi : l'argon, l'hélium, l'azote et leurs mélanges.The GT buffer gas used can be a neutral gas, for example chosen from: argon, helium, nitrogen and their mixtures.

L'anode 20 et la cathode 30 comprennent chacune un corps conducteur de l'électricité, respectivement 22 et 32. Chaque corps conducteur 22 ou 32 définit une surface externe conductrice de l'électricité, notée S1 ou S2, qui est de forme annulaire. Ainsi, la surface externe S1 ou S2 s'étend à 360° autour de l'axe X. La surface externe S1 ou S2 peut avoir une forme de révolution. Le corps conducteur 22 ou 32 présente dans l'exemple illustré une forme torique. Le corps conducteur 22 ou 32 présente une forme en U lorsque la torche 1 est observée en coupe longitudinale.The anode 20 and the cathode 30 each comprise an electrically conductive body, respectively 22 and 32. Each conductive body 22 or 32 defines an electrically conductive outer surface, denoted S1 or S2, which is annular in shape. Thus, the outer surface S1 or S2 extends 360 ° about the X axis. The outer surface S1 or S2 can have a shape of revolution. The conductive body 22 or 32 has in the example illustrated a toroidal shape. The conductive body 22 or 32 has a U-shape when the torch 1 is observed in longitudinal section.

Chacune des surfaces externes S1 ou S2 est en communication avec la chambre 3 de génération du plasma. Ainsi, en fonctionnement, l'arc A électrique est généré entre la surface externe S1 et la surface externe S2. L'arc A comprend une partie centrale s'étendant au travers de la chambre 3 et des pieds PA d'arc reliant cette partie centrale à l'anode 20 et à la cathode 30.Each of the external surfaces S1 or S2 is in communication with the plasma generation chamber 3. Thus, in operation, the electric arc A is generated between the outer surface S1 and the outer surface S2. Arc A comprises a central portion extending through chamber 3 and arc feet PA connecting this central portion to anode 20 and cathode 30.

Une coupe plus détaillée de l'anode 20 est fournie à la figure 6. La cathode 30 présente une structure similaire.A more detailed section of anode 20 is provided at figure 6 . The cathode 30 has a similar structure.

Le corps conducteur 22 peut être en cuivre ou en alliage de cuivre. D'autres matériaux conducteurs de l'électricité sont envisageables pour constituer le corps conducteur 22. L'emploi de cuivre reste toutefois préférentiel afin d'optimiser la diffusion des calories dans le corps, et donc permettre d'augmenter davantage encore la durée de vie de l'électrode.The conductive body 22 may be copper or copper alloy. Other electrically conductive materials are conceivable to constitute the conductive body 22. The use of copper however remains preferential in order to optimize the diffusion of calories in the body, and thus to make it possible to further increase the service life. of the electrode.

Le corps conducteur 22 comporte, dans l'exemple illustré, deux parties distinctes 22a et 22b assemblées, par exemple par soudure, le long d'une surface d'assemblage 22c. Chaque partie 22a et 22b s'étend à 360° autour de l'axe X. Les parties 22a et 22b comprennent chacune un relief de positionnement 22d ou 22e destiné à coopérer avec un relief complémentaire, respectivement 53 ou 39 (voir figure 2), afin d'assurer le bon positionnement de l'électrode dans la torche 1. Les reliefs de positionnement 22d et 22e peuvent chacun avoir une forme annulaire et s'étendre autour de l'axe X. Les reliefs de positionnement 22d et 22e peuvent chacun s'étendre à 360° autour de l'axe X.The conductive body 22 comprises, in the illustrated example, two separate parts 22a and 22b assembled, for example by welding, along an assembly surface 22c. Each portion 22a and 22b extends 360 ° about the axis X. The portions 22a and 22b each comprise a positioning relief 22d or 22e intended to cooperate with a complementary relief, respectively 53 or 39 (see figure 2 ), to ensure the correct positioning of the electrode in the torch 1. The positioning reliefs 22d and 22e can each have an annular shape and extend around the axis X. The positioning reliefs 22d and 22e can each extend 360 ° around the X axis.

Le corps 22 conducteur définit un volume intérieur 23 dans lequel est présente une première bobine 24 de génération d'un champ magnétique. Le volume intérieur 23 peut lui aussi avoir une forme annulaire, et s'étendre à 360° autour de l'axe X.The conductive body 22 defines an internal volume 23 in which there is a first coil 24 for generating a magnetic field. The inner volume 23 may also have an annular shape, and extend 360 ° about the X axis.

La première bobine 24 comprend un enroulement d'un fil 26 conducteur de l'électricité positionné autour de la surface S1. Lors du fonctionnement, le fil 26 est traversé par un courant électrique permettant ainsi de générer un champ magnétique induit. Ce champ magnétique engendre une force permettant de faire tourner les pieds PA de l'arc électrique A autour de l'axe X. Cette rotation est matérialisée par la flèche R sur la figure 2.The first coil 24 comprises a winding of an electrically conductive wire 26 positioned around the surface S1. During operation, the wire 26 is traversed by an electric current thus making it possible to generate an induced magnetic field. This magnetic field generates a force making it possible to turn the feet PA of the electric arc A around the axis X. This rotation is materialized by the arrow R on the figure 2 .

Cette rotation permet de répartir l'érosion des électrodes due à l'arc électrique sur la surface externe du corps et, par conséquent, d'augmenter la durée de vie des électrodes. Un autre avantage résultant de cette durée de vie augmentée des électrodes est la possibilité d'utiliser un gaz oxydant pour générer le plasma. L'utilisation d'un gaz oxydant permet de limiter le coût d'utilisation de la torche 1 sur des applications tolérant la présence d'oxygène. On peut en particulier, si cela est souhaité, s'affranchir de l'utilisation d'hélium dans le gaz G, lequel présente un coût relativement élevé.This rotation makes it possible to distribute the erosion of the electrodes due to the electric arc on the external surface of the body and, consequently, to increase the lifetime of the electrodes. Another advantage resulting from this increased lifetime of the electrodes is the possibility of using an oxidizing gas to generate the plasma. The use of an oxidizing gas makes it possible to limit the cost of using the torch 1 on applications that tolerate the presence of oxygen. In particular, it is possible, if desired, to dispense with the use of helium in the gas G, which has a relatively high cost.

Le fil 26 peut être en cuivre ou en alliage de cuivre. D'autres matériaux conducteurs sont toutefois utilisables pour constituer le fil. Le fil 26 est présent sur un support 28 de bobine. Dans l'exemple illustré, le support 28 a une forme torique. Le support 28 présente une forme en U lorsque la torche 1 est observée en coupe longitudinale. L'enroulement du fil 26 reproduit la courbure du support 28. Dans l'exemple illustré, la première bobine 24 présente ainsi une forme en U lorsque la torche 1 est observée en coupe longitudinale.The wire 26 may be copper or copper alloy. Other conductive materials are however usable to form the wire. The wire 26 is present on a coil support 28. In the example illustrated, the support 28 has a toric shape. The support 28 has a U-shape when the torch 1 is observed in longitudinal section. The winding of the wire 26 reproduces the curvature of the support 28. In the example illustrated, the first coil 24 thus has a U shape when the torch 1 is observed in longitudinal section.

Le fil 26 s'étend à 360° autour de l'axe X. Le fil 26 est enroulé en spirale autour de l'axe X. Le fil 26 définit une première spirale 261 dans un premier plan P1 transversal à l'axe X et une deuxième spirale 263 dans un deuxième plan P2 transversal à l'axe X et décalé du premier plan P1 le long de cet axe (voir figure 7). Le fil 26 définit en outre une zone de transition 265 entre les première 261 et deuxième 263 spirales.The wire 26 extends 360 ° about the X axis. The wire 26 is wound in a spiral around the X axis. The wire 26 defines a first spiral 261 in a first plane P1 transverse to the X axis and a second spiral 263 in a second plane P2 transverse to the axis X and offset from the first plane P1 along this axis (see figure 7 ). The wire 26 further defines a transition zone 265 between the first 261 and second 263 spirals.

Lorsque l'on se déplace le long de l'enroulement formé par le fil 26, le rayon de cet enroulement est décroissant puis croissant. Le rayon de l'enroulement est décroissant dans la première région R1 puis croissant dans la deuxième région R2. Les première et deuxième régions sont décalées le long de l'axe X. On notera par ailleurs que la première bobine 24 peut ou non être symétrique par rapport à un plan P transversal à l'axe X.When moving along the winding formed by the wire 26, the radius of this winding is decreasing and increasing. The radius of the winding is decreasing in the first region R1 and then increasing in the second region R2. The first and second regions are shifted along the X axis. Note also that the first coil 24 may or may not be symmetrical with respect to a plane P transverse to the X axis.

La réalisation de l'anode 20, respectivement de la cathode 30, comprend le bobinage du fil 26, respectivement 36, sur le support 28, respectivement 38. Ce bobinage peut être réalisé dans un moule en forme de tore dont la section est en forme de U. Le bobinage est ensuite relié à deux bornes de connexion électrique. Les première 24 et deuxième 34 bobines ainsi obtenues sont alors figées et solidarisées au support par injection et durcissement d'une résine isolante de l'électricité.The embodiment of the anode 20, respectively of the cathode 30, comprises the winding of the wire 26, respectively 36, on the support 28, respectively 38. This winding can be performed in a toroid mold whose section is shaped The coil is then connected to two electrical connection terminals. The first 24 and second 34 coils thus obtained are then fixed and secured to the support by injection and hardening of an insulating resin of electricity.

L'exemple de torche 1 illustré comprend une unique anode 20 et une unique cathode 30. On ne sort toutefois pas du cadre de l'invention si la torche comprenait plusieurs anodes et/ou plusieurs cathodes.The illustrated example of torch 1 comprises a single anode 20 and a single cathode 30. However, it is not beyond the scope of the invention if the torch comprises several anodes and / or several cathodes.

Dans l'exemple illustré, l'anode 20 est située du côté du fond 50 et la cathode 30 du côté opposé à l'anode 20. La polarisation pourrait toutefois être inversée : la cathode serait dans ce cas positionnée du côté du fond 50 et l'anode du côté opposé à la cathode. Le contenu de cette description détaillée est aussi valable dans le cas où la polarisation est inversée.In the illustrated example, the anode 20 is located on the side of the bottom 50 and the cathode 30 on the side opposite the anode 20. The polarization could, however, be reversed: the cathode would in this case be positioned on the side of the bottom 50 and the anode on the opposite side to the cathode. The content of this detailed description is also valid in the case where the polarization is reversed.

Les première 24 et deuxième 34 bobines permettent d'améliorer notablement la durée de vie de l'anode 20 et de la cathode 30. Une autre caractéristique permettant d'améliorer davantage encore la durée de vie des électrodes est relative au circuit permettant le refroidissement de ces dernières durant le fonctionnement. Ce circuit de refroidissement va, à présent, être décrit pour l'anode 20, étant entendu que le refroidissement de la cathode 30 est opéré de manière similaire.The first 24 and second 34 coils can significantly improve the life of the anode 20 and the cathode 30. Another feature to further improve the life of the electrodes is relative to the circuit for cooling the these during operation. This cooling circuit will now be described for the anode 20, it being understood that the cooling of the cathode 30 is operated in a similar manner.

Le corps conducteur 22 présente une surface interne S3 au niveau de laquelle le refroidissement de l'anode 20 est destiné à être réalisé (voir figure 6). La surface interne S3 est en communication avec un orifice 46b d'introduction d'un fluide F de refroidissement. Le refroidissement est ainsi réalisé au plus près de l'arc A électrique ce qui permet d'optimiser son efficacité, et d'améliorer davantage encore la durée de vie des électrodes en limitant l'érosion due à l'arc électrique. La limitation de l'érosion due à l'arc est avantageuse, en particulier, dans le cas où la torche 1 est utilisée pour réaliser un dépôt d'un matériau par voie plasma afin de limiter la « pollution » du flux plasma, et donc du dépôt réalisé, par le matériau d'électrode érodé.The conductive body 22 has an internal surface S3 at which the cooling of the anode 20 is intended to be realized (see figure 6 ). The inner surface S3 is in communication with an orifice 46b for introducing a cooling fluid F. The cooling is thus carried out as close as possible to the electric arc A, which makes it possible to optimize its efficiency, and to further improve the service life of the electrodes by limiting the erosion due to the electric arc. The limitation of the erosion due to the arc is advantageous, in particular, in the case where the torch 1 is used to make a deposition of a material by plasma way in order to limit the "pollution" of the plasma flux, and therefore deposition performed by the eroded electrode material.

La torche 1 comprend au moins un port 46 d'introduction d'un fluide F de refroidissement au niveau de chacune des électrodes 20 et 30.The torch 1 comprises at least one port 46 for introducing a cooling fluid F at each of the electrodes 20 and 30.

Le port 46 comprend une entrée 46a qui est reliée à une source de fluide de refroidissement (non représentée) et une sortie 46b débouchant à l'intérieur du corps 22. La sortie 46b débouche dans le volume intérieur 23 du corps 22.Port 46 comprises an inlet 46a which is connected to a source of cooling fluid (not shown) and an outlet 46b opening inside the body 22. The outlet 46b opens into the internal volume 23 of the body 22.

Dans l'exemple illustré, le port 46 est formée de deux parties distinctes, à savoir : une première partie 48 définissant l'entrée 46a et une deuxième partie 47 définissant la sortie 46b et insérée à l'intérieur de la première partie 48. En variante, le port 46 pourrait être formé d'une seule et même pièce.In the example illustrated, the port 46 is formed of two distinct parts, namely: a first portion 48 defining the inlet 46a and a second portion 47 defining the outlet 46b and inserted inside the first portion 48. Alternatively, the port 46 could be formed of a single piece.

La torche 1 comprend en outre au moins un port de sortie d'un fluide F de refroidissement au niveau de chacune des électrodes 20 et 30. Le port de sortie situé au niveau de l'anode 20 est noté 40 et le port situé au niveau de la cathode 30 est noté 140 (voir figure 3). Le port 40 comprend une entrée 40a en communication avec le volume intérieur 23 et une sortie 40b en communication avec un système d'évacuation du fluide de refroidissement (non représenté).The torch 1 further comprises at least one output port of a cooling fluid F at each of the electrodes 20 and 30. The output port located at the anode 20 is noted 40 and the port located at the level of the cathode 30 is noted 140 (see figure 3 ). Port 40 includes an inlet 40a in communication with the interior volume 23 and an outlet 40b in communication with a cooling fluid discharge system (not shown).

Le port 40 et le port 46 peuvent ou non être positionnés symétriquement par rapport à l'axe X.Port 40 and port 46 may or may not be positioned symmetrically with respect to the X axis.

En fonctionnement, le fluide F de refroidissement est introduit dans le volume intérieur 23 au travers du port 46. Le fluide F circule alors dans le volume intérieur 23. Le fluide F est au contact de la surface interne S3 afin de réaliser le refroidissement du corps 22 ou 32. On notera en effet la présence d'un espace e entre la bobine 24 et la surface interne S3 permettant au fluide F de refroidissement de circuler. En d'autres termes, la bobine 24 est située à une distance non nulle du corps 22. Cette distance peut typiquement être inférieure ou égale à 3 mm.In operation, the cooling fluid F is introduced into the internal volume 23 through the port 46. The fluid F then circulates in the internal volume 23. The fluid F is in contact with the inner surface S3 in order to achieve the cooling of the body 22 or 32. It will be noted indeed the presence of a space e between the coil 24 and the inner surface S3 allowing the cooling fluid F to circulate. In other words, the coil 24 is located at a non-zero distance from the body 22. This distance can typically be less than or equal to 3 mm.

Une fois que le fluide F de refroidissement a traversé le volume intérieur 23, ce dernier est évacué à l'extérieur de la torche 1 au travers du port 40.Once the cooling fluid F has passed through the internal volume 23, the latter is evacuated outside the torch 1 through the port 40.

Le trajet du fluide F de refroidissement dans le corps 22 est matérialisé, à la figure 6, par les flèches F.The path of the cooling fluid F in the body 22 is materialized, at the figure 6 , by the arrows F.

Comme il vient d'être décrit plus haut, la présence des bobines et du circuit de refroidissement des électrodes participe avantageusement à augmenter la durée de vie de ces dernières. La description qui suit s'attache à détailler un autre aspect de l'exemple de torche 1 illustré, relatif à la buse d'éjection 80.As has just been described above, the presence of the coils and the electrode cooling circuit advantageously contributes to increasing the service life of the latter. The following description sets out to detail another aspect of the example of torch 1 illustrated, relating to the ejection nozzle 80.

La buse d'éjection 80 est située en aval de l'anode 20 et de la cathode 30. Le plasma est destiné à être distribué à l'extérieur de la torche 1 au travers de la buse d'éjection (flux plasma FP à la figure 2). La buse d'éjection 80 définit un canal 81 d'éjection du plasma en communication avec la chambre 3. Le canal 81 s'étend le long de l'axe X. Le canal 81 débouche à l'extérieur de la torche 1 au travers de l'orifice 88 de sortie.The ejection nozzle 80 is situated downstream of the anode 20 and the cathode 30. The plasma is intended to be distributed outside the torch 1 through the ejection nozzle (FP plasma stream). figure 2 ). The ejection nozzle 80 defines a plasma ejection channel 81 in communication with the chamber 3. The channel 81 extends along the axis X. The channel 81 opens out of the torch 1 through of the outlet port 88.

La buse 80 d'éjection illustrée présente une forme de tuyère. La buse d'éjection 80 comprend ainsi un convergent 82 situé du côté de la chambre 3, un divergent 86 situé du côté de l'orifice 88 de sortie et un col 84 situé entre le convergent 82 et le divergent 86. La section du convergent 82 du côté de la chambre 3 est supérieure à la section du convergent 82 du côté de l'orifice 88. La section du divergent 86 du côté de la chambre 3 est inférieure à la section du divergent 86 du côté de l'orifice 88.The ejection nozzle 80 shown has a nozzle shape. The ejection nozzle 80 thus comprises a convergent 82 located on the side of the chamber 3, a diverging 86 located on the side of the outlet orifice 88 and a collar 84 between the convergent 82 and the divergent 86. The section of the convergent 82 on the side of the chamber 3 is greater than the section of the convergent 82 on the side of the orifice 88. The section of the divergent 86 on the side of the chamber 3 is less than the section of the divergent 86 on the side of the orifice 88.

Dans une variante non illustrée, la buse d'éjection peut uniquement comporter un convergent et être dépourvue de divergent.In a variant not shown, the ejection nozzle can only have a convergent and be devoid of divergent.

Il apparaîtra clairement à l'homme du métier que la forme du canal d'éjection 81 est déterminée en fonction de l'application envisagée pour la torche 1 à plasma. Il fait partie des connaissances générales de l'homme du métier d'adapter la forme de ce canal 81 à l'application souhaitée.It will be clear to those skilled in the art that the shape of the ejection channel 81 is determined according to the intended application for the plasma torch 1. It is part of the general knowledge of those skilled in the art to adapt the shape of this channel 81 to the desired application.

Comme décrit précédemment pour les segments 13 et les électrodes 20 et 30, la buse d'éjection 80 est elle aussi munie d'un circuit de refroidissement.As previously described for the segments 13 and the electrodes 20 and 30, the ejection nozzle 80 is also provided with a cooling circuit.

Ainsi, la buse d'éjection 80 définit un volume intérieur 92 dans lequel un fluide de refroidissement est destiné à circuler. Ce volume intérieur 92 peut s'étendre à 360° autour de l'axe X. Le volume intérieur 92 peut être situé autour du canal d'éjection 81.Thus, the ejection nozzle 80 defines an interior volume 92 in which a cooling fluid is intended to circulate. This interior volume 92 may extend 360 ° about the axis X. The interior volume 92 may be located around the ejection channel 81.

La figure 3 illustre les détails du système de refroidissement de la buse 80. La torche 1 peut comprendre au moins un port 90 d'introduction d'un fluide F de refroidissement débouchant dans le volume intérieur 92. Le port 90 comprend une entrée 90a qui est reliée à une source de fluide de refroidissement (non représentée) et une sortie 90b débouchant dans le volume intérieur 92.The figure 3 illustrates the details of the cooling system of the nozzle 80. The torch 1 may comprise at least one port 90 for introducing a cooling fluid F opening into the internal volume 92. The port 90 comprises an inlet 90a which is connected to a coolant source (not shown) and an outlet 90b opening into the interior volume 92.

La torche 1 peut en outre comprendre au moins un port 94 de sortie du fluide F de refroidissement en communication avec le volume intérieur 92. Le port 94 et le port 90 peuvent ou non être positionnés symétriquement par rapport à l'axe X. Le port 94 comprend une entrée 94a en communication avec le volume intérieur 92 et une sortie 94b reliée à un système d'évacuation du fluide de refroidissement (non représenté).The torch 1 may further comprise at least one port 94 for outputting the cooling fluid F in communication with the interior volume 92. The port 94 and the port 90 may or may not be positioned symmetrically with respect to the X axis. 94 includes an inlet 94a in communication with the interior volume 92 and an outlet 94b connected to a cooling fluid discharge system (not shown).

En fonctionnement, le fluide F de refroidissement est introduit dans le volume intérieur 92 au travers du port 90. Le fluide F de refroidissement traverse alors le volume intérieur 92 afin de réaliser le refroidissement de la buse d'éjection 80. Le fluide F de refroidissement est ensuite évacué au travers du port 94 de sortie. Le trajet du fluide de refroidissement dans le volume intérieur 92 est matérialisé par les flèches F sur la figure 3.In operation, the cooling fluid F is introduced into the internal volume 92 through the port 90. The cooling fluid F then passes through the internal volume 92 in order to carry out the cooling of the ejection nozzle 80. The cooling fluid F is then evacuated through the output port 94. The fluid path of cooling in the interior volume 92 is indicated by the arrows F on the figure 3 .

La buse d'éjection 80 peut être fixée de manière amovible au reste de la torche 1 comprenant l'anode 20 et la cathode 30. Cela permet avantageusement de modifier l'élément de mise en forme de l'écoulement afin d'adapter un même système à différentes applications. On notera toutefois que la présence d'une buse d'éjection demeure optionnelle.The ejection nozzle 80 may be removably attached to the remainder of the torch 1 comprising the anode 20 and the cathode 30. This advantageously makes it possible to modify the flow forming element in order to adapt the same system to different applications. Note however that the presence of an ejection nozzle remains optional.

Dans une variante non illustrée, la torche peut comporter au moins un canal d'introduction d'un matériau à déposer par procédé plasma débouchant en aval de la chambre de génération du plasma. Une telle variante est adaptée à des applications où la torche est utilisée pour réaliser un revêtement sur un substrat par procédé plasma. Dans ce cas, le matériau est introduit dans le flux de plasma généré afin d'être déposé sur le substrat. Le canal d'introduction peut déboucher en aval de l'anode et de la cathode. Le canal d'introduction peut déboucher entre une électrode et la buse d'éjection. Le canal d'introduction peut en variante déboucher en aval de la buse d'éjection.In a variant that is not illustrated, the torch may comprise at least one introduction channel of a material to be deposited by a plasma process opening downstream of the plasma generation chamber. Such an alternative is suitable for applications where the torch is used to effect a coating on a substrate by plasma process. In this case, the material is introduced into the generated plasma stream in order to be deposited on the substrate. The introduction channel may open downstream of the anode and the cathode. The introduction channel may open between an electrode and the ejection nozzle. The introduction channel may alternatively lead downstream of the ejection nozzle.

L'invention n'est toutefois pas limitée à l'utilisation de la torche pour la réalisation d'un revêtement par procédé plasma. On pourrait, en variante, générer un plasma à l'aide de la torche que l'on appliquerait au niveau d'un bouclier thermique d'une sonde spatiale par exemple, afin d'évaluer son comportement en conditions de rentrée atmosphérique.The invention is however not limited to the use of the torch for producing a plasma coating. One could, alternatively, generate a plasma using the torch that would be applied at a heat shield of a space probe, for example, to evaluate its behavior under atmospheric reentry conditions.

On a représenté à la figure 8 un schéma électrique simplifié montrant un premier système électrique 203 dans lequel le corps 22 de l'anode 20 et le corps 32 de la cathode 30 sont reliés en série aux bornes d'un premier générateur électrique GE1. Le premier système électrique 203 permet d'assurer la formation du plasma.We have shown figure 8 a simplified electrical diagram showing a first electrical system 203 in which the body 22 of the anode 20 and the body 32 of the cathode 30 are connected in series across a first electrical generator GE1. The first electrical system 203 makes it possible to ensure the formation of the plasma.

La figure 8 montre en outre un deuxième système électrique 205 dans lequel les première 24 et deuxième 34 bobines sont reliées en série aux bornes d'un deuxième générateur électrique GE2. Le deuxième système électrique 205 permet d'assurer la création du champ magnétique induit permettant de faire tourner l'arc électrique et de prolonger ainsi la durée de vie des électrodes.The figure 8 further shows a second electrical system 205 in which the first 24 and second 34 coils are connected in series across a second electrical generator GE2. The second electrical system 205 ensures the creation of the induced magnetic field to rotate the electric arc and thus prolong the life of the electrodes.

En fonctionnement, on peut imposer entre l'anode 20 et la cathode 30 une tension comprise entre 150 V et 400 V, par exemple comprise entre 200 V et 300 V. L'intensité du courant circulant entre l'anode 20 et la cathode 30 peut être inférieure ou égale à 200 A. L'intensité du courant circulant dans les première et deuxième bobines 24 et 34 peut être inférieure ou égale à 200 A.In operation, it is possible to impose between the anode 20 and the cathode 30 a voltage of between 150 V and 400 V, for example between 200 V and 300 V. The intensity of the current flowing between the anode 20 and the cathode 30 may be less than or equal to 200 A. The intensity of the current flowing in the first and second coils 24 and 34 may be less than or equal to 200 A.

L'expression « compris(e) entre ... et ... » doit se comprendre comme incluant les bornes.The expression "understood between ... and ..." must be understood as including boundaries.

Claims (13)

  1. A plasma torch (1) comprising at least:
    - a chamber (3) for generating a plasma inside which at least one channel (5) emerges for injecting a pressurized gas (G),
    - an anode (20) and a cathode (30) situated on either side of the chamber (3) for generating the plasma and each comprising a body (22; 32) conducting electricity having an annular outer conducting surface (S1; S2) in communication with the plasma-generating chamber (3), and
    - a first (24) and a second (34) coil for generating a magnetic field, the first coil (24) being present inside the body (22) of the anode (20) and the second coil (34) being present inside the body (32) of the cathode (30), each of the first (24) and second (34) coils comprising a winding of a wire (26; 36) which is electrically conductive and positioned around the conductive surface (S1; S2) of the associated body, characterized by each of the first and second coils having a U shape in longitudinal section.
  2. The torch according to claim 1, wherein each conductive body (22; 32) has an inner surface (S3) in communication with an orifice (46b) for introducing a coolant fluid (F).
  3. The torch (1) according to claim 1 or 2, wherein each conductive body (22; 32) has a toroidal shape.
  4. The torch (1) according to claim 3, wherein each of the first (24) and second (34) coils is carried by a coil support (28; 38) having a toroidal shape.
  5. The torch (1) according to any one of claims 1 to 4, wherein the torch comprises a single cathode (30) and a single anode (20).
  6. The torch according to any one of claims 1 to 5, wherein each conductive body (22; 32) is made from copper or a copper alloy.
  7. The torch (1) according to any one of claims 1 to 6, wherein the plasma-generating chamber (3) is defined by at least one tubular neutrode segment (13).
  8. The torch according to any one of claims 1 to 7, wherein the plasma-generating chamber (3) is defined by at least a first and a second tubular segment (13) connected to one another removably.
  9. The torch according to claim 8, wherein the gas injection channel (5) is defined between the first and second segments (13).
  10. The torch according to any one of claims 1 to 9, wherein the torch further comprises a plasma discharge nozzle (80) located downstream from the anode (20) and the cathode (30).
  11. An assembly usable to generate plasma comprising at least:
    - a plasma torch (1) according to any one of claims 1 to 10, and
    - a pressurized gas (G) source in communication with the injection channel (5).
  12. The assembly according to claim 11, wherein the pressurized gas (G) is a pressurized oxidizing gas.
  13. The assembly according to claim 11, wherein the pressurized gas (G) is a pressurized neutral gas.
EP18162465.1A 2017-03-30 2018-03-19 Plasma torch Active EP3383145B1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR1752665A FR3064876B1 (en) 2017-03-30 2017-03-30 PLASMA TORCH

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EP3383145A1 EP3383145A1 (en) 2018-10-03
EP3383145B1 true EP3383145B1 (en) 2019-06-19

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP4044772A4 (en) * 2019-10-02 2023-06-21 Korea Hydro & Nuclear Power Co., Ltd Plasma torch

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114158173B (en) * 2021-11-30 2023-09-01 西北核技术研究所 Silk array load structure for inhibiting pre-pulse current

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3343019A (en) * 1964-03-06 1967-09-19 Westinghouse Electric Corp High temperature gas arc heater with liquid cooled electrodes and liquid cooled chamber walls
US3445191A (en) * 1965-07-14 1969-05-20 Westinghouse Electric Corp Arc heater apparatus for chemical processing
US3629553A (en) * 1969-01-10 1971-12-21 Westinghouse Electric Corp Recurrent arc heating process
US3663792A (en) * 1970-03-02 1972-05-16 Westinghouse Electric Corp Apparatus and method of increasing arc voltage and gas enthalpy in a self-stabilizing arc heater
US3832519A (en) * 1972-08-11 1974-08-27 Westinghouse Electric Corp Arc heater with integral fluid and electrical ducting and quick disconnect facility
USH587H (en) * 1987-10-13 1989-02-07 The United States Of America As Represented By The Secretary Of The Air Force Dual toroidal electrodes

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
None *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP4044772A4 (en) * 2019-10-02 2023-06-21 Korea Hydro & Nuclear Power Co., Ltd Plasma torch
US12022600B2 (en) 2019-10-02 2024-06-25 Korea Hydro & Nuclear Power Co., Ltd. Plasma torch

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FR3064876A1 (en) 2018-10-05
EP3383145A1 (en) 2018-10-03
FR3064876B1 (en) 2019-12-27

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