Electric arc blast nozzle

Abstract

To provide an electric arc blast nozzle that avoids or at least reduces the risk of partial discharge. [Solution] The present invention relates to an electric arc blast nozzle 10 having an internal housing 12 that extends along a longitudinal axis and encloses an internal space 13. The internal housing is particularly configured to house the electrical contacts 24, 25 of a circuit breaker. When used in a circuit breaker, the electric arc blast nozzle can move longitudinally L with respect to one of the electrical contacts and the other. According to the present invention, the internal housing of the electric arc blast nozzle is closely covered by at least one outer layer 32 having a reinforcing layer 33. In doing so, gas-filled gaps and cavities between the at least one outer layer and the internal housing are avoided, which reduces the risk of partial discharge.

Description

Technical Field

[0001] The present invention relates to an electric arc blast nozzle specifically configured for use in a high voltage circuit breaker. Such a high voltage circuit breaker can be used to interrupt the electrical connection of an electric wire, whereby a voltage within the range of more than about 50 kV and up to 800 kV is applied between the contacts of the circuit breaker.

Background Art

[0002] Circuit breakers are known in many different configurations. For example, Korean Patent Publication No. 1020190110842 discloses an ultra-high voltage circuit breaker having a fixed arc contact and a movable arc contact. It compresses a main nozzle connected to the distal end of a cylinder provided to move the movable arc contact. A nozzle support member is partially inserted into a notch of the main nozzle to improve mechanical strength.

[0003] Japanese Patent Application Laid-Open No. 2021051945 relates to a gas circuit breaker in which a cylinder is disposed within a container filled with an insulating gas. When a movable contact moves axially toward a fixed contact, the insulating gas jets out and extinguishes an arc generated between the movable contact and the fixed contact. One end of the cylinder housing is connected to a nozzle portion that at least partially surrounds the movable contact.

[0004] A gas blast circuit breaker is known from Japanese Patent Application Laid-Open No. 2018116852. A nozzle portion at least partially surrounds a movable electrical contact. In the nozzle portion, a material with high mechanical strength is arranged so as not to directly contact an insulating gas flowing through the nozzle portion for extinguishing an electric arc.

[0005] A circuit breaker having a nozzle is disclosed in International Publication No. 95 / 33274. A plastic tube partially surrounds the nozzle and is provided to avoid the radial spread of the nozzle. The plastic tube can be made of a fiber reinforced composite plastic.

[0006] European Patent Application Publication No. 3479390 describes an electric arc blast nozzle comprising a plurality of parts arranged adjacent to each other in the longitudinal direction, namely two ends and a central neck-forming portion positioned between the two ends. To secure these three parts, the housing may be surrounded by a sheath made of a dielectric material such as polytetrafluoroethylene. [Overview of the project]

[0007] When an electric arc blast nozzle is assembled from multiple non-uniform parts, an electric field strength is generated, which can lead to partial discharge. It may be an objective of the present invention to provide an electric arc blast nozzle that avoids or at least reduces the risk of partial discharge.

[0008] This objective is achieved by an electric arc blast nozzle having the features of claim 1.

[0009] The electric arc blast nozzle according to the present invention is configured for use in a high-voltage circuit breaker. For example, a high-voltage circuit breaker may be configured to electrically isolate the voltage between its two electrical contacts in the range of 52kV to 800kV.

[0010] An electric arc blast nozzle comprises an internal housing extending along a longitudinal axis. The direction parallel to the longitudinal axis is referred to as the longitudinal direction. The internal housing comprises a first nozzle end section, a second nozzle end section, and an intermediate nozzle section positioned between them. The internal housing encloses an internal space through which an insulating gas can flow to extinguish the electric arc. The insulating gas may be any suitable gas used or known for this purpose, such as a mixture of one of the aforementioned gases, optionally containing at least one of the following components: sulfur hexafluoride (SF6), carbon dioxide (CO2), nitrogen (N2), dioxygen (O2), and fluoronitrile (e.g., C4-PFN) and fluoroketone (e.g., C5-PFK).

[0011] The internal housing may include a dielectric material, or a combination of two or more dielectric materials. It may include, or consist of, at least one of polytetrafluoroethylene (PTFE), polymer, glass, or porcelain. For example, glass, in particular, can be used as a filler in combination with other materials.

[0012] The electric arc blast nozzle according to the present invention comprises at least one outer layer. The outer layer, or at least one of the outer layers, is applied directly to the outer surface of the inner housing and may be referred to as the innermost layer. The outer layer, or at least one of the outer layers, is a reinforcing layer. The reinforcing layer may contain, or consist of, at least one of the following materials: a synthetic resin, preferably an epoxy resin, a modified epoxy resin containing at least one viscosity-reducing reactive diluent, a polymer material, or a ceramic material. The epoxy resin may be fluorinated or not. Optionally, reinforcing fibers may be embedded in a matrix containing one of the indicated materials.

[0013] The material of the reinforcing layer preferably has a lower density compared to the material of the inner housing. For example, when a synthetic resin such as epoxy resin is used for the reinforcing layer, its density is less than 50% compared to the density of the inner housing made from polytetrafluoroethylene (PTFE).

[0014] Therefore, the configuration according to the present invention also has the advantage of reducing the weight of the electric arc blast nozzle. The electric arc blast nozzle provides high mechanical strength. Furthermore, the environmental impact of the electric arc blast nozzle according to the present invention is smaller than that of conventional electric arc blast nozzles. The use of environmentally hazardous materials such as polytetrafluoroethylene is reduced and may be replaced with materials that are less hazardous or harmful to the environment, for example, by reducing the use of perfluoroalkyl compounds and polyfluoroalkyl compounds (PFAS) used in electric arc blast nozzles.

[0015] The outer surface of the inner housing may undergo surface treatment before the application of the outer layer, or one of the outer layers. Such surface treatment may include chemical and / or electrochemical and / or thermal and / or physical surface treatment processes, such as cleaning, pickling, etching, conversion layer formation, shot peening, or sandblasting. This treatment may prepare the outer surface of the inner housing for the subsequent application of the outer layer, or the innermost layer of the outer layer. For example, if the inner housing contains fluorine (e.g., polytetrafluoroethylene), an etching process may remove fluorine at least on the outer surface of the housing, and possibly to a certain depth from the outer surface of the housing. This improves continuous two-dimensional close contact between the adjacent (innermost) outer layer and the outer surface of the inner housing.

[0016] The outer layer directly adjacent to the outer surface of the inner housing is applied to the outer surface of the inner housing in tight two-dimensional contact. In particular, there are no gas-containing gaps or cavities in the contact area between the outer housing surface and the adjacent outer layer, which could affect the electric field resulting in partial discharge (PD). If gas-containing gaps or cavities are present, the gas has a volume and size that is too small to affect the electric field in a manner that results in partial discharge (PD) at that location.

[0017] Therefore, according to the present invention, a close connection is provided between the outer surface of the housing and the directly adjacent (innermost) outer layer. For example, this can be achieved by forming at least one outer layer on the outer surface of the housing using an overmolding method or any other known suitable method.

[0018] The number of outer layers may vary. At least one reinforcing layer, in particular, may be provided, or only one reinforcing layer. As an option in addition to the at least one reinforcing layer, one or more additional outer layers may be provided, such as one or more insulating layers to increase the dielectric strength of the electric arc blast nozzle. The at least one insulating layer may include at least one of the following materials: polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), any other polymer material, glass, or porcelain.

[0019] Preferably, at least one outer layer, particularly an outer layer adjacent to the outer surface of the housing, is attached to the outer surface of the housing by material bonding.

[0020] For example, at least one outer layer can be attached to the outer surface of the housing during its fabrication by multi-component molding, such as multi-component injection molding. For example, the inner housing can be placed in a mold, and then at least one outer layer can be fabricated.

[0021] If two or more outer layers are to be provided, first an outer layer directly adjacent to the outer surface of the housing can be manufactured (e.g., molded), and then one or more additional outer layers can be manufactured (e.g., molded) in a desired order.

[0022] The reinforcing layer and / or any other optional outer layer may extend longitudinally over at least the first nozzle end section, but leaving at least a portion of the intermediate nozzle section and the second nozzle end section uncovered. Optionally, at least one outer layer, in particular the reinforcing layer, may completely cover the first nozzle end section, or may extend longitudinally over the intermediate nozzle section partially or entirely, but leaving at least a portion of the second nozzle end section and optionally the intermediate nozzle section uncovered. In another optional embodiment, at least one outer layer, in particular the reinforcing layer, may completely cover the first nozzle end section and the intermediate nozzle section, or may extend longitudinally over the second nozzle end section partially or entirely. In one embodiment, at least one outer layer, in particular the reinforcing layer, covers the entire longitudinal surface of the housing of the internal housing from one end to the other.

[0023] In all of these embodiments, at least one outer layer may preferably extend continuously in the circumferential direction around the longitudinal axis (e.g., in a ring or sleeve shape) without any interruptions (holes, cavities, slots, etc.).

[0024] By providing a reinforcing layer at least partially around the internal housing, the wall thickness of the internal housing can be reduced, at least in the area where the reinforcing layer is present. The wall thickness can be reduced by at least about 5%, 10%, or 15% compared to embodiments in which the internal housing does not have an external reinforcing layer. There are no gas (especially air) filled gaps or cavities that could significantly disturb or affect the electric field due to close contact between adjacent outer layers and the outer surface of the housing, and between two adjacent outer layers where applicable. This reduces, and at least largely eliminates, the risk of partial discharge.

[0025] Preferred embodiments of the present invention are disclosed in the dependent claims, specification, and drawings. Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

Brief Description of the Drawings

[0026] [Figure 1] It is a figure showing one embodiment of an electric arc blast nozzle having an inner housing and at least one outer layer provided on the outer surface of the housing of the inner housing. [Figure 2] It is a figure showing one embodiment of an electric arc blast nozzle having an inner housing and at least one outer layer provided on the outer surface of the housing of the inner housing. [Figure 3] It is a figure showing one embodiment of an electric arc blast nozzle having an inner housing and at least one outer layer provided on the outer surface of the housing of the inner housing. [Figure 4] It is a figure showing one embodiment of an electric arc blast nozzle having an inner housing and at least one outer layer provided on the outer surface of the housing of the inner housing. [Figure 5] It is a schematic diagram of two parts assembled together according to the prior art. [Figure 6] It is a schematic diagram of a part of the outer surface of the inner housing and the housing where adjacent outer layers are provided in continuous and dense two-dimensional contact. [Figure 7] It is a basic schematic diagram of a high-voltage circuit breaker equipped with an electric arc blast nozzle according to the present invention.

Embodiments for Carrying Out the Invention

[0027] In FIGS. 1 to 4, different embodiments of an electric arc blast nozzle 10 that can be used in a high-voltage circuit breaker 11 highly schematically shown in FIG. 7 are shown.

[0028] The electric arc blast nozzle 10 includes an inner housing 12 extending along the longitudinal axis X. The direction parallel to the longitudinal axis X is referred to as the longitudinal direction L.

[0029] The internal housing 12 encloses a volume or inner space 13 that extends continuously through the internal housing 12 from the first axial end 14 to the second axial end 15 when viewed from the longitudinal direction L. In the circumferential direction about the longitudinal axis X, the internal housing 12 completely encloses the inner space 13.

[0030] As is clear from Figures 1 to 4, the internal housing 12 comprises a plurality of parts or sections adjacent to each other in the longitudinal direction L. These parts or sections may consist of at least two individual parts connected to each other, or they may be realized as a monolithic housing body.

[0031] The internal housing 12 has a first nozzle end section 16 having a first axial end 14 and a second nozzle end section 17 having a second axial end 15 of the internal housing 12. Viewed from the longitudinal direction L, an intermediate nozzle section 18 is positioned between the two nozzle end sections 16 and 17, connecting the first nozzle end section 16 to the second nozzle end section 17.

[0032] The internal space 13 has a reduced cross-sectional area or diameter within the intermediate nozzle section 18 compared to the adjacent first nozzle end section 16 and second nozzle end section 17. Thus, the intermediate nozzle section forms a neck section within the internal housing 12.

[0033] Optionally, an insert 19, particularly a ring-shaped or sleeve-shaped insert, may be placed in the intermediate nozzle section 18 directly adjacent to the inner space 13. The insert 19 can be made from a material with higher dielectric strength compared to the material of the intermediate nozzle section 18. The insert may include at least one of fluorocarbon polymer materials such as polytetrafluoroethylene (PTFE), ceramic materials, sulfur, graphite, mica, glass, and fluoride.

[0034] This insert 19 is an optional feature and may be provided or omitted in any embodiment of the electric arc blast nozzle 10, as shown in Figures 1 to 3.

[0035] In the first nozzle end section 16 and / or the second nozzle end section 17, the cross-sectional area of ​​the inner space 13 may increase continuously and / or stepwise in the longitudinal direction L and away from the intermediate nozzle section 18 (i.e., away from the intermediate nozzle section 18 toward the first axial end 14 or the second axial end 15, respectively). As illustrated, the cross-sectional area of ​​the inner space 13 can be constant along the first nozzle end section 16, thereby creating a step in the inner space 13 at the transition point between the first nozzle end section 16 and the intermediate nozzle section 18. In this embodiment, this step is provided by the face of the intermediate nozzle section 18. As also illustrated in Figures 1 to 4, starting from the intermediate nozzle section 18, the cross-sectional area of ​​the inner space 13 can increase continuously along the tapered section of the second nozzle end section 17, and may have a constant cross-sectional area between the tapered section and the second axial end 15.

[0036] The specific dimensions and shapes of the internal housing 12, particularly the first nozzle end section 16, the second nozzle end section 17, and the intermediate nozzle section 18, may vary and may be modified compared to the examples in Figures 1 to 4.

[0037] The first nozzle end section 16 and / or the second nozzle end section 17 and / or the intermediate nozzle section 18 may be made of different materials. For example, the first nozzle end section 16 may contain a fluorocarbon polymer matrix, such as a polytetrafluoroethylene matrix, which can be combined with a certain amount of inorganic material. For the intermediate nozzle section 18 and / or the second nozzle end section 17, other materials may be used, compared to the material of the first nozzle end section 16, such as polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), any other polymer material, glass, or porcelain.

[0038] In the embodiment schematically shown in Figure 4, the internal housing 12 can be a monolithic body, and the first nozzle end section 16, the second nozzle end section 17, and the intermediate nozzle section 18 are made of the same material and form sections of a single monolithic internal housing body.

[0039] As is particularly evident from Figures 1 to 4 and Figure 7, the two nozzle end sections 16 and 17 are configured to receive electrical contacts. Specifically, the first electrical contact 24 may protrude into the inner space 13 within the first nozzle end section 16, and the second electrical contact 25 may protrude into the inner space 13 within the second nozzle end section 17. In this embodiment, the first electrical contact 24 is configured as a movable contact that is displaceable in the longitudinal direction L together with the electric arc blast nozzle 10 toward and away from the second electrical contact 25. In the illustrated embodiment, the first electrical contact 24 is a female contact, and the second electrical contact 25 is a male contact.

[0040] The operation of the circuit breaker 11 is evident from the basic schematic diagram in Figure 7. When the two electrical contacts 24, 25 are close to each other or separated from each other, an electric arc EA is generated, as when the two electrical contacts 24, 25 are positioned far apart from each other, but the distance between the two electrical contacts 24, 25 is insufficient for the surrounding gas atmosphere to electrically insulate the two electrical contacts 24, 25 from each other. Electrical arc formation is undesirable because the electric arc EA maintains the electrical connection between the two electrical contacts 24, 25 even when such an electrical connection is still undesirable or no longer desirable. To assist in the extinguishing of the electric arc EA, the circuit breaker 11 is equipped with a gas flow generator 26. For example, the gas flow generator 26 may comprise at least one piston 27 movably positioned within a cylinder chamber 28 adjacent to or surrounding the first electrical contact 24.

[0041] The gas flow generator 26 generates a gas flow G within and along the inner space 13, which can extinguish the electric arc EA generated between the two electrical contacts 24 and 25. In the illustrated embodiment, the gas flow G flows from the gas flow generator 26 around the first electrical contact 24 in the inner space 13, and further downstream into the intermediate nozzle section 18, thereby flowing through the area between the two electrical contacts 24 and 25 and extinguishing the generated electric arc EA. The gas can then flow downstream from the intermediate nozzle section 18 into the second nozzle end section 17 and exit from the inner nozzle housing 12.

[0042] As shown in Figure 7 and described above, the gas flow G occurs, for example, when the two electrical contacts 24 and 25 move away from each other. On the other hand, when the two electrical contacts 24 and 25 move closer to each other, the direction of the gas flow G may be in the opposite direction.

[0043] According to the present invention, at least one outer layer 32 is provided on the inner housing 12. The at least one outer layer 32 comprises at least a reinforcing layer 33. Optionally, one or more additional outer layers 32, such as an insulating layer 34, may be provided to increase dielectric strength. However, in any embodiment of the electric arc blast nozzle 10, one reinforcing layer 33 is sufficient, and additional outer layers 32 may be omitted.

[0044] In the longitudinal direction L, at least one outer layer 32, in particular a reinforcing layer 33, may extend along the entire length of the inner housing 12, i.e., from the first axial end 14 to the second axial end 15 (Figures 1 and 4).

[0045] In modified embodiments, at least one outer layer 32, in particular a reinforcing layer 33, may be shorter than the internal housing 12 in the longitudinal direction L. Embodiments for such configurations are illustrated in Figures 2 and 3, where at least one outer layer 32 extends in the longitudinal direction L, at least across the first nozzle end section 16 and partially (Figure 3) or entirely across the intermediate nozzle section 18. As is evident from Figures 2 and 3, the second nozzle end section 17 may be left uncovered.

[0046] In the modified embodiments shown in Figures 2 and 3, one of the outer layers 32 (e.g., the insulating layer 34) may have a longer extension in the longitudinal direction L than at least one of the other outer layers 32 (e.g., the reinforcing layer 33). Such embodiments are illustrated schematically in Figure 3, where the longer extension of the insulating layer 34 is indicated by a dashed line. In this example, the insulating layer 34 extends across the entire inner housing 12 from the first axial end 14 to the second axial end 15, while the reinforcing layer 33 is shorter in the longitudinal direction L, extending from the first axial end 14 to at least the first nozzle end section 16, and partially, or as a further alternative, entirely, across the intermediate nozzle section 18.

[0047] Apart from the extension of at least one outer layer 32 in the longitudinal direction L, the embodiments shown in Figures 2 and 3 correspond to the embodiment shown in Figure 1, and therefore the detailed description of the electric arc blast nozzle 10 and the circuit breaker 11 applies similarly.

[0048] In the embodiment shown in Figure 4, insert 19 is omitted. Omitting insert 19 can be achieved in any embodiment of the electric arc blast nozzle, particularly in the embodiments shown in Figures 1 to 3.

[0049] In embodiments of the arc blast nozzle 10, the internal housing 12 may be implemented as a monolithic body as described above, and may be implemented in any embodiment of the electric arc blast nozzle 10, particularly in one of the embodiments shown in Figures 1 to 3.

[0050] In the modifications illustrated in Figures 1 to 4, the number of outer layers does not necessarily have to be equal to two outer layers 32; rather, there may be only one outer layer 32 (reinforcement layer 33). It is also possible to provide three or more outer layers 32. Variations in the number of outer layers 32 can be realized in any embodiment of the electric arc blast nozzle 10, particularly in the embodiments shown in Figures 1 to 4.

[0051] An important aspect of the present invention is the close two-dimensional contact in the outer layer 32 directly adjacent to the outer surface 35 of the inner housing 12, as schematically shown in Figure 6. Similarly, as exemplary shown in Figure 6, when two or more outer layers 32 are present, close two-dimensional contact is generated between two adjacent outer layers 32. In particular, in the connection region of the outer layer 32 in direct contact with the outer surface 35 of the housing, no gas (especially air) filled gaps or cavities 36 are generated, as in the case where adjacent parts are assembled to each other (see the prior art shown in Figure 5).

[0052] To avoid the formation of gas-filled cavities 36, an outer layer 32 directly adjacent to the outer surface 35 of the housing may be connected to the outer surface 35 in a material bonding manner during and as a result of the fabrication of the directly adjacent outer layer 32. The directly adjacent outer layer 32 may be an insulating layer 34 as shown in Figure 6, or a reinforcing layer 33.

[0053] At least one outer layer 32 can be manufactured in a molding process, such as an injection molding process. For example, an outer layer 32 directly adjacent to the housing outer surface 35 can be manufactured by a multi-component molding process and thus molded onto each surface area of ​​the housing outer surface 35 (overmolded outer layer). If there are two or more outer layers 32, at least one additional outer layer 32 can each be manufactured by a molding process and molded on top of a previous outer layer. For example, in Figure 6, first, the innermost outer layer 32 directly adjacent to the housing outer surface 35 is molded on it, and then the next outer layer 32 is molded on top of the innermost outer layer 32. This process can be continued similarly if there are three or more outer layers 32.

[0054] Before overmolding the housing outer surface 35 with the directly adjacent outer layer 32, the housing outer surface 35 may undergo chemical, electrochemical, physical, or thermal surface treatment processes, such as etching. This surface treatment process may be used to modify the chemical composition of the internal housing material in a volume portion including at least the housing outer surface 35. In this volume portion, the existing chemical components can be modified, reduced, or removed. For example, if the internal housing 12 or its covered sections 16 and / or 17 and / or 18 contains fluorine, such as fluorocarbon polymer material such as PTFE, it may be possible to remove fluorine in this volume portion or at least reduce its proportion.

[0055] The thickness of the reinforcing layer 33 can be adapted to the dimensions of the internal housing 12. In one embodiment, the thickness of the reinforcing layer 33 is at least 50% of the wall thickness of the internal housing at the location where the internal housing has its minimum thickness.

[0056] The present invention relates to an electric arc blast nozzle 10 having an internal housing 12 extending along a longitudinal axis X and enclosing an internal space 13. The internal housing 12 is particularly configured to house the electrical contacts 24, 25 of a circuit breaker 11. When used in a circuit breaker, the electric arc blast nozzle 10 can move longitudinally L with respect to one of the electrical contacts and the other. According to the present invention, the internal housing 12 of the electric arc blast nozzle 10 is closely covered by at least one outer layer 32 having a reinforcing layer 33. In doing so, gas-filled gaps and cavities between the at least one outer layer 32 and the internal housing 12 are avoided, which reduces the risk of partial discharge. [Explanation of Symbols]

[0057] 10 Electric arc blast nozzles 11 Circuit breaker 12 Internal Housing 13 Interior space 14 First axial end of the internal housing 15 Second axial end of the internal housing 16 First nozzle end section 17. Second nozzle end section 18. Intermediate nozzle section 19 Inserts 24 First electrical contact 25. Second electrical contact 26 Gas flow generator 27 Pistons 28 Cylinder Chamber 32 Outer layer 33 Reinforcement layer 34 Insulating layer 35 Housing exterior 36 Cavity EA Electric Arc G gas flow L Longitudinal direction X Longitudinal axis

Claims

1. An electric arc blast nozzle (10) configured for use in a high-voltage circuit breaker (11), wherein the electric arc blast nozzle (10) is - An internal housing (12) extending along a longitudinal axis (X) and having a first nozzle end section (16), a second nozzle end section (17), and an intermediate nozzle section (18) positioned between the first nozzle end section (16) and the second nozzle end section (17), viewed from a longitudinal direction (L) parallel to the longitudinal axis (X). - At least one outer layer (32) comprising a reinforcing layer (33) directly or indirectly connected to the outer surface (35) of the inner housing (12) by close two-dimensional contact and An electric arc blast nozzle (10) is provided.

2. The electric arc blast nozzle according to claim 1, wherein the at least one outer layer (32) is attached to the outer surface (35) of the inner housing (12) by material bonding.

3. The electric arc blast nozzle according to claim 1, wherein the at least one outer layer (32) is attached to the outer surface (35) of the inner housing (12) during and as a result of the formation of the at least one outer layer (32).

4. The electric arc blast nozzle according to claim 1, wherein the at least one outer layer (32) is attached to the outer surface (35) of the inner housing (12) by overmolding the inner housing (12).

5. The electric arc blast nozzle according to claim 1, wherein at least two outer layers (32) are provided.

6. The electric arc blast nozzle according to claim 5, wherein at least two outer layers (32) are provided with an insulating layer (34) for increasing dielectric strength.

7. The electric arc blast nozzle according to claim 6, wherein the insulating layer (34) is disposed between the internal housing (12) and the reinforcing layer (33), or the reinforcing layer (33) is disposed between the internal housing (12) and the insulating layer (34).

8. The electric arc blast nozzle according to claim 5, wherein the at least two outer layers (32) are attached to each other by material bonding.

9. The electric arc blast nozzle according to claim 5, wherein the at least two outer layers (32) are attached to each other during the generation of at least one of the at least two outer layers (32) and as a result of the generation of at least one of the at least two outer layers (32).

10. The electric arc blast nozzle according to claim 5, wherein the at least two outer layers (32) are attached to each other by overmolding one of the at least two outer layers (32) with the other one of the at least two outer layers (32).

11. The electric arc blast nozzle according to claim 1, wherein the reinforcing layer (33) extends longitudinally (L) over the first nozzle end section (16) in part or in whole, and the reinforcing layer (33) does not cover at least a portion of the intermediate nozzle section (18) and does not cover the second nozzle end section (17).

12. The electric arc blast nozzle according to claim 11, wherein the reinforcing layer (33) extends longitudinally (L) across the first nozzle end section (16) and partially or entirely across the intermediate nozzle section (18), and the reinforcing layer (33) does not cover the second nozzle end section (17).

13. The electric arc blast nozzle according to claim 12, wherein the reinforcing layer (33) extends longitudinally (L) across the first nozzle end section (16), across the intermediate nozzle section (18), and partially or entirely across the second nozzle end section (17).

14. The electric arc blast nozzle according to claim 13, wherein the reinforcing layer (33) extends in the longitudinal direction (L) over the entire internal housing (12).

15. The electric arc blast nozzle according to any one of claims 1 to 14, wherein the reinforcing layer (33) comprises at least one of synthetic resin, preferably epoxy resin, polymer material, ceramic material, and reinforcing fiber.

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