Cryogenic vessel p+t plasma welded nozzle

Abstract

The utility model discloses a kind of deep cooling container P+T plasma welding nozzle, including nozzle main body, the nozzle main body inner cavity is equipped with center gas passage being arranged along its axis and auxiliary gas passage being symmetrically arranged in the two sides of center gas passage, the center gas passage includes sequentially arranged introduction section, compression section and spout section along the gas flow direction, the outlet end of spout section constitutes main nozzle hole, the diameter D of main nozzle hole is 4~5mm.By the above-mentioned mode, the utility model can make arc energy distribution more uniform by increasing nozzle aperture, reduce weld defect, improve welding quality and stability;Cancel bevel processing, can simplify pretreatment, realize single-pass welding, improve production efficiency, and realize greater stainless steel plate thickness welding and the good fusion of welded part end surface.

Description

Technical Field

[0001] This utility model relates to the field of cryogenic container welding technology, and in particular to a cryogenic container P+T plasma welding nozzle. Background Technology

[0002] Plasma arc welding, with its high energy density, excellent deep penetration capability, low heat input, low welding deformation, high quality, high efficiency, and good automation compatibility, is increasingly widely used in pressure vessel manufacturing. It is particularly favored in the cryogenic pressure vessel manufacturing industry because it ensures good low-temperature impact toughness in the weld area after welding.

[0003] However, as cryogenic containers develop towards larger and thicker walls, the limitations of traditional plasma arc welding technology have gradually become apparent.

[0004] Currently, the widely used P+T (plasma + filler wire) welding system mainly employs three arc modes: micro-beam plasma, flexible plasma, and keyhole plasma. Among them, keyhole plasma mode, with its strongest penetration capability, has become the preferred choice for thick plate welding, but its maximum weld thickness still does not exceed 10mm. When the plate thickness exceeds this critical value, not only does the weld formation quality decrease significantly, but the non-destructive testing pass rate also drops substantially.

[0005] Furthermore, for plates thicker than 8mm, multiple welding passes are required without beveling the weldment, making it difficult to guarantee the forming quality of the weld back side. This directly affects the overall performance of the joint and the pass rate of flaw detection. Although arc penetration can be enhanced by increasing welding current, increasing ion gas flow rate, decreasing welding speed, or increasing the indentation, achieving a stable and high pass rate for thick plate welding remains a significant challenge.

[0006] As a core component, the nozzle of a plasma welding torch determines the diameter of the welding arc column, playing a crucial role in weld quality and formation. Currently, the diameter of the center hole in commercially available nozzles is ≤Φ4.0mm. This limitation restricts the further strengthening of the plasma arc and the improvement of deep penetration capability, thus affecting the feasibility and stability of thick plate welding. Utility Model Content

[0007] The main technical problem solved by this utility model is to provide a P+T plasma welding nozzle for cryogenic containers. Increasing the nozzle orifice diameter can make the arc energy distribution more uniform, reduce weld defects, and improve welding quality and stability. Eliminating beveling simplifies pretreatment, achieves single-pass penetration, improves production efficiency, and enables welding of thicker plates and good fusion of the end faces of welded parts.

[0008] To solve the above-mentioned technical problems, the present invention provides a technical solution: a cryogenic container P+T plasma welding nozzle, comprising a nozzle body, wherein the inner cavity of the nozzle body is provided with a central gas channel arranged along its axis and auxiliary gas channels symmetrically arranged on both sides of the central gas channel, the central gas channel comprising an inlet section, a compression section and an outlet section arranged sequentially along the gas flow direction, the outlet end of the outlet section forming a main nozzle orifice, and the diameter D of the main nozzle orifice being 4~5mm.

[0009] In a preferred embodiment of this utility model, the inlet section and the outlet section are cylindrical channels, and the compression section is a frustum-shaped channel. The segmented design enables the plasma gas to be gradually compressed during the flow process, thereby increasing the gas flow rate and pressure and enhancing the welding effect.

[0010] In a preferred embodiment of this invention, the angle between the conical surface of the compression section and the central axis is 60-90°, which can ensure the gas compression effect while avoiding excessive resistance during the compression process and ensuring smooth gas flow.

[0011] In a preferred embodiment of this utility model, the angle between the conical surface of the compression section and the central axis is 68°.

[0012] In a preferred embodiment of this utility model, the auxiliary gas channel is a narrow-diameter channel, and its axis is parallel to the axis of the main nozzle hole.

[0013] In a preferred embodiment of the present invention, the outlet end of the auxiliary gas channel and the outlet end of the main nozzle orifice are located on the same plane.

[0014] In a preferred embodiment of the present invention, a cooling chamber is formed above the inner cavity of the nozzle body surrounding the central gas channel, and the ratio of the axial height h of the cooling chamber to the total length L of the central gas channel is 1:1.3 to 1:2.

[0015] In a preferred embodiment of this utility model, the gap b of the plate weld corresponding to the main nozzle hole is 1~3mm.

[0016] In a preferred embodiment of this utility model, the nozzle body is a copper nozzle and the plate is a stainless steel plate.

[0017] In a preferred embodiment of this utility model, the diameter D of the main nozzle hole is 4mm, and the weld gap b of the plate corresponding to the main nozzle hole is 2mm.

[0018] The beneficial effects of this utility model are: increasing the nozzle orifice diameter, resulting in a more uniform energy distribution of the large-diameter electric arc, reducing weld defects caused by concentrated heat input, and improving welding stability and quality; eliminating the beveling process, reducing the pre-treatment process of the base material, and enabling the electric arc to directly penetrate the weldment in a single welding pass, thereby improving production efficiency and pass rate; increasing the stable welding thickness of stainless steel plates to over 10mm, achieving greater plate thickness welding and good fusion of the weldment end faces. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein: Fig. 1 This is a schematic diagram of a preferred embodiment of the P+T plasma welding nozzle for cryogenic containers according to this utility model; Fig. 2 This is a structural schematic diagram of a preferred embodiment of the plate weld joint position corresponding to the P+T plasma welding nozzle for cryogenic containers of this utility model. The components in the attached diagram are labeled as follows: 1. Nozzle body, 2. Central gas passage, 21. Inlet section, 22. Compression section, 23. Ejection section, 3. Cooling chamber, 4. Main nozzle orifice, 5. Auxiliary gas passage. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0022] This utility model relates to a preferred embodiment of a P+T plasma welding nozzle for cryogenic containers.

[0023] Please see Figs. 1-2The cryogenic container P+T plasma welding nozzle includes a nozzle body 1, a central gas channel 2, and an auxiliary gas channel 5.

[0024] The nozzle body 1 is made of copper, which has excellent thermal conductivity and can quickly conduct away the heat generated during welding, preventing the nozzle from being damaged by high temperatures and extending its service life. The inner cavity of the nozzle body 1 is provided with a central gas channel 2 arranged along its axis and auxiliary gas channels 5 symmetrically arranged on both sides of the central gas channel 2. The central gas channel 2 is used to transport plasma gas, and the auxiliary gas channels 5 can further compress the welding arc in the central area, thereby further improving the arc penetration.

[0025] In this invention, the central gas channel 2 includes an inlet section 21, a compression section 22, and an outlet section 23 arranged sequentially along the gas flow direction. The inlet section 21 and the outlet section 23 are cylindrical channels, and the compression section 22 is a frustum-shaped channel. This segmented structure enables the plasma gas to be gradually compressed during the flow process, thereby increasing the gas flow rate and pressure and enhancing the welding effect.

[0026] Furthermore, the angle between the conical surface of the compression section 22 and the central axis is 60-90°, preferably 68°, which can ensure the gas compression effect while avoiding excessive resistance during the compression process and ensuring smooth gas flow.

[0027] Furthermore, the outlet end of the ejection section 23 forms a main nozzle hole 4, the diameter D of the main nozzle hole 4 is 4~5mm, the weld gap b of the plate corresponding to the main nozzle hole 4 is 1~3mm, and the plate is stainless steel.

[0028] This invention increases the nozzle orifice diameter, breaking through the traditional limitation of the nozzle center hole diameter ≤ Φ4.0mm. By optimizing and expanding the orifice diameter, the arc diameter is increased, the energy distribution is more uniform, thereby improving the arc penetration ability and the stability of the molten pool.

[0029] At the same time, the beveling is eliminated. By adjusting the assembly gap of the plates, it is more conducive to the penetration of the welding arc into the weldment, thereby achieving welding of larger plate thicknesses and good fusion of the end faces of the welded specimens, avoiding the extra processes and costs brought about by traditional beveling.

[0030] In one exemplary embodiment, the diameter D of the main nozzle hole 4 is 4 mm, and the weld gap b of the plate corresponding to the main nozzle hole 4 is 2 mm. This size design matches the welding requirements of stainless steel plates, so that the plasma arc can be precisely applied to the welding area and ensure the welding quality.

[0031] Based on the above structure, an auxiliary gas channel 5 is arranged on each side of the central gas channel 2. The auxiliary gas channel is a narrow channel, and its axis is parallel to the axis of the main nozzle hole 4. The outlet end of the auxiliary gas channel 5 and the outlet end of the main nozzle hole 4 are located on the same plane.

[0032] The narrow-diameter auxiliary gas channel can help to further compress the central welding arc and work synergistically with the central airflow to strongly compress the arc, thereby further enhancing the arc penetration.

[0033] In this invention, a cooling chamber 3 is formed around the central gas channel 2 above the inner cavity of the nozzle body 1. This chamber is used to introduce a cooling medium and to ensure that the cooling medium is evenly distributed within the cooling chamber, making full contact with the nozzle body and improving the cooling efficiency of the nozzle body.

[0034] Furthermore, the ratio of the axial height h of the cooling chamber 3 to the total length L of the central gas channel 2 is 1:1.3 to 1:2, which ensures that the cooling chamber 3 has sufficient cooling space while avoiding the excessive size of the nozzle body due to an overly large cooling chamber.

[0035] The beneficial effects of this novel P+T plasma welding nozzle for cryogenic containers are: Increase the nozzle orifice diameter: By enlarging the nozzle orifice diameter, the traditional limitation of the center hole diameter of the nozzle ≤ Φ4.0mm is broken, which increases the arc diameter and makes the energy distribution more uniform, thereby improving the arc penetration ability and the stability of the molten pool, reducing weld defects caused by concentrated heat input, and is suitable for cryogenic containers; Eliminating the beveling: By adjusting the gap between the plates, there is no need to beveling. Single-pass welding allows the arc to penetrate the workpiece directly, avoiding the extra steps and costs associated with traditional beveling and improving the welding qualification rate. The stable welding thickness of stainless steel plates has been increased to over 10mm, ensuring that the molten pool is controllable and the weld formation is good on both sides during thick plate welding, and improving the weld formation quality, thus solving the application bottleneck of traditional plasma welding in the field of thick plates.

[0036] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made using the content of this utility model specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A cryogenic container P+T plasma welding nozzle, characterized in that, Including the nozzle body, The nozzle body has a central gas channel arranged along its axis and auxiliary gas channels symmetrically arranged on both sides of the central gas channel. The central gas channel includes an inlet section, a compression section, and an outlet section arranged sequentially along the gas flow direction. The outlet end of the outlet section forms the main nozzle orifice, and the diameter D of the main nozzle orifice is 4~5mm.

2. The cryogenic container P+T plasma welding nozzle according to claim 1, characterized in that, The inlet section and the outlet section are cylindrical channels, and the compression section is a frustum-shaped channel.

3. The cryogenic container P+T plasma welding nozzle according to claim 2, characterized in that, The angle between the conical surface of the compression section and the central axis is 60-90°.

4. The cryogenic container P+T plasma welding nozzle according to claim 2, characterized in that, The angle between the conical surface of the compression section and the central axis is 68°.

5. The cryogenic container P+T plasma welding nozzle according to claim 1, characterized in that, The auxiliary gas channel is a narrow-diameter channel, and its axis is parallel to the axis of the main nozzle orifice.

6. The cryogenic container P+T plasma welding nozzle according to claim 5, characterized in that, The outlet end of the auxiliary gas channel is located on the same plane as the outlet end of the main nozzle orifice.

7. The cryogenic container P+T plasma welding nozzle according to claim 1, characterized in that, A cooling chamber is formed above the inner cavity of the nozzle body, surrounding the central gas channel. The ratio of the axial height h of the cooling chamber to the total length L of the central gas channel is 1:1.3 to 1:

2.

8. The cryogenic container P+T plasma welding nozzle according to claim 1, characterized in that, The gap b between the weld joints of the plate corresponding to the main nozzle hole is 1~3mm.

9. The cryogenic container P+T plasma welding nozzle according to claim 1, characterized in that, The nozzle body is a copper nozzle, and the plate is a stainless steel plate.

10. The cryogenic container P+T plasma welding nozzle according to claim 8, characterized in that, The diameter D of the main nozzle hole is 4mm, and the weld gap b of the corresponding plate is 2mm.

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