A target cladding seal structure

Abstract

The utility model discloses a target material cladding seal structure. The seal structure realizes airtightness connection by the cladding cover and the shell through multilayer staggered type inlay mechanism, and the multilayer staggered type inlay mechanism comprises: at least two groups of inlay unit groups distributed along the circumference, and each inlay unit group is composed of a first inlay part on the cladding cover and a second inlay part on the shell, the first inlay part and the second inlay part comprise geometrically complementary convex parts and recessed parts respectively, and the mating interface of the convex part and the recessed part forms an interference fit after assembly, the axial section profile of the convex part and the recessed part is one of the following forms: a straight wall type profile perpendicular to the butt joint direction of the cladding cover and the shell, and a bevel wedge type profile with an acute angle theta with the butt joint direction, theta belongs to (5 DEG, 45 DEG). The application seals the cladding cover and the shell through the multilayer staggered type inlay mechanism, and provides a sealing structure with high sealing property and simple structure.

Description

Technical Field

[0001] This utility model relates to the field of target material cladding and sealing technology, specifically a target material cladding and sealing structure, and more specifically a target material cladding and sealing structure for producing medical isotopes via photonuclear transmutation reaction. Background Technology

[0002] Electron accelerator phototransmutation technology for isotope production offers advantages such as low cost and low impurities. Furthermore, its closed-loop production and management minimize environmental pollution, making it an advanced and environmentally friendly production method. During the irradiation transmutation of the target, radiative heat is deposited on the target and aluminum cladding. A small amount of gas fills the cladding. Water cooling is used to keep the target and cladding below their melting point, while the cladding withstands the pressure of the cooling water flow, ensuring the target and aluminum cladding remain sealed and undamaged during the irradiation transmutation process. Therefore, the pressure resistance and sealing performance of the target's aluminum cladding are crucial aspects of the irradiation transmutation process. Conventional target cladding sealing involves directly welding the cladding cap to the cladding after the target is inserted into the aluminum cladding. However, this welding method has drawbacks: the oxide film hinders bonding. Aluminum oxide films easily form on the aluminum cladding in the air, and during welding, this film impedes effective metal-to-metal bonding, leading to slag inclusions and porosity defects in the weld. Shrinkage and cracking: Aluminum shrinks by up to 5% during solidification, easily causing welding deformation. Under high-temperature arc conditions, the strength and plasticity of aluminum decrease, further leading to poor weld formation or even burn-through. Hydrogen porosity: Hydrogen easily integrates into the molten aluminum pool. Unreleased hydrogen accumulates in the weld, forming pores and reducing sealing reliability. Process complexity and inconsistent quality: As described in Chinese patent CN111128431, while combining circumferential welding and plugging welding can reduce the welding area, it still cannot completely avoid porosity and cracks. Furthermore, the process is complex, and the sealing quality is difficult to stabilize. To avoid welding defects, existing technologies attempt to use a pressure cap sealing scheme. For example, Chinese patent CN104103332A proposes a structure combining a single-crystal aluminum cladding with a pressure cap seal. However, this scheme relies solely on a single radial seal; a small amount of gas generated by the target material during irradiation may cause seal failure, making it difficult to meet long-term reliability requirements. Utility Model Content

[0003] This application provides a target cladding sealing structure to solve the problems of various defects in welds caused by welding seals in existing target cladding seals, and seal failure due to small amounts of gas generated by the target during irradiation caused by gland seals. The specific solution is as follows:

[0004] A target material cladding sealing structure, wherein the sealing structure is achieved by a cladding cover and a housing through a multi-level staggered fitting mechanism to achieve airtight connection; the multi-level staggered fitting mechanism includes: at least two sets of fitting unit groups distributed circumferentially, each set of fitting unit groups consisting of a first fitting part on the cladding cover and a second fitting part on the housing; the first fitting part and the second fitting part respectively include geometrically complementary protrusions and grooves, and the mating interface of the protrusions and grooves forms an interference fit after assembly;

[0005] The axial cross-sectional profile of the protrusion and the groove is one of the following forms:

[0006] (a) A straight-wall profile perpendicular to the direction of mating between the cover and the shell;

[0007] (b) An oblique wedge profile at an acute angle θ to the docking direction, where θ∈(5°,45°).

[0008] Preferably, the fitting points of the cover and the shell are respectively located in the extending directions of the cover and the shell, and the fitting points are staggered in the circumferential direction to ensure multi-point contact and stronger airtightness.

[0009] Preferably, the fitting connection between the cover and the shell is a multi-level fitting, including at least two sets of concave and convex fitting structures, wherein each set of fitting units achieves airtightness and robust connection through interference fit.

[0010] Preferably, the fitting connection between the cover and the shell is a matching concave-convex structure.

[0011] Preferably, the concave and convex structures are respectively adapted wedge-shaped structures.

[0012] Preferably, the fitting points of the cover and the shell are respectively in an F-shaped structure with openings facing each other and staggered.

[0013] Preferably, the fitting connection between the cover and the shell is an interference fit.

[0014] Preferably, the corners at the fitting connection between the cover and the shell are respectively set as matching rounded corners or chamfers to facilitate assembly and positioning and avoid stress concentration.

[0015] Compared with the prior art, the beneficial effects of this application are as follows:

[0016] This application provides a sealing structure with high sealing performance and simple structure by setting the connection between the cover and the shell as an embedded connection, avoiding welding sealing, and using a wedge-type embedded connection to avoid leakage caused by the impact of gas inside the target material shell.

[0017] In this application, by setting the fitting points of the casing cover and the shell along the axial extension directions of the casing cover and the shell respectively, it is suitable for the flow of cooling working fluid from both sides of the maximum contact surface and the pressure caused by the gas generated during the target material transmutation process;

[0018] In this application, the cross-section of the interlocking structure is F-shaped, forming a double "F" fit structure at the connection between the cover and the shell, thereby achieving multiple mechanical interference seals on the contact surfaces of the cover and the shell, further improving its sealing performance; and the double "F" concave-convex structure interlocking joint in this application generates slight thermal deformation, which leads to the sealing effect of multiple contact surfaces being improved when the seal of one contact surface fails.

[0019] This application achieves sealing of the cladding cap and shell through a wedge-shaped interlocking, double "F" structure, and interference fit synergistic effect, providing a simple sealing method that solves the problems of insufficient sealing performance, weak pressure resistance, and poor adaptability to thermal deformation of photonuclear transmutation target cladding materials in the prior art. Attached Figure Description

[0020] Figure 1 This is a cross-sectional schematic diagram of the target material encapsulation and sealing structure in the embodiments of this application;

[0021] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0022] In the diagram: Labels: 1. Shell; 2. Target material; 3. Sheath cover. Detailed Implementation

[0023] A target material cladding and sealing structure includes a cladding cover and a housing that are fitted together. The cladding cover and the housing are connected in an airtight manner by a multi-level staggered fitting mechanism. The multi-level staggered fitting mechanism includes at least two sets of circumferentially distributed fitting unit groups. Each set of fitting unit groups consists of a first fitting part on the cladding cover and a second fitting part on the housing. The first fitting part and the second fitting part respectively include geometrically complementary protrusions and grooves, and the mating interface between the protrusions and the grooves forms an interference fit after assembly.

[0024] The axial cross-sectional profile of the protrusion and the groove is one of the following forms:

[0025] (a) A straight-wall profile perpendicular to the direction of mating between the cover and the shell;

[0026] (b) An oblique wedge profile at an acute angle θ to the docking direction, where θ∈(5°,45°).

[0027] The fitting method is wedge fitting.

[0028] It should be noted that:

[0029] In this application, the wedge-shaped fitting method refers to the fact that the opening edge of the shell 1 is provided with a first connecting groove, and the corresponding position of the shell cover 3 is provided with a second connecting groove, both grooves being adaptable wedge-shaped slope structures (as shown in the attached figure). Figure 2 (As shown in the magnified view at point A). Through axial pressing, the wedge-shaped slopes interlock to form a tight physical seal. By connecting the cladding cover and the shell in a wedge-shaped fit, the cladding cover and the shell form a tight mechanical fit, avoiding weld defects (such as porosity and cracks) caused by oxide film and shrinkage deformation in traditional welding processes, thus significantly improving sealing reliability.

[0030] Furthermore, the fitting points of the cover and the shell are respectively located in the extending directions of the cover and the shell, and the fitting points are staggered in the circumferential direction to ensure multi-point contact and stronger airtightness. The fitting connection between the cover and the shell is a multi-level fitting, including at least two sets of concave-convex fitting structures, wherein each set of fitting units achieves airtightness and firm connection through interference fit.

[0031] It should be noted that:

[0032] The extension direction of the interlocking structure is consistent with the axial force direction of the shell. When the cooling medium (such as water or helium) flows along both sides of the shell axial direction, the interlocking surface is subjected to uniform spray pressure, which further enhances the adhesion stability of the sealing surface and ensures that the sealing surface is consistent with the force direction, thus avoiding loosening of the seal due to external force.

[0033] Furthermore, the fitting connection between the cover and the shell is a double fitting.

[0034] It should be noted that:

[0035] In this application, the double-clamp sealing method enhances the adaptability to thermal expansion and gas pressure during irradiation.

[0036] Furthermore, the fitting connection between the cover and the shell is a matching concave-convex structure.

[0037] It should be noted that in this application, the dual-insertion design and multiple sealing paths work together to form a redundant sealing mechanism. Even if one sealing layer fails, other layers can still provide effective protection, significantly improving the long-term safety during irradiation.

[0038] Furthermore, the concave and convex structures are respectively adapted wedge-shaped structures.

[0039] It should be noted that:

[0040] In this application, the convex-concave structure and wedge design are combined to form multiple physical sealing barriers on the mating surface, effectively preventing internal gas leakage and external cooling medium infiltration.

[0041] Furthermore, the fitting points of the cover and the shell are respectively F-shaped structures with openings facing each other and staggered.

[0042] It should be noted that:

[0043] In this application, the double "F"-shaped staggered interlocking structure forms a leakage path extended through multiple 90° bends. Even if one contact surface fails due to minor deformation caused by thermal stress, the remaining contact surfaces can still maintain a seal.

[0044] Furthermore, the fitting connection between the cover and the shell is an interference fit.

[0045] It should be noted that:

[0046] In this application, the fitting connection between the housing 1 and the cover 3 is an interference fit. Specifically, the dimensions of the "F"-shaped protrusion and the groove are designed to be slightly larger than the matching dimensions. After pressing, the contact surfaces undergo elastic deformation, forming multiple mechanical sealing layers. Even if one contact surface experiences minor failure due to thermal stress during irradiation, the remaining contact surfaces can still maintain a sealing effect.

[0047] Furthermore, the corners at the fitting connection between the cover and the shell are respectively set as matching rounded corners or chamfers.

[0048] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] Example

[0050] As attached Figure 1-2 As shown, a target material encapsulation sealing structure is provided, the sealing structure including a housing 1 and an encapsulation cover 3;

[0051] The shell 1 and the cover 3 form a complete shell. The entire shell includes, but is not limited to, a cuboid or a cylinder. The specific shape is determined according to the shape and size of the target material placed inside.

[0052] In this embodiment, the aluminum cladding of the irradiation transmutation target adopts a double-convex-concave embedded sealing method for the cladding cover and the shell, and the seal is completed by mechanical interference fit of two sets of convex and concave structures. Specifically, the shell 1 and the cladding cover 3 are respectively provided on the side that contacts each other to achieve the fitting. The first connecting groove and the second connecting groove are "F"-shaped structures arranged in a mirror image. That is, the edge of the cladding cover 3 facing the shell 1 is a "F"-shaped protrusion or groove, and the edge of the shell 1 facing the cladding cover 3 is a reverse "F"-shaped groove or protrusion, so as to achieve mutual embedding and thus form a fitted connection structure.

[0053] The protrusions or grooves of the "F" structure are wedge-shaped, meaning that the contact surfaces of the shell 1 and the cover 3 are matching slopes.

[0054] The contact area of ​​the "F" structure of the shell 1 and the cover 3 is an interference fit. The dimensions of the "F" shaped protrusions or grooves of the shell 1 and the cover 3 are interference fit. During assembly, after the target material 2 is inserted into the shell 1, the cover 3 is pressed axially to the opening end of the shell. Mechanical pressure is used to make the "F" shaped wedge structure of the shell 1 and the cover 3 interlock until the interference fit is fully formed. After interlocking, the shell and the cover form five mechanical sealing layers. The internal gas must pass through all corner paths to leak. During the irradiation process, even if the target material generates a small amount of gas or the shell expands due to heat, causing a certain sealing surface to fail, the remaining sealing layers can still maintain the overall sealing performance.

[0055] With the direction of the pressure shell cover 3 as the axial direction, the target material 2 or the generated gas inside needs to pass through five 90° bends formed by the two "F" shaped structures that are interlocked between the shell cover 3 and the shell 1 before it can leak out. The cooling medium (water or helium) separated by the shell also needs to pass through five reverse 90° bends before it can flow into the shell. The shell 1 and the shell cover 3 contact each other to form a limit. The shell is filled with the compacted target material. When the cooling medium mainly flows from the two sides of the axial direction, it will be subjected to the spray pressure of the cooling medium, that is, it will be subjected to force in the interlocking direction. When the transmutation reaction produces a small amount of gas, the external pressure of the cooling working fluid is still much greater than the internal pressure, and the target material and the aluminum cladding are still subjected to force in the mating direction. When the target material and cladding material heat up, if the recessed or raised structure undergoes slight deformation due to thermal stress, causing the interference fit of a certain contact surface to fail, multiple contact surfaces increase the sealing probability. The corners of the raised or recessed structures in the "F" structure are all rounded or chamfered, which facilitates the positioning of the gland assembly and avoids stress concentration at the corners. Therefore, when the shell structure is intact, this new structure provides a more reliable seal compared to ordinary gland seals.

Claims

1. A target material cladding and sealing structure, characterized in that, The sealing structure achieves airtight connection between the cover and the shell through a multi-level staggered fitting mechanism; the multi-level staggered fitting mechanism includes: at least two sets of fitting unit groups distributed circumferentially, each set of fitting unit groups consisting of a first fitting part on the cover and a second fitting part on the shell; the first fitting part and the second fitting part respectively include geometrically complementary protrusions and grooves, and the mating interface of the protrusions and grooves forms an interference fit after assembly; The axial cross-sectional profile of the protrusion and the groove is one of the following forms: (a) A straight-wall profile perpendicular to the direction of mating between the cover and the shell; (b) An oblique wedge profile at an acute angle θ to the docking direction, where θ∈(5°,45°).

2. The target material cladding and sealing structure according to claim 1, characterized in that, The fitting points of the cover and the shell are respectively located in the extending directions of the cover and the shell, and the fitting points are staggered in the circumferential direction to ensure multi-point contact and stronger airtightness.

3. The target material encapsulation and sealing structure according to claim 1, characterized in that, The fitting connection between the cover and the shell is a multi-level fitting, including at least two sets of concave and convex fitting structures, wherein each set of fitting units achieves airtightness and robust connection through interference fit.

4. The target material cladding and sealing structure according to claim 1, characterized in that, The fitting joints between the cover and the shell are respectively fitted with concave and convex structures.

5. The target material cladding and sealing structure according to claim 4, characterized in that, The concave and convex structures are respectively adapted wedge-shaped structures.

6. The target material encapsulation and sealing structure according to claim 1, characterized in that, The fitting points of the cover and the shell are respectively F-shaped structures with openings facing each other and staggered.

7. The target material encapsulation and sealing structure according to claim 1, characterized in that, The fit between the cover and the shell is an interference fit.

8. The target material encapsulation and sealing structure according to claim 1, characterized in that, The corners at the fitting connection between the cover and the shell are respectively set as matching rounded corners or chamfers to facilitate assembly and positioning and avoid stress concentration.

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