A method of manufacturing a heat preservation tube holder

Abstract

This invention discloses a method for manufacturing an insulated pipe support. The mating surfaces of the semi-tube shell are machined into a stepped shape, comprising a first mating section and a second mating section. The first mating section is machined as a slope with a cutting depth gradually increasing from the side near the outer wall to the side near the inner wall, and a blind hole is correspondingly machined. An insert with a coefficient of linear expansion greater than that of the insulation material is inserted into the blind hole for mating. At room temperature, the insert and the blind hole have a clearance fit to reduce construction resistance, and a gap gradually narrows from the inside to the outside is formed between the first mating sections. Under high-temperature conditions, the radial thermal expansion of the insert is converted into an interference fit with the hole wall, and the resulting lateral extrusion force effectively restricts the relative misalignment of the semi-tube shell. Driven by this force, the insulation material around the hole wall is forced to undergo local extrusion deformation, protruding into the gap to actively absorb high-temperature thermal stress, mitigate the risk of cracking, and force the gap to close, establishing a tight thermal barrier.

Description

Technical Field

[0001] This invention relates to the field of pipeline insulation technology, and more specifically, to a method for manufacturing an insulated pipe support. Background Technology

[0002] In industries such as petrochemicals, power generation, and metallurgy, insulated pipe supports are widely used to support and wrap pipelines transporting high-temperature media, thereby reducing heat loss in the pipeline network. Traditional insulated pipe supports are typically made of rigid insulation material molded into two half-pipe shells, which are then joined together on-site using external metal clamps or adhesives to cover the outside of the pipeline.

[0003] Under actual high-temperature conditions, due to the extremely high surface temperature of the pipe, the inner side of the pipe support close to the pipe experiences severe thermal expansion, while the outer side of the pipe support, in contact with the natural environment, has a lower temperature and smaller expansion. This huge temperature difference between the inside and outside generates intense thermal stress concentration within the insulation material of the pipe support. Traditional pipe supports mostly use straight butt joints or simple rigid stepped butt joints, which lack effective stress release and clearance space when subjected to intense radial and circumferential thermal expansion. Long-term alternating thermal loads not only easily lead to brittle cracking of the pipe shell due to stress concentration, but also force the joint surfaces of the two half-pipe shells to open up and become relatively misaligned, thus triggering a thermal bridging effect, resulting in a significant reduction in insulation performance, and even endangering the overall safety of the piping system structure. Summary of the Invention

[0004] In view of the problems in the prior art where the rigid connection of the two half-pipe shells under high-temperature conditions lacks thermal expansion avoidance space, resulting in the concentration of high-temperature thermal stress inside, which leads to cracking of the half-pipe shells, widening of the gap at the connection, and relative misalignment, the present invention provides a method for manufacturing an insulated pipe support.

[0005] The method for manufacturing the thermal insulation pipe support provided by the present invention includes the following steps: S1. Form two half-shells made of machinable insulation material, each half-shell having an inner wall surface, an outer wall surface, and two mating surfaces connecting the two. S2. Each mating surface is processed into a stepped shape in cross-section, and each mating surface includes a first mating segment and a second mating segment in sequence along the direction from the inner wall surface to the outer wall surface. S3. Each first mating section is machined into a bevel, and the cutting depth of the first mating section gradually increases from the side closer to the outer wall surface to the side closer to the inner wall surface. S4. On each pair of first mating sections where the two half-shells are positioned opposite each other, blind holes with corresponding positions are machined. S5. Select multiple inserts with a linear expansion coefficient greater than that of the insulation material; insert one end of each insert into the blind hole corresponding to one of the half-shells, then join the two half-shells together so that the other end of each insert is inserted into the blind hole corresponding to the other half-shell, thus forming an insulation pipe support; at this time, there is a clearance fit between each insert and the hole wall of its respective blind hole; the second mating sections of the two half-shells with opposite positions fit together, and the first mating sections of the two half-shells with opposite positions fit together at the edge near the outer wall surface, thereby forming a support between the two half-shells with opposite positions. Between the first mating sections, a gap is formed that gradually narrows from the side closer to the inner wall to the side closer to the outer wall. The insulation pipe support is configured such that when it is in a high-temperature operating condition, the radial thermal expansion of each insert is converted into an interference fit with the hole wall of its respective blind hole, generating a compressive force to limit the relative misalignment of the two half-shells. Under the drive of this compressive force, the insulation material around the hole wall of each blind hole is forced to undergo local compressive deformation. The locally compressive deformed material protrudes into the gap to absorb thermal stress, thereby forcing the gap to tend to close.

[0006] Preferably, on each pair of first mating sections where the two half-shells are positioned opposite each other, a plurality of blind holes are distributed at intervals along the length of the half-shell; and an insert is inserted into each blind hole corresponding to each other.

[0007] Preferably, the length of each insert is less than the sum of the depths of the two blind holes in which it is located, so as to leave an expansion gap along the length direction of the insert at the bottom of the blind hole.

[0008] Preferably, on each mating surface, the angle between the plane containing the first mating segment and the plane containing the second mating segment is 3° to 15°.

[0009] Preferably, the linear expansion coefficient of the insert is at least 1.5 times that of the thermal insulation material.

[0010] Preferably, the insulation material is rigid polyurethane foam, polyisocyanurate foam, or high-density calcium silicate. The insert is a resin part or a metal part formed of a high-temperature resistant polymer material.

[0011] Preferably, the cross-sectional shapes of the blind hole and the insert are compatible and are both non-circular polygons; when in the clearance fit and interference fit states, the outer wall of each insert abuts against the wall of the blind hole in which it is located, so as to restrict the insert from rotating within the blind hole.

[0012] Preferably, in S5, before joining the two half-shells, a heat-resistant sealant is applied to the surface of the second joining section of each half-shell; after the two half-shells are joined, the opposing second joining sections are bonded together by the heat-resistant sealant.

[0013] Preferably, each of the inserts has a guide chamfer at both ends of its edge to guide the insert into the corresponding blind hole smoothly in the clearance fit state.

[0014] The manufacturing method of the thermal insulation pipe support provided by this invention has achieved the following significant technical effects: During the room temperature assembly stage, each insert has a clearance fit with its respective blind hole, reducing the construction resistance of the two half-shells. When the insulation pipe support is under high temperature conditions, the radial thermal expansion of each insert is converted into an interference fit with the wall of its respective blind hole. This lateral extrusion force, directly converted by heat, constructs a rigid constraint inside the two half-shells that increases with temperature, effectively limiting the relative misalignment of the two half-shells.

[0015] Furthermore, by machining the first mating section into a bevel with gradually increasing cutting depth, a gap is formed between the opposing first mating sections, gradually narrowing from the side closer to the inner wall to the side closer to the outer wall. Driven by this lateral extrusion force, the insulating material around the walls of each blind hole is forced to undergo local extrusion deformation. The reserved gap provides a precise release outlet for this deformed material. The locally extruded material protrudes and releases into the gap, not only actively absorbing high-temperature thermal stress and mitigating the risk of brittle fracture of the shell, but also forcing the gap to tend to close. Thus, without adding complex external sealing devices, a thermal barrier that becomes increasingly tight as the temperature rises is established. Attached Figure Description

[0016] Figure 1 These are the front sectional views of the two half-shells after processing in steps S1 to S3 in this embodiment of the invention; Figure 2 This is a front sectional view of the two half-shells after the blind hole is machined in step S4 of this embodiment of the invention. Figure 3 This is a front sectional view of the insulation pipe support after assembly in step S5 of the present invention under normal temperature conditions. Figure 4 for Figure 3 A magnified view of a section at point A in the middle; Figure 5 This is a cross-sectional view of the insulation pipe support under the high-temperature condition described in step S5 in an embodiment of the present invention.

[0017] Explanation of reference numerals in the attached drawings: 10, half-shell; 11, inner wall surface; 12, outer wall surface; 13, mating surface; 131, first mating section; 132, second mating section; 133, connecting section; 14, blind hole; 20, insert; 21, guide chamfer; 30, gap. Detailed Implementation

[0018] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0019] Reference Figures 1 to 5 As shown, this invention provides a method for manufacturing an insulated pipe support. This method, through the deep coupling of specific geometric cutting processes and the thermal deformation characteristics of materials, produces an insulated pipe support capable of adaptive absorption of internal thermal stress, preventing misalignment, and possessing both internal and external thermal barrier properties under high-temperature conditions. The manufacturing method specifically includes the following steps.

[0020] In step S1, two semi-shells 10 made of machinable insulation material are formed. In practical engineering applications, the insulation material is selected based on the temperature rating of the medium in the pipeline to be insulated. For example, when the temperature of the transported medium is below 150°C, rigid polyurethane foam or polyisocyanurate foam can be selected; when the transported medium is superheated steam above 300°C, high-density calcium silicate material with higher pressure resistance is preferred. Each semi-shell 10 after forming has an inner wall surface 11, an outer wall surface 12, and two mating surfaces 13 connecting the two, wherein the curvature of the inner wall surface 11 is adapted to the curvature of the outer wall of the high-temperature pipeline to be insulated.

[0021] In steps S2 and S3, refer to Figure 1As shown, the mating surfaces 13 of each half-shell 10 are CNC machined. To improve production speed, in actual manufacturing, a forming milling cutter is usually used to directly machine the mating surfaces 13 into a stepped shape and simultaneously cut out bevels in a single pass. The machined mating surfaces 13, along the direction from the inner wall surface 11 to the outer wall surface 12, sequentially include a first mating section 131, a connecting section 133, and a second mating section 132. In terms of spatial geometry, the area where the first mating section 131 is located and the plane where the second mating section 132 is located are offset from each other in the snapping direction of the half-shell 10, arranged with a height difference; the connecting section 133, as a transition folded surface with a height difference, connects its two ends to the inner first mating section 131 and the outer second mating section 132, respectively. This three-segment profile with offset and alternating surfaces constitutes a substantial stepped structure in cross-section. This stepped structure not only physically creates a tortuous interface, significantly extending the labyrinthine conduction path of heat radiation from the inside out, but also weakens the thermal bridging effect at the joints from the structural source.

[0022] Furthermore, the first mating segment 131 located on the inner side is machined into a bevel with a cutting angle, such that the cutting depth of the bevel gradually increases from the side near the outer wall surface 12 to the side near the inner wall surface 11. In a preferred embodiment, the included angle between the planes containing the first mating segment 131 and the second mating segment 132 on each mating surface 13 is set to 3° to 15°. For example, in Figure 1 and Figure 2 In the illustrated embodiment, the included angle is machined to 5°. In an alternative embodiment, for ultra-high temperature pipes with severe thermal expansion, the included angle can be increased to 10° or 15° to provide greater clearance. If the included angle is less than 3°, sufficient volume space cannot be formed to absorb the forced deformation of the material. If it is greater than 15°, the solid wall thickness of the half-shell 10 on the inner side will be excessively weakened, reducing the load-bearing strength of the pipe support on the pipe.

[0023] In step S4, refer to Figure 2 As shown, blind holes 14 are machined on each pair of first mating sections 131 opposite to the two semi-shell shells 10. To ensure uniform axial force on the semi-shell shells 10, multiple blind holes 14 are spaced apart along the length of the semi-shell shells 10. As a better failure prevention design, the cross-sectional shape of the blind holes 14 is machined into a non-circular polygon, such as a square, rectangle, or regular hexagon, to cooperate with the insert to prevent rotational failure.

[0024] In step S5, the insulation pipe support is assembled on-site, directly covering the exterior of the high-temperature pipe to be insulated. First, multiple inserts 20 with a linear expansion coefficient greater than that of the insulation material are selected. The inserts 20 can be made of high-temperature resistant resin or stainless steel. Taking a high-density calcium silicate half-shell with stainless steel inserts as an example, the linear expansion coefficient of stainless steel is typically 1.5 to 3 times greater than that of calcium silicate, thus ensuring a smooth transition of the subsequent thermodynamic state. Before assembly, guide chamfers 21 are pre-processed at both ends of each insert 20, and a high-temperature resistant sealant is applied to the surface of the second mating section 132 of each half-shell 10. Then, one end of each insert 20 is inserted into the blind hole 14 of one of the half-shells 10 under the guidance of the guide chamfers 21. Next, the two half-shells 10 are respectively fastened together from both sides of the high-temperature pipe. After the mating is completed, the inner wall surfaces 11 of the two half-shells 10 are joined together to form a complete pipe cavity, tightly fitting and covering the outer wall surface of the high-temperature pipe.

[0025] Reference Figure 3 and Figure 4 As shown, after assembly at room temperature, the clearance fit between the outer wall of the insert 20 and the wall of the blind hole 14 significantly reduces the resistance of on-site assembly. In this state, the two opposing second mating sections 132 of the two half-tube shells 10 are tightly bonded together by heat-resistant sealant. This bonding surface not only forms the structural reference of the outer periphery of the pipe support, but also establishes an absolute static physical isolation layer on the outermost edge of the pipe support. This isolation layer effectively blocks the path of cold air and water vapor in the external natural environment to penetrate into the interior of the pipe support through the joint, avoiding condensation or thermal shock cracking of the insulation material caused by the intrusion of external cold and the encounter of internal high temperature. At the same time, the opposing first mating sections 131 are bonded together only at the edge near the outer wall surface 12. Based on the inclined design of the first mating section 131, a gap 30 that gradually narrows from the side near the inner wall surface 11 to the side near the outer wall surface 12 is naturally formed between the two opposing first mating sections 131. Furthermore, to prevent the inserts 20 from excessively elongating axially after heating and thus opening the semi-tube shell 10, the length of each insert 20 is less than the sum of the depths of the two blind holes 14 it contains. For example, if the total depth of the blind hole 14 is 40 mm and the length of the insert 20 is 35 mm, a 5 mm expansion gap is reserved at the bottom of the blind hole 14.

[0026] Reference Figure 5As shown, this invention demonstrates the thermodynamic adaptive closure and stress absorption process of the insulation pipe support after being wrapped around a pipeline under actual high-temperature conditions. This process fully reflects the substantial innovative contribution of this solution in addressing the pain point of high and low temperature differences. When the high-temperature medium passes through the pipeline, heat is directly transferred from the outer wall surface of the high-temperature pipeline to the inner wall surface 11 in close contact with it. Since the linear expansion coefficient of the insert 20 is significantly greater than that of the insulation material, the radial thermal expansion of each insert 20 is much greater than the expansion of the wall material of the blind hole 14. This causes the clearance fit between each insert 20 and the wall of its respective blind hole 14 to quickly transform from a clearance fit at room temperature to an interference fit at high temperature.

[0027] On the one hand, when in this interference fit state, the outer wall of the polygonal insert 20 is tightly abutted against the wall of the blind hole 14, restricting the insert 20 from rotating. More importantly, the interference fit due to expansion transformation creates a strong lateral compressive force inside the half-shell 10. This compressive force makes the insert 20 act like a solid rigid pin implanted inside the half-shell 10, relying on its own shear strength to absolutely restrict the relative misalignment of the two half-shells 10 in the lateral or longitudinal direction due to uneven thermal expansion and contraction.

[0028] On the other hand, under the continuous drive of this lateral extrusion force, the softer insulating material around the walls of each blind hole 14 is forced to undergo local extrusion deformation. At this time, the pre-cut gap 30 becomes a precise pressure relief channel for these deformed materials. The locally extruded material bulges out into the gap 30 under physical force, which not only completely resolves the concentrated thermal stress that would have caused brittle cracking of the tube shell, but also completely fills and compacts the wedge-shaped gap 30, forcing the gap 30 to tend to close completely.

[0029] Based on the above dynamic evolution process, this invention forms a double-sealed defense system under high-temperature conditions. The second connecting section 132 on the outer side blocks the intrusion of external cold energy with a heat-resistant sealant, while the first connecting section 131 on the inner side uses a high-temperature thermal stress-driven material to fill the gap 30, forming an internal heat-insulating barrier that becomes increasingly dense as the temperature rises, completely preventing the leakage of internal high temperature to the outside. This design, which transforms harmful thermal expansion into beneficial sealing dynamics, endows the insulation pipe support with extremely high environmental adaptability and structural service life.

Claims

1. A method for manufacturing an insulated pipe support, characterized in that, Includes the following steps: S1. Form two half-shells made of machinable insulation material, each half-shell having an inner wall surface, an outer wall surface, and two mating surfaces connecting the two. S2. Each mating surface is processed into a stepped shape in cross-section, and each mating surface includes a first mating segment and a second mating segment in sequence along the direction from the inner wall surface to the outer wall surface. S3. Each first mating section is machined into a bevel, and the cutting depth of the first mating section gradually increases from the side closer to the outer wall surface to the side closer to the inner wall surface. S4. On each pair of first mating sections where the two half-shells are positioned opposite each other, blind holes with corresponding positions are machined. S5. Select multiple inserts with a linear expansion coefficient greater than that of the insulation material; insert one end of each insert into the blind hole corresponding to one of the half-shells, then join the two half-shells together so that the other end of each insert is inserted into the blind hole corresponding to the other half-shell, thus forming an insulation pipe support; at this time, there is a clearance fit between each insert and the hole wall of its respective blind hole; the second mating sections of the two half-shells with opposite positions fit together, and the first mating sections of the two half-shells with opposite positions fit together at the edge near the outer wall surface, thereby forming a support between the two half-shells with opposite positions. Between the first mating sections, a gap is formed that gradually narrows from the side closer to the inner wall to the side closer to the outer wall. The insulation pipe support is configured such that when it is in a high-temperature operating condition, the radial thermal expansion of each insert is converted into an interference fit with the hole wall of its respective blind hole, generating a compressive force to limit the relative misalignment of the two half-shells. Under the drive of this compressive force, the insulation material around the hole wall of each blind hole is forced to undergo local compressive deformation. The locally compressive deformed material protrudes into the gap to absorb thermal stress, thereby forcing the gap to tend to close.

2. The manufacturing method according to claim 1, characterized in that, On each pair of first mating sections where the two half-shells are positioned opposite each other, there are multiple blind holes spaced apart along the length of the half-shell; and each blind hole corresponding to each other is fitted with an insert.

3. The manufacturing method according to claim 1, characterized in that, The length of each insert is less than the sum of the depths of the two blind holes in which it is located, so as to leave an expansion gap along the length direction of the insert at the bottom of the blind hole.

4. The manufacturing method according to claim 1, characterized in that, On each mating surface, the angle between the plane containing the first mating segment and the plane containing the second mating segment is 3° to 15°.

5. The manufacturing method according to claim 1, characterized in that, The linear expansion coefficient of the insert is at least 1.5 times that of the thermal insulation material.

6. The manufacturing method according to claim 5, characterized in that, The insulation material is rigid polyurethane foam, polyisocyanurate foam, or high-density calcium silicate. The insert is a resin part or a metal part formed of a high-temperature resistant polymer material.

7. The manufacturing method according to claim 1, characterized in that, The cross-sectional shapes of the blind holes and the inserts are adapted to each other, and both are non-circular polygons; when in the clearance fit and the interference fit state, the outer wall of each insert abuts against the hole wall of its respective blind hole to restrict the insert from rotating within the blind hole.

8. The manufacturing method according to claim 1, characterized in that, In S5, before the two half-shells are joined together, a heat-resistant sealant is applied to the surface of the second joint section of each half-shell; after the two half-shells are joined together, the second joint sections that are in opposite positions are bonded together by the heat-resistant sealant.

9. The manufacturing method according to claim 1, characterized in that, Each of the inserts has a guide chamfer at both ends to guide each insert into the corresponding blind hole smoothly in the clearance fit state.

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