Steel-in-steel thermal insulation pipe and production process thereof

Abstract

This invention relates to the technical field of thermal insulation pipes, and in particular to a steel-jacketed thermal insulation pipe and its manufacturing process. It allows for the compression and adjustment of the insulation layer, facilitating the assembly of the inner pipe into the outer pipe, simplifying the concentricity adjustment of the inner and outer pipes, and improving the production efficiency and quality of the steel-jacketed thermal insulation pipe. The pipe includes an inner pipe, an outer pipe, multiple rows of internal support adjustment components, and multiple sets of driving pressure rods. An insulation layer is filled between the inner and outer pipes. Multiple rows of internal support adjustment components are evenly distributed between the inner and outer pipes. Each internal support adjustment component includes multiple sets of internal support adjustment mechanisms, which are circumferentially distributed on the outer wall of the inner pipe. Each internal support adjustment mechanism includes a U-shaped seat, a lifting seat, a first bevel gear, a second bevel gear, and a screw. The U-shaped seat is fixedly installed on the outer wall of the inner pipe. The lifting seat is slidably mounted on the U-shaped seat along the outer wall of the inner pipe. Both the first and second bevel gears are rotatably mounted on the lifting seat. The screw is fixedly connected to the first bevel gear and screwed onto the U-shaped seat.

Description

Technical Field

[0001] This invention relates to the technical field of thermal insulation pipes, and in particular to a steel-jacketed thermal insulation pipe and its manufacturing process. Background Technology

[0002] As is well known, steel-jacketed insulated pipes generally consist of an inner pipe, an outer pipe, and an inner support frame. The outer wall of the inner pipe and the inner wall of the outer pipe are fixedly connected by the inner support frame. An insulation layer is filled between the inner and outer pipes. During the production of steel-jacketed insulated pipes, the outer wall of the inner pipe is covered with an insulation layer, and the inner support frame is welded to the outer wall of the inner pipe. The inner pipe is then inserted into the outer pipe from one end, and the inner support frame near the end of the outer pipe is welded to the inner wall of the outer pipe. However, during production, it was found that the insertion of the inner pipe into the outer pipe is time-consuming and labor-intensive due to the expansion characteristics of the insulation layer. The insulation layer is prone to displacement and tearing during the feeding process, affecting the production efficiency and quality of the steel-jacketed insulated pipes. Furthermore, the concentricity of the inner and outer pipes is difficult to guarantee, the welding workload is large, and there are certain limitations in its use. Summary of the Invention

[0003] (a) Technical problems to be solved

[0004] To address the shortcomings of existing technologies, this invention provides a steel-jacketed insulated pipe and its production process that allows for compression and adjustment of the insulation layer, facilitating the assembly of the inner tube into the outer tube, simplifying the concentricity adjustment of the inner and outer tubes, and improving the production efficiency and quality of steel-jacketed insulated pipes.

[0005] (II) Technical Solution

[0006] To achieve the above objectives, the present invention provides the following technical solution: It includes an inner tube, an outer tube, multiple rows of internal support adjustment components, and multiple sets of driving pressure rods. An insulation layer is filled between the inner and outer tubes. Multiple rows of internal support adjustment components are equidistantly distributed between the inner and outer tubes. Each internal support adjustment component includes multiple sets of internal support adjustment mechanisms, which are circumferentially distributed on the outer wall of the inner tube. Each internal support adjustment mechanism includes a U-shaped seat, a lifting seat, a first bevel gear, a second bevel gear, and a screw. The U-shaped seat is fixedly installed on the outer wall of the inner tube, and the lifting seat extends along the inner tube... The outer wall is slidably mounted on a U-shaped seat. The first and second bevel gears are rotatably mounted on the lifting seat. The screw is fixedly connected to the first bevel gear and screwed onto the U-shaped seat. The driving pressure rod is connected to the collinear second bevel gears on multiple sets of inner support adjustment components. The first and second bevel gears mesh. Furthermore, the insulation layer includes an aluminum foil layer covering the outer wall of the inner tube, a glass wool layer, and an aluminum foil reflective cloth layer adhered to the inner wall of the outer tube. There is a 5-8cm gap between the glass wool layer and the aluminum foil reflective cloth layer.

[0007] Preferably, symmetrically arranged support rods are fixedly installed on the U-shaped seat, and a ball bearing is rotatably installed at the end of the support rod away from the center of the inner tube.

[0008] Preferably, the top of the lifting seat is provided with an arc-shaped plate, and the arc-shaped plate is provided with anti-slip texture; furthermore, the arc-shaped plate fits into the inner wall of the outer tube.

[0009] Preferably, a nut is provided at the end of the drive rod.

[0010] Preferably, the second bevel gear is provided with a cross slot, and the drive rod is provided with a cross protrusion that matches the cross slot, the cross protrusion being inserted into the cross slot.

[0011] Preferably, the lifting seat is provided with a mounting cavity, and the first bevel gear and the second bevel gear are rotatably mounted in the mounting cavity.

[0012] Preferably, the multiple rows of the inner support adjustment components are at least three rows, of which two rows of inner support adjustment components are located near the inner tube port, and one row of inner support adjustment components is located in the middle of the inner tube.

[0013] A manufacturing process for steel-cased insulated pipes includes the following steps:

[0014] S1. Material selection: The inner and outer tubes are made of Q235B material. The outer surface is rust-free to remove steel scale, grease, dust, paint, water and other contaminants.

[0015] S2. Aluminum foil is wrapped around the outer wall of the inner tube: The reserved areas at both ends of the inner tube are not wrapped with aluminum foil. Two layers of aluminum foil are wrapped directly at the beginning and end ends, with a 30-40mm edge pressing and the seam is fixed with tape.

[0016] S3: Install the internal support adjustment mechanism: Prefabricate the internal support adjustment mechanism. First, mark the positioning lines on the outer wall of the inner tube. Wrap a layer of high-temperature resistant nanomaterial around the marked positioning line on the inner tube, and then wrap a layer of asbestos insulation felt around it. The two layers overlap to form an insulation pad. Arrange multiple sets of internal support adjustment mechanisms in a ring shape at the marked positions in the middle of the outer wall of the inner tube and near the inner tube end. Adjust the internal support adjustment mechanisms so that the corresponding internal support adjustment mechanisms arranged along the inner tube axis are collinear, and the deviation of the internal support adjustment mechanisms on the same straight line is less than 0.3mm. Weld or bolt the straightened internal support adjustment mechanism to the outer wall of the inner tube.

[0017] S4. Glass wool layer filling: The glass wool should be wrapped in a straight line, and each layer of glass wool should be tied with No. 18 iron wire at a spacing of 600mm; the last layer of glass wool away from the center of the inner tube should be covered with plastic film.

[0018] S5. Treatment of the inner wall of the outer tube: Aluminum foil reflective cloth is bonded to the inner wall of the outer tube, with the aluminum foil reflective cloth pressing the edge by 30-40mm and fixing it with tape.

[0019] S6. Insulation layer diameter reduction treatment: Pass the drive pressure rod through the inner support adjustment mechanism on the same straight line, and gradually rotate and adjust the drive pressure rod. The pressure rod presses the insulation layer closer to the center of the inner tube until the outer diameter of the insulation layer is 50-60mm smaller than the inner diameter of the outer tube.

[0020] S7. Inner and outer tube assembly: Using hoisting equipment or a forklift, insert one end of the inner tube into the port of the outer tube. Adjust the distance between the two ends of the inner and outer tubes so that the two ends of the outer tube are equidistant from the two ends of the inner tube. Adjust the inner support adjustment mechanism until the central axes of the inner and outer tubes are collinear and the deviation between the central axes of the inner and outer tubes is ≤5mm.

[0021] S8. Corrosion protection treatment of the outer wall of the outer pipe: Apply epoxy coal tar anti-corrosion coating according to the specific anti-corrosion design requirements. The thickness of the epoxy coal tar anti-corrosion layer shall be greater than or equal to 300μm.

[0022] (III) Beneficial Effects

[0023] Compared with the prior art, the present invention provides a steel-jacketed insulated pipe and its manufacturing process, which has the following beneficial effects: The steel-jacketed insulated pipe and its manufacturing process, through the rotation adjustment of the driving pressure rod, and after transmission via the first and second bevel gears, the screw rotates, and the lifting seat feeds radially towards the center of the inner pipe. Meanwhile, the driving pressure rod presses the insulation layer, making the outer diameter of the insulation layer smaller than the inner diameter of the outer pipe. During the assembly of the inner and outer pipes, because the outer diameter of the insulation layer is smaller than the inner diameter of the outer pipe, it effectively prevents the insulation layer from shifting or tearing due to the inner pipe during installation into the outer pipe, thus improving the feeding speed of the inner pipe into the outer pipe. The smoothness of the process is ensured by rotating the drive pressure rod after the inner tube is installed in place. The lifting seat moves radially away from the center of the inner tube by rotating the drive pressure rod. The lifting seat makes close contact with the inner wall of the outer tube, realizing a fixed connection between the inner and outer tubes. At the same time, the drive pressure rod can keep the insulation layer in a compressed state at all times, preventing the insulation layer from falling off. The drive pressure rod can also increase the axial strength of the steel-jacketed steel insulation pipe and can compress and adjust the insulation layer, which is conducive to the assembly of the inner tube into the outer tube. By rotating and adjusting the inner support adjustment mechanism at different positions, the concentricity of the inner and outer tubes can be adjusted, improving the production efficiency and quality of the steel-jacketed steel insulation pipe. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the three-dimensional structure of the outer tube of the present invention, partially cut out;

[0025] Figure 2 This is a top view of the structure of the present invention;

[0026] Figure 3 This is the invention Figure 2 Schematic diagram of the cross-sectional structure at point AA;

[0027] Figure 4 This is the invention Figure 2Schematic diagram of the cross-sectional structure at point BB;

[0028] Figure 5 This is a schematic diagram of the cross-sectional structure of the insulation layer of the present invention;

[0029] Figure 6 This is the invention Figure 1 A magnified view of the structure at point A in the middle;

[0030] The following are labels in the attached diagram: 1. Inner tube; 2. Outer tube; 3. Drive rod; 4. Insulation layer; 5. U-shaped seat; 6. Lifting seat; 7. First bevel gear; 8. Second bevel gear; 9. Screw; 10. Support rod; 11. Ball bearing; 12. Arc plate; 13. Anti-slip texture; 14. Nut; 15. Cross slot; 16. Cross protrusion; 17. Mounting cavity; 18. Aluminum foil layer; 19. Glass wool layer; 20. Aluminum foil reflective cloth layer; 21. Air layer. Detailed Implementation

[0031] The technical solutions of the embodiments 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.

[0032] Please see Figure 1-6 The present invention discloses a steel-clad steel insulation pipe, comprising an inner pipe 1, an outer pipe 2, multiple rows of internal support adjustment components, and multiple sets of driving pressure rods 3. An insulation layer 4 is filled between the inner pipe 1 and the outer pipe 2. The multiple rows of internal support adjustment components are equidistantly distributed between the inner pipe 1 and the outer pipe 2. Each internal support adjustment component includes multiple sets of internal support adjustment mechanisms, which are circumferentially distributed on the outer wall of the inner pipe 1. Each internal support adjustment mechanism includes a U-shaped seat 5, a lifting seat 6, a first bevel gear 7, a second bevel gear 8, and a screw 9. The U-shaped seat 5 is fixedly installed on the outer wall of the inner pipe 1. The lifting seat 6 is slidably mounted on the U-shaped seat 5 along the outer wall of the inner pipe 1. Both the first bevel gear 7 and the second bevel gear 8 are rotatably mounted. On the lifting seat 6, the screw 9 is fixedly connected to the first bevel gear 7. The screw 9 is screwed onto the U-shaped seat 5. The driving pressure rod 3 is connected to the collinear second bevel gear 8 on multiple sets of inner support adjustment components. The first bevel gear 7 and the second bevel gear 8 mesh. Furthermore, the insulation layer 4 includes an aluminum foil layer 18 covering the outer wall of the inner tube 1, a glass wool layer 19, and an aluminum foil reflective cloth layer 20 adhering to the inner wall of the outer tube 2. There is an air layer 21 of 5-8 cm between the glass wool layer 19 and the aluminum foil reflective cloth layer 20. After the glass wool layer 19 is bound by the driving pressure rod 3, the air layer 21 formed can play a certain heat insulation effect, further improving the heat insulation performance of the steel-clad steel insulation pipe.

[0033] Specifically, symmetrically arranged support rods 10 are fixedly installed on the U-shaped seat 5. A ball bearing 11 is rotatably installed at the end of the support rod 10 away from the center of the inner tube 1. When the inner tube 1 is installed into the outer tube 2, the lifting seat 6 is lowered to a position below the end of the support rod 10 away from the center of the inner tube 1. During the feeding process of the inner tube 1 into the outer tube 2, the ball bearing 11 achieves rotational contact between the support rod 10 and the inner wall of the outer tube 2, which can effectively reduce the resistance of the inner tube 1 being fed into the outer tube 2. At the same time, it can avoid damage to the aluminum foil reflective cloth layer 20 on the inner wall of the outer tube 2, and further improve the assembly efficiency of the inner tube 1 and the outer tube 2.

[0034] Specifically, the top of the lifting seat 6 is provided with an arc-shaped plate 12, and the arc-shaped plate 12 is provided with anti-slip texture 13; furthermore, the arc-shaped plate 12 fits into the inner wall of the outer tube 2; through the provision of the arc-shaped plate 12 and the anti-slip texture 13, the friction between the lifting seat 6 and the inner wall of the outer tube 2 can be increased, and the connection strength between the inner tube 1 and the outer tube 2 can be improved.

[0035] Specifically, a nut 14 is provided at the end of the drive lever 3; the nut 14 can provide a point of force for external tools so that external tools can apply force to adjust the drive lever 3.

[0036] Specifically, the second bevel gear 8 is provided with a cross slot 15, and the drive rod 3 is provided with a cross protrusion 16 that fits into the cross slot 15. The cross protrusion 16 is inserted into the cross slot 15. The drive rod 3 is connected to the second bevel gear 8 by a socket, and the drive rod 3 can be pulled out from the cross slot 15 on the second bevel gear 8. After the glass wool layer 19 is freed from its restraint, it comes into close contact with the inner wall of the outer tube 2, and the drive rod 3 can be reused. The steel-clad steel insulation pipe forms an airless layer 21 structure.

[0037] Specifically, the lifting seat 6 is provided with an installation cavity 17, in which the first bevel gear 7 and the second bevel gear 8 are rotatably installed; the first bevel gear 7 and the second bevel gear 8 are installed in the sealed environment of the installation cavity 17 to avoid interference of the glass wool layer 19 with the rotation of the first bevel gear 7 and the second bevel gear 8.

[0038] Specifically, there are at least three rows of internal support adjustment components, with two rows located near the port of the inner tube 1 and one row located in the middle of the inner tube 1. This arrangement can provide balanced support for the inner tube 1, making the inner tube 1 more securely installed inside the outer tube 2.

[0039] A manufacturing process for steel-cased insulated pipes includes the following steps:

[0040] S1. Material selection: Inner tube 1 and outer tube 2 are made of Q235B material. The outer surface is derusted to remove steel scale, grease, dust, paint, water and other contaminants.

[0041] S2. Aluminum foil is wrapped around the outer wall of inner tube 1: The reserved areas at both ends of inner tube 1 are not wrapped with aluminum foil. Two layers of aluminum foil are wrapped directly at the beginning and end ends, with a 30-40mm edge pressing and the seam is fixed with tape.

[0042] S3: Install the internal support adjustment mechanism: Prefabricate the internal support adjustment mechanism. First, mark the positioning on the outer wall of the inner tube 1. Wrap a layer of high-temperature resistant nanomaterial around the marked positioning point on the inner tube 1, and then wrap a layer of asbestos insulation felt. The two layers overlap to form an insulation pad. Arrange multiple sets of internal support adjustment mechanisms in a ring shape at the marked positions in the middle of the outer wall of the inner tube 1 and near the port of the inner tube 1. Adjust the internal support adjustment mechanisms so that the corresponding internal support adjustment mechanisms arranged along the axis of the inner tube 1 are collinear, and the deviation of the internal support adjustment mechanisms on the same straight line is less than 0.3mm. Weld or bolt the straightened internal support adjustment mechanism to the outer wall of the inner tube 1.

[0043] S4, Glass wool layer 19 filling: Glass wool is required to be straight-wound, each layer of glass wool is tied with No. 18 iron wire at a spacing of 600mm; the last layer of glass wool away from the center of inner tube 1 is covered with plastic film;

[0044] S5. Inner wall treatment of outer tube 2: Aluminum foil reflective cloth is bonded to the inner wall of outer tube 2. The aluminum foil reflective cloth is pressed at the edge by 30-40mm and fixed with tape.

[0045] S6. Insulation layer 4 diameter reduction treatment: Pass the drive pressure rod 3 through the inner support adjustment mechanism on the same straight line, and gradually rotate and adjust the drive pressure rod 3. The pressure rod presses the insulation layer 4 closer to the center of the inner tube 1 until the outer diameter of the insulation layer 4 is 50-60mm smaller than the inner diameter of the outer tube 2.

[0046] S7. Assembly of inner tube 1 and outer tube 2: Using hoisting equipment or forklift, insert one end of inner tube 1 into the port of outer tube 2. Adjust the distance between the two ends of inner tube 1 and outer tube 2 so that the two ends of outer tube 2 are equidistant from the two ends of inner tube 1. Adjust the inner support adjustment mechanism until the central axis of inner tube 1 and outer tube 2 is collinear and the deviation of the central axis of inner tube 1 and outer tube 2 is ≤5mm.

[0047] S8. The outer wall of the outer pipe 2 is treated with anti-corrosion coating. Epoxy coal tar pitch is applied according to the specific anti-corrosion design requirements. The thickness of the epoxy coal tar pitch anti-corrosion layer is greater than or equal to 300μm.

[0048] Through the above production process, the production efficiency of steel-jacketed insulated pipes of the same specification can be increased by 20%-30%, and the damage rate of insulation layer 4 can be reduced to below 0.5%, which can effectively improve the production quality of steel-jacketed insulated pipes while improving production efficiency.

[0049] It should be noted that the terms "one embodiment," "embodiment," "exemplary embodiment," "some embodiments," etc., mentioned in the specification indicate that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge scope of those skilled in the art.

[0050] It should be readily understood that the terms “on,” “above,” and “on top of” in this disclosure should be interpreted in the broadest possible sense, such that “on” means not only “directly on something” but also “on something” with an intermediate feature or layer therebetween, and that “above” or “on top of” means not only “on top of something” but also “on top of something” without an intermediate feature or layer therebetween (i.e., directly on something).

[0051] Furthermore, for ease of explanation, spatially relative terms such as "below," "below," "under," "above," and "above" may be used to describe the relationship of one element or feature relative to other elements or features as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation other than those shown in the figures. The device may have other orientations (rotated 90 degrees or in other orientations), and the spatially relative descriptive terms used herein may be interpreted accordingly.

[0052] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A steel-in-steel insulating pipe, characterized by, The utility model relates to a kind of heat preservation pipe, including inner tube (1), outer tube (2), multiple rows of inner support adjustment assembly and multiple groups of driving pressure rod (3), the inner tube (1) and outer tube (2) are filled with heat preservation layer (4) between, multiple rows of inner support adjustment assembly are equidistantly distributed between the inner tube (1) and outer tube (2), the inner support adjustment assembly includes multiple groups of inner support adjustment mechanism, multiple groups of the inner support adjustment mechanism are circumferentially distributed on the outer wall of inner tube (1), the inner support adjustment mechanism includes U-shaped seat (5), lifting seat (6), first bevel gear (7), second bevel gear (8) and screw rod (9), the U-shaped seat (5) is fixedly installed on the outer wall of inner tube (1), the lifting seat (6) is arranged on U-shaped seat (5) and is slid up and down on the outer wall of inner tube (1), the first bevel gear (7) and the second bevel gear (8) are rotatably installed on the lifting seat (6), the screw rod (9) is fixedly connected with the first bevel gear (7), the screw rod (9) is screwed on U-shaped seat (5), the driving pressure rod (3) is drivingly connected with the second bevel gear (8) on the line of multiple groups of inner support adjustment assembly, the first bevel gear (7) and the second bevel gear (8) are engaged.

2. The steel-in-steel pipe of claim 1, wherein The U-shaped seat (5) is fixedly installed with symmetrically arranged support rods (10), and a ball (11) is rotatably installed at the end of the end portion of the support rod (10) away from the center of the inner tube (1).

3. The steel-in-steel pipe of claim 2, wherein An arc-shaped plate (12) is provided on the top of the lifting seat (6), and an anti-skid pattern (13) is provided on the arc-shaped plate (12).

4. The steel-in-steel pipe of claim 3, wherein A screw cap (14) is provided at the end of the driving pressure rod (3).

5. The steel-in-steel pipe of claim 4, wherein A cross-shaped slot (15) is provided on the second bevel gear (8), and a cross-shaped protrusion (16) is provided on the driving pressure rod (3) and fits with the cross-shaped slot (15), and the cross-shaped protrusion (16) is inserted into the cross-shaped slot (15).

6. The steel-in-steel pipe of claim 5, wherein The lifting seat (6) is provided with a mounting cavity (17), and the first bevel gear (7) and the second bevel gear (8) are rotatably installed in the mounting cavity (17).

7. The steel-in-steel pipe of claim 6, wherein The multiple rows of inner support adjustment assemblies are at least three rows, two of which are located near the ports of the inner tube (1), and one is located in the middle of the inner tube (1).

8. A production process for manufacturing the steel-in-steel thermal insulation pipe according to any one of claims 1 to 7, characterized in that, The utility model includes the following steps: S1, material selection: Q235B material is selected for the inner tube (1) and the outer tube (2), the outer surface is rusted, and the rolled steel scale, grease, dust, paint, water and other contaminants are removed; S2, winding aluminum foil on the outer wall of the inner tube (1): the two end reserved areas of the inner tube (1) are not wrapped with aluminum foil, the starting and ending two ends are straightly wound with two layers of aluminum foil, the edge is pressed by 30-40mm, and is fixed with adhesive tape. S3: Install the inner support adjustment mechanism: prefabricate the inner support adjustment mechanism, first mark the position on the outer wall of the inner tube (1), then wrap a layer of high-temperature-resistant nanometer material on the marked position, and then wrap a layer of asbestos heat insulation felt, and the two layers are overlapped to form a heat insulation pad; arrange multiple groups of inner support adjustment mechanisms in a ring shape on the outer wall of the inner tube (1) at the middle and near the port of the inner tube (1), adjust the inner support adjustment mechanism, so that the corresponding inner support adjustment mechanisms arranged along the axis of the inner tube (1) are collinear, and the deviation of the inner support adjustment mechanisms on the same straight line is less than 0.3mm; weld or bolt connect the straightened inner support adjustment mechanism with the outer wall of the inner tube (1); S4, glass wool layer filling: glass wool requires straight winding, each layer of glass wool is bundled with No. 18 iron wire, and the spacing is 600mm; the last layer of glass wool away from the center of the inner tube (1) is covered by plastic film; S5, outer tube (2) inner wall treatment: aluminum foil reflective cloth is adhered to the inner wall of the outer tube (2), the aluminum foil reflective cloth is pressed 30-40mm, and the joint is fixed with adhesive tape; S6, heat preservation layer (4) diameter reduction treatment: pass the driving pressure rod (3) through the inner support adjustment mechanism on the same straight line, gradually rotate and adjust the driving pressure rod (3), drive the heat preservation layer (4) to move towards the center of the inner tube (1), until the outer diameter of the heat preservation layer (4) is less than 50-60mm of the inner diameter of the outer tube (2); S7, inner tube (1) and outer tube (2) assembly: through hoisting equipment or forklift, insert one end of the inner tube (1) into the port of the outer tube (2), adjust the distance between the two ends of the inner tube (1) and the outer tube (2), so that the two ends of the outer tube (2) are equidistant from the two ends of the inner tube (1), adjust the inner support adjustment mechanism, until the center axes of the inner tube (1) and the outer tube (2) are collinear, continue to rotate and adjust the driving pressure rod (3), move the driving pressure rod (3) away from the center axis of the inner tube (1), until the inner support adjustment mechanism is tightly clamped with the inner wall of the outer tube (2); the deviation of the center axes of the inner tube (1) and the outer tube (2) is less than or equal to 5mm; S8, outer tube (2) outer wall corrosion prevention treatment, according to the specific corrosion prevention design requirement, brush epoxy coal tar anticorrosive, the thickness of the epoxy coal tar anticorrosive layer is greater than or equal to 300μm.

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