Manufacturing process of serpentine heating coil

Abstract

The application discloses a manufacturing process of a serpentine heating coil pipe. The manufacturing process of the serpentine heating coil pipe comprises the following steps: S1, material preparation; S2, forming; and S3, welding. The application solves the problem that the prior art has more butt welds, which not only increases the quality risk caused by welding defects of the welds, but also increases the welding material usage and the labor cost of welders.

Description

Technical Field

[0001] This invention relates to the field of marine technology, and in particular to a manufacturing process for a serpentine heating coil. Background Technology

[0002] Snake-shaped heating coils are used in various oil and water tanks (including liquid cargo tanks) on ships that require heating. For example... Figure 1-2 As shown, currently, in the production of serpentine heating coils, 6-meter straight steel pipes are bent into unit fittings with one bend, and then the unit fittings are arranged in sequence for butt welding. However, the final product has many butt welds, which not only increases the quality risk caused by weld defects, but also increases the amount of welding materials used and the labor cost of welders. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the purpose of this invention is to provide a manufacturing process for a serpentine heating coil that reduces the quality risks caused by welding defects, while also reducing the amount of welding materials used and the labor costs of welders.

[0004] To achieve the above objectives, the technical solution adopted in the manufacturing process of the serpentine heating coil of the present invention is as follows:

[0005] A manufacturing process for a serpentine heating coil includes the following steps:

[0006] S1. Material preparation: Prepare several straight steel pipes, each 9-12 meters long, for making unit pipe fittings. Each unit pipe fitting includes a first straight edge segment. One end of the first straight edge segment is bent into a first elbow. One end of the first elbow is connected to the first straight edge segment, and the other end naturally forms a second straight edge segment. The other end of the first straight edge segment is bent into a second elbow. The second elbow turns to the opposite side of the first elbow. One end of the second elbow is connected to the first straight edge segment, and the other end naturally forms a third straight edge segment. The length of the third straight edge segment is greater than that of the second straight edge segment and less than that of the first straight edge segment. The sum of the lengths of the second and third straight edge segments is equal to the length of the first straight edge segment.

[0007] S21. Equipment preparation: pipe bending machine and follow-up trolley;

[0008] S22, Springback angle adjustment;

[0009] S23. Make the first bend: Use a pipe bending machine to bend the pipe to make the first bend;

[0010] S24. Bending out the second bend: Loosen the semi-finished unit pipe on the pipe bending machine, extend the first bend outwards of the pipe bending machine by an appropriate distance, rotate the first straight edge section so that the first bend rotates 180°, use the follow-up carriage to fix the first straight edge section close to the side of the first bend, and then use the pipe bending machine to bend out the second bend.

[0011] S3. Welding: The pipe opening of the third straight edge section of the previous unit fitting is butt-welded to the pipe opening of the second straight edge section of the next unit fitting, until the welding of all unit fittings is completed.

[0012] Preferably, the follower trolley includes a frame, the bottom surface of which is provided with a plurality of casters, the top surface of which is provided with a groove for storing the first straight edge segment, and a plurality of screws are provided on both sides of the groove on the top surface of the frame. A pressure plate is sleeved on the outside of the screws, and an upper groove is provided on the bottom surface of the pressure plate. A nut is connected to one side of the screw that passes through the pressure plate. The nut squeezes the pressure plate, causing the upper groove and the lower groove to cooperate and lock the first straight edge segment.

[0013] Preferably, the side wall of the frame is provided with a bracket, and the top surface of the bracket is at the same horizontal plane as the lowest point of the lower groove.

[0014] Preferably, the bracket has distance scale lines on both sides along the axis of the lower groove, and the zero point of the distance scale lines is flush with the side wall of the bracket.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] 1. The original single-bend component was changed to a double-bend component, thereby reducing the number of butt welds. This not only reduced the quality risks caused by weld defects, but also reduced the amount of welding materials used and the labor costs for welders.

[0017] 2. When forming the second bend, use a follow-up trolley instead of an assistant to support the first straight edge section on one side of the first bend to improve safety.

[0018] 3. The top surface of the bracket on the side wall of the frame is on the same horizontal plane as the lowest point of the lower groove, which can quickly "level" the surface, thus ensuring that the first bend and the second bend are on the same horizontal plane.

[0019] 4. Set distance scale lines on both sides of the bracket along the axis of the lower groove. The position of the two distance scale lines on the outer wall of the second straight edge section can be measured with the help of a square. The anti-rebound angle set by the pipe bending machine can be adjusted according to the deviation. Attached Figure Description

[0020] Figure 1 This is a distribution diagram of the butt weld seams of existing serpentine heating coils;

[0021] Figure 2 This is a structural schematic diagram of an existing technology unit pipe fitting;

[0022] Figure 3 This is a flowchart of the manufacturing process of the serpentine heating coil of the present invention;

[0023] Figure 4 This is a structural schematic diagram of the unit tube of the present invention;

[0024] Figure 5 This is a schematic diagram of the structure of the follower vehicle of the present invention;

[0025] Figure 6 This is a schematic diagram of the operation of the follow-up trolley participating in the springback angle adjustment of the present invention;

[0026] Figure 7 This is a calculation principle diagram for adjusting the rebound angle;

[0027] Figure 8 This is a schematic diagram of the working process of the follower trolley participating in the forming of the second bend in this invention;

[0028] Figure 9 This is a distribution diagram of the butt weld seams of the serpentine heating coil of the present invention.

[0029] Among them, 1 is the unit pipe fitting, 11 is the first straight edge section, 12 is the first elbow, 13 is the second straight edge section, 14 is the second elbow, 15 is the third straight edge section, 2 is the follower trolley, 21 is the frame, 22 is the caster wheel, 23 is the lower groove, 24 is the screw, 25 is the pressure plate, 26 is the upper groove, 27 is the nut, 28 is the bracket, 29 is the distance scale line, and 3 is the square. Detailed Implementation

[0030] The present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. After reading this invention, any modifications of the invention in various equivalent forms by those skilled in the art will fall within the scope defined by the appended claims.

[0031] like Figure 3-9 As shown, the manufacturing process of a serpentine heating coil includes the following steps:

[0032] S1. Material preparation: Prepare several straight steel pipes, each 9-12 meters long, for making unit pipe fitting 1. The unit pipe fitting includes a first straight edge segment 11, one end of which is bent into a first elbow 12. One end of the first elbow is connected to the first straight edge segment, and the other end naturally forms a second straight edge segment 13. The other end of the first straight edge segment is bent into a second elbow 14, which turns to the opposite side of the first elbow. One end of the second elbow is connected to the first straight edge segment, and the other end naturally forms a third straight edge segment 15. The length of the third straight edge segment is greater than that of the second straight edge segment and less than that of the first straight edge segment, and the sum of the lengths of the second and third straight edge segments is equal to the length of the first straight edge segment.

[0033] S2, Molding:

[0034] S21. Equipment preparation: Pipe bending machine and follower trolley 2. The pipe bending machine is purchased from the market and is existing technology. The follower trolley is a self-made tooling. The follower trolley includes a frame 21. Four universal wheels 22 are installed on the bottom surface of the frame. A groove 23 is opened on the top surface of the frame to store the first straight edge segment. Two screws 24 are welded on each side of the groove on the top surface of the frame. A pressure plate 25 is sleeved on the outside of the screw. An upper groove 26 is opened on the bottom surface of the pressure plate. A nut 27 is connected to the side of the screw that passes through the pressure plate. The nut squeezes the pressure plate, causing the upper groove and the lower groove to cooperate and lock the first straight edge segment. A bracket 28 is welded to the side wall of the frame. The top surface of the bracket is at the same level as the lowest point of the lower groove. Distance scale lines 29 are marked on both sides of the bracket along the axis of the lower groove. The zero point of the distance scale line is flush with the side wall of the bracket.

[0035] S22, Springback angle adjustment;

[0036] S221. Set the initial springback angle for the pipe bending machine based on experience;

[0037] S222. Use a pipe bending machine to bend one end of a straight steel pipe into the first bend.

[0038] S223. Remove the workpiece from S222, place the first straight edge into the lower groove, place the second straight edge on the top surface of the bracket, and put the pressure plate on the outside of the screw. Tighten it with the nut, and the upper groove and lower groove cooperate to lock the first straight edge.

[0039] S224. Using square 3, one right-angled side of the square is in contact with the top surface of the bracket, and the other right-angled side is against the outer circumference of the second right-angled section. Using the distance scale, read the distance from the right angle of the square to the zero point at points A and B on the second right-angled section. When there is a difference between the distances from points A and B to the zero point, use the Pythagorean theorem to calculate the angle that needs to be adjusted, so as to obtain the final springback angle that the pipe bending machine needs to be set in one go.

[0040] S23. Make the first bend: Use a pipe bending machine to bend the pipe to make the first bend;

[0041] S24. Bending out the second bend: Loosen the semi-finished unit pipe on the pipe bending machine, extend the first bend outwards of the pipe bending machine by an appropriate distance, rotate the first straight edge section so that the first bend rotates 180°, and the second straight edge section is on the top surface of the bracket. The top surface of the bracket and the lowest point of the lower groove are on the same horizontal plane, which can quickly "level" the bend, thus ensuring that the first bend and the second bend are on the same horizontal plane. The side of the first straight edge section that is close to the first bend falls into the lower groove, and the pressure plate is put on the outside of the screw and locked with a nut. The upper groove and the lower groove cooperate to lock the first straight edge section. Then, use the pipe bending machine to bend out the second bend. When bending the second bend, since the first bend extends a long distance out of the pipe bending machine, it needs to be supported. Manual support is dangerous. Therefore, a follow-up trolley is used to support the first straight edge section on one side of the first bend instead of an assistant to improve safety.

[0042] S3. Welding: The pipe opening of the third straight edge section of the previous unit fitting is butt-welded to the pipe opening of the second straight edge section of the next unit fitting, until the welding of all unit fittings is completed.

[0043] This invention uses a longer straight steel pipe to change the original single-bend component to a double-bend component, thereby reducing the number of butt welds by half. This reduces the quality risk caused by weld defects, as well as the amount of welding materials used and the labor cost of welders.

Claims

1. A manufacturing process for a serpentine heating coil, characterized in that, Includes the following steps: S1. Material preparation: Prepare several straight steel pipes, each 9-12 meters long, for making unit pipe fittings. Each unit pipe fitting includes a first straight edge segment. One end of the first straight edge segment is bent into a first elbow. One end of the first elbow is connected to the first straight edge segment, and the other end naturally forms a second straight edge segment. The other end of the first straight edge segment is bent into a second elbow. The second elbow turns to the opposite side of the first elbow. One end of the second elbow is connected to the first straight edge segment, and the other end naturally forms a third straight edge segment. The length of the third straight edge segment is greater than that of the second straight edge segment and less than that of the first straight edge segment. The sum of the lengths of the second and third straight edge segments is equal to the length of the first straight edge segment. S2, Molding: S21. Equipment preparation: pipe bending machine and follow-up trolley; S22, Springback angle adjustment; S23. Make the first bend: Use a pipe bending machine to bend the pipe to make the first bend; S24. Bending out the second bend: Loosen the semi-finished unit pipe on the pipe bending machine, extend the first bend outwards of the pipe bending machine by an appropriate distance, rotate the first straight edge section so that the first bend rotates 180°, use the follow-up carriage to fix the first straight edge section close to the side of the first bend, and then use the pipe bending machine to bend out the second bend. S3. Welding: The pipe opening of the third straight edge section of the previous unit fitting is butt-welded to the pipe opening of the second straight edge section of the next unit fitting, until the welding of all unit fittings is completed.

2. The manufacturing process of the serpentine heating coil according to claim 1, characterized in that: The follower trolley includes a frame with several casters on the bottom surface and a groove for storing the first straight edge segment on the top surface of the frame. Several screws are arranged on both sides of the groove on the top surface of the frame. A pressure plate is sleeved on the outside of the screws. An upper groove is formed on the bottom surface of the pressure plate. A nut is connected to one side of the screw that passes through the pressure plate. The nut squeezes the pressure plate, causing the upper and lower grooves to engage and lock the first straight edge segment.

3. The manufacturing process of the serpentine heating coil according to claim 2, characterized in that: The side wall of the frame is provided with a bracket, and the top surface of the bracket is at the same horizontal plane as the lowest point of the lower groove.

4. The manufacturing process of the serpentine heating coil according to claim 3, characterized in that: The bracket has distance scale lines on both sides along the axis of the lower groove, and the zero point of the distance scale line is flush with the side wall of the bracket.

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