A device for preheating and hydrogen removal at the horizontal welding position of a large-diameter, thick-walled pipe.

Abstract

This utility model discloses a preheating and hydrogen removal device for the horizontal welding position of a large-diameter thick-walled pipe, including a temperature control device, a clamping device, and a fixed support device. The fixed support device includes a base and a main rod mounted on the base. The clamping device includes an upper plate, a lower plate, a support column, a baffle, an upper support rod, a lower support rod, a clamping nut, and a sleeve. The center of the upper plate is fixedly connected to the top of the main rod, and the upper and lower plates are fixedly connected by the support column. The baffle is composed of multiple pieces, each of which is hinged to the upper plate and the sleeve by the upper and lower support rods, respectively. The bottom end of the sleeve is rotatably connected to a clamping nut, which is threadedly connected to the main rod. The temperature control device includes an insulation layer and a heating layer. The heating layer is annularly sleeved on the outside of the baffle between the upper and lower plates, and the insulation layer is located on the inside and both sides of the heating layer. This utility model achieves uniform preheating, reduces measurement time during manual positioning, lowers the skill level requirements for operators, facilitates hydrogen removal operation, and solves problems such as poor fit.

Description

Technical Field

[0001] This utility model relates to the field of welding auxiliary equipment manufacturing technology, and in particular to a device for preheating and hydrogen removal at the horizontal welding position of a large-diameter thick-walled pipe. Background Technology

[0002] Preheating involves locally or entirely heating the base material (usually to 100-300°C) before welding to reduce the cooling rate of the weld and heat-affected zone, preventing hardened structures (such as martensite) and residual stress concentration caused by rapid cooling. This helps suppress cold cracking, improves the weldability of the material, reduces the temperature difference between the molten pool and the base material, avoids lamellar tearing caused by uneven thermal shrinkage (such as in thick plate T-joints), and simultaneously improves the weld fusion quality.

[0003] Post-Weld Hydrogen Baking involves immediately after welding and holding the weld at a low temperature (300~400℃) for an extended period (2~6 hours). This accelerates the diffusion and escape of hydrogen atoms, eliminating the risk of hydrogen-induced delayed cracking (HDC). For highly sensitive applications such as high-strength steel (≥690MPa) and thick plates (>50mm), post-weld hydrogen baking can mitigate the risk of hydrogen enrichment at grain boundaries, forming a closed-loop hydrogen control system in conjunction with preheating.

[0004] In pressure vessels, there are welded joints between the strut-type nozzles and the shell, as well as between some large-diameter nozzles and the header. Due to structural reasons, the welding position is a horizontal weld. Traditional processes have the following defects:

[0005] 1. Uneven preheating: The large temperature gradient of the flame heating (local temperature difference exceeding ±50℃) leads to coarsening of the grains in the heat-affected zone of the weld.

[0006] 2. Difficulty in hydrogen removal: Hydrogen removal requires secondary clamping equipment, with a process interval of more than 2 hours, which significantly increases the risk of hydrogen-induced cracking (cold cracking rate ≥3‰).

[0007] 3. Poor fit: Conventional heating blankets have less than 60% contact area with curved surfaces, resulting in a thermal efficiency of less than 40%. Utility Model Content

[0008] To solve the above-mentioned technical problems, this utility model designs a device for preheating and hydrogen removal at the horizontal welding position of a large-diameter thick-walled nozzle. It is an integrated device for preheating before welding and removing hydrogen after welding at the horizontal welding position of a thick-walled nozzle with an inner diameter (DN≥380mm) (wall thickness≥30mm) in a pressure vessel.

[0009] The present invention adopts the following technical solution:

[0010] A device for preheating and hydrogen removal at the horizontal welding position of a large-diameter thick-walled pipe includes a temperature control device, a clamping device, and a fixing support device.

[0011] The fixed support device includes a base and a main rod installed on the base;

[0012] The clamping device includes an upper plate, a lower plate, a support column, a baffle, an upper support rod, a lower support rod, a clamping nut, and a sleeve. The center of the upper plate is fixedly connected to the top of the main rod. The upper plate and the lower plate are fixedly connected by the support column. The baffle consists of multiple pieces arranged between the upper plate and the lower plate. Each baffle has an upper support rod and a lower support rod hinged to its upper and lower parts, respectively. The other end of the upper support rod is hinged to the upper plate, and the other end of the lower support rod is hinged to the sleeve. The sleeve is fitted onto the main rod, and a clamping nut is rotatably connected to the bottom end of the sleeve. The clamping nut is threadedly connected to the main rod.

[0013] The temperature control device includes an insulation layer and a heating layer. The heating layer is ring-shaped and sleeved on the outside of the baffle between the upper and lower plates. The insulation layer is located inside and on both the upper and lower sides of the heating layer, isolating the heating layer from the various device components. This prevents damage to other parts during long-term use.

[0014] Preferably, the upper end of the base is rotatably connected to an adjusting nut, which is threadedly connected to the main rod.

[0015] Preferably, the baffle consists of four baffles. These baffles clamp simultaneously in all directions, ensuring uniform force distribution around the perimeter and promoting a tight fit between the heating layer and the circumferential weld, resulting in even force distribution.

[0016] Preferably, the two hinged positions connecting the upper and lower support rods on the baffle are located on the same axial straight line and at the trisection points, and do not overlap.

[0017] Preferably, the four hinge positions on the sleeve connecting to the lower support rod are arranged at the same height and are evenly distributed around the center line at a 90° axial angle.

[0018] Preferably, the four hinge positions on the upper plate that connect to the upper support rod are arranged at the same height and are evenly distributed around the center line at 90°, and are on the same axis as the four hinge positions on the sleeve.

[0019] Preferably, the sleeve and the main rod are connected by a sliding groove.

[0020] Preferably, the height adjustment nut is welded with a lower handle.

[0021] Preferably, the clamping nut is welded with an upper handle.

[0022] Preferably, the base is a tripod base.

[0023] The beneficial effects of this utility model are: This utility model designs a preheating and hydrogen removal device for the horizontal welding position of a large-diameter thick-walled pipe, which achieves uniform preheating, reduces the measurement time during manual positioning, lowers the skill level requirements of operators, facilitates hydrogen removal operation, and solves problems such as poor fit. Attached Figure Description

[0024] Figure 1 This is a diagram showing one usage state of this utility model;

[0025] Figure 2 This is a schematic diagram of the internal structure of this utility model;

[0026] Figure 3 yes Figure 1 A partial usage status diagram in the image;

[0027] Figure 4 This is a schematic diagram of the external structure of this utility model;

[0028] In the diagram: 1. Base, 2. Main rod, 3. Lower handle, 4. Adjusting nut, 5. Clamping nut, 6. Upper handle, 7. Sleeve, 8. Lower plate, 9. Lower support rod, 10. Baffle, 11. Upper support rod, 12. Support column, 13. Upper plate, 14. Insulation layer, 15. Heating layer, 16. Collection box, 17. Connecting pipe. Detailed Implementation

[0029] The technical solution of this utility model will be further described in detail below through specific embodiments and with reference to the accompanying drawings:

[0030] Example: Figure 2 and Figure 4 As shown, a device for preheating and hydrogen removal at the horizontal welding position of a large-diameter thick-walled pipe includes a temperature control device, a clamping device, and a fixing support device.

[0031] The fixed support device includes a base 1 and a main rod 2 mounted on the base;

[0032] The clamping device includes an upper plate 13, a lower plate 8, a support column 12, a baffle 10, an upper support rod 11, a lower support rod 9, a clamping nut 5, and a sleeve 7. The center of the upper plate is fixedly connected to the top of the main rod. The upper and lower plates are fixedly connected by the support column. There are four baffles arranged between the upper and lower plates. Each baffle has an upper support rod and a lower support rod hinged to its upper and lower parts, respectively. The other end of the upper support rod is hinged to the upper plate, and the other end of the lower support rod is hinged to the sleeve. The sleeve is fitted onto the main rod, and the bottom end of the sleeve is rotatably connected to the clamping nut, which is threaded to the main rod. By adjusting the clamping nut upwards, the clamping nut pushes the sleeve upwards and transmits the clamping force to the baffles through the upper and lower support rods. This pushes the four baffles outwards simultaneously, ensuring uniform force distribution around the perimeter and promoting tight adhesion between the heated layer and the circumferential weld, resulting in uniform force distribution.

[0033] The temperature control device includes an insulation layer 14 and a heating layer 15. The heating layer is annularly fitted outside the baffle between the upper and lower plates. The insulation layer is located inside and on both the upper and lower sides of the heating layer, isolating the heating layer from the various device components. This prevents damage to other parts during long-term use.

[0034] The upper end of the base is rotatably connected to an adjusting nut 4, which is threadedly connected to the main rod.

[0035] The two hinged positions connecting the upper and lower support rods on the baffle are located on the same axial straight line and at the trisection points, and do not coincide.

[0036] The four hinge points on the sleeve connecting to the lower support rod are arranged at the same height and evenly distributed axially around the center line at 90°. The four hinge points on the upper plate connecting to the upper support rod are arranged at the same height and evenly distributed axially around the center line at 90°, and are on the same axis as the four hinge points on the sleeve.

[0037] The sleeve and the main rod are connected by a sliding groove. A lower handle (3) is welded to the height adjustment nut. An upper handle (6) is welded to the clamping nut. The base is a tripod base.

[0038] like Figure 2 The diagram shown is an overall view of the preheating and hydrogen removal device at the horizontal welding position of the large-diameter thick-walled nozzle. Figure 1 This is an assembly drawing of the preheating and hydrogen removal device for the horizontal welding position of the large-diameter thick-walled nozzle and the bevel (the bevel between header 16 and nozzle 17). It shows the contact situation between the heating layer and the bevel (the bevel between header 16 and nozzle 17) after assembly, as follows: Figure 3 As shown. The specific assembly operations are as follows:

[0039] First, the preheating and hydrogen removal device for the horizontal welding position of the large-diameter thick-walled pipe is placed directly below the pipe 17 via the base 1 to achieve initial positioning.

[0040] Secondly, by rotating the lower handle 3, the height adjustment nut 4 is rotated in the opposite direction, causing the main rod 2 and other upper parts to move upward, adjusting the position of the heating layer 15 and the bevel in the height direction, and adjusting the bevel to the middle of the heating layer.

[0041] Finally, by rotating the upper handle 6, the clamping nut 5 is driven to move upward, and the sleeve 7 is pushed upward, which increases the angle between the lower support rod 9 and the main rod 2 and the angle between the upper support rod and the main rod 2, thereby pushing the baffle 10 outward, so that the insulation layer 14 is in close contact with the heating layer 15, and the heating layer 15 is in close contact with the bevel (the bevel between the header 16 and the pipe 17).

[0042] This preheating and hydrogen removal device for the horizontal welding position of large-diameter thick-walled pipes enables preheating and hydrogen removal at the horizontal welding position, facilitating the installation of the heating device and the bevel weld. It achieves uniform preheating, reduces measurement time during manual positioning, lowers the skill level requirements for operators, and facilitates hydrogen removal, resolving issues such as poor fit.

[0043] The embodiments described above are merely preferred solutions of this utility model and are not intended to limit this utility model in any way. Other variations and modifications are possible without departing from the technical solutions described in the claims.

Claims

1. A device for preheating and hydrogen removal at the horizontal welding position of a large-diameter, thick-walled nozzle, characterized in that, It includes a temperature control device, a clamping device, and a fixing support device; The fixed support device includes a base and a main rod installed on the base; The clamping device includes an upper plate, a lower plate, a support column, a baffle, an upper support rod, a lower support rod, a clamping nut, and a sleeve. The center of the upper plate is fixedly connected to the top of the main rod. The upper plate and the lower plate are fixedly connected by the support column. The baffle consists of multiple pieces arranged between the upper plate and the lower plate. Each baffle has an upper support rod and a lower support rod hinged to its upper and lower parts, respectively. The other end of the upper support rod is hinged to the upper plate, and the other end of the lower support rod is hinged to the sleeve. The sleeve is fitted onto the main rod, and a clamping nut is rotatably connected to the bottom end of the sleeve. The clamping nut is threadedly connected to the main rod. The temperature control device includes an insulation layer and a heating layer. The heating layer is ring-shaped and sleeved on the outside of the baffle between the upper and lower plates. The insulation layer is located inside and on the upper and lower sides of the heating layer, isolating the heating layer from the device components.

2. The device for preheating and hydrogen removal at the horizontal welding position of a large-diameter thick-walled pipe according to claim 1, characterized in that, The upper end of the base is rotatably connected to an adjusting nut, which is threadedly connected to the main rod.

3. The device for preheating and hydrogen removal at the horizontal welding position of a large-diameter thick-walled pipe according to claim 1, characterized in that, The baffle consists of four baffles.

4. The device for preheating and hydrogen removal at the horizontal welding position of a large-diameter thick-walled pipe according to claim 1, characterized in that, The two hinged positions on the baffle connecting the upper and lower support rods are located on the same axial straight line and at the trisection points, and do not overlap.

5. A preheating and hydrogen removal device for the horizontal welding position of a large-diameter thick-walled nozzle according to claim 3, characterized in that, The four hinged positions on the sleeve that connect to the lower support rod are arranged at the same height and are evenly distributed around the center line at a 90° axial angle.

6. A preheating and hydrogen removal device for the horizontal welding position of a large-diameter thick-walled pipe according to claim 5, characterized in that, The four hinge positions on the upper plate that connect to the upper support rod are arranged at the same height and are evenly distributed around the center line at 90°, and are on the same axis as the four hinge positions on the sleeve.

7. A device for preheating and hydrogen removal at the horizontal welding position of a large-diameter thick-walled pipe according to claim 1, characterized in that, The sleeve and the main rod are connected by a sliding groove.

8. A device for preheating and hydrogen removal at the horizontal welding position of a large-diameter thick-walled pipe according to claim 2, characterized in that, A lower handle is welded onto the height adjustment nut.

9. A device for preheating and hydrogen removal at the horizontal welding position of a large-diameter thick-walled pipe according to claim 1, characterized in that, The clamping nut is welded with an upper handle.

10. A device for preheating and hydrogen removal at the horizontal welding position of a large-diameter thick-walled pipe according to claim 1, characterized in that, The base is a tripod base.

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