Straight welded pipe preheating device

Abstract

The invention discloses a preheating device for a longitudinal welded pipe, which comprises a heating mechanism comprising a container with an open top surface and stacked with heat conducting sand, and a heat source assembly for heating the heat conducting sand; the modeling mechanism comprises a sand digging assembly arranged above the container and is used for manufacturing an arc-shaped pit in the top face of the heat conduction sand pile, and the arc-shaped pit can be attached to the curved face where the welding seam of the longitudinal welded pipe is located. The heat conduction sand is used for heating, through cooperation of the container and the heat source assembly, heat can be evenly transmitted to the welding seam area of the longitudinal welded pipe, the uniformity of the heating temperature is achieved, the heating thickness of the multi-caliber welded pipe in the preheating process is guaranteed, and the problem of local overheating or insufficient preheating is effectively avoided; a good foundation is provided for a subsequent welding procedure; and the heat conduction sand can be modeled according to the radians of the weld joints of the welded pipes with different calibers through the modeling mechanism, the equipment investment cost and the production space are greatly saved, and good adaptability and economical efficiency are achieved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of metal pipe welding, and particularly relates to a straight seam welded pipe preheating device. BACKGROUND

[0002] In the straight seam welded pipe manufacturing process, the weld preheating process is a key process link to ensure the welding quality. In particular, for large-diameter thick-walled welded pipes, sufficient pre-welding preheating can effectively reduce the cooling speed of the weld area and reduce the hardening tendency of the weld heat-affected zone, which plays a decisive role in preventing welding cracks, reducing residual stress and improving the mechanical properties of the joint. If the preheating process is not properly controlled, micro defects are likely to occur between the weld metal and the base metal, which seriously affects the integrity of the pipe structure and the safety during service.

[0003] At present, in the preheating process of large-diameter straight seam welded pipes, the common preheating methods mainly include truss hoisting heating blankets and clamping heating methods. The truss hoisting heating blanket preheating method has strong operation flexibility, can adapt to various heat sources, and is very convenient to install. The clamping heating method performs outstandingly in terms of contact type heat conduction efficiency.

[0004] However, due to the structural characteristics of large-diameter welded pipes, such as large diameter and thick wall thickness, these existing preheating methods have many drawbacks. The heating method using a truss hoisting heating blanket has limited contact area between the heating blanket and the large-diameter straight seam welded pipe, and the heat source is concentrated on the surface layer. The heat needs to be conducted to the inside through the thermal conductivity of the pipe itself. If the heating time is short or the power is insufficient, the heat will be difficult to penetrate deeply, resulting in shallow heating thickness, which cannot effectively preheat the welded part, and the subsequent joint welding process is not effective. After preheating is completed, the weld needs to be reversed from 12 o'clock to 6 o'clock direction to connect the subsequent inner welding process, which increases the complexity and cost of operation. The clamping heating method uses clamps to fit the outer wall of the welded pipe for heating. Since the welded pipe production line often involves production tasks of multiple different diameters of welded pipes, multiple sets of clamps need to be provided, which not only has low economic efficiency, but also requires frequent replacement of clamps, greatly reducing production efficiency. SUMMARY

[0005] The technical problem to be solved by the present application is to overcome the deficiencies and defects mentioned in the above background art, and to provide a straight seam welded pipe preheating device that has uniform heating temperature, deep heating thickness, simple operation, and meets the preheating of welded seams of welded pipes of various diameters.

[0006] To solve the above technical problems, the technical solution provided by the present application is: The straight seam welded pipe preheating device comprises a heating mechanism and a shaping mechanism, wherein the heating mechanism comprises a container with an open top surface and filled with heat-conducting sand, and a heat source assembly for heating the heat-conducting sand; the shaping mechanism comprises a sand-digging assembly arranged above the container and used for forming an arc-shaped pit on the top surface of the heat-conducting sand pile, and the arc-shaped pit is capable of being fitted to the curved surface of the weld of the straight seam welded pipe.

[0007] In the straight seam welded pipe preheating device, preferably, the shaping mechanism comprises a movable gantry arranged above the container, and the sand-digging assembly is movably arranged on the movable gantry by a first lifting driving member. The movable gantry can provide stable support for the sand-digging assembly and drive the sand-digging assembly to move horizontally to the position to be excavated, and the sand-digging assembly can move vertically on the movable gantry by the first lifting driving member, so that the depth of the arc-shaped pit can be flexibly adjusted according to the depth requirement of the weld of the straight seam welded pipe, the preheating requirement of the straight seam welded pipe of different specifications and sizes is met, and the universality and application range of the device are increased.

[0008] In the straight seam welded pipe preheating device, preferably, the sand-digging assembly comprises a hanger, plough claws and height adjusting members, the plough claws are arranged below the hanger by the height adjusting members respectively, and the plough claws are arranged along the width direction of the straight seam welded pipe. The multiple plough claws can simultaneously work to quickly excavate the required arc-shaped pit on the top surface of the heat-conducting sand pile, the height of the bottom end of each plough claw can be individually adjusted by the height adjusting members according to the straight seam welded pipe of different models, the excavating depth of each plough claw can be accurately controlled, the arc-shaped pit capable of being fitted to the curved surface of the weld of the straight seam welded pipe can be accurately formed, the shape, size and curvature of the arc-shaped pit meet the requirements, and the uniformity and accuracy of the preheating effect are improved.

[0009] In the straight seam welded pipe preheating device, preferably, the height difference H between the bottom end of the plough claw located in the middle and the bottom end of the plough claw located at the most side edge is greater than the thickness of the pipe wall of the straight seam welded pipe. Since the pipe wall of the straight seam welded pipe has a certain thickness, the height difference H is set to be greater than the thickness of the pipe wall, so that the insufficient preheating caused by the too shallow arc-shaped pit can be avoided, the heat can be uniformly transferred to the area where the weld is located during the preheating process, the preheating quality is improved, and better conditions are provided for subsequent welding.

[0010] In the straight seam welded pipe preheating device, preferably, the height adjusting member comprises a connecting member fixedly arranged on the hanger, an adjusting motor arranged on the connecting member, and a driving crank connected with the adjusting motor, the plough claw is connected with the driving crank, and the adjusting motor drives the plough claw to adjust the height through the driving crank. The adjusting motor can accurately control the rotation angle of the driving crank, so as to drive the plough claw to rotate and accurately adjust the height of the bottom end of the plough claw.

[0011] Preferably, the height adjusting member further comprises a spring connected to the connecting member at one end and an arc-shaped connecting rod connected to the other end of the spring, and the plough is connected to the driving crank through the arc-shaped connecting rod. This arrangement changes the single-point connection of the plough and the connecting member to a double-point connection, making the plough more stable in use.

[0012] Preferably, the container is provided with guide rails on both sides along the length direction of the straight seam welded pipe, and the movable gantry comprises a plurality of vertical columns, and the lower end of each vertical column is provided with a driving wheel matched with the guide rails. The guide rails and the driving wheels provide a stable moving path for the movable gantry, ensuring that the gantry does not deviate or shake during movement, accurately guiding the moving direction of the gantry, and ensuring that the sand digging assembly can accurately create an arc-shaped pit on the top surface of the heat-conducting sand pile.

[0013] Preferably, the heat source assembly comprises a plurality of gas guide channels arranged below the container along the length direction of the straight seam welded pipe, a plurality of flame nozzles arranged on the gas guide channels, and an igniter arranged on the gas guide channels. The gas guide channels serve as a support and gas conveying channel, and the plurality of flame nozzles are distributed thereon to ensure that the heat-conducting sand arranged above can be uniformly heated over a large area.

[0014] Preferably, the heating mechanism further comprises a plurality of centrifugal vibrators arranged on the inner bottom surface of the container through a fixed plate. The centrifugal vibrators can vibrate the container to restore the heat-conducting sand to a flat and compact state, so that the heat-conducting sand can quickly return to the initial unshaped state when the straight seam welded pipe needs to be changed in size, reducing the complexity and labor intensity of manual operation and improving the work efficiency.

[0015] Preferably, the straight seam welded pipe preheating device further comprises a hoisting mechanism, the hoisting mechanism comprises a group of hoisting frames arranged at intervals along the length direction of the straight seam welded pipe, and a magnetic attraction assembly arranged along the length direction of the straight seam welded pipe, the hoisting frames are arranged above the container, the magnetic attraction assembly is arranged on the hoisting frames and can move horizontally along the width direction of the straight seam welded pipe, and the magnetic attraction assembly comprises a magnetic attraction member and a second lifting driving member for driving the magnetic attraction member to lift. By arranging the hoisting mechanism, the straight seam welded pipe can be automatically hoisted and unloaded, reducing manual operation and improving production efficiency and safety. The magnetic attraction assembly can attract straight seam welded pipes of different lengths and diameters, enhancing its adaptability.

[0016] Compared with the prior art, the advantages of the present application are: This invention utilizes thermally conductive sand to preheat straight seam welded pipes through the cooperation of a container and a heat source assembly. Because the thermally conductive sand acts as an insulation medium, it stores heat for a long time and releases it slowly. The gaps between the sand particles create a uniform thermal environment, allowing heat to gradually diffuse into the straight seam welded pipe through heat conduction and convection. Its insulation properties extend the heating time, ensuring that deeper materials are fully heated and achieving uniform heating temperature. This guarantees the heating thickness during the preheating process of multi-diameter welded pipes, effectively avoiding localized overheating or insufficient preheating, and providing a good foundation for subsequent welding processes. Furthermore, the shaping mechanism can shape the thermally conductive sand according to the arc of the weld seam of different diameter welded pipes, eliminating the need for multiple sets of clamps for different diameter welded pipes as required by clamping heating methods. This significantly saves equipment investment costs and production space, exhibiting good adaptability and economy. It is very suitable for manufacturing enterprises producing large-diameter, thick-walled welded pipes, effectively improving production efficiency and economic benefits while ensuring welding quality. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of the straight seam welded pipe preheating device in an embodiment. Figure 2 This is a schematic diagram of the operation of the straight seam welded pipe preheating device in an embodiment. Figure 3 This is a schematic diagram of the sand-dredging component structure in an embodiment; Figure 4 for Figure 3 Enlarged view of point A; Figure 5 This is a front view of the sand-dredging component in the embodiment; Figure 6 This is a schematic diagram of the heating mechanism structure in an embodiment; Figure 7 This is a schematic diagram of the heat source component structure in an embodiment; Figure 8 This is a schematic diagram of the hoisting mechanism structure in an embodiment.

[0019] Legend 1, straight seam welded pipe; 2, heating mechanism; 21, container; 22, heat source assembly; 221, gas guide channel; 222, flame nozzle; 223, igniter; 23, centrifugal vibrator; 231, fixed plate; 232, vibration motor; 233, vibration shell; 3, shaping mechanism; 31, movable gantry; 311, stand; 32, sand digging assembly; 321, hanger; 322, plough; 323, height adjusting member; 3231, adjusting motor; 3232, driving crank; 3233, connecting member; 3234, spring; 3235, arc-shaped connecting rod; 33, first lifting driving member; 34, guide rail; 35, driving wheel; 4, hoisting mechanism; 41, hoisting frame; 42, magnetic attraction assembly; 421, magnetic attraction member; 422, second lifting driving member; 423, cross frame. DETAILED DESCRIPTION

[0020] For the purpose of facilitating the understanding of the present application, the present application will be described in more detail below in conjunction with the drawings and preferred embodiments, but the scope of protection of the present application is not limited to the following specific embodiments.

[0021] It should be particularly noted that when an element is described as being "fixed to, connected to, or communicated with" another element, it can be directly fixed, connected, or communicated with the other element, or indirectly fixed, connected, or communicated with the other element through other intermediate connecting elements.

[0022] Unless otherwise defined, all the professional terms used in the following are the same as those commonly understood by those skilled in the art. The professional terms used in this paper are only for the purpose of describing the specific embodiments and are not intended to limit the scope of protection of the present application.

[0023] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present application can be purchased from the market or can be prepared by existing methods.

[0024] Embodiment: As shown in the drawings, the straight seam welded pipe preheating device of the present embodiment comprises: Figures 1 to 8 A heating mechanism 2, comprising a container 21 with an open top surface and containing heat-conducting sand, and a heat source assembly 22 for heating the heat-conducting sand; A shaping mechanism 3, comprising a sand digging assembly 32 arranged above the container 21, for creating an arc-shaped pit on the top surface of the heat-conducting sand pile, and the arc-shaped pit can be fitted with the curved surface where the weld of the straight seam welded pipe 1 is located.

[0025] ​In this embodiment, specifically, the container 21 is a rectangular box with an open top, and the heat source assembly 22 is arranged below the rectangular box to heat the heat-conducting sand in the box. The molding mechanism 3 creates an arc-shaped sand pit according to the curved surface of the weld of the straight-seam welded pipe 1, and the straight-seam welded pipe 1 is arranged in the arc-shaped pit in the box with the weld facing downward for preheating.

[0026] In this embodiment, as shown in Figure 1 and Figure 2 , the molding mechanism 3 includes a movable gantry 31 arranged above the container 21, and the sand-digging assembly 32 is arranged on the movable gantry 31 and can move up and down through the first lifting drive 33.

[0027] In this embodiment, as shown in Figure 3 , the sand-digging assembly 32 includes a hanger 321, a plough claw 322, and a height adjustment member 323. Seven plough claws 322 are arranged below the hanger 321 through the height adjustment member 323, and the plough claws 322 are arranged in the width direction of the straight-seam welded pipe 1. The hanger 321 is a horizontal frame, and the seven plough claws 322 are arranged below the hanger 321 in a staggered manner in the width direction of the straight-seam welded pipe 1. The width direction of the straight-seam welded pipe 1 is the horizontal direction perpendicular to the axis of the straight-seam welded pipe 1.

[0028] In this embodiment, the plough claw 322 includes an arc-shaped hook at the upper end connected to the height adjustment member 323, and a V-shaped plough head arranged at the lower end of the arc-shaped hook in the arc direction. The sharp part of the V-shaped plough head cuts into the heat-conducting sand to form an arc-shaped pit. The seven plough heads can form a continuous arc in the width direction of the straight-seam welded pipe 1, ensuring that the arc-shaped pit formed is more regular and accurate. In other embodiments, the number of plough claws 322 can be set according to actual conditions.

[0029] In this embodiment, as shown in Figure 5 , the height difference H between the bottom end of the plough claw 322 in the middle and the bottom end of the plough claw 322 at the most side is greater than the thickness of the pipe wall of the straight-seam welded pipe 1. The height of the plough claw 322 can be adjusted using a PLC program to meet the preset arc requirement.

[0030] In this embodiment, as shown in Figure 4 , the height adjustment member 323 includes a connecting member 3233 fixedly arranged on the hanger 321, an adjustment motor 3231 arranged on the connecting member 3233, and a drive crank 3232 connected to the adjustment motor 3231. The plough claw 322 is connected to the drive crank 3232, and the adjustment motor 3231 drives the plough claw 322 to adjust the height through the drive crank 3232.

[0031] In the embodiment, the height adjusting member 323 further comprises a spring 3234 connected to the connecting member 3233 at one end, and an arc-shaped connecting rod 3235 connected to the other end of the spring 3234, and the plough 322 is connected to the driving crank 3232 through the arc-shaped connecting rod 3235.

[0032] In the embodiment, specifically, the connecting member 3233 is divided into an arch-shaped connecting block and a long arch-shaped connecting block connected to the arch-shaped connecting block, the arch-shaped connecting block is fixedly connected to the hanger 321, and the long arch-shaped connecting block is elastically connected to the spring 3234 away from the one end of the arch-shaped connecting block. When the bottom end height of the plough 322 needs to be lowered, the adjusting motor 3231 drives the driving crank 3232 to rotate downward, the spring 3234 is elongated, and the bottom end height of the plough 322 is lowered. Conversely, the adjusting motor 3231 drives the driving crank 3232 to rotate upward, the long arch-shaped connecting block presses the spring 3234, the spring 3234 is contracted, and the plough 322 is lifted upward.

[0033] In the embodiment, as shown in Figure 2 The two sides of the container 21 are provided with guide rails 34 along the length direction of the straight-seam welded pipe 1, and the movable gantry 31 comprises four vertical columns 311, and each vertical column 311 is provided with a driving wheel 35 matched with the guide rail 34. The driving wheel 35 can be connected to the control system through PLC, and the control of the driving wheel 35 is realized through the control screen, so as to realize the movement and stop of the movable gantry 31.

[0034] In the embodiment, the driving wheel 35 is arranged at the bottom of the vertical column 311 through a wheel frame, the wheel frame is provided with a walking motor for driving the driving wheel 35 to rotate, and the wheel frame is further provided with a steering motor, and the forward rotation and reverse rotation of the steering motor can realize the back-and-forth movement along the length direction of the straight-seam welded pipe 1.

[0035] In the embodiment, as shown in Figure 7 The heat source assembly 22 comprises four air guide channels 221 arranged below the container 21 along the length direction of the straight-seam welded pipe 1, a plurality of flame nozzles 222 arranged on the air guide channels 221, and an igniter 223 arranged at one end of the air guide channels 221, and the air guide channels 221 are uniformly and spacedly arranged along the width direction of the straight-seam welded pipe 1.

[0036] In the embodiment, as shown in Figure 6 The heating mechanism 2 further comprises four centrifugal vibrators 23 arranged on the inner bottom surface of the container 21 through a fixed plate 231. The centrifugal vibrator 23 comprises a vibration motor 232, a vibration shell 233, and a centrifugal rod arranged in the vibration shell 233 and connected to the vibration motor 232 at one end, the vibration shell 233 is arranged on the inner bottom surface of the container 21 through the fixed plate 231, the vibration motor 232 is arranged outside the container 21, and the centrifugal vibrator 23 is made of high-temperature-resistant material.

[0037] In the embodiment, asFigure 8 The lifting mechanism 4 includes a set of lifting frames 41 arranged along the length direction of the straight seam welded pipe 1, and a magnetic attraction assembly 42 arranged along the length direction of the straight seam welded pipe 1. The lifting frames 41 are arranged above the container 21, and the magnetic attraction assembly 42 is arranged on the lifting frames 41 and can move horizontally along the width direction of the straight seam welded pipe 1. The magnetic attraction assembly 42 includes a magnetic attraction piece 421 and a second lifting drive 422 for driving the magnetic attraction piece 421 to lift. The lifting frames 41 are two large gantries arranged in parallel above the container 21 along the length direction of the straight seam welded pipe 1. A sliding track is arranged above the large gantries. The magnetic attraction assembly 42 further includes a cross frame 423 arranged along the length direction of the straight seam welded pipe 1. The cross frame 423 is provided with sliding blocks at both ends. The sliding blocks are slidably arranged on the sliding track through a sliding drive. The magnetic attraction piece 421 is in a strip shape and is arranged below the cross frame 423 in parallel through four second lifting drives 422. The four second lifting drives 422 synchronously drive the magnetic attraction piece 421 to move up and down.

[0038] In the embodiment, the specific implementation steps include: turning on the heat source assembly 22 to heat the heat-conducting sand, adjusting the height position of the bottom end of each plow 322 according to the diameter and thickness of the straight seam welded pipe 1, moving the movable gantry 31 along the guide track 34 to above one end of the container 21, and then lowering the plow 322 as a whole into the heat-conducting sand through the first lifting drive 33. The movable gantry 31 starts to move along the guide track 34 to the other end of the container 21, drives the plow 322 to make an arc-shaped pit, and cuts the heat-conducting sand with the sharp part of the plow head, so as to extrude the heat-conducting sand to both sides and the front, thereby realizing the formation of the arc-shaped pit. After the molding is completed, the first lifting drive 33 is adjusted to lift the plow 322 as a whole above the container 21, and the movable gantry 31 continues to move along the guide track 34 until it moves out of above the container 21. The lifting mechanism 4 is placed on one side of the container 21 through the magnetic attraction piece 421 to attract the straight seam welded pipe 1 with the weld downward, and is lifted and placed on the arc-shaped pit to start preheating. After the preheating is completed, the straight seam welded pipe 1 is lifted away, and the preheating of the next straight seam welded pipe 1 to be preheated is performed. If the model of the straight seam welded pipe 1 changes, the movable gantry 31 is first driven to return along the guide track 34, so that the plow head is reversed to plow, and part of the heated sand is brought to the arc-shaped pit. At the same time, the centrifugal vibrator 23 is turned on to complete the recovery of the heat-conducting sand through vibration. Then, the straight seam welded pipe 1 is preheated according to the above steps.

[0039] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A straight seam welded pipe preheating device characterized by comprising: The utility model relates to a kind of straight seam welded pipe sanding machine, including: Heating mechanism (2), including the container (21) of top surface open and the heat-conducting sand of stacking, and heat source assembly (22) for heating heat-conducting sand; Molding mechanism (3), including the sand excavation assembly (32) being set above the container (21), for manufacturing arc pit on the top surface of heat-conducting sand pile, and the arc pit can be attached with the curve where the weld of straight seam welded pipe (1) is located.

2. The straight seam welded pipe preheating device according to claim 1, characterized in that, The molding mechanism (3) includes a movable gantry (31) disposed above the container (21), and the sand excavation assembly (32) is movably disposed on the movable gantry (31) by a first lifting drive (33).

3. The straight seam welded pipe preheating device according to claim 2, characterized in that, The sand excavation assembly (32) includes a hanger (321), a plurality of plough claws (322) disposed below the hanger (321) by height adjustment members (323), and the plough claws (322) are arranged along the width direction of the straight seam welded pipe (1).

4. The straight seam welded pipe preheating device according to claim 3, characterized in that, The height difference H between the bottom end of the middle plough claw (322) and the bottom end of the most side plough claw (322) is greater than the thickness of the wall of the straight seam welded pipe (1).

5. The straight seam welded pipe preheating device according to claim 3, characterized in that, The height adjustment member (323) includes a connecting member (3233) fixedly connected to the hanger (321), an adjustment motor (3231) disposed on the connecting member (3233), and a drive crank (3232) connected to the adjustment motor (3231), the plough claw (322) is connected to the drive crank (3232), and the adjustment motor (3231) drives the plough claw (322) to adjust the height through the drive crank (3232).

6. The straight seam welded pipe preheating apparatus according to claim 5, characterized by The height adjustment member (323) further includes a spring (3234) connected to one end of the connecting member (3233) and an arc-shaped connecting rod (3235) connected to the other end of the spring (3234), and the plough claw (322) is connected to the drive crank (3232) through the arc-shaped connecting rod (3235).

7. The straight seam welded pipe preheating apparatus as claimed in claim 2, wherein The container (21) is provided with guide rails (34) along the length direction of the straight seam welded pipe (1) on both sides, and the movable gantry (31) includes a plurality of vertical columns (311), and the lower end of the vertical column (311) is provided with a drive wheel (35) matched with the guide rail (34).

8. The straight seam welded pipe preheating apparatus according to any one of claims 1 to 7, characterized by The heat source assembly (22) includes a plurality of gas guide channels (221) disposed below the container (21) along the length direction of the straight seam welded pipe (1), a plurality of flame nozzles (222) disposed on the gas guide channels (221), and an igniter (223) disposed on the gas guide channels (221).

9. The straight seam welded pipe preheating device according to any one of claims 1-7, characterized in that, The heating mechanism (2) further includes a plurality of centrifugal vibrators (23) disposed on the inner bottom surface of the container (21) by a fixed plate (231).

10. The straight seam welded pipe preheating apparatus according to any one of claims 1-7, characterized in that, Further comprising a hoisting mechanism (4), the hoisting mechanism (4) comprises a set of hoisting frames (41) arranged at intervals along the length direction of the straight seam welded pipe (1), and a magnetic attraction assembly (42) arranged along the length direction of the straight seam welded pipe (1), the hoisting frame (41) is arranged above the container (21), the magnetic attraction assembly (42) is arranged on the hoisting frame (41) and can move horizontally along the width direction of the straight seam welded pipe (1), the magnetic attraction assembly (42) comprises a magnetic attraction piece (421) and a second lifting driving piece (422) for driving the magnetic attraction piece (421) to lift.

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