Straight seam welded pipe preheating device

Abstract

The application discloses a straight-seam welded pipe preheating device, which comprises a heating mechanism and a shaping mechanism; the heating mechanism comprises a container with an open top surface and containing 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 can be matched with a curved surface where a weld of the straight-seam welded pipe is located. The heat-conducting sand is used for heating, and through cooperation of the container and the heat source assembly, heat can be uniformly transmitted to the weld area of the straight-seam welded pipe, the uniformity of the heating temperature is realized, the heating thickness in the preheating process of the multi-diameter welded pipe is ensured, the problems of local overheating or insufficient preheating are effectively avoided, and a good foundation is provided for subsequent welding procedures; and through the shaping mechanism, the heat-conducting sand can be shaped according to the curvature of the weld of the welded pipe with different diameters, the equipment investment cost and production space are greatly saved, and good adaptability and economy 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 joint mechanical properties. 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 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 welded pipes of various diameters, 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:

[0007] 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 heat-conducting sand stacked in the container, 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 stack, and the arc-shaped pit is capable of being fitted to the curved surface of the weld of the straight seam welded pipe.

[0008] 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.

[0009] In the straight seam welded pipe preheating device, preferably, the sand digging assembly comprises a hanger, plough claws and height adjusting members, a plurality of 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 required arc-shaped pit can be quickly dug on the top surface of the heat-conducting sand stack by simultaneous operation of the plurality of plough claws, 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 arc-shaped pit capable of being fitted to the curved surface of the weld of the straight seam welded pipe can be more accurately formed by accurately controlling the digging depth of each plough claw, the shape, size and curvature of the arc-shaped pit are ensured to meet the requirements, and the uniformity and accuracy of the preheating effect are improved.

[0010] 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.

[0011] 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.

[0012] 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.

[0013] 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 rail. The guide rail matched with the driving wheel provides a stable moving path for the movable gantry, ensures that the gantry does not deviate or shake during movement, accurately guides the moving direction of the gantry, and ensures that the sand digging assembly can accurately make an arc-shaped pit on the top surface of the heat-conducting sand pile.

[0014] 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 channel for supporting and conveying gas, and a plurality of flame nozzles are distributed thereon to ensure that the heat-conducting sand arranged above can be uniformly heated in a large area.

[0015] 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.

[0016] Preferably, the straight seam welded pipe preheating device further comprises a hoisting mechanism, the hoisting mechanism comprises a plurality 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 discharged, reducing manual operation and improving production efficiency and safety. The magnetic attraction assembly arranged therein can attract straight seam welded pipes of different lengths and diameters, enhancing its adaptability.

[0017] Compared with the prior art, the advantages of the present application are that:

[0018] The application utilizes heat-conducting sand to preheat the straight seam welded pipe through the cooperation of the container and the heat source assembly. Since the heat-conducting sand can serve as a heat preservation medium, store heat for a long time and release it slowly, the gaps between the heat-conducting sand can form a uniform heat environment, and the heat is gradually diffused to the inside of the straight seam welded pipe through heat conduction and heat convection. The heat preservation characteristic prolongs the heat action time, makes the deep layer material fully heated, realizes the uniformity of the heating temperature, ensures the heating thickness in the preheating process of the multi-diameter welded pipe, effectively avoids the problems of local overheating or insufficient preheating, and provides a good foundation for the subsequent welding process. In addition, the heat-conducting sand can be shaped through the shaping mechanism according to the arc of the weld of the welded pipe of different diameters, so it is not necessary to equip multiple sets of clamps for welded pipes of different diameters as in the clamping heating mode, which greatly saves the equipment investment cost and production space, has good adaptability and economy, and is very suitable for production and manufacturing enterprises of large-diameter thick-walled welded pipes. Under the premise of ensuring the welding quality, the production efficiency and economic benefits are effectively improved. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0020] Figure 1 It is a schematic diagram of the overall structure of the straight seam welded pipe preheating device of the embodiment.

[0021] Figure 2 It is a working schematic diagram of the straight seam welded pipe preheating device of the embodiment.

[0022] Figure 3 It is a schematic diagram of the sand digging assembly structure of the embodiment.

[0023] Figure 4 It is an enlarged view of A of Figure 3

[0024] Figure 5 It is a front view of the sand digging assembly of the embodiment.

[0025] Figure 6 It is a schematic diagram of the heating mechanism structure of the embodiment.

[0026] Figure 7 It is a schematic diagram of the heat source assembly structure of the embodiment.

[0027] Figure 8 It is a schematic diagram of the hoisting mechanism structure of the embodiment.

[0028] LEGEND

[0029] ​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, plow; 323, height adjusting piece; 3231, adjusting motor; 3232, driving crank; 3233, connecting piece; 3234, spring; 3235, arc-shaped connecting rod; 33, first lifting driving piece; 34, guide rail; 35, driving wheel; 4, hoisting mechanism; 41, hoisting frame; 42, magnetic attraction assembly; 421, magnetic attraction piece; 422, second lifting driving piece; 423, cross frame. DETAILED DESCRIPTION

[0030] For the purpose of promoting the understanding of the present application, the present application will be more fully described by way of example with reference to the accompanying drawings, in which:

[0031] It should be noted that when an element is described as being "fixed to", "connected to", "coupled to" or "in communication with" another element, it can be directly fixed, connected, coupled or in communication with the other element, or it can be indirectly fixed, connected, coupled or in communication with the other element through other intermediate connecting elements.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The materials used to describe the present application should not be considered limiting. Instead, the scope of the application is to be determined by the appended claims and their equivalents.

[0033] Unless otherwise specified, the various materials, reagents, instruments and equipment used in the present application can be purchased on the market or can be prepared by existing methods.

[0034] Embodiment:

[0035] As shown in the drawings, the straight seam welded pipe preheating device of the present embodiment comprises: Figures 1 to 8

[0036] The heating mechanism 2 comprises 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.

[0037] The shaping mechanism 3 comprises 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 is capable of conforming to the curved surface where the weld of the straight seam welded pipe 1 is located.

[0038] ​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.

[0039] 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.

[0040] In this embodiment, as shown in Figure 3 , the sand digging assembly 32 includes a hanger 321, a plough claw 322, and a height adjusting member 323. Seven plough claws 322 are arranged below the hanger 321 through the height adjusting 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.

[0041] In this embodiment, the plough claw 322 includes an arc-shaped hook connected to the height adjusting member 323 at the upper end, 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.

[0042] 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.

[0043] In this embodiment, as shown in Figure 4 , the height adjusting member 323 includes a connecting member 3233 fixedly arranged on the hanger 321, an adjusting motor 3231 arranged on the connecting member 3233, and a drive crank 3232 connected to the adjusting motor 3231. The plough claw 322 is connected to the drive crank 3232, and the adjusting motor 3231 drives the plough claw 322 to adjust the height through the drive crank 3232.

[0044] 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.

[0045] 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.

[0046] In the embodiment, as shown in Figure 2 the container 21 is 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.

[0047] 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 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.

[0048] 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.

[0049] 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 fixing plates 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 fixing plate 231, the vibration motor 232 is arranged outside the container 21, and the centrifugal vibrator 23 is made of high-temperature-resistant material.

[0050] In the embodiment, as shown inFigure 8 As shown, it also includes a hoisting mechanism 4, which includes a set of hoisting frames 41 spaced apart along the length of the straight seam welded pipe 1, and a magnetic suction assembly 42 arranged along the length of the straight seam welded pipe 1. The hoisting frames 41 are straddling the container 21, and the magnetic suction assembly 42 is arranged on the hoisting frames 41 and can be moved horizontally along the width of the straight seam welded pipe 1. The magnetic suction assembly 42 includes a magnetic suction element 421 and a second lifting drive element 422 for driving the magnetic suction element 421 to rise and fall. The hoisting frame 41 consists of two large gantry frames, which are parallel to each other and span above the container 21 along the length of the straight seam welded pipe 1. A sliding track is provided above the large gantry frames. The magnetic suction assembly 42 also includes a horizontal frame 423 along the length of the straight seam welded pipe 1. The horizontal frame 423 has sliders at both ends. The sliders are slidably mounted on the sliding track by a sliding drive. The magnetic suction component 421 is long and narrow. It is parallel to the horizontal frame 423 by four second lifting drive components 422. The four second lifting drive components 422 synchronously drive the magnetic suction component 421 to move up and down.

[0051] In this embodiment, the specific implementation steps include: turning on the heat source component 22 to heat the heat-conducting sand; adjusting the bottom height of each plowshare 322 according to the diameter and thickness of the straight seam welded pipe 1; moving the movable gantry frame 31 along the guide rail 34 to above one end of the container 21; then lowering the plowshare 322 as a whole into the heat-conducting sand pile via the first lifting drive component 33; moving the movable gantry frame 31 along the guide rail 34 to the other end of the container 21, driving the plowshare 322 to create an arc-shaped pit; the tip of the plowshare cutting into the heat-conducting sand, squeezing the heat-conducting sand to both sides and the front to form the arc-shaped pit; and adjusting the first lifting drive component 33 to lower the plowshare 322 as a whole. The pipe rises above container 21 and continues to move along guide rail 34 until it is removed from above container 21. The hoisting mechanism 4 is attached to one side of container 21 by magnetic suction 421, with the weld seam facing down, and is hoisted onto the arc pit to start preheating. After preheating, the straight seam welded pipe 1 is hoisted away, and the next straight seam welded pipe 1 to be preheated is preheated. If the model of the straight seam welded pipe 1 changes, the mobile gantry 31 is first driven to move back along guide rail 34, so that the plow head performs reverse plowing and brings some heated sand to the arc pit. At the same time, the centrifugal vibrator 23 is turned on to restore the heat-conducting sand through vibration. Then, the straight seam welded pipe 1 is preheated according to the above steps.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A preheating device for straight seam welded pipes, characterized in that, include: The heating mechanism (2) includes a container (21) with an open top and filled with heat-conducting sand, and a heat source assembly (22) for heating the heat-conducting sand. The shaping mechanism (3) includes a sand-digging component (32) located 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 fit into the curved surface where the weld of the straight seam welded pipe (1) is located.

2. The straight seam welded pipe preheating device according to claim 1, characterized in that, The shaping mechanism (3) includes a movable gantry (31) spanning above the container (21), and the sand dredging component (32) is mounted on the movable gantry (31) and can be moved up and down via a first lifting drive component (33).

3. The straight seam welded pipe preheating device according to claim 2, characterized in that, The sand-dredging assembly (32) includes a hanger (321), plow claws (322) and a height adjustment component (323). Multiple plow claws (322) are respectively located below the hanger (321) through the height adjustment component (323). The plow 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 plow claw (322) and the bottom end of the outermost plow 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 component (323) includes a connector (3233) fixed on the hanger (321), an adjustment motor (3231) provided on the connector (3233), and a drive crank (3232) connected to the adjustment motor (3231). The plow claw (322) is connected to the drive crank (3232), and the adjustment motor (3231) drives the plow claw (322) to adjust the height through the drive crank (3232).

6. The straight seam welded pipe preheating device according to claim 5, characterized in that, The height adjustment component (323) also includes a spring (3234) with one end connected to the connector (3233) and an arc-shaped connecting rod (3235) connected to the other end of the spring (3234). The plow pawl (322) is connected to the drive crank (3232) through the arc-shaped connecting rod (3235).

7. The straight seam welded pipe preheating device according to claim 2, characterized in that, The container (21) has guide rails (34) on both sides along the length of the straight seam welded pipe (1). The mobile gantry (31) includes multiple columns (311), and the lower end of the column (311) is provided with a drive wheel (35) that cooperates with the guide rail (34).

8. The straight seam welded pipe preheating device according to any one of claims 1-7, characterized in that, The heat source assembly (22) includes a plurality of gas 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 gas guide channels (221), and an igniter (223) arranged on the gas guide channels (221).

9. The preheating device for straight seam welded pipes according to any one of claims 1-7, characterized in that, The heating mechanism (2) also includes a plurality of centrifugal vibrators (23), which are mounted on the bottom surface of the container (21) via a fixed plate (231).

10. The preheating device for straight seam welded pipes according to any one of claims 1-7, characterized in that, It also includes a hoisting mechanism (4), which includes a set of hoisting frames (41) spaced apart along the length of the straight seam welded pipe (1) and a magnetic suction assembly (42) arranged along the length of the straight seam welded pipe (1). The hoisting frame (41) spans above the container (21), and the magnetic suction assembly (42) is horizontally movable along the width of the straight seam welded pipe (1) and is mounted on the hoisting frame (41). The magnetic suction assembly (42) includes a magnetic suction element (421) and a second lifting drive element (422) for driving the magnetic suction element (421) to rise and fall.

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