Welding device for fracture of fan impeller of hot blast stove

Abstract

The welding device comprises a horizontal rotating support, the horizontal rotating support comprises a vertically-arranged door-shaped frame and triangular supports arranged at the two ends of the front side of the door-shaped frame respectively, a center hole is formed in the center of the upper portion of the door-shaped frame, and the left side of the door-shaped frame is provided with a hole. Rotating shaft locking mechanisms are arranged on the two sides, and a horizontal rotating shaft is rotationally arranged in the center hole in a penetrating mode through a shaft sleeve; wherein the front end of the horizontal rotating shaft is used for being connected with a central shaft hole of the fan impeller, the fan impeller is driven to rotate through the horizontal rotating shaft, and the horizontal rotating shaft is locked through the rotating shaft locking mechanism. By applying the device, the problem of off-line local welding repair of the fan impeller can be effectively solved.

Description

Technical Field

[0001] This utility model belongs to the field of welding technology, specifically relating to a welding device for the fracture of a hot blast furnace fan impeller. Background Technology

[0002] The furnace blower is a key component of a bell-type furnace system, primarily used to circulate gas within the furnace, ensuring uniform temperature distribution and improving heat treatment efficiency. The bell-type furnace blower mainly consists of a casing, impeller, and motor. The impeller is the core component of the blower. Figure 1 and Figure 2 As shown, the fan impeller 1 includes a circular back plate 11 and an annular front frame 12 arranged opposite each other. A rotating ring 13 is disposed through the center of the circular back plate 11, and a central shaft hole 14 is opened in the center of the rotating ring 13. Multiple horizontal blades 16 are evenly spaced and welded between the circular back plate 11 and the annular front frame 12. A vertical blade 15 is welded to the middle of adjacent horizontal blades 16. The central shaft hole 14 of the impeller is used to connect to the output end of the motor, and the motor drives the impeller to rotate. When the motor starts and drives the impeller to rotate, the pressure and velocity of the gas increase during this process, forming a negative pressure, which allows outside air to enter the fan through the air inlet. Subsequently, under the acceleration of the impeller, the gas is discharged from the air outlet at a high speed, forming an airflow. During the operation of the fan, due to overload operation, vibration, high temperature, design defects, etc., the impeller often cracks directly during operation. Figure 7 The impeller photos shown show vertical blade breakage or cracks, forcing a production shutdown for maintenance. To resume production as soon as possible, on-site welding repair of the cracked impeller of the bell-type furnace blower is required. The reasons are: (1) If not handled in time, the expansion of the local impeller crack may lead to a major equipment accident. (2) If the entire impeller is replaced, it will not only waste a lot of costs, but also have a long procurement cycle that affects the production rhythm. (3) The working conditions are complex and online repair is difficult. If offline on-site welding repair is considered, there are no toolings for supporting and rotating the impeller, making welding repair inconvenient. In addition, since the hot air furnace blower impeller is made of high-temperature alloy material and is heat-treated by integral welding, such materials also have the following problems when repairing local welding: welding defects are easy to occur. Due to local repair welding, uneven thermal expansion and contraction may occur, and hot cracks, cold cracks, welding deformation, etc. may occur. Utility Model Content

[0003] In view of the technical problems existing in the background art, this utility model provides a welding device for the fracture of hot blast stove fan impeller, which effectively solves the problem of offline partial welding repair of fan impeller.

[0004] The technical solution to the technical problem solved by this utility model is as follows:

[0005] According to one aspect of this utility model, a welding device for the fracture of a hot blast stove fan impeller is provided. The device includes a horizontal rotating support, which comprises a vertically arranged portal frame and triangular supports respectively disposed at both ends of the front side of the portal frame. A central hole is provided at the center of the upper part of the portal frame, and rotating shaft locking mechanisms are provided on both sides. A horizontal rotating shaft is rotatably disposed within the central hole through a bushing. The front end of the horizontal rotating shaft is used to connect to the central shaft hole of the fan impeller, thereby driving the fan impeller to rotate. The horizontal rotating shaft is locked by the rotating shaft locking mechanisms.

[0006] Furthermore, the pivot locking mechanism includes two first fixed baffles and two second fixed baffles that are respectively spaced apart on the upper part of the portal frame and symmetrical about the central hole. The first fixed baffles and the two second fixed baffles are respectively provided with a first locking hole and a second locking hole at their center. Locking screws are correspondingly threaded in the two first locking holes, and locking bearing fixtures are correspondingly provided in the two second locking holes. The locking bearing fixtures include push rods that are slidably provided in the second locking holes, and bearing units are respectively provided at the corresponding ends of the two push rods.

[0007] Furthermore, a handle is provided at the outer end of the horizontal rotating shaft.

[0008] Furthermore, a connecting plate is fixedly provided at the bottom end of the portal frame.

[0009] Furthermore, the portal frame and triangular bracket are manufactured by cutting and welding steel plates, the bushing is manufactured by cutting steel pipes, and the horizontal rotating shaft is manufactured by cutting round bars.

[0010] Furthermore, the first and second fixed baffles are made by cutting steel plates, the locking bearing fixture is made by cutting and welding steel pipes and round bars, and the locking screw is made by cutting round bars.

[0011] According to another aspect of this utility model, a welding process for repairing a broken hot blast stove fan impeller is provided. The fan impeller includes a circular back plate and an annular front frame arranged opposite each other. A rotating ring is disposed through the center of the circular back plate, and a central shaft hole is opened in the center of the rotating ring. Multiple horizontal blades are welded evenly spaced between the circular back plate and the annular front frame, and vertical blades are welded to the middle of adjacent horizontal blades. After long-term operation of the fan impeller, several vertical blades break. The vertical blades are repaired by welding using the welding device for repairing broken hot blast stove fan impellers described above. The welding process steps are as follows:

[0012] S1. Pre-welding preparation:

[0013] 1.1) Welding equipment: A DC welding machine combining digitally controlled inverter-type manual arc welding and argon arc welding;

[0014] 1.2) Welding material: 309LG stainless steel welding wire;

[0015] 1.3) Auxiliary facilities: angle grinder, file, hammer, chisel, face mask, template, thermometer, magnifying glass, insulation cotton;

[0016] 1.4) Welding material: SUS316;

[0017] 1.5) Pre-welding overlay requirements: The welding area and welding rod must be free of oil, oxide layer and moisture, and must expose the metallic luster;

[0018] 1.6) Welding position: Flat angle butt joint with K-type bevel;

[0019] 1.7) Welding requirements: All weld layers must be free of any welding defects and fused to the base material;

[0020] 1.8) Develop welding parameters based on welding equipment, welding materials, workpiece materials, and welding requirements;

[0021] S2, Welding implementation;

[0022] 2.1) Connect the fan impeller to the end of the horizontal shaft of the welding device through the central shaft hole of the rotating ring, and rotate the vertical blade breakage position of the fan impeller to the horizontal welding position through the horizontal shaft;

[0023] 2.2) Use an angle grinder to clean and bevel both ends of the vertical blade, and make it form a K-shaped bevel with the two adjacent horizontal blades at the fracture location. Let the flat angle welding positions on both sides of the K-shaped bevel at one end of the vertical blade be A and B respectively, and the flat angle welding positions on both sides of the K-shaped bevel at the other end be C and D respectively. Clean the oil stains within 100mm on both sides of the K-shaped bevel, and perform 100% dye penetrant testing to ensure that there are no surface defects.

[0024] 2.3) Using a welding machine and stainless steel 309LG welding wire, perform the root pass, filler pass, and cap pass welding for each flat corner welding position. The root pass is done symmetrically using manual argon arc welding with a 1.7%–2.2% thorium tungsten electrode (TTI), Ф2.5mm. The welding sequence for each flat corner welding position is as follows: positions A and C are welded symmetrically first. After cleaning the root and visually inspecting or using a 10x magnifying glass to confirm the weld is free of defects, positions B and D are then welded symmetrically. During welding, ensure the K-groove root is fully penetrated. The filler wire should not be directly immersed in the molten pool; it should be positioned in front of the tungsten electrode and fed in while melting to avoid damaging the argon gas shielding. Simultaneously, carefully observe the melting at the groove edge to avoid undercut and incomplete fusion defects. Each weld bead should be relatively thin. For welds with a thickness of 2mm, the continuous welding length should be controlled at around 80mm. Pause briefly after each weld reaches this length, cover the weld area with a damp cloth, and continuously pour water onto the cloth as the welding temperature rises. Maintain the temperature around the weld and between layers below 60℃, and use a temperature gun to measure the temperature simultaneously. After all the bottom layers are symmetrically welded, use a manual angle grinder to grind the surface welds. After visual inspection or observation with a 10x magnifying glass to ensure no welding defects, proceed with the same method for the fillet and cap coat layers. When welding the cap coat, the fillet weld cap coat must not exceed the designed weld leg size of the base material, and there should be no undercut between the weld toes and the base material on both sides. The weld should have a smooth transition. After all welding is completed, cover the entire weld with a damp cloth and allow it to cool to room temperature.

[0025] 2.4) After welding, the weld is ground and inspected by PT to ensure that there are no exposed pores, slag inclusions, sharp grooves with a depth greater than 0.2mm, or other surface defects. After MT internal inspection finds no welding defects, it is put into use.

[0026] Furthermore, the welding equipment is a DC welding machine of model HT400D or HT500D, which is a digitally controlled inverter type that combines manual arc welding and argon arc welding.

[0027] Furthermore, when welding the root pass, use Φ2.0mm 309LG welding wire, with a welding current of 70-90A, an arc voltage of 19±1V, and a welding speed of 15±1cm / min; when welding the filler and cover passes, use Φ3.0mm 309LG welding wire, with a welding current of 80-100A, an arc voltage of 23±1V, and a welding speed of 17±1cm / min.

[0028] Compared with the prior art, the welding device for the fracture of the hot blast stove fan impeller described in this utility model has the following advantages:

[0029] (1) This utility model adopts a digitally controlled inverter manual argon arc welding machine, low-grade stainless steel welding materials, symmetrical flat corner welding, and achieves on-site local control of welding temperature less than 60℃, which can effectively eliminate stress and deformation to meet the welding process.

[0030] (2) The welding fixture designed in this utility model effectively ensures that the fan impeller is placed horizontally when offline, and can be adjusted 360 degrees to meet all welding specifications.

[0031] (3) The welding device and process described in this utility model not only have low investment costs, convenient on-site operation and maintenance, and short repair time, but also the metallurgically bonded weld layer of the fan impeller after partial welding repair can meet the requirements for periodic use. Attached Figure Description

[0032] Figure 1 and Figure 2 This is a schematic diagram of the wind turbine impeller from different perspectives in this utility model;

[0033] Figure 3 This is a schematic diagram of the welding device in use according to this utility model;

[0034] Figure 4 for Figure 3 An explosion diagram;

[0035] Figure 5 and Figure 6 These are schematic diagrams of the horizontal rotating bracket in this utility model from different perspectives;

[0036] Figure 7 These are on-site photos showing vertical blades of an impeller fan breaking or cracking after long-term operation.

[0037] In the diagram: 1. Fan impeller; 11. Circular back plate; 12. Annular front frame; 13. Rotating ring; 14. Central shaft hole; 15. Vertical blade; 16. Horizontal blade; 2. Horizontal rotating bracket; 21. First fixed baffle; 211. First locking hole; 22. Second fixed baffle; 221. Second locking hole; 23. Central hole; 24. Triangular bracket; 25. Portal frame; 26. Connecting plate; 3. Bushing; 4. Locking bearing fixture; 41. Top rod; 42. Bearing unit; 5. Locking screw; 6. Horizontal rotating shaft; 61. Handle. Detailed Implementation

[0038] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art to which this disclosure pertains. The terms "upper," "lower," "left," "right," "front," and "back" used in the present patent application specification and claims are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship also changes accordingly. Words such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Any aspects not detailed in the present utility model are well-known technologies to those skilled in the art.

[0039] Example 1:

[0040] like Figure 1-6 As shown, this utility model discloses a welding device for the broken impeller of a hot blast stove. It is used for supporting and rotating the impeller during partial welding repair. The impeller 1 includes a circular back plate 11 and an annular front frame 12 arranged opposite to each other. A rotating ring 13 is provided through the center of the circular back plate 11. A central shaft hole 14 is provided in the center of the rotating ring 13. Multiple horizontal blades 16 are welded evenly between the circular back plate 11 and the annular front frame 12. A vertical blade 15 is welded in the middle of adjacent horizontal blades 16. The welding device includes a horizontal rotating support 2, which includes a vertically arranged portal frame 25 and triangular supports 24 respectively arranged at both ends of the front side of the portal frame 25. A central hole 23 is opened at the center of the upper part of the portal frame 25, and a rotating shaft locking mechanism is arranged on both sides. A horizontal rotating shaft 6 is rotatably arranged through the central hole 23 via a bushing 3. The front end of the horizontal rotating shaft 6 is used to connect with the central shaft hole 14 of the fan impeller 1. The fan impeller 1 is driven to rotate by the horizontal rotating shaft 6, and the horizontal rotating shaft 6 is locked by the rotating shaft locking mechanism. The pivot locking mechanism includes two first fixed baffles 21 and two second fixed baffles 22, which are respectively spaced apart on the upper part of the portal frame 25 and symmetrical about the central hole 23. The first fixed baffles 21 and the two second fixed baffles 22 are respectively provided with a first locking hole 211 and a second locking hole 221 at their centers. Locking screws 5 are correspondingly threaded in the two first locking holes 211. Locking bearing fixtures 4 are correspondingly provided in the two second locking holes 221. The locking bearing fixtures 4 include push rods 41 that are slidably provided in the second locking holes 221. Bearing units 42 are respectively provided at the corresponding ends of the two push rods 41.

[0041] In application, after connecting the fan impeller 1 to the horizontal rotating shaft 6 through the central shaft hole 14, the fan impeller 1 can be rotated by rotating the horizontal rotating shaft 6. When it rotates to the welding repair position, the locking screws 5 on both sides of the rotating gantry frame 25 are rotated. The front end of the locking screw 5 pushes the top rod 41 forward, thereby driving the bearing unit 42 to lock the horizontal rotating shaft 6, and thus locking the position of the fan impeller 1.

[0042] To facilitate the rotation of the fan impeller mounted at its end via the horizontal shaft 6, in a preferred embodiment, a handle 61 is provided at the outer end of the horizontal shaft 6.

[0043] To improve the stability of the portal frame 25, as a preferred embodiment, a connecting plate 26 is fixedly provided at the bottom of the portal frame 25.

[0044] To improve the stability of the entire welding device, the gantry frame 25 and the triangular support 24 are made by cutting and welding 50mm steel plates, the bushing 3 is made by cutting and machining 200mm diameter steel pipes, and the horizontal rotating shaft 6 is made by cutting and machining 160mm diameter round bars. The first fixed baffle 21 and the second fixed baffle 22 are made by cutting 50mm steel plates, the locking bearing fixture 4 is made by cutting and welding 200mm diameter steel pipes and 60mm diameter round bars, and the locking screw 5 is made by cutting and machining 60mm diameter round bars.

[0045] Example 2:

[0046] This utility model provides a welding process for the fracture of a hot blast stove fan impeller. The fan impeller 1 includes a circular back plate 11 and an annular front frame 12 arranged opposite to each other. A rotating ring 13 is disposed through the center of the circular back plate 11, and a central shaft hole 14 is opened in the center of the rotating ring 13. A plurality of horizontal blades 16 are welded evenly between the circular back plate 11 and the annular front frame 12. A vertical blade 15 is welded to the middle of an adjacent horizontal blade 16. After long-term operation of the fan impeller 1, several vertical blades 15 break. The vertical blades 15 are repaired by welding using the welding device for the fracture of the hot blast stove fan impeller in Embodiment 1. The welding process steps are as follows:

[0047] S1. Pre-welding preparation:

[0048] 1.1 Welding equipment: Model HT400D or HT500D digital control inverter type DC welding machine for combined manual arc welding and argon arc welding;

[0049] 1.2 Welding materials: 309LG stainless steel welding wire, Φ2.0mm and Φ3.0mm;

[0050] 1.3 Auxiliary facilities: angle grinder, file, hammer, chisel, face mask, template, thermometer, magnifying glass, insulation cotton;

[0051] 1.4 Welding material: SUS316;

[0052] 1.5 Requirements for pre-welding surfacing: The welding area and welding rod must be free of oil, oxide layer and moisture, and must expose the metallic luster;

[0053] 1.6 Welding position: Flat angle butt joint with K-type bevel;

[0054] 1.7 Welding Requirements: All welded layers must be free of any welding defects and fused to the base material;

[0055] 1.8. Develop welding parameters based on welding equipment, welding materials, workpiece materials, and welding requirements;

[0056] Welding process parameters

[0057] (Welding electrode) type weld layer (Welding wire) diameter / mm Welding current A Arc voltage / V <![CDATA[Welding speed / (cm`min -1 )]]> 309LG Start from the bottom Φ2.0mm 70-90 19±1 15±1 309LG Filler and cover layer Φ3.0mm 80-100 23±1 17±1

[0058] S2, Welding implementation;

[0059] Welding process route: First, cut, weld, reinforce, and fabricate the welding device and install the impeller to be repaired -- adjust and rotate the impeller to a horizontal position -- clean and prepare the bevel with an angle grinder -- perform symmetrical welding of the bottom layer -- water cooling on both sides of the weld -- control the temperature of the weld and heat-affected zone to be less than 60℃ after welding -- confirm defects -- perform symmetrical filling and capping welding -- control the interpass temperature -- confirm defects -- perform rough and fine machining of the surface by hand -- inspection and acceptance -- delivery for use. Specifically:

[0060] 2.1 Connect the fan impeller 1 to the end of the horizontal rotating shaft 6 of the welding device through the central shaft hole 14 of the rotating ring 13, and rotate the vertical blade 15 of the fan impeller 1 to the horizontal welding position through the horizontal rotating shaft 6 to facilitate operation by the operator;

[0061] 2.2 To ensure good fusion and formation of the weld with the base material, an angle grinder was used to clean and bevel both ends of the vertical blade 15, forming a K-shaped bevel with the two adjacent horizontal blades 16 at the fracture location. The flat angle welding positions on both sides of the K-shaped bevel at one end of the vertical blade 15 are A and B, respectively, and the flat angle welding positions on both sides of the K-shaped bevel at the other end are C and D, respectively. Oil stains within 100mm on both sides of the K-shaped bevel were cleaned, and 100% dye penetrant testing was performed to ensure no surface defects.

[0062] 2.3. Using a welding machine and stainless steel 309LG welding wire, perform the root pass, filler pass, and cap pass welding for each flat corner welding position. To ensure a stable welding arc, the root pass is performed using manual argon arc welding symmetrically. The electrode used is a 1.7%–2.2% (Wh-15) thorium tungsten electrode, Ф2.5mm. The welding sequence for each flat corner welding position is as follows: positions A and C are welded symmetrically first. After cleaning the root and visually inspecting or using a 10x magnifying glass to confirm the weld is free of defects, positions B and D are welded symmetrically. During welding, ensure the root of the K-groove is fully penetrated. The filler wire should not be directly immersed in the molten pool to avoid damaging the argon gas protection. The filler wire should be positioned in front of the tungsten electrode, melting and feeding simultaneously. Observe the melting of the groove edge to avoid undercut and incomplete fusion defects. The thickness of each weld bead should not exceed 2mm, and the continuous welding length should be controlled at approximately 80mm. After reaching this welding length, slightly... A pause is needed because continuous welding can cause excessively high temperatures in the weld and heat-affected zone, leading to various welding defects such as stress corrosion of stainless steel. Therefore, a damp cloth is used to cover the area around the weld, and water is continuously poured onto the cloth as the welding temperature rises to control the temperature around the weld and between layers below 60°C. A temperature gun is used to measure the temperature simultaneously to further reduce stress and deformation during the welding process. After all the bottom layers are symmetrically welded, the surface welds are ground using a manual angle grinder. After visual inspection or observation with a 10x magnifying glass to ensure there are no welding defects, the same method is used to weld the fillet layer and the capping layer. When welding the capping layer, the fillet weld capping layer must not be higher than the designed weld leg size of the base material, and there should be no undercut between the weld toes on both sides and the base material. The weld should have a smooth transition to prevent cracks in the fan impeller during long-term use, which could cause the stainless steel plate to tear again. After all welding is completed, the entire weld is covered with a damp cloth to cool to room temperature.

[0063] 2.4 After welding, the weld is ground and inspected by PT to ensure that there are no exposed pores, slag inclusions, sharp grooves with a depth greater than 0.2mm, or other surface defects. After MT internal inspection confirms that there are no welding defects, a pre-made conforming template is used for comparison. The impeller is then restored to use and put into service. After a period of use, the impeller achieves the desired mechanical performance.

Claims

1. A welding device for the fracture of a hot blast stove fan impeller, characterized in that, It includes a horizontal rotating bracket (2), which includes a vertically arranged portal frame (25) and triangular brackets (24) respectively arranged at both ends of the front side of the portal frame (25). A central hole (23) is provided at the center of the upper part of the portal frame (25), and a rotating shaft locking mechanism is provided on both sides. A horizontal rotating shaft (6) is rotatably arranged through a bushing (3) in the central hole (23). The front end of the horizontal rotating shaft (6) is used to connect with the central shaft hole (14) of the fan impeller (1). The fan impeller (1) is driven to rotate by the horizontal rotating shaft (6), and the horizontal rotating shaft (6) is locked by the rotating shaft locking mechanism.

2. The welding device for the fracture of a hot blast stove fan impeller according to claim 1, characterized in that, The rotating shaft locking mechanism includes two first fixed baffles (21) and two second fixed baffles (22) that are respectively spaced apart on the upper part of the portal frame (25) and symmetrical about the central hole (23). The first fixed baffles (211) and the two second fixed baffles (22) are respectively provided with a first locking hole (211) and a second locking hole (221). Locking screws (5) are correspondingly threaded in the two first locking holes (211). Locking bearing fixtures (4) are correspondingly provided in the two second locking holes (221). The locking bearing fixtures (4) include a push rod (41) that is slidably provided in the second locking hole (221). Bearing units (42) are respectively provided at the corresponding ends of the two push rods (41).

3. The welding device for the fracture of a hot blast stove fan impeller according to claim 1, characterized in that, A handle (61) is provided at the outer end of the horizontal rotating shaft (6).

4. The welding device for the fracture of a hot blast stove fan impeller according to claim 1, characterized in that, A connecting plate (26) is fixedly installed at the bottom of the gantry frame (25).

5. The welding device for the fracture of a hot blast stove fan impeller according to claim 1, characterized in that, The portal frame (25) and the triangular bracket (24) are made by cutting and welding steel plates, the bushing (3) is made by cutting steel pipes, and the horizontal rotating shaft (6) is made by cutting round bars.

6. The welding device for the fracture of a hot blast stove fan impeller according to claim 2, characterized in that, The first fixed baffle (21) and the second fixed baffle (22) are made by cutting steel plates. The locking bearing fixture (4) is made by cutting and welding steel pipes and round bars. The locking screw (5) is made by cutting round bars.

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