A method for repairing water leakage inside the steel beam water jacket furnace from outside the furnace.

Abstract

The present invention relates to a method for repairing water leakage inside a steel beam water jacket furnace outside a furnace, and belongs to the technical field of smelting furnaces and kilns. The inner layer of the water jacket is located on one side of the furnace as side a, and the other side outside the furnace as side b. The inner layer water leakage point is found through the furnace front observation port and the water jacket drain port, the corresponding water jacket position number is locked, the corresponding water leakage area is located and cut on the outer layer of the water jacket to expose the inner layer water leakage point in the water jacket cavity; the leakage point and surrounding foreign matter are removed, and the leakage point is enlarged to an elliptical hole, and three layers of welding are adopted, namely, a side steel plate rectangular block welding and b side steel plate rectangular block welding and hole inner wall welding rod welding; the outer layer of the water jacket is cut and removed to open a V-shaped groove, and the welded part of the water jacket is treated in the same way before welding; the present invention does not enter the furnace for welding, but locates the leakage point, cuts the outer layer steel plate of the water jacket, and welds the leakage point in three layers in the water jacket cavity, which is simple to operate, short in time, low in risk, and increases the service life of the repaired steel beam water jacket.

Description

Technical Field

[0001] The invention relates to the technical field of smelting furnaces, and in particular to a method for repairing water leakage inside a steel beam water jacket furnace outside the furnace. Background Art

[0002] The side-blown furnace is composed of multiple layers of water jackets of different materials and shapes, among which the steel beam water jacket is a supporting water jacket, which is a rectangular water jacket with a square cross-section. The inner layer of the water jacket is located in the furnace to protect the slag from cooling, and the outer layer of the water jacket is located outside the furnace to protect it. In order to prevent the continuous high temperature in the furnace from eroding the inner layer, the steel beam water jacket is designed with a steel water jacket. The water jacket will have varying degrees of thermal corrosion after long-term use, and water leakage may occur in severe cases. Once the water jacket leaks from the inside, there will be huge safety hazards. The leakage must be stopped in time to prevent a large amount of water and hot lead slag from causing an explosion. However, due to its large size and the role of supporting the upper molten steel jacket, it is difficult to remove and weld. The commonly used repair method in the industry is in-furnace welding or removal and replacement. When the water jacket is inspected, the feeding and air inlet are stopped and the cooling circulating water is continuously circulated to maintain the insulation state. In-furnace welding requires shutdown for cooling. After the furnace is ventilated and tested, scaffolding and top protection are built inside the furnace. The welder wears protective equipment and performs welding on the leaking part of the inner layer of the water jacket.

[0003] Furnace repair welding has the following disadvantages:

[0004] 1) The process is complicated and takes a long time. If you want to perform repair welding in the furnace, you first need to remove a water jacket in the middle where there is no water pipe blocking it as an inlet and outlet; secondly, force the furnace to blow air and test the gas in the furnace. Only after passing the test can you enter the receiving space for operation. During this period, uninterrupted testing is required. If harmful gases exceed the standard, you need to evacuate in time; thirdly, due to the small inlet and outlet channels and the cramped working environment, the process of erecting and dismantling scaffolding and top protection after operation is slow; finally, welders need to wear protective clothing to work in a limited space, the working environment is harsh, and the efficiency is low. Problems in the above links will cause interruptions in operations and prolonged downtime. It takes a long time to disassemble the water jacket, erect and dismantle the scaffolding and protection. Therefore, the overall maintenance time is long and uncontrollable, normally requiring 24-48 hours, and the removal and replacement time is longer, and the cost is higher.

[0005] 2) The risk is relatively high. The top of the steel beam water jacket is an ascending flue. During production, soot and slag will adhere to the flue surface. These materials are in block form and have a maximum drop of 30 meters from the repair welding area. There is a certain probability of falling during the operation, which may cause risks to personnel. At the same time, the operation in the furnace belongs to the confined space operation. Because a layer of anthracite will be added to the furnace for insulation before the furnace is shut down, there is a certain probability of causing CO poisoning. There is also the risk of falling and CO poisoning during removal and replacement.

[0006] How to implement online rapid repair of molten steel jacket while avoiding the above two difficulties is the problem to be solved by the present invention. Summary of the invention

[0007] The purpose of the present invention is to provide a method for repairing water leakage inside the water jacket of a steel beam outside the furnace. The method does not enter the furnace for welding, but instead finds the leakage point position of the inner layer of the water jacket of the steel beam, locates the leakage point position, cuts the steel plate at the corresponding position of the outer layer of the water jacket, and welds the leakage point in the water jacket cavity, so as to solve the problems of traditional repair technology that is difficult, risky, time-consuming and has complicated procedures.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A method for repairing water leakage inside a steel beam water jacket furnace outside the furnace, comprising:

[0010] (1) Leak point location

[0011] The steel beam water jacket is a two-layer structure with a reinforcing rib plate in the middle. The inner layer is the layer close to the furnace. The side of the inner layer located in the furnace is side a, and the side located outside the furnace is side b. When the inner layer leaks, the side-blowing furnace stops feeding, turns off oxygen, closes the air inlet and enters the insulation state to ensure the normal operation of the circulating water. Through the observation hole in front of the furnace and the water jacket drain outlet, use a strong flashlight to illuminate and find the corrosion and leakage points of the inner layer of the steel beam water jacket. According to the up, down, left and right distances, lock the corresponding leaking water jacket position number of the inner layer. Take the number of water jacket plates with the closest observation hole and drain outlet as a reference, compare the size and position of the outer edge of the steel beam water jacket from the reference water jacket number, locate the leaking area on the outer layer of the steel beam water jacket, and close the water jacket circulating water inlet valve after locating;

[0012] (2) Water jacket outer opening

[0013] Taking the inner layer leakage point of the water jacket as the center, use a gas cutting gun to cut the steel plate with a size of 200X300mm-300X400mm at the corresponding position of the outer layer of the water jacket, and hollow out the area where the water jacket reinforcement plate is located as the working surface to expose the inner layer leakage point in the water jacket cavity of the steel beam;

[0014] (3) Repair welding of leaking spots in water jacket cavity

[0015] Use a polisher to grind the leaking point in the water jacket cavity and the original welds nearby to ensure that the surface is smooth and free of rust, scale, iron corrosion and other foreign matter. Use refractory soil to build a local dam to block the water accumulation in the area, and use a gas cutting torch flame to bake the surface at a high temperature of more than 300℃ to dry out the moisture;

[0016] (3.1) Repair welding method when the leak point is a weld crack

[0017] When it is the leak point of the weld crack, drill more than 2mm into the two ends of the crack on the inner layer b side with a drill bit of 8-10mm diameter, grind a weld with a depth of 2mm and a width of 5-8mm along the crack between the two points, use a DC welding machine to fully weld the J507 electrode in 2-3 times, and knock the weld and the cladding layer while they are in a hot state to reduce the shrinkage of the weld and reduce the internal stress; weld and fix the two ends of the weld crack to prevent thermal expansion and the formation of secondary cracks; use J507 welding rod to enhance welding force to avoid the expansion and secondary bursting caused by the heat of high-temperature smoke outside and water cooling inside.

[0018] (3.2) Repair welding method for leaks with a diameter of more than 5 mm

[0019] When the leak is a hole with a diameter of more than 5mm, first use a cylindrical grinder to enlarge the leak to an elliptical hole, use a Q245R steel plate rectangle with a thickness of 10-15mm and chamfer it, control the size of the steel plate rectangle length>hole opening length, hole opening width<steel plate rectangle width<hole opening length, use welding rods to weld vertically on the steel plate rectangle, use welding rods to tilt the steel plate rectangle from the b side of the hole to the a side, and then use welding rods to tighten the rectangle and stick it parallel to the a side of the hole, use a DC welding machine to weld along the hole, remove the welding slag and gradually use J507 welding rods to weld the inner wall of the hole for 2-3 times to make it smooth, while the weld and the surfacing layer are in a hot state, knock them to reduce the shrinkage of the weld and reduce the internal stress, and after grinding with a grinder, take the same size Q245R A rectangular steel plate is attached to the original hole position on the b side for welding. While the weld and the weld cladding layer are still hot, they are hammered with a hammer to reduce the shrinkage of the weld and reduce internal stress. A rectangular steel plate on the a side and a rectangular steel plate on the b side are used, as well as J507 welding rods, to repair the inner wall of the hole. Three-layer welding is used to enhance the welding stress and dynamic load resistance. Q245R plate material is used to enhance corrosion resistance, and the overall service life is increased by more than 3 months after repair.

[0020] (4) Welding and leak detection of the outer area of ​​the water jacket

[0021] A V-shaped groove is made on the cracks on the outer side of the cut and removed water jacket, and the cracks are polished clean. A V-shaped groove is made on the welded joints of the steel beam water jacket, and the cracks are polished. The top width of the V-shaped groove is 8-10mm. Stop holes of φ8-10mm are made at both ends of the cracks, and then carbon dioxide gas shielded welding is used for welding. After welding is completed and the weld has cooled for 30 minutes, water is passed through the water jacket for pressure testing to detect leaks. After the test is qualified, the furnace is put into production.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. Simple operation and short time. Compared with the traditional technology, the present invention reduces the process of removing the water jacket, forced ventilation detection, building scaffolding in the furnace, dismantling the scaffolding in the furnace, installing the water jacket, and the preparation of corresponding tools. Instead, the present invention adds the process of cutting and repairing the outer layer of the steel beam water jacket; compared with the complicated disassembly and assembly of the water jacket, erection and disassembly of the scaffolding, and limited space operations, the operation process of the present invention is simple, highly operable, and the time consumption is reduced by half.

[0024] 2. The risk is very small. In the traditional technology, during the disassembly and assembly of the water jacket, the weight of the water jacket is close to

[0025] 1 ton, so the lifting, transfer and installation processes all require the use of manual hoists and the assistance of multiple people, and there is a risk of being hit by objects; working in a confined space, there is a risk of falling objects from high altitude, being hit by objects, and poisoning and suffocation. The off-furnace maintenance adopted in the present invention avoids the above operations and eliminates the above risks.

[0026] 3. Different welding repair methods are used for different leakage points in the steel beam water jacket. The two ends of the weld crack leakage point are welded and fixed to prevent the formation of secondary cracks due to heat expansion; for the hole leakage point, the inner layer of the steel beam water jacket a side steel plate rectangular block repair welding and the b side steel plate rectangular block repair welding are used. The holes are filled with welding rods in the middle. Three-layer repair welding is used to enhance the corrosion resistance and dynamic load resistance, enhance the welding force, and increase the overall service life by more than 3 months after repair. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG1 is a schematic diagram showing the positions of the inner and outer layers of the water jacket of a steel beam according to the present invention. DETAILED DESCRIPTION

[0028] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0029] As shown in FIG1 , a method for repairing water leakage inside a steel beam water jacket furnace outside the furnace comprises:

[0030] (1) Leak point location

[0031] The steel beam water jacket is a two-layer structure with a reinforcing rib plate in the middle. The inner layer is the layer close to the furnace. The side of the inner layer located in the furnace is side a, and the side located outside the furnace is side b. When the inner layer leaks, the side-blowing furnace stops feeding, turns off oxygen, closes the air inlet and enters the insulation state to ensure the normal operation of the circulating water. Through the observation hole in front of the furnace and the water jacket drain outlet, use a strong flashlight to find the corrosion and leakage points of the inner layer of the steel beam water jacket. Lock the corresponding leaking water jacket position number of the inner layer according to the up, down, left and right distances. Take the number of water jacket plates closest to the observation hole and drain outlet of the inner layer leaking water jacket plate number as a reference, compare the size and position of the outer edge of the steel beam water jacket from the reference water jacket plate number, locate the leaking area on the outer layer of the steel beam water jacket, and close the water jacket circulating water inlet valve after locating.

[0032] (2) Water jacket outer opening

[0033] Taking the leakage point of the inner layer of the water jacket as the center, use a gas cutting gun to cut a steel plate of 250X350mm at the corresponding position of the outer layer of the water jacket, and hollow out the area where the water jacket reinforcement plate is located as the working surface to expose the inner layer leakage point in the water jacket cavity of the steel beam.

[0034] (3) Repair welding of leaking spots in water jacket cavity

[0035] Use a grinder to grind the leaking point in the water jacket cavity and the original welds nearby to ensure a smooth surface free of rust, scale, iron corrosion and other foreign matter. Use refractory soil to build a local dam to block the accumulated water in the area, and use a gas cutting gun flame to bake the surface at a high temperature of more than 300°C to dry out the moisture.

[0036] (3.1) Repair welding method when the leak point is a weld crack

[0037] When it is the leak point of the weld crack, use a 9mm diameter drill bit to drill more than 2mm at both ends of the crack on the inner layer b side, grind a 2mm deep and 7mm wide weld along the crack between the two points, use a DC welding machine to fully weld the J507 electrode 2-3 times, and knock the weld and the cladding layer while they are in a hot state to reduce the shrinkage of the weld and reduce internal stress; weld and fix both ends of the weld crack to prevent thermal expansion and the formation of secondary cracks; use J507 welding rod to enhance welding force to avoid secondary explosion caused by external high-temperature smoke and internal water cooling.

[0038] (3.2) Repair welding method for leaks with a diameter of more than 5 mm

[0039] When the leak is a hole with a diameter of more than 5mm, first use a cylindrical grinder to enlarge the leak to an elliptical hole, use a Q245R steel plate rectangle with a thickness of 10-15mm and chamfer it, control the size of the steel plate rectangle length>hole opening length, hole opening width<steel plate rectangle width<hole opening length, use welding rods to weld vertically on the steel plate rectangle, use welding rods to tilt the steel plate rectangle from the b side of the hole to the a side, and then use welding rods to tighten the rectangle and stick it parallel to the a side of the hole, use a DC welding machine to weld along the hole, remove the welding slag and gradually use J507 welding rods to weld the inner wall of the hole for 2-3 times to make it smooth, while the weld and the surfacing layer are in a hot state, knock them to reduce the shrinkage of the weld and reduce the internal stress, and after grinding with a grinder, take the same size Q245R A rectangular steel plate is attached to the original hole position on the b side for welding. While the weld and the weld cladding layer are still hot, they are hammered with a hammer to reduce the shrinkage of the weld and reduce internal stress. A rectangular steel plate on the a side and a rectangular steel plate on the b side are used, as well as J507 welding rods, to repair the inner wall of the hole. Three-layer welding is used to enhance the welding stress and dynamic load resistance. Q245R plate material is used to enhance corrosion resistance, and the overall service life is increased by more than 3 months after repair.

[0040] (4) Welding and leak detection of the outer area of ​​the water jacket

[0041] Due to the large welding area and the steel beam water jacket is made of Q245R, which is a low-alloy high-strength structural steel, and the welding area is large, the welding process adopts carbon dioxide gas shielded welding, which has high welding productivity, good crack resistance and small welding deformation; due to the long weld and the circulating water has a certain pressure, in order to prevent the weld from cracking, the weld is treated as follows: 1) Drilling stop holes of φ9mm at both ends of the crack to prevent the crack from further expanding outward during welding; 2) Using a manual grinder to open a groove at the crack position, the groove top width is 9mm, slightly V-shaped, so that the welding liquid can fully enter.

[0042] A V-shaped groove is made on the crack of the outer side of the cut and removed water jacket, and the crack is polished clean. The welded joints of the cut steel beam water jacket are treated in the same way, with a groove top width of 9mm. Stop holes of φ9mm are opened at both ends of the crack, and then carbon dioxide gas shielded welding is used. After welding is completed and the weld has cooled for 30 minutes, water is passed through the water jacket for pressure testing to detect leaks. After the test is qualified, the furnace is put into production.

[0043] Compared with the prior art, the present invention is simple to operate and takes less time. The present invention reduces the process of removing the water jacket, forced ventilation testing, building scaffolding in the furnace, dismantling the scaffolding in the furnace, installing the water jacket, and the preparation of corresponding tools. Instead, the present invention adds the process of cutting and repairing the outer layer of the steel beam water jacket. Compared with the complicated disassembly and assembly of the water jacket, the erection and disassembly of scaffolding, and confined space operations, the operation process of the present invention is simple, highly operable, and the time consumption is reduced by half. The risk is very small. In the traditional technology, during the disassembly and assembly of the water jacket, since the weight of the water jacket is close to 1 ton, the hoisting, transfer, and installation processes all require the use of manual hoists and the assistance of multiple people, and there is a risk of being hit by objects. There is a risk of falling objects, being hit by objects, and poisoning and suffocation in confined space operations. Different welding repair methods are used for different leakage points in the steel beam water jacket. The two ends of the weld crack leakage point are welded and fixed to prevent the formation of secondary cracks due to heat expansion. For the hole leakage point, the inner layer a-side steel plate rectangular block and the b-side steel plate rectangular block are used for repair welding, and the hole is filled with welding rods in the middle. Three-layer repair welding enhances the corrosion resistance and dynamic load resistance, enhances the welding force, and increases the overall service life by more than 3 months after repair.

[0044] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for repairing water leakage inside a steel beam water jacket furnace outside the furnace, characterized in that: include: (1) Leak point location The steel beam water jacket is a two-layer structure with a reinforcing rib plate in the middle. The inner layer is the layer close to the furnace. The inner layer is located on the side inside the furnace, which is called side a, and the inner layer is located on the side outside the furnace, which is called side b. When the inner layer leaks, the side-blowing furnace stops feeding, turns off oxygen, closes the air inlet and enters the insulation state to ensure the normal operation of the circulating water. The corrosion and leakage points of the inner layer of the steel beam water jacket are found through the observation hole in front of the furnace and the sewage outlet of the water jacket. The leakage area is located by comparing with the corresponding position of the outer layer. After locating, the circulating water inlet valve of the water jacket is closed; Specifically, the upper, lower, left, and right distances in the water jacket cavity are observed through the furnace front observation hole and the water jacket drain port to lock the corresponding leaking water jacket plate position number of the inner layer. The number of water jacket plates closest to the observation hole and drain port of the inner layer leaking water jacket plate position number is used as a reference, and the size and position of the outer edge of the steel beam water jacket from the reference water jacket plate number are compared to locate the leaking area on the outer layer of the steel beam water jacket; (2) Water jacket outer opening Taking the inner layer leakage point of the water jacket as the center, cut the steel plate with a size of 200X300mm or more at the corresponding position of the outer layer of the water jacket, and hollow out the area where the water jacket reinforcement plate is located as the working surface to expose the inner layer leakage point in the water jacket cavity of the steel beam; (3) Repair welding of leaking spots in water jacket cavity Grind the leaking point in the water jacket cavity and the original welds nearby to ensure that there are no foreign objects on the surface. Use refractory soil to build a local dam to block the water in the leaking area, and dry the surface at a high temperature of more than 300℃. Use different welding repair methods for different leaking points. When the leaking point is a weld crack, weld and fix the two ends of the weld crack. When it is a weld crack leak, use a drill bit with a diameter of 8-10mm to drill more than 2mm deep at both ends of the crack on the inner layer b side, grind a 2mm deep and 5-8mm wide weld along the crack between the two points, use a welding machine to fully weld the electrode 2-3 times, and knock while the weld and the cladding layer are in a hot state; When the leak point is a hole-shaped leak point with a diameter of more than 5mm, the inner layer a side steel plate rectangular block welding and b side steel plate rectangular block welding are used for the hole-shaped leak point, and the middle is filled with welding rods and three layers of repair welding are used; for a diameter of 5mm When the above hole-shaped leak point, use a grinder to enlarge the leak point to an elliptical hole, use a steel plate rectangular block with a length greater than the hole length, a width greater than the hole width and less than the hole length, and chamfer it, and weld it vertically on the steel plate rectangular block with a welding rod, and use the welding rod to tilt the steel plate rectangular block from the hole b side to the a side, and then use the welding rod to tighten the rectangular block and parallel to the hole a side for welding. After welding is completed and the welding slag is removed, use the welding rod to repair the inner wall of the hole and make it flat. While the weld and the cladding layer are in a hot state, knock them. After grinding with a grinder, finally use a steel plate rectangular block of the same size to stick it to the original hole position on the b side for welding, and knock them while the weld and the cladding layer are in a hot state; (4) Welding and leak detection of the outer area of ​​the water jacket A V-shaped groove is made on the crack of the outer layer of the water jacket that is cut and removed, and the crack is polished clean at the same time. A V-shaped groove is made on the welding joint of the steel beam water jacket that is cut and removed, and the crack is also polished. Stop holes are made at both ends of the crack, and then welding is carried out. After welding is completed and the weld has cooled for 30 minutes, water is passed through the water jacket to test for leaks. After the test is qualified, the furnace is put into production.

2. The method for repairing water leakage inside a steel beam water jacket furnace outside a furnace according to claim 1, characterized in that: The welding rod model is J507.

3. The method for repairing water leakage inside a steel beam water jacket furnace outside a furnace according to claim 1, characterized in that: The thickness of the steel plate rectangular block is 10-15 mm.

4. The method for repairing water leakage inside a steel beam water jacket furnace outside a furnace according to claim 1, characterized in that: The welding rod model is J507, and the material of the steel plate rectangle is Q245R.

5. The method for repairing water leakage inside a steel beam water jacket furnace outside a furnace according to claim 1, characterized in that: The top width of the V-shaped groove is 8-10mm; the size of the crack stop hole is φ8-10mm.

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