A blow-type tundish nozzle repairing device and method

Abstract

The application discloses a blowing type tundish repairing device and method, and belongs to the technical field of iron and steel metallurgy. The device comprises a converter and a self-clamping steel pipe. The side wall of the converter is provided with a tundish, and the inner wall of the tundish is provided with a blowing pipe. The blowing pipe is internally connected with a flow pipe group. The self-clamping steel pipe is sleeved in the blowing pipe and has a gap of 3mm-15mm with the blowing pipe. The gap between the blowing pipe and the self-clamping steel pipe is filled with grouting material. The flow pipe group is in communication with the inside of the converter. When the converter is normally charged, the self-clamping steel pipe is inserted into the tundish. The gap between the self-clamping steel pipe and the tundish is filled with the grouting material by gravity, the eroded part is filled and smoothed, the tundish eroded part is automatically repaired, and no external force equipment and tools are needed. The process is simple, and the repairing efficiency is high. In addition, the repairing method can repair the eroded part without damaging the original structure of the blowing pipe.

Description

Technical Field

[0001] This invention belongs to the field of iron and steel metallurgy technology, specifically a repair device and method for an air-blowing steel tapping outlet. Background Technology

[0002] Converter smelting utilizes an oxygen lance to inject supersonic oxygen, oxidizing oxidizable impurities such as carbon, silicon, manganese, and phosphorus in the molten iron. As the amount of impurities in the molten steel gradually decreases, the oxides of these impurities in the slag increase. This slag flows out along with the molten steel during tapping. Therefore, slag blocking is essential during converter tapping. Traditionally, slag-blocking markers (balls) or sliding plates were used, or a combination of both.

[0003] During the final stages of converter tapping, after most of the molten steel has been discharged, slag accumulates above the taphole due to confluence vortices and drainage pits, severely impacting steel quality and reducing steel yield. Existing technologies employ a pre-embedded air-blowing structure within the taphole. During tapping, the injected gas disrupts the vortices generated by the molten steel, thereby eliminating slag entrapment and achieving steel-slag separation.

[0004] However, during the use of this technology, it was found that the erosion rate at the gas outlet end of the tapping spout was much faster than that of other parts of the converter, resulting in a difference in the lifespan of the tapping spout compared to the overall lifespan of the converter. Existing repair techniques involve drilling and breaking up the severely eroded tapping spout, installing a new tapping spout, and then grouting it for shaping. If a sliding plate is installed, it also needs to be repositioned, making the process complex and disruptive to production. Summary of the Invention

[0005] The purpose of this invention is to provide a repair device and method for a gas-blown steel tapping spout, which enables rapid repair of the gas outlet end of the gas-blown steel tapping spout while repairing the furnace, so that the steel tapping spout and the converter as a whole can achieve the same service life, thereby solving the problems mentioned in the prior art.

[0006] A repair device for an air-blown steel tapping spout is provided, comprising:

[0007] A converter, wherein a steel tapping port is provided on the side wall of the converter, and a blow pipe is provided on the inner wall of the steel tapping port, and a flow pipe assembly is connected inside the blow pipe;

[0008] The self-locking steel pipe is sleeved inside the injection pipe with a gap of 3mm to 15mm between them. The gap between the injection pipe and the self-locking steel pipe is filled with grout. The flow pipe assembly is connected to the interior of the converter.

[0009] As a further aspect of the present invention, the gap between the blow pipe and the self-locking steel pipe is 5mm to 10mm.

[0010] As a further aspect of the present invention: the insertion end of the self-clamping steel pipe protrudes from the inner wall of the converter and the protrusion dimension is 50mm to 100mm.

[0011] As a further aspect of the present invention, the self-locking steel pipe is welded with connecting ribs on its exterior.

[0012] As a further aspect of the present invention: the grouting material is at least one of magnesium castable, silica castable or alumina castable.

[0013] In another aspect, the present invention provides a method for repairing an air-blowing steel tapping spout, including the aforementioned air-blowing steel tapping spout repair device, specifically comprising the following steps:

[0014] S1. Insert the self-clamping steel pipe into the steel outlet;

[0015] S2. Rotating converter, so that the inner wall of the converter with the tapping port close to the converter opening forms an angle of α degrees with the horizontal plane, and the angle α is 5° to 20°.

[0016] S3. Grouting material is filled from the furnace mouth of the converter into the gap between the self-locking steel pipe and the injection pipe;

[0017] S4. When the grouting material accumulates between the converter and the tapping port 2, inert gas is sprayed into the grouting material through the flow pipe group. After the grouting material is sintered and solidified, a flow channel is formed that connects the flow pipe group with the inside of the converter.

[0018] As a further aspect of the present invention: the grouting material is filled to a distance of 3mm to 10mm from the end of the self-locking steel pipe.

[0019] As a further aspect of the present invention: the inert gas has a flow pressure of 0.5MPa to 1MPa and a flow velocity of 100m / s to 150m / s.

[0020] As a further aspect of the present invention, the inert gas is nitrogen or argon.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] During normal furnace repair in the converter, a self-locking steel pipe is inserted into the taphole. Grouting material flows by itself to fill the gap between the self-locking steel pipe and the taphole, smoothing out the corroded area and achieving automatic repair of the corroded area at the taphole. This process is simple and highly efficient, requiring no external force or tools. Furthermore, the repair method provided by this invention can repair corroded areas without damaging the original blowpipe structure. Attached Figure Description

[0023] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0024] Figure 1 This is a schematic diagram of the installation of the self-locking steel pipe provided by the present invention;

[0025] Figure 2 This is a schematic diagram of the repair process for an air-blown steel tapping spout.

[0026] Figure 3 for Figure 2 Enlarged view of region A in the middle;

[0027] Figure 4 This is a schematic diagram of the overall structure of the converter.

[0028] In the diagram: 1. Converter; 2. Taphole; 3. Injection pipe; 31. Flow pipe assembly; 4. Self-locking steel pipe; 41. Connecting rib; 5. Air passage. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, and not all embodiments. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0030] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0031] Please see Figure 1-4 As shown in the embodiment of the present invention, a repair device and method for a blown steel tapping spout includes a converter 1 and a self-locking steel pipe 4. A tapping spout 2 is provided on the side wall of the converter 1, and a blow-through pipe 3 is provided on the inner wall of the tapping spout 2. A flow pipe assembly 31 is connected to the inside of the blow-through pipe 3. The self-locking steel pipe 4 is sleeved inside the blow-through pipe 3 with a gap of 3mm to 15mm between them. The gap between the blow-through pipe 3 and the self-locking steel pipe 4 is filled with grout. The flow pipe assembly 31 is connected to the inside of the converter 1.

[0032] The taphole 2 is the channel for the outflow of molten steel and slag. A blowpipe 3 is installed at the taphole 2, and the blowpipe 3 is internally connected to a flow pipe assembly 31, used to disrupt the vortex generated by the molten steel during tapping by blowing gas. The flow pipe assembly 31 includes several blowing pipes 311, an annular gas chamber 312, and an inlet pipe 313 arranged sequentially along the tapping direction of the molten steel. The inlet pipe 313 is connected to the several blowing pipes 311 through the annular gas chamber 312. After gas is introduced into the inlet pipe 313, the gas is redistributed through the annular gas chamber 312 and then blown into the molten steel inside the converter 1 through the several blowing pipes 311. Because the blowpipe 3 and the connection between the blowpipe 3 and the taphole 2 are affected by the erosion of high-temperature molten steel and slag, these parts will suffer structural damage, resulting in thinning of the structural layer.

[0033] Therefore, during repair, a gap of 3mm to 15mm needs to be reserved between the self-locking steel pipe 4 and the jet pipe 3. This ensures that the self-locking steel pipe 4 can compensate for the eroded portion while guaranteeing that the grout can overcome tension and flow through the gap to fill it, and that there is a sufficient thickness of grout between the self-locking steel pipe 4 and the jet pipe 3. The grout is a high-temperature refractory material that forms a protective layer after being filled between the self-locking steel pipe 4 and the jet pipe 3. This prevents high-temperature molten steel or slag from contacting the jet pipe 3 and causing corrosion, thus extending the service life of the jet pipe 3.

[0034] Preferably, the gap between the blowpipe 3 and the self-locking steel pipe 4 is 5mm to 10mm. The wall thickness of the blowpipe 3 should not be too large to ensure that the blowpipe 3 has an effective and stable wall thickness structure. Therefore, repair is required when the corrosion reaches a certain depth. The inner diameter of the self-locking steel pipe 4 should not be too small to prevent the self-locking steel pipe 4 from occupying too much of the original steel tapping space, which would reduce the steel tapping efficiency.

[0035] The self-clamping steel pipe 4 protrudes 50mm to 100mm from the inner wall of the converter 1. Grouting material is filled to a distance of 5mm to 10mm from the protruding end of the self-clamping steel pipe 4. Since the main erosion zone of the converter 1 is located at the connection between the end of the tapping port 2 and the inner wall of the converter 1, after the grouting material fills the gap between the injection pipe 3 and the self-clamping steel pipe 4, the amount of grouting material needs to be increased to repair and strengthen this main erosion zone, ensuring the grouting material is submerged to a certain height and increasing the protection area. After being raised, the grouting material gradually covers the outside of the self-clamping steel pipe 4, filling to a distance of 3mm to 10mm from the protruding end of the self-clamping steel pipe 4. This prevents leakage from the pipe opening during filling and allows molten steel to flow smoothly out of the self-clamping steel pipe 4 without excessive molten steel retention.

[0036] The self-locking steel pipe 4 is externally welded with connecting ribs 41. The length of the connecting ribs 41 is determined based on the gap between the blowpipe 3 and the self-locking steel pipe 4. The self-locking steel pipe 4 extends from the outside of the outlet 2 inwards and achieves self-locking and limiting through the interaction between the connecting ribs 41 and the blowpipe 3, eliminating the need for additional connecting components such as flanges and reducing installation difficulty. Furthermore, after the grout solidifies in the gap between the self-locking steel pipe 4 and the blowpipe 3, the grout and connecting ribs 41 will bond tightly, enhancing the connection strength between the self-locking steel pipe 4 and the grout. This acts as a framework to improve the overall strength of the grout and prevent the self-locking steel pipe 4 from detaching under external forces. Since the actual length of the connecting ribs 41 is determined by the corrosion situation, there is no universal standard part for the connecting ribs 41, and the length of the connecting ribs 41 needs to be adjusted according to actual usage. Therefore, after the connecting ribs 41 are processed, they are welded to the self-locking steel pipe 4, improving the flexibility of the repair device.

[0037] The grouting material is at least one of the following refractory cements: magnesia castable, silica castable, or alumina castable. Magnesia castable has good corrosion resistance, can resist the erosion of molten metal and slag, protects the blowpipe 3 and the steel outlet 2 from corrosion, and extends the service life of the protected structure.

[0038] Siliceous castable is a refractory material made primarily from siliceous sand. It possesses high hardness and wear resistance, and can form a protective layer at high temperatures. Aluminaic grouting material, made primarily from aluminates or ferroaluminates, exhibits high temperature resistance, maintaining structural stability at high temperatures. It also provides good sealing properties, forming an insulating layer to reduce the penetration of molten metal and slag. Refractory cement hardens rapidly after application, forming a robust grout layer with excellent bonding properties, ensuring a firm connection between the blowpipe 3 and the self-locking steel pipe 4. Furthermore, refractory cement maintains structural stability and durability at high temperatures. In addition, these materials can be combined to create grouting materials that achieve different protective effects, based on their specific characteristics.

[0039] Please see Figure 2 and Figure 3 As shown, another aspect of the present invention provides a repair method for an air-blowing steel tapping spout, including the aforementioned repair device for an air-blowing steel tapping spout, specifically including the following steps:

[0040] S1. Insert the self-clamping steel pipe 4 into the steel outlet 2.

[0041] S2. Rotate converter 1 so that the inner wall of converter 1 with the tapping port 2 close to the furnace opening of converter 1 forms an angle of α degrees with the horizontal plane, and the angle α is 5° to 20°.

[0042] S3. Grouting material is filled from the furnace opening of converter 1 into the gap between self-locking steel pipe 4 and injection pipe 3.

[0043] S4. When the grouting material is piled up between the converter 1 and the tap 2, inert gas is sprayed into the grouting material through the flow pipe group 31. After the grouting material is sintered and solidified, a flow channel 5 is formed that connects the flow pipe group 31 with the interior of the converter 1.

[0044] Since the initial angle of the taphole 2 may be unfavorable for repair work, the angle of the converter 1 needs to be adjusted so that the taphole 2 faces the bottom as much as possible, and the furnace opening of the converter 1 faces the working surface suitable for personnel. The inner wall of the converter 1 near the furnace opening of the taphole 2 forms an angle α with the horizontal plane, and the angle α is 5° to 20°. This angle range allows the grout to flow to the filling area by its own fluidity and gravity when added to the inner wall of the converter 1, without the need for tool-assisted transportation or insertion into the interior of the converter 1.

[0045] The original injection pipe 3 has its inlet set at the same height as or slightly below the inner wall of converter 1. However, when the grout is filled, it will block the inlet of the flow pipe assembly 31. To ensure that the injection pipe 3 can maintain its original gas injection function, an airflow channel needs to be formed between the outlet of the flow pipe assembly 31 and the inner cavity of converter 1 during the solidification process of the grout. A common method is to support a tubular template on the injection pipe 3. After the grout solidifies, an airflow channel is formed inside the tubular template. However, this method requires operation from inside converter 1, which is complex and dangerous.

[0046] Therefore, this invention continuously supplies inert gas to the flow pipe assembly 31 during the grout solidification process. The inert gas acts as a template separator, ensuring that a gas flow cavity is always formed between the flow pipe assembly 31 and the inner cavity of the converter 1. After the grout is sintered and formed, the air passage 5 is naturally formed. This method eliminates the need for operations inside the converter 1 and the construction of additional templates, fully utilizing the existing structure and function of the flow pipe assembly 31. The formed air passage 5 is naturally formed and does not affect the subsequent use of the injection pipe 3.

[0047] To ensure the shape of the air passage 5 meets the requirements, the inert gas flow pressure is 0.5MPa to 1MPa, and the flow velocity is 100m / s to 150m / s. Within this pressure and velocity range, the gas template formed by the inert gas can effectively prevent the grout from covering the flow pipe assembly 31. Furthermore, the pressure and velocity must not be too high to prevent grout from splashing during inert gas injection, which could lead to unstable formation of the air passage 5.

[0048] Furthermore, the inert gas is nitrogen or argon. Nitrogen and argon are extremely stable and generally do not react with other substances, nor do they corrode the grouting material or the interior of converter 1. Nitrogen and argon are relatively abundant in the atmosphere, making them relatively easy and inexpensive to obtain, and high-purity gas sources are readily available.

[0049] The above description is merely an example and illustration of the structure of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the structure of the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A method for repairing an air-blown steel tapping spout, comprising a repair device, characterized in that: The repair device includes a converter (1) and a self-locking steel pipe (4), the self-locking steel pipe (4) having connecting ribs (41) welded to its exterior. The converter (1) has a steel outlet (2) on its side wall, and a blow pipe (3) is provided on the inner wall of the steel outlet (2). The blow pipe (3) is connected to a flow pipe group (31). The self-locking steel pipe (4) is fitted inside the injection pipe (3) and there is a gap of 3mm to 15mm between them. The gap between the injection pipe (3) and the self-locking steel pipe (4) is filled with grout. The flow pipe assembly (31) is connected to the interior of the converter (1). The insertion end of the self-locking steel pipe (4) protrudes from the inner wall of the converter (1) and the protrusion size is 50mm to 100mm. The grout is filled to a distance of 5mm to 10mm from the insertion end of the self-locking steel pipe (4). The repair method specifically includes the following steps: S1. Insert the self-clamping steel pipe (4) into the steel outlet (2); S2, Rotate the converter (1) so that the tapping port (2) is close to the converter (1) and the inner wall of the converter (1) in the direction of the furnace mouth forms an angle of α degrees with the horizontal plane and the angle of α is 5°~20°; S3. Grouting material is filled from the furnace mouth of the converter (1) into the gap between the self-clamping steel pipe (4) and the injection pipe (3); S4. When the grouting material is piled up between the converter (1) and the tapping port (2), inert gas is sprayed into the grouting material through the flow pipe group (31). After the grouting material is sintered and solidified, a flow channel (5) is formed that connects the flow pipe group (31) with the interior of the converter (1). The inert gas has a flow pressure of 0.5 MPa to 1 MPa and a flow velocity of 100 m / s to 150 m / s.

2. The repair method for an air-blowing steel tapping spout according to claim 1, characterized in that, The gap between the blow pipe (3) and the self-locking steel pipe (4) is 3mm to 10mm.

3. The repair method for an air-blowing steel tapping spout according to claim 1, characterized in that, The grouting material is at least one of magnesium castable, silica castable, or aluminum castable.

4. The repair method for an air-blowing steel tapping spout according to claim 1, characterized in that, The inert gas is nitrogen or argon.

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