A device for improving the level of continuous casting protection pouring

Abstract

The utility model relates to a device for improving the protection pouring level of continuous casting, which comprises an argon sealing ring sleeved at the lower end of a tundish nozzle and a gas delivery pipe fixed to one end of the argon sealing ring, the inner cavity of the argon sealing ring is in communication with the gas delivery pipe, the other end of the argon sealing ring is sealed, and the bottom surface of the argon sealing ring is provided with a plurality of gas injection holes arranged in a circumferential direction at intervals. The range of gas injection of each gas injection hole is closed in the circumferential direction. The utility model provides a channel for the input of argon gas by arranging the gas delivery pipe and the argon sealing ring, so that an air curtain is formed around the connecting gap between the tundish nozzle and the external submerged entry nozzle, thereby avoiding the entry of air into the connecting gap and causing secondary oxidation of molten steel.

Description

Technical Field

[0001] This utility model relates to the field of casting equipment technology, and in particular to a device for preventing secondary oxidation during the casting of molten steel, specifically a device for improving the level of protective casting in continuous casting. Background Technology

[0002] In the existing technology for continuous casting of specialty steels, there are a number of problems that affect product quality and production efficiency.

[0003] When using a sliding block sizing nozzle, turbulence is a significant problem. For grade steels such as 40Cr, 25MnB, and Q355B, during continuous casting, due to the structural characteristics of the sliding block sizing nozzle and the flow properties of molten steel, irregular turbulent flow, or turbulence, easily occurs as the molten steel passes through the nozzle. This severely affects the castability of the molten steel, reduces the stability of the continuous casting process, increases the difficulty of production operations, and easily leads to various quality defects in the cast billet, such as surface cracks and internal inclusions.

[0004] While the external, separate sprue nozzle method offers certain advantages, it also has significant drawbacks. A gap exists between the tundish nozzle and the external submersible nozzle, allowing air to be drawn in during molten steel pouring due to negative pressure. This air intrusion leads to secondary oxidation of the molten steel, significantly increasing its oxygen content. Simultaneously, nitrogen from the air is also drawn into the molten steel, causing nitrogen enrichment. This oxygen and nitrogen enrichment severely impacts the cleanliness of the steel, resulting in more inclusions, reduced mechanical properties, and shorter service life, failing to meet the high quality requirements for specialty steels. Utility Model Content

[0005] This invention addresses the shortcomings of existing technologies by providing a device to improve the protective pouring level in continuous casting, preventing air from entering the gap between the tundish nozzle and the external submersible nozzle, thereby avoiding secondary oxidation of the molten steel.

[0006] This utility model is achieved through the following technical solution, providing a device for improving the level of continuous casting protection pouring, including an argon sealing ring sleeved on the lower end of the tundish nozzle, and a gas supply pipe fixedly connected to one end of the argon sealing ring. The inner cavity of the argon sealing ring is connected to the gas supply pipe, and the other end of the argon sealing ring is sealed. The bottom surface of the argon sealing ring is provided with a plurality of air jet holes, which are arranged sequentially at intervals along the circumference, and the range of gas ejected from each air jet hole is closed along the circumference.

[0007] When in use, this scheme introduces argon gas into the gas supply pipe. The argon gas is ejected through the jet nozzle and forms a cylindrical gas curtain in the connection area between the tundish nozzle and the external submersible nozzle. The gas curtain formed by the argon gas blocks oxygen and nitrogen in the air, preventing oxygen and nitrogen from coming into contact with the molten steel.

[0008] As an optimization, this solution also includes a lifting hook and an anti-rotation block fixedly connected to the gas pipeline. The anti-rotation block has a rectangular cross-section perpendicular to the axis of the gas pipeline. The lifting hook includes a lifting rod, a first hook fixed to the upper end of the lifting rod, and a second hook fixed to the lower end of the lifting rod. The width of the second hook is adapted to the width of the anti-rotation block's cross-section perpendicular to the axis of the gas pipeline. This optimized solution facilitates the support of the gas pipeline by providing a lifting hook, and prevents the gas pipeline from rotating on its own during use by providing an anti-rotation block.

[0009] As an optimization, the gas delivery pipe passes through the anti-rotation block axially, and the anti-rotation block has a through hole that matches the outer diameter of the gas delivery pipe. The gas delivery pipe is then welded and fixed to the anti-rotation block. This optimized solution fixes the gas delivery pipe to the anti-rotation block, making the fixing method simple, reliable, and easy to manufacture.

[0010] As an optimization, the plane containing the first hook is perpendicular to the plane containing the second hook, and the opening width of the first hook is adapted to the horizontal axis fixed to the outer shell of the intermediate package. This optimized design allows for direct use of the original horizontal axis of the intermediate package outer shell, making it more convenient to use.

[0011] As an optimization, the vertical projection of the first hook is located on the side of the vertical projection of the second hook closer to the argon sealing ring. This optimized design allows operators to easily attach the hook forward during operation.

[0012] As an optimization, the gas delivery pipe and argon sealing ring are integrally bent and formed, with the end of the gas delivery pipe furthest from the argon sealing ring connected to a flexible metal hose. This optimized design integrates the gas delivery pipe and argon sealing ring into a single bent shape, eliminating the need for welding, making manufacturing more convenient, completely preventing leaks at weld seams, and facilitating operation of the device by connecting it to a flexible metal hose, thus improving the flexibility of use.

[0013] The beneficial effects of this utility model are as follows: by setting up a gas supply pipe and an argon sealing ring, a channel is provided for the introduction of argon gas, so that the argon gas forms an air curtain around the connection gap between the tundish nozzle and the external submersible nozzle, preventing air from entering the connection gap and causing secondary oxidation of the molten steel. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a side view of the present invention; Figure 3 for Figure 2 Sectional view of AA; Figure 4 for Figure 3 Side view; Figure 5 This is a schematic diagram of the jet hole distribution; As shown in the figure: 1. Argon sealing ring, 2. Gas supply pipe, 3. First hook body, 4. Anti-rotation block, 5. Lifting hook, 6. Second hook body, 7. Gas outlet. Detailed Implementation

[0015] To clearly illustrate the technical features of this solution, the following detailed implementation method will be used to explain the solution.

[0016] like Figure 1 The device shown is for improving the protective casting level of continuous casting. It includes an argon sealing ring 1 sleeved at the lower end of the tundish nozzle and a gas supply pipe 2 fixedly connected to one end of the argon sealing ring. The end of the gas supply pipe away from the argon sealing ring is connected to a metal flexible tube. The inner cavity of the argon sealing ring 1 is connected to the gas supply pipe 2. The other end of the argon sealing ring is sealed. The bottom surface of the argon sealing ring 1 has a plurality of air jet holes 7. The air jet holes 7 are arranged sequentially and spaced apart along the circumference. The arc length between two adjacent air jet holes is not greater than 1 / 10 of the circumference of the argon sealing ring. The range of gas ejected from each air jet hole is closed along the circumference. After the argon gas is ejected from the air jet hole, it forms a cylindrical gas curtain located outside the gap between the tundish nozzle and the external submersible nozzle.

[0017] To facilitate support of the gas pipeline, the device in this embodiment also includes a hook 5 and an anti-rotation block 4 fixedly connected to the gas pipeline 2. The anti-rotation block 4 has a rectangular cross-section perpendicular to the axis of the gas pipeline to prevent the gas pipeline from rotating on its own during use.

[0018] The lifting hook 5 includes a lifting rod, a first hook body 3 fixed to the upper end of the lifting rod, and a second hook body 6 fixed to the lower end of the lifting rod. The width of the second hook body is adapted to the cross-sectional width of the anti-rotation block perpendicular to the axis of the gas pipeline. During installation, the anti-rotation block is engaged in the lower hook body, and the side wall of the lower hook body blocks the rotation of the anti-rotation block, thereby preventing the gas pipeline from rotating. The lifting hook provides a support point for the gas pipeline, facilitating operation of the pipeline by workers. The lifting hook in this embodiment is integrally bent and formed, making it very convenient to manufacture.

[0019] In this embodiment, the gas supply pipe and the argon sealing ring are integrally bent using an oxygen blowing pipe with a diameter of 8mm. The gas supply pipe 2 passes through the anti-rotation block 4 along the axial direction. The anti-rotation block 4 has a through hole that matches the outer diameter of the gas supply pipe. The gas supply pipe 2 is welded and fixed to the anti-rotation block 4.

[0020] The plane containing the first hook 3 is perpendicular to the plane containing the second hook 6. The opening width of the first hook is adapted to the horizontal axis of the outer shell of the intermediate package. The vertical projection of the first hook is located on the side of the vertical projection of the second hook that is closer to the argon sealing ring.

[0021] In continuous casting equipment, a separate external submersible nozzle is installed below the tundish nozzle. During continuous casting, argon gas is delivered to the argon sealing ring via a metal hose and gas supply pipe, and then ejected downwards from the argon sealing ring through the blast nozzle, forming an argon gas isolation layer around the connection area between the tundish nozzle and the external submersible nozzle. This isolation layer effectively prevents air from entering the molten steel pouring channel, avoiding reactions between the molten steel and oxygen, nitrogen, and other gases in the air, thereby reducing secondary oxidation and improving the protection level of continuous casting.

[0022] By using the device described in this embodiment to improve the continuous casting protective pouring level, the degree of secondary oxidation of molten steel is significantly reduced, with the total oxygen content of the steel decreasing by 3 ppm and the nitrogen content decreasing by 10 ppm, effectively improving the internal quality of the steel; the inclusion levels for each series are ≤1.5, meeting the high requirements for steel purity. Furthermore, it reduces the generation of scrap billets, decreasing scrap billet production by 2.5 tons per pour, while saving processing costs of 0.75 yuan / ton. From both the reduction of scrap billets and the saving of processing costs, production costs are further reduced.

[0023] Of course, the above description is not limited to the examples above. Technical features of this utility model not described can be implemented by or using existing technology, and will not be repeated here. The above embodiments and drawings are only used to illustrate the technical solution of this utility model and are not intended to limit this utility model. This utility model has been described in detail with reference to preferred embodiments. Those skilled in the art should understand that any changes, modifications, additions or substitutions made by those skilled in the art within the scope of this utility model do not depart from the spirit of this utility model and should also fall within the protection scope of the claims of this utility model.

Claims

1. A device for improving the protective pouring level in continuous casting, characterized in that: It includes an argon sealing ring (1) fitted at the lower end of the water inlet of the middle package, and a gas supply pipe (2) fixed to one end of the argon sealing ring. The inner cavity of the argon sealing ring (1) is connected to the gas supply pipe (2). The other end of the argon sealing ring is sealed. Several jet holes (7) are opened on the bottom surface of the argon sealing ring (1). Each jet hole (7) is arranged in sequence along the circumference, and the range of gas ejected from each jet hole is closed along the circumference.

2. The device for improving the protective pouring level in continuous casting according to claim 1, characterized in that: It also includes a hook (5) and an anti-rotation block (4) fixed to the gas pipeline (2), wherein the anti-rotation block (4) has a rectangular cross section perpendicular to the axis of the gas pipeline; The hook (5) includes a rod, a first hook (3) fixed at the upper end of the rod, and a second hook (6) fixed at the lower end of the rod. The width of the second hook is adapted to the cross-sectional width of the anti-rotation block perpendicular to the axis of the gas pipeline.

3. The device for improving the protective pouring level in continuous casting according to claim 2, characterized in that: The gas pipe (2) passes through the anti-rotation block (4) along the axial direction. The anti-rotation block (4) has a through hole that matches the outer diameter of the gas pipe. The gas pipe (2) is welded and fixed to the anti-rotation block (4).

4. The device for improving the protective pouring level in continuous casting according to claim 2, characterized in that: The plane where the first hook (3) is located is perpendicular to the plane where the second hook (6) is located, and the opening width of the first hook is adapted to the horizontal axis of the outer shell of the intermediate package.

5. The device for improving the protective pouring level in continuous casting according to claim 2, characterized in that: The vertical projection of the first hook is located on the side of the vertical projection of the second hook that is closer to the argon sealing ring.

6. The device for improving the protective pouring level in continuous casting according to claim 1, characterized in that: The gas pipeline and the argon sealing ring are bent into one piece, and the end of the gas pipeline away from the argon sealing ring is connected to a metal hose.

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