Air curtain device for improving purity of molten steel in continuous casting tundish

Abstract

The utility model discloses an air curtain device for improving the purity of molten steel in a continuous casting tundish, which comprises the tundish, a turbulence controller arranged in the tundish, a retaining wall arranged in the tundish and positioned on one side of the turbulence controller, an impact area arranged on one side in the tundish, a stopper rod area arranged at one end of the tundish, and a stopper rod arranged in the stopper rod area and used for flowing the molten steel, an air curtain assembly is arranged in the tundish, argon is blown into the two sets of air pipes through air pipe connectors, so that the blown-out air forms an air blocking wall in the tundish, molten steel flowing out of a stopper rod in an impact area passes through the blocking wall, and inclusions of 0-10 micrometers move upwards under the action of floating force turning under the flowing of the air and finally move to the steel surface; and as the gas is blown out from the bottom, an upward force can be generated to push the inclusions upwards and finally discharge the inclusions out of the molten steel, so that the inclusions cannot be brought into a crystallizer in the molten steel to be solidified and enter a steel billet, and the aim of improving the purity of the molten steel is fulfilled.

Description

Technical Field

[0001] The utility model belongs to the technical field of continuous casting tundishes in iron and steel metallurgy, and in particular relates to an air curtain device for improving the purity of molten steel in the continuous casting tundish. Background Art

[0002] As the market's demand for stainless steel quality continues to improve, downstream high-end customers require higher product quality, first of all, the purity of the molten steel. The thickness has been reduced from a few millimeters to a few tenths of a millimeter, and then to the current hand-torn stainless steel, which is thinner than the thickness of a piece of paper. The previous inclusions were 20-30μm or even more, but now the inclusions need to be controlled below 5-10μm, and the high-melting-point magnesium-aluminum spinel inclusions need to be removed to improve the purity of the molten steel. The existing continuous casting tundish, as the last checkpoint in steelmaking pouring, needs to further purify the molten steel and remove fine inclusions in the molten steel, especially inclusions around 15μm.

[0003] However, in actual production, the content of inclusion elements and non-metallic inclusions in the clean molten steel after refining treatment, which enters the billet pulled out of the continuous casting machine through the tundish and crystallizer, still increases to varying degrees, and the final cleanliness of the molten steel does not reach the ideal goal. Therefore, various flow control devices such as retaining walls, turbulence controllers, and porous filters are set in the tundish to change the flow state of the molten steel, extend the residence time of the molten steel in the tundish, and promote the floating of non-metallic inclusions in the molten steel. However, a large number of studies have shown that the setting of flow control technologies such as retaining walls is only effective for the removal of inclusions larger than 50μm, and the removal effect on tiny inclusions (less than 50μm) is not obvious, and secondary pollution of the molten steel is caused by erosion and corrosion. Utility Model Content

[0004] The utility model aims to provide a gas curtain device for improving the purity of molten steel in a continuous casting tundish, so as to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the utility model provides the following technical solution: an air curtain device for improving the purity of molten steel in a continuous casting tundish, comprising:

[0006] A tundish, wherein a turbulence controller is provided in the tundish, a retaining wall is provided in the tundish and on one side of the turbulence controller, an impact zone is provided in one side of the tundish, a stopper rod zone is provided at one end of the tundish and a stopper rod for flowing molten steel is provided in the stopper rod zone, a gas curtain assembly for forming a gas curtain to float inclusions in the molten steel is provided in the tundish and on one side of the turbulence controller, argon is pumped into the gas pipe through a breathable argon blowing machine of the gas curtain assembly, so that the argon gas is blown out through a plurality of gas outlets on the surface of the gas pipe, forming a gas curtain to float inclusions in the molten steel.

[0007] Preferably, the air curtain assembly comprises a protective shell and an air pipe joint, the protective shell is arranged in the bottom of the tundish, two groups of air pipes are provided and both are arranged in the protective shell, and the air pipe joint is connected to the two groups of air pipes.

[0008] Preferably, one end of the breathable argon blowing machine is connected to the air pipe joint through a pipeline.

[0009] Preferably, a retaining dam is provided in the tundish and located on one side of the retaining wall.

[0010] Compared with the prior art, the utility model has the following beneficial effects: by installing the gas curtain assembly in the bottom of the tundish, parallel to the working layer, and using inert gas argon as the medium, the argon reacts with other elements of the molten steel, and the external argon pipeline is blown into the gas pipe joint through the gas permeable argon blowing machine, and then blown into the two groups of gas pipes through the gas pipe joint, and blown out through the gas outlet holes on the surface of the gas pipe, so that the blown gas forms a gas wall in the tundish, and the molten steel flowing out of the stopper rod in the impact zone passes through the wall, and due to the flow of gas, the 0-10μm inclusions in the molten steel pass through and collide with the gas wall, and the steel The density of the liquid is greater than that of the inclusions. Inclusions of 0-10μm move upward under the action of the buoyancy of the gas flow, and finally move to the steel surface, so that inclusions below 10μm can be floated up through the air curtain formed by the air curtain assembly at the bottom of the tundish, and multiple small inclusions are repeatedly collided to form an inclusion larger than 20μm. Since the gas is blown out at the bottom, it will also generate an upward force, pushing the inclusions upward, and finally expelling them from the molten steel, so that the inclusions will not be brought into the crystallizer in the molten steel to solidify into the billet, thereby achieving the purpose of improving the purity of the molten steel. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural schematic diagram of the utility model;

[0012] Figure 2 It is a top view of the protective shell of the utility model.

[0013] In the figure: 1. Tundish; 2. Turbulence controller; 3. Retaining wall; 4. Impact zone; 5. Stopper rod zone; 6. Stopper rod; 7. Gas curtain assembly; 8. Breathable argon blower; 9. Gas pipe; 10. Gas outlet; 11. Protective shell; 12. Gas pipe joint; 13. Dam. DETAILED DESCRIPTION

[0014] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0015] The utility model provides Figure 1-2 The gas curtain device shown in the figure improves the purity of molten steel in a continuous casting tundish, comprising:

[0016] A tundish 1 is provided with a turbulence controller 2 in the tundish 1. The turbulence controller 2 is used to buffer the molten steel flowing out of the stopper rod 6 to prevent the molten steel surface near the stopper rod area 5 from turning over and exposing the liquid surface, thereby reducing slag rolling and secondary oxidation caused by the exposed liquid surface. A retaining wall 3 is provided in the tundish 1 and located on one side of the turbulence controller 2. An impact zone 4 is provided on one side of the tundish 1. A stopper rod area 5 is provided at one end of the tundish 1 and a stopper rod 6 for flowing the molten steel is provided in the stopper rod area 5. A gas curtain assembly 7 for forming a gas curtain to float the inclusions in the molten steel is provided in the tundish 1 and located on one side of the turbulence controller 2. Argon is pumped into the air pipe 9 through a breathable argon blowing machine 8 of the gas curtain assembly 7, so that the argon is blown out through a plurality of gas outlets 10 on the surface of the air pipe 9 to form a gas curtain to float the inclusions in the molten steel.

[0017] The gas curtain assembly 7 includes a protective shell 11 and an air pipe joint 12. The protective shell 11 is arranged at the bottom of the tundish 1. Two groups of air pipes 9 are provided and both are arranged in the protective shell 11. The air pipe joint 12 is connected to the two groups of air pipes 9. The argon gas blown out from the two groups of air pipes 9 through the surfaces of the two groups of air pipes 9 can form an air curtain.

[0018] One end of the air-permeable argon blowing machine 8 is connected to the air pipe joint 12 through a pipeline.

[0019] A dam 13 is provided in the tundish 1 and on one side of the retaining wall 3, which limits the fluctuation of the injected molten steel to the upstream of the retaining wall 3 and the dam 13, stabilizes the working liquid level of the molten pool of the downstream tundish 1, and is beneficial to reducing the amount of inclusions caused by surface slag, secondary oxidation and mechanical scouring.

[0020] The gas curtain device for improving the purity of molten steel in the continuous casting tundish is characterized in that the gas curtain assembly 7 is installed in the bottom of the tundish 1 in parallel with the working layer, and inert gas argon is used as a medium. Argon reacts with other elements in the molten steel. The external argon pipeline is blown into the joint of the gas pipe 9 through a breathable argon blowing machine 8, and then blown into two groups of gas pipes 9 through the gas pipe 9 joint, and then blown out through the gas outlet 10 on the surface of the gas pipe 9, so that the blown gas forms a gas wall in the tundish 1, and the molten steel flowing out of the stopper rod 6 in the impact zone 4 passes through the wall. Due to the flow of gas, inclusions of 0-10 μm in the molten steel pass through and collide with the gas wall. The density of the molten steel is greater than that of the inclusions. The inclusions of 0-10μm move upward under the action of the buoyancy of the gas flow, and finally move to the steel surface, so that the inclusions below 10μm can be floated by the air curtain formed by the air curtain assembly 7 at the bottom of the tundish 1. Multiple fine inclusions are repeatedly collided to form an inclusion larger than 20μm. Since the gas is blown out at the bottom, it will also generate an upward force to push the inclusions upward and finally exclude them from the molten steel, so that the inclusions will not be brought into the crystallizer in the molten steel to solidify into the billet, thereby achieving the purpose of improving the purity of the molten steel.

[0021] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An air curtain device for improving the purity of molten steel in a continuous casting tundish, characterized in that: include: A tundish (1) is provided with a turbulence controller (2) in the tundish (1), a retaining wall (3) is provided in the tundish (1) and located on one side of the turbulence controller (2), an impact zone (4) is provided in one side of the tundish (1), a stopper zone (5) is provided at one end of the tundish (1), and a stopper (6) for flowing molten steel is provided in the stopper zone (5), a gas curtain assembly (7) for forming a gas curtain to float inclusions in the molten steel is provided in the tundish (1) and located on one side of the turbulence controller (2), argon gas is pumped into a gas pipe (9) through a gas-permeable argon blowing machine (8) of the gas curtain assembly (7), so that the argon gas is blown out through a plurality of gas outlets (10) on the surface of the gas pipe (9), thereby forming a gas curtain to float inclusions in the molten steel.

2. The gas curtain device for improving the purity of molten steel in a continuous casting tundish according to claim 1, characterized in that: The air curtain assembly (7) comprises a protective shell (11) and an air pipe joint (12); the protective shell (11) is arranged in the bottom of the tundish (1); two groups of air pipes (9) are provided and both are arranged in the protective shell (11); and the air pipe joint (12) is connected to the two groups of air pipes (9).

3. The gas curtain device for improving the purity of molten steel in the continuous casting tundish according to claim 2, characterized in that: One end of the air-permeable argon blowing machine (8) is connected to the air pipe joint (12) through a pipeline.

4. The gas curtain device for improving the purity of molten steel in a continuous casting tundish according to claim 1, characterized in that: A retaining dam (13) is provided in the tundish (1) and located on one side of the retaining wall (3).

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