Molten steel rotational flow controller for continuous casting tundish

Abstract

The invention relates to the technical field of continuous casting tundishes, in particular to a molten steel rotational flow controller for a continuous casting tundish. The shell is cylindrical, and a hollow cavity is formed in the shell; the top face is open, the center area of the opening is used for containing injection flow, and the edge area of the opening is used for molten steel to flow out. A rotational flow guide cone is arranged in the center of the bottom surface of the cavity and is of a cone structure, and the upper surface of the rotational flow guide cone is turbine-shaped; and the inner wall of the cavity is parabola-shaped. And the liquid level fluctuation and the flow field can be fundamentally controlled, so that the quality of the continuous casting billet is improved.

Description

Technical Field

[0001] The invention relates to the technical field of continuous casting tundish, in particular to a molten steel swirl controller for a continuous casting tundish. Background Art

[0002] During the continuous casting of molten steel, the molten steel in the steel tank has a very high potential energy compared to the tundish. After entering the tundish, the potential energy is converted into huge kinetic energy, which causes the liquid level in the tundish to fluctuate violently, causing the molten steel to absorb oxygen. At the same time, it also causes the flow field and temperature field in the tundish to be unstable and difficult to control, which in turn leads to the deterioration of the quality of the continuous casting billet.

[0003] At present, a turbulence controller is usually used to control the initial flow field of the molten steel in the molten steel tank when it enters the tundish. However, the existing turbulence controllers have limited effects and poor control over the flow field of the molten steel. Chinese patent publication number CN202779664 discloses "a turbulence controller", and Chinese patent publication number CN2873365Y discloses "a turbulence controller". The above patents have at least the following defects and deficiencies: the speed of the molten steel flow flowing out of the turbulence controller is still relatively large, and the flow direction is close to vertically upward, making it difficult to achieve the purpose of fundamentally controlling the liquid level fluctuation and the flow field. Both have poor effects and are not worth promoting on a large scale. Summary of the invention

[0004] In order to overcome the deficiencies of the prior art, the present invention provides a swirling flow controller for molten steel in a continuous casting tundish, which can fundamentally control the liquid level fluctuation and flow field, thereby improving the quality of the continuous casting billet.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A molten steel swirl controller for a continuous casting tundish is cylindrical with a hollow cavity inside; the top surface is open, the central area of ​​the opening is used to receive injection, and the edge area of ​​the opening is used for the molten steel to flow out; a swirl guide cone is provided at the center of the bottom surface of the cavity, the swirl guide cone is a cone structure, and the upper surface is turbine-shaped; the inner wall of the cavity is parabolic.

[0007] Furthermore, the controller has a height of 100 to 600 mm.

[0008] Furthermore, the diameter of the controller is 200-900 mm.

[0009] Furthermore, the wall thickness of the controller is 10 to 150 mm.

[0010] Furthermore, the diameter of the opening is 160-800 mm.

[0011] Furthermore, the apex angle of the swirl guide cone is 30 to 170 degrees.

[0012] Furthermore, the cone height of the swirl guide cone is 10 to 500 mm.

[0013] Furthermore, the controller is built on the bottom of the tundish, and the opening is located directly below the long water inlet of the molten steel tank.

[0014] Compared with the prior art, the present invention has at least the following technical effects or advantages:

[0015] During the pouring process, the injection flow from the long nozzle of the molten steel tank is guided by the swirl guide cone, and spirally rotates around the cone and along the parabolic inner wall in the cavity, and finally flows out of the flow controller, and its flow direction is spiral upward. The role of the swirl guide cone and the inner wall of the parabolic cavity is to reduce the turbulence in the flow controller and make the molten steel flow out of the flow controller in a spiral upward direction. The axis of the spiral direction is the axis of the flow controller. In this way, the molten steel flowing out of the flow controller hits the liquid surface of the tundish at a large inclination angle, so the impact on the liquid surface is significantly reduced, and the flow and residence time of the molten steel between the two dams in the tundish are significantly prolonged, thereby achieving the function of controlling the flow field.

[0016] Because the impact of the molten steel flow on the liquid surface is significantly reduced, and the flow and residence time of the molten steel between the two dams in the tundish are significantly prolonged, the flow rate of the molten steel flow from this area (between the two dams) to the dam and the weir is also significantly reduced. The above conditions will reduce the dead zone area of ​​the flow field in the tundish, so the uniformity of the molten steel temperature in the tundish is greatly improved, and the probability of inclusions floating up will be significantly increased, thereby improving the quality of the continuous casting billet.

[0017] In conclusion, the present invention can conveniently and effectively control the flow field of molten steel in the tundish, reduce the exposure of the tundish liquid surface, improve the flow field of the tundish, improve the uniformity of the composition and temperature of the molten steel flowing into the crystallizer, and improve the quality of the continuous casting billet. Moreover, the present invention is easy to operate, maintain, and has a low cost of use. The structure is simple, the investment is small, and it is conducive to promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic front cross-sectional view of the structure of the present invention.

[0019] Figure 2 It is a schematic top view of the structure of the present invention.

[0020] Figure 3 It is a schematic diagram of the working state of the present invention.

[0021] In the figure: 1- flow controller 2- swirl guide cone 3- molten steel flow 4- covering agent 5- long water inlet of molten steel tank 6- dam 7- weir 8- inner wall of cavity DETAILED DESCRIPTION

[0022] The embodiments of the present invention are described in detail below. In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described in combination with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0024] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] In the description of the present invention, it should be noted that the terms used herein are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0026] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, the numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0027] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0028] like Figure 1 , Figure 2 As shown, a swirling flow controller 1 for molten steel for a continuous casting tundish is cylindrical with a hollow cavity inside; the top surface is open, the central area of ​​the opening is used to receive the injection, and the edge area of ​​the opening is used for the molten steel to flow out; a swirling flow guide cone 2 is provided at the center of the bottom surface of the cavity, the swirling flow guide cone 2 is a cone structure, and the upper surface is turbine-shaped; the inner wall 8 of the cavity is parabolic.

[0029] The height of the controller 1 is 100-600 mm. The diameter of the controller 1 is 200-900 mm. The wall thickness of the controller 1 is 10-150 mm. The diameter of the opening is 160-800 mm. The cone vertex angle of the swirl guide cone 2 is 30-170°, and the cone height of the swirl guide cone 2 is 10-500 mm.

[0030] The controller 1 is built at the bottom of the tundish, and its opening is located just below the long water inlet 5 of the molten steel ladle.

[0031] like Figure 3 As shown, the working principle and working process of the present invention are as follows:

[0032] 1. Prepare a flow controller 1, build it on the bottom of the tundish, bake the tundish, and provide a covering agent 4 above the flow controller 1.

[0033] 2. When continuous casting begins, the injection flow from the long nozzle 5 of the molten steel tank is guided by the swirl guide cone 2, and spirally rotates around the cone and along the parabolic cavity inner wall 8 in the cavity of the flow controller, and finally flows out of the flow controller 1, and its flow direction is spiral upward. The swirl guide cone 2 and the parabolic cavity inner wall 8 both reduce the turbulence in the flow controller and make the molten steel flow out of the flow controller 1 in a spiral upward direction, and the axis of the spiral direction is the axis of the flow controller.

[0034] 3. The molten steel flow 3 flowing out of the flow controller 1 impacts the liquid surface of the tundish at a relatively large inclination angle, thereby significantly reducing the impact on the liquid surface and significantly prolonging the flow path and residence time of the molten steel between the two dams 6 in the tundish, thereby achieving the function of controlling the flow field.

[0035] 4. Because the impact of the molten steel flow 3 on the liquid surface is significantly reduced, and the flow and residence time of the molten steel between the two dams 6 in the tundish are significantly prolonged, the flow rate of the molten steel flow flowing out of this area (between the two dams) to the dam 6 and the weir 7 will also be significantly reduced. The above conditions will reduce the dead zone area of ​​the flow field in the tundish, so the uniformity of the molten steel temperature in the tundish is greatly improved, and the probability of inclusions floating up will also be significantly increased, thereby improving the quality of the continuous casting billet.

[0036] The present invention can conveniently and effectively control the flow field of molten steel in the tundish, reduce the exposure of the tundish liquid surface, improve the flow field of the tundish, improve the uniformity of the composition and temperature of the molten steel flowing into the crystallizer, and improve the quality of the continuous casting billet. It is also easy to operate, easy to maintain, and has low use cost. It has a simple structure, low investment, and is conducive to promotion.

[0037] Embodiment 1:

[0038] A molten steel swirl controller 1 for a continuous casting tundish is used for tundish flow control processing of a one-machine two-stream slab continuous casting machine for continuously casting ship plate steel.

[0039] The preparation method, working principle, usage method, working process and technical effect data are as follows:

[0040] 1. Prepare a flow controller 1, the height of the flow controller is 230 mm, the outer diameter is 500 mm, the wall thickness is 40 mm, the opening diameter is 400 mm, the cone top angle of the swirl guide cone 2 is 120°, and the cone height of the swirl guide cone 2 is 200 mm.

[0041] 2. Build the flow controller 1 at the bottom of the tundish.

[0042] 3. Bake the middle bag.

[0043] 4. When continuous casting begins, the injection flow from the long nozzle 5 of the molten steel tank is guided by the swirl guide cone 2, and spirally rotates around the cone and along the parabolic cavity inner wall 8 in the cavity of the flow controller, and finally flows out of the flow controller 1, and its flow direction is spiral upward. The functions of the swirl guide cone 2 and the parabolic cavity inner wall 8 are to reduce the turbulence in the flow controller and make the molten steel flow out of the flow controller in a spiral upward direction, and the axis of the spiral direction is the axis of the flow controller.

[0044] 5. The molten steel flow 3 flowing out of the flow controller 1 impacts the liquid surface of the tundish at a relatively large inclination angle, thereby significantly reducing the impact on the liquid surface and significantly prolonging the flow path and residence time of the molten steel between the two dams 6 in the tundish, thereby achieving the function of controlling the flow field.

[0045] 6. After testing the ingot, the surface defect rate of the ingot was reduced from 3.5% to 2.6%. As an indicator of the inclusion content, the total oxygen content was reduced from 0.0025% to 0.0019%.

[0046] Embodiment 2:

[0047] A molten steel swirl controller 1 for a continuous casting tundish is used for tundish flow control processing of continuous casting of plain carbon steel Q235B by a one-machine two-stream slab continuous casting machine.

[0048] The preparation method, working principle, usage method, working process and technical effect data are as follows:

[0049] 1. Prepare a flow controller 1, the external height of the flow controller is 210 mm, the external diameter is 480 mm, the wall thickness is 30 mm, the diameter of the opening is 410 mm, the cone apex angle is 100°, and the cone height is 190 mm.

[0050] 2. Build the flow controller 1 at the bottom of the tundish.

[0051] 3. Bake the middle bag.

[0052] 4. When continuous casting begins, the injection flow from the long nozzle 5 of the molten steel tank is guided by the swirl guide cone 2, and spirally rotates around the cone and along the parabolic cavity inner wall 8 in the cavity of the flow controller, and finally flows out of the flow controller, and its flow direction is spiral upward. The swirl guide cone 2 and the parabolic cavity inner wall 8 both reduce the turbulence in the flow controller and make the molten steel flow out of the flow controller in a spiral upward direction, and the axis of the spiral direction is the axis of the flow controller.

[0053] 5. The molten steel flowing out of the flow controller 1 impacts the liquid surface of the tundish at a relatively large inclination angle, thereby significantly reducing the impact on the liquid surface and significantly prolonging the flow path and residence time of the molten steel between the two dams 6 in the tundish, thereby achieving the function of controlling the flow field.

[0054] 6. After testing the ingot, the surface defect rate of the ingot was reduced from 3.8% to 2.6%. As an indicator of the inclusion content, the total oxygen content was reduced from 0.0029% to 0.0021%.

[0055] The present invention can fundamentally control the liquid level fluctuation and the flow field, thereby improving the quality of the continuous casting billet.

[0056] The protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent substitutions or changes according to the technical solution and inventive concept of the present invention within the technical scope disclosed by the present invention, and all of them should be covered by the protection scope of the present invention.

Claims

1. A molten steel swirl controller for a continuous casting tundish, characterized in that: It is cylindrical in shape, with a hollow cavity inside; The top surface is open, the central area of ​​the opening is used to receive the injection flow, and the edge area of ​​the opening is used for the molten steel to flow out; A swirl guide cone is provided at the center of the bottom surface of the cavity. The swirl guide cone is a cone structure, and the upper surface is turbine-shaped. The inner wall of the cavity is parabolic.

2. A swirling flow controller for molten steel in a continuous casting tundish according to claim 1, characterized in that: The controller height is 100~600mm.

3. The swirl controller for molten steel in a continuous casting tundish according to claim 1, characterized in that: The controller has a diameter of 200-900 mm.

4. The swirl controller for molten steel in a continuous casting tundish according to claim 1, characterized in that: The wall thickness of the controller is 10-150 mm.

5. The swirl controller for molten steel in a continuous casting tundish according to claim 1, characterized in that: The diameter of the opening is 160-800 mm.

6. The swirl controller for molten steel in a continuous casting tundish according to claim 1, characterized in that: The apex angle of the swirl guide cone is 30-170°.

7. The swirl controller for molten steel in a continuous casting tundish according to claim 1, characterized in that: The cone height of the swirl guide cone is 10-500 mm.

8. The swirl controller for molten steel in a continuous casting tundish according to claim 1, characterized in that: The controller is built on the bottom of the tundish, and its opening is located just below the long water inlet of the molten steel tank.

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