Multi-channel turbulence controller and continuous casting tundish
By designing a multi-channel turbulence controller, the molten steel stream is broken down into multiple fine streams, which solves the problems of slag holes and secondary oxidation caused by the backflow impact of molten steel, and improves the cleanliness of the billet and the stability of production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NORTHEASTERN UNIV CHINA
- Filing Date
- 2026-05-27
- Publication Date
- 2026-06-30
AI Technical Summary
Existing single-channel turbulence controllers cannot effectively suppress the vertical upward backflow impact of molten steel, resulting in technical problems such as slag holes, slag entrapment, and secondary oxidation found in existing technologies.
By adopting a multi-channel structural design, the molten steel stream is broken down into multiple small streams. Through multi-channel diversion, speed reduction and energy dissipation, and mutual interference of streams, the molten steel backflow velocity is significantly reduced, and slag hole formation is suppressed.
It effectively inhibits slag formation, reduces secondary oxidation and slag entrapment in molten steel, improves billet cleanliness and continuous casting production stability, improves molten steel temperature distribution, and reduces the risk of nozzle blockage.
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Figure CN122298970A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of clean steel smelting technology, and specifically to a multi-channel turbulence controller and a continuous casting tundish. Background Technology
[0002] In continuous casting, the tundish, as a key reaction vessel in the continuous casting process, is mainly used to receive the molten steel injected from the ladle and stably distribute it to each crystallizer. The tundish can transform the molten steel supplied by intermittent smelting into a continuous and stable casting stream, achieving precise control of the temperature and cleanliness of the molten steel. It is the core hub connecting the intermittent smelting and continuous casting processes.
[0003] In actual continuous casting production, ladles need to be replaced periodically, resulting in periodic shutdowns of casting. To ensure a constant casting speed, molten steel continues to be injected into the crystallizer from the tundish during the ladle shutdown, causing the tundish liquid level to drop continuously. After the ladle replacement is completed and casting resumes, the molten steel injection velocity needs to be significantly increased to quickly raise the molten steel level in the tundish to a steady-state casting level. However, at this time, the tundish is in a non-steady-state liquid level condition. Due to the low liquid level and high injection velocity, the molten steel flows directly from the long nozzle and impacts the bottom of the tundish, forming a high-speed, vertically upward reflux stream. This reflux stream directly impacts the slag-metal interface within the tundish, disrupting the original slag-metal interface balance, causing localized tearing of the protective slag layer and large-area exposure of the molten steel, thus forming a "slag eye" phenomenon. The appearance of slag eyes signifies the failure of the tundish metallurgical barrier, which can trigger a series of systemic and serious hazards: (1) It causes serious secondary oxidation and inclusion proliferation. When exposed molten steel comes into contact with air, the oxygen and nitrogen content increases sharply. Excess oxygen combines with dissolved Al in the molten steel to form endogenous inclusions. (2) It causes slag inclusion and macroscopic inclusion defects. The slag droplets are drawn into the interior of the molten steel, making it difficult to float and remaining in the billet; (3) It exacerbates the heat loss and temperature unevenness of molten steel. Exposed molten steel radiates heat and easily leads to local low temperature.
[0004] Existing turbulence controllers all have a single outlet structure. According to the law of mass conservation, the average velocity of the returning molten steel is determined by both the amount of steel poured and the outlet cross-sectional area. Traditional single-channel turbulence controllers cannot fundamentally reduce the vertically upward backflow impact, especially during unsteady pouring when changing ladles, where the impact is even more severe, and they cannot solve problems such as slag holes, slag entrapment, and secondary oxidation.
[0005] To address this, the present invention proposes a multi-channel turbulence controller device to overcome the shortcomings of existing technologies. Summary of the Invention
[0006] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a multi-channel turbulence controller device for continuous casting tundishes. This invention employs a multi-channel structure to divert and refine the molten steel flow. Under the same total flow rate, a single, large stream of molten steel is broken down into multiple smaller streams. These smaller streams have a larger contact area with the existing molten steel in the tundish pool, resulting in more thorough mixing and disturbance. This allows for rapid dissipation of the turbulent kinetic energy of the molten steel, achieving efficient deceleration and energy dissipation, and reducing mutual interference between streams. It significantly weakens the upward reflux energy of the molten steel, reduces the reflux velocity, and greatly reduces the direct impact of the molten steel on the slag-metal interface, inhibiting slag porosity at its source. It effectively reduces problems such as secondary oxidation of molten steel, slag entrapment, uneven temperature distribution of molten steel, and blockage of long nozzles, improving billet cleanliness and the stability of continuous casting production. It solves the shortcomings of existing conventional turbulence controllers that only limit flow and lack kinetic energy gradient dissipation, and cannot effectively suppress the impact of vertically upward molten steel backflow; it avoids the problem that large flow streams have strong impact force and large impact depth, which can easily break through the surface slag layer, causing molten steel to be exposed and forming slag holes, which in turn leads to a series of technical problems such as deterioration of molten steel composition, uneven molten steel temperature, and slag droplet entanglement.
[0007] (II) The technical solution of the present invention is as follows: In a first aspect, the present invention provides a multi-channel turbulence controller device, comprising a controller body (1) and a hollow chamber (2) formed therein. The controller body (1) is a cuboid or cylindrical structure, and its interior is a hollow cavity (2) of a cuboid or cylindrical shape; a square upper outlet (4) is provided at the geometric center of the upper surface of the controller body (1), and the upper outlet (4) is connected to the hollow cavity (2). The bottom area of the hollow inner cavity (2) is 38-45 times the cross-sectional area of the long nozzle; the internal height of the hollow inner cavity (2) is 1 / 5-3 / 5 of the height of the tundish inner cavity; the area of the upper outlet (4) is 7-9 times the cross-sectional area of the long nozzle. Around the upper outlet (4), with the upper outlet (4) as the center, there are vertical guide holes that penetrate the upper surface of the controller body (1) in a centrally symmetrical manner. The number of guide holes is 4-8. The guide holes include a first guide hole (31) and a second guide hole (32). The second guide hole (32) is located on the extension line of the diagonal of the upper outlet (4), and the first guide hole (31) is located on the extension line of the midline of any two opposite sides of the upper outlet (4). According to a preferred embodiment of the present invention, the controller body (1) is a cuboid structure, with its upper and lower surfaces being square walls and its four sides being rectangular walls, and its internal hollow cavity (2) being a cuboid cavity; the bottom area of the hollow cavity (2) is 42-45 times the cross-sectional area of the long nozzle; the internal height of the hollow cavity (2) is 1 / 5 of the height of the intermediate liner cavity; and the area of the upper outlet (4) is 8 times the cross-sectional area of the long nozzle.
[0008] According to a preferred embodiment of the present invention, the area of the first guide hole (31) is larger than that of the second guide hole (32); the area of the first guide hole (31) is 0.55-0.56 times the cross-sectional area of the long water inlet, and the area of the second guide hole (32) is 0.24-0.26 times the cross-sectional area of the long water inlet.
[0009] According to a preferred embodiment of the present invention, an edge portion (22) is formed on the upper surface of the controller body (1) between the upper outlet (4) and the outer edge of the controller body (1), and the guide hole is provided on the edge portion (22).
[0010] According to a preferred embodiment of the present invention, the number of the guiding holes is 8, including 4 first guiding holes (31) and 4 second guiding holes (32), wherein the second guiding holes (32) are located at the four vertices of the upper surface of the square; the first guiding holes (31) are located at the midpoint of the line connecting two adjacent second guiding holes (32).
[0011] According to a preferred embodiment of the present invention, the sum of the areas of all the guide holes accounts for 5%-10% of the upper surface area of the controller body (1), preferably 6.5%; the cross-sectional area of the upper outlet (4) accounts for 7-16% of the upper surface area of the controller body (1).
[0012] According to a preferred embodiment of the present invention, the distance from the second guide hole (32) to the edge of the upper surface of the controller body (1) is 0.1-0.12 of the side length of the upper surface; the distance from the first guide hole (31) to the edge of the upper surface of the controller body (1) is 0.08-0.1 of the side length of the upper surface.
[0013] According to a preferred embodiment of the present invention, the upper surface of the controller body (1) is a detachable cover plate, on which the upper outlet (4) and the guide hole are provided, and the specifications and / or the number of the upper outlet (4) and the guide hole provided on different cover plates are different to match the use of different casting stages.
[0014] Secondly, the present invention provides a continuous casting tundish, comprising: a multi-channel turbulence controller device of any of the above embodiments fixedly installed at the bottom of the tundish, directly below the long nozzle.
[0015] <III> Compared with the prior art, the present invention has at least the following technical effects: 1. Inhibit the formation of slag holes at the source and solve the problems of secondary oxidation and slag entrapment.
[0016] The turbulence controller of this invention adopts a multi-channel structure design. On the one hand, it significantly expands the molten steel return flow area, and based on the principle of mass conservation, significantly reduces the average return velocity of the vertically upward molten steel. On the other hand, it breaks down the original single, large, high-energy return stream into multiple fine streams. Under the same flow rate, the fine streams have a larger contact and mixing range with the molten steel in the tundish pool, and the mixing disturbance is more complete. This can quickly dissipate the turbulent kinetic energy of the molten steel itself, and further attenuate the return kinetic energy and weaken the impact energy with the help of fluid viscous friction. At the same time, the non-uniform size guide holes can balance the molten steel flow velocity in each area and avoid the phenomenon of local concentrated high-speed direct impact. In addition, the mutual disturbance and interference energy dissipation between multiple fine streams further weaken the vertical return kinetic energy and impact intensity, fundamentally reducing the severe impact of molten steel on the slag-metal interface, effectively inhibiting slag formation, and eliminating problems such as secondary oxidation and increased nitrogen and oxygen content in molten steel caused by exposure to air. At the same time, it avoids macroscopic inclusion defects caused by strong impact encapsulating slag layers, significantly improving the overall cleanliness of the billet.
[0017] 2. Optimize the flow state of molten steel and enhance the metallurgical effect of the tundish.
[0018] This invention retains the edge structure of the turbulence controller (baffle from the upper outlet to the edge), which enhances the mixing and back-mixing of molten steel within the controller and promotes the removal of inclusions. At the same time, through multi-channel diversion, the flow of molten steel in the tundish is made more uniform, improving the temperature distribution of molten steel, avoiding Al2O3 precipitation caused by excessively low local temperatures, reducing the risk of nozzle blockage, and ensuring smooth continuous casting production.
[0019] 3. Adapts to unsteady casting conditions, improving process stability.
[0020] For unsteady casting (low liquid level, high injection velocity) during ladle changeover, the multi-channel diversion design of this turbulence controller can effectively buffer the impact of high-speed injection, and stabilize the slag-gold interface even under ladle changeover conditions. This solves the problem of failure of traditional single-channel controllers under unsteady conditions and improves the stability and reliability of continuous casting process.
[0021] 4. Simple structure, easy to industrialize.
[0022] The overall structure of the turbulence controller is a cuboid, and the flow guide hole includes several vertically upward circular holes. It is easy to manufacture and does not require complex irregular structures. The dimensional parameters are clear and can be flexibly adjusted according to different tundish and long nozzle specifications. It is compatible with existing continuous casting production lines and does not require large-scale modification, making it easy to promote industrialization. Attached Figure Description
[0023] Figure 1 This is a schematic diagram of the three-dimensional structure of the multi-channel turbulence controller in Example 1.
[0024] Figure 2 This is a top view of the multi-channel turbulence controller in Example 1.
[0025] Figure 3 This is a schematic diagram showing the installation location of the multi-channel turbulence controller in the intermediate package, as described in Example 1.
[0026] Figure 4 This is a schematic diagram of the three-dimensional structure of the multi-channel turbulence controller in Example 2.
[0027] Marker explanation: 1-Controller body; 2-Hollow cavity; 21-Upper cover plate; 4-Upper outlet; 22-Edge; 31-First guide hole, 32-Second guide hole. Detailed Implementation
[0028] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.
[0029] Example 1 like Figure 1-2 The diagram shows a three-dimensional structural schematic and a top view of a multi-channel turbulence controller device. The multi-channel turbulence controller includes a controller body 1, which is a rectangular parallelepiped structure with square walls on its upper and lower surfaces and rectangular walls (without openings) on all four sides. Inside the controller body 1 is a hollow chamber 2, the shape of which is identical to that of the controller body 1. The area of the lower surface of the hollow chamber 2 is 38-45 times the cross-sectional area of the molten steel nozzle, preferably 42-45 times; the internal height of the hollow chamber 2 is 1 / 5-3 / 5 of the height of the tundish cavity, preferably 1 / 5.
[0030] A square upper outlet 4 is provided at the geometric center of the upper surface of the controller body 1. The area of the upper outlet 4 is 7-9 times the cross-sectional area of the long water inlet, preferably 8 times, and preferably occupies 7-16% of the upper surface area of the controller body 1. Figure 1 As shown, a margin 22 is formed between the upper outlet 4 and the outer edge of the controller body 1, thereby enhancing the mixing and back mixing of molten steel in the controller and promoting the removal of inclusions.
[0031] Around the upper outlet 4, vertical guide holes are arranged symmetrically around the upper outlet 4, penetrating the upper surface of the controller body 1. The number of guide holes is 4-8, and all guide holes extend vertically upwards from the interior of the hollow cavity 2 through the upper surface of the controller body 1. Depending on their location, the guide holes include a first guide hole 31 and a second guide hole 32. The second guide hole 32 is located on the extension of the diagonal of the square upper outlet 4, and the first guide hole 31 is located on the extension of the midline of the two opposite sides of the upper outlet 4.
[0032] The controller body 1 has eight guide holes, specifically four first guide holes 31 and four second guide holes 32. The second guide holes 32 are located at the four corners of the upper surface of the square, while the first guide holes 31 are located at the midpoint of the line connecting two adjacent second guide holes 32. The area of the first guide hole 31 is larger than that of the second guide hole 32. The area of the first guide hole 31 is 0.55-0.56 times the cross-sectional area of the long water inlet, and the area of the second guide hole 32 is 0.24-0.26 times the cross-sectional area of the long water inlet. On the upper surface of the controller body 1, the total area of the guide holes 3 accounts for 5%-10% of the upper surface area, preferably 6.5%.
[0033] The distance from the second guide hole 32 to the edge of the upper surface of the controller body 1 is 0.1-0.12 of the side length of the upper surface; the distance from the first guide hole 31 to the edge of the upper surface of the controller body 1 is 0.08-0.1 of the side length of the upper surface. The upper surface of the controller body 1 is a detachable cover plate, on which the upper outlet 4 and the guide hole are provided. The specifications and / or number of the upper outlet 4 and the guide hole provided on different cover plates are different to match the use of different casting stages.
[0034] like Figure 3 As shown, the turbulence controller is fixedly installed at the bottom of the tundish, directly below the long nozzle of the ladle. The upper opening 4 of the turbulence controller faces the long nozzle and is used to receive the molten steel, constrain the high-speed jet, and prevent the molten steel from directly impacting the bottom and surface of the tundish, thus reducing slag entrainment and secondary oxidation. After exiting the long nozzle, the molten steel enters the hollow chamber 2 of the multi-channel turbulence controller through the upper opening 4 of the turbulence controller. After flowing out through the first guide hole 31 and the second guide hole 32 on the upper surface of the controller body 1 and the upper opening 4, it flows upward and back towards the surface of the tundish. After being turned by the dam / weir, it enters the crystallizer through the upper nozzle (submersible nozzle) of the tundish.
[0035] In the prior art, most of the guide holes are set on the side of the controller body and have a certain tilt angle (such as the common 12-30 degree elevation angle). However, the guide holes of the turbulence controller of the present invention are all perpendicular to the upper surface (or bottom surface) of the turbulence controller body and are completely vertically opened through hole structures, connecting the hollow cavity 2. This guide hole structure can, on the one hand, increase the backflow area, reduce the overall backflow velocity, separate the backflow stream, and reduce the backflow intensity.
[0036] Furthermore, the fluid velocity at the second guide holes 32 located at the four corners of the turbulence controller of the present invention is much higher than that at the first guide holes 31 located away from the corners. Therefore, by relatively reducing the cross-sectional area of the second guide holes 32, the backflow velocity of the molten steel at this location can be suppressed, avoiding uneven flow field and impact on the slag-metal interface caused by excessively high local flow velocities. Since the area of the second guide holes at the four corners is small, backflow occurs at this location. The direction of the backflow converges from the four corners of the controller body 1 towards the center at a certain angle. The collisions or interference between the backflows can effectively cancel out energy, further reducing the vertical velocity of the backflow, thereby reducing the impact of the backflow on the slag-metal interface and suppressing slag porosity formation, etc.
[0037] The working principle of the multi-channel turbulence controller device of the present invention is as follows: This invention achieves stable control of molten steel flow through the synergistic effects of multi-channel diversion, speed reduction and energy dissipation, and mutual interference between flow streams. After the molten steel enters the controller body 1 through the tundish inlet and the upper opening 4, it is first diverted through multiple sets of vertically upward guiding holes, decomposing the concentrated, high-speed single-stream flow into multiple low-speed, low-flow streams, significantly reducing the vertically upward impact kinetic energy of the molten steel. Secondly, through the matching design of guiding holes with different cross-sectional areas, the molten steel diversion velocity at the four apex corners of the controller body is lower than that at the non-apex corners, avoiding uneven flow field caused by excessively high local flow velocities. Thirdly, the multiple streams form a mutually interfering and canceling flow state in the internal chamber of the controller, further consuming the remaining kinetic energy of the molten steel and reducing the vertically upward flow intensity. This process can effectively suppress the disturbance of the slag-metal interface caused by the fluctuation of the molten steel level during ladle change, avoid slag layer rupture and slag hole formation caused by the impact of the injection flow, reduce secondary oxidation of molten steel, slag entrapment, inclusion accumulation and nozzle blockage, stabilize the slag-metal interface in the tundish, improve the temperature uniformity and flow stability of molten steel, and improve the cleanliness of the billet and the smoothness of continuous casting production.
[0038] Example 2 In this embodiment, as Figure 4As shown, the controller body 1 is cylindrical in shape, with circular walls on its upper and lower surfaces. Inside the controller body 1 is a hollow chamber 2, the shape of which is identical to that of the controller body 1. A square upper outlet 4 is located at the geometric center of the upper surface of the controller body 1. The area of the upper outlet 4 is 7-9 times, preferably 8 times, the cross-sectional area of the long nozzle, and preferably occupies 7-16% of the upper surface area of the controller body 1. A margin 22 is formed between the upper outlet 4 and the outer edge of the controller body 1, thereby enhancing the mixing and back-mixing of the molten steel within the controller and promoting the removal of inclusions. Around the upper outlet 4, eight vertically penetrating flow holes are arranged symmetrically around the upper outlet 4, extending vertically upwards through the upper surface of the controller body 1. Depending on their location, the flow holes include a first flow hole 31 and a second flow hole 32. The second guide hole 32 is located on the extension line of the diagonal of the upper outlet 4 of the square, and the first guide hole 31 is located on the extension line of the midline of the two opposite sides of the upper outlet 4. The other structural features of this embodiment are the same as those in Embodiment 1.
[0039] Example 3 In this embodiment, the cross-sectional area of the long nozzle corresponding to the tundish is 0.0064m², and the inner height of the tundish cavity is 1000mm.
[0040] The turbulence controller in this embodiment has a rectangular parallelepiped structure. The upper and lower surfaces are square walls with a side length of 0.6m, and the surrounding area is rectangular. Inside the controller body 1 is a hollow chamber 2, the shape of which is identical to that of the controller body 1. The area of the lower surface of the hollow chamber 2 is 0.2752m²; the internal height of the hollow chamber 2 is 2 / 5 of the height of the intermediate cavity (i.e., 400mm). A square upper outlet 4 with an area of 0.0512m² is located at the geometric center of the upper surface of the controller body 1. The cross-sectional area of the upper outlet 4 accounts for 14.2% of the area of the upper surface of the controller body 1. An edge 22 is formed between the upper outlet 4 and the outer edge of the controller body 1.
[0041] The number of guide holes is 6. Specifically, the 8 guide holes include 4 first guide holes 31 and 4 second guide holes 32. The 4 second guide holes 32 are respectively located at the four vertices of the upper surface of the square, and the 4 first guide holes 31 are respectively located at the midpoint of the line connecting two adjacent second guide holes 32. The area of a single first guide hole 31 is 0.003584 m², and the area of a single second guide hole 32 is 0.0016 m².
[0042] On the upper surface of the controller body 1, the total area of the guide holes accounts for 5.76% of the upper surface area. The area of a single second guide hole 32 accounts for 0.44% of the upper surface area of the controller body 1, and the area of a single first guide hole 31 accounts for 1.0% of the upper surface area of the controller body 1. The distance from the second guide hole 32 to the edge of the upper surface of the controller body 1 is 66 mm; the distance from the first guide hole 31 to the edge of the upper surface of the controller body 1 is 54 mm.
[0043] The installation method and workflow of this embodiment are the same as those of Embodiment 1: The turbulence controller device is fixedly installed at the bottom of the tundish, directly below the long nozzle of the ladle, with the upper opening 4 facing the long nozzle to receive the molten steel. The flow pattern of the molten steel after being injected into the tundish from the long nozzle is as follows: After exiting the long nozzle, the molten steel enters the hollow chamber 2 through the upper opening 4, flows out through the first guide hole 31, the second guide hole 32 and the upper opening 4, and then flows upward back towards the liquid surface of the tundish. After being turned by the dam / weir, it enters the crystallizer.
[0044] This embodiment, through fixed parameter design, is adapted to medium-speed casting scenarios. The reasonable layout and area matching of the eight guiding holes not only ensure the steel flow diversion and speed reduction effect, but also take into account the flow field uniformity, effectively suppress slag-metal interface disturbance, reduce slag entrapment and secondary oxidation, and improve the cleanliness of the cast billet.
[0045] Example 4 In this embodiment, the cross-sectional area of the long nozzle corresponding to the tundish is 0.01m², and the height of the tundish cavity is 1000mm. The controller body 1 is a rectangular parallelepiped structure with square walls on its upper and lower surfaces (the upper surface has a side length of 750mm) and rectangular walls on all sides. Inside the controller body 1 is a hollow cavity 2, and the shape of the hollow cavity 2 is consistent with that of the controller body 1.
[0046] The lower surface area of the hollow chamber 2 is 0.45 m²; the internal height of the hollow chamber 2 is 400 mm. The area of the upper outlet 4 is 0.08 m², and the cross-sectional area of the upper outlet 4 accounts for 14.2% of the upper surface area of the controller body 1. A flange 22 is formed between the upper outlet 4 and the outer edge of the controller body 1 to enhance the mixing and back mixing of molten steel within the controller.
[0047] Around the upper outlet 4, with the upper outlet 4 as the center, six vertically penetrating the upper surface of the controller body 1 are arranged symmetrically. All the guiding holes extend vertically upward from inside the hollow cavity 2 through the upper surface of the controller body 1. Specifically, the seven guiding holes include four first guiding holes 31 and three second guiding holes 32. The three second guiding holes 32 are respectively located at the two opposite corners of the upper surface of the square, and the four first guiding holes 31 are respectively located on the extension lines of the midlines of the two opposite sides of the upper outlet 4. The area of the first guiding hole 31 is 0.0056 m², and the area of the second guiding hole 32 is 0.0026 m². On the upper surface of the controller body 1, the total area of the guiding holes accounts for 5.37% of the upper surface area. The area of a single second guiding hole 32 accounts for 0.46% of the upper surface area of the controller body 1, and the area of a single first guiding hole 31 accounts for 1.0% of the upper surface area of the controller body 1. The distance from the second guide hole 32 to the edge of the upper surface of the controller body 1 is 90mm; the distance from the first guide hole 31 to the edge of the upper surface of the controller body 1 is 75mm. The installation method and workflow of this embodiment are the same as those of embodiment 1: the turbulence controller device is fixedly installed at the bottom of the tundish, directly below the long nozzle of the ladle, and the upper opening 4 is directly opposite the long nozzle to receive the molten steel; after the molten steel comes out from the long nozzle, it enters the hollow chamber 2 through the upper opening 4, flows out through the first guide hole 31, the second guide hole 32 and the upper opening 4 and then flows upward back, rushing towards the liquid surface of the tundish, and enters the crystallizer after being turned by the dam / weir.
[0048] This embodiment, through fixed parameter design, is adapted to high-speed casting scenarios. The layout of the four guide holes is designed to further increase the residence time of molten steel by increasing the height and bottom area of the hollow cavity, thereby enhancing the floating of inclusions. At the same time, by matching the area of the guide holes, the flow velocity at the top corner is suppressed to ensure the stability of the flow field and meet the quality requirements of the cast billet under high casting speed.
[0049] Comparative Example 1 This comparative example is based on Example 3, with the guide holes set on the side wall of the controller body 1. Two guide holes (tilt angle 20°) are evenly arranged on each side wall. The guide holes include two specifications, with the same area as in Example 3. The area of the upper outlet 4 is 0.0512m², the same as in Example 3.
[0050] Using the multi-channel turbulence controller body 1 provided in Example 3 and Comparative Example 1, according to Figure 3The tundish was fixedly installed at the bottom of the tundish, directly below the long nozzle, and used for continuous casting during ladle changes to verify the purification of molten steel and the formation of sand holes. The inner cavity height of the tundish used in the experiment was 1000 mm. The cross-sectional area of the long nozzle corresponding to Example 3 was 0.0064 m². The cross-sectional area of the long nozzle in Comparative Example 1 was the same as that in Example 3, except that all the guide holes were set on the sidewall (tilt angle 20°). The rest of the structure and parameters were completely the same as those in Example 3. The experimental steel was Q235B ordinary carbon steel, the continuous casting speed was 1.8 m / min, the molten steel level fluctuation range during ladle changes was ±150 mm, conventional carbonaceous protective slag was used in the tundish, the casting cycle was 8 hours, each experiment was repeated 3 times, and the average value was taken as the final result.
[0051] Detection indicators and methods: (1) Steel purification effect: The total oxygen content (T[O]) of the molten steel at the outlet of the tundish was detected by an oxygen-nitrogen analyzer, and the number of inclusions under the surface of the billet (size ≥5μm) was counted by a metallographic microscope. The inclusion flotation rate was calculated by (total oxygen content at the inlet - total oxygen content at the outlet) / total oxygen content at the inlet.
[0052] (2) Sand hole formation: Sand hole defects on the surface of the billet were detected by visual inspection and magnetic particle testing. The number of sand holes per meter of billet and the maximum size of the sand hole were counted. At the same time, the number of slag holes formed during the ladle change period and the disturbance of the slag-gold interface were recorded.
[0053] Using the multi-channel turbulence controllers provided in Example 3 and Comparative Example 1, the purification effect of the molten steel obtained in the experiment is shown in Table 1, and the comparison of the formation of sand holes is shown in Table 2.
[0054] Table 1: detection indicators Example 3 Comparative Example 1 Increase Total oxygen content T [O] at the tundish outlet 18ppm 27ppm 33.3% (decreased) Number of subcutaneous inclusions in the cast billet (number per mm²) 1.2 2.7 57.1% (decreased) Inclusion float rate 42.9% 25.0% 71.6% (increase) Temperature uniformity of molten steel during ladle change (°C) ±3℃ ±8℃ 62.5% (Improvement) Table 2: detection indicators Example 3 Comparative Example 1 Improvement range Number of pinholes per meter of cast billet (number per meter) 0.3 1.7 82.4% (decreased) Maximum trachoma size (mm) 0.8 2.5 68.0% (decreased) Number of slag holes formed during ladle change (times / furnace) 0 3 100% (Eliminated) Slag-Gold Interface Disturbance Level (Level 1-5, Level 5 is the most severe) Level 1 (Stable) Level 4 (Severe fluctuations) 75% (improvement) Compared to Comparative Example 1 (sidewall guiding flow hole structure), the multi-channel turbulence controller device of Embodiment 3 of the present invention exhibits excellent steel purification effect and sand hole suppression capability during continuous casting in the ladle change period: the total oxygen content of the steel is reduced by 33.3%, the inclusion flotation rate is increased by 71.6%, the number of subsurface inclusions in the billet is reduced by 57.1%, and the cleanliness of the steel is significantly improved; the number of sand holes per meter of billet is reduced by 82.4%, the maximum sand hole size is reduced by 68.0%, the formation of slag holes during the ladle change period is completely eliminated, and the stability of the slag-gold interface is greatly improved; it effectively solves the problems of uneven flow field, serious slag entrainment, and many sand hole defects of traditional sidewall guiding flow hole turbulence controllers, significantly improves the billet quality and the smoothness of continuous casting production, and fully meets the needs of high-end steel continuous casting production.
[0055] In summary, this invention achieves stable, uniform, and controllable regulation of the molten steel flow state through the synergistic design of multi-channel diversion, differentiated cross-sectional area matching, and energy dissipation from mutual interference among multiple streams. It effectively solves the problems of large flow velocity impact, uneven flow field distribution, easy slag-gold interface rupture, slag entrapment, and severe secondary oxidation that exist in traditional single-channel structures during ladle and flow switching. By decomposing the high-speed concentrated injection flow into multiple low-speed diversions, the impact kinetic energy of the molten steel on the slag layer at the bottom and top of the chamber is significantly reduced, avoiding phenomena such as slag layer tearing, slag hole formation, exposed molten steel, and secondary oxidation caused by excessive impact. By matching the cross-sectional area of the guide holes at different positions, the overall flow field distribution inside the controller is balanced, eliminating local eddies, dead zones, and sudden changes in flow velocity, thus improving the stability and uniformity of the molten steel flow. The multi-stream diversion creates a flow state of mutual interference and cancellation within the controller, further consuming the remaining kinetic energy of the molten steel, reducing the vertical upward flow intensity, stabilizing the slag-metal interface during ladle changes, reducing slag entrapment, secondary oxidation, inclusion accumulation, and nozzle blockage, significantly improving the cleanliness of the molten steel and the smoothness of continuous casting production, and providing a reliable guarantee for the production of high-quality billets.
[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. These modifications or substitutions, or combinations of technical features in the above embodiments that do not conflict with each other, can be made in accordance with the manner described in the embodiments. These modifications, substitutions or combinations do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A multi-channel turbulence controller device, characterized in that, It includes a controller body (1) and a hollow chamber (2) formed inside it; The controller body (1) is a cuboid or cylindrical structure, and its interior is a hollow cavity (2) of a cuboid or cylindrical shape; a square upper outlet (4) is provided at the geometric center of the upper surface of the controller body (1), and the upper outlet (4) is connected to the hollow cavity (2). The bottom area of the hollow inner cavity (2) is 38-45 times the cross-sectional area of the long nozzle; the internal height of the hollow inner cavity (2) is 1 / 5-3 / 5 of the height of the tundish inner cavity; the area of the upper outlet (4) is 7-9 times the cross-sectional area of the long nozzle. Around the upper outlet (4), with the upper outlet (4) as the center, there are vertical guide holes that penetrate the upper surface of the controller body (1) in a centrally symmetrical manner. The number of guide holes is 4-8. The guide holes include a first guide hole (31) and a second guide hole (32). The second guide hole (32) is located on the extension line of the diagonal of the upper outlet (4), and the first guide hole (31) is located on the extension line of the midline of any two opposite sides of the upper outlet (4).
2. The multi-channel turbulence controller device according to claim 1, characterized in that, The controller body (1) is a cuboid structure with square walls on its upper and lower surfaces and rectangular walls on all four sides. Its internal hollow cavity (2) is a cuboid cavity. The bottom area of the hollow inner cavity (2) is 42-45 times the cross-sectional area of the long nozzle; the internal height of the hollow inner cavity (2) is 1 / 5 of the height of the tundish inner cavity; the area of the upper outlet (4) is 8 times the cross-sectional area of the long nozzle.
3. The multi-channel turbulence controller device according to claim 2, characterized in that, The area of the first guide hole (31) is larger than that of the second guide hole (32); the area of the first guide hole (31) is 0.55-0.56 times the cross-sectional area of the long water inlet, and the area of the second guide hole (32) is 0.24-0.26 times the cross-sectional area of the long water inlet.
4. The multi-channel turbulence controller device according to claim 2, characterized in that, On the upper surface of the controller body (1), an edge (22) is formed between the upper outlet (4) and the outer edge of the controller body (1), and the guide hole is provided on the edge (22).
5. The multi-channel turbulence controller device according to claim 4, characterized in that, The sum of the areas of all the guide holes accounts for 5%-10% of the upper surface area of the controller body (1), and the cross-sectional area of the upper outlet (4) accounts for 7-16% of the upper surface area of the controller body (1).
6. The multi-channel turbulence controller device according to claim 2, characterized in that, The number of the guide holes is 8, including 4 first guide holes (31) and 4 second guide holes (32), wherein the second guide holes (32) are located at the four vertices of the upper surface of the square; the first guide holes (31) are located at the midpoint of the line connecting two adjacent second guide holes (32).
7. The multi-channel turbulence controller device according to claim 6, characterized in that, The distance from the second guide hole (32) to the edge of the upper surface of the controller body (1) is 0.1-0.12 of the side length of the upper surface; the distance from the first guide hole (31) to the edge of the upper surface of the controller body (1) is 0.08-0.1 of the side length of the upper surface.
8. The multi-channel turbulence controller device according to any one of claims 1-7, characterized in that, The upper surface of the controller body (1) is a detachable cover plate, on which the upper outlet (4) and the guide hole are provided, and the specifications and / or number of the upper outlet (4) and the guide hole provided on different cover plates are different.
9. A continuous casting tundish, characterized in that, The device includes a multi-channel turbulence controller as described in any one of claims 1-8, which is fixedly installed at the bottom of the intermediate tank, directly below the long nozzle.