A non-steady-state anti-rolling method for liquid surface of a sizing tundish

Abstract

The present application relates to steel metallurgy continuous casting technical field, specifically disclose a kind of sizing tundish liquid level non-steady-state anti-coiling slag method, suction nozzle is rotated to working position by standby position under the control of suction nozzle control mechanism, suction nozzle is lowered, until inserted below the molten steel of tundish;Molten steel mixed slag enters suction nozzle, under the wave layout of the inner surface of suction nozzle, slag inclusions are gathered in the recess of wave layout of suction nozzle under the condition of turbulent negative pressure, purified molten steel flows out from below invasive nozzle into crystallizer;After operation is completed, suction nozzle is lifted out of the molten steel of tundish, and rotated to standby position, manually clean the internal steel slag of suction nozzle using oxygen blowing tube;When it is necessary to carry out molten steel liquid level non-steady-state operation, repeat steps S1-S3;The present application is beneficial to the cleaning work of foreign matter in suction nozzle;Solve the molten steel quality problem caused by tundish liquid level non-steady-state condition.

Description

Technical Field

[0001] This invention relates to the field of continuous casting technology in iron and steel metallurgy, specifically to a method for preventing slag entrapment in an unsteady state of the liquid surface in a sizing tundish. Background Technology

[0002] The tundish is the core container connecting the ladle and the crystallizer in continuous casting, serving dual functions of buffering and diverting flow while also refining the metallurgical process. At a basic level, it stores molten steel to enable continuous casting across multiple furnaces and distributes it smoothly to each crystallizer via the bottom nozzle, while simultaneously reducing flow rate and pressure to protect the initial billet shell. At a metallurgical level, it removes inclusions and purifies the molten steel using methods such as baffles, argon blowing, and filtration; it precisely controls the casting temperature through heat preservation or heating; and it employs sealants and covering agents to prevent secondary oxidation of the molten steel.

[0003] Unsteady slag entrainment technology in continuous casting tundish is a key focus in the continuous casting process of iron and steel metallurgy, primarily addressing the slag entrainment problem caused by molten steel fluctuations and unsteady pouring. During ladle changes in continuous casting, as the molten steel level drops, the Coriolis effect creates converging vortices at the steel-slag interface. These vortices easily cause slag entrainment. When the molten steel height falls below the critical vortex height, the vortex can even entrain gas, leading to a large amount of slag entering the nozzle, which is highly detrimental to the production of clean steel. Furthermore, during tundish slag removal operations (i.e., when the tundish top slag thickness exceeds 50mm), the molten steel level rises, altering the tundish flow field. Slag adhering to the inner wall of the tundish re-enters the molten steel. These unstable factors greatly increase the likelihood of slag entrainment, posing a significant challenge to the stable control of molten steel quality.

[0004] Traditional anti-slag entrapment technology mainly utilizes mechanical anti-slag entrapment devices. These devices suppress vortex formation by incorporating various flow control structures. For example, a novel anti-slag entrapment seat brick for continuous casting tundishes (patent number: CN205096528U) features a frustum-shaped groove and a specific edge height. When the molten steel level in the tundish falls below the groove edge, the continuous casting crystallizer automatically cuts off the flow, effectively preventing the adverse effects of continuous pouring under vortex conditions on steel quality. This device employs a special design for the bottom seat brick of the tundish to interrupt flow and prevent slag entrapment. However, during normal production, to ensure continuous casting, the steel flow in the tundish cannot be interrupted. Therefore, this method is only suitable for preventing large amounts of slag during tundish shutdown and is ineffective against unsteady slag entrapment in the flow field during production. At that time, a slag suppression control device for tundishes, its preparation, and slag suppression control method were disclosed, patent number: CN114799140A. The anti-slag-entrapment stopper rod device, by setting an inhibition ring and an anti-rotation structure, can effectively prevent the inhibition ring from rotating, ensuring the effect of suppressing converging vortices. This technology solves the problem that the slag-blocking effect of continuous casting tundishes is poor, resulting in a large workload for handling casting residue, and the slag-blocking device is costly and difficult to maintain, making it difficult to widely adopt. Therefore, this device is mainly used to control and reduce casting residue in the tundish, and the main technical means is still to control the occurrence of vortices. It is difficult to achieve good results in addressing the slag entrapment caused by changes in the tundish flow field during normal casting. Furthermore, this patent applies to stopper rod tundishes and does not address the same problem in sizing tundishes. Therefore, there is an urgent need to develop a device and method for preventing slag entrapment in unsteady liquid surface conditions in sizing tundishes. Summary of the Invention

[0005] To address the problems existing in the prior art, the present invention aims to provide a method for preventing slag entrapment due to unsteady flow conditions in the tundish liquid surface during sizing. This method utilizes the flow of steel within the slag suction nozzle to adsorb passing slag and inclusions, thus solving the problem of unsteady slag entrapment caused by abrupt changes in the flow field due to a drop or rise in the tundish liquid surface. It is applicable to normal tundish ladle replacement processes, slag removal processes, and control of tundish casting residue. It plays a significant role in improving the continuous stability of molten steel quality and also significantly contributes to the homogenization of steel product performance.

[0006] The technical solution adopted by this invention to solve its technical problem is: a method for preventing slag entrapment during unsteady liquid surface conditions in sizing, comprising the following steps:

[0007] S1. Under the control of the slag suction nozzle control mechanism, the slag suction nozzle rotates from the standby position to the working position and descends until it is below the molten steel inserted into the tundish.

[0008] S2. The molten steel mixed with slag enters the slag suction nozzle. Under the wave pattern on the inner surface of the slag suction nozzle, the slag inclusions gather in the depression of the wave pattern of the slag suction nozzle under the turbulent negative pressure. The purified molten steel flows out from below the intrusion nozzle and enters the crystallizer.

[0009] S3. After the operation is completed, the molten steel in the tundish is lifted out of the slag suction nozzle and rotated to the standby position. The slag inside the slag suction nozzle is then cleaned manually using an oxygen blowing pipe.

[0010] S4. When it is necessary to perform unsteady operation of molten steel surface, repeat steps S1-S3.

[0011] Specifically, in step S1, the molten steel in the tundish is inserted as follows: the molten steel inlet of the slag suction nozzle is inserted 60-80mm below the molten steel surface, and the molten steel inlet at the upper part of the slag suction nozzle is inserted into the molten steel when the tundish liquid surface is greater than or equal to 800mm, and the molten steel inlet at the lower part of the slag suction nozzle is inserted into the molten steel when the liquid surface is less than 800mm.

[0012] Specifically, the slag suction nozzle is provided with molten steel inlets at both the upper and lower parts, and there are two symmetrical molten steel inlets. The upper molten steel inlet is 400-500mm away from the upper end of the slag suction nozzle, and the lower molten steel inlet is 300-400mm away from the lower end of the slag suction nozzle.

[0013] Specifically, the total length of the sludge suction port is 1.0~1.2m, and the inner diameter of the sludge suction port is 30~40mm.

[0014] Specifically, the wave pattern in step S2 is a corrugated protrusion on the inner wall of the slag suction port, the slag suction port is made of aluminum-carbon material, and a threaded sleeve is provided on the top of the slag suction port, the threaded sleeve being a graphite ring.

[0015] Specifically, the slag suction port control mechanism includes a base, a rotating disk, and a frame. A power box is installed on the base, and the rotating disk is controlled by two hydraulic cylinders inside the power box. The rotating disk is installed in the middle of the power box through a bearing seat. The frame is installed on the rotating disk, a driven wheel is installed on the upper part of the frame, and a drive wheel is installed at the bottom of the frame. The drive wheel is connected to a drive motor, which is installed on the frame. A lifting chain is installed between the drive wheel and the driven wheel, and the drive motor controls the rotation of the lifting chain.

[0016] Specifically, a connecting frame is installed on the lifting chain via a fixing clamp, a connecting block is installed on the connecting frame, the connecting block is a threaded rod, the threaded rod is threadedly connected to a threaded sleeve, and a slag suction port is installed on the connecting frame.

[0017] Specifically, in step S3, a circular hole is provided on the top cover of the intermediate tundish's immersion nozzle, allowing the slag suction nozzle to enter. The intermediate tundish has n flow rates, and n sets of anti-slag entrapment devices are correspondingly installed.

[0018] Specifically, the unsteady state of the molten steel level in step S4 includes ladle replacement and tundish slag removal.

[0019] The present invention has the following beneficial effects:

[0020] This invention presents a method for preventing slag entrapment in a tundish under unsteady conditions. It systematically considers slag entrapment caused by vortexing and turbulent flow in the tundish. During continuous casting, slag entrapment is an unavoidable problem due to complex factors such as metallurgical requirements, production continuity, and the inability of the ladle to open automatically. Therefore, how to clean and purify slag entrapment in molten steel is a key issue that metallurgists are focusing on. Another metallurgical phenomenon is that due to numerous inclusions or slag entrapment, a large amount of inclusions adhere to the tundish submersible nozzle, affecting the steel throughput and the casting speed of the continuous casting machine. Inspired by these metallurgical phenomena... Since the slag entrainment problem cannot be completely avoided, the same mechanism is used to purify the molten steel before it enters the crystallizer, thus allowing for early prediction and appropriate countermeasures. Secondly, to improve the adsorption effect of the nozzle on inclusions, slag entrainment, and other foreign matter, the inner wall of the nozzle adopts a wave-shaped inner surface design. The sudden change in the molten steel flow velocity enhances the turbulent negative pressure adsorption effect when the molten steel flows through, promoting the collision and aggregation of inclusions. In addition, the slag suction nozzle adopts a design with molten steel inlets at both the upper and lower ends, which facilitates multiple captures of the steel-slag mixture under high liquid level conditions, further increasing the purity of the molten steel, thereby achieving the purpose of multi-stage purification of molten steel.

[0021] This invention presents a method for preventing slag entrapment in a non-steady-state tundish liquid level. The lifting and rotating mechanism of the slag suction nozzle facilitates the cleaning of inclusions and other foreign matter adsorbed on the inner surface of the nozzle, providing technical support for the repeated use of the nozzle. Furthermore, this invention is not only applicable to handling turbulent slag entrapment caused by sudden changes in the flow field during normal production, but also addresses the technical requirement of reducing casting allowance. By utilizing the molten steel inlet at the lower end of the slag suction nozzle, the vortex velocity at low liquid levels is reduced, suppressing vortex slag entrapment while simultaneously adsorbing a large amount of vortex slag. This achieves stable control of vortex slag entrapment under high-low liquid level conditions in the tundish. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the layout structure of the anti-slag entrapment device for unsteady liquid surface in the sizing tundish.

[0023] In the diagram: 1-Tundish; 2-Slag suction nozzle; 2.1-Molten steel inlet; 2.2-Corrugated protrusion; 3-Slag suction nozzle control mechanism; 3.1-Rotating disc; 3.2-Power box; 3.3-Lifting chain; 3.4-Frame; 3.5-Drive wheel; 3.6-Driven wheel; 3.7-Connecting frame; 3.8-Connecting head; 4-Intrusion nozzle; 5-Crystallizer; 6-Sector section. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0025] like Figure 1 As shown, a device for preventing slag entrapment in a sizing tundish with an unsteady liquid surface and its usage method are disclosed. The device includes a slag suction port 2 and a slag suction port control mechanism 3, which are connected by a threaded structure. The slag suction port 2 is similar to an immersion port 4, but with a sealed top. The slag suction port 2 has two sets of molten steel inlets 2.1, and the interior of the slag suction port 2 features a wave-like internal surface design. The wave pattern consists of corrugated protrusions 2.2 on the inner wall of the slag suction port 2. The slag suction port 2 is made of aluminum-carbon alloy. A threaded sleeve is installed at the top of the slag suction nozzle 2, and the threaded sleeve is made of graphite ring. Before the steel liquid surface becomes unsteady, such as during ladle replacement or slag discharge from the tundish, the slag suction nozzle 2 utilizes its internal wave-like layout structure to create a large turbulent negative pressure on the inner surface when the steel-slag mixture passes through, thereby adsorbing foreign objects such as slag entrapment and inclusions, and purifying the steel. The device also includes a slag suction nozzle control mechanism 3 for the slag suction nozzle 2, which facilitates the cleaning of foreign objects inside the slag suction nozzle 2. This method solves the steel quality problem caused by the unsteady liquid surface of the tundish 1.

[0026] The slag suction inlet control mechanism 3 includes a base, a rotating disk 3.1, a power box 3.2, a lifting chain 3.3, a frame 3.4, a connecting frame 3.7, and a connector 3.8. The power box 3.2 is mounted on the base. The power box 3.2 uses dual hydraulic cylinders to control the rotation of the rotating disk 3.1. The rotating disk 3.1 is mounted in the middle of the power box 3.2 via a bearing seat. The power box 3.2 uses existing hydraulic cylinders to control the rotation of the rotating disk 3.1 via a worm gear. A gear ring is set on the outside of the rotating disk 3.1. An angle encoder is set on the rotating part of the rotating disk 3.1 to identify and control the rotation angle.

[0027] A frame 3.4 is mounted on a rotating disk 3.1. A driven wheel 3.6 is mounted on the upper part of the frame 3.4, and a drive wheel 3.5 is mounted on the bottom of the frame 3.4. The drive wheel 3.5 is connected to a drive motor, which is mounted on the frame 3.4. A lifting chain 3.3 is installed between the drive wheel 3.5 and the driven wheel 3.6. The drive motor controls the rotation of the lifting chain 3.3. An angle encoder is installed on the output shaft of the drive motor to identify and control the lifting height of the lifting chain 3.3.

[0028] A connecting frame 3.7 is installed on the lifting chain 3.3 via a fixing clamp. A connecting block 3.8 is installed on the connecting frame 3.7. The connecting block 3.8 is made of a threaded rod, and the threaded rod is connected to a threaded sleeve. A slag suction port 2 is installed on the connecting frame 3.7.

[0029] A method of using the above-mentioned anti-slag entrapment device for unsteady liquid surface in a sizing tundish includes the following steps:

[0030] 1) Before non-steady-state operations such as slag discharge from tundish 1 or ladle replacement, the slag suction nozzle 2 is rotated from the standby position to the working position under the control of the slag suction nozzle control mechanism 3. The slag suction nozzle 2 is lowered until it is inserted below the molten steel. The molten steel inlet of the slag suction nozzle is inserted 60-80mm below the molten steel surface. The molten steel inlet of the upper part of the slag suction nozzle is inserted into the molten steel when the tundish liquid surface is greater than or equal to 800mm. The molten steel inlet of the lower part of the slag suction nozzle is inserted into the molten steel when the liquid surface is less than 800mm.

[0031] 2) When slag discharge from tundish 2 or ladle replacement is started, non-steady-state operations are performed. Molten steel mixed with slag enters slag suction nozzle 2. Under the wave-like layout of the inner surface of the slag suction nozzle, slag and other inclusions accumulate in the depression of the slag suction nozzle under turbulent negative pressure. The purified molten steel flows out from below the intrusion nozzle 4 and enters the crystallizer 5. The molten steel in the crystallizer 5 flows into the fan-shaped section 6 of the continuous casting machine.

[0032] 3) After the operation is completed, the slag suction nozzle 2 lifts out the molten steel from the tundish 1 and rotates to the standby position. The slag adhering inside the slag suction nozzle 2 is then cleaned manually using the oxygen blowing pipe.

[0033] 4) When it is necessary to perform another inspection or other operations that are not in a steady state of the molten steel level, repeat steps 1), 2), and 3) above.

[0034] Example 1

[0035] The sizing tundish 1 produces Q355B steel. Each set of slag suction nozzles 2 has two symmetrical molten steel inlets 2.1. The upper set of molten steel inlets 2.1 is 500mm from the top, and the lower set is 400mm from the bottom. The total length of slag suction nozzles 2 is 1.2m, and the inner diameter is 35mm. The top slag thickness of tundish 1 is 60mm (required to be less than 50mm), and inspection is required. During inspection, the liquid level in tundish 1 should be 900mm. The continuous casting machine speed is 0.95m / min.

[0036] S1: Under the control of the slag suction port control mechanism 3, the slag suction port 2 rotates from the standby position to the working position and descends until it is inserted below the molten steel. The angle encoder of the lifting chain 3.3 controls the upper molten steel inlet 2.1 to be inserted 80mm below the molten steel surface.

[0037] S2: Start the tundish slag removal operation. Most of the molten steel mixed with slag enters the upper molten steel inlet 2.1 of the slag suction nozzle 2, and a small part enters the lower molten steel inlet 2. Under the wave-like layout of the inner surface of the slag suction nozzle 2, slag and other inclusions accumulate in the depression of the slag suction nozzle 2 under turbulent negative pressure. The purified molten steel flows out from below the intrusion nozzle 4 and enters the crystallizer 5.

[0038] S2: After the operation is completed, the slag suction nozzle 2 lifts out the molten steel from the tundish 1 and rotates to the standby position. The corrugated protrusions 2.2 on the upper and lower parts of the slag suction nozzle 2 adsorb some of the impurities. The steel slag adhering inside the slag suction nozzle 2 is cleaned manually using an oxygen blowing pipe.

[0039] During the slag removal process of tundish 1, the submerged entry nozzle 4 was clean, the continuous casting machine speed was normal (0.95m / min), and the billet landing inspection was normal, with no surface or internal quality problems found.

[0040] Example 2

[0041] Tundish 1, used for sizing, produces Q235B steel. The continuous casting machine has a casting speed of 0.98 m / min. Each set of slag suction nozzles has two symmetrical molten steel inlets 2.1. The upper set of molten steel inlets 2.1 is 400 mm from the top, and the lower set is 300 mm from the bottom. Slag suction nozzle 2 has a total length of 1.0 m and an inner diameter of 35 mm. When the ladle needs to be replaced, a ladle replacement operation is required. At this time, the liquid level in tundish 1 is 600 mm.

[0042] S1: Under the control of the slag suction port control mechanism 3, the slag suction port 2 rotates from the standby position to the working position and descends until it is inserted below the molten steel. The angle encoder of the lifting chain 3.3 controls the upper molten steel inlet 2.1 to be inserted 80mm below the molten steel surface.

[0043] S2: Start the tundish 1 change and pouring operation. The molten steel mixed with slag enters the slag suction nozzle 2. Under the wave layout of the inner surface of the slag suction nozzle 2, the slag and other inclusions gather in the depression of the slag suction nozzle 2 under the turbulent negative pressure. The purified molten steel flows out from below the submerged entry nozzle 4 and enters the crystallizer 5.

[0044] S2: After the operation is completed, the slag suction nozzle 2 lifts out the molten steel from the tundish 1 and rotates to the standby position. The lower part of the slag suction nozzle 2 adsorbs some of the impurities. The steel slag adhering inside the slag suction nozzle 2 is cleaned manually using an oxygen blowing pipe.

[0045] During the tundish 1 changeover process, the immersion nozzle 4 was clean, the continuous casting machine speed was normal (0.97 m / min), and the billet landing inspection was normal, with no surface or internal quality problems found.

[0046] Example 3

[0047] The sizing tundish 1 produces steel grade S355NL, with a continuous casting machine speed of 0.92 m / min. Each set of slag suction nozzles 2 has two symmetrical molten steel inlets 2.1. The upper set of molten steel inlets 2.1 is 400 mm from the top, and the lower set is 300 mm from the bottom. The total length of slag suction nozzles 2 is 1.0 m, and the inner diameter of slag suction nozzles 2 is 30 mm. During the casting process of the ladle, the ladle nozzle suddenly breaks, and the ladle is left open for casting. A new ladle nozzle needs to be replaced. The liquid level in tundish 1 is 700 mm.

[0048] S1: Under the control of the slag suction nozzle control mechanism 3, the slag suction nozzle 2 rotates from the standby position to the working position and descends until it is inserted below the molten steel. The angle encoder of the lifting chain 3.3 controls the position of the upper molten steel inlet 2.1 at 70mm from the molten steel surface.

[0049] S2: Molten steel mixed with slag enters the slag suction nozzle 2. Under the wave-like layout of the inner surface of the slag suction nozzle 2, slag and other inclusions accumulate in the depression of the slag suction nozzle 2 under turbulent negative pressure. The purified molten steel flows out from below the submerged entry nozzle 4 and enters the crystallizer 5.

[0050] S2: After the operation is completed, the slag suction nozzle 2 lifts out the molten steel from the tundish 1 and rotates to the standby position. The lower part of the slag suction nozzle 2 adsorbs some of the impurities. The steel slag adhering inside the slag suction nozzle 2 is cleaned manually using an oxygen blowing pipe.

[0051] During the process of changing the tundish nozzle from tundish 1 to the main tundish nozzle, the submerged nozzle 4 was clean, the continuous casting machine speed was normal (0.92m / min), and the billet landing inspection was normal, with no surface or internal quality problems found.

[0052] In summary, the present invention has achieved significant metallurgical results in addressing the problem of unsteady slag entrapment on the tundish steel surface, effectively ensuring the uniformity of molten steel quality. This invention employs reverse thinking to find a breakthrough, addressing the challenge of controlling turbulent flow and vortices in the tundish 1 flow field. It utilizes an inclusion collection device to overcome previously difficult problems. The collection device and its usage method combine the technical features of inclusion adsorption, the timing of turbulent slag entrapment in the tundish 1, and a multi-stage collection method, successfully overcoming the major challenge of casting quality fluctuations in the continuous casting machine's tundish 1. This provides a practical technical method for stable production and quality control in continuous casting machines. Furthermore, the device has a periodic cleaning function, enabling the repeated and low-cost reuse of the inclusion collection device.

[0053] The upper and lower limits of the process parameters (such as temperature, time, etc.) and the range values ​​of the present invention can all achieve this method, and examples are not listed here.

[0054] This invention is not limited to the above-described embodiments. Anyone should know that any structural changes made under the guidance of this invention, and any technical solutions that are the same as or similar to this invention, fall within the protection scope of this invention.

[0055] The technologies, shapes, and structures not described in detail in this invention are all known technologies.

Claims

1. A method for preventing slag entrapment during unsteady liquid surface conditions in sizing processes, characterized in that, Includes the following steps: S1. Under the control of the slag suction nozzle control mechanism, the slag suction nozzle rotates from the standby position to the working position and descends until it is below the molten steel inserted into the tundish. S2. The molten steel mixed with slag enters the slag suction nozzle. Under the wave pattern on the inner surface of the slag suction nozzle, the slag inclusions gather in the depression of the wave pattern of the slag suction nozzle under the turbulent negative pressure. The purified molten steel flows out from below the intrusion nozzle and enters the crystallizer. S3. After the operation is completed, the molten steel in the tundish is lifted out of the slag suction nozzle and rotated to the standby position. The slag inside the slag suction nozzle is then cleaned manually using an oxygen blowing pipe. S4. When it is necessary to perform unsteady operation of molten steel surface, repeat steps S1-S3.

2. The method for preventing slag entrapment in a non-steady-state liquid surface of a tundish according to claim 1, characterized in that, In step S1, the molten steel in the tundish is as follows: the molten steel inlet of the slag suction nozzle is inserted 60-80mm below the molten steel surface, and the molten steel inlet at the upper part of the slag suction nozzle is inserted into the molten steel when the tundish liquid surface is greater than or equal to 800mm, and the molten steel inlet at the lower part of the slag suction nozzle is inserted into the molten steel when the liquid surface is less than 800mm.

3. The method for preventing slag entrapment in a non-steady-state liquid surface of a sizing tundish according to claim 2, characterized in that, The slag suction nozzle is provided with molten steel inlets at both the upper and lower parts. There are two molten steel inlets symmetrically arranged. The upper molten steel inlet is 400~500mm away from the upper end of the slag suction nozzle, and the lower molten steel inlet is 300~400mm away from the lower end of the slag suction nozzle.

4. The method for preventing slag entrapment in a non-steady-state liquid surface of a tundish according to claim 2, characterized in that, The total length of the sludge suction port is 1.0~1.2m, and the inner diameter of the sludge suction port is 30~40mm.

5. The method for preventing slag entrapment in a non-steady-state liquid surface of a sizing tundish according to claim 1, characterized in that, The wave pattern in step S2 is a corrugated protrusion on the inner wall of the slag suction nozzle. The slag suction nozzle is made of aluminum-carbon material, and a threaded sleeve is provided on the top of the slag suction nozzle. The threaded sleeve is made of graphite ring.

6. The method for preventing slag entrapment in a non-steady-state liquid surface of a sizing tundish according to claim 5, characterized in that, The slag suction port control mechanism is equipped with a base, a rotating disk, and a frame. A power box is installed on the base, and the rotating disk is controlled by two hydraulic cylinders inside the power box. The rotating disk is installed in the middle of the power box through a bearing seat. The frame is installed on the rotating disk, a driven wheel is installed on the upper part of the frame, and a drive wheel is installed at the bottom of the frame. The drive wheel is connected to a drive motor, which is installed on the frame. A lifting chain is installed between the drive wheel and the driven wheel, and the drive motor controls the rotation of the lifting chain.

7. The method for preventing slag entrapment in a non-steady-state liquid surface of a tundish according to claim 6, characterized in that, The lifting chain is mounted on a connecting frame via a fixed clamp. A connecting block is mounted on the connecting frame. The connecting block is made of a threaded rod, which is threadedly connected to a threaded sleeve. A slag suction port is mounted on the connecting frame.

8. The method for preventing slag entrapment in a non-steady-state liquid surface of a sizing tundish according to claim 1, characterized in that, In step S3, the tundish has a circular hole on the top of the intrusion nozzle, which allows the slag suction nozzle to enter. The tundish has n flow rates, and n sets of anti-slag entrapment devices are installed accordingly.

9. The method for preventing slag entrapment in a non-steady-state liquid surface of a sizing tundish according to claim 1, characterized in that, The unsteady state of the molten steel level in step S4 includes ladle replacement and tundish slag removal.

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