Device for reducing steel ladle roughing slag in heavy rail steel continuous casting process and control method

Abstract

The invention discloses a device for reducing steel ladle roughing slag in the heavy rail steel continuous casting process and a control method, and relates to the technical field of steel smelting, the device comprises a steel ladle shell and is provided with a heat preservation ladle cover, and the bottom of the steel ladle shell is provided with a top layer, a middle layer and a bottom layer and is of a step-shaped structure; a groove is formed in the middle layer and provided with a sewer pipe, an upper end opening of the sewer pipe is communicated with the groove, and the lower end of the sewer pipe extends to the outer side of the steel ladle shell; the weighing assembly is used for monitoring the total weight M of residual molten steel and slag in the steel ladle shell in real time; when the total weight M is reduced to a first preset threshold value, a slag discharging detection assembly is started; when the total weight M is further reduced to a second preset threshold value, the heat preservation ladle cover is removed; and when the slag tapping detection assembly detects that the proportion of the slag in the molten steel reaches a preset slag threshold value, the control unit starts the plate closing assembly to close the liquid outlet of the sewer pipe. According to the device for reducing the steel ladle roughing slag in the heavy rail steel continuous casting process, the technical problems that the metal yield is reduced and resources are wasted are solved.

Description

Technical Field

[0001] This invention relates to the field of iron and steel smelting technology, and in particular to a device and control method for reducing slag runoff from the ladle during the continuous casting process of heavy rail steel. Background Technology

[0002] In the continuous casting production of heavy rail steel, slag addition at the end of the casting process is a key factor leading to a decrease in the cleanliness of the molten steel and an increase in non-metallic inclusions. Traditional flat-bottomed ladles easily form strong eddies during the evacuation phase. When the liquid level drops to a critical depth, the covering slag is drawn into the drain nozzle, introducing large amounts of calcium fluoride and barium oxide, which not only contaminate the molten steel and exacerbate refractory corrosion but may also trigger secondary oxidation, significantly deteriorating the internal quality of the cast billet. Although existing technologies avoid slag addition by increasing the residual steel content (usually 800-1500 kg / heat), this results in reduced metal yield and resource waste, making it difficult to meet the requirements of green and low-carbon production.

[0003] Therefore, how to provide a device to reduce slag discharge from the ladle during the continuous casting process of heavy rail steel, improve the cleanliness of heavy rail steel, reduce steel consumption, and support high-quality green continuous casting are technical problems that need to be solved by those skilled in the art. Summary of the Invention

[0004] The purpose of this invention is to provide a device and control method for reducing slag runoff from the ladle during the continuous casting process of heavy rail steel, thereby solving the technical problems of reduced metal yield and resource waste.

[0005] To achieve the above objectives, the present invention provides a device for reducing slag runoff from the ladle during the continuous casting process of heavy rail steel, comprising:

[0006] A steel ladle shell is connected to an insulation cover. The bottom of the steel ladle shell is configured as a top layer, a middle layer and a bottom layer from top to bottom in a stepped structure. The middle layer has a groove with a depth equal to the thickness of the middle layer. A drain pipe is provided at the center of the groove. The upper opening of the drain pipe communicates with the groove, and the lower opening penetrates the bottom layer and extends to the outside of the steel ladle shell.

[0007] The weighing component and control unit are used to monitor the total weight M of the remaining molten steel and slag in the ladle shell in real time; when the total weight M drops to a first preset threshold, the control unit activates the slag detection component; when the total weight M further drops to a second preset threshold, the insulation ladle cover is removed.

[0008] The shut-off assembly is installed inside the drain pipe. When the slag detection assembly detects that the proportion of molten slag in the molten steel reaches a preset threshold, the control unit activates the shut-off assembly to close the outlet of the drain pipe.

[0009] Preferably, the thickness of the top layer is 100-105mm, and its horizontal cross-section is elliptical. The minor axis of the ellipse is 4 / 3 times the radius of the bottom of the steel cladding shell, and the major axis is 1.18 times the length of the minor axis.

[0010] Preferably, the thickness of the intermediate layer is 200-210mm, the groove is circular, and the diameter of the groove is 2 / 3 of the bottom radius of the steel ladle shell.

[0011] Preferably, the upper end face of the drain pipe is flush with the upper surface of the bottom layer, and the top layer, the middle layer and the bottom layer together form a stepped difference with a depth of 300-310mm.

[0012] Preferably, the heat-insulating cover adopts a double-layer high-temperature resistant structure, with an inner layer of ceramic fiber and an outer layer of heat-resistant steel plate.

[0013] Preferably, the system further includes a temperature acquisition module, which includes multiple thermocouple sensors. The thermocouple sensors are embedded in the slag layer region of the inner wall of the ladle shell and are spaced apart along the height direction of the ladle shell. The thermocouple sensors are electrically connected to the control unit.

[0014] Preferably, the first preset threshold is 20-22 tons, and the second preset threshold is 10-11 tons.

[0015] Preferably, the slag detection component is an electromagnetic detection system, and the preset threshold for molten slag is 20% of the molten slag volume.

[0016] A method for controlling slag runoff in the ladle during the continuous casting process of heavy rail steel is applied to the aforementioned device for reducing slag runoff in the ladle during the continuous casting process of heavy rail steel. The control method includes the following steps:

[0017] S1. During the casting process, the total weight M of the remaining molten steel and slag in the ladle shell is monitored in real time by the weighing component.

[0018] S2: When the total weight M drops to the first preset threshold, the control unit activates the slag detection component to detect the slag ratio of the molten steel flowing out of the drain pipe in real time.

[0019] S3: When the total weight M further decreases to the second preset threshold, the control unit issues a command to remove the heat insulation cover on the top of the ladle shell to increase the temperature gradient of the slag layer and increase the viscosity of the liquid slag at the steel-slag interface.

[0020] S4: When the slag detection component detects that the proportion of molten slag in the molten steel reaches the preset threshold, the control unit drives the shut-off plate component to close the outlet of the water pipe and terminate the casting.

[0021] Preferably, in step S4, the control unit triggers the shut-off component only when the slag detection component detects that the proportion of molten slag reaches or exceeds the preset threshold for molten slag in three consecutive samples.

[0022] Compared with the above-mentioned background technology, the device for reducing slag runoff from the ladle during the continuous casting process of heavy rail steel provided by the present invention has the following beneficial effects:

[0023] By setting a stepped structure consisting of a top layer, a middle layer, and a bottom layer at the bottom of the ladle, and configuring a groove and a drain pipe in the center of the middle layer, the flow field morphology of the molten pool at the end of casting is changed, the edge eddy intensity is weakened, and slag layer entrainment is suppressed, thereby reducing slag discharge behavior from the source.

[0024] Reducing metal loss, minimizing refractory corrosion and energy waste aligns with the steel industry's "dual carbon" goals, providing a reliable technical foundation for low-consumption, high-efficiency, and stable continuous casting of high-quality heavy rail steel. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0026] Figure 1 An isometric view of a device for reducing slag runoff from the ladle during the continuous casting process of heavy rail steel, provided in an embodiment of the present invention.

[0027] Figure 2 This is a partial front view of a device for reducing slag runoff from the ladle during the continuous casting process of heavy rail steel, provided in an embodiment of the present invention.

[0028] Figure 3 This is a top view of a device for reducing slag runoff from the ladle during the continuous casting process of heavy rail steel, provided in an embodiment of the present invention.

[0029] in:

[0030] 1-Steel cladding shell, 2-Top layer, 3-Middle layer, 4-Bottom layer, 5-Groove, 6-Drain pipe. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] Example 1:

[0034] See Figures 1-3 This invention provides a device for reducing slag discharge from the ladle during the continuous casting process of heavy rail steel. The device includes a ladle shell 1 connected to an insulated cover. The bottom of the ladle shell 1 is arranged in a stepped structure, consisting of a top layer 2, a middle layer 3, and a bottom layer 4 from top to bottom. The middle layer 3 has a groove 5, the depth of which is equal to the thickness of the middle layer 3. A drain pipe 6 is located at the center of the groove 5, with its upper opening communicating with the groove 5 and its lower opening penetrating the bottom layer 4 and extending to the outside of the ladle shell 1. A weighing component and a control unit are also included. The weighing component monitors the total weight M of the remaining molten steel and slag in the ladle shell 1 in real time. When the total weight M drops to a first preset threshold, the control unit activates the slag detection component. When the total weight M further drops to a second preset threshold, the insulated cover is removed. A shut-off component is located inside the drain pipe 6. When the slag detection component detects that the proportion of molten slag in the molten steel reaches the preset slag threshold, the control unit activates the shut-off component to close the outlet of the drain pipe 6.

[0035] Specifically, the ladle shell 1 is used to hold high-temperature molten steel and cover slag for the production of heavy rail steel. Its smelting chemical composition (mass percentage) consists of the following elements: C 0.75%~0.82%, Si 0.10%~0.40%, Mn 0.90%~1.20%, P≤0.025%, S≤0.025%, Cr0.40~0.50%, V0.04%~0.06%, with the remainder being Fe and other unavoidable impurities. A heat-insulating cover is detachably installed at the top opening to reduce heat loss and maintain a stable molten steel temperature. The bottom of the ladle shell 1 is constructed from top to bottom as a top layer 2, a middle layer 3, and a bottom layer 4, forming a stepped structure. This effectively changes the flow pattern of the molten steel pool at the end of casting, suppresses eddy formation, and reduces the risk of slag entrapment.

[0036] The central area of ​​the intermediate layer 3 is provided with a groove 5, the depth of which is equal to the thickness of the intermediate layer 3; a drain pipe 6 is provided in the center of the groove 5, the upper end of which is connected to the bottom of the groove 5, and the lower end of which penetrates the bottom layer 4 and extends to the outside of the steel ladle shell 1, serving as a channel for the outflow of molten steel.

[0037] The weighing component is used to monitor the total weight M of the remaining molten steel and slag inside the ladle shell 1 in real time. It includes multiple weighing sensors installed below the ladle support base (such as at the fulcrum of the turntable or ladle car) and directly bears the ladle load. The above-mentioned weighing component is a direct use of the prior art, and the structure of the component will not be described in detail here. The control unit is connected to the weighing component and the slag detection component.

[0038] The slag detection component is installed near the outlet of the drain pipe 6 or on the steel flow path. It detects the changes in the conductivity / magnetic permeability of the molten steel flow stream and analyzes the volume ratio of molten slag in real time. The gate component is integrated inside the drain pipe 6 or at the outlet. The gate is driven by a drive mechanism (such as a hydraulic cylinder, electric push rod or pneumatic actuator). It can quickly close the outlet of the drain pipe 6 after receiving a control signal to achieve emergency interception.

[0039] When the total weight M drops to the first preset threshold, the control unit automatically activates the slag detection component to perform real-time online detection of the slag ratio in the molten steel stream flowing from the drain pipe 6. When the total weight M further drops to the second preset threshold, the control unit issues a command to remove the insulation ladle cover to increase the temperature gradient between the slag layer surface inside the ladle and the environment, thereby increasing the viscosity of the liquid slag at the steel-slag interface and inhibiting its fluidity. When the slag detection component detects that the volume ratio of molten slag in the molten steel reaches the preset threshold, the control unit immediately drives the shut-off component to close the outlet of the drain pipe 6, terminating the casting process and preventing a high proportion of slag-containing molten steel from entering the tundish.

[0040] The workflow is as follows:

[0041] The ladle shell 1 contains the refined clean molten steel, and the top is covered with an insulated ladle cover to reduce heat loss. The molten steel flows steadily into the intermediate ladle through the bottom drain pipe 6. At this time, the total weight M in the ladle is high, and no control action is triggered.

[0042] As the casting process nears its end, the weighing assembly continuously monitors the total weight of the ladle. When M drops to 20 tons (the first preset threshold), the control unit determines that the casting process has entered its final stage and activates the slag detection assembly to begin real-time monitoring of the slag content in the flowing molten steel.

[0043] As casting continues, M is further reduced to 10 tons (the second preset threshold). The control unit issues a command to remove the insulation cover, which exposes the slag layer to the air. The surface temperature rises, causing the viscosity of the liquid slag at the steel-slag interface to increase significantly, thereby inhibiting the molten slag from being drawn into the drain pipe by the molten steel vortex.

[0044] The slag detection component continuously analyzes the proportion of molten slag in the molten steel stream. Once the molten slag volume ratio is detected to be ≥20% (molten slag preset threshold), the control unit immediately drives the shut-off component (such as a hydraulic or electric gate valve) to completely close the outlet of the downpipe 6 within 0.5–2 seconds, terminating casting and preventing high slag volume molten steel from contaminating the subsequent continuous casting system.

[0045] By setting a stepped structure consisting of a top layer, an intermediate layer, and a bottom layer at the bottom of the ladle, and configuring a groove and a drain pipe in the center of the intermediate layer, the flow field morphology of the molten pool at the end of casting is changed, the edge eddy intensity is weakened, and slag layer entrainment is suppressed. This reduces slag discharge from the source, reduces metal loss, refractory erosion, and energy waste, which aligns with the steel industry's "dual carbon" goal. It provides a reliable technical foundation for low-consumption, high-efficiency, and stable continuous casting of high-quality heavy rail steel, reduces the risk of slag discharge from the ladle, and improves the cleanliness and yield of heavy rail steel.

[0046] Based on the above embodiments, see Figure 3 The thickness of the top layer 2 is 100-105mm, preferably 100mm in this embodiment. Its horizontal cross-section is elliptical, and the length L1 of the minor axis of the ellipse is 4 / 3 times the radius R of the bottom of the steel cladding shell 1, that is... The length of the major axis L2 is 1.18 times the length of the minor axis, i.e., L2 = 1.18L1; the thickness of the intermediate layer 3 is 200-210mm, selected as 210mm; the groove 5 is circular, and the diameter d of the groove 5 is 2 / 3 of the bottom radius R of the steel ladle shell 1, i.e. The upper surface of the drain pipe 6 is flush with the upper surface of the bottom layer 4. The top layer 2, the middle layer 3 and the bottom layer 4 together form a stepped difference with a depth of 310mm. In the above formula, R is the bottom radius of the steel shell 1, L1 is the short axis length of the top layer, L2 is the long axis length of the top layer and d is the diameter of the groove 5.

[0047] Based on the above embodiments, the first preset threshold (i.e. the weight threshold for activating the slag detection component) is set to 20-22 tons, and preferably 22 tons in this embodiment. When the weighing component detects that the total weight M of the remaining molten steel and slag in the ladle shell 1 has dropped to this value, the casting has entered the final stage, and the slag detection component is activated to start real-time online monitoring of the slag content in the flowing molten steel.

[0048] The second preset threshold (i.e., the weight threshold for performing the insulation cover removal operation) is set to 10-11 tons, preferably 10 tons in this embodiment. When the total weight M further decreases to this value, the control unit issues a command to drive the actuator (such as a pneumatic device) to remove the insulation cover on the top of the ladle, thereby increasing the temperature gradient between the slag surface and the environment, increasing the viscosity of the liquid slag at the steel-slag interface, and thus inhibiting the molten slag from being drawn into the steel flow. The actuator in this application is a direct use of the prior art, and will not be described in detail here.

[0049] The slag detection component adopts an electromagnetic detection system, which is based on the significant difference between molten steel and slag in electromagnetic properties (such as conductivity and permeability). It uses an induction coil to perform non-contact detection on the molten steel stream flowing near the outlet of the drain pipe 6 and analyzes the volume ratio of slag in real time.

[0050] The slag preset threshold is set to 20%. That is, when the slag detection component detects that the volume ratio of slag in the molten steel stream reaches or exceeds 20% for several consecutive times, the control unit determines that significant slag discharge has occurred, immediately triggers the shut-off component to close the outlet of the water pipe 6, terminates the casting process, and prevents high slag molten steel from entering the tundish.

[0051] Based on the above embodiments, the heat insulation cover adopts a double-layer high-temperature resistant composite structure, including an inner layer and an outer layer. The inner layer is a ceramic fiber heat insulation layer (such as alumina fiber or mullite fiber).

[0052] The outer layer is a heat-resistant steel plate (such as alloy steel) to provide mechanical strength and resist high-temperature oxidation.

[0053] In addition, a temperature acquisition module is included to monitor the temperature distribution in the slag layer area inside the ladle in real time. The temperature acquisition module includes two or more thermocouple sensors, preferably K-type or S-type high-temperature thermocouples, with a temperature measurement range covering 800-1600℃. Each thermocouple sensor is embedded in the refractory material layer of the inner wall of the ladle shell 1, specifically arranged within the height range of the expected slag layer coverage area, and distributed at intervals along the height direction of the ladle shell 1 to obtain temperature gradient information of the upper, middle and lower parts of the slag layer.

[0054] A control method for reducing slag runoff in the ladle during the continuous casting process of heavy rail steel, applied to the device for reducing slag runoff in the ladle during the continuous casting process of heavy rail steel as described above, the control method includes the following steps:

[0055] S1. During the continuous casting process, the total weight M of the remaining molten steel and the covering slag in the ladle shell 1 is continuously monitored by a weighing component installed below the ladle support structure at a sampling frequency of not less than 1 Hz, and the real-time weight data is transmitted to the control unit.

[0056] S2. When the total weight M drops to the first preset threshold (preferably 20-22 tons, 22 tons in this embodiment), the control unit determines that the casting has entered the final stage and starts the slag detection component; the slag detection component performs non-contact online detection on the steel flow stream from the drain pipe and analyzes the volume ratio of molten slag in real time.

[0057] S3. When the total weight M further decreases to the second preset threshold (preferably 10-11 tons, 10 tons in this embodiment), the control unit issues a control command to drive the actuator to remove the insulation cover on the top of the ladle shell 1. After the insulation cover is removed, the slag layer surface is exposed to the air, which increases the viscosity of the liquid slag at the steel-slag interface, inhibits the fluidity of the molten slag, and reduces the risk of it being swept into the drain pipe by the swirling steel.

[0058] S4. When the slag detection component detects that the volume ratio of molten slag in the molten steel reaches or exceeds the preset threshold (preferably 20%) for multiple consecutive times (e.g., 3 consecutive times), the control unit immediately outputs a shutdown signal to drive the shut-off plate component to completely close the outlet of the water pipe 6, terminate the molten steel casting, prevent high slag molten steel from flowing into the tundish, and ensure the cleanliness of the subsequent continuous casting billet.

[0059] For the heats cast using the apparatus and control method of this invention, chemical composition analysis was performed on slag samples from the ladle impact zone covering agent. The results showed that the mass percentages of the characteristic components calcium fluoride and barium oxide originating from the ladle covering slag in the slag were significantly reduced, with an average calcium fluoride content of 1.1% and an average barium oxide content of 0.31%. Furthermore, weighing analysis of the casting residue after casting revealed that the residual steel weight per heat was reduced to 610 kg / heat, thus not only improving steel yield but also reducing metal loss.

[0060] Example 2:

[0061] The difference between this embodiment and Embodiment 1 is that the production of eutectoid rail steel involves a smelting chemical composition (mass percentage) consisting of the following elements: C 0.95%~1.00%, Si 0.67%~0.70%, Mn 0.85%~0.90%, P≤0.015%, S≤0.010%, Cr 0.35%~0.40%, V 0.07%~0.08%, with the remainder being Fe and other unavoidable impurities. The top layer 2 has a thickness of 105mm, the intermediate layer 3 has a thickness of 200mm, and the top layer 2, intermediate layer 3, and bottom layer 4 together form a stepped difference with a depth of 305mm. The first preset threshold is 22 tons, and the second preset threshold is 11 tons. Chemical analysis of the slag from the tundish impact zone covering agent of the above castings shows that the mass percentage of calcium fluoride and barium oxide originating from ladle slag in the slag is significantly reduced, with an average calcium fluoride content of 1.2% and an average barium oxide content of 0.36%. The weight of the slag residue was measured, and the weight of the residual steel was reduced to 575 kg / furnace.

[0062] Example 3:

[0063] The difference between this embodiment and Embodiment 1 is that the production of eutectoid rail steel involves a smelting chemical composition (mass percentage) consisting of the following elements: C 0.90%~0.96%, Si 0.64%~0.68%, Mn 0.750%~0.85%, P≤0.012%, S≤0.009%, Cr 0.30~0.35%, V 0.06%~0.08%, with the remainder being Fe and other unavoidable impurities. The top layer 2 has a thickness of 100mm, the intermediate layer 3 has a thickness of 200mm, and the top layer 2, intermediate layer 3, and bottom layer 4 together form a stepped difference with a depth of 300mm. The first preset threshold is 21 tons, and the second preset threshold is 10.5 tons. Chemical analysis of the slag from the tundish impact zone covering agent of the above castings shows that the mass percentage of calcium fluoride and barium oxide originating from ladle slag in the slag is significantly reduced, with an average calcium fluoride content of 1.02% and an average barium oxide content of 0.27%. The weight of the slag residue was measured, and the residual steel weight was reduced to 630 kg / furnace.

[0064] Comparative example:

[0065] A steel company uses a traditional flat-bottomed ladle (i.e., without a stepped bottom structure or a central groove) for continuous casting of heavy rail steel. Chemical composition analysis of the slag in the impact zone of the tundish from the tested heats revealed significantly higher levels of the characteristic components calcium fluoride and barium oxide originating from the ladle cover slag. The average calcium fluoride content was 2.10%, and the average barium oxide content was 0.57%, values ​​far exceeding those found in the embodiments of this invention (calcium fluoride ≈ 1.1-1.2%, barium oxide ≈ 0.31-0.36%). This indicates a significant slag runoff phenomenon at the end of the traditional flat-bottomed ladle casting process, with a large amount of ladle cover slag being incorporated into the tundish.

[0066] Meanwhile, the weighing statistics of the casting residue showed that the weight of the residual steel in a single heat fluctuated greatly, ranging from 800 to 2235 kg / heat, with an average of 1370 kg / heat.

[0067] The comparison between the above embodiments and comparative examples fully demonstrates that by adopting the stepped ladle bottom structure combined with the control method described in this invention, slag discharge control and residual steel reduction control at the end of each ladle casting process are achieved. By controlling the shape of the ladle bottom molten pool, the depth of the slag discharge molten pool is controlled, and the continuity of rotating flow is suppressed, thereby achieving large-scale ladle casting with minimal slag discharge and low steel consumption.

[0068] It should be noted that in this specification, relational terms such as first and second are used only to distinguish one entity from several other entities, and do not necessarily require or imply any such actual relationship or order between these entities.

[0069] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A device for reducing slag runoff from the ladle during the continuous casting process of heavy rail steel, characterized in that, include: A steel ladle shell (1) is connected to an insulated cover. The bottom of the steel ladle shell (1) is arranged from top to bottom as a top layer (2), a middle layer (3) and a bottom layer (4), forming a stepped structure. The middle layer (3) is provided with a groove (5). The depth of the groove (5) is equal to the thickness of the middle layer (3). A drain pipe (6) is provided at the center of the groove (5). The upper opening of the drain pipe (6) is connected to the groove (5), and the lower opening penetrates the bottom layer (4) and extends to the outside of the steel ladle shell (1). Weighing component and control unit, wherein the weighing component is used to monitor the total weight M of the remaining molten steel and slag in the ladle shell (1) in real time; when the total weight M drops to a first preset threshold, the control unit activates the slag detection component; when the total weight M further drops to a second preset threshold, the removal operation of the heat preservation ladle cover is performed; The shut-off assembly is installed inside the drain pipe (6). When the slag detection assembly detects that the proportion of molten slag in the molten steel reaches the preset threshold of molten slag, the control unit activates the shut-off assembly to close the outlet of the drain pipe (6).

2. The device for reducing slag runoff from the ladle during the continuous casting process of heavy rail steel according to claim 1, characterized in that, The thickness of the top layer (2) is 100-105mm, and its horizontal cross section is elliptical. The short axis of the ellipse is 4 / 3 times the bottom radius of the steel cladding shell (1), and the long axis is 1.18 times the short axis.

3. The device for reducing slag runoff from the ladle during the continuous casting process of heavy rail steel according to claim 2, characterized in that, The thickness of the intermediate layer (3) is 200-210mm, the groove (5) is circular, and the diameter of the groove (5) is 2 / 3 of the bottom radius of the steel cladding shell (1).

4. The device for reducing slag runoff from the ladle during the continuous casting process of heavy rail steel according to claim 3, characterized in that, The upper end face of the drain pipe (6) is flush with the upper surface of the bottom layer (4), and the top layer (2), the middle layer (3) and the bottom layer (4) together form a stepped difference with a depth of 300-310mm.

5. The device for reducing slag runoff from the ladle during the continuous casting process of heavy rail steel according to claim 1, characterized in that, The insulation cover adopts a double-layer high-temperature resistant structure, with an inner layer of ceramic fiber and an outer layer of heat-resistant steel plate.

6. The device for reducing slag runoff from the ladle during the continuous casting process of heavy rail steel according to claim 1, characterized in that, It also includes a temperature acquisition module, which includes multiple thermocouple sensors. The thermocouple sensors are embedded in the slag layer area of ​​the inner wall of the ladle shell (1) and are distributed at intervals along the height direction of the ladle shell (1). The thermocouple sensors are electrically connected to the control unit.

7. The device for reducing slag runoff from the ladle during the continuous casting process of heavy rail steel according to claim 1, characterized in that, The first preset threshold is 20-22 tons, and the second preset threshold is 10-11 tons.

8. The device for reducing slag runoff from the ladle during the continuous casting process of heavy rail steel according to claim 1, characterized in that, The slag detection component is an electromagnetic detection system, and the preset threshold for molten slag is 20% of the molten slag volume.

9. A method for controlling slag runoff in the continuous casting process of heavy rail steel, applied to the apparatus for reducing slag runoff in the continuous casting process of heavy rail steel as described in any one of claims 1 to 8, characterized in that, The control method includes the following steps: S1. During the casting process, the total weight M of the remaining molten steel and slag inside the ladle shell (1) is monitored in real time by the weighing component. S2: When the total weight M drops to the first preset threshold, the control unit activates the slag detection component to detect the slag ratio of the molten steel flowing out from the drain pipe (6) in real time. S3: When the total weight M further decreases to the second preset threshold, the control unit issues an instruction to remove the heat insulation cover on the top of the steel ladle shell (1) to increase the temperature gradient of the slag layer and increase the viscosity of the liquid slag at the steel slag interface. S4: When the slag detection component detects that the proportion of molten slag in the molten steel reaches the preset threshold, the control unit drives the shut-off plate component to close the outlet of the water pipe (6) and terminate the casting.

10. The control method according to claim 9, characterized in that, In step S4, the control unit triggers the shut-off component only when the slag detection component detects that the proportion of molten slag reaches or exceeds the preset threshold for molten slag in three consecutive samples.

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