Molten steel guiding device for continuous casting crystallizer

Abstract

A molten steel flow guiding device for a continuous casting crystallizer is characterized in that a hollow molten steel flow guiding device with a rectangular tubular structure is arranged at a nozzle discharge port at the lower part of a submersed nozzle, and the molten steel flow guiding device is transversely inserted from the nozzle discharge port at one side of the submersed nozzle and then extends out from the nozzle discharge port at the other side of the submersed nozzle; the two ends of the molten steel guiding device are in a left-right balance state, and molten steel enters from the upper portion of the submersed nozzle, is shunted through the molten steel guiding device, flows out to the two sides through a lower molten steel outlet and enters a crystallizer. The device is simple in structure, low in cost and convenient for large-scale application. The device effectively prevents molten steel from splashing in the casting process of the crystallizer, is high in safety, can effectively prevent the molten steel from being hung at the corners of the crystallizer during casting of the crystallizer, and reduces the risk of steel leakage caused by hanging of the molten steel. Impact of molten steel is effectively relieved, impurities are prevented from being involved into a slab shell, accidents can be reduced, and slab quality is improved.

Description

Technical Field

[0001] The utility model relates to the field of iron and steel metallurgy, in particular to a device used in a continuous casting crystallizer for slab continuous casting of steel, capable of realizing molten steel diversion during pouring. Background Art

[0002] At present, in the slab continuous casting (abbreviated as: continuous casting) production process in the field of steel metallurgical production, a production technology is often used in which molten steel is transferred from a ladle into a tundish, and then enters the crystallizer through an immersed water nozzle through a stopper rod or slide control system installed on the tundish, and is continuously cooled to form a continuously cast slab.

[0003] Under the existing technology, in the process of molten steel entering the crystallizer through the submerged nozzle, the molten steel flows out from the discharge port at the lower end of the submerged nozzle. For slab continuous casting, the discharge port of the submerged nozzle is generally two symmetrical openings. The submerged nozzle is a refractory sleeve type structure for pouring installed at the bottom of the intermediate tank in the continuous casting equipment and inserted below the steel liquid level of the crystallizer. The main function of the submerged nozzle is to prevent secondary oxidation of the intermediate tank injection flow and splashing of molten steel. During implementation, the molten steel enters the crystallizer at a certain flow rate. When the discharge port is submerged in molten steel during the pouring process, the molten steel with a certain flow rate and flow rate is buffered by the submerged molten steel when it is ejected from the discharge port, which will not cause the molten steel to directly splash out of the crystallizer to cause a safety accident, nor will it cause the molten steel to stick to the crystallizer due to the ejection force and cause steel hanging and leakage accidents.

[0004] However, after a long period of production operation, on-site workers found that when the spout has not yet been submerged in molten steel, it is very easy for molten steel to splash directly out of the crystallizer during the pouring process, causing a safety accident, or the molten steel may stick to the crystallizer due to the jet force, causing steel hanging and leakage accidents.

[0005] In order to avoid the above-mentioned problems in the pouring process, the most traditional and common method is to place two splash guards near the short side copper plates of the crystallizer. The material of the splash guards is usually wood or metal. However, this method only has a slight blocking effect and cannot effectively solve the accidents caused by splashing of molten steel during pouring.

[0006] In the existing technology, patent application number CN201720850863.7 describes a continuous casting mold splash prevention device. Its overall structure is similar to a square metal box with an open bottom. This box is placed in the mold before pouring to prevent molten steel from splashing. However, after practice, it was found that this technology has shortcomings:

[0007] 1. Because the square metal box of this structure is close to the shape and size of the crystallizer, the molten steel cannot directly contact the crystallizer after flowing out, resulting in slow cooling and insufficient shell thickness;

[0008] 2. The square metal box of this structure needs to be produced additionally and is consumable, which greatly increases the production cost and is not suitable for large-scale continuous casting production.

[0009] 3. The square metal box of this structure is only suitable for use during the pouring phase when there is no molten steel in the mold. During the pouring phase when the tundish is replaced (called flying tundish in the industry, i.e., rapid tundish replacement), there is still molten steel in the mold. Placing this device at this time increases the risk to the operator and is unsafe. Moreover, the flying tundish process requires speed and accuracy, and placing this device will also increase the flying tundish time.

[0010] 4. The molten steel outlet of the square metal box of this structure is still facing the short side of the crystallizer, and the molten steel will still splash to the corner of the crystallizer and cause steel hanging;

[0011] 5. Under certain pouring conditions, it is necessary to close the steel flow and expose the outlet of the submerged nozzle to the steel liquid surface of the crystallizer. After checking the submerged nozzle and the outlet, or cleaning the outlet with oxygen, the device cannot be put into use when pouring again.

[0012] In summary, the existing technology is still difficult to avoid the molten steel splashing out of the crystallizer or the steel hanging and leakage accident caused by the molten steel sticking to the crystallizer due to the jet force, so a new type of molten steel diversion device is urgently needed to solve this problem. Utility Model Content

[0013] In order to solve the above problems, the utility model provides a molten steel diversion device for a continuous casting crystallizer, which is easy to operate and has a diversion structure designed for splash prevention when pouring in a continuous casting crystallizer. It can effectively avoid safety accidents caused by molten steel directly splashing out of the crystallizer during the pouring process, and can solve the problem of molten steel sticking to the crystallizer or splashing to the corners of the crystallizer due to the jet force, causing steel hanging and leakage.

[0014] The utility model is a molten steel guide device for a continuous casting crystallizer, and its specific structure is as follows:

[0015] A molten steel guide device for a continuous casting crystallizer, comprising an immersed nozzle, characterized in that:

[0016] The submerged nozzle is provided with a molten steel guide device at the nozzle outlet at the lower part thereof. Molten steel enters from the upper part of the submerged nozzle, is divided by the molten steel guide device, flows out to both sides, and enters the crystallizer.

[0017] The molten steel guide device is inserted horizontally from the nozzle outlet on one side of the immersion nozzle and then extends from the nozzle outlet on the other side. Both ends of the molten steel guide device are in a left-right balanced state.

[0018] According to the utility model, a molten steel guide device for a continuous casting crystallizer is characterized in that the molten steel guide device is specifically a hollow rectangular tubular structure, the shapes of its two ends are consistent with the opening shape of the nozzle outlet of the immersion nozzle, the wall thickness of the molten steel guide device is 2 to 5 mm, and the outer diameter of the molten steel guide device is 2 to 3 mm smaller than the size of the nozzle outlet.

[0019] The molten steel guide device is made of general carbon steel, or a material with a carbon content close to that of the cast steel. Its wall thickness is 2 to 5 mm depending on the superheat degree of pouring. The higher the superheat degree, the thicker the wall thickness. The outer diameter of the molten steel guide device is smaller than the nozzle outlet in order to form a certain gap for easy installation and to leave space for thermal expansion when heated.

[0020] According to the utility model, a molten steel guide device for a continuous casting crystallizer is characterized in that the molten steel guide device is provided with an installation positioning baffle on its upper part, and the installation positioning baffle is specifically a plate-shaped structural member that is welded and fixed in a vertical shape. When the molten steel guide device is horizontally inserted from the nozzle outlet at one end of the immersion nozzle, the installation positioning baffle clamps the outer wall of the outlet at that location to position the molten steel guide device.

[0021] According to the utility model, a molten steel guide device for a continuous casting crystallizer is characterized in that an upper molten steel injection port with a rectangular opening structure is provided on the upper part of the middle section of the molten steel guide device, and the upper molten steel injection port is opposite to the inner hole of the immersion nozzle, and the upper molten steel injection port is connected to the hollow interior of the molten steel guide device. The specific size of the upper molten steel injection port is the inner hole area of ​​the immersion nozzle plus half of the nozzle wall thickness.

[0022] From the size description of the upper molten steel injection port, it can be seen that it is slightly larger than the inner diameter of the immersion nozzle. Its purpose is to ensure that when the molten steel is poured from the inner hole of the immersion nozzle from above and passes through the upper molten steel injection port, its resistance is reduced.

[0023] According to the utility model, a molten steel guide device for a continuous casting crystallizer is characterized in that the lower part of the molten steel guide device is arranged horizontally at equal intervals and is symmetrically arranged on the left and right sides with lower molten steel flow outlets, and the total number of the lower molten steel flow outlets is 2, 4 or 6. The molten steel entering the internal space of the molten steel guide device flows out from these lower molten steel flow outlets and flows into the crystallizer.

[0024] According to a molten steel guide device for a continuous casting crystallizer of the utility model, the specific number of the lower molten steel outlets is related to the width of the crystallizer, which is specifically:

[0025] 1) When the mold width is ≤1000mm, the number of lower molten steel outlets is 2 openings;

[0026] 2) When the width of the crystallizer is 1000-1500 mm, the number of the lower molten steel outlet openings is 4;

[0027] 3) When the mold width is ≥1550mm, a structure with 6 lower molten steel outlets is adopted;

[0028] In addition, the total opening area of ​​the lower molten steel outflow outlet is larger than the total opening area of ​​the nozzle outlets on both sides of the submerged nozzle, preferably 2 to 3 times.

[0029] The design purpose here is to ensure that the area of ​​the lower molten steel flow outlet is larger than the total opening area of ​​the nozzle outlets on both sides, that is, to ensure that the molten steel flow rate is larger than that of the nozzle outlet, which can effectively reduce the impact of the molten steel, prevent inclusions from being drawn into the billet shell, reduce accidents and improve the quality of the slab.

[0030] According to the utility model, a molten steel guide device for a continuous casting crystallizer is characterized in that a molten steel buffer hole is provided at the lower part of the middle section of the molten steel guide device, the molten steel buffer hole is connected to the hollow interior of the molten steel guide device, the molten steel buffer hole is opposite to the lower part of the upper molten steel injection port, and its shape and opening area are equal to those of the upper molten steel injection port.

[0031] According to the utility model, a molten steel guide device for a continuous casting crystallizer is characterized in that the shape of the molten steel buffer hole can also be circular, and its opening area is also equal to the opening area of ​​the upper molten steel injection port.

[0032] The purpose of the design here is that the molten steel buffer hole buffers the molten steel injected into the molten steel guide device through the upper molten steel injection port, which can effectively prevent the molten steel from hanging on the corner of the crystallizer when the crystallizer is poured, thereby reducing the risk of steel leakage caused by hanging steel.

[0033] The following beneficial effects are achieved by using the molten steel guide device for a continuous casting crystallizer of the utility model:

[0034] 1. The molten steel guide device for a continuous casting mold of the utility model has a simple structure, low cost, and is convenient for large-scale application;

[0035] 2. The molten steel guide device for a continuous casting mold of the utility model can decompose the large steel flow coming out of the discharge port into small steel flows, which can effectively avoid the splashing of molten steel during the pouring process of the mold. It is highly safe and can effectively prevent the molten steel from hanging on the corners of the mold during the pouring process, reducing the risk of steel leakage caused by hanging steel.

[0036] 3. During the pouring process, the molten steel flows directly downward into the mold through the molten steel guide device for a continuous casting mold of the utility model. The opening area of ​​the molten steel outlet is larger than the total area of ​​the outlets on both sides of the submerged nozzle, which effectively reduces the impact of the molten steel and prevents inclusions from being drawn into the slab shell, thereby reducing accidents and improving the quality of the slab.

[0037] 4. The utility model is a molten steel guide device for a continuous casting mold. It is easy to operate and only needs to be inserted into the discharge port before pouring, which greatly saves pouring time. After using the utility model, there is no need to apply sealant to the corners of the mold before pouring, and there is no need to place a splash plate when the tundish is flying, which further reduces process time and production costs.

[0038] 5. The molten steel guide device for a continuous casting crystallizer of the utility model can quickly melt into the molten steel after the molten steel is poured and submerged in the discharge port, without the risk of blocking the water outlet. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a specific implementation effect diagram of a molten steel guide device for a continuous casting crystallizer of the utility model;

[0040] Figure 2 This is a schematic diagram of the specific structure of a molten steel guide device for a continuous casting crystallizer of the utility model;

[0041] Figure 3 This is a bottom view of the specific structure of a molten steel guide device for a continuous casting crystallizer of the utility model.

[0042] In the figure: 1-immersed nozzle, 1a-nozzle outlet, 2-molten steel guide device, 3-installation positioning baffle, 4-upper molten steel injection port, 5-lower molten steel flow outlet, 6-molten steel buffer hole. DETAILED DESCRIPTION

[0043] The following further describes the technical means, creative features, objectives and effects achieved by the molten steel guide device for a continuous casting crystallizer of the present invention in combination with the accompanying drawings and embodiments.

[0044] Example

[0045] like Figures 1 to 3 As shown, a molten steel guide device for a continuous casting crystallizer includes an immersion nozzle 1. A molten steel guide device 2 is provided at the nozzle outlet 1a at the lower portion of the immersion nozzle. Molten steel enters from the upper portion of the immersion nozzle, is divided by the molten steel guide device, flows out to both sides, and enters the crystallizer.

[0046] The molten steel guide device 2 is inserted horizontally from the nozzle outlet 1a on one side of the immersion nozzle 1 and then extends from the nozzle outlet on the other side. Both ends of the molten steel guide device are in a left-right balanced state.

[0047] The molten steel guide device 2 is specifically a hollow rectangular tubular structure, the shapes of its two ends are consistent with the opening shape of the nozzle outlet 1a of the submerged nozzle 1, the wall thickness of the molten steel guide device is 2 to 5 mm, and the outer diameter of the molten steel guide device is 2 to 3 mm smaller than the size of the nozzle outlet.

[0048] The molten steel guide device 2 is provided with an installation positioning baffle 3 on its upper part. The installation positioning baffle is specifically a plate-like structural member that is welded and fixed in a vertical shape. When the molten steel guide device is horizontally inserted from the nozzle outlet 1a at one end of the immersion nozzle 1, the installation positioning baffle clamps the outer wall of the outlet at that location to position the molten steel guide device.

[0049] An upper molten steel injection port 4 with a rectangular opening structure is provided at the upper part of the middle section of the molten steel guide device 2. The upper molten steel injection port is opposite to the inner hole of the immersion nozzle, and the upper molten steel injection port is connected to the hollow interior of the molten steel guide device. The specific size of the upper molten steel injection port is the inner hole area of ​​the immersion nozzle plus half of the nozzle wall thickness.

[0050] The lower part of the molten steel guide device 2 is provided with lower molten steel flow outlets 5 which are arranged horizontally at equal intervals and symmetrically on the left and right. The total number of the lower molten steel flow outlets is 2, 4 or 6. The molten steel entering the internal space of the molten steel guide device flows out from these lower molten steel flow outlets and flows into the crystallizer.

[0051] The specific number of the lower molten steel outlets 5 is related to the width of the crystallizer, which is specifically:

[0052] 1) When the mold width is ≤1000mm, the number of lower molten steel outlets is 2 openings;

[0053] 2) When the width of the crystallizer is 1000-1500 mm, the number of the lower molten steel outlet is 4 openings (such as Figure 1 and Figure 3 As shown, in this embodiment, there are 4);

[0054] 3) When the mold width is ≥1550mm, a structure with 6 lower molten steel outlets is adopted;

[0055] In addition, the total opening area of ​​the lower molten steel outflow port is larger than the total opening area of ​​the nozzle outlets 1a on both sides of the submerged nozzle 1, and is preferably 2 to 3 times larger.

[0056] A molten steel buffer hole 6 is opened at the lower part of the middle section of the molten steel guide device 2, which is connected to the hollow interior of the molten steel guide device. The molten steel buffer hole is opposite to the lower part of the upper molten steel injection port 4, and its shape and opening area are equal to those of the upper molten steel injection port.

[0057] The shape of the molten steel buffer hole 6 can also be circular (such as Figure 3 As shown, it is circular in this embodiment), and its opening area is also equal to the opening area of ​​the upper molten steel injection port 4.

[0058] The specific use process of the molten steel guide device for a continuous casting crystallizer of the utility model is as follows:

[0059] 1. Before pouring, preheat the molten steel guide device 2 and control the temperature to no more than 800 degrees to prevent deformation (it can also be used directly without preheating);

[0060] 2. When the tundish is preheated, the molten steel guide device 2 is inserted horizontally along the nozzle outlet 1a on one side of the submerged nozzle 1 until the installation positioning baffle 3 is stuck to the outer wall of the outlet at that location. The molten steel guide device is then extended from the nozzle outlet on the other side. At this time, the two ends of the molten steel guide device are in a left-right balanced state.

[0061] 3. Move the tundish to the top of the crystallizer, confirm the positioning of the submerged nozzle, and then lower it into the crystallizer;

[0062] 4. When the molten steel level in the tundish rises to a state ready for pouring, the stopper or slide is opened, and the molten steel flows into the submerged nozzle 1 and enters the molten steel guide device 2 from the upper molten steel inlet 4 above the middle section. After being divided by the guide device, the molten steel flows out from the lower molten steel outlets 5 opened at the bottom and evenly enters the crystallizer;

[0063] 5. When the molten steel rises in the crystallizer and submerges the discharge port, the molten steel guide device 2 automatically melts due to its material.

[0064] The utility model discloses a molten steel guide device for a continuous casting crystallizer with a simple structure, low cost, and convenient for large-scale application. The utility model can decompose a large steel flow coming out of the discharge port into small steel flows, which can effectively avoid the splashing of molten steel during the pouring process of the crystallizer. It has high safety and can effectively prevent the molten steel from hanging on the corner of the crystallizer when the crystallizer is poured, thereby reducing the risk of steel leakage caused by hanging steel. During the pouring process of the utility model, the molten steel flows directly downward into the crystallizer through the guide device. The opening area of ​​the molten steel flow outlet is larger than the total area of ​​the discharge ports on both sides of the immersion nozzle, which effectively reduces the impact of the molten steel and prevents inclusions from being drawn into the billet shell, thereby reducing accidents and improving the quality of the slab. The utility model is easy to operate. Before pouring, it only needs to be inserted into the discharge port, which greatly saves the pouring time. After using the utility model, there is no need to apply sealant on the corners of the crystallizer before pouring, and there is no need to place a splash plate when the tundish is flying, which further reduces the process time and production cost. In addition, after the molten steel submerges the discharge port during pouring, the utility model can quickly melt into the molten steel without the risk of blocking the water outlet.

[0065] It should be noted that in the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as a limitation on the present invention.

[0066] Those skilled in the art should recognize that the above embodiments are merely intended to illustrate the present application and are not intended to limit the present application. As long as they are within the spirit of the present application, any changes or modifications to the above embodiments will fall within the scope of the claims of the present application.

Claims

1. A molten steel guide device for a continuous casting crystallizer, comprising an immersion nozzle (1), characterized in that: The submerged nozzle (1) is provided with a molten steel guide device (2) at the nozzle outlet (1a) at its lower portion. Molten steel enters from the upper portion of the submerged nozzle, is divided by the molten steel guide device, flows out to both sides, and enters the crystallizer. The molten steel guide device (2) is inserted horizontally from the nozzle outlet (1a) on one side of the immersion nozzle (1) and then extends from the nozzle outlet on the other side. Both ends of the molten steel guide device are in a left-right balanced state.

2. A molten steel guide device for a continuous casting mold according to claim 1, characterized in that: The molten steel guide device (2) is specifically a hollow rectangular tubular structure, the shapes of its two ends are consistent with the opening shape of the nozzle outlet (1a) of the immersion nozzle (1), the wall thickness of the molten steel guide device is 2 to 5 mm, and the outer diameter of the molten steel guide device is 2 to 3 mm smaller than the size of the nozzle outlet.

3. The molten steel guide device for a continuous casting mold according to claim 1, characterized in that: The molten steel guide device (2) is provided with an installation positioning baffle (3) on its upper portion. The installation positioning baffle is specifically a plate-shaped structural member that is welded and fixed in a vertical shape. When the molten steel guide device is horizontally inserted from the nozzle outlet (1a) at one end of the immersion nozzle (1), the installation positioning baffle clamps the outer wall of the outlet at that location to position the molten steel guide device.

4. A molten steel guide device for a continuous casting mold according to claim 1, characterized in that: An upper molten steel injection port (4) with a rectangular opening structure is provided on the upper portion of the middle section of the molten steel guide device (2). The upper molten steel injection port is directly opposite to the inner hole of the immersion nozzle, and the upper molten steel injection port is connected to the hollow interior of the molten steel guide device. The specific size of the upper molten steel injection port is the inner hole area of ​​the immersion nozzle plus half of the nozzle wall thickness.

5. The molten steel guiding device for a continuous casting mold according to claim 1, characterized in that: The lower part of the molten steel guide device (2) is provided with lower molten steel flow outlets (5) arranged horizontally at equal intervals and symmetrically on the left and right sides. The total number of the lower molten steel flow outlets is 2, 4 or 6. The molten steel entering the internal space of the molten steel guide device flows out from these lower molten steel flow outlets and flows into the crystallizer.

6. A molten steel guide device for a continuous casting mold according to claim 5, characterized in that: The specific number of the lower molten steel outlets (5) is related to the width of the crystallizer, which is specifically: 6.1) When the mold width is ≤1000mm, the number of lower molten steel outlets is 2 openings; 6.2) When the mold width is 1000-1500 mm, the number of lower molten steel outlets is 4 openings; 6.3) When the mold width is ≥1550mm, a structure with 6 lower molten steel outlets is adopted; In addition, the total opening area of ​​the lower molten steel outlet is larger than the total opening area of ​​the nozzle outlets (1a) on both sides of the submerged nozzle (1).

7. The molten steel guiding device for a continuous casting mold according to claim 1, characterized in that: A molten steel buffer hole (6) is provided at the lower portion of the middle section of the molten steel guide device (2), which is connected to the hollow interior of the molten steel guide device. The molten steel buffer hole is directly opposite to the lower portion of the upper molten steel injection port (4), and its shape and opening area are equal to those of the upper molten steel injection port.

8. A molten steel guiding device for a continuous casting mold according to claim 7, characterized in that: The shape of the molten steel buffer hole (6) can also be circular, and its opening area is also equal to the opening area of ​​the upper molten steel injection port (4).

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