CN103990787B - A kind of for removing the device and method of molten steel inclusion in continuous casting production - Google Patents

Abstract

The invention relates to a device and method for removing liquid steel inclusions in a continuous casting tundish, comprising a turbulence controller, an air curtain ventilation brick, a retaining wall and a retaining dam, and the air curtain ventilation brick (2) is located in the turbulence controller ( 1) and the retaining wall (3), fixed on the permanent lining at the bottom of the tundish, the horizontal distance a between the longitudinal centerline of the turbulence controller (1) and the air curtain permeable brick (2) is 400-600mm, and the air The horizontal distance b between the curtain ventilation brick (2) and the retaining wall (3) is 200-700 mm, and the horizontal distance c between the retaining wall (3) and the retaining dam (4) is 200-700 mm. The application of the present invention makes the continuous casting slab medium Inclusions with an effective diameter greater than 50 μm are basically removed, and the number of tiny inclusions with an equivalent diameter less than 50 μm in the continuous casting slab is reduced by more than 60% compared with the same period of the previous year compared with the tundish under the combination of turbulence controller, retaining wall and dam The settings in the package are reduced by more than 30% year-on-year under the conditions of use of turbulence controllers and air curtain ventilation bricks.

Description

A device and method for removing liquid steel inclusions in continuous casting tundish

technical field

The invention relates to a device and method for removing liquid steel inclusions in a continuous casting tundish, belonging to the technical field of iron and steel metallurgy continuous casting tundish technology.

Background technique

In the tundish of the continuous casting machine, a flow control device composed of a turbulent flow controller, a retaining wall and a dam is installed, which can change the running route of the molten steel in the tundish, prolong the residence time of the molten steel in the tundish, and promote the floating and melting of inclusions. The metallurgical function of removing and reducing the inclusions inside the slab and changing the shape of the inclusions. In recent years, in order to meet the requirements for the control of inclusions in the development and production of high-purity clean steel, the technology of continuous casting tundish air curtain retaining wall has been studied and applied, that is, the air curtain permeable brick is placed at the bottom of the tundish, and argon gas is blown in, and the argon gas is permeable. The air curtain retaining wall floats and forms a micro-bubble air curtain barrier. These micro-bubbles capture and float the inclusions, and then are absorbed by the slag layer to achieve the purpose of removing inclusions and purifying molten steel.

For example, Chinese patent document CN201603865U (application number: 201020116865.1) discloses a T-shaped tundish equipped with a flow control device. A T-shaped tundish adopting a "two walls and two dams" type flow control device, including a tundish, a shroud, first, second, third, and fourth water outlets, and a flow control device. The flow control device includes two Retaining wall and two retaining dams, the retaining walls are symmetrically arranged in the enclosure cavity between the second and third water outlets on both sides of the long nozzle, the peripheral part of the retaining wall is connected with the inner wall of the enclosure cavity, and the middle of the retaining wall There are diversion holes in the lower part of the retaining wall, and the two retaining dams are symmetrically arranged in the enclosure cavity between the first and second water outlets, and the third and fourth water outlets. The inner wall of the body cavity is connected. The T-shaped tundish of the utility model adopts a "two walls and two dams" type flow control device, which improves the flow form of molten steel in the tundish, prolongs the time for molten steel to reach the water outlet, promotes the floating and separation of inclusions, and evens the flow of molten steel. ingredients and temperature.

Chinese patent document CN101121199 (application number: 200710121680.2) discloses a method for removing non-metallic inclusions in the continuous casting tundish air curtain retaining wall, placing breathable bricks on the permanent layer of the tundish, connecting the argon blowing pipeline, and building the working layer. , it is required that the air-permeable surface of the breathable brick exposes the bottom of the tundish with a size of 0MM~40MM, blowing argon gas from the bottom of the tundish is conducive to the collision and growth of inclusion particles and removal; the floating air bubbles can capture inclusion particles and carry them up together , so that the floating speed of tiny inclusion particles is increased to the speed of air bubbles, which can completely or partially replace the original tundish retaining wall (dam), thereby reducing the inclusions brought into molten steel by retaining wall (dam) erosion , Effectively improve the purity of molten steel.

In the actual production process, after long-term production practice, it has been proved that the existing flow control device and the continuous casting tundish air curtain retaining wall technology have technical defects: (1) the continuous casting machine tundish is set by The combination of turbulence controller, retaining wall and retaining dam can only effectively remove inclusions with equivalent diameter greater than 50 μm, but cannot effectively remove tiny inclusions with equivalent diameter less than 50 μm; in the tundish of continuous casting machine The technical scheme of setting air curtain permeable bricks inside can only effectively remove tiny inclusions with equivalent diameters less than 50 μm, but cannot effectively remove inclusions with equivalent diameters greater than 50 μm; (2) The installation positions of existing air curtain permeable bricks are: Technical defect: The existing air curtain permeable brick replaces the dam or is installed in the pouring area between the dam and the upper nozzle of the tundish, and the actual application effect of effectively removing tiny inclusions with an equivalent diameter of less than 50 μm is poor; (3) In order to remove The effect of inclusions in molten steel requires that the bubbles produced by air curtain bricks have a small diameter and high density, but the slit air curtain bricks produced by the existing technology have large pores, generally with an equivalent diameter greater than 50 μm, resulting in The equivalent diameter of the bubbles is relatively large (measured by the water model experiment, the equivalent diameter of the bubbles is greater than 1.5mm) and the number is small, and the density of the bubbles forming the air curtain retaining wall is small, so the actual application effect of removing inclusions is not ideal.

Chinese patent document CN202779663U (application number: 201220454113.5) is a tundish flow control device, which includes a tundish and a turbulence controller. An upper retaining wall and a lower retaining wall are arranged symmetrically on the left and right sides of the turbulence controller respectively. The package is an open structure with an inverted trapezoidal cross-section, the lower retaining wall is an inverted trapezoidal body structure, and the vertical height of the lower end surface of the upper retaining wall is smaller than the vertical height of the end face of the lower retaining wall; A steel outlet is provided on the outside, and a row of air-permeable walls made of air-permeable bricks are arranged on the bottom wall of the inner cavity of the tundish between the steel outlet and the lower retaining wall. The tundish flow control device of the utility model utilizes a new type of turbulent flow controller installed at the bottom, and the injected molten steel forms two paths, which not only effectively prolongs its residence time in the tundish, but also facilitates the removal of inclusions, and makes The flow of molten steel is more gentle and orderly. However, this patent has the following disadvantages. Although the upper retaining wall and the lower retaining wall can remove a part of the inclusions with an equivalent diameter greater than 50 μm, the removal effect is not ideal, and the pores of the air curtain permeable brick are large, and the diameter of the argon bubbles produced is relatively large. It is rare, and the removal of inclusions with an equivalent diameter greater than 50 μm and inclusions with an equivalent diameter less than 50 μm is not ideal.

Contents of the invention

Aiming at the deficiencies of the prior art, the present invention provides a device and method for removing molten steel inclusions in the continuous casting tundish. The present invention optimizes the position of the flow control device and the air curtain permeable brick in the tundish, and the application effect is Significantly improved, the use of the device of the present invention enables the basic removal of inclusions with an equivalent diameter of greater than 50 μm in the continuous casting slab, and the number of tiny inclusions with an equivalent diameter of less than 50 μm in the continuous casting slab is higher than that of simply setting turbulence controllers, retaining walls, etc. in the tundish. The inclusions in the continuous casting slab produced by the dam retaining device are reduced by more than 60% year-on-year, which is more than 30% less than the inclusions in the continuous casting slab produced by the tundish simply setting the turbulence controller and the air curtain ventilation device.

Technical scheme of the present invention is as follows:

A device for removing liquid steel inclusions in a continuous casting tundish, including a turbulence controller (1), an air curtain permeable brick (2), a retaining wall (3) and a retaining dam (4), the turbulence controller is installed on The inner side of the working lining of the tundish wall in the impact area of the tundish injection, its longitudinal centerline coincides with the centerline of the long nozzle of the ladle, the two sides of the retaining wall are fixed on the working lining of the tundish wall, and the bottom end of the retaining dam is fixed on the On the bottom working lining of the tundish, the retaining wall is located between the turbulent flow controller and the retaining dam, and it is characterized in that the air curtain permeable brick (2) is located between the turbulent flow controller (1) and the retaining wall (3), And the bottom end is fixed on the permanent lining of the bottom of the tundish, the horizontal distance a between the longitudinal centerline of the turbulence controller (1) and the air curtain ventilation brick (2) is 400-600 mm, and the air curtain ventilation brick (2) and the air curtain ventilation brick (2) are The horizontal distance b of the retaining wall (3) is 200-700 mm, the horizontal distance c between the retaining wall (3) and the retaining dam (4) is 200-700 mm, and the horizontal distance d between the retaining dam and the upper nozzle of the tundish is 800-1200 mm, The retaining wall and the retaining dam are arranged alternately up and down, and the top of the air curtain permeable brick is lower than the bottom of the retaining wall or the top of the retaining dam.

Further preferably in the present invention, the horizontal distance between the longitudinal centerline of the turbulence controller (1) and the air curtain permeable brick (2) is 550-600mm, and the horizontal distance between the air curtain permeable brick (2) and the retaining wall (3) b is 600-700mm, and the horizontal distance c between the retaining wall (3) and the retaining dam (4) is 600-700mm.

The air curtain permeable brick (2) of the present invention is located between the turbulence controller (1) and the retaining wall (3), and is fixed on the permanent lining at the bottom of the tundish. The longitudinal centerline of the turbulence controller (1) is in line with the air The horizontal distance a of the air curtain brick (2) is 400-600mm, the horizontal distance b between the air curtain brick (2) and the retaining wall (3) is 200-700mm, and the horizontal distance between the retaining wall (3) and the retaining dam (4) The distance c is 200-700 mm, which is based on the task of the present invention: not only can effectively remove inclusions with an equivalent diameter greater than 50 μm, but also can effectively remove tiny inclusions with an equivalent diameter less than 50 μm, so that the equivalent diameter in the continuous casting slab is greater than 50 μm It is specially selected to improve the removal ability of molten steel inclusions in the tundish. It is obtained by those skilled in the art through long-term experiments. The present invention, due to the effect of the turbulence controller, can enter the tundish. The flow direction of molten steel changes and the flow rate decreases. The molten steel flows above the air curtain ventilation brick between the turbulence controller (1) and the retaining wall (3), and the air curtain ventilation brick blows out continuous and tight argon bubbles to form a strip air curtain barrier , the bar-shaped air curtain further reduces the flow rate of molten steel, prolongs the residence time of molten steel in the tundish, and improves the flow behavior of molten steel. At this time, the tiny inclusions with an equivalent diameter of less than 50 μm in molten steel are relatively active and dense The argon bubbles capture the tiny inclusions and some inclusions with an equivalent diameter greater than 50 μm float up, and are absorbed by the slag layer. The molten steel passes through the retaining wall, passes through the deflection and speed reduction of the retaining wall, and reaches the retaining dam, and a part of the molten steel turns over. Through the dam to form an upward flow stream, another part of the molten steel flows upward along the side wall to the surface at the junction of the dam and the side wall, and further removes inclusions with an equivalent diameter greater than 50 μm. The air curtain permeable brick and the retaining wall , The cooperation of the retaining dam basically removes the inclusions with an equivalent diameter greater than 50 μm.

The position of the air curtain permeable brick of the present invention, the distance between the air curtain permeable brick and the turbulence controller, and the distance from the retaining wall are obtained by those skilled in the art through long-term experiments, so that the equivalent diameter in molten steel is less than 50 μm. The number of tiny inclusions is more than 60% less than that of the liquid steel inclusions in the device where the turbulence controller, retaining wall and retaining dam are simply installed in the continuous casting tundish.

Preferably in the present invention, the air curtain permeable brick includes a permeable brick base and a permeable brick core. An air chamber is arranged in the permeable brick base. The part out of the breathable brick base is connected with a connecting joint, and the breathable brick base is provided with a breathable brick core embedding groove above the air chamber. The breathable brick core is embedded in the insert groove of the breathable brick base. The breathable brick The matrix is formed by vibration of magnesia castable, and the core of the breathable brick is formed by dispersed magnesia. The air-curtain air-permeable brick of the present invention has the advantages of high bubble density produced by the dispersion-type machine-pressed air-permeable brick, and has the advantage of low production cost of the cast-molded air-permeable brick.

Preferably in the present invention, the depth m of the bottom end of the air curtain permeable brick (2) embedded in the permanent lining (6) at the bottom of the tundish is 15-30mm, more preferably, 18-20mm. The bottom of the air-curtain ventilation brick (2) is embedded in the depth of the permanent lining (6) at the bottom of the tundish on the one hand to ensure continuous, dense and uniform argon blowing of the air-curtain ventilation brick; Easy to connect.

Preferably according to the present invention, the vertical stagger height n of the retaining wall and retaining dam is 100-150 mm, the thickness L of the retaining wall is 100-160 mm, and the thickness X of the retaining dam is 120-200 mm.

Preferably according to the present invention, the upper edge of the retaining wall is higher than the highest level (8) of molten steel normally poured in the tundish, but lower than the edge of the tundish.

Preferably according to the present invention, the turbulence controller of the present invention adopts a combined composite material structure, and the turbulence controller is assembled by the turbulence controller shell (15), the turbulence controller sleeve core (16), and the turbulence controller bottom plate (17). , apply an anti-oxidation paint coating (18) on the working surface, the turbulence controller sleeve core is located on the inner wall of the turbulence controller shell cavity, and the turbulence controller bottom plate is located at the bottom of the turbulence controller shell cavity, said The shell of the turbulence controller is molded by castable magnesium. The core of the turbulence controller is in the shape of a truncated cone with an upper diameter larger than that of the lower end. The core is made of magnesia castable and prepared by medium-temperature sintering process, and the bottom plate of the turbulence controller is formed by masonry of magnesia-carbon bricks.

Both the retaining wall (3) and the retaining dam (4) of the present invention are prepared by a medium-temperature firing process after the magnesium castable is poured and formed.

The present invention also provides a device for removing molten steel inclusions in a continuous casting tundish. The method for removing molten steel inclusions in a tundish includes the following steps:

1) During the baking process of the working lining of the tundish, the air curtain permeable brick (2) blows argon all the way, the argon pressure is controlled at 0.15-0.2MPa, and the flow rate is controlled at 10-20NL/min to prevent high-temperature oxidation and deformation of the argon pipeline ;

2) Argon is pre-blown in the tundish. 20-30 seconds before the ladle is poured, argon is blown into the sealed tundish through the air curtain permeable brick (2), and the argon gas is introduced to replace the air in the tundish. Control at 0.15~0.2MPa, flow control at 20~30NL/min;

3) When the ladle is poured until the liquid steel level in the tundish reaches the normal liquid level, the argon gas pressure of the air curtain permeable brick (2) is controlled at 0.15-0.2MPa, and the flow rate is controlled at 20-30NL/min;

4) For argon blowing on the normal pouring liquid steel surface in the tundish, the argon pressure of the air curtain permeable brick (2) is controlled at 0.2-0.3MPa, and the flow rate is controlled at 30-50NL/min.

Tests have proved that the pressure and flow rate can control the slight fluctuation of the liquid steel surface in the tundish, and can not blow off the slag surface.

5) When the pouring liquid level in the tundish is lower than the normal liquid level such as argon blowing for low steel liquid level in the tundish, ladle replacement, etc., turn down the argon gas, and control the argon gas pressure of the air curtain permeable brick (2) at 0.15~ 0.2MPa, the flow rate is controlled at 20-30NL/min;

6) After the tundish stops pouring, stop blowing argon on the air curtain permeable brick (2).

Beneficial effects of the present invention:

(1) The present invention locates the air curtain ventilation brick (2) between the turbulence controller (1) and the retaining wall (3), and the longitudinal centerline of the turbulence controller (1) and the air curtain ventilation brick (2) The horizontal distance a is 400-600mm, and the horizontal distance b between the air curtain permeable brick (2) and the retaining wall (3) is 200-700mm. After being applied to the slab continuous casting tundish, unexpected technical effects have been achieved: The inclusions with an equivalent diameter of more than 50 μm in the continuous casting slab produced by the device of the present invention are basically removed, and the number of tiny inclusions with an equivalent diameter of less than 50 μm in the continuous casting slab is less than that of the tundish. The inclusions in the continuous casting slab produced by the dam device are reduced by more than 60% year-on-year, which is more than 30% lower than the inclusions in the continuous casting slab produced by the tundish simply equipped with a turbulence controller and an air curtain ventilation device.

(2) The air curtain permeable brick (2) of the present invention is an embedded structure of secondary molding, which not only has the advantages of high air bubble density produced by the dispersion-type machine-pressed permeable brick, but also has the advantage of low production cost of the cast-molded permeable brick , Compared with machine-pressed air-permeable bricks, the production cost is reduced by more than 40% year-on-year.

Description of drawings

Fig. 1 is a schematic diagram of the overall structure of the device for removing inclusions in molten steel in a continuous casting tundish according to the present invention.

Fig. 2 is a schematic diagram of the structure of the air curtain permeable brick in the embodiment of the present invention, wherein, A is the front view of the air curtain permeable brick, and B is the side view of the air curtain permeable brick.

Fig. 3 is a schematic structural diagram of a turbulence controller in an embodiment of the present invention.

Fig. 4 is a schematic structural view of the retaining wall in an embodiment of the present invention, wherein, A is a front view of the retaining wall, and B is a side view of the retaining wall.

Fig. 5 is a schematic structural view of the retaining dam in an embodiment of the present invention, wherein, A is a front view of the retaining dam, and B is a side view of the retaining dam.

In the figure, 1. Turbulence controller; 2. Air curtain permeable brick; 3. Retaining wall; 4. Dam; 5. Working lining of tundish; 6. Permanent lining of tundish; The highest liquid level of molten steel for normal pouring; 9. Ladle long nozzle; 10. Breathable brick base; 11. Breathable brick core; 12. Air chamber; 13. Intake pipe; 14. Connecting joint; ; 16. Turbulence controller sleeve core; 17. Turbulence controller bottom plate; 18. Coating, 19. Longitudinal centerline of turbulence controller.

detailed description

The present invention will be further described below in conjunction with specific examples, but not limited thereto.

Example 1

A device for removing molten steel inclusions in a continuous casting tundish, the structure of which is shown in Figures 1-5, including a turbulence controller 1, an air curtain permeable brick 2, a retaining wall 3 and a dam 4, and the turbulence controller 1 Installed on the inner side of the working lining of the tundish wall in the injection impact area, its longitudinal centerline coincides with the centerline of the long nozzle 9 of the tundish. The bottom end of the dam is fixed on the working lining 5 at the bottom of the tundish, the retaining wall 3 is located between the turbulence controller 1 and the retaining dam 4, and the air curtain permeable brick 2 is located between the turbulence controller 1 and the retaining wall 3, And the bottom end is fixed on the permanent lining at the bottom of the tundish, the horizontal distance a between the longitudinal centerline of the turbulence controller 1 and the air curtain ventilation brick 2 is 550 mm, and the horizontal distance b between the air curtain ventilation brick 2 and the retaining wall 3 is 600mm, the horizontal distance c between the retaining wall 3 and the retaining dam 4 is 700mm, the horizontal distance d between the retaining dam and the upper nozzle of the tundish is 900mm, the retaining wall and retaining dam are arranged alternately up and down, and the top of the air curtain permeable brick Below the bottom of the retaining wall or the top of the retaining dam.

The air curtain permeable brick 2 includes a permeable brick base 10 and a permeable brick core 11. An air chamber 12 is arranged in the permeable brick base 10. One end of the air chamber 12 is connected with an air inlet pipe 13, and the air inlet pipe 13 is connected to the air chamber 12. Connected, the part of the air intake pipe 13 protruding from the breathable brick base 10 is connected with a connecting joint 14, and the breathable brick base 10 above the air chamber 12 is provided with a breathable brick core embedding groove, and the breathable brick core 11 is embedded in the breathable brick The matrix is embedded in the groove, the breathable brick matrix is formed by vibration of magnesia castable, and the core of the breathable brick is formed by dispersed magnesia. The depth m of the bottom end of the air curtain permeable brick 2 embedded in the permanent lining 6 at the bottom of the tundish is 15mm.

The vertical stagger height n of the retaining wall 3 and the retaining dam is 120 mm, the thickness L of the retaining wall is 100 mm, and the thickness X of the retaining dam is 120 mm. The upper edge of the retaining wall 3 is higher than the maximum liquid level 8 of molten steel normally poured in the tundish, but lower than the edge of the tundish.

The turbulence controller of the present invention adopts a combined composite material structure, and the turbulence controller is assembled by the turbulence controller shell 15, the turbulence controller sleeve 16, and the turbulence controller bottom plate 17, and the anti-oxidation paint coating is applied on the working surface 18. The core of the turbulence controller is located on the inner wall of the inner cavity of the turbulence controller housing, and the bottom plate of the turbulence controller is located at the bottom of the inner cavity of the turbulence controller housing. The core of the turbulence controller is in the shape of a truncated cone with the diameter of the upper end larger than that of the lower end, and the hollow in the middle is in the shape of a truncated cone with the diameter of the upper end smaller than the diameter of the lower end. The bottom plate of the turbulence controller is formed by masonry with magnesia carbon bricks.

Both the retaining wall 3 and the retaining dam 4 are prepared by a medium-temperature sintering process after the magnesium castable is poured and formed.

Embodiment 2,

The device for removing molten steel inclusions in the continuous casting tundish as described in Example 1, the difference is:

The horizontal distance a between the longitudinal centerline of the turbulence controller 1 and the air curtain permeable brick 2 is 600 mm, the horizontal distance b between the air curtain permeable brick 2 and the retaining wall 3 is 700 mm, and the horizontal distance c between the retaining wall 3 and the retaining dam 4 is 600mm, and the horizontal distance d between the retaining dam and the upper nozzle of the tundish is 1000mm.

The depth m of the bottom end of the air curtain permeable brick 2 embedded in the permanent lining 6 at the bottom of the tundish is 30mm.

Embodiment 3,

The device for removing molten steel inclusions in the continuous casting tundish as described in Example 1, the difference is:

The horizontal distance a between the central line of the turbulence controller 1 and the air curtain permeable brick 2 is 400mm, the horizontal distance b between the air curtain permeable brick 2 and the retaining wall 3 is 200mm, and the horizontal distance c between the retaining wall 3 and the retaining dam 4 is 200mm, and the horizontal distance d between the retaining dam and the upper nozzle of the tundish is 1200mm.

The depth m of the bottom end of the air curtain permeable brick 2 embedded in the permanent lining 6 at the bottom of the tundish is 18mm.

Embodiment 4,

A device for removing molten steel inclusions in a continuous casting tundish described in Embodiment 1. A method for removing molten steel inclusions in a tundish, comprising the following steps:

1) During the baking process of the working lining of the tundish, the air curtain permeable brick 2 blows argon all the way, the argon pressure is controlled at 0.15MPa, and the flow rate is controlled at 10NL/min to prevent the argon pipeline from being oxidized and deformed at high temperature;

2) Argon is pre-blown in the tundish. 20 seconds before the ladle is poured, argon is blown into the sealed tundish through the air curtain permeable brick 2, and the argon gas is introduced to replace the air in the tundish. The argon pressure is controlled at 0.15MPa , the flow rate is controlled at 20NL/min;

3) When the ladle is poured until the liquid steel level in the tundish reaches the normal liquid level, the argon gas pressure of the air curtain permeable brick 2 is controlled at 0.15MPa, and the flow rate is controlled at 20NL/min;

4) For argon blowing on the normal pouring liquid steel surface in the tundish, the argon pressure of the air curtain permeable brick (2) is controlled at 0.2MPa, and the flow rate is controlled at 30NL/min.

5) When the pouring liquid level in the tundish is lower than the normal liquid level such as argon blowing for low steel liquid level in the tundish, ladle replacement, etc., turn down the argon gas, and control the argon pressure of the air curtain permeable brick (2) at 0.15MPa , the flow rate is controlled at 20NL/min;

6) After the tundish stops pouring, stop blowing argon on the air curtain permeable brick (2).

Embodiment 5,

A device for removing molten steel inclusions in a continuous casting tundish described in Embodiment 1. A method for removing molten steel inclusions in a tundish, comprising the following steps:

1) During the baking process of the working lining of the tundish, the air curtain permeable brick 2 blows argon all the way, the argon pressure is controlled at 0.2MPa, and the flow rate is controlled at 20NL/min to prevent the argon pipeline from being oxidized and deformed at high temperature;

2) Argon is pre-blown in the tundish. 30 seconds before the ladle is poured, argon is blown into the sealed tundish through the air curtain permeable brick 2, and the argon gas is introduced to replace the air in the tundish. The argon pressure is controlled at 0.2MPa , the flow rate is controlled at 30NL/min;

3) When the ladle is poured until the liquid steel level in the tundish reaches the normal liquid level, the argon gas pressure of the air curtain permeable brick 2 is controlled at 0.2MPa, and the flow rate is controlled at 30NL/min;

4) For argon blowing on the normal pouring liquid steel surface in the tundish, the argon pressure of the air curtain permeable brick 2 is controlled at 0.3MPa, and the flow rate is controlled at 50NL/min.

5) When the pouring liquid level in the tundish is lower than the normal liquid level such as argon blowing for low steel liquid level in the tundish, ladle replacement, etc., turn down the argon gas, and control the argon pressure of the air curtain permeable brick (2) at 0.2MPa , the flow rate is controlled at 30NL/min;

6) After the tundish stops pouring, stop blowing argon on the air curtain permeable brick (2).

Comparative example 1

A device for removing liquid steel inclusions in a continuous casting tundish, including a turbulence controller, a retaining wall, and a retaining dam. The turbulence controller is installed on the inner side of the working lining of the tundish injection impact zone, and its centerline is in line with the The center line of the long nozzle of the bale coincides, the two ends of the retaining wall are fixed on the working lining of the tundish wall, the bottom end of the retaining dam is fixed on the working lining of the tundish bottom, and the upper edge of the retaining wall is higher than the tundish normal The poured molten steel has the highest liquid level, but is lower than the working surface of the smearing material at the overflow port of the tundish, and the retaining wall and retaining dam are arranged alternately up and down; the distance between the retaining wall and the turbulence controller is 550mm, and The horizontal distance is 600mm, and the horizontal distance between the retaining dam and the upper nozzle of the tundish is 1200mm.

Comparative example 2

A device for removing molten steel inclusions in a continuous casting tundish, including a turbulence controller and an air-curtain permeable brick. The turbulence controller is installed on the inner side of the working lining of the tundish injection impact area, and its longitudinal centerline is in line with the large The center line of the long nozzle 9 of the tundish coincides, the air curtain permeable brick is located between the turbulence controller and the upper nozzle of the tundish, and the bottom end is fixed on the permanent lining 6 at the bottom of the tundish. The horizontal distance between curtain ventilation bricks 2 is 550mm.

The air curtain permeable brick includes a permeable brick base and a permeable brick core. An air chamber is arranged in the permeable brick base. One end of the air chamber is connected with an air intake pipe. The air intake pipe communicates with the air chamber. Connecting the joint, the air-permeable brick core is provided with an embedding groove on the air-permeable brick base above the air chamber, the air-permeable brick core is embedded in the embedding groove of the air-permeable brick base, and the air-permeable brick base is formed by vibration of magnesia castable , The core of the breathable brick is made of dispersed magnesia. The depth m of the bottom end of the air curtain permeable brick embedded in the permanent lining of the tundish bottom is 15mm.

Comparative example 3

A device for removing liquid steel inclusions in a continuous casting tundish, including a turbulence controller 1, an air curtain permeable brick 2, a retaining wall 3 and a retaining dam 4, the turbulence controller 1 is installed in the injection impact area of the tundish The inner side of the wall working lining, its longitudinal centerline coincides with the centerline of the long nozzle 9 of the tundish, the retaining wall 3 is fixed on the working lining 5 of the tundish wall, and the retaining dam is located between the retaining wall 3 and the upper nozzle 7 of the tundish, And fixed on the working lining 5 at the bottom of the tundish, the retaining wall 3 and the dam 4 are arranged alternately up and down, the air curtain permeable brick 2 is located between the dam and the upper nozzle of the tundish, and fixed on the permanent lining 6 at the bottom of the tundish, The horizontal distance a between the longitudinal centerline of the turbulence controller 1 and the retaining wall is 400mm, the horizontal distance b between the retaining wall and the retaining dam is 600mm, the horizontal distance between the retaining dam and the air curtain brick is 700mm, and the air curtain is breathable The center horizontal distance between the brick and the upper nozzle of the tundish is 900mm.

Experimental example

The devices of Examples 1-3 and Comparative Examples 1-3 for removing liquid steel inclusions in the continuous casting tundish were applied to the single-strand wide slab continuous casting tundish in Laiwu Iron and Steel Group Yinshan Steel Co., Ltd. Steelmaking Plant for comparison Analysis, the steel type AH36, respectively take the cast slab samples, the size of the samples is 30mm in length and width, and the electron microscope is used for detection and analysis. The number of electrolytic inclusions in the field of view is shown in Table 1.

Table 1 Number of electrolytic inclusions in the field of view (unit: piece)

By comparing the data in Table 1, using the device of the present invention, in the field of view, the number of electrolytic inclusions with an equivalent diameter greater than 50 μm and an equivalent diameter of 40 to 50 μm in the continuous casting slab produced in Examples 1-3 of the present invention However, a small number of electrolytic inclusions with an equivalent diameter greater than 50 μm will appear in the continuous casting slab produced in Comparative Examples 1-3, and the number of electrolytic inclusions with an equivalent diameter of 40-50 μm is slightly more than that of the embodiment of the present invention. The continuous casting slab produced in Example 1-3; the number of electrolytic inclusions with an equivalent diameter less than 40 μm in the continuous casting slab produced in Comparative Example 1-3 is significantly more than that in the continuous casting slab produced in Example 1-3 of the present invention. The number of inclusions, so the device of the present invention can basically remove the inclusions with an equivalent diameter greater than 50 μm in the continuous casting slab, and the number of tiny inclusions with an equivalent diameter less than 50 μm in the continuous casting slab The inclusions in the continuous casting slab produced by the retaining wall and dam device decreased by 62.5% year-on-year, which was 33.3% lower than that of the continuous casting slab produced by the tundish simply setting the turbulence controller and the air curtain ventilation device. The inclusions in the continuous casting slab produced by the device installed between the dam and the upper nozzle of the tundish with air curtain permeable bricks decreased by 40% year-on-year.

Claims (8)

1. for removing a device for molten steel inclusion in continuous casting production, including turbulence inhibitor (1), air curtain air brick

null(2)、Barricade (3) and dam (4)，Turbulence inhibitor is arranged on the inner side of tundish beam impact zone containment wall working lining，Its longitudinal centre line overlaps with the centrage of big bag long nozzle，The two side ends of barricade is fixed on tundish containment wall working lining，The bottom of dam is fixed on tundish and is underwrited lining work，Described barricade is between turbulence inhibitor and dam，It is characterized in that，Air curtain air brick (2) is positioned between turbulence inhibitor (1) and barricade (3)，And bottom is fixed in permanent liner at the bottom of middle handbag，The horizontal range a of the longitudinal centre line of described turbulence inhibitor (1) and air curtain air brick (2) is 400～600mm，The horizontal range b of air curtain air brick (2) and barricade (3) is 200～700mm，The horizontal range c of barricade (3) and dam (4) is 200～700mm，The horizontal range d of dam and tundish upper nozzle is 800～1200mm，Described barricade and the upper and lower interlaced arrangement of dam，The top of the bottom lower than barricade, the top of described air curtain air brick or dam；Described air curtain air brick includes air brick matrix and air brick core body, it is provided with air chamber in air brick matrix, one end of air chamber is connected to air inlet pipe, air inlet pipe connects with in air chamber, air inlet pipe is stretched out the part of air brick matrix and is connected to jointing, air brick matrix is provided with air brick core body embedded groove above air chamber, described air brick core body embeds in the embedded groove of air brick matrix, described air brick matrix adopts castable vibration moulding, and air brick core body adopts the magnesia molding of diffusion-type.

2. according to claim 1 for removing the device of molten steel inclusion in continuous casting production, it is characterized in that, the horizontal range of the longitudinal centre line of described turbulence inhibitor (1) and air curtain air brick (2) is 550～600mm, the horizontal range b of air curtain air brick (2) and barricade (3) is 600～700mm, and the horizontal range c of barricade (3) and dam (4) is 600～700mm.

3. according to claim 1 for removing the device of molten steel inclusion in continuous casting production, it is characterised in that in the middle of the bottom embedment of described air curtain air brick (2), at the bottom of handbag, the degree of depth m of permanent liner (6) is 15～30mm.

4. according to claim 3 for removing the device of molten steel inclusion in continuous casting production, it is characterised in that in the middle of the bottom embedment of described air curtain air brick (2), at the bottom of handbag, the degree of depth m of permanent liner (6) is 18～20mm.

5. according to claim 1 for removing the device of molten steel inclusion in continuous casting production, it is characterised in that described barricade and the upper and lower staggered heights n of dam are 100～150mm, and the thickness L of barricade is 100～160mm, and the thickness X of dam is 120～200mm.

6. according to claim 1 for removing the device of molten steel inclusion in continuous casting production, it is characterised in that the most high liquid level (HLL) (8) of the molten steel that the upper edge of barricade is normally poured into a mould higher than tundish, but lower than middle handbag edge.

null7. according to claim 1 for removing the device of molten steel inclusion in continuous casting production，It is characterized in that，Turbulence inhibitor adopts combined material-structure，Turbulence inhibitor is by turbulence inhibitor shell (15)、Turbulence inhibitor set core (16)、Turbulence inhibitor base plate (17) assembles，Work surface is smeared antioxidation coating coating (18)，Turbulence inhibitor set core is positioned on the medial wall of turbulence inhibitor shell inner cavity，Turbulence inhibitor base plate is positioned at the bottom of turbulence inhibitor shell inner cavity，Described turbulence inhibitor shell adopts castable moulding by casting，Described turbulence inhibitor set core is the upper end diameter truncated cone more than lower end diameter，Central hollow is the upper end diameter truncated cone less than lower end diameter，Described turbulence inhibitor set core is that in adopting after castable moulding by casting, temperature firing process is prepared from，Described turbulence inhibitor base plate adopts magnesia carbon brick to build molding by laying bricks or stones；During barricade (3), dam (4) adopt after being castable moulding by casting, temperature firing process is prepared from.

8. the device for removing molten steel inclusion in continuous casting production described in claim 1 removes a method for molten steel inclusion in tundish, comprises the following steps:

1), in liner in dundish baking process, the omnidistance Argon of air curtain air brick (2), argon pressure controls at 0.15～0.2MPa, and flow-control is at 10～20NL/min, to prevent tunger tube road high-temperature oxydation, deformation；

2) pre-Argon in tundish, unwrap greatly water before 20 ~ 30s, by air curtain air brick (2) to blowing argon gas in the tundish sealed, pass into air in argon displacement tundish, argon pressure controls at 0.15～0.2MPa, and flow-control is at 20～30NL/min；

3) unwrapping greatly the Argon before watering to tundish molten steel face arrival normal level of liquid, the argon pressure of air curtain air brick (2) controls at 0.15～0.2MPa, and flow-control is at 20～30NL/min；

4) the normal Argon pouring into a mould molten steel face in tundish, the argon pressure of air curtain air brick (2) controls at 0.2～0.3MPa, flow-control at 30～50NL/min,

5) Argon in low molten steel face in tundish, when cast liquid level is lower than normal level of liquid in the tundish such as big bag replacing, turns argon down

Gas, the argon pressure of air curtain air brick (2) controls at 0.15～0.2MPa, and flow-control is at 20～30NL/min；

6), after tundish stops watering, air curtain air brick (2) Argon is stopped.