A kind of ladle bottom blowing gas's air permeation device and ladle

Abstract

The application discloses a kind of steel ladle bottom blowing gas's air-permeable device and steel ladle, it is related to molten steel refining technical field, including seat brick, at least two groups of installation channels are opened in seat brick inside and pass through, two groups of installation channels inside are provided with air-permeable brick assembly, seat brick is used to install in the bottom of steel ladle, wherein, air-permeable brick assembly includes at least two first air-permeable module and second air-permeable module along axial superposition, first air-permeable module is set in the lower of second air-permeable module, and air chamber layer is arranged between first air-permeable module and second air-permeable module.Spiral distribution's guide vane makes gas that flows through air chamber obtain circumferential rotation component, and air current forms certain vortex effect when entering first air-permeable module, and this air current with rotation characteristics is sprayed after working end surface of air-permeable brick, can drive molten steel produce horizontal direction's tangential motion, and form compound flow field with the transverse flow brought by oblique installation, further enhance the stirring effect and inclusion removal efficiency of molten steel.

Description

Technical Field

[0001] This invention relates to the field of steel refining technology, specifically to a gas permeation device for bottom blowing of a steel ladle and a steel ladle. Background Technology

[0002] Bottom blowing in steel ladles is a process in which inert gases are blown into the bottom of a steel ladle, and it is an important step in steel smelting. By bottom blowing argon or other inert gases, the molten steel is made to circulate within the ladle, promoting the material conversion between steel and slag, and making the composition and substances of the molten steel more uniform. In addition, the bottom-blown gas can cause inclusions in the molten steel to gather and float to the surface, thereby improving the purity of the molten steel. It also helps to accelerate the deoxidation and decarburization reactions of the molten steel, improving the reaction efficiency.

[0003] Currently, when blowing air into a ladle using permeable bricks, the permeable bricks are typically installed vertically in the base brick, which is then installed at the bottom of the ladle. Because the permeable bricks are installed vertically, the gas passing through them is blown into the molten steel perpendicular to the bottom of the ladle. This results in insufficient mixing of the molten steel at the edges of the ladle, affecting the mixing effect, leading to low refining efficiency, incomplete removal of inclusions, and the permeable bricks being susceptible to thermal shock damage and having a short service life. To address these problems, a permeable device for bottom blowing of the ladle and a ladle are proposed as solutions. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the present invention provides a venting device and a ladle for bottom blowing of gas into a steel ladle. This solves the problem that in current methods of blowing gas into a steel ladle using venting bricks, the venting bricks are typically installed vertically in a base brick, which is then installed at the bottom of the ladle. Because the venting bricks are installed vertically, the gas passing through them is blown into the molten steel in a direction perpendicular to the bottom of the ladle. This results in insufficient agitation of the molten steel at the edges of the ladle, affecting the agitation effect, leading to low refining efficiency, incomplete removal of inclusions, and the venting bricks being easily damaged by thermal shock, resulting in a short service life.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a venting device for bottom blowing of a steel ladle, comprising a seat brick, wherein at least two sets of installation channels are provided through the seat brick, and venting brick assemblies are provided inside both sets of installation channels. The seat brick is used to install at the bottom of the steel ladle. The venting brick assembly comprises at least two first venting modules and second venting modules stacked along the axial direction. The first venting module is located below the second venting module. An air chamber layer is provided between the first venting module and the second venting module. The air chamber layer is enclosed by refractory material, and a gas buffer space is formed inside the air chamber layer that connects the first venting module and the second venting module.

[0006] Preferably, the first ventilated module is located at the end away from the inner wall of the ladle, and the second ventilated module is located at the end closer to the inside of the ladle. The first ventilated module and the second ventilated module are interconnected through the gas buffer space of the air chamber layer.

[0007] Preferably, the first ventilated module has an air collection chamber at its lower part, and at least eight sets of first ventilation channels extending axially are provided inside the first ventilated module. The lower end of the first ventilation channel is connected to the air collection chamber. An air inlet pipe interface is fixedly connected to the middle of the bottom surface of the first ventilated module. A high-pressure air pipe for connecting to an external air supply system is fixedly connected to the end of the air inlet pipe interface away from the first ventilated module. A flow control valve is installed on the high-pressure air pipe.

[0008] Preferably, the gas chamber layer is provided with at least six sets of guide vanes arranged circumferentially, and the guide vanes are spirally distributed to generate a circumferential rotation component in the gas flowing through the gas buffer space.

[0009] Preferably, the bottom surface of the second ventilation module has an air inlet, the interior of the second ventilation module has at least eight sets of second ventilation channels, the top of the second ventilation module has an exhaust chamber, the second ventilation channels are used to connect the upper exhaust chamber and the lower air inlet, and the at least eight sets of second ventilation channels are arranged in a radial spiral.

[0010] Preferably, a cover plate is fixedly connected above the second ventilation module. The top working end face of the cover plate is provided with a plurality of slits distributed radially. The slits are connected to the exhaust chamber. The width of the slits is 0.08 mm to 0.25 mm.

[0011] Preferably, the height of the first breathable module along the axial direction is greater than the height of the second breathable module along the axial direction, and the ratio of the height of the first breathable module to the height of the second breathable module is 2:1 to 5:1.

[0012] Preferably, a refractory filling layer is provided between the outer wall of the permeable brick assembly and the inner wall of the installation channel. The thickness of the refractory filling layer is 5mm to 15mm. The end of the installation channel near the inside of the ladle is inclined relative to the horizontal plane, with an inclination angle of 10° to 20°.

[0013] Preferably, an annular protective layer is provided between the working end face of the second ventilated module and the upper end face of the seat brick, and the annular protective layer is made of a refractory material with better thermal shock resistance than the second ventilated module.

[0014] On the other hand, a steel ladle is also provided, including a steel ladle body and a bottom-blowing ventilation device as described above, which is installed at the bottom of the steel ladle body.

[0015] Compared with the prior art, the advantages of the present invention are as follows: 1. By transforming the traditional integrated permeable brick into a combined structure of multiple permeable modules stacked axially, and setting air chamber layers between adjacent modules, a hierarchical configuration of the permeability function is achieved. When the first permeable module near the working end of the molten steel experiences blockage or performance degradation due to corrosion, penetration, or oxygen burn-off, the airflow can still be redistributed through the air chamber layers to the unblocked channels in the first permeable module, or continue to be blown out through the overall permeable structure of the first permeable module. This effectively delays the overall failure time of the permeable brick and significantly extends the service life of the permeable device.

[0016] 2. The airflow needs to be deflected and adjusted within the gas chamber layer before it can continue to be transported upwards. This allows the gas to undergo a brief buffering and redistribution process within the gas chamber layer, preventing the airflow from directly impacting the local area of ​​the upper permeable module and reducing the uneven scouring of the working end face by the airflow. At the same time, it allows the gas from different lower channels to be fully mixed within the gas chamber layer before entering the upper layer, improving the uniformity of the gas distribution. Furthermore, spirally distributed guide vanes are set within the gas chamber layer, giving the gas flowing through the gas chamber a circumferential rotation component. When the airflow enters the first permeable module, it forms a certain vortex effect. This airflow with rotational characteristics, after being ejected from the working end face of the permeable brick, can drive the molten steel to generate a horizontal tangential motion. This, combined with the lateral flow caused by the inclined installation, forms a composite flow field, further enhancing the stirring effect of the molten steel and the removal efficiency of inclusions. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the ventilation device for bottom air blowing in a steel ladle, as shown in an embodiment of the present invention. Figure 2 This is a cross-sectional view of the air-permeable device for bottom blowing of a steel ladle, as shown in an embodiment of the present invention. Figure 3 This is a schematic diagram of the permeable brick component structure of the permeable device for bottom air blowing in a steel ladle, as shown in an embodiment of the present invention. Figure 4 This is a cross-sectional view of the first breathable module shown in an embodiment of the present invention; Figure 5 This is a schematic diagram of the air chamber layer structure shown in an embodiment of the present invention; Figure 6 This is a schematic diagram of the structure of the second breathable module shown in an embodiment of the present invention; Figure 7 This is a cross-sectional view of the second breathable module shown in an embodiment of the present invention; Figure 8 This is a perspective view of the second breathable module shown in an embodiment of the present invention; Figure 9 This is a schematic diagram of a half-section of the ladle body as shown in an embodiment of the present invention.

[0018] The numbers on the map are: 1. Sealing brick; 2. Permeable brick assembly; 201. First permeable module; 202. Air collection chamber; 203. First ventilation channel; 204. Air inlet pipe interface; 205. High-pressure air pipe; 206. Flow control valve; 207. Air chamber layer; 208. Guide vane; 209. Second permeable module; 210. Cover plate; 211. Air inlet; 212. Second ventilation channel; 213. Exhaust chamber; 214. Slit; 3. Steel ladle body; 4. Installation channel; 5. Refractory filling layer. Detailed Implementation

[0019] In the description of this invention, it should be noted that the terms "front", "up", "down", "left", "right", "vertical", "horizontal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0020] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0021] Reference Figures 1-9 As shown, a venting device for bottom blowing of a steel ladle includes a seat brick 1. At least two sets of installation channels 4 are formed through the seat brick 1, and each set of installation channels 4 contains a venting brick assembly 2. The seat brick 1 is used to install on the bottom of the steel ladle. The venting brick assembly 2 includes at least two axially stacked first venting modules 201 and second venting modules 209. The first venting module 201 is located below the second venting module 209. An air chamber layer 207 is provided between the first venting module 201 and the second venting module 209. The air chamber layer 207 is enclosed by refractory material and forms a connection between the first venting module 201 and the second venting module 209. The gas buffer space of module 209, the first ventilated module 201, the second ventilated module 209 and the gas chamber layer 207 are squeezed together by their own weight and the surrounding refractory mortar. In this embodiment, the seat brick 1 is made of high alumina refractory brick, and the inner wall is ground to facilitate the installation of the ventilated brick assembly 2 and the filling of the refractory filling layer 5; the first ventilated module 201 and the second ventilated module 209 are both made of corundum refractory material, and the gas chamber layer 207 is surrounded by mullite refractory material; the refractory mortar is made of high alumina refractory mortar, with a room temperature bonding strength ≥15MPa, ensuring that the three are tightly bonded, with no gas leakage, and the bonding gap squeezed together by their own weight is ≤0.5mm.

[0022] In this embodiment, the first venting module 201 is located at the end away from the inner wall of the ladle, and the second venting module 209 is located at the end closer to the inside of the ladle. The first venting module 201 and the second venting module 209 are interconnected through the gas buffer space of the gas chamber layer 207. The end of the second venting module 209 closer to the inside of the ladle is higher than the upper surface of the seat brick 1 to ensure smooth exhaust and prevent molten steel from directly corroding the connection between the seat brick 1 and the venting module. The gas buffer space can achieve sufficient buffering and diversion of gas, ensuring that gas enters the second venting module 209 evenly, and there are no steps or burrs at the connection.

[0023] In this embodiment, a gas collection chamber 202 is provided at the lower part of the first ventilation module 201. At least eight sets of first ventilation channels 203 extending axially are provided inside the first ventilation module 201. The lower ends of the first ventilation channels 203 are connected to the gas collection chamber 202. An air inlet interface 204 is fixedly connected to the middle of the bottom surface of the first ventilation module 201. A high-pressure air pipe 205 for connecting to an external air supply system is fixedly connected to the end of the air inlet interface 204 away from the first ventilation module 201. A flow control valve is installed on the high-pressure air pipe 205. 206. The gas collecting chamber 202 is cylindrical with a smooth inner wall, enabling uniform gas collection; the first ventilation channel 203 is evenly distributed in a ring shape, with no blockages or cracks on the inner wall; the air inlet pipe interface 204 is made of heat-resistant stainless steel and is sealed to the first ventilation module 201 with refractory mortar; the high-pressure gas pipe 205 is made of high-temperature resistant stainless steel, with a working pressure range of 0.3MPa-1.2MPa and a high temperature resistance of ≥600℃; the flow control valve 206 is a manual + automatic dual-control valve with an adjustment accuracy of 0.01m. 3 / min, which can precisely control the blowing flow rate and adapt to different steel refining needs.

[0024] In this embodiment, at least six sets of guide vanes 208 are arranged circumferentially within the gas chamber layer 207. The guide vanes 208 are spirally distributed to generate a circumferential rotation component in the gas flowing through the gas buffer space. Specifically, the guide vanes 208 are constructed as follows: multiple vanes are evenly arranged circumferentially along the gas chamber layer 207, each vane is spirally distributed, that is, it has a fixed tilt angle relative to the radial direction of the cylindrical gas chamber layer 207. The vane tilt angle is between 20° and 45°, and all vanes have the same tilt direction. Together, they cause the gas in the gas chamber layer 207 to rotate circumferentially, just like the water flow in the inner drum of a washing machine. After being guided, the circumferential rotation speed of the gas is 1.5m / s to 3.0m / s, which can make the gas evenly dispersed to each of the second ventilation channels 212 of the second ventilation module 209, avoiding excessive local gas flow velocity that could cause molten steel to backflow.

[0025] In this embodiment, the second ventilation module 209 has an air inlet 211 on its bottom surface, at least eight sets of second ventilation channels 212 inside the second ventilation module 209, and an exhaust chamber 213 on its top. The second ventilation channels 212 are used to connect the upper exhaust chamber 213 and the lower air inlet 211, and the at least eight sets of second ventilation channels 212 are arranged in a radial spiral. The air inlet 211 is annular and precisely docks with the gas buffer space of the air chamber layer 207. The spiral direction of the second ventilation channels 212 is consistent with the rotation direction of the guide vanes 208. The exhaust chamber 213 is annular groove-shaped, which can realize secondary gas diversion and ensure that the gas is evenly discharged through the slit 214 of the cover plate 210. The inner wall of the exhaust chamber 213 is polished to reduce gas retention.

[0026] In this embodiment, a cover plate 210 is fixedly connected above the second ventilation module 209. The top working end face of the cover plate 210 is provided with several radially distributed slits 214. The slits 214 are connected to the exhaust chamber 213. The width of the slits 214 is 0.08mm to 0.25mm. The cover plate 210 is made of zirconium corundum refractory material and is bonded and fixed to the second ventilation module 209 with refractory putty. There are 12-20 slits 214, which are evenly distributed radially. The inner wall of the slits 214 is free of burrs and cracks, which can effectively prevent molten steel from seeping in, while ensuring that the gas is discharged in the form of small bubbles with a bubble diameter controlled between 1mm and 3mm, thereby improving the stirring effect of the molten steel.

[0027] In this embodiment, the axial height of the first ventilator 201 is greater than the axial height of the second ventilator 209. The ratio of the height of the first ventilator 201 to the height of the second ventilator 209 is 2:1 to 5:1, and the axial ratio of the first ventilator 201 to the second ventilator 209 is preferably 3:1. This height ratio ensures that the first ventilator 201 has sufficient structural strength and heat dissipation space, prevents the heat of the second ventilator 209, which is close to the molten steel, from being quickly conducted to the air inlet port 204, and shortens the ventilation path of the second ventilator 209, reducing gas flow resistance and improving blowing efficiency.

[0028] In this embodiment, a refractory filling layer 5 is provided between the outer wall of the permeable brick component 2 and the inner wall of the installation channel 4. The thickness of the refractory filling layer 5 is 5mm to 15mm. The end of the installation channel 4 near the inside of the ladle is inclined relative to the horizontal plane, with an inclination angle of 10° to 20°. The refractory filling layer 5 is made of monolithic high-alumina refractory castable. After filling, it is dried at 110°C and fired at 800°C to ensure that the filling is dense, without pores or cracks, and plays a role in sealing, heat preservation and buffering. The inclined direction of the installation channel 4 is towards the center of the ladle, which can make the discharged gas gather towards the center of the ladle, improve the uniformity of steel molten mixing, and at the same time reduce the scouring of the top of the permeable brick component 2 by the steel molten steel, thus extending its service life.

[0029] In this embodiment, an annular protective layer is provided between the working end face of the second venting module 209 and the upper end face of the seat brick 1. The annular protective layer is made of a refractory material with better thermal shock resistance than the second venting module 209, and is made of magnesium aluminum spinel refractory material. The annular protective layer is ring-shaped, with its inner diameter matching the outer diameter of the second venting module 209 and its outer diameter matching the upper inner diameter of the mounting channel 4 of the seat brick 1. It is fixed between the working end face of the second venting module 209 and the upper end face of the seat brick 1 by refractory mortar, which can effectively prevent molten steel from scouring and eroding the connection, reduce thermal stress damage, and extend the overall service life of the venting device.

[0030] Another aspect of the present invention provides a ladle, including a ladle body and a bottom-blowing ventilation device as described above, installed at the bottom of the ladle body.

[0031] The working principle and workflow of this device are as follows: S1: Fix the seat brick 1 to the bottom of the ladle body 3, ensuring that at least two sets of installation channels 4 inside the seat brick 1 are accurately positioned, and that the end of the installation channel 4 closest to the inside of the ladle is tilted at 10°~20° to provide a reasonable angle for gas injection and enhance the stirring effect of molten steel; fill the space between the outer wall of the permeable brick component 2 and the inner wall of the installation channel 4 with a refractory filling layer 5 of 5mm~15mm thickness to achieve sealing and fixation, and prevent high-temperature molten steel leakage or gas leakage; ensure that the annular protective layer between the working end face of the second permeable module 209 and the upper end face of the seat brick 1 is installed in place to resist the high temperature and thermal shock of molten steel; connect one end of the high-pressure gas pipe 205 to the external inert gas supply system, and the other end to the first permeable module 201 through the air inlet pipe interface 204; check that the flow control valve 206 is in normal condition and can flexibly adjust the gas flow rate; S2: The external gas supply system is activated. Inert gas is delivered to the air inlet port 204 at the bottom of the first ventilator 201 through the high-pressure gas pipe 205, and enters the gas collection chamber 202 inside the first ventilator 201. The gas collection chamber 202 achieves preliminary gas convergence and pressure stabilization. The gas in the gas collection chamber 202 is evenly distributed to at least eight sets of first ventilation channels 203 extending axially. The gas flows upward along the first ventilation channels 203 to complete the preliminary distribution and ensure uniform gas distribution. Since the axial height of the first ventilator 201 is 2 to 5 times that of the second ventilator 209, the longer ventilation channels can further stabilize the airflow and avoid pressure fluctuations. S3: The gas flowing out through the first ventilation channel 203 enters the air chamber layer 207 between the first ventilation module 201 and the second ventilation module 209. The air chamber layer 207 is enclosed by refractory material to form a gas buffer space, which plays a role in buffering and stabilizing the airflow, and avoids the gas directly impacting the second ventilation module 209 and causing airflow turbulence. At least six sets of spiral guide vanes 208 arranged circumferentially in the air chamber layer 207 apply a guiding effect to the gas, so that the gas flowing through the buffer space generates a circumferential rotation component and forms a rotating airflow. S4: The rotating airflow enters the module through the air inlet 211 on the bottom surface of the second ventilation module 209 and flows upward along at least eight sets of radially spirally arranged second ventilation channels 212. The radially spirally arranged channels further enhance the rotational characteristics of the gas and simultaneously achieve secondary diversion of the gas, making the gas distribution more uniform. The gas flowing out through the second ventilation channel 212 converges to the exhaust chamber 213 at the top of the second ventilation module 209. The exhaust chamber 213 performs final pressure stabilization and convergence on the rotating airflow to ensure that the gas pressure ejected from all slits 214 is consistent. S5: The inert gas in the exhaust chamber 213 is injected at high speed into the molten steel in the ladle through several radial slits 214 on the top working end face of the cover plate 210. The rotating airflow ejected drives the molten steel to generate tangential motion, which is superimposed with the lateral flow generated by the inclined installation of the ventilation device to form a composite spiral flow field, thereby significantly improving the stirring efficiency and the floating rate of inclusions. During the process, the gas flow rate can be adjusted by the flow control valve 206 to adapt to the stirring requirements of different refining stages and ensure the refining effect and the quality of molten steel.

[0032] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A ventilation device for bottom air blowing in a steel ladle, characterized in that: The device includes a base brick (1), which has at least two sets of installation channels (4) through it. Each of the two sets of installation channels (4) is equipped with a permeable brick assembly (2). The base brick (1) is used to install on the bottom of the ladle. The permeable brick assembly (2) includes at least two first permeable modules (201) and second permeable modules (209) stacked along the axial direction. The first permeable module (201) is located below the second permeable module (209). An air chamber layer (207) is provided between the first permeable module (201) and the second permeable module (209). The air chamber layer (207) is enclosed by refractory material and forms a gas buffer space inside that connects the first permeable module (201) and the second permeable module (209).

2. The ventilating device for bottom air blowing in a steel ladle according to claim 1, characterized in that: The first ventilated module (201) is located at the end away from the inner wall of the ladle, and the second ventilated module (209) is located at the end close to the inside of the ladle. The first ventilated module (201) and the second ventilated module (209) are interconnected through the gas buffer space of the air chamber layer (207).

3. The air-permeable device for bottom air blowing in a steel ladle according to claim 2, characterized in that: The first ventilation module (201) has an air collection chamber (202) at the bottom. The first ventilation module (201) has at least eight sets of first ventilation channels (203) extending axially. The lower end of the first ventilation channel (203) is connected to the air collection chamber (202). An air inlet interface (204) is fixedly connected to the middle of the bottom surface of the first ventilation module (201). A high-pressure air pipe (205) for connecting to an external air supply system is fixedly connected to the end of the air inlet interface (204) away from the first ventilation module (201). A flow control valve (206) is installed on the high-pressure air pipe (205).

4. The air-permeable device for bottom air blowing in a steel ladle according to claim 2, characterized in that: The gas chamber layer (207) is provided with at least six sets of guide vanes (208) arranged circumferentially. The guide vanes (208) are spirally distributed to generate a circumferential rotation component in the gas flowing through the gas buffer space.

5. The air-permeable device for bottom air blowing in a steel ladle according to claim 2, characterized in that: The second ventilation module (209) has an air inlet (211) on its bottom surface, and at least eight sets of second ventilation channels (212) are provided inside the second ventilation module (209). The second ventilation module (209) has an exhaust chamber (213) on its top surface. The second ventilation channels (212) are used to connect the upper exhaust chamber (213) and the lower air inlet (211), and the at least eight sets of second ventilation channels (212) are arranged in a radial spiral.

6. The ventilating device for bottom air blowing in a steel ladle according to claim 5, characterized in that: A cover plate (210) is fixedly connected above the second ventilation module (209). The top working end face of the cover plate (210) is provided with a number of slits (214) distributed radially. The slits (214) are connected to the exhaust chamber (213). The width of the slits (214) is 0.08 mm to 0.25 mm.

7. The air-permeable device for bottom air blowing in a steel ladle according to claim 2, characterized in that: The height of the first breathable module (201) along the axial direction is greater than the height of the second breathable module (209) along the axial direction, and the ratio of the height of the first breathable module (201) to the height of the second breathable module (209) is 2:1 to 5:

1.

8. The venting device for bottom air blowing in a steel ladle according to claim 1, characterized in that: A refractory filling layer (5) is provided between the outer wall of the permeable brick assembly (2) and the inner wall of the installation channel (4). The thickness of the refractory filling layer (5) is 5 mm to 15 mm. The end of the installation channel (4) near the inside of the ladle is inclined relative to the horizontal plane, and its inclination angle is 10° to 20°.

9. The ventilating device for bottom air blowing in a steel ladle according to claim 7, characterized in that: An annular protective layer is provided between the working end face of the second ventilated module (209) and the upper end face of the seat brick (1). The annular protective layer is made of a refractory material with better thermal shock resistance than the second ventilated module (209).

10. A steel ladle, comprising a ladle body (3), characterized in that, It also includes a bottom-blowing air-permeable device for the ladle as described in any one of claims 1 to 9, which is installed at the bottom of the ladle body (3).

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