Tundish nozzle self-heating device

Abstract

The present application relates to the field of metallurgical continuous casting, in particular to a tundish nozzle self-heating device. The fairing of the heating device comprises a bottom sheet located below the nozzle and multiple fairing vanes hinged on the periphery of the bottom sheet, and a high-temperature-resistant elastic fiber cloth is connected between any two adjacent fairing vanes for sealing. The periphery of the bottom sheet locally extends with a mounting strip installed and fixed inside the baking cover. The inner side wall of the baking cover is correspondingly provided with multiple drive motors corresponding to the multiple fairing vanes. The inner side wall of each fairing vane extends with a limiting piece towards the outer side wall of the nozzle. The multiple fairing vanes can be driven by the multiple drive motors to rotate around the periphery of the bottom sheet and approach the outer side wall of the nozzle until the multiple limiting pieces are stopped by the outer side wall of the nozzle, which can adapt to nozzles of different sizes and has wide versatility.

Description

Technical Field

[0001] This invention relates to the field of metallurgical continuous casting, and more particularly to a self-heating device for the tundish nozzle. Background Technology

[0002] The tundish is a refractory container used in the continuous casting process of steelmaking. Its top is open and aligned with the ladle above it. The ladle contains molten steel, and the bottom of the tundish has multiple nozzles, each with a crystallizer placed below it. During casting, the tundish receives the molten steel poured from the ladle, and the multiple nozzles at its bottom distribute the molten steel into multiple crystallizers for solidification to form a cast billet.

[0003] To ensure smooth continuous casting, the tundish cavity and tundish nozzle need to be baked before casting. In existing technology, a gas nozzle is used to inject flames into the tundish cavity to bake it. For nozzle baking, a negative pressure nozzle baking device is mainly used. This device includes a detachable baking hood installed at the bottom of the tundish, which covers the nozzle. Inside, a guide shroud covers the lower part of the nozzle (there is a gap between the nozzle and the guide shroud). A bent exhaust pipe connects to the bottom of the baking hood, and a compressed gas pipe is installed at the bend of the exhaust pipe. Compressed gas is continuously injected at high speed into the exhaust pipe, pushing the gas out of the exhaust pipe and creating a negative pressure inside the baking hood. Heat from the bottom of the tundish continuously flows out of the nozzle and into the guide shroud to bake the inner wall of the nozzle, and then flows out from the top of the guide shroud to bake the outer wall of the nozzle. This nozzle baking device has a fixed guide shroud size and can only be used for nozzles of a single size. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a self-heating device for the tundish nozzle, which can adapt to nozzles of different sizes and has wide versatility.

[0005] To solve the above problems, the present invention provides a self-heating device for tundish nozzles, comprising a baking hood detachably installed at the bottom of the tundish, the baking hood covering the nozzle, and a guide hood inside the tundish covering the lower part of the nozzle, with a gap between the nozzle and the inner wall of the guide hood. A negative pressure device is connected below the baking hood, and the negative pressure device operates to carry out the gas inside the baking hood, creating a negative pressure inside the baking hood, thereby absorbing the heat from the bottom of the tundish into the baking hood to heat the nozzle. The guide hood includes a base plate located below the nozzle and multiple guide blades hinged to the periphery of the base plate. A mounting strip extends from the periphery of the base plate and is fixed inside the baking hood. Multiple drive motors are correspondingly provided on the inner wall of the baking hood, one for each of the multiple guide blades. Each guide blade has a limiting member extending from its inner wall toward the outer wall of the nozzle. The multiple drive motors can drive the multiple guide blades to rotate forward relative to the base plate toward the outer wall of the nozzle until the multiple limiting members are blocked by the outer wall of the nozzle. A high-temperature resistant elastic fiber cloth is connected between any two adjacent guide blades for sealing.

[0006] Furthermore, the substrate is square, with four guide vanes and four corresponding drive motors; the bottoms of the four guide vanes are respectively hinged to the four sides of the top surface of the substrate by four torsion springs, and under the action of the torsion springs, they rotate in opposite directions relative to the substrate and move away from each other.

[0007] Furthermore, the drive motor is specifically a telescopic motor. The output ends of the four telescopic motors extend synchronously and push the four guide vanes respectively, so that the four guide vanes overcome the torsion spring force and rotate in the positive direction relative to the bottom plate to move closer to each other to adapt to the size of the sprue.

[0008] Furthermore, a tube is fixedly inserted through the film, with the lower end of the tube extending out to the outside of the baking hood and connecting to the gas source. The upper part of the tube is vertically placed in the inner cavity of the water inlet, with the upper end closed. A flame head is provided on the side wall of the upper part of the tube. The flame head ignites the gas and sprays out a flame to heat the inner cavity of the water inlet, causing the water inlet to dehydrate quickly.

[0009] Furthermore, there are multiple flamethrowers, evenly arranged vertically and circumferentially.

[0010] Furthermore, a perforated circular mounting cover is detachably installed and fixed at the upper end of the insertion tube. The diameter of the mounting cover is larger than that of the water inlet, and the cover is placed horizontally on the upper end of the water inlet.

[0011] Beneficial effects: The flow guide includes a base plate located at the bottom of the sprue and multiple flow guide blades hinged around the periphery of the base plate. The multiple flow guide blades can be driven by multiple drive motors to rotate forward around the periphery of the base plate and approach the outer wall of the sprue. It can adapt to sprues of different sizes and has wide versatility. Attached Figure Description

[0012] Figure 1 This is a simplified structural diagram of the self-heating device at the tundish nozzle.

[0013] Figure 2 This is a simplified top view of the air deflector and the baking hood.

[0014] Figure 3 This is a simplified structural diagram of the self-heating device at the tundish nozzle, showing the direction of gas flow.

[0015] Figure 4 This is a simplified structural diagram of the second embodiment of the self-heating device for the intermediate ladle nozzle.

[0016] Symbol explanation: 1-Intermediate liner; 2-Water inlet; 3-Mounting boss; 4-Insertion pipe; 5-Baking hood; 6-Valve; 7-Guide hood; 8-Telescopic motor; 9-Exhaust pipe; 10-Compressed gas pipe; 41-Mounting cover; 42-Flame head; 71-Guide hood base plate; 72-Guide hood guide vanes; 73-Fiber cloth; 74-Limiting component; 75-Torsion spring; 76-Mounting strip; 81-Telescopic motor output end. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to specific embodiments.

[0018] First implementation example Figure 1 As shown, the bottom of the tundish 1 has an annular mounting boss 3 around the outer periphery of the nozzle 2. The self-heating device for the tundish nozzle includes a baking cover 5 covering the bottom of the tundish 1, and the top of the baking cover 5 is detachably fixed to the mounting boss 3 by means of screws. A sealing gasket (not shown in the attached figure) is sandwiched between the baking cover 5 and the mounting boss 3.

[0019] Inside the baking hood 5, a guide shield 7 is provided below the sprue 2 to cover the lower part of the sprue 2. The guide shield 7 includes a square base plate 71 located below the sprue 2 and four guide vanes 72 spaced apart around the sprue 2. Neither the guide vanes 72 nor the base plate 71 contacts the sprue 2; that is, a gap is left between the guide shield 7 and the sprue 2. A mounting strip 76 extends from each of the four sides of the base plate 71 (see...). Figure 2 The four guide vanes 72 are mounted and fixed on the inner wall of the baking hood 5. The bottoms of the four guide vanes 72 are hinged to the four sides of the top surface of the base plate 71 via four torsion springs 75. Under the action of the torsion springs 75, they rotate in opposite directions relative to the base plate 71, moving away from each other. Four telescopic motors 8 are correspondingly provided on the inner wall of the baking hood 5, one for each of the four guide vanes 72. The output ends 81 of the four telescopic motors 8 extend synchronously, pushing the four guide vanes 72 to overcome the elastic force of the torsion springs 75 and rotate forward relative to the base plate 71, bringing them closer together to adapt to the size of the sprue 2. Each guide vane 72 has a limiting member 74 extending from its inner wall towards the outer wall of the sprue 2. The four guide vanes 72 can be driven by the four telescopic motors 8 to move closer together until the four limiting members 74 are pressed against the outer wall of the sprue 2. See [link / description]. Figure 2Any two adjacent guide vanes 72 are sealed by a high-temperature resistant elastic fiber cloth 73 (such as zirconium aluminosilicate ceramic fiber cloth).

[0020] The bottom of the baking hood 5 is connected to a bent exhaust pipe 9. A compressed gas pipe 10 is connected to the bend in the exhaust pipe 9. The inlet of the compressed gas pipe 10 is connected to an external compressed air source (not shown in the attached diagram). The exhaust port of the compressed gas pipe 10 extends into the exhaust pipe 9 along the exhaust direction. In the actual continuous casting process, before casting begins, both the tundish 1 and the nozzle 2 need to be heated from room temperature to approximately 1100°C. The heating from room temperature to 800°C is primarily for dehydration of the tundish 1 and nozzle 2. After the tundish 1 is heated from room temperature to 800°C, the operator opens the valve 6 on the compressed gas pipe 10. Compressed air from the external compressed air source is continuously and at high speed injected into the exhaust pipe 9 from the compressed gas pipe 10, pushing the gas in the exhaust pipe 9 and the baking hood 5 out along the exhaust direction of the exhaust pipe 9, thus creating a negative pressure inside the baking hood 5. The hot gas at the bottom of the tundish cavity 1 will then continuously press... Figure 3 The air flows in the direction of the arrow shown. First, it is drawn from the sprue 2 into the guide shroud 7 to heat the inner wall of the sprue 2. Then, it is drawn from the top of the guide shroud 7 into the baking shroud 5 to heat the outer wall of the sprue 2. After the side wall of the sprue 2 is heated to 1100°C, the valve 6 on the compressed gas pipe 10 is closed to end the heating of the sprue 2. In this embodiment, the exhaust pipe 9, the compressed gas pipe 10, and the external compressed air source together form a negative pressure device, which continuously draws the hot gas in the intermediate package 1 into the baking shroud 5 to heat the sprue 2, eliminating the need to use a flame to heat the sprue 2.

[0021] In actual use, the hot gas supplied from the inner cavity of the tundish 1 is used to heat the nozzle 2. The heating rate is slow, affecting the continuous casting process. Furthermore, if the heating time is insufficient, the sidewalls of nozzle 2 may not be fully dehydrated, making it prone to cracking during casting. Therefore, this application provides a second embodiment, which is described in [link to second embodiment]. Figure 4 It is largely the same as the first embodiment, with the following differences: A bent insert 4 is fixedly threaded through the substrate 71, with its lower end extending out to the outside of the baking hood 5 and connecting to a gas source (not shown in the attached diagram). The upper part of the insert 4 is vertically positioned inside the cavity of the water inlet 2, with its upper end closed. Multiple burner heads 42 are evenly arranged vertically and circumferentially on the upper side wall of the insert 4 (the specific structure and usage position of the insert 4 and burner heads 42 can be found in patent document CN219335963U). The multiple burner heads 42 ignite the gas in the insert 4, ejecting flames to heat the side wall of the water inlet 2. In this embodiment, the diameter of the inner cavity of the water inlet 2 is 80~160mm, and the inner cavity of the water inlet 2 is spacious, allowing for smooth gas flow.

[0022] In the actual continuous casting process, because the tundish 2 has a larger volume, its temperature rises more slowly than that of the nozzle 2. Therefore, the inner cavity of the tundish 1 is heated first. After the tundish 1 is heated to 800°C, the burner head 42 is turned on to heat the side wall of the nozzle 12 to 800°C, allowing the side wall of the nozzle 2 to quickly dehydrate. Then, the burner head 42 is turned off, and the valve 6 is opened to draw out the hot gas inside the tundish 1 to heat the nozzle 2 until the side wall temperature of the nozzle reaches 1100°C. This heating method ensures that the nozzle 2 reaches the required temperature and is fully dehydrated before casting begins.

[0023] The insert 4 is equipped with a hollowed-out circular mounting cover 41, the diameter of which is larger than that of the inlet 2. The upper end of the insert 4 has threads on its outer circumference, and the bottom of the circular mounting cover 41 has a corresponding threaded hole. Before baking the tundish 1, the operator places the mounting cover 41 flat above the inlet 2, aligns the threaded hole at the bottom of the mounting cover 41 with the insert 4, and fits it onto the upper end of the insert 4. The operator then rotates the mounting cover 41 to fix it in place until the bottom of the mounting cover 41 covers the upper end of the inlet 2, thus securing the entire heating device more firmly to the bottom of the tundish 1.

[0024] The above description is merely an embodiment of the present invention and does not limit the scope of patent protection. Any non-substantial changes or substitutions made by those skilled in the art based on the present invention will still fall within the scope of patent protection.

Claims

1. A self-heating device for tundish nozzles, comprising a baking hood (5) detachably installed at the bottom of a tundish (1), the baking hood (5) covering the nozzle (2), and a guide hood (7) provided below the nozzle (2) covering the lower part of the nozzle (2), with a gap between the nozzle (2) and the inner wall of the guide hood (7), and a negative pressure device connected below the baking hood (5), the negative pressure device working to carry out the gas inside the baking hood (5) to form a negative pressure inside the baking hood (5), thereby drawing heat from the bottom of the tundish (1) into the baking hood (5) to heat the nozzle (2), characterized in that: The guide shield (7) includes a base plate (71) located below the water inlet (2) and multiple guide blades (72) hinged around the base plate (71). A mounting strip (76) extends out from the side of the base plate (71) and is fixed inside the baking hood (5). Multiple drive motors are provided on the inner wall of the baking hood (5) corresponding to the multiple guide blades (72). The inner wall of each guide blade (72) extends a limiting piece (74) towards the outer wall of the water inlet (2). The multiple drive motors can drive the multiple guide blades (72) to rotate in the forward direction relative to the base plate (71) and approach the outer wall of the water inlet (2) until the multiple limiting pieces (74) are blocked by the outer wall of the water inlet (2). A high-temperature resistant elastic fiber cloth (73) is connected between any two adjacent guide blades (72) for sealing.

2. The self-heating device for the tundish nozzle as described in claim 1, characterized in that: The substrate (71) is square, and there are four guide vanes (72), and four drive motors are correspondingly provided. The bottom of the four guide vanes (72) are respectively hinged to the four sides of the top surface of the substrate (71) by four torsion springs (75). Under the action of the torsion springs (75), they rotate in opposite directions relative to the substrate (71) and move away from each other.

3. The self-heating device for the tundish nozzle as described in claim 2, characterized in that: The drive motor is specifically a telescopic motor (8). The output ends (81) of the four telescopic motors (8) extend synchronously and push the four guide vanes (72) respectively, so that the four guide vanes (72) overcome the elastic force of the torsion spring (75) and rotate in the positive direction relative to the bottom plate (71) to move closer to each other to adapt to the size of the sprue (2).

4. The self-heating device for the tundish nozzle as described in claim 1, characterized in that: A tube (4) is fixedly installed on the substrate (71). The lower end of the tube (4) extends out to the outside of the baking hood (5) and connects to the gas source. The upper part of the tube (4) is vertically placed in the inner cavity of the water outlet (2) and the upper end is closed. A flame head (42) is provided on the side wall of the upper part of the tube (4). The flame head (42) ignites the gas in the tube (4) and sprays out a flame to heat the inner cavity of the water outlet (2) so that the water outlet (2) is quickly dehydrated.

5. The self-heating device for the tundish nozzle as described in claim 4, characterized in that: There are multiple flamethrowers (42), which are evenly arranged vertically and circumferentially.

6. The self-heating device for the tundish nozzle as described in claim 1, characterized in that: The upper end of the insertion tube (4) is detachably fitted with a hollow circular mounting cover (41). The diameter of the mounting cover (41) is larger than that of the water inlet (2), and the cover is placed flat on the upper end of the water inlet (2).

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