Large-section hot top crystallizer for continuous casting

Abstract

The large-section hot top crystallizer for continuous casting is arranged between a continuous casting machine tundish (2) and a conventional outer crystallizer (10), and the hot top crystallizer is provided with the following circular ring-shaped components which are coaxially arranged: a hot top crystallizer metal shell (4), an induction heating coil (7), an outer fire-resistant working layer (8) and an inner fire-resistant working layer (9); the outer fire-resistant working layer and the inner fire-resistant working layer form an annular cavity which is used for accommodating molten steel which is introduced into the tundish through the submersed nozzle; an induction heating coil and a hot top crystallizer metal shell are sequentially arranged on the outer side of the outer fire-resistant working layer, and a plurality of inclined flow guide holes (15) are formed in the inner fire-resistant working layer and used for distributing and guiding molten steel flowing into the hot top crystallizer between the outer fire-resistant working layer and the inner fire-resistant working layer. According to the hot top crystallizer, a plurality of flow guide hole structures arranged on the inner refractory working layer have the functions of shunting and uniformizing a temperature field, and meanwhile, the impact depth of molten steel in the crystallizer can be reduced.

Description

Technical Field

[0001] The utility model belongs to the field of metal continuous casting, in particular to a crystallizer auxiliary device for producing large-section pipe blanks or large-section steel blanks by continuous casting. Background Art

[0002] For a long time, the production of large-section pipe billets and large-section ingots by continuous casting has been a development direction of continuous casting. To this end, technicians in this field have been making unremitting efforts in the technical direction of directly using continuous casting methods to produce large-section steel billets.

[0003] The production of large-section ingots usually adopts multi-nozzle or multi-hole single-nozzle casting, which will form uneven flow field inside the crystallizer, affecting the uniformity of heat transfer and shell formation. When casting ingots with thin wall thickness, large or small sections, the shape of the crystallizer and the nozzle needs to be changed to meet the requirements. For example, Chinese invention patent CN1084439A discloses a "ultra-small section billet continuous casting device", which only solves the problem of small section casting nozzle insertion, and cannot be applied to large section thin wall billets and large section billets; Chinese invention patent CN106424612A discloses a "tube crystallizer and continuous casting and rolling tube production line", the tube crystallizer contains an external component and an internal component, the external component contains an open hot top 305 and a lower cylinder connected correspondingly up and down, the open hot top 305 is funnel-shaped, a graphite ring is provided at the connection between the open hot top and the lower cylinder, the graphite ring is located on the inner surface of the external component, a metal shielding cover is provided outside the open hot top, and an induction coil is provided outside the external component. This technical solution directly and closely connects continuous casting and rolling, and cannot meet the production needs of changing the size and shape of the crystallizer and nozzle when producing billets with different wall thicknesses. Summary of the invention

[0004] The purpose of the utility model is to provide a hot top crystallizer for large-section continuous casting, which is arranged above the conventional outer crystallizer 10 and below the tundish 2 during production, and can better adapt to the production of large-section pipe blanks with thin wall thicknesses, and can also be used for casting the production of steel billets with larger sections.

[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0006] A hot top crystallizer for large-section continuous casting, arranged between a tundish 2 of a continuous casting machine and a conventional outer crystallizer 10, the hot top crystallizer having the following coaxially arranged annular components: a hot top crystallizer metal shell 4, an induction heating coil 7, an outer refractory working layer 8 and an inner refractory working layer 9;

[0007] The outer refractory working layer 8 and the inner refractory working layer 9 form an annular cavity for accommodating the molten steel 1 in the tundish introduced through the submerged water nozzle 3; the induction heating coil 7 and the hot top crystallizer metal shell 4 are sequentially arranged on the outside of the outer refractory working layer 8, and a plurality of oblique guide holes 15 are opened inside the inner refractory working layer 9 for diverting and guiding the molten steel 14 in the hot top crystallizer flowing into the outer refractory working layer 8 and the inner refractory working layer 9.

[0008] The guide hole 15 of the inner refractory working layer 9 is in the shape of a straight line segment, and the direction of the straight line segment is one of the following directions or a combination thereof:

[0009] I. The projection of the straight line segment of the guide hole 15 on the horizontal plane is tangent to the projection of the inner wall of the inner refractory working layer 9;

[0010] II. The straight section of the guide hole 15 is located in a plane perpendicular to the horizontal plane and has an angle of 0 to 45° downward with the horizontal plane.

[0011] The hot top crystallizer is detachably connected to a conventional outer crystallizer 10 via pins 6 and wedges 5 on a metal shell 4 of the crystallizer.

[0012] When the guide holes 15 are in direction I, the multiple guide holes are evenly distributed along the circumference, and the number is 6 to 12.

[0013] When the guide hole 15 is in direction II, there is an angle of 45° downwards between the straight line segment and the horizontal plane.

[0014] The beneficial technical effects of the utility model are:

[0015] The hot top crystallizer of the utility model is to move the water inlet to the outer part of the hot top crystallizer and between the inner refractory materials when producing large-section tube billets or large-section steel billets, and then introduce the molten steel into the conventional outer crystallizer through the openings on the inner refractory materials. This solution can simultaneously solve the practical problems of thin tube billet wall thickness, limited water inlet insertion and impact depth of molten steel, and can also be used to solve the problem of uneven temperature field when casting large-section steel billets.

[0016] The induction heating coil of the hot top crystallizer can supplement the heat of the molten steel in the hot top crystallizer; the multiple guide hole structures arranged in the inner refractory working layer have the functions of diversion and uniform temperature field; at the same time, the impact depth of the molten steel in the crystallizer can be reduced.

[0017] This hot top crystallizer can meet the production of different thin-walled, large-section billets and large-section ingots.

[0018] The hot top crystallizer has a simple structure, is easy to maintain, and is convenient to manufacture and implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1It is a schematic diagram of the assembly of a hot top crystallizer for large-section continuous casting of the utility model, a tundish 2 and a conventional outer crystallizer 10;

[0020] Figure 2 This is a schematic diagram of the assembly of the hot top crystallizer of the utility model when it is used for the production of large-section tube blanks;

[0021] Figure 3-1 , Figure 3-2 This is a schematic diagram of the oblique guide holes of the inner refractory working layer of the utility model in the horizontal plane, wherein: Figure 3-1 This is the main view of the inner refractory working layer. Figure 3-2 for Figure 3-1 A top view of

[0022] Figure 4-1 , Figure 4-2 This is a schematic diagram of the oblique guide holes of the inner refractory working layer of the utility model in the height direction, wherein: Figure 4-1 This is the main view of the inner refractory working layer. Figure 4-2 for Figure 4-1 Left view of .

[0023] Reference numerals:

[0024] 1 Molten steel in tundish 2 Tundish

[0025] 3 Immersed water nozzle 4 Hot top crystallizer metal shell

[0026] 5 wedges 6 pins

[0027] 7 Induction heating coil 8 External refractory working layer

[0028] 9Inner refractory working layer 10Conventional outer crystallizer

[0029] 11 inner shell of crystallizer 12 inner crystallizer

[0030] 13 Molten steel in the crystallizer 14 Molten steel in the hot top crystallizer

[0031] 15 diversion holes DETAILED DESCRIPTION

[0032] like Figure 1 As shown in Figure 4, a hot top crystallizer for large-section continuous casting is arranged between the continuous casting machine tundish 2 and the conventional external crystallizer 10. Specifically, the hot top crystallizer is arranged above the conventional external crystallizer 10 and below the tundish 2.

[0033] The hot top crystallizer comprises a hot top crystallizer metal shell 4, an induction heating coil 7, an outer refractory working layer 8 and an inner refractory working layer 9.

[0034] The outer refractory working layer 8 and the inner refractory working layer 9 form a cavity for accommodating the molten steel 1 in the tundish introduced through the submerged nozzle 3. The outer layer of the outer refractory working layer 8 is sequentially arranged with an induction heating coil 7 and a hot top crystallizer metal shell 4. The hot top crystallizer is connected to a conventional outer crystallizer 10 through a pin 6 and an inclined wedge 5 on the crystallizer metal shell 4.

[0035] The inner refractory working layer 9 is provided with a plurality of guide holes 15 in specific directions for diverting and guiding the molten steel 14 in the hot top crystallizer flowing between the outer refractory working layer 8 and the inner refractory working layer 9 .

[0036] The direction of the guide hole 15 can be along the horizontal direction (direction I) of FIG. 3 , or along the vertical direction (direction II) of FIG. 4 , or a combination of the two directions. In which: direction I means that the projection of the straight line segment of the guide hole 15 in the horizontal plane is tangent to the projection of the inner wall of the inner refractory working layer 9; direction II means that the straight line segment of the guide hole 15 is located in a plane perpendicular to the horizontal plane and has an angle of 0 to 45° downward with the horizontal plane.

[0037] During operation, the molten steel 1 in the tundish flows into the hot top crystallizer through the submerged water nozzle 3. The cavity formed by the outer refractory working layer 8 and the inner refractory working layer 9 of the hot top crystallizer buffers the molten steel, and then flows into the conventional outer crystallizer 10 through the guide holes 15 arranged in the above direction in the inner refractory working layer 9, thereby slowing down the impact depth of the molten steel 13 in the crystallizer and making the temperature field of the molten steel 13 in the crystallizer more uniform. The hot top crystallizer can also be used to configure the inner crystallizer 12 inside the conventional outer crystallizer 10 for the working scene of producing tube blanks.

[0038] The induction heating coil 7 can supplementally heat the molten steel 14 in the hot top crystallizer to prevent the molten steel 14 in the hot top crystallizer from solidifying before flowing into the conventional outer crystallizer 10 through the guide hole 15 during the production of large-section steel billets.

[0039] The guide holes 15 on the inner refractory working layer 9 can adjust the direction in which the molten steel 14 in the hot top crystallizer flows into the conventional outer crystallizer 10.

[0040] The guide holes 15 can reduce the impact of the molten steel 13 in the conventional outer crystallizer on the inner shell 11 of the crystallizer.

[0041] The hot top crystallizer can be used for casting thin-walled large-section tube billets, and can also be used for casting large-section steel billets.

Claims

1. A hot top crystallizer for large cross-section continuous casting, arranged between a tundish (2) of a continuous casting machine and a conventional external crystallizer (10), characterized in that: The hot top crystallizer comprises the following coaxially arranged annular parts: a hot top crystallizer metal shell (4), an induction heating coil (7), an outer refractory working layer (8) and an inner refractory working layer (9); The outer refractory working layer (8) and the inner refractory working layer (9) form an annular cavity for accommodating the molten steel (1) in the tundish introduced through the submerged water nozzle (3); the induction heating coil (7) and the hot top crystallizer metal shell (4) are sequentially arranged outside the outer refractory working layer (8), and the inner refractory working layer (9) is provided with a plurality of oblique guide holes (15) for diverting and guiding the molten steel (14) in the hot top crystallizer flowing into the outer refractory working layer (8) and the inner refractory working layer (9).

2. The hot top crystallizer according to claim 1, characterized in that: The flow guide hole (15) of the inner refractory working layer (9) is in the shape of a straight line segment, and the direction of the straight line segment is one of the following directions or a combination thereof: I. The projection of the straight line segment of the guide hole (15) on the horizontal plane is tangent to the projection of the inner wall of the inner refractory working layer (9); II. The straight section of the guide hole (15) is located in a plane perpendicular to the horizontal plane and has an angle of 0 to 45° downward with the horizontal plane.

3. The hot top crystallizer according to claim 1, characterized in that: The hot top crystallizer is detachably connected to a conventional outer crystallizer (10) via pins (6) and inclined wedges (5) on a metal shell (4) of the crystallizer.

4. The hot top crystallizer according to claim 2, characterized in that: When the guide holes (15) are in direction I, the plurality of guide holes are evenly distributed along the circumference, and the number of the guide holes is 6 to 12.

5. The hot top crystallizer according to claim 2, characterized in that: When the guide hole (15) is in direction II, there is an angle of 45° downwards between the straight line segment and the horizontal plane.

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