A submerged nozzle

Abstract

The present application belongs to the technical field of continuous casting refractory, and particularly relates to a submerged nozzle, which comprises a nozzle body, wherein the nozzle body comprises a bowl mouth portion, a constant diameter portion, a first diameter changing portion and a second diameter changing portion connected in sequence from top to bottom, a flow guide separation block is arranged in the second diameter changing portion, an inner wall of the constant diameter portion defines an inlet hole, the inlet hole extends to the bottom of the first diameter changing portion and is connected with the flow guide separation block, the flow guide separation block abuts against the bottom of the inlet hole on the inner side of the first diameter changing portion, a flow stabilizing structure is arranged on the flow guide separation block, and the outlet of the inlet hole is in the shape of an inverted trapezoid. The nozzle is improved on the basis of the existing one by adding the flow stabilizing structure, can effectively reduce the liquid level fluctuation of a crystallizer and can fully play the effect of continuous casting.

Description

Technical Field

[0001] This invention belongs to the technical field of refractory materials for continuous casting, and specifically relates to an immersion nozzle. Background Technology

[0002] Continuous casting of steel is a process in which superheated molten steel is continuously cooled into a solid billet of a specific shape using a water-cooled crystallizer. With the application and development of continuous casting technology, especially due to increasingly higher requirements for steel quality from users and fierce competition in the international market, the quality of continuously cast billets is receiving more and more attention. Strictly controlling the cleanliness of molten steel and reducing billet defects has become an important task in continuous casting production.

[0003] The crystallizer, as the "heart" of the continuous casting machine, is the origin of most surface defects and internal quality problems in continuously cast billets. Statistics show that nearly 80% of surface defects in billets originate in the crystallizer. It is also the final link in controlling the quality of molten steel in the continuous casting process, determining the surface quality of the billet and the content and distribution of non-metallic inclusions. The flow state of the molten steel within the crystallizer directly affects the quality of the billet and the content and distribution of non-metallic inclusions. Currently, the main methods to improve the flow of molten steel within the crystallizer are electromagnetic stirring and electromagnetic braking technologies. However, because the crystallizer is made of a water-filled copper plate, the magnetic field is shielded by the copper plate, resulting in significant attenuation and severely affecting the effectiveness and efficiency of the electromagnetic field.

[0004] A submerged entry nozzle (SAN) is a refractory sleeve installed at the bottom of the tundish and inserted below the molten steel surface in a continuous casting machine. During continuous casting, the refined molten steel, after being treated in the tundish, is continuously injected into the crystallizer through the SAN for cooling and solidification. While protecting the steel flow and preventing secondary oxidation, the SAN also alters the flow state of the molten steel within the crystallizer, significantly impacting the quality and output of the continuously cast billets. Uneven flow of molten steel within the SAN causes uneven discharge from each outlet, resulting in fluctuations in the molten steel surface within the crystallizer. This can easily lead to slag entrapment defects, and the severity of these fluctuations increases with casting speed, limiting the implementation of high-speed continuous casting and hindering the achievement of greater economic benefits. Another very important point is that the upper corner of the discharge hole of the existing submerged entry nozzle can easily restrict the flow of molten steel and form a negative pressure area, causing the molten steel and protective slag to be sucked in and reflow into the crystallizer with the mainstream of molten steel. This increases the content of non-metallic inclusions in the molten steel and has a very adverse effect on the quality of the cast billet.

[0005] Basic research shows that the swirling flow of molten steel within a submerged entry nozzle in continuous casting can effectively improve the uniformity and stability of the nozzle outflow, improve the flow state and temperature distribution within the mold, and reduce surface fluctuations at the meniscus. However, while the swirling flow within the nozzle has a positive impact on the molten steel flow within the mold, it can also have adverse effects, such as increased impact on the mold's wide face. Existing submerged entry nozzles for continuous casting cannot suppress the adverse effects of the swirling flow within the nozzle on the molten steel flow within the mold, and therefore cannot fully meet the requirements of swirling flow continuous casting within the nozzle. Summary of the Invention

[0006] The purpose of this invention is to provide a submerged entry nozzle for continuous casting, which addresses the problems existing in the prior art. This nozzle is an improvement on the existing one, with the addition of a flow stabilizing structure, which can effectively reduce the fluctuation of the liquid level in the crystallizer and fully realize the effect of continuous casting.

[0007] The technical solution of this invention is:

[0008] An immersion-type water inlet includes an inlet body, which comprises a bowl-shaped portion, a portion of the same diameter, a first variable-diameter portion, and a second variable-diameter portion connected sequentially from top to bottom. A flow-guiding and separating block is disposed within the second variable-diameter portion. An inlet hole is defined by the inner wall of the portion of the same diameter. The inlet hole extends to the bottom of the first variable-diameter portion and connects with the flow-guiding and separating block. The upper part of the flow-guiding and separating block abuts against the bottom of the inlet hole on the inner side of the first variable-diameter portion. A flow-stabilizing structure is disposed on the flow-guiding and separating block. The outlet of the inlet hole is in the shape of an inverted trapezoid.

[0009] Specifically, the flow stabilizing structure is a flow stabilizing hole, which horizontally penetrates the flow guiding and separating block.

[0010] Specifically, the flow stabilizing hole is located in the lower middle part of the flow guiding and separating block.

[0011] Specifically, the diameter of the outlet at both ends of the flow stabilizing orifice is larger than the diameter of the middle orifice.

[0012] Specifically, the flow stabilizing structure includes a flow stabilizing vertical hole disposed in the center of the flow guiding and separating block, and a flow stabilizing branch hole connected to the flow stabilizing vertical hole, wherein the diameter of the flow stabilizing vertical hole is larger than the diameter of the flow stabilizing branch hole.

[0013] Specifically, there are at least four flow-stabilizing branch holes, which extend symmetrically in pairs to the lower side of the flow-guiding and separating block, and the outlet of the flow-stabilizing branch holes is located on the lower side of the flow-guiding and separating block.

[0014] Specifically, the flow stabilization structure is a spiral channel arranged from top to bottom inside the flow guiding and separating block. The spiral channel includes multiple layers of annular channels, with adjacent annular channels connected end to end.

[0015] Specifically, the spiral channel includes a spiral channel inlet and a spiral channel outlet. The spiral channel inlet is located at the middle of the upper part of the flow guide and separation block, corresponding to the inlet hole, and the spiral channel outlet is located at the middle of the lower part of the flow guide and separation block.

[0016] Specifically, the upper inlet of the flow guiding and separating block is arc-shaped with a radius of 15mm, and the diameter of the widest part of the flow guiding and separating block is 76mm.

[0017] The beneficial effects of this invention are as follows: This invention is an improvement on existing nozzles. By directly connecting the bottom of the inlet hole to the flow guide block, eliminating the gap between the inlet hole and the flow guide block, the impact of molten iron entering from the inlet hole on the flow guide block can be reduced. Furthermore, a flow stabilizing structure is installed on the flow guide block. Through the diversion and stabilization effect of the flow stabilizing structure, the molten iron on both sides of the flow guide block can be dispersed, balancing the water inflow at the outlets on both sides of the flow guide block. Therefore, it can further prevent liquid surface fluctuations caused by large water inflows. The improvements provided by this invention can uniformly distribute the outflow from the nozzle, reduce liquid surface fluctuations in the crystallizer, prevent the entrapment of protective slag, and fully utilize the continuous casting effect. Attached Figure Description

[0018] Figure 1 This is a schematic cross-sectional view of the submersible water inlet provided by the present invention.

[0019] Figure 2 This is a side cross-sectional view of the submersible water inlet provided by the present invention.

[0020] Figure 3 This is a schematic cross-sectional view of the submersible nozzle provided in Example 1;

[0021] Figure 4 This is a schematic cross-sectional view of the submersible nozzle provided in Example 2;

[0022] Figure 5 This is a schematic cross-sectional view of the immersion-type water inlet guide and separation block provided in Example 3.

[0023] 1. Same diameter section, 2. First variable diameter section, 3. Inlet orifice, 4. Second variable diameter section, 5. Flow guide and separation block.

[0024] 1. Same diameter section, 2. First variable diameter section, 3. Inlet orifice, 4. Second variable diameter section, 5. Flow guide and separation block.

[0025] 6. Flow stabilizing orifice, 7. Flow stabilizing branch orifice, 8. Flow stabilizing vertical orifice, 9. Spiral channel, 10. Spiral channel inlet.

[0026] 11. Spiral channel exit. Detailed Implementation

[0027] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] like Figure 1 and Figure 2 The diagram shows a cross-sectional view and a side cross-sectional view of an immersion-type water inlet provided by the present invention. The water inlet body includes a bowl-shaped portion, a portion 1 of the same diameter, a first variable-diameter portion 2, and a second variable-diameter portion 4 connected sequentially from top to bottom. A flow-guiding and separating block 5 is provided inside the second variable-diameter portion 4. An inlet hole 3 is defined by the inner wall of the portion 1 of the same diameter. The inlet hole 3 extends to the bottom of the first variable-diameter portion 2 and connects with the flow-guiding and separating block 5. The upper part of the flow-guiding and separating block 5 abuts against the bottom of the inlet hole inside the first variable-diameter portion 2. A flow-stabilizing structure is provided on the flow-guiding and separating block 5. The outlet of the inlet hole 3 is in the shape of an inverted trapezoid.

[0029] Example 1

[0030] like Figure 3 The diagram shown is a cross-sectional view of the submersible inlet provided in this embodiment. The flow stabilizing structure of this inlet is a flow stabilizing hole 6, which horizontally penetrates the flow guiding and separating block 5. The flow stabilizing hole 6 is located in the lower middle part of the flow guiding and separating block 5. The diameter of the outlet at both ends of the flow stabilizing hole 6 is larger than the diameter of the middle hole, and the flow stabilizing hole 6 horizontally penetrates the flow guiding and separating block 5.

[0031] In this embodiment, the bottom of the inlet hole 3 is directly connected to the flow guiding and separating block 5, and a flow stabilizing hole 6 is opened on the flow guiding and separating block. When the molten steel flows down from the inlet hole 3, it is directly diverted through the flow guiding and separating block 5. At the same time, the flow stabilizing hole 6 is opened on the flow guiding and separating block 5 to avoid uneven flow velocity of molten steel at the outlet, reduce the fluctuation of the liquid surface in the crystallizer, uniformly distribute the outflow from the outlet, prevent the entrapment of protective slag, and give full play to the effect of continuous casting.

[0032] Example 2

[0033] like Figure 4 The diagram shown is a cross-sectional view of the submersible inlet provided in this embodiment. The flow stabilizing structure disclosed in this embodiment includes a flow stabilizing vertical hole 8 disposed in the center of the flow guiding and separating block 5, and flow stabilizing branch holes 7 connected to the flow stabilizing vertical hole 8. The diameter of the flow stabilizing vertical hole 8 is larger than the diameter of the flow stabilizing branch holes 7. There are at least four flow stabilizing branch holes 7, which extend symmetrically and obliquely to the lower side of the flow guiding and separating block 5 in pairs. The outlet of the flow stabilizing branch holes 7 is located on the lower side of the flow guiding and separating block 5.

[0034] In this embodiment, the bottom of the inlet hole 3 is directly connected to the flow-guiding and separating block 5. The flow-stabilizing structure includes a flow-stabilizing vertical hole 6 located in the center of the flow-guiding and separating block 5 and a flow-stabilizing branch hole 7 connected to the flow-stabilizing vertical hole 6. The flow-guiding and separating block 5 is flat in shape. When the molten steel flows down from the inlet hole, it is directly diverted by the flow-guiding and separating block 5. At the same time, the molten steel is diverted along the flow-stabilizing vertical hole 6 inside the flow-guiding and separating block 5, so as to avoid uneven separation of the molten steel by the flow-guiding and separating block 5 and uneven flow velocity at the nozzle outlet. This reduces the fluctuation of the liquid surface in the crystallizer, can even outflow from the nozzle, prevent the entrapment of protective slag, and can give full play to the effect of continuous casting.

[0035] Example 3

[0036] like Figure 5 The diagram shown is a cross-sectional view of the flow-guiding and separating block 5 of the submersible nozzle provided in this embodiment. The flow-stabilizing structure in this embodiment is a spiral channel 9 arranged from top to bottom within the flow-guiding and separating block 5. The spiral channel 9 includes multiple layers of annular channels, with adjacent layers connected end-to-end. The spiral channel 9 includes a spiral channel inlet 10 and a spiral channel outlet 11. The spiral channel inlet 10 is located at the upper center of the flow-guiding and separating block 5 corresponding to the inlet hole 3, and the spiral channel outlet 11 is located at the lower center of the flow-guiding and separating block 5.

[0037] The upper inlet of the flow guiding and separating block 5 is arc-shaped with a radius of 15mm, and the diameter of the widest part of the flow guiding and separating block 5 is 76mm.

[0038] The spiral channel described in this embodiment includes a spiral channel inlet and a spiral channel outlet. The spiral channel inlet is located at the middle of the upper end of the flow-guiding and separating block, corresponding to the inlet hole. The spiral channel outlet is located at the middle of the lower end of the flow-guiding and separating block. As the molten steel flows down from the inlet hole, it is simultaneously divided into three streams. Two streams of molten steel are dispersed from both sides of the flow-guiding and separating block, while the third stream flows out from the spiral channel inside the separating block. This balances the inflow volume at the outlets on both sides of the flow-guiding and separating block, thus further preventing surface fluctuations due to large inflow volumes. The spiral channel reduces the impact force of the molten steel, making it less likely to cause surface fluctuations when reaching the outlet. The improvements provided by this invention can uniformly distribute the outflow from the nozzle, reduce surface fluctuations in the crystallizer, prevent the entrapment of protective slag, and fully utilize the continuous casting effect.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. An immersion-type sprue, comprising a sprue body, the sprue body comprising, from top to bottom, a bowl-shaped portion, a portion of the same diameter (1), a first variable-diameter portion (2), and a second variable-diameter portion (4), wherein a flow-guiding and separating block (5) is provided within the second variable-diameter portion (4), and an inlet hole (3) is defined by the inner wall of the portion of the same diameter (1), characterized in that, The inlet hole (3) extends to the bottom of the first variable diameter section (2) and connects to the flow guide and separation block (5). The upper part of the flow guide and separation block (5) abuts against the bottom of the inlet hole inside the first variable diameter section (2). A flow stabilizing structure is provided on the flow guide and separation block (5). The outlet of the inlet hole (3) is in the shape of an inverted trapezoid. The flow stabilizing structure is a flow stabilizing hole (6), which horizontally penetrates the flow guiding and separating block (5). The flow stabilizing structure includes a flow stabilizing vertical hole (8) located in the center of the flow guiding and separating block (5) and a flow stabilizing branch hole (7) connected to the flow stabilizing vertical hole (8). The diameter of the flow stabilizing vertical hole (8) is larger than the diameter of the flow stabilizing branch hole (7).

2. The immersion-type water inlet according to claim 1, characterized in that, The flow stabilizing hole (6) is located in the lower middle part of the flow guiding and separating block (5).

3. The immersion-type water inlet according to claim 2, characterized in that, The diameter of the outlet at both ends of the flow stabilizing hole (6) is larger than the diameter of the middle hole.

4. The submersible sprue according to claim 3, characterized in that, The flow stabilizing branch holes (7) are at least four in number and extend symmetrically in pairs to the lower side of the flow guiding and separating block (5). The outlet of the flow stabilizing branch holes (7) is located on the lower side of the flow guiding and separating block (5).

5. The submersible sprue according to claim 1, characterized in that, The flow stabilization structure is a spiral channel (9) arranged from top to bottom inside the flow guiding and separating block (5). The spiral channel (9) includes multiple annular channels, with the annular channels of adjacent layers connected end to end.

6. The submersible sprue according to claim 5, characterized in that, The spiral channel (9) includes a spiral channel inlet (10) and a spiral channel outlet (11). The spiral channel inlet (10) is located at the middle of the upper end of the flow separation block (5) corresponding to the inlet hole (3), and the spiral channel outlet (11) is located at the middle of the lower end of the flow separation block (5).

7. The submersible sprue according to claim 1, characterized in that, The upper inlet of the flow-guiding and separating block (5) is arc-shaped with a radius of 15mm, and the diameter of the widest part of the flow-guiding and separating block (5) is 76mm.

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