KR101789572B1 - Nozzle unit - Google Patents

Abstract

A non-contact section is formed between a first nozzle and a second nozzle in a section where a first nozzle and a second nozzle overlap each other. And the seal member between the nozzles constituting the unit can be increased by including a binder which fills the gap between the first nozzle and the second nozzle.
That is, a noncontact section is formed in a part of the fastening section of the collecting nozzle and the shroud nozzle so that the gap between the collecting nozzle for moving the molten steel and the shroud nozzle can be filled with the solidification of molten steel (now). By forming the projections for moving the molten steel to the lower portion of the shroud nozzle toward the non-contact section, a part of the molten steel moving through the nozzle can be moved to the non-contact section to fill the gap.
As such, the communication between the inside of the nozzle and the outside can be filled with the solidification of the molten steel, and maintenance of the additional configuration used for filling the gap between the nozzles is not required. Further, the occurrence of reoxidation of the molten steel due to the incorporation of the outside air into the nozzle can be reduced, and the problem of the deterioration of the cleanliness of the molten steel due to the reoxidization of the molten steel can be solved.

Description

A nozzle unit (nozzle unit)

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a nozzle unit, and more particularly, to a nozzle unit capable of increasing the sealability between nozzles constituting the unit.

Generally, a continuous casting facility is a continuous casting process in which slabs are produced by refining in a steelmaking process, feeding molten steel stored in a ladle, temporarily storing the molten steel in a tundish, supplying the molten steel to a mold, . Here, the molten steel is supplied from the ladle to the tundish through a path formed by fastening a collect nozzle and a shroud nozzle at the bottom of the ladle.

At this time, a gap is inevitably formed at the joint portion between the shroud nozzle and the collect nozzle. Oxygen in the air sucked through the gap oxidizes the molten steel by reacting with the molten steel. The nitrogen is dissolved into the molten steel to increase the nitrogen concentration in the molten steel .

As a result, the quality of the molten steel transferred to the tundish becomes very weak, and molten steel oxidized by the generation of nonmetallic inclusions due to oxidation of molten steel causes clogging of the nozzle injecting molten steel into the mold, thereby interrupting the continuous casting process It causes problems. This leads to a problem of causing many defects in the finally produced cast slab.

Conventionally, a gasket is inserted between a collect nozzle and a shroud nozzle in order to prevent air from being sucked through a nozzle fastening part, and a method of minimizing the oxygen atmosphere by sealing the periphery with Ar (argon) The increase of the upward pressure of the shroud is used to increase the adhesion between the coarse nozzle and the shroud nozzle.

However, since the gasket used in the former method is excellent in adhesion at the time of initial use due to its physical characteristics, there is a problem that the number of maintenance is increased due to breakage of the gasket during transportation of the ladle or reuse of the collect nozzle.

JP 1996-243695 A KR 2004-0028189 A KR 0843861 B1

The present invention provides a nozzle unit capable of sealing a passage through which outside air permeates into molten steel.

The present invention provides a nozzle unit in which installation of a gasket between nozzles is not required.

The present invention provides a nozzle unit capable of suppressing and preventing oxidation of molten steel to improve the cleanliness of molten steel.

A nozzle unit according to an embodiment of the present invention includes a first nozzle and a second nozzle each forming a passage, and a non-contact portion between the first nozzle and the second nozzle in a section where the first nozzle and the second nozzle overlap each other And a binder for filling the space between the first nozzle and the second nozzle.

The non-contact section may be formed below the section where the first nozzle and the second nozzle overlap.

The non-contact section may be formed by recessing the first nozzle and the second nozzle from a surface facing the first nozzle and the second nozzle.

A main protrusion protruding from the inner surface of the nozzle toward the center of the nozzle may be disposed at a position spaced downward from the end of the step at the nozzle disposed outside the first nozzle and the second nozzle.

The nozzles disposed inside the first nozzle and the second nozzle may be provided with auxiliary protrusions protruding outward from the nozzles.

The widths of the main protrusions and the auxiliary protrusions may decrease from the top to the bottom.

The distance between the main protrusion and the step portion may be smaller than the total height of the non-contact portion.

At least a part of the auxiliary protrusions may protrude from the non-contact section.

The binding material may comprise the same material as the treatment through the passageway.

The process product passing through the passageway includes molten steel, the molten steel is a solidified molten steel, and the first nozzle and the second nozzle may each include a shroud nozzle and a collect nozzle. .

According to the nozzle unit according to the embodiment of the present invention, it is possible to seal the gap between the plurality of nozzles without any separate structure, thereby reducing the problem caused by re-oxidation of the molten steel.

That is, a noncontact section is formed in a part of the fastening section of the collecting nozzle and the shroud nozzle so that the gap between the collecting nozzle for moving the molten steel and the shroud nozzle can be filled with the solidification of molten steel (now). By forming the projections for moving the molten steel to the lower portion of the shroud nozzle toward the non-contact section, a part of the molten steel moving through the nozzle can be moved to the non-contact section to fill the gap.

As such, the communication between the inside of the nozzle and the outside can be filled with the solidification of the molten steel, and maintenance of the additional configuration used for filling the gap between the nozzles is not required. Further, the occurrence of reoxidation of the molten steel due to the incorporation of the outside air into the nozzle can be reduced, and the problem of the deterioration of the cleanliness of the molten steel due to the reoxidization of the molten steel can be solved.

1 is a schematic view showing a part of a continuous casting facility equipped with a nozzle unit according to an embodiment of the present invention.
2 is a view for explaining a fastening method of a nozzle unit according to an embodiment of the present invention.
3 is an enlarged partial perspective view of a nozzle unit according to an embodiment of the present invention.
4 is a cross-sectional view of Fig.
5 is a sectional view for explaining an auxiliary projection provided in the nozzle unit of the present invention.
6 is an enlarged cross-sectional view of a nozzle unit according to a modification of the present invention.
7A and 7B are views illustrating a method of penetrating a binder using a nozzle unit according to an embodiment of the present invention.
8 is a view showing a state in which a binder is sealed in a nozzle unit according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be embodied in various different forms, and it is to be understood that these embodiments are merely illustrative of the principles of the invention and are not intended to limit the scope of the invention to those skilled in the art. It is provided to let you know completely.

The nozzle unit according to the embodiment of the present invention has a structure for easily sealing the fastening portion between the plurality of nozzles constituting the unit with the solidified material of the processed product and no separate structure is required at the fastening portion, Thereby increasing the sealing performance. Hereinafter, in the present invention, the plurality of nozzles constituting the nozzle unit may be a shroud nozzle and a collect nozzle provided in a continuous casting facility, and the solidified material of the processed material may be now solidified molten steel.

Hereinafter, a nozzle unit according to an embodiment of the present invention will be described with reference to FIGS. 1 to 8. FIG. 1 is a schematic view showing a part of a continuous casting facility equipped with a nozzle unit according to an embodiment of the present invention. 2 is a view for explaining a fastening method of a nozzle unit according to an embodiment of the present invention. 3 is an enlarged partial perspective view of a nozzle unit according to an embodiment of the present invention. 4 is a cross-sectional view of Fig. 5 is a sectional view for explaining an auxiliary projection provided in the nozzle unit of the present invention. 6 is an enlarged cross-sectional view of a nozzle unit according to a modification of the present invention. 7A and 7B are views illustrating a method of penetrating a binder using a nozzle unit according to an embodiment of the present invention. 8 is a view showing a state in which a binder is sealed in a nozzle unit according to an embodiment of the present invention.

The nozzle unit 100 according to the embodiment of the present invention includes a first nozzle 110 and a second nozzle 130 forming a passage and a second nozzle 110 and a second nozzle 110, 130, respectively. Here, the step portion 150 forms a non-contact portion between the first nozzle 110 and the second nozzle 130 in a region where the first nozzle 110 and the second nozzle 130 are overlapped to form a sealing region 155 ).

Hereinafter, the continuous casting facility 1 will be briefly described, and then the nozzle unit 100 will be described in detail.

The continuous casting facility 1 is a facility for transferring molten steel M refined from a converter (not shown) to the ladle 10 and producing it as a cast steel. The molten steel M contained in the ladle 10 is rotated Is stored in the dish (30) and then injected and drawn into a mold (50) disposed under the tundish (30) to be produced as a cast. At this time, when the molten steel M is supplied from the ladle 10 to the tundish 30, a path through which the molten steel M moves through the nozzle unit 100 is formed.

The nozzle unit 100 is provided to provide a path for moving the molten steel M and may be extended from the ladle 10 to the tundish 30 so as to block the contact between the molten steel M and the outside . That is, the nozzle unit 100 provides a moving path of the molten steel M so that the molten steel M can be moved from the ladle 10 to the tundish 30 in an environment where the molten steel M is blocked to the maximum extent with external air. Hereinafter, the moving path of the molten steel is a shroud nozzle (hereinafter referred to as " first nozzle ") formed by extending from the lower portion of the ladle 10 to the tundish 30 to a collect nozzle The first path W1 of the first nozzle 110 and the second nozzle 130 of the first nozzle 110 are moved upward by the upper wall of the first nozzle 110 and the inner wall of the second nozzle 130, And the second path W2 of the second path W2.

In the embodiment of the present invention, the outermost nozzle out of the first nozzle 110 and the second nozzle 130 is designated as the second nozzle 130 and will be described. However, the first nozzle 110 may be disposed at the outermost position.

The engaging section 170 refers to a section H1 which is overlapped by the insertion of the first nozzle 110 and the second nozzle 130 and includes a flange 150 described later. That is, the fastening section 170 indicates a portion where almost all the surfaces between the first nozzle 110 and the second nozzle 130 are in contact with each other in a section where the first nozzle 110 and the second nozzle 130 overlap each other And can exhibit a bonding region in which a very fine gap is present.

The first jaw part 150 is provided between the first nozzle 110 and the second nozzle 130 in a coupling section 170 where the first nozzle 110 and the second nozzle 130 overlap, To form the region 155. That is, the step portion 150 is formed at a lower portion of the fastening section 170 where the first nozzle 110 and the second nozzle 130 are overlapped with each other, and the first nozzle 110 and the second nozzle 130, The first nozzle 110 and the second nozzle 130 may be recessed from the facing surface. Hereinafter, the step portion 150a formed in the first nozzle 110 and the step portion 150b formed in the second nozzle 130 will be described.

3 and 4, the step 150 may form a step on the first nozzle 110 to form a sealing region 155 between the second nozzle 130 and the step. The step portion 150 has a first step formation surface 153a and a movement path W in the same direction to the movement path W in order to make the diameters of the upper portion and the lower portion different from each other in the outer peripheral surface of the first nozzle 110, And a step formed on the first nozzle 110. The second step forming surface 151a is formed in a direction intersecting the first nozzle forming surface 151a.

6, the step 150b forms a step on the second nozzle 130 to form a sealing region 155 between the first nozzle 110 and the first nozzle 110. As shown in FIG. Thus, the step portion 150b is recessed from the inner surface of the second nozzle 130 toward the outer side so that the first step formation surface 153b in the same direction as the movement path W and the first step formation surface 153b in the direction crossing the movement path Stage forming surface 151b to form a step on the second nozzle 130. As shown in FIG.

Hereinafter, the nozzle unit 100 of the present invention will be described with reference to the step unit 150a shown in Figs. 3 and 4. Fig. However, the configurations described below can also be applied to the step unit 150b shown in Fig. 6, and the roles of the configurations are the same.

As such, the first step-forming surface 153 is disposed to face the inner surface of the second nozzle 130 at a position spaced apart from the inner surface of the second nozzle 130 by a predetermined distance, 155 are formed. At this time, the sealing region 155 is formed by solidifying the molten steel passing through the first nozzle 110 and the second nozzle 130 so that the minute gap between the first nozzle 110 and the second nozzle 130 The sealing region 155 may be formed on the lower side from the center with respect to the total height of the section H1 where the first nozzle 110 and the second nozzle 130 overlap. That is, the sealing region 155 is formed at the lower portion of the first nozzle 110 so that the molten steel M can be easily introduced between the first nozzle 110 and the second nozzle 130.

The distance t between the first step formation surface 153 of the first nozzle 110 and the inner surface of the second nozzle 130 is set to be larger than the width t of the sealing region 155 in the direction crossing the passage direction, And may have a distance in the range of more than 3 mm to less than 7 mm. That is, the forming width of the sealing region 155 is desired to be within a range of more than 3 mm and less than 7 mm, because the width of the molten steel can be easily introduced into the sealing region 155. At this time, if the width (mm) of the sealing region 155 has a value of 3 mm or less, the molten steel infiltration state into the sealing region 155 is poor and the formation of solidified molten steel (hereinafter referred to as & It is not easy to seal the gap between the first nozzle 110 and the second nozzle 130. If the width (mm) of the sealing region 155 is 7 mm or more, the penetration of molten steel into the sealing region 155 is satisfactory. However, when the molten steel M is injected into the first nozzle 110 and the second nozzle It is not easy to seal the gap between the first nozzle 110 and the second nozzle 130 because the molten steel M is filled in the sealing region 155 at the initial stage via the first nozzle 110 and the second nozzle 130.

That is, the sealing state of the sealing region according to the width (mm) of the sealing region through the following Table 1 will be described. Table 1 shows the distance (mm) between the first step formation surface 153 of the first nozzle 110 and the inner surface of the second nozzle 130 of the nozzle unit 100 according to the embodiment of the present invention, The determination result is shown according to the molten steel infiltration state and the present formation state in the sealing region 155.

Sealing area width (mm) Molten steel infiltration state Now forming state Remarks One Bad Dense density now incongruity 3 Good Some bad incongruity 5 Good Good fitness 7 Good Dense density now incongruity

In Table 1, when the width (mm) of the sealing region 155 is set to 1 mm, the width (mm) of the sealing region 155 is too narrow and the permeability of the molten steel into the sealing region 155 is low. Thus, the present density formed in the sealing region 155 is reduced, resulting in a defect that the formation is not dense at this time. When the width (mm) of the sealing area 155 is set to 3 mm, penetration of molten steel into the sealing area 155 is easier than when the width (mm) of the sealing area 155 is 1 mm, Resulting in a defect in the state of being formed in the sealing region 155 that is not densely formed. When the width (mm) of the sealing region 155 is set to 7 mm, the molten steel can easily permeate into the sealing region 155, but the amount of molten steel required to flow into the sealing region 155 increases do. Therefore, the method in which the molten steel flows into the sealing region 155 is automatically performed by the flow of the molten steel passing through the path formed by the nozzle unit 100, so that the sealing region 155 having the width of 7 mm Inflow is not enough. Therefore, it can be confirmed that the widths (mm) of the sealing region 155 are unsuitable because the forming state is not formed densely in the sealing region 155.

However, when the width (mm) of the sealing area 155 is set to 5 mm, it is easy to penetrate the molten steel M into the sealing area 155, and it can be confirmed that the formed state is also good.

Meanwhile, in the nozzle disposed outside of the first nozzle 110 and the second nozzle 130, a main protrusion 140 protruded inward from the inner surface of the nozzle disposed outside.

The main protrusion 140 protrudes inward from the inner surface of the second nozzle 130 in the second nozzle 130 so that the molten steel M supplied to the moving path can be introduced into the sealing area 155 And serves to induce the movement of the molten steel (M). That is, the main protrusion 140 may be formed in a ring shape such that almost a part of the outer surface of the main protrusion 140 can contact the inner surface of the second nozzle 130, And the inner diameter of the second nozzle 130 at a position connected to the second nozzle 130.

The main protrusion 140 is spaced apart from the sealing region 155 at a distance A3 smaller than the value A2 based on the total height A2 in the passage direction of the sealing region 155 . At this time, the height of the main protrusion 140 decreases from one end to the other end of the both ends, which contact the second nozzle 130, so that the molten steel M colliding with the upper surface of the main protrusion 140 The molten steel which does not collide with the upper surface of the main protrusion 140 can be easily moved downward of the second nozzle 130. [

More specifically, the main protrusion 140 is in contact with the inner surface of the second nozzle 130 at a position spaced downward from a section where the first nozzle 110 and the second nozzle 130 are overlapped, do. The main protrusion 140 is spaced apart from the overlapping portion of the first nozzle 110 and the second nozzle 130 by a distance having a value smaller than the formation height in the direction of the passage of the sealing region 155 . The reason why the main protrusion 140 is positioned is that the molten steel supplied to the passage collides with the upper surface of the main protrusion 140 and flows into the sealing area 155 easily. That is, even if the molten steel M collides against the upper surface of the main protrusion 140, the molten steel M may be damaged when the main protrusion 140 is spaced apart from the sealing region 155 by a height greater than the height of the sealing region 155 in the passage direction. The inside of the sealing region 155 can not be easily reached, and thus the inside of the sealing region 155 can not be formed densely.

The main protrusion 140 has a shape decreasing in height from one end to the other end connected to the inner surface of the second nozzle 130. The main protrusions 140 are connected to the second nozzles 130 to resist the load of the molten steel while the main protrusions 140 are removed by the load at the other end So as to prevent and inhibit it.

4, the nozzle unit 100 of the present invention is provided with an auxiliary (not shown) protruding from the outer side surface to the outer side surface of the nozzle disposed on the inside of the first nozzle 110 and the second nozzle 130, The protrusions 160 may be provided.

The auxiliary protrusions 160 protrude outward from the outer surface of the first nozzle 110 in the first nozzle 110. The molten steel M supplied to the moving path is sealed by the main protrusions 140 in the sealing area 155, it plays a role to restrain and prevent the molten steel introduced back from moving downward. That is, the auxiliary protrusions 160 may be formed in a ring shape in which almost a part of the inner surface of the auxiliary protrusions 160 comes into contact with the outer surface of the first nozzle 110 where the step portions 150 are formed. The inner diameter may be the inner diameter of the first nozzle 110 at a position where the auxiliary protrusion 160 is connected to the first nozzle 110.

The auxiliary protrusion 160 is connected to the first step formation surface 153 forming the step 150 in the outer surface of the first nozzle 110 so that the auxiliary protrusion 160 is formed in the sealing area 155 . The auxiliary protrusion 160 may be connected to the first nozzle 110 at a position outside the region where the passage of the first nozzle 110 and the passage of the second nozzle 130 communicate with each other at the lower end of the first nozzle 110 . The molten steel impinging on the upper surface of the main protrusion 140 is prevented from being automatically moved downward by the gravity after the molten steel enters the sealing region 155, The molten steel can be easily solidified in the sealing region 155.

More specifically, the auxiliary protrusion 160 may be provided at one end of the auxiliary protrusion 160 in contact with the first step formation surface 153, or may have a top surface in contact with the lower surface of the first nozzle 110. At this time, the positions where the auxiliary protrusions 160 are mounted are not limited in the bottom surfaces of the first step formation surface 153 and the first nozzle 110. However, when the upper surface of the auxiliary protrusion 160 is connected to the lower surface of the first nozzle 110, the amount of the falling molten steel colliding with the main protrusion 140 is lowered by the gravity toward the first step forming surface 153 can be reduced as compared with when auxiliary protrusions 160 are formed.

The auxiliary protrusion 160 has a shape in which the height decreases from one end connected to the outer surface to the first nozzle 110 toward the other end. That is, the auxiliary protrusion 160 has a shape whose height is reduced in a direction opposite to the main protrusion 140. In the region where the molten steel M enters the sealing region 155 so that the auxiliary projection 160 does not obstruct the movement of the auxiliary projection 160 on the path of the molten steel M coming into the sealing region 155 from the main projection 140, So as to minimize the area occupied by the battery 160.

Hereinafter, a steel manufacturing process using the nozzle unit according to the embodiment of the present invention will be briefly described with reference to FIG.

First, a path is formed in the first nozzle 110 below the ladle 10 by a tundish 30 to refine the furnace and be received in the ladle 10 and cast molten steel delivered to the continuous casting installation 1 The second nozzle 130 is tightened. At this time, a sealing region 155 is formed between the first nozzle 110 and the second nozzle 130 by fastening the first nozzle 110 and the second nozzle 130.

When the fastening of the first nozzle 110 and the second nozzle 130 is completed, the slide gate (not shown) under the ladle 10 is opened to allow the molten steel M contained in the ladle 10 to flow through the first nozzle And moves along the path formed by the first nozzle 110 and the second nozzle 130 to be stored in the tundish 30.

At the same time as the molten steel M is moved to the tundish 30, the molten steel passing through the first path among the molten steel moving along the path formed by the first nozzle 110 and the second nozzle 130 And part of the second nozzle 130 collides with the main protrusion 140 mounted on the inner surface of the second nozzle 130. The molten steel M impinging on the main protrusion 140 flows into the upper portion of the main protrusion 140, that is, into the sealing region 155 to form the first nozzle 110 and the second nozzle 110 constituting the sealing region 155, And rapidly starts to solidify due to the temperature of the heat exchanger 130. The molten steel M introduced into the sealing region 155 is coagulated by heat transfer to the first and second nozzles 110 and 130 having a relatively lower temperature than the temperature of the molten steel M, In the region 155, now (S) is formed by molten steel.

Since the present S formed between the first nozzle 110 and the second nozzle 130 fills a minute gap formed between the first nozzle 110 and the second nozzle 130, The movement of the molten steel to the tundish 30 can be continued in a state in which the communication with the outside of the nozzle unit 100 is blocked.

As described above, the nozzle unit according to the embodiment of the present invention does not require a separate structure for preventing the gap between the first nozzle and the second nozzle constituting the nozzle unit. That is, some of the molten steel passing through the first nozzle and the second nozzle flows into the space between the first nozzle and the second nozzle and solidifies, thereby sealing the gap between the first nozzle and the second nozzle. This does not require a conventionally used gasket, and can easily prevent the gap. Accordingly, it is possible to reduce the cost required for maintenance and repair of the gasket, prevent foreign air from flowing into the nozzle gap, and increase the cleanliness of the molten steel. Thus, the overall productivity and efficiency of the steel production process can be increased.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the following claims.

100: nozzle unit 110: first nozzle
130: second nozzle 150, 150b:
140: main projection 160: auxiliary projection

Claims (10)

A first nozzle and a second nozzle each forming a moving path of molten steel,
A step portion forming a non-contact section between the first nozzle and the second nozzle in a section where the first nozzle and the second nozzle overlap; And
And a binder for flowing into the non-contact section and filling the gap between the first nozzle and the second nozzle,
Wherein the step portion is formed by recessing the first nozzle and the second nozzle from the facing surface in any one of the first nozzle and the second nozzle. The method according to claim 1,
Wherein the non-contact section is formed below the section where the first nozzle and the second nozzle overlap. delete The method according to claim 1 or 2,
And a main protrusion protruding from the inner surface of the nozzle toward the center of the nozzle is disposed at a position spaced downward from the end of the step at the nozzle disposed outside the first nozzle and the second nozzle. The method of claim 4,
And a sub-projection formed on an inner side of the first nozzle and the second nozzle, the sub-projection being formed outwardly of the nozzle. The method of claim 5,
Wherein the width of each of the main protrusion and the auxiliary protrusion decreases from the top to the bottom. The method of claim 4,
And the distance between the main protrusion and the step portion is smaller than the total height of the non-contact portion. The method of claim 5,
And at least a part of the auxiliary projection is protruded from the non-contact section. The method according to claim 1,
Wherein the binder comprises the same material as the molten steel. The method of claim 2,
The binder is a solidified molten steel,
Wherein the first nozzle and the second nozzle each include a shroud nozzle and a collect nozzle.

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