CN110997183A - Nozzle with a nozzle body - Google Patents
Nozzle with a nozzle body Download PDFInfo
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- CN110997183A CN110997183A CN201780093700.1A CN201780093700A CN110997183A CN 110997183 A CN110997183 A CN 110997183A CN 201780093700 A CN201780093700 A CN 201780093700A CN 110997183 A CN110997183 A CN 110997183A
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- flow control
- nozzle
- control portion
- width
- molten steel
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D41/00—Casting melt-holding vessels, e.g. ladles, tundishes, cups or the like
- B22D41/50—Pouring-nozzles
Abstract
The nozzle according to the invention comprises: a body unit having a passage through which molten steel may pass and having a discharge hole at a lower end portion thereof through which molten steel is discharged to the outside; and a flow control unit installed in the body unit so as to be formed around the body unit in an extending manner in an outward widthwise direction of the body unit. Thus, a nozzle according to an aspect of the present invention may reduce the melt surface velocity around the nozzle more than conventional nozzles. Therefore, when molten steel is supplied by applying a nozzle including a flow control unit according to an embodiment, bare steel in a molten surface around the nozzle is more reduced than in the related art, so that slag caused by the bare steel can be more suppressed or prevented from mixing with the molten steel than before, thereby enabling to limit or prevent the generation of inclusions.
Description
Technical Field
The present invention relates to a nozzle and more particularly to a nozzle capable of reducing inclusions.
Background
A general continuous casting apparatus includes: a tundish temporarily storing molten steel by receiving the molten steel through an injection nozzle connected to a ladle and then distributing the molten steel to each of continuous casting streams (strand); a nozzle supplying molten steel in a ladle to a tundish; a mold that first solidifies molten steel received from the tundish into a predetermined shape; a cooling zone including a plurality of rollers and cooling nozzles (not shown) that perform a series of operations to bend or straighten the slab while completing solidification by removing heat from the uncured slab.
When molten steel is injected into a nozzle connecting a ladle and a tundish, the molten steel is discharged into the tundish through a discharge hole defined at a lower end portion of the nozzle. The molten steel discharged from the nozzle forms an upward flow flowing in a direction toward a molten surface at an upper portion of the molten steel, and particularly, a strong upward flow is formed around the nozzle. In addition, strong turbulence is generated at the molten surface by the upward flow of molten steel, and the upward flow or turbulence pushes the slag around the nozzle. That is, the upward flow or turbulence of the molten steel pushes the slag from the nozzle. Thus, the nozzle 10 and the slag S are spaced apart from each other to produce bare steel. Bare steel is a major factor in the generation of inclusions and destabilizes the molten surface of the tundish, thereby causing slag to mix with molten steel.
Therefore, when molten steel is supplied to a tundish, research into a nozzle capable of reducing or limiting the generation of bare steel on a molten surface is required.
(related art documents)
Korean registered utility model No. kr0223846y1
Disclosure of Invention
Technical problem
The present disclosure provides a nozzle capable of reducing inclusions.
The present disclosure also provides a nozzle capable of limiting or preventing the production of bare steel at a molten surface.
Solution scheme
According to an exemplary embodiment, a nozzle comprises: a body part including a passage through which molten steel passes and a discharge hole through which molten steel is discharged to the outside and defined at a lower end portion of the body part; and a flow control portion mounted to the body portion and mounted to extend outward in a width direction of the body portion centering on the body portion.
The flow control portion may be arranged outside the discharge hole at the lower portion of the body portion.
The flow control portion may extend outwardly from an outer surface of the body portion, and a length of the flow control portion extending from the outer surface of the body portion may be greater than a thickness of a wall of the body portion.
The flow control part may have a hollow shape in which an area corresponding to the discharge hole is open, and an inner surface of the flow control part as a peripheral wall of the opening may be in contact with an outer peripheral surface of the body part.
A ratio ((a + F)/D) × 100)) of a sum of a width (a) of the flow control portion and a thickness (F) of a wall of the body portion to a width (D) of the channel of the body portion may be in a range from about 74% to about 125%.
A ratio (a/F) of a width (a) of the flow control portion to a thickness (F) of a wall of the body portion (110) may be in a range from about 2.1 to about 4.2.
Each of the opening of the flow control portion and the appearance of the flow control portion may have a shape that is at least one of a circular shape, an elliptical shape, and a polygonal shape.
The flow control portion may extend continuously along a circumferential direction of the body portion.
The bottom surface of the lower end portion of the body portion and the bottom surface of the flow control portion may be positioned at the same position as each other.
Advantageous effects
The nozzle according to the exemplary embodiment may reduce the melt surface velocity around the nozzle as compared to a typical nozzle. Therefore, when molten steel is supplied by applying the nozzle including the flow control portion according to the exemplary embodiment, bare steel at the molten surface around the nozzle is reduced as compared with a typical case. Therefore, since the feature that mixing of slag with molten steel due to bare steel can be suppressed or prevented as compared with the typical case, the generation of inclusions can be limited or prevented.
Drawings
Fig. 1 is a view illustrating a part of a continuous casting apparatus including a nozzle according to an exemplary embodiment.
Fig. 2 is a view for explaining bare steel generation when a typical nozzle is applied.
Fig. 3 is a view for explaining a flow control portion connected to a lower portion of a body portion in a nozzle according to an exemplary embodiment.
FIG. 4 is an experimental graph showing a melt surface velocity index according to a ratio of a sum of a thickness of a body or wall of a body part and a width of a flow control part to a width of a channel.
Fig. 5 is a cross-sectional view illustrating a flow control part according to an exemplary embodiment.
Fig. 6 to 13 are views showing the nozzle according to the first to eighth comparative examples and embodiments and the flow of molten steel when the nozzle is applied.
Detailed Description
Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings. This disclosure may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.
The present disclosure relates to the following nozzles: the nozzle can reduce the generation of inclusions when molten steel is transported or discharged by using the nozzle. More specifically, the present disclosure provides the following nozzles: the nozzle can reduce or prevent the generation of inclusions by reducing bare steel when molten steel in a ladle is supplied or transferred to a tundish by using the nozzle.
Hereinafter, a nozzle according to an exemplary embodiment will be described with reference to the accompanying drawings.
Fig. 1 is a view illustrating a continuous casting apparatus including a nozzle according to an exemplary embodiment. Fig. 2 is a view for explaining bare steel produced when a typical nozzle is applied. Fig. 3 is a view for explaining a flow control portion connected to a lower portion of a body portion in a nozzle according to an exemplary embodiment. FIG. 4 is an experimental graph showing a melt surface velocity index according to a ratio of a sum of a thickness of a body or wall of a body part and a width of a flow control part to a width of a channel. Fig. 5 is a cross-sectional view illustrating a flow control part according to an exemplary embodiment. Fig. 6 to 13 are views showing the nozzle according to the first to eighth comparative examples and embodiments and the flow of molten steel when the nozzle is applied.
Referring to fig. 1, the continuous casting apparatus includes: a ladle L in which molten steel M is stored; a tundish 200 receiving molten steel M from a ladle L; a nozzle 100 for supplying molten steel in the ladle L to the tundish 200; and a gate G (or a slide gate) that controls communication between the ladle L and the nozzle 100. Although not shown, the continuous casting apparatus further includes: a mold (not shown) that is disposed under the tundish 200 and receives molten steel from the tundish 200 to preliminarily cool the molten steel M; and a submerged nozzle (not shown) installed to connect the tundish 200 and the mold and to supply the molten steel M of the tundish 200 to the mold.
The ladle L is a unit for receiving the molten steel M and supplying the molten steel M to the tundish 200. A tap hole through which molten steel is discharged is defined at the bottom of the ladle L, and a nozzle 100 is connected to the tap hole.
Hereinafter, for convenience of description, a nozzle mounted to a ladle is referred to as a top nozzle, and a nozzle supplying molten steel passing through the top nozzle of the ladle L to a tundish is referred to as a "nozzle" as a bell nozzle in the present application.
When the gate G is opened, the molten steel in the ladle L is transferred to the nozzle 100 through the top nozzle TN and the gate G, and then discharged through an opening defined in a lower portion of the nozzle 100 and supplied into the tundish 200. The molten steel discharged from the discharge hole 113 of the nozzle 100 provides an ascending flow that flows in a direction toward the top surface of the molten steel. In particular, a strong upward flow is provided around the nozzle 100.
In addition, referring to fig. 2, strong turbulence is generated on the molten surface by the upward flow of the molten steel M, and the upward flow or turbulence pushes the slag S around the nozzle 10. That is, the molten steel M is pushed by the upward flow or turbulence of molten steel S centering on the nozzle 10. Accordingly, as shown in the enlarged view of fig. 2, bare steel is produced due to the nozzle 10 and the slag S being spaced apart from each other.
The bare steel is a main cause of the generation of inclusions, and the slag is mixed with the molten steel by destabilizing the molten surface of the tundish 200.
Accordingly, the exemplary embodiment provides the nozzle 100 that reduces bare steel generated when molten steel in the ladle L is supplied to the tundish 200.
Referring to fig. 1 and 3, a nozzle 100 according to an exemplary embodiment includes: a body part 110 including an inner space or passage through which molten steel may pass and a discharge hole 113 through which molten steel is discharged to the outside; and a flow control part 120 mounted to the body part 110 and extending in a direction of an outer width of the body part 110 centering on the body part 110.
The body part 110 includes: an inner space, i.e., a passage 112, extending in a vertical direction; and a main body 111 including a tap hole 113, the tap hole 113 being a lower opening through which molten steel is tapped. That is, the body part 110 includes: a main body 111 extending in a vertical direction; a passage, which is an empty space defined in the body 111, extending corresponding to the extending direction of the body 111; an inlet, which is an upper opening of the body 111 communicating with the passage 112; a discharge hole 113, which is a lower opening of the body 111 communicating with the passage 112. Herein, the body 111 may be referred to as a wall surrounding the inlet, the passage 112, and the discharge hole 113.
In addition, the width, thickness or outer diameter of the lower end portion of the body 111 or wall corresponding to the outer circumference of the discharge hole 113 may be greater than the width, thickness or outer diameter of the upper region of the body 111 or wall. Here, the lower end portion of the body portion 110 or the body 111 may be referred to as a flange.
When the configuration of the body part 110 according to an exemplary embodiment is described again, the body part 110 may include: a first nozzle 110a disposed below the gate G; a second nozzle 110b connected to a lower portion of the first nozzle 110 a; and a third nozzle 110c connected to a lower portion of the second nozzle 110 b.
A first nozzle 110a, which is commonly referred to as an intermediate nozzle, is arranged between the gate G and the second nozzle 110 b.
A second nozzle 110b, commonly referred to as a collector nozzle, is arranged between the first nozzle 110a and the third nozzle 110 c.
The third nozzle 110c, which is generally referred to as a cap nozzle, is installed such that a lower portion thereof is disposed in the tundish 200, and the third nozzle 110c supplies molten steel to the tundish. The lower portion of the third nozzle 110c (i.e., the cap nozzle) includes at least a section having a variable outer diameter or a section having a different outer diameter. That is, as shown in fig. 1 or 3, the lower portion of the third nozzle 110c includes: a first section 111a having an outer diameter that gradually increases in a downward direction; and a second section 111b extending in a downward direction from a lower portion of the first section 111a and having the same outer diameter as that of a lowermost end of the first section 111 a. Here, the outer diameter of the second section 111b may be larger than the outer diameter of the upper region of the first section 111 a. The second section 111b may be referred to as a flange.
All of the above-described first to third nozzles 110a, 110b and 110c may be individually separated and coupled to each other.
In addition, the lower end of the body part 110 according to an exemplary embodiment may be the third nozzle 110c, i.e., the lower end of the cap nozzle.
The flow control part 120 functions to restrict or prevent bare steel by: the flow rate of the molten steel discharged from the discharge hole 113 of the body part 110 is controlled or changed so as to reduce the flow velocity of the molten surface (or the velocity of the molten surface) compared to the typical flow velocity. The flow control part 120 extends from the lower end of the body part 110 in an outward direction of the body part 110, and the extending direction corresponds to a width direction of the body part 110. In other words, the flow control part 120 has a hollow plate shape in which an area corresponding to the discharge hole 113 of the body part 110 is opened, for example, a circular hollow shape. That is, the flow control portion 120 continuously extends in the circumferential direction from the outer portion of the body portion 110. In addition, the flow control portion 120 extends outward in the width direction of the body portion 110 centering on the opening, and connects an inner surface divided by the central opening to the body portion 110. Accordingly, the flow control part 120 extends in an outward direction from the lower portion of the body part 110, and the opening of the flow control part 120 is arranged to correspond to the discharge hole of the body part 110.
In addition, the bottom surface of the lower end portion of the body part 110 is positioned at the same position as the bottom surface of the flow control part 120.
As described above, when molten steel is supplied to the tundish 200 by using a typical nozzle that does not include a flow control portion, bare steel is generated as slag is pushed from a molten surface around the nozzle. Therefore, in order to reduce the generation of bare steel, it is necessary to further reduce the flow velocity around the nozzle when using a typical nozzle. In other words, when a typical nozzle that does not include the flow control portion 120 is used, the flow velocity of the melt surface is required to be less than 1 (refer to mathematical equation 1) by using a nozzle that improves on the flow velocity of the melt surface around the nozzle. That is, when a nozzle improved for the flow velocity of the melt surface around a typical nozzle that does not include the flow control portion 120 is used, the flow velocity of the melt surface is preferably less than 1 (refer to mathematical equation 1).
Here, when a nozzle improved for the flow velocity of the melt surface around a typical nozzle is used, the melt surface velocity ratio I around the nozzle may be referred to as a melt surface velocity index I, and when the melt surface velocity index I is less than 1, the flow velocity is reduced compared to the typical case, and thus bare steel is reduced.
[ mathematical equation 1 ]
In addition, the width a of the flow control portion 120 extending outward in the width direction from the body portion 110 is greater than the thickness F (a > F) of the wall or body 111 of the body portion 110, so that the melt surface velocity index I is less than 1 as described above. In other words, the length a of the flow control portion 120 extending outward from the body portion 110 is greater than the thickness F (a > F) of the main body 111 or the wall dividing the passage 112 or the discharge hole 113.
Here, the width a of the flow control part represents a spaced distance between an inner surface and an outer surface of the flow control part 120, and the inner surface of the flow control part 120 is connected to the body part 110. In other words, the width a is the separation distance between the outer surface of the body part 110 and the outer surface of the flow control part 120.
When the width a of the flow control part is described again by reflecting the above description, the length a between the inner surface and the outer surface of the flow control part 120 must be greater than the thickness F of the main body 111 of the body part 110 surrounding the discharge hole 113.
When the length from the inner surface to the outer surface of the flow control part 120, i.e., the width a of the flow control part 120 is less than the thickness F (F > a) of the main body part 110 surrounding the discharge hole 111, the melt surface velocity index I may be equal to 1 or greater than 1, the effect of reducing bare steel is reduced as compared with a typical case not including the flow control part 120, or bare steel similar to the typical case may be produced.
Generally, the opening degree between the top nozzle TN and the nozzle 100 at the time of starting or initiating the supply of molten steel in the ladle L to the tundish 200 is 100%, and the opening degree is adjusted to 50% after the start or initiation of the supply of molten steel. The opening degree can be controlled by the operation of the gate G.
In addition, as the opening degree increases, the amount of discharge per hour decreases. The flow velocity at the melt surface is relatively large when the discharge amount is relatively large, compared to when the discharge amount is relatively small. In addition, when a typical nozzle not including the flow control part 120 is used, bare steel is generated even when the opening degree is about 50%. Therefore, it is preferable that the opening degree of about 50% be used as a reference for calculating the melt surface speed index I.
In addition, in the exemplary embodiment, in order to effectively reduce the melt surface velocity around the body part 110 or make the melt surface velocity index I less than 1, the ratio of the sum (F + a) of the thickness F of the main body 111 of the body part 110 and the width a of the flow control part 120 to the inner diameter D of the body part 110, the width D of the passage 112, or the width D of the discharge hole 113 is adjusted (refer to mathematical equation 2).
[ mathematical equation 2 ]
Referring to fig. 4, when the ratio of the sum of the thickness F of the wall or body 111 of the body part 110 and the width a of the flow control part 120 (F + a) to the width D of the channel 112 is equal to or greater than 74% and equal to or less than 125%, the melt surface velocity index is less than 1. Therefore, the nozzle 100 is configured such that the ratio X of the sum (F + a) of the thickness F of the wall or main body 111 of the body portion 110 and the width a of the flow control portion 120 to the width D of the passage 112 is equal to or greater than 74% and equal to or less than 125%. In addition, when the value of the melt surface velocity index I is less than 1, the melt surface velocity index I is preferably in the range from about 85% to about 110% of the value.
As described above, at least one of the width D of the passage 112, the thickness F of the wall or body 111 of the body part 110, and the width a of the flow control part may be adjusted to adjust the ratio of the sum (F + a) of the thickness F of the wall or body 111 of the body part 110 and the width a of the flow control part 120 to the width D of the passage 112.
Here, the feature of additionally mounting the flow control portion 120 to the existing body portion or the cap nozzle is advantageous in terms of manufacturing cost. In this case, by adjusting the width a of the flow control portion 120 according to the thickness F of the wall of the existing body portion 110 and the width D of the channel 112, the ratio X of the sum (F + a) of the thickness F of the wall or main body 111 of the body portion 110 and the width a of the flow control portion 120 to the width D of the channel 112 may be in the range from about 74% to about 125%, preferably in the range from about 85% to about 110%. That is, by adjusting the width of the flow control part a according to the thickness F of the wall or body 111 of the body part 110 to be operated, the ratio X (X ═ T/(D)). 100%) of the sum (F + a) of the thickness F of the wall or body 111 of the body part 110 and the width a of the flow control part 120 to the width D of the channel 112 may be in the range from about 74% to about 125%, preferably in the range from about 85% to about 110%.
Alternatively, the body portion 110 and the flow control portion 120 may be separately manufactured according to the specification of the casting apparatus without using an existing body portion or a cap nozzle. Even in this case, by adjusting the width a of the flow control part 120 according to the thickness F of the wall of the body part 110 and the width D of the channel 112, the ratio X (X ═ T/(D)). 100%) of the sum (F + a) of the thickness F of the wall or the body 111 of the body part 110 and the width a of the flow control part 120 to the width D of the channel 112 is in the range from about 74% to about 125%.
To this end, the ratio (a/F) of the width a of the flow control portion 120 to the thickness F of the wall or body 111 of the body portion 110 is adjusted to be in the range from about 2.1 to about 4.2. That is, when the ratio (a/F) of the width a of the flow control part 120 to the thickness F of the wall or body 111 of the body part 110 is in the range from about 2.1 to about 4.2, the ratio X (X ═ T/(D)) -100%) of the sum (F + a) of the thickness F of the wall or body 111 of the body part 110 and the width a of the flow control part 120 to the width D of the channels 112 of the body part 110 may be in the range from about 74% to about 125%.
Therefore, in the exemplary embodiment, when the ratio (a/F) of the width a of the flow control portion 120 to the thickness F of the wall or body 111 of the body portion 110 is set in the range from 2.1 to 4.2, the ratio X (X ═ T/(D)) -100%) of the sum (F + a) of the thickness F of the wall or body 111 of the body portion 110 and the width a of the flow control portion 120 to the width D of the channel 112 is set in the range from about 74% to about 125%. Therefore, when molten steel is supplied by using the nozzle 100 according to the exemplary embodiment, the melt surface velocity index I is less than about 1, and bare steel at the melt surface around the body portion 110 is reduced or limited.
In the flow control portion according to the exemplary embodiment, each of the opening and the outer appearance of the flow control portion has a circular shape as in (a) of fig. 5. However, the exemplary embodiments are not limited to the shape of the flow control portion. For example, the flow control portion may have various shapes. Also, the appearance of the body portion is not limited to the circular shape. The body part may have various polygonal shapes, such as a rectangular shape, and the opening of the flow control part may have various shapes, such as a rectangular shape, in addition to a circular shape, according to the external appearance of the body part.
More specifically, the flow control part 120 may have a circular opening and an elliptical appearance (refer to (b) of fig. 5), a circular opening and a rectangular appearance (refer to (c) of fig. 5), and a circular opening and a rectangular appearance (refer to (d) of fig. 5). In addition, the flow control part 120 may have a rectangular opening and a circular appearance (refer to fig. 5 (e)), a rectangular opening and an elliptical appearance (refer to fig. 5 (f)), a rectangular opening and a square appearance (refer to fig. 5 (g)), and a square opening and a rectangular appearance (refer to fig. 5 (h)).
In the case of the flow control portion in (a) of fig. 5, when the flow control portion has a circular shape and a circular appearance instead of an elliptical shape, the spaced distance between the inner surface and the outer surface of the flow control portion 120 is constant regardless of the position.
However, in the case of the shape of the flow control part 120 according to the exemplary embodiment in fig. 5B to 5H, the spaced distance between the inner surface and the outer surface may be different according to the measurement point.
Therefore, when the flow control part 120 according to the exemplary embodiment in fig. 5B to 5H is applied, it is necessary to specify which portion is the width a of the flow control part 120 when adjusting the ratio X of the sum (F + a) of the thickness F of the wall or main body 111 of the body part 110 and the width a of the flow control part 120 to the width D of the channel 112.
In an exemplary embodiment, the maximum separation distance between a tangent line passing through the inner surface of the flow control portion and a tangent line passing through the outer surface of the flow control portion is designated as the width a. Here, the apex of the opening or the appearance is not included.
Hereinafter, the width a of the flow control portion 120 according to the exemplary embodiment in fig. 5B to 5H will be described.
In the flow control part 120 according to another exemplary embodiment of fig. 5 (b), the maximum distance among the separation distances between the inner surface and the outer surface of the flow control part 120 is the width a of the flow control part 120. That is, the maximum distance among the spaced distances between a first tangent line passing through one point of the circular inner surface and a second tangent line passing through the elliptical outer surface while facing the first tangent line is the width a of the flow control portion 120.
In addition, when at least one of the opening and the external appearance has a polygonal shape as in fig. 5 (c) to (h), the spacing distance between the vertices of the inner surface and the outer surface is not the width a of the flow control portion 120. In other words, when the opening has a circular shape and the external appearance has a polygonal shape (refer to (c) and (h) of fig. 5), the distance between the first tangent line passing through the inner surface of the flow control portion 120 and the tangent line passing through the vertex of the outer surface is not the width a of the flow control portion 120. In this case, the maximum distance among the spaced distances between a first tangent line passing through the inner surface of the flow control part 120 and a second tangent line passing through one side of the outer surface to face the first tangent line is the width a of the flow control part 120.
In addition, when the opening has a polygonal shape and the external appearance has a circular shape (refer to (e) to (f) of fig. 5), the spacing distance between the vertex of the inner surface and the outer surface is not the width a of the flow control portion 120. In this case, the maximum distance among the spaced distances between a first tangent line passing through one side portion of the flow control portion except the vertex and a second tangent line passing through the outer surface while facing the first tangent line is the width a of the flow control portion 120.
For another example, when the opening and the outer appearance all have a polygonal shape (refer to (g) and (h) of fig. 5), the spaced distance between the vertex of the inner surface and the vertex of the outer surface of the flow control part 120 is not the width a of the flow control part 120. In this case, the maximum distance among the spaced distances between a first tangent line passing through one side portion of the flow control portion except the vertex and a second tangent line passing through one side portion of the outer surface except the vertex while facing the first tangent line is the width a of the flow control portion 120.
Hereinafter, the melt surface speed and whether bare steel is generated according to the exemplary nozzle and the nozzle according to the exemplary embodiment will be described with reference to fig. 6 to 14.
As shown in fig. 14, the nozzle according to the exemplary embodiment includes a body part 110 that injects molten steel into a tundish and a flow control part 120 that extends from a lower end of the body part 110 in a width direction of the body part 110. Here, the flow control part 120 has an open hollow shape at the center thereof, and the flow control part 120 is connected to the body part 110 such that the lower end or the discharge hole 113 of the body part is arranged to correspond to the central opening. That is, the inner surface of the flow control part 120 is connected to the outer surface of the body part 110. And, a ratio X of a sum (F + a) of a thickness F of the wall or the body 111 of the body part 110 and a width a of the flow control part 120 to a width D of the passage 112 is equal to or more than 74% and equal to or less than 125%.
The first and second comparative examples in fig. 6 and 7 include a nozzle that does not include a flow control portion according to an exemplary embodiment. Here, when the first nozzle (top nozzle) communicates with the second and third nozzles (intermediate nozzle and cap nozzle) through the gate, the first comparative example is a case where the first nozzle (top nozzle) communicates with the second and third nozzles (intermediate nozzle and cap nozzle) by about 50% (about 50% open), and the second comparative example is a case where the first nozzle (top nozzle) communicates with the second and third nozzles (intermediate nozzle and cap nozzle) by about 100% (about 100% open).
The nozzles according to the third to sixth comparative examples in fig. 8 to 11 include a body part 10 injecting molten steel into a tundish, and a flow control part 12 is separately provided in the tundish below a discharge hole of the body part 10. That is, the nozzles according to the third to sixth comparative examples do not include the flow control portion as the flow control portion according to the exemplary embodiment, and the flow control portion 12 according to the third to sixth comparative examples is separated from the body portion 10. Also, the flow control part 12 according to the third to sixth comparative examples may have an area corresponding to the discharge hole of the body part 10, the area having an open hollow shape, and the size of the opening of the flow control part 12 may be smaller than the size of the discharge hole of the body part 10. And, the lower end of the body portion 10 is spaced apart from the flow control portion 12.
Here, the flow control portion 12 according to the third comparative example has a shape extending in the width direction or the left-right direction.
In addition, the flow control portion 12 according to the fourth and fifth comparative examples may have the following shape: wherein a flow control portion extending in the vertical direction (hereinafter referred to as a second flow control portion) is connected to a lower portion of a flow control portion extending in the left-right direction (hereinafter referred to as a first flow control portion) as in the third comparative example. Here, the flow control portion 12 according to the fourth comparative example has the following shape: wherein the second flow control portion is disposed at a portion corresponding to an inner side of an outer surface of the bottom surface of the first flow control portion. In addition, the flow control portion 12 according to the fifth comparative example has the following shape: wherein the second flow control portion is connected to an outermost surface of the first flow control portion, and a hole through which molten steel may pass is defined in the second flow control portion. Here, the hole may have a shape inclined upward in an outward direction of the flow control portion 12.
The flow control portion 12 according to the sixth comparative example has a shape having a convex curvature in the upward direction while being inclined downward from the body portion 10 in the outward direction.
The nozzle according to the seventh and eighth comparative examples in fig. 12 to 13 includes a body part 10 that injects molten steel into a tundish, and a flow control part 12 is separately provided below a discharge hole of the body part 10 in the tundish. Here, the flow control portion 12 according to the seventh and eighth comparative examples is mounted to the bottom surface of the tundish and has a shape protruding toward the discharge hole. Also, the flow control portion 12 according to the seventh comparative example protrudes in the direction of the discharge hole, and has a shape with a curvature, such as a semicircular shape. The flow control portion 12 according to the eighth comparative example has a shape with a diameter gradually decreasing in the direction of the discharge hole and with a sharp uppermost end, for example, a triangular shape.
The flow control portion 12 according to the third to eighth comparative examples described above is separated or spaced apart from the body portion 10, instead of being connected to the body portion 10 as described above. Also, the flow control portion 12 according to the third to eighth comparative examples is not configured such that the ratio of the sum of the thickness F of the body or wall of the body portion and the width a of the flow control portion (F + a) to the width D of the passage 112 is equal to or greater than about 74% and equal to or less than about 125%.
According to the first to eighth comparative examples and exemplary embodiments, the melt-surface flow velocity was measured for each of the nozzles. This experiment was performed so that the molten surface speed around the nozzle was detected when molten steel was supplied to the tundish by applying each of the above-described nozzles according to the first to eighth comparative examples and exemplary embodiments. With about 50% open as in the first comparative example, the discharge amount from the nozzle was about 48 kg/s. In the case where about 100% is open as in the second to eighth comparative examples, the discharge amount from the nozzle is about 100 kg/s. In addition, as shown in table 1, the melt surface velocity index I was calculated by calculating the ratio of the melt surface velocities when the nozzles according to the second to sixth comparative examples and the exemplary embodiment were applied based on the flow velocity of the first comparative example in the case where about 50% was open.
The flow tendency of molten steel discharged from the nozzle may be detected from the thermal image data in each of fig. 6 to 14.
[ TABLE 1 ]
The third to eighth comparative examples all had a melt surface velocity index I equal to or greater than about 1. That is, although the flow control portions were installed as in the third to eighth comparative examples, the melt-surface speed was greater than that of the first comparative example not including the flow control portions. Therefore, when the nozzles and the flow control portions according to the third to eighth comparative examples were applied, a larger amount of bare steel than that of the first comparative example not including the flow control portion may be generated.
However, when the flow control portion is connected to the body portion as in the exemplary embodiment, the melt surface velocity index I is about 0.62, that is, about less than 1, which is significantly reduced as compared with the melt surface velocity index I of the first comparative example. Therefore, when molten steel is supplied by applying the nozzle including the flow control portion according to the exemplary embodiment, bare steel at the molten surface around the nozzle is reduced as compared with the first comparative example including the typical nozzle. Therefore, compared with the typical case, the feature that slag is mixed with molten steel due to bare steel can be restricted or prevented, and thus inclusions can be restricted or prevented.
INDUSTRIAL APPLICABILITY
According to the nozzle according to the exemplary embodiment, the melt surface velocity around the nozzle may be reduced compared to the melt surface velocity of a typical nozzle. Therefore, when molten steel is supplied by applying the nozzle including the flow control portion according to the exemplary embodiment, bare steel at the molten surface around the nozzle is reduced as compared with a typical case. Therefore, since the feature that slag is mixed with molten steel due to bare steel can be suppressed or prevented as compared with the typical case, the generation of inclusions can be limited or prevented.
Claims (9)
1. A nozzle, comprising:
a body part including a passage through which molten steel passes and a discharge hole through which molten steel is discharged to the outside and defined at a lower end thereof; and
a flow control portion mounted to the body portion and mounted to extend outward in a width direction of the body portion centering on the body portion.
2. The nozzle of claim 1, wherein the flow control portion is disposed outside of the discharge orifice at a lower portion of the body portion.
3. The nozzle of claim 1, wherein the flow control portion extends outwardly from an outer surface of the body portion, and a length of the flow control portion extending from the outer surface of the body portion is greater than a thickness of a wall of the body portion.
4. The nozzle according to claim 2, wherein the flow control portion has a hollow shape in which an area corresponding to the discharge hole is open, and an inner surface of the flow control portion as a peripheral wall of the opening is in contact with an outer peripheral surface of the body portion.
5. The nozzle of any of claims 1 to 4, wherein a ratio ((A + F)/D) 100)) of a sum of a width (A) of the flow control portion and a thickness (F) of a wall of the body portion to a width (D) of a channel of the body portion is in a range from about 74% to about 125%.
6. The nozzle of claim 5, wherein a ratio (A/F) of a width (A) of the flow control portion to a thickness (F) of the wall of the body portion (110) is in a range from about 2.1 to about 4.2.
7. The nozzle of claim 4, wherein each of the opening of the flow control portion and the appearance of the flow control portion has a shape that is at least one of a circular shape, an elliptical shape, and a polygonal shape.
8. The nozzle according to any one of claims 1 to 7, wherein the flow control portion extends continuously along a circumferential direction of the body portion.
9. The nozzle according to any one of claims 1 to 7, wherein a bottom surface of the lower end portion of the body portion and a bottom surface of the flow control portion are positioned at the same position as each other.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR10-2017-0100452 | 2017-08-08 | ||
| KR1020170100452A KR101969105B1 (en) | 2017-08-08 | 2017-08-08 | Nozzle |
| PCT/KR2017/014397 WO2019031660A1 (en) | 2017-08-08 | 2017-12-08 | Nozzle |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110997183A true CN110997183A (en) | 2020-04-10 |
Family
ID=65271412
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201780093700.1A Pending CN110997183A (en) | 2017-08-08 | 2017-12-08 | Nozzle with a nozzle body |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JP6972302B2 (en) |
| KR (1) | KR101969105B1 (en) |
| CN (1) | CN110997183A (en) |
| WO (1) | WO2019031660A1 (en) |
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| CN1136787A (en) * | 1993-12-06 | 1996-11-27 | 罗宁·麦金公司 | Antivortexing nozzle system for pouring molten metal |
| KR19980033105U (en) * | 1996-12-06 | 1998-09-05 | 김종진 | Immersion Opening Nozzle |
| JP2009090322A (en) * | 2007-10-09 | 2009-04-30 | Furukawa Sky Kk | Continuous casting machine and continuous casting method |
| AU2010274474B2 (en) * | 2009-07-24 | 2012-11-29 | Krosakiharima Corporation | Nozzle for discharging molten metal |
| CN202667641U (en) * | 2012-06-14 | 2013-01-16 | 鞍钢股份有限公司 | Anti-flocculation upper water nozzle of tundish of air curtain |
| CN203459651U (en) * | 2013-08-13 | 2014-03-05 | 宝山钢铁股份有限公司 | Submersed nozzle with flow control vanes |
| CN204842961U (en) * | 2015-08-21 | 2015-12-09 | 安徽工业大学 | Get rid of immersion nozzle of inclusion |
| CN206083842U (en) * | 2015-07-02 | 2017-04-12 | 维苏威坩埚公司 | A part piece for controlling come from stream of fire -resistant container |
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|---|---|---|---|---|
| JPH0114386Y2 (en) * | 1984-09-18 | 1989-04-26 | ||
| JPS62146553U (en) * | 1986-03-10 | 1987-09-16 | ||
| JPS6362251U (en) * | 1986-10-04 | 1988-04-25 | ||
| JPH0673725B2 (en) * | 1989-04-04 | 1994-09-21 | 住友金属工業株式会社 | Immersion nozzle and continuous casting method using the same |
| JP2895281B2 (en) * | 1991-10-18 | 1999-05-24 | 川崎製鉄株式会社 | Treatment of residual slag in tundish |
| JPH08155600A (en) * | 1994-12-07 | 1996-06-18 | Nippon Steel Corp | Apparatus for continuously casting molten metal |
| KR200223846Y1 (en) | 1996-12-12 | 2001-06-01 | 이구택 | Slag mixing prevention nozzle |
| KR101185012B1 (en) * | 2005-03-22 | 2012-09-21 | 주식회사 포스코 | A device for preventing molten iron from scattering and foreign substances from floating up |
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2017
- 2017-08-08 KR KR1020170100452A patent/KR101969105B1/en active IP Right Grant
- 2017-12-08 CN CN201780093700.1A patent/CN110997183A/en active Pending
- 2017-12-08 WO PCT/KR2017/014397 patent/WO2019031660A1/en active Application Filing
- 2017-12-08 JP JP2020505872A patent/JP6972302B2/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1136787A (en) * | 1993-12-06 | 1996-11-27 | 罗宁·麦金公司 | Antivortexing nozzle system for pouring molten metal |
| KR19980033105U (en) * | 1996-12-06 | 1998-09-05 | 김종진 | Immersion Opening Nozzle |
| JP2009090322A (en) * | 2007-10-09 | 2009-04-30 | Furukawa Sky Kk | Continuous casting machine and continuous casting method |
| AU2010274474B2 (en) * | 2009-07-24 | 2012-11-29 | Krosakiharima Corporation | Nozzle for discharging molten metal |
| CN202667641U (en) * | 2012-06-14 | 2013-01-16 | 鞍钢股份有限公司 | Anti-flocculation upper water nozzle of tundish of air curtain |
| CN203459651U (en) * | 2013-08-13 | 2014-03-05 | 宝山钢铁股份有限公司 | Submersed nozzle with flow control vanes |
| CN206083842U (en) * | 2015-07-02 | 2017-04-12 | 维苏威坩埚公司 | A part piece for controlling come from stream of fire -resistant container |
| CN204842961U (en) * | 2015-08-21 | 2015-12-09 | 安徽工业大学 | Get rid of immersion nozzle of inclusion |
Also Published As
| Publication number | Publication date |
|---|---|
| JP6972302B2 (en) | 2021-11-24 |
| KR101969105B1 (en) | 2019-04-15 |
| JP2020530813A (en) | 2020-10-29 |
| KR20190016344A (en) | 2019-02-18 |
| WO2019031660A1 (en) | 2019-02-14 |
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