Art
[1]The present invention relates to a nozzle and more particularly to a nozzle capable of reducing the inclusions.
BACKGROUND
[2]Typical continuous casting machine is when supplied with molten steel through an injection nozzle connected to the ladle through the nozzle, a tundish for feeding a tundish (tundish), the molten steel of the below that distributed to each strand (strand), save the molten steel is temporarily in the tundish passing the initial solidification to receive the molten steel to a constant-sheet mold (mold), and US while away the heat from the solidified cast complete solidification plurality of rolls to perform a series of operations to bend the slab or spreads (roll) and a cooling nozzle which (not shown in ) and a cooling zone comprising a.
[3]
On the other hand, when injecting the molten steel in the ladle and the tundish nozzle to connect, the molten steel through the discharge port provided at the lower end of the nozzle is discharged into the tundish. The molten steel is discharged from a nozzle to form a rising current that flows in the molten steel top surface direction, in particular, the strong upward flow is formed around the nozzle. Then, by the upward flow of the molten steel so there is a strong turbulence in the bath surface, and Me is a rising flow or a turbulent flow to push the slag surrounding the nozzle. That is, the molten steel rising flow or a turbulence pushes the slag around the nozzle. Thus, the nozzle 10 and slag (S) is a simple natang spaced (Nude steel) is generated. These natang is a factor that causes the inclusions to destabilize the tundish bath surface, and cause to be incorporated into the molten slag.
[4]
Therefore, when supplying the molten steel into the tundish, there is a need for research on the nozzle capable of reducing or inhibiting the occurrence in the bath surface natang.
[5]
(Prior Art)
[6]
Korea Utility Model Registration Publication KR0223846Y1
Detailed Description of the Invention
SUMMARY
[7]
The present invention provides a nozzle which can reduce the inclusions.
[8]
The present invention provides a nozzle that can suppress or prevent the occurrence natang the bath surface.
Problem solving means
[9]
Nozzle body according to the invention provided with a discharge port which molten steel wherein molten steel discharged to the outside passing through the passage as possible and at the bottom; And a flow control unit mounted to the body portion to be formed extending to the center portion of the body into the body portion outer width direction; and a.
[10]
The flow controller is installed at an outer side of the discharge port at the bottom of the body portion.
[11]
The flow control member extends outwardly from the outside face of the body portion, a length of the flow control section extending from the outer surface of the body portion is preferably larger in thickness of the body wall.
[12]
The flow controller is a shape of the hollow area, the opening corresponding with the discharge port, it is preferred that the inner surface of the flow control wall around the opening, which is installed to be in contact with the outer peripheral surface of the body portion.
[13]
The body agreed rate of unit width (A) of the body portion wall thickness (F) and the flow control of the width (D) of the passage ((A + F) / D) * 100) is more than 74% at 125 to% or less.
[14]
That the ratio (A / F) of the width (A) of the flow control for the thickness (F) of said body portion (110) wall is 2.1 or more and 4.2 or less.
[15]
The flow controller may be the opening and the external shape one of a circular, oval, polygonal.
[16]
The flow control member is formed continuously extending along the circumference of the body portion.
[17]
The position of the bottom surface of the bottom surface of the lower end of the body portion and the flow control is equal to each other.
Effects of the Invention
[18]
According to the nozzle according to the embodiment of the present invention, it is possible to reduce the flow rate of the bath surface around the nozzle compared to prior art. Thus, when supplying the molten steel by applying a nozzle having a flow control unit according to the embodiment, natang in the bath surface around the nozzle is reduced in comparison with the prior art. Because of this, due to there natang slag can be suppressed or prevented as compared with the conventional to be incorporated into the molten steel, it is possible to suppress or prevent the occurrence of inclusions.
Brief Description of the Drawings
[19]
Figure 1 is a view of the portion of the continuous casting plant comprising a nozzle according to an embodiment of the present invention
[20]
Figure 2 is a view for explaining the natang generated during the conventional nozzle application
[21]
3 is in the nozzle according to the embodiment of the present invention, the view illustrating the flow control unit connected to the lower body portion
[22]
Figure 4 is a graph showing the experimental bath surface flow velocity in accordance with the index of non-agreement of the body or body thickness and the flow control part of the wall to the width of the passage width
[23]
5 is a transverse cross-sectional view of a flow controller in accordance with embodiments of the present invention
[24]
6 to 13 is a view of the nozzle and the molten steel flow at the time of its application according to the first to eighth comparative examples and Examples
Mode for the Invention
[25]
Hereinafter, description will be given of an embodiment of the present invention; However, the present invention is not limited to the embodiments set forth herein will be embodied in many different forms, but the embodiments are the scope of the invention to those skilled in the art, and the teachings of the present invention to complete It will be provided to fully inform.
[26]
The present invention is to transfer the molten steel, or ejected by a nozzle, to a nozzle for reducing the inclusions occur. More particularly, the present invention relates to sikineunde supply or transferred to a turn-dish by using the nozzle of a molten steel in the ladle, by reducing the natang occur, and provides a nozzle which can reduce or prevent the occurrence of inclusions resulting.
[27]
With reference to the drawings, a description will be given of a nozzle according to an embodiment of the invention.
[28]
1 is a view showing a continuous casting plant having a nozzle according to an embodiment of the invention. 2 is a view for explaining the natang generated during the conventional nozzle application. 3 is in the nozzle according to an embodiment of the present invention, a view illustrating the flow control unit connected to the lower body portion. Figure 4 is a graph showing the experimental bath surface flow velocity in accordance with the index of non-agreement of the body or body thickness and the flow control part of the wall to the width of the passage width. Figure 5 is a transverse cross-sectional view of a flow controller in accordance with embodiments of the present invention. 6 to 13 is a view showing the nozzle and the molten steel flow at the time of its application according to the first to eighth comparative examples and examples.
[29]
[30]
1, the continuous casting plant is molten steel; the molten steel in the (molten steel M) ladle that store (L), the tundish 200, and the ladle (L) being supplied to the molten steel (M) from the ladle (L) and a tundish (200) nozzle (100), the ladle (G), the gate (or a sliding gate) for controlling communication between (L) and the nozzle (100) to be supplied to. In addition, although not shown, the tundish 200 is disposed at the bottom, with the mold the mold (not shown), the tundish 200 to primary cooling the molten steel (M) receiving offer the molten steel from the tundish 200 It is provided so as to connect between, and includes an immersion nozzle (not shown) for supplying the molten steel (M) of the tundish 200 to the mold.
[31]
Ladle (L) comprises means, the ladle (L) bottom is provided with a tapped obtain the discharge of the molten steel can, the nozzle (100 in the tapping port for providing a dish 200 turns it to take the molten steel (M), and ) it is connected.
[32]
In for convenience of description below, a nozzle mounted on the ladle top nozzle the nozzle as naming, and supplying the molten steel passing through the top nozzle of the ladle (L) to the turn-dish (Top nozzle) as a shroud nozzle, in the present It is named as "nozzle".
[33]
The gate (G) is a, the ladle (L) a molten steel in a top nozzle (TN) and the gate (G) being transferred to the nozzle 100 through the nozzle opening that is a discharge port 113 provided with the lower (100) when the open It is discharged from and supplied into the tundish 200. The molten steel discharged from the discharge port 113 of the nozzle 100 is formed in the upward flow in the molten steel flowing direction and the top surface, in particular, the strong upward flow is formed around the nozzle 100.
[34]
And, Referring to Figure 2 there is to be a strong turbulence in the bath surface by the upward flow of the molten steel (M) occurs, the rising flow or a turbulent flow is me pushing the slag (S) around the nozzle 10. That is, the molten steel (M) pushes the slag (S) rising flow or a turbulence around the nozzle 10. Thus, the enlarged as help, the nozzle 10 and slag natang (Nude steel) is (S) spaced liver shown in Figure 2 is generated.
[35]
These natang is a factor for generating the inclusions, to destabilize the tundish 200 bath surface, causing the slag to be entrained into the molten steel.
[36]
Therefore, in the embodiment of the present invention to supply the molten steel in the ladle (L) to the tundish 200, and provides a nozzle (100) for reducing the occurrence natang.
[37]
1 and 3, the nozzle 100 in accordance with an embodiment of the present invention is provided with a body portion (110 discharge port 113, the inner space or passage, and the molten steel to the bottom as possible the molten steel passes to be discharged to the outside ) and comprises a flow controller (120) mounted to the body portion 110 such that, centered on the body portion 110 is formed extending outward in the width direction of the body 110. the
[38]
The body portion 110 includes a space that is, the passage 112 is provided, the molten steel (M) is ejected downward an opening discharge port 113 is provided with main body 111 that is formed extending in the vertical direction therein. That is, the body portion 110 to the empty space provided within the formed body 111, body 111 extends in the vertical direction, passage 112, passage 112 extending to extend corresponding to the direction of the main body 111 in communication with the main body 111 includes a body 111, an opening the lower discharge port 113 is communicated with the upper side an opening and the inlet passage (112). Here, the body 111 may be referred to as the peripheral wall surrounding the inlet passageway 112 and discharge port 113. The
[39]
Then, the width, thickness or diameter of the base of the body 111 or to the wall around the discharge port 113 may be greater than in the upper region. Thus, it is also possible to name a lower end flange spleen body portion 110 or the body 111.
[40]
Again describe the configuration of the body portion 110 in accordance with an embodiment, is connected to the lower portion of the first nozzle (110a), the first nozzle (110a), a body portion 110 that is located below the gate (G) of claim the second nozzle (110b), it is possible to include a third nozzle (110c) connected to the lower portion of the second nozzle (110b).
[41]
The first nozzle (110a) is located between the intermediate nozzle to be labeled as normal (middle nozzle), the gate (G) and the second nozzle (110b).
[42]
A second nozzle (110b) is a nozzle for being named conventional collector nozzle (collector nozzle), connected to a first nozzle (110a) and the third nozzle (110c).
[43]
A third nozzle (110c) is a nozzle for being called normal shroud nozzle (nozzle shroud) installed lower portion is positioned within the tundish 200, and supply the molten steel in the tundish. At least the lower portion of the nozzle 3 (namely, the shroud nozzle) (110c) have different sections or that its outer diameter is variable. That is, as shown in Fig. 1 or Fig. 3, the lower portion of the third nozzle (110c) extends from the bottom of the first section (111a), a first section (111a) formed so as to gradually increase the outer diameter in the downward direction to the lower side the interval to be a second region (111b) is formed to have the same outer diameter as the outer diameter of the bottom of the first section (111a). Here, the outer diameter of the second section (111b) may be referred to as the second section (111b) is a flange, greater than the outer diameter of the upper region of the first section (111a).
[44]
The first through the third nozzle (110a, 110b, 110c) described above are all individually separated and interlocking.
[45]
And the lower end of the body portion 110 in accordance with an embodiment of the present invention can be a third nozzle (110c), i.e., the lower end of the shroud nozzle.
[46]
[47]
The flow control unit 120 has a function of, by reducing to control or change the flow of the discharged molten steel from the discharge port 113 of the body portion 110, than the flow rate of the bath surface (or a bath surface speed) in the prior art, suppress or prevent natang and the. This flow control unit 120 is formed extending in the lateral direction of the body portion 110 from the lower body portion 110, the extension direction corresponds to the width direction of the body portion 110. In other words, the flow control unit 120 is a hollow shape of a discharge port 113, the opening of the hollow plate (plate) shape, for example, a circular area corresponding to the body portion (110). That is, the flow control unit 120 is formed continuously extending in the peripheral direction on the outer side of the body portion 110. Then, the flow control unit 120 and around the opening, is formed extending in the transverse direction outside of the body portion 110, the inner surface defining a central opening is connected to a body portion 110. The Thus, the flow control unit 120, while the opening is located corresponding to the discharge port of the body portion 110, is provided from a lower portion of the body portion 110 to the structure extending in a lateral direction.
[48]
In addition, the position of the bottom surface of the bottom surface of the lower end of the body portion 110 and the flow control unit 120 is equal to each other.
[49]
And, when using the conventional nozzle has the flow control is not installed to supply the molten steel in the tundish 200 and is pushed out of the slag from the bath surface around the nozzle natang occurs as described above (see FIG. 2 up). Thus, it order to reduce the occurrence natang use conventional nozzle time signal, it is necessary to reduce the bath surface flow velocity in the vicinity of the nozzle. If this in other words, it is necessary to ensure that the flow controller 120 is a conventional nozzle drive, an improved nozzle drive bath surface flow velocity to the flow rate of the nozzle around the bath surface is less than 1 are not provided (see Equation 1). That is, it is preferable that the value of the flow control unit 120 is a an improved nozzle relative to the conventional flow rate of the nozzle around the bath surface is not installed drive bath surface flow velocity is less than 1 (see equation 1).
[50]
Here, the bath surface flow rate ratio (I) around the improved nozzle drive, a nozzle for the bath surface flow velocity close to the conventional nozzle may be referred to as a bath surface flow velocity index (I), when the bath surface flow velocity index 1 is less than the flow rate over the prior It is reduced, whereby the natang is reduced accordingly.
[51]
Equation 1
[52]
[53]
Then, the main body (111 of this bath surface flow velocity index (I) is to be larger than 1, the width (A) of the flow control portion 120 extending in the transverse direction outwardly from the body portion 110. The body portion 110 ) or is greater than the wall thickness (F) (a> F). Different length (A) of words, the passage 112 or the flow controller 120 extends outwardly from the body portion 110 relative to body 111 or the thickness (F) of the wall defining the outlet opening (113) is formed so that the road (a> F).
[54]
The width of the flow control part, where (A) means the distance between the inner surface and the outer surface of the flow control unit 120 is connected to the body portion (110). If this in other words, the separation distance between the outer surface of the outer surface of the flow control section 120 of the body portion 110. The
[55]
The main body of the lower back described with respect to the width (A) of the flow controller to reflect this, the flow control unit 120 the length (A) has a body portion 110 surrounding the peripheral discharge port 113 in the inner surface to the outer surface of the ( of 111) is greater than the thickness (F).
[56]
On the other hand, little if compared with the thickness (F) of the wall of the flow control unit 120 length i.e., the flow control unit 120 the width (A) to surround the discharge port surrounding a body portion 110 of in the inner surface to the outer surface of the (F> a), bath surface flow velocity index (I) is 1 or more, or, the natang reduction effect than the conventional without the flow controller 120 is small, a similar natang the prior art can be generated.
[57]
In general, and the opening ratio between the ladle (L) Initially the top nozzle (TN) to the beginning or start of the supply in the tundish 200 the molten steel in the nozzle 100 to 100%, the opening ratio after the molten steel supplied to the initial or start the controls to 50%. Opening rate can be controlled by operation of the gate (G).
[58]
Then, the discharge amount per hour, was the less the greater the opening ratio, when the discharge amount is relatively small when compared to many, the greater the flow rate of the bath surface is relative. And a nozzle drive that is not provided with a flow control unit 120 as in the prior art, even when the opening is 50% is natang occurs near the nozzle. Thus, by obtaining the bath surface flow velocity index (I), it is preferable that at the time of 50% open.
[59]
[60]
In addition, effectively reducing the bath surface flow velocity around the body portion 110, or the bath surface flow velocity in order to ensure that the index is less than one, the width of the width (D) or passage 112 of the discharge port 113. In the embodiment of the present invention ( D) or the width (a) of the body portion 110 of the inner diameter (D) (hereinafter, the width (D in passage) thickness (F) and a flow control section 120 of body portion 110, main body 111 of the) the adjusted ratio of the sum (F + a) (see equation 2).
[61]
Equation (2)
[62]
[63]
4, the ratio of the sum (F + A) of the body portion 110, body 111, or the thickness (F) of the wall and the flow width (A) of the control section for the width (D) of the passage (112) when more than 74%, 125% or less, a bath surface flow velocity index is less than one. Therefore, the ratio of the embodiment, the Access sum (F + A) of the body unit 111 or the width (A) of thickness (F) and the flow control unit 120 of the wall to the width (D) of 112 ( to form the nozzle 100, such that X) is 74% or more and less than 125%. And, so that preferably over 85%, 110%, the bath surface flow velocity index (I) being of a value less than 1, so as to have a lower value of them (see Fig. 4).
[64]
The sum (F + A) of width (A) of the body portion 110, body 111, or the thickness (F) and the flow control unit 120 of the wall to the width (D) of the passage 112, as described above the ratio (X), the width of the passage 112 to the control (D), at least one of the body portion 110, body 111, or the thickness (F) of the wall and the width (a) of the flow control unit can be adjusted.
[65]
In this case, to install additional flow control unit 120 to the existing body or shroud nozzle is advantageous in terms of the manufacturing cost. In this case, the width of the width (D) and by regulating the width (A) of the flow control unit 120 according to the thickness (F) of the wall, the passage 112 in the passage 112 of the conventional body portion 110 ( D) a body portion 110, main body 111 or the sum (F + a) of the thickness (F) and flow width (a) of the control section of the wall ratio (X = (T / (D)) * 100% for ) is such that 74% or more and 125% or less, preferably 85% or more, less than 110%. In other words, adjusting the width (A) of the flow control unit 120 along with a body portion 110, main body 111 or the wall thickness to carry out operation (F) produced by, for the width (D) of the passage (112) the main body of the body portion 110, 111 or non-(X = (T / (D)) * 100% of the sum (F + a) of width (a) of thickness (F) and the flow control unit 120 of the wall ) is such that 74% or more and 125% or less, preferably 85% or more, less than 110%.
[66]
Of course, without using a conventional body portion 110 or a shroud nozzle, according to the specifications of the casting plant, a body portion 110 and the flow control unit 120, each can be manufactured separately. Likewise, even when the same, by adjusting the width (A) of the flow control unit 120 in accordance with the width (D) and thickness (F) of the wall of the passageway 112 of the body portion 110, the width of the passage (112) a body portion 110, main body 111 or the sum (F + a) of the thickness (F) and flow width (a) of the control section of the wall of the (D) of the non-(X = (T / (D)) * 100 %) is such that 74% or more and less than 125%.
[67]
To this end, the body portion 110, body 111, or the ratio of the width (A) of the flow control unit 120 to the thickness (F) of the wall (A / F) of 2.1 or more, the control is less than or equal to 4.2. In other words, when less than a body portion 110, body 111, or the ratio of the width (A) of the flow control unit 120 to the thickness (F) of the wall (A / F) of 2.1 or more, 4.2, body portion 110 passage body 110 main body 111 or the sum (F + a) of width (a) of thickness (F) and the flow control unit 120 of the wall to the width (D) of 112 non-(X = a is a (T / (D)) * 100%) is more than 74% and less than 125%.
[68]
Accordingly, the embodiment of the present invention, body portion 110, body 111, or the ratio of the width (A) of the flow control unit 120 to the thickness (F) of the wall (A / F) of 2.1 or more and 4.2 or less the ratio (X of the sum (F + a) of the body portion 110, body 111, or the thickness (F) of the wall and the flow width (a) of the control section for the width (D) of the passage (112) such that = (T / (D)) * 100%) is more than 74%, and is less than or equal to 125%. Accordingly, the embodiment and the example is less than 1, the flow velocity index (I) bath surface at the time of molten steel supplied by the nozzle 100 in accordance with, which results or natang is reduced compared with the conventional in the surrounding bath surface body portion 110, is suppressed.
[69]
Flow controller according to the first embodiment of the present invention is a circle as shown in Figure 5a the shape of the opening and the exterior. However, without the shape of the flow control part it is not limited to this and may be modified into various shapes. In addition, the exterior shape of the body is not limited to circular, it may be a variety of polygonal, for example rectangular, the opening of the flow control member can be a variety of shapes, for example, changed in a variety of polygons, such as rectangles in addition to a circular external shape along the body portion.
[70]
More specifically, the flow controller 120 while having the opening of the circular appearance oval or (see Fig. 5b), while having an aperture of circular appearance, square, or (see FIG. 5c), while having an aperture of a circular appearance rectangular or may be a (see Fig. 5d). Further, while having an opening of rectangular appearance is circular or (see FIG. 5e), while having an opening of rectangular appearance, oval, or (see FIG. 5f), while having an aperture of square exterior square or a (see Fig. 5g), while having the opening of the square may be in a rectangular appearance (see Fig. 5h).
[71]
As with the flow control unit shown in Figure 5a, it is the same regardless of the spacing distance between the position of the inner and outer surfaces when the opening and the external shape circular all non-elliptical, and the flow controller 120.
[72]
However, even if the shape of the flow control unit 120 according to the embodiments of Figure 5b to 5h, one separation distance between the side surface and the other surface may be different depending on the measuring point.
[73]
Thus, when applying a flow control unit 120, in accordance with the embodiment of Figure 5b to Figure 5h, a body portion 110, body 111, or the thickness (F) of the wall to the width (D) of the passage (112) in regulating the ratio (X) between the sum (F + a) of width (a) of the flow control unit 120, it is necessary to specify whether the where the width (a) of the flow controller 120.
[74]
According to an embodiment of the present invention will be of a spacing distance between the tangent line passing through the tangent with the outer surface through the inner surface of the flow control section, the maximum distance in the width (A) of the flow controller 120. In this case, the corner points of the openings or the appearance is excluded.
[75]
It will be described with respect to the width (A) of the flow control unit 120, in accordance with the following, the embodiment shown in Figure 5b to Figure 5h.
[76]
In the flow control unit 120 according to the present invention in the second embodiment of Figure 5b, and the maximum distance of the spacing distance between the inner and outer surfaces of the flow control unit 120 in the width (A) of the flow control unit 120 . That is, the circular and the inner surface of the first tangent passing through a point of the width of the first of the spaced distance between the first tangent line that passes through the elliptical outer face while facing a tangential, flow control unit 120, the maximum distance (A) It shall be.
[77]
And, FIGS. 5c to when at least one of a shape of the opening and the exterior polygon as 5h, not the width (A) of the distance between the flow control unit 120 and spaced apart from the inner surface and the outer surface of the corner. Other words, the opening is circular and when the appearance is polygonal (Fig. 5c and 5d), the flow in through the side of the first tangent and the other flow control the distance between the tangent line passing through the corner point of the side surface (120 of the controller 120 ) is not in the width (a) of. In this case, the flow control unit 120 within and passing through the side surface the first tangent, the first tangent and the face's outer width of the spacing between the second tangent line that passes through the side of the side surface, the maximum distance the flow control unit (A of ) as the.
[78]
In addition, the opening is a polygon, when the facade is circular (see Fig. 5e and 5f), no clearance between the inner surface and the outer surface of the corner points in the width (A) of the flow controller 120. Thus, the first tangent and the first second spaced distances of the flow control unit 120 the maximum separation distance between the tangent line that passes through the outer side while facing the tangent line passing through the sides other than the corner points of the flow control unit 120 when: and a width of (a).
[79]
In another example, not the width (A) of the opening and the exterior when all polygons (Fig. 5g and 5h), flow controller 120, the inner surface flow to the separation distance between the vertex and the outer surface of the corner of the control unit 120 of. In such a case, flow from the first tangent through the sides other than the corner points of the control unit 120, the first the separation distance of one, the maximum distance between the second tangent line that passes through the sides other than the corner points of the outer surface while facing the tangent and the width (a) of the flow controller 120.
[80]
[81]
With reference to Figure 6 to Figure 14, the description will be made on the bath surface flow velocity and natang occurrence of the nozzle and the conventional nozzle in accordance with an embodiment of the present invention.
[82]
And performed as the nozzle is according to the example shown in Figure 14, body portion (110) for injecting molten steel in the tundish, the flow is formed so as to extend from the lower outer side of the body portion 110 in the width direction of the body portion 110 and a controller (120). Wherein the flow control unit 120 is installed such that the center is a shape of a hollow-type opening, the lower end or the discharge port 113 of the body portion (110) connected to the body portion 110 so as to correspond to positions on the central opening. That is, the inner surface of the flow control unit 120 is connected to the outer surface of the body portion 110. Then, the sum (F a width (A) of the body portion 110, body 111, or the thickness (F) and the flow control unit 120 of the wall to the width (D) of the passage 112 of the body portion 110 ratio (X) of the + a) that was configured so that at least 74%, 125%.
[83]
On the other hand, the first and second comparative example shown in Figs. 6 and 7 is a nozzle 11 without a configuration corresponding to the flow control of the present invention. Wherein the first nozzle (top nozzle) and the second and third nozzle through a gate in sikineunde communication between (middle nozzle and a shroud nozzle), a first comparative example of the first nozzle (top nozzle) and the second and third when the nozzle (nozzle intermediate the nozzle and the shroud) a 50% communicating (50% open), and the second comparative example is the case of 100% (100% opening).
[84]
The third to sixth comparison nozzle according to the example of turn and the dish comprises a body portion (10) for injecting the molten steel, the turn-dish separate flow to the discharge opening below the body portion 10 in the shown in Fig. 8 to 11 the control unit 12 is provided. In other words, the separately such that 3 to 6 nozzles according to the comparative example is not a configuration that includes a flow controller such as the embodiment, the third through the sixth flow controller 12 according to the comparative example is separated from the body portion (10) It is provided. Then, the opening of the third to sixth comparative flow in accordance with the example the control unit 12 comprises a body portion 10, a discharge port with corresponding cost may be in the shape of a hollow, flow control portion 12 region in the opening of the body portion ( 10) of larger than the size of the discharge port. And, it is provided with a bottom and flow control portion 12 of the body portion 10 to be spaced apart.
[85]
Wherein the flow control unit 12 according to the third comparative example is a shape extending in the width direction or the horizontal direction.
[86]
And, fourth, and the flow control to the lower extending in the vertical direction of the fifth comparative example, the flow controller 12 is a third comparative flow control unit (hereinafter referred to as the first flow control section) extending in the lateral direction as shown in the example according to (a second flow control unit) may be a connected shape. In this case, the fourth flow controller 12 according to the comparative example is a shape in which the second flow controller to the part corresponding to the inside of an outer side bottom surface of the first flow control unit is installed. Then, the fifth comparative flow controller 12 according to the example is a shape in which the second flow control unit connected to the outside face of the outermost of the first flow control unit, the first hole is capable of passing the molten steel in the flow control unit 2 is provided. The hole is inclined upwardly outwardly of the flow control unit 12 may be a shape.
[87]
The flow control unit 16 according to the comparison example may be a shape having a convex curvature in an upward direction being inclined downward outwardly from the body portion (110).
[88]
The seventh and eighth comparison nozzle according to the example of turn and the dish comprises a body portion (10) for injecting the molten steel, the turn-dish separate flow to the discharge port below the within the body section 10 in shown in Figs. 12 and 13 the control unit 12 is provided. At this time, the seventh and the eighth flow controller 12 according to the comparative example is mounted on the tundish bottom surface state, the convex shape toward the discharge port. And the seventh, but the flow control unit 12 according to the comparative example is convex in the discharge port direction, and for example semi-circular having a curvature, the eighth comparison flow controller 12 according to the example is toward the discharge port direction, the smaller the diameter the outermost top the pointed shape, for example a triangle shape.
[89]
For the flow controller 12 according to the above-described third to eighth comparative examples, are provided so as to be separated or spaced apart without being connected to the body portion 10 as described above. And the third to eighth comparative flow control unit 12 comprises a body portion the main body or the thickness (F) and a flow control section of the wall to the width (D) of the passage 112 of the body portion 10 as in the embodiment according to Example ratio (X) of the sum (F + a) of width (a) of 120 is not configured to be a 74% or more and less than 125%.
[90]
[91]
The first bath surface flow velocity in the nozzle was measured using each of the first to eighth comparative examples and examples. For the experiment, when applied to each nozzle according to the first to eighth comparative examples and embodiments as described above to supply the molten steel in the tundish, and detects the flow rate of the bath surface around the nozzle. The time to open the 50% as in the first comparative example, had the discharge amount from the nozzle to 48kg / s, the time to open the 100% as in the second to eighth comparative examples and Examples, 100kg the discharge amount from the nozzle It was a / s. And the opening ratio on the basis of flow rate at 50% of the first comparative example, the second to sixth comparative examples and by calculating the ratio of the bath surface flow velocity at the nozzle application in accordance with an example, bath surface flow velocity index as shown in Table 1 the (I) was calculated.
[92]
In addition, we detect the tendency of the molten steel flow discharged from a nozzle, such as a thermal image data shown in each of Figs. 6 to 14.
[93]
TABLE 1
Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example No. 4 Comparative Example 5 Comparative Example 5 Example
Bath surface velocity index (I) 1 1.83 1.29 1.83 2.51 2.80 0.62

[94]
[95]
Referring to Table 1, the case of the third to eighth comparison are all bath surface flow velocity index (I) is greater than or equal to 1. That is, even if the installed flow control unit like the third to the eighth comparative example, the bath surface is greater than the flow rate of the first comparison example is not installed, the flow control member. Thus, the third to eighth comparison, when the nozzle and the flow control application according to the example in which the flow control can occur natang is larger than the eopneun first comparative example.
[96]
However, it can be seen that the flow control unit, such as the embodiment of the present invention when connected to a body portion, a bath surface flow velocity index (I) is a less than 0.62, the flow rate of the bath surface significantly decreased compared with the first comparative example. Accordingly, to supply the molten steel in the tundish by applying a nozzle having a flow control unit according to the embodiment, it looked at the effects of natang the bath surface around the nozzles to be reduced compared to the first comparative example of a conventional nozzle. Because of this, due to there natang slag can be suppressed or prevented as compared with the conventional to be incorporated into the molten steel, it is possible to suppress or prevent the occurrence of inclusions.
Industrial Applicability
[97]
According to the nozzle according to the embodiment of the present invention, it is possible to reduce the flow rate of the bath surface around the nozzle compared to prior art. Thus, when supplying the molten steel by applying a nozzle having a flow control unit according to the embodiment, natang in the bath surface around the nozzle is reduced in comparison with the prior art. Because of this, due to there natang slag can be suppressed or prevented as compared with the conventional to be incorporated into the molten steel, it is possible to suppress or prevent the occurrence of inclusions.

Claims

[Claim 1]A body portion is a discharge port which molten steel wherein molten steel discharged to the outside passing through the passage as possible and at the bottom provided; And a flow control unit mounted to the body portion to be formed extending to the center portion of the body into the body portion outer width direction; The nozzle comprising a.
[Claim 2]
The method according to claim 1, wherein the flow control unit includes a nozzle installed so as to be positioned on the outer side of the discharge port at the bottom of the body portion.
[Claim 3]
The method according to claim 1, wherein said flow control member extends in the lateral direction from the outside face of the body portion, wherein the flow control unit extends from the outer surface of the body portion length is greater in the thickness of the nozzle body wall.
[Claim 4]
The method according to claim 2, wherein the flow controller is a shape of the hollow area, the opening corresponding with the discharge port, the nozzle is installed such that the inner surface of the flow controller opening the peripheral wall contacts the outer peripheral surface of the body portion.
[Claim 5]
The method according to claim any one of claim 1 to claim 4, arrangement ratio ((A + F) of the width (A) of the body portion wall thickness (F) and the flow control of the width (D) of the body passage / D) * 100) are 74% or more and 125% or less nozzles.
[Claim 6]
The method according to claim 5, wherein the body portion (110) ratio of the width (A) of the flow control for the thickness (F) of the wall (A / F) of 2.1 or more and 4.2 or less nozzles.
[Claim 7]
The method according to claim 4, wherein the flow controller opening and the external shape is round, oval, any one of the nozzles of the polygon.
[Claim 8]
A method according to any one of claims 1 to 7, wherein the flow control unit includes a nozzle extending continuously along the circumferential direction of the body portion.
[Claim 9]
Claims 1 to 7 in which in the one wherein the bottom surface of the lower end of the body portion and the mutual position of the same nozzle bottom surface of the flow control member.