KR101700877B1 - Stopper for continuous casting - Google Patents

Abstract

The present invention provides a continuous casting stopper capable of uniformly controlling the supply amount of molten steel by effectively sealing the upper end of the nozzle even when the inclusion is fused to the inlet of the nozzle provided in the molten steel discharge port of the tundish or when the nozzle is deformed.
The stopper for continuous casting according to an embodiment of the present invention is a continuous casting stopper for controlling the flow rate of molten steel by opening and closing a nozzle for supplying molten steel from a first container located at an upper portion to a second container located at a lower portion, A center rod extending upward and downward toward an inlet of the nozzle, the center rod having an outer diameter larger than an inner diameter of the nozzle; A first cylinder for raising or lowering the center rod; A hollow rod having an inner diameter for receiving the center rod therein; And a second cylinder for raising or lowering the hollow rod, wherein a lower end of the center rod and the hollow rod closely adhered to the nozzle are formed to have an outer diameter decreasing toward the lower portion.

Description

[0001] STOPPER FOR CONTINUOUS CASTING [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stopper for continuous casting, and more particularly, to a stopper for continuous casting which is provided at an upper portion of a tundish to control the flow rate of molten steel supplied to a mold during continuous casting.

In general, the continuous casting process consists of a facility for producing molten steel produced in a steelmaking furnace, fed to a ladle by a tundish, and supplied to a mold to continuously produce a cast steel of a predetermined size. That is, in the continuous casting process, when the ladle containing refined molten steel is supplied to the tundish having the function of distributing to the respective strands while the ladle containing the refined molten steel is seated in the ladle turret, the molten steel is injected into the mold through the immersion nozzle to produce the cast .

At this time, a sliding gate nozzle system or a stopper system is used to control the flow rate of molten steel supplied to the mold.

The stopper moves upward and downward at the upper end of the molten steel discharge port, that is, at the upper end of the nozzle by the elevating unit to adjust the distance between the lower end of the stopper and the upper end of the nozzle to adjust the supply amount of molten steel supplied from the tundish to the mold .

On the other hand, in the steelmaking process, aluminum is used as a deoxidizer to reduce dissolved oxygen. Therefore, inclusions such as alumina oxides remain in the molten steel accommodated in the tundish. When the continuous casting process is performed, inclusions such as alumina oxide remaining in the molten steel melt-deposit at the molten steel discharge port, that is, the upper end entrance of the nozzle.

Thus, the distance between the lower end of the stopper and the upper end of the nozzle changes due to the alumina oxide melt-grown on the molten steel discharge port, that is, the upper end inlet of the nozzle, and the molten steel supplied from the tundish to the nozzle is made non- . Therefore, it is difficult to smoothly supply the molten steel to the mold, and the flow of the molten steel supplied to the mold through the nozzle is disturbed, thereby irregularly varying the level of the melt surface in the mold, There was a problem.

KR 10-0695907 B1 KR 10-2008-0037383 A

The present invention provides a continuous casting stopper capable of uniformly controlling the supply amount of molten steel by effectively sealing the upper end of the nozzle even when the inclusion is fused to the inlet of the nozzle provided in the molten steel discharge port of the tundish or when the nozzle is deformed.

A stopper for continuous casting according to an embodiment of the present invention is a stopper for continuous casting for controlling the flow rate of molten steel by opening and closing a nozzle for feeding molten steel from a first container located at the top to a second container located at the bottom, A center rod extending upward and downward toward an inlet of the nozzle, the center rod having an outer diameter larger than an inner diameter of the nozzle; A first cylinder for raising or lowering the center rod; A hollow rod having an inner diameter for receiving the center rod therein; And a second cylinder for raising or lowering the hollow rod, wherein a lower end of the center rod and the hollow rod closely adhered to the nozzle are formed to have an outer diameter decreasing toward the lower portion.

The lower end of the center rod and the lower end of the hollow rod may be formed as curved surfaces having different radii of curvature.

The lower end of the hollow rod may be formed as a curved surface having a larger radius of curvature than the lower end of the center rod.

A plurality of the hollow rods are provided so as to form different inner diameters, and each of the hollow rods is arranged outwardly from the inner side and can be individually raised or lowered.

The lower ends of the respective hollow rods may be formed as curved surfaces having different radii of curvature.

The lower end of each of the hollow rods may be formed as a curved surface having a radius of curvature larger than that of the lower end of the hollow rod in which the lower end of the hollow rod disposed on the inner side is disposed.

The lower ends of the hollow rods may be formed as flat surfaces having different slopes with respect to the horizontal direction.

The lower ends of the hollow rods may be formed in a plane having a larger slope with respect to the horizontal direction than the lower ends of the hollow rods disposed at the outer sides of the lower ends of the hollow rods disposed inside.

The first and second containers may also be tundishes and molds.

According to the stopper for continuous casting according to the embodiment of the present invention, the center rod and the hollow rod for accommodating the center rod are individually lifted or lowered to open or close the nozzle, whereby the inclusions are fused to the inlet of the nozzle, The upper end of the nozzle can be effectively sealed.

Further, it is possible to form the center rod and the lower ends of the hollow rods as curved surfaces having different radii of curvature, or to form a plane having different slopes, so that the supply amount of molten steel can be uniformly controlled, Quality can be improved.

In addition, it is possible to easily control the supply amount of molten steel by sealing the upper end of the nozzle without any work for removing the inclusions fused to the upper portion of the nozzle, thereby reducing the work load and improving the efficiency and productivity of the continuous casting process have.

1 is a schematic view showing a general continuous casting apparatus;
BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a stopper for continuous casting,
3 is a sectional view showing a stopper for continuous casting according to an embodiment of the present invention.
4 is a cross-sectional view showing a lower end of a stopper for continuous casting according to an embodiment of the present invention.
5 is a sectional view showing the lower end of the stopper for continuous casting according to the embodiment of the present invention.
6 is a view for explaining an operation of a continuous casting stopper according to an embodiment of the present invention.

The continuous casting stopper according to the present invention is characterized in that the inclusions are fused to the inlet of the nozzle provided at the molten steel discharge port of the tundish or the upper end of the nozzle is effectively sealed even when the nozzle is deformed to control the supply amount of molten steel uniformly .

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, Is provided to fully inform the user. Wherein like reference numerals refer to like elements throughout.

In general, the continuous casting machine is composed of a machine that is produced in a steelmaking furnace, receives molten steel transferred to a ladle from a tundish, and supplies the molten steel to a mold to continuously produce a cast steel of a predetermined size.

1 is a schematic view showing a general continuous casting apparatus. 1, a general continuous casting apparatus includes a tundish 1 containing molten steel 11, a mold 2 receiving molten steel 11 from the tundish 1, And a nozzle 3 provided between the molten steel discharge port 1a of the tundish 1 and the mold 2 to form a passage for supplying molten steel from the tundish 1 to the mold 2. [

In order to control the flow rate of the molten steel 11 supplied to the mold 2, the molten steel discharge port 1a, that is, the upper end of the nozzle 3, And a stopper (4) provided so as to be vertically movable up and down.

At this time, the stopper 4 is connected to the elevating unit 7 via the connecting member 7a so that the elevating unit 7 can move up and down within the tundish 1 by raising or lowering the elevating unit 7.

The stopper 4 moves up and down at the upper end of the molten steel discharge port 1a or the upper end of the nozzle 3 by the elevating unit 7 so that the lower edge of the stopper 4, And controls the supply amount of the molten steel (11) supplied to the mold (2) by adjusting the interval between the upper end openings of the nozzle (3).

When the molten steel 11 is supplied to the mold 2, the level sensor 5a detects the position of the bath surface of the mold 2. The level controller 5b connected to the level sensor 5a detects the position of the melt surface of the actuator 6 ) Of the molten steel (11) supplied to the mold (2) through the elevation control of the stopper (4) by raising and lowering the elevation unit (7) according to the detected position of the bath surface of the mold .

On the other hand, by using aluminum as a deoxidizing agent for reducing dissolved oxygen in the steelmaking process, inclusions such as alumina oxides remain in the molten steel 11 contained in the tundish 1, and thus the continuous casting process The lower end of the stopper 4 or the upper inlet of the molten steel discharge port 1a or the nozzle 3 is provided with an inclusion 11a such as alumina oxide remaining in the molten steel 11, ) Is fusion-grown.

Therefore, inclusions 11a such as alumina oxide welded to the lower end of the stopper 4 or the upper inlet of the molten steel discharge port 1a, that is, the nozzle 3, are formed between the lower end of the stopper 4 and the lower end of the nozzle 3 So that the flow of the molten steel 11 supplied from the tundish 1 to the nozzle 3 is unevenly changed so that the molten steel 11 is supplied to the mold 2, And the flow of the molten steel 11 supplied to the mold 2 through the nozzle 3 is disturbed to irregularly vary the level of the melt surface in the mold 2. As a result, And the productivity is lowered.

3 is a cross-sectional view showing a stopper for continuous casting according to an embodiment of the present invention. 3, the continuous casting stopper according to an embodiment of the present invention controls the flow rate of molten steel by opening and closing a nozzle 30 for supplying molten steel from a first container located at an upper position to a second container located at a lower position, A center rod (100) extending vertically toward an inlet of the nozzle (30) and having an outer diameter larger than an inner diameter of the nozzle (30); A first cylinder 200 for raising or lowering the center rod 100; A hollow rod 300 having an inner diameter for receiving the center rod 100 therein; And a second cylinder 400 for raising or lowering the hollow rod 300. The lower end of the center rod 100 and the hollow rod 300 which are in close contact with the nozzle 30 have a smaller outer diameter .

The first and second containers correspond to the tundish 10 and the mold (not shown), respectively, and the nozzle is connected to a nozzle 30 (not shown) provided in the molten steel discharge port of the tundish 10 However, the container and the nozzle are not limited thereto, but may be applied to any kinds of containers and nozzles for controlling the flow rate of molten steel accommodated in the first container and supplying the same to the second container.

The center rod 100 is located at an upper portion of the nozzle 30 provided at the molten steel discharge port of the tundish 10 and is drawn into the tundish 10 from the top of the tundish 10 to open and close the nozzle 30 So as to have an outer diameter larger than the inner diameter of the nozzle 30.

In general, the nozzle 30 provided in the molten steel discharge port of the tundish 10 has a shape in which the edge is curved and the entrance area of the nozzle 30 decreases from the upper portion to the lower portion. The lower end of the center rod 100 is formed to have a reduced outer diameter as it goes downward.

The center rod 100 is connected to the first cylinder 200 and moves up or down. When the first cylinder 200 is lifted or lowered, the center rod 100 slides within the hollow rod 300, (Not shown).

The hollow rod 300 has a substantially cylindrical shape in which an inner diameter for accommodating the center rod 100 is formed. The lower end of the hollow rod 300 is also formed so as to be in close contact with the nozzle 30 so that the outer diameter decreases toward the lower part in order to control the flow of molten steel into the mold.

The hollow rod 300 is connected to the second cylinder and is raised or lowered independently of the center rod 100. When the center rod 100 is not completely brought into close contact with the upper end of the nozzle 30 due to the inclusion of the inclusion in the upper end inlet of the nozzle 30 or the deformation of the nozzle 30, (100) so as to seal the upper end of the nozzle (30). That is, when the upper end of the nozzle 30 can not be closed by the center rod 100, the hollow rod 300 is lowered more than the center rod 100 and the upper end of the nozzle 30 is efficiently The supply amount of the molten steel can be uniformly controlled even when the inclusions are fused to the upper end inlet of the nozzle 30 or when the nozzle 30 is deformed.

A plurality of the hollow rods 300 and 350 are provided so as to form different inner diameters, and the hollow rods 300 and 350 are disposed outwardly from the inner side and are individually raised or lowered to form the hollow rods 300 and 350 Protruded from the lower end or drawn in.

In Fig. 3, two hollow rods are shown as an example. 3, the inner hollow rod 300 has an inner diameter for receiving the center rod 100 therein, and the hollow rod 350 located on the outer side has a hollow rod 300 located on the inner side. And is lifted or lowered individually by the plurality of second cylinders 400 and 450, respectively.

A plurality of hollow rods 300 and 350 are arranged outwardly from the inside and each of the hollow rods 300 and 350 is individually raised or lowered so that not only the center rod 100 but also the inner hollow rod 300, The upper end of the nozzle 30 can be more effectively sealed by the hollow rod 350 on the outer side when the upper end of the nozzle 30 can not be completely closed by the hollow shaft 300. [

4 is a sectional view showing the lower end of the stopper for continuous casting according to the embodiment of the present invention. 4, a continuous casting stopper according to an embodiment of the present invention includes a center rod 100 and a hollow rod 300, which receives the center rod 100, The lower end of the rod 100 and the lower end of the hollow rod 300 may be formed to have different radii of curvature. In addition, the lower end of the hollow rod 300 may be formed as a curved surface having a larger radius of curvature than the lower end of the center rod 100.

The lower ends of the center rod 100 and the hollow rod 300 are formed in a hemispherical shape having a curved surface so as to prevent breakage due to contact with the nozzle 30 and to be in intimate contact with the nozzle 30 effectively. In this case, the lower end of the center rod 100 and the hollow rod 300 may be formed with the same curved surface, but the inclination may be fused to the upper end inlet of the nozzle 30 or the nozzle 30 may be deformed, The end of the hollow rod 300 comes into contact with the upper end of the nozzle 30 to be damaged when the hollow rod 300 is lowered secondarily due to the fact that the hollow rod 300 is not completely brought into close contact with the upper end of the nozzle 30 So that the curvature radius D2 of the lower end of the hollow rod 300 is greater than the radius of curvature D1 of the lower end of the center rod 100 in order to seal the upper end of the nozzle 30 more effectively. It can be formed into a curved surface.

Even when a plurality of hollow rods 300 and 350 are arranged so as to be arranged outward from the inside, the radius of curvature D3 at the lower end of the hollow rod 350 at the outer side is set to the radius of curvature D2) so that the same effect can be obtained.

5 is a cross-sectional view showing the lower end of a stopper for continuous casting according to another embodiment of the present invention. 5, when the continuous casting stopper according to another embodiment of the present invention includes a plurality of hollow rods 300 and 350 arranged outwardly from the inside, the lower ends of the hollow rods 300 and 350 are horizontally It is possible to form a plane having different slopes with respect to the direction of the substrate. Preferably, the lower end of each of the hollow rods 300 and 350 is a flat surface having a larger inclination with respect to the horizontal direction than the lower end of the hollow rod 350 disposed at the lower side of the hollow rod 300 disposed at the inner side, As shown in FIG.

As described above, the lower end of the center rod 100 may be formed in a hemispherical shape having a curved surface so as to prevent breakage due to contact with the nozzle 30 and to be in close contact with the nozzle 30 effectively. However, when the hollow rods 300 and 350 are formed in a plurality of hollow rods 300 and 350 so as to be arranged outwardly from the inside, the hollow rods 300 and 350 may be formed in a plane having a constant inclination. The inclination? 1 with respect to the horizontal direction of the lower end is formed into a plane having different inclination from each other so as to have a larger value than the inclination? 2 with respect to the horizontal direction of the lower end of the hollow rod 350 disposed outside, When the upper end of the nozzle 30 can not be completely closed by the inner hollow rod 300 as well as the inner hollow rod 300, the upper end of the nozzle 30 can be further closed by the hollow rod 350 on the outer side.

Hereinafter, a mode in which the continuous casting stopper having the above-described construction closely contacts the upper end of the nozzle to control the supply of molten steel will be described in detail.

6 is a view for explaining an operation of a continuous casting stopper according to an embodiment of the present invention. 6 (a) is a view showing a state in which a nozzle is opened by a continuous casting stopper according to an embodiment of the present invention, and Fig. 6 (b) is a cross- Fig. 7 is a view showing a state in which the nozzle is closed by the stopper. Fig.

The center rod 100 and the hollow rod 300 are both raised by the first cylinder 200 and the second cylinder 400 when increasing the supply amount of molten steel supplied to the mold in the tundish 10 during the continuous casting . Further, even when a plurality of hollow rods 300, 350 are arranged so as to be arranged outward from the inside, the hollow rods 300, 350 are lifted by the plurality of second cylinders 400, 450, respectively.

On the contrary, when the molten steel is blocked from being supplied to the mold through the nozzle 30 in the tundish 10, the center rod 100 descends by the first cylinder 200. At this time, if the inclination is fused to the upper end entrance of the nozzle 30 or the nozzle 30 is deformed and the center rod 100 is not lowered to a position where it completely comes into close contact with the upper end of the nozzle 30, Is completely lowered by the second cylinder 400 to a position where it is completely in contact with the upper end of the nozzle 30, thereby sealing the upper end of the nozzle 30.

The plurality of hollow rods 300 and 350 may be arranged so as to be disposed outwardly from the inner side so that not only the center rod 100 but also the inner hollow rod 300 is lowered to a position where the inner hollow rod 300 is completely brought into close contact with the upper end of the nozzle 30 The outer hollow rod 350 may be lowered to a position where it is completely in contact with the upper end of the nozzle 30 to seal the upper end opening of the nozzle 30.

The center rod 100 and the lower ends of the hollow rods 300 and 350 may be formed in a hemispherical shape having a curved surface so as to be effectively brought into close contact with the nozzle 30. The hollow rod 300 And the end of the hollow rod 300 on the inner side or the hollow rod 350 on the outer side is in contact with the upper end of the nozzle 30 and is damaged And it is possible to seal the upper end of the nozzle 30 more effectively.

The lower end of each of the hollow rods 300 and 350 is connected to the lower end of the hollow rod 350 disposed at the outer side with respect to the horizontal direction of the lower end of the hollow rod 300, It may be formed as a plane having different slopes so as to have a value larger than the inclination [theta] 2 as described above.

The center rod 100 is first lowered by the first cylinder 200 and the center rod 100 is moved to the upper end of the nozzle 30 in accordance with the operation of the stopper for continuous casting according to the embodiment of the present invention The hollow rod 300 is independently lowered by the second cylinder 400 when the hollow rod 300 is not lowered to the fully closed position. However, when the center rod 100 and the hollow rod 300 are raised or lowered The center rod 100 and the hollow rod 300 are simultaneously lowered and moved down to a position where the center rod 100 and the hollow rod 300 are completely in contact with the upper end of the nozzle 30, The central rod 100 and the hollow rod 300 are lifted or lowered individually from the tundish 10 to the mold 30 by further lowering the hollow rod 300 to close the upper inlet of the nozzle 30. [ Supplied dragon In the operation of the various methods of controlling the supply amount can be applied as a matter of course.

While the preferred embodiments of the present invention have been described and illustrated above using specific terms, such terms are used only for the purpose of clarifying the invention, and the embodiments of the present invention and the described terminology are intended to be illustrative, It will be obvious that various changes and modifications can be made without departing from the spirit and scope of the invention. Such modified embodiments should not be individually understood from the spirit and scope of the present invention, but should be regarded as being within the scope of the claims of the present invention.

10: tundish 30: nozzle
100: center rod 200: first cylinder
300, 350: hollow rod 400, 450: second cylinder

Claims (9)

1. A continuous casting stopper for controlling a flow rate of molten steel by opening and closing a nozzle for supplying molten steel from a first container located at an upper portion to a second container located at a lower portion,
A center rod extending upward and downward toward an inlet of the nozzle and having an outer diameter larger than an inner diameter of the nozzle and having a curved surface having a radius of curvature at a lower end which is in close contact with the nozzle,
A first cylinder for raising or lowering the center rod;
And a lower end of the hollow rod which is in close contact with the nozzle is formed into a curved surface having a radius of curvature different from a radius of curvature of the lower end of the center rod to secondarily open and close the nozzle; And
And a second cylinder for raising or lowering the hollow rod,
And a lower end of the center rod and the hollow rod closely adhered to the nozzle are formed to have a reduced outer diameter as the lower portion is lowered.
delete The method according to claim 1,
And the lower end of the hollow rod is formed as a curved surface having a larger radius of curvature than the lower end of the center rod.
The method according to claim 1,
A plurality of hollow rods are provided so as to form different inner diameters,
Each of the hollow rods is disposed outwardly from the inside and is individually lifted or lowered.
The method of claim 4,
Wherein the lower end of each of the hollow rods is formed as a curved surface having a different radius of curvature.
The method of claim 4,
Wherein a lower end of each of the hollow rods is formed as a curved surface having a radius of curvature larger than that of a lower end of the hollow rod in which a lower end of the hollow rod disposed on the inner side is disposed.
delete delete The method according to claim 1,
The first container and the second container are a tundish and a stopper for continuous casting which is a mold.

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