KR20140060934A - Apparatus for controlling melten metal flow and the method thereof - Google Patents

Abstract

The present invention relates to a molten metal flow control apparatus and a method for controlling the same comprising: a first container for forming inner space for containing molten metal, and having a discharge hole for discharging the molten metal into a second container; a first plate installed away from the floor inside the first container, and vertically extended and formed; a second plate arranged away from the first plate in the flow direction of the molten metal, and in contact with the floor inside the first container; a curved part for forming a path through which the molten metal is passing in a part of the floor inside the first container and the lower part of the second plate; and a blocking member arranged inside the curved part to open or close the path. Therefore, the residence time of the molten metal inside the first container is increased, so the floatation time of inclusions inside the molten metal can be secured. Accordingly, the quality of the steel can be increased by inhibiting the inclusions from being included in the steel, which is finally produced.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molten metal flow control apparatus,

The present invention relates to a molten metal flow control apparatus and a control method thereof, and more particularly, to a molten metal flow control apparatus capable of increasing the residence time of molten metal in a container to increase the separation rate of inclusions contained in the molten metal, .

Generally, a continuous casting machine (hereafter referred to as a continuous casting machine) is a machine in which a molten steel produced in a steelmaking furnace is accommodated in a ladle, a certain amount is supplied to a tundish, molten steel accommodated in the tundish is supplied to a mold It is a continuous production line with a constant size of cast steel. Continuous casting (continuous casting) is a continuous casting process in which semi-solidified cast products are continuously drawn into the lower side of the casting mold to produce semi-finished products having various shapes such as slab, bloom, billet, process.

The tundish is formed in a hollow container shape capable of receiving molten steel therein, and is provided with a discharge hole formed through the bottom of the tundish to discharge molten steel. The tundish accommodates a certain amount of molten steel, stays the molten steel for a predetermined time, controls the casting speed, and distributes the molten steel to be supplied into the mold. If the molten steel does not have sufficient residence time in the tundish, inclusions that have not been separated from the molten steel flow into the mold together with the molten steel to cause defects in the cast steel.

In order to secure the residence time of the molten steel in the tundish, conventionally, as shown in Fig. 1, a weir which induces the flow of molten steel injected through the shroud nozzle 5 in the ladle to the inner bottom of the tundish 1 And a dam 30 formed after the weir 10 in the moving direction of the molten steel to induce an upward flow of the molten steel led to the inner bottom so as to change the flow of the molten steel variously A method was employed in which molten steel supplied into the tundish was prevented from being directly injected into the mold.

However, this method is performed by the dam hole 35 provided for the purpose of reducing the debris in the dam 30 provided for upward flow of molten steel, as soon as molten steel is discharged from the shroud nozzle 5, There is a problem that a part of the molten steel is bypassed through the dam hole 35 to shorten the residence time of the molten steel.

Such a problem is that the inclusion contained in the molten steel can not be lifted and separated, and the inclusion causes defects in the cast steel.

KR 0598574 B KR 2005-0005067 A1

The present invention provides a molten metal flow control apparatus capable of increasing the residence time of molten metal in a vessel and a control method therefor.

The present invention provides a molten metal flow control apparatus and a control method thereof that can improve the cleanliness of a molten metal by increasing the floating rate of inclusions in the molten metal.

The present invention provides a molten metal flow control apparatus and a control method thereof that do not require power means.

The apparatus for controlling the flow of molten metal according to the embodiment of the present invention includes a first container having an inner space in which a molten metal is received and a discharge hole for discharging the molten metal to the second container, A second plate disposed to be spaced apart from the first plate in the flow direction of the molten metal and in contact with the first container inner bottom surface, A bent portion forming at least a part of the bottom surface of the first container inner wall and forming a passage through the molten metal and

And a blocking member disposed inside the bent portion and opening and closing the passage.

The bent portion may include an injection port into which the molten metal is injected, an exhaust port formed in opposition to the injection port, and an inner space through which the molten metal passes.

The blocking member may have an apparent specific gravity of 3 to 4.

The diameter of the discharge port is smaller than the diameter of the injection port, and the blocking member can open and close the discharge port.

The diameter of the injection port may be about 1.2 to 1.5 times the diameter of the blocking member.

The diameter of the outlet may be about 0.7 to 0.8 times the diameter of the blocking member.

The diameter of the point where the width of the inner space is largest may be about 1.8 to 2.0 times the diameter of the blocking member.

The first container may be a tundish and the second container may be a mold.

A method for controlling a flow of molten metal according to an embodiment of the present invention includes the steps of providing a first container having a molten metal therein and having a path through which the molten metal passes and which is opened and closed by movement of a blocking member; Closing the path by the movement of the molten metal, discharging the molten metal from the first container to the second container connected to the first container, And floating the member on the molten metal to open the path.

The process of discharging the molten metal is injected at a front upper portion of a second plate provided in the first container and discharged through a discharge hole provided at a rear lower portion of the second plate,

The molten metal may be moved over the upper portion of the second plate.

The process of opening the path may be performed when an amount of the molten metal in the first container that can not pass over the upper portion of the second plate remains.

According to the embodiment of the present invention, it is possible to increase the residence time of the molten metal on the container in which the molten metal including molten iron and molten steel is accommodated, thereby increasing the separation and floating rate of inclusions in the molten metal.

For example, when the molten steel is accommodated in the tundish of the continuous casting facility, it is possible to increase the residence time until the molten steel is supplied to the mold by the blocking member disposed inside the bent portion of the dam. That is, it is possible to suppress the bypass phenomenon that the molten steel passes directly to the mold by blocking the outlet of the bent portion of the blocking member.

As described above, the residence time of the molten steel is increased, and a sufficient time is secured to allow the inclusions contained in the molten steel to separate, so that the inclusions can be prevented from flowing into the mold. Thus, the quality of the finally produced steel can be increased.

Further, the blocking member closes the discharge port by the hydraulic pressure of the molten steel contained in the container, so that the molten steel passes over the upper portion of the second plate, and as the pressure applied by the molten steel in the container decreases (that is, Since the blocking member opens the outlet, it is possible to reduce the residue remaining in the container.

And controlling the flow of the molten steel, the molten steel pushes the blocking member to apply pressure, and the blocking member blocks the flow of molten steel by blocking the outlet by the pressure. Therefore, a separate power means for controlling the flow of molten steel is not required.

1 is a view showing a flow of a conventional molten metal flow control device and a molten metal.
2 is a perspective view showing a molten metal flow control apparatus according to an embodiment of the present invention.
FIG. 3 is an enlarged view of FIG. 2 A. FIG.
4 is a view for explaining a bent portion and a blocking member according to an embodiment of the present invention.
5 is a flowchart illustrating a method of controlling the flow of molten metal using the apparatus for controlling the flow of molten metal according to an embodiment of the present invention.
6 is a view showing the flow of molten steel according to the operating state of the molten metal flow control apparatus according to the embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It will be apparent to those skilled in the art that the present invention may be embodied in many 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, It is provided to let you know. Wherein like reference numerals refer to like elements throughout.

The molten metal flow control device is a device capable of increasing the residence time of the molten metal before the molten metal is supplied from the first container to the second container. Thus, in the present invention, the continuous casting equipment to which the melt flow control device is applied will be described. At this time, a tundish is used as the first container and a mold that receives molten steel from the tundish as the second container will be described as an example. However, the present invention is not limited thereto, and the present invention is applicable to various equipments and containers which can increase the residence time of the molten metal by controlling the flow of the molten metal in the space where the molten metal such as molten iron and molten steel is accommodated.

2 is a perspective view showing a molten metal flow control apparatus according to an embodiment of the present invention. FIG. 3 is an enlarged view of FIG. 2 A. FIG. 4 is a view for explaining a bent portion and a blocking member according to an embodiment of the present invention. FIG. 4A is a perspective view of a bending portion and a blocking member according to an embodiment of the present invention, and FIG. 4B is a view for explaining the diameter relationship of the bending portion and the blocking member according to the embodiment of the present invention.

The molten metal flow control apparatus 100 includes a tundish 200 for forming an internal space in which molten steel is received, a first plate 220 spaced apart from an inner bottom surface of the tundish 200 and extending in the vertical direction, A second plate 240 spaced apart from the first plate 220 in the flow direction of the molten steel and contacting the inner bottom surface of the tundish 200 and a lower portion of the tundish 200, A bending part 300 forming a passage through which the molten steel passes and at least a blocking member 400 disposed inside the bending part 300 for opening and closing the passage through which the molten steel passes.

The tundish 200 is formed in a hollow container shape in which molten steel is received therein. A drain hole 260 through which the molten steel is discharged is formed on one bottom surface of the tundish 200 through the bottom surface of the tundish 200. The tundish 200 has a first plate 220, The plates 240 are spaced apart from each other toward the direction of flow of molten steel. In this case, the tundish 200 is generally formed in a symmetrical shape with respect to the shroud nozzle 5 connected to the lower portion of the ladle (not shown). In the following drawings, only one side of the tundish 200 is illustrated, The components will be described below.

The first plate 220 is disposed inside the tundish 200 to guide the flow of molten steel discharged from the shroud nozzle 5 to the lower portion of the tundish 200. The first plate 220 is coupled to the inner upper surface of the tundish 200 and the upper and lower surfaces of the tundish 200 at a predetermined height from the inner bottom surface of the tundish 200. That is, it is coupled to the side surface of the tundish 200 in a direction intersecting the flowing direction of the molten steel with reference to the flowing direction of the molten steel. At this time, the height of the first plate 220 spaced from the bottom of the tundish 200 is not limited, but it is desirable to have a height that can reduce the initial flow of molten steel so as to increase the residence time of the molten steel.

The second plate 240 is formed to be spaced apart from the first plate 220 by a predetermined distance in the flow direction of the molten steel to guide the upward flow to the molten steel led to the inner bottom by the first plate 220. Accordingly, the tundish 200 is extended and installed at an inner bottom surface of the tundish 200 and a predetermined height above the tundish 200 at the front and rear of the tundish 200.

At this time, the height of the second plate 240 is not limited as long as the first plate 220 is extended upward. However, if the height of the second plate 240 is too high, the upward flow of the molten steel is not easy, and if the height is too low, the flow velocity of the molten steel increases more than necessary, And the minimum residence time of the molten steel necessary for the inclusion separating portion in the molten steel is not decreased due to the increase in the molten steel flow rate. The second plate 240 is preferably formed to have a predetermined thickness so as to form a bent portion 300 described later.

The bent portion 300 forms a passage through the molten steel to at least a part of the inner bottom surface of the tundish 200 and the lower portion of the second plate 240, An inlet 310 through which molten steel is injected and an outlet 350 disposed at a position opposite to the injection port 310 form an internal space 330 through which the molten steel passes. At this time, the bent portion 300 is preferably formed at a ratio of 8 to 2 on the tundish 200 and the second plate 240. This is because the thickness of the bottom of the tundish 200 is limited so that the thickness of the bottom surface of the tundish 200 having the bent portion 300 increases as the ratio of forming the bent portion 300 to the bottom surface of the tundish increases It is because it becomes thin.

The injection port 310 forms an inlet through which molten steel is injected to be accommodated in the bent portion 300 when the molten steel accommodated in the tundish 200 is guided to the lower portion of the first plate 220 and flows. At this time, the diameter of the injection port 310 will be described in detail below.

The discharge port 350 is a passage through which the molten steel injected from the injection port 310 is discharged, and may be formed at a position opposite to the injection port 310.

More specifically, as shown in FIGS. 3 and 4, the discharge port 350 is formed in the shape of a pot having a diameter smaller than that of the injection port 310. In the present invention, the bending portion 300 is formed in a jar shape so that the inner space 330 has a bending shape. However, the shape of the bending portion 300 is not limited to this and may be various shapes . At this time, the bending part 300, which will be described later, may be formed with a degree of curvature and height such that the blocking member 400 does not deviate from the discharge port 350.

The bent part 300 of the present invention forms a curved surface at least at a lower part of the lower part of the second plate 240 and is formed at a predetermined depth in the inner bottom surface of the tundish 200 so that the curved surfaces form the bent part 300 However, the method of forming the bent portion 300 is not limited to this, and the bent portion 300 may be formed by mounting the bent model on the tundish.

The blocking member 400 is formed in the shape of a ball or the like and disposed in the inner space of the bending part 300 to open and close the discharge port 350 of the bending part 300. At this time, it is preferable that the barrier member 400 is made of a material having high heat resistance (for example, ceramic) capable of withstanding high temperatures.

The blocking member 400 closes the discharge port 350 by the pressure of the molten steel at the initial stage when the molten steel is received in the tundish 200. When the amount of the molten steel is reduced, It is preferable to have a specific gravity that can float on the molten steel. Accordingly, the apparent specific gravity of the blocking member 400 is limited to 3 to 4 in the present invention. At this time, when the apparent specific gravity of the blocking member 400 is lower than 3, the impact received by the flow of molten steel increases, so that the movement of the blocking member 400 on the molten steel is not stable. In addition, when the apparent specific gravity of the blocking member 400 is 4 or more, the blocking member 400 may not float on the molten steel due to a high specific gravity and sink into the molten steel. Therefore, Range is preferred.

The bending part 300 and the blocking member 400 formed as described above will be described in detail.

Referring to FIG. 4, the blocking member 400 is disposed with a diameter B in the interior space 330 of the bend 300. The blocking member 400 is smaller than the injection port 310 of the bending part 300 and is larger than the discharge port 350 so that the blocking member 400 can not escape from the discharge port 350. The diameter F of the injection port 310 of the bending part 300, the diameter D of the discharge port 350 and the diameter E of the widest point in the internal space 330 of the bending part 300 are respectively And has a diameter of 1.2 to 1.5 times, 0.7 to 0.8 times, and 1.8 to 2.0 times the diameter B, respectively.

On the other hand, when the diameter F of the injection port 310 is 1.2 times or less the diameter B of the blocking member 400, molten steel is injected to push out the blocking member 400 to close the discharge port 350 The diameter is preferably 1.2 times or less because molten steel which can not be applied with sufficient pressure is injected. When the diameter of the injection port 310 is 1.5 times or more the diameter of the blocking member 400, the amount of molten steel injected into the bending part 300 through the injection port 310 instantaneously increases, The diameter of the injection port 310 is preferably 1.2 to 1.5 times the diameter of the blocking member 400 because the pressure applied to the blocking member 400 is increased.

When the diameter D of the discharge port 350 is equal to or less than 0.7 times the diameter B of the blocking member 400, when the blocking member 400 opens the discharge port 350, The amount of molten steel to be supplied is reduced and the amount of molten steel supplied to the mold is also reduced. This is because the quality of the cast steel can be reduced in a continuous casting process for producing cast steel having a certain thickness and size. When the diameter of the discharge port 350 is 0.8 times or more the diameter of the blocking member 400, since the blocking member 400 may exit the discharge port 350 by the pressure of the molten steel, the diameter of the discharge port 350 The range is preferably 0.7 to 0.8 times the diameter of the blocking member 400.

Finally, when the diameter E of the widest point in the inner space 330 is 1.8 times or less the diameter B of the blocking member 400, the blocking member 400 opens the outlet 350, There is not formed a space that can be floated on the surface of the substrate. If the diameter of the largest point in the inner space 330 is 2.0 or more in diameter of the blocking member 400, the amount of molten steel accommodated in the inner space 330 increases, The diameter of the central portion is preferably 1.8 to 2.0 times the diameter of the blocking member 400 because the time for the blocking member 400 to float on the molten steel is delayed and the outlet 350 is not easy to open.

Hereinafter, the flow of molten steel in the tundish by the molten metal flow control apparatus according to the embodiment of the present invention will be described in detail with reference to FIGS. 5 and 6. FIG.

5 is a flowchart illustrating a method of controlling the flow of molten metal using the apparatus for controlling the flow of molten metal according to an embodiment of the present invention. 6 is a view showing a flow of molten steel according to a molten metal flow control apparatus according to an embodiment of the present invention. 6 (a), 6 (b) and 6 (c) show the flow of molten steel sequentially.

A method of controlling a flow of molten metal according to an embodiment of the present invention includes the steps of: providing a first container having a molten metal therein and having a path through which the molten metal passes and which is opened and closed by movement of the blocking member; A process of closing the path by the movement of the molten metal, a process of discharging the molten metal from the first container to the second container connected to the first container, and a step of suspending the shutoff member in the molten state, It is done through the process of opening.

First, molten steel supplied from the ladle to the tundish 200 is accommodated in the tundish via the shroud nozzle 5 connected to the lower portion of the ladle (S10). 6 (a), the molten steel supplied through the shroud nozzle 5 flows into the tundish 200 through the first plate 220 installed on the tundish 200 and the inner bottom surface of the tundish 200 And flows through the spacing space.

At this time, molten steel is injected into the inner space 330 of the bent portion 300 between the second plate 240 and the tundish 200. However, due to the hydraulic pressure of the molten steel, the blocking member 400 disposed inside the bending portion 300 closes the discharge port 350 through which the molten steel is discharged from the bending portion 300 (S20). Accordingly, the molten steel accommodated in the inner space 330 of the bending portion 300 can not move in the mold direction, and therefore, the molten steel stays in the bending portion 300. Molten steel accommodated in the tundish 200 in addition to the molten steel remaining in the inner space 330 of the bent portion 300 flows over the upper portion of the second plate 240 and flows into the mold (S30).

Accordingly, since the molten steel discharged through the bending portion 300 is not present at the beginning, it is possible to prevent the minimum residence time of the molten steel from being reduced due to the bypass of molten steel.

Next, after the supply of molten steel in the ladle is completed, when the molten steel stored in the tundish 200 is supplied to the mold and the amount of molten steel in the tundish 200 is less than the initial amount, The outlet 350 of the bent portion 300 is opened (S40), as shown in (b) of FIG. That is, when molten steel is present in the tundish 200 so that the pressure applied by the molten steel to the blocking member 400 can not form the required pressure to close the outlet 350 of the bend 300 The discharge port 350 of the bent portion is opened. At this time, the blocking member 400 has a load floating on the molten steel, so that the process does not sink into the molten steel.

Finally, when almost all of the molten steel stored in the tundish 200 is supplied to the mold, the molten steel contained in the tundish 200 is lowered as shown in FIG. 6 (c) Almost all of them are supplied to the mold (S50), and the process inside the tundish 200 is completed.

As described above, according to the embodiment of the present invention, it is possible to increase the time for the molten steel to stay in the tundish until the molten steel accommodated in the tundish is supplied to the mold. That is, the dam member formed inside the tundish, the bent portion formed with a curved line in a part of the bottom portion of the tundish, and the blocking member disposed in the bent portion block the outlet of the bent portion so that the initial molten steel is not bypassed through the dam hole The molten steel can be prevented from being supplied to the mold with a short residence time by the dam hole in the related art.

By thus increasing the residence time until the molten steel is supplied to the mold, it is possible to secure a time for separating the inclusions, which are essentially contained in the molten steel, before the molten steel is separated into slag, thereby suppressing defects in the steel containing the inclusions can do.

Further, in the case where a hole is not formed in the dam to secure separation of the inclusion from the prior art, it is possible to suppress the increase of the residue in the tundish.

The shielding member for opening and closing the discharge port of the bent portion is a method for closing the discharge port by the force of the molten steel pushing the shielding member and floating the shielding member to the molten steel to open the discharge port when a small amount remains in the tundish, There is no need for a separate power means for opening and closing the bent portion in the case.

Although the present invention has been described with reference to the accompanying drawings and the preferred embodiments described above, the present invention is not limited thereto but is limited by the following claims. Accordingly, those skilled in the art will appreciate that various modifications and changes may be made thereto without departing from the spirit of the following claims.

100: Melting flow control device
200: tundish 220: first plate
240: second plate 300: bent portion
310: Inlet port 330: Inner space
350: exhaust port 400: blocking member

Claims (11)

A first container defining an inner space in which the molten metal is accommodated and having a discharge hole for discharging the molten metal into the second container;
A first plate spaced apart from an inner bottom surface of the first container and extending in the vertical direction;
A second plate spaced apart from the first plate in the flow direction of the molten metal, the second plate being in contact with the first container inner bottom; And
A bent portion forming a passage through the molten metal at a lower portion of the second plate and at least a part of the bottom surface of the first container; And
And a blocking member disposed inside the bent portion, the blocking member opening and closing the passage. The method according to claim 1,
The bend portion
An injection port into which the molten metal is injected;
A discharge port formed opposite to the injection port; And
And an inner space through which the molten metal flows. The method according to claim 1,
Wherein the blocking member has an apparent specific gravity of 3 to 4. The method of claim 2,
Wherein the diameter of the outlet is smaller than the diameter of the inlet,
And the blocking member opens and closes the outlet. The method of claim 4,
The diameter of the injection port,
Wherein the flow rate of the molten metal is about 1.2 to 1.5 times the diameter of the blocking member. The method of claim 4,
The diameter of the outlet
Wherein the flow rate of the molten metal is about 0.7 to 0.8 times the diameter of the blocking member. The method according to claim 5 or 6,
The diameter of the point at which the width of the inner space is largest,
Wherein the flow rate of the molten metal is about 1.8 to 2.0 times the diameter of the blocking member. The method according to claim 1,
Wherein the first container is a tundish and the second container is a mold. Providing a first container having a molten metal therein and a path through which the molten metal flows and which is opened and closed by movement of the shutoff member;
A process in which the molten metal flows into the first vessel;
Closing the path by the movement of the molten metal;
Discharging the molten metal from the first container to a second container connected to the first container; And
And floating the blocking member over the molten metal to open the path. The method of claim 9,
In the process of discharging the molten metal,
The second plate is injected at the front upper portion of the second plate provided in the first container and discharged to the second container through the discharge hole provided at the rear lower portion of the second plate,
Wherein the molten metal is moved over an upper portion of the second plate. The method of claim 9,
The process of opening the path includes:
Wherein the amount of the molten metal remaining in the first container is such that an amount of the molten metal remaining in the first container can not exceed the upper portion of the second plate.

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