KR20120033102A

KR20120033102A - Apparatus for removing inclusions of molten steel in tundish

Info

Publication number: KR20120033102A
Application number: KR1020100094701A
Authority: KR
Inventors: 기웅간; 서상원
Original assignee: 현대제철 주식회사
Priority date: 2010-09-29
Filing date: 2010-09-29
Publication date: 2012-04-06
Also published as: KR101225228B1

Abstract

The present invention relates to a molten steel inclusion removal device of the tundish, the cylindrical slit (3a) is formed on the stopper 3, the porous refractory (3b) is provided on the outer side of the slit (3a), the slit (3a) Argon gas is supplied.
Therefore, argon gas is injected into the molten steel, and nonmetallic inclusions in the molten steel are lifted by the argon gas bubbles, and are then collected and removed in the slag.

Description

Apparatus for removing inclusions of molten steel in tundish}

The present invention relates to a molten steel inclusion removal device of a tundish, and more particularly, to a molten steel inclusion removal device of a tundish, which is capable of preventing clogging of an immersion nozzle by reducing the inclusions of molten steel in the tundish and reducing defects of cast steel. will be.

In the steel mill, molten steel produced through the steelmaking process is continuously cast using the performance equipment.

The tundish is installed at the upper part of the performance equipment, and receives molten steel from the ladle and supplies molten steel to the mold installed at the lower part through the immersion nozzle.

The molten steel supplied to the mold is discharged to the lower part of the mold as the surface is solidified, and then formed into intermediate products such as slabs, beam blanks, billets, etc., passing through a plurality of rolling rolls through the strands.

On the other hand, the molten steel includes a number of non-metallic inclusions.

The present invention is to remove the inclusions of the molten steel in the tundish to prevent clogging of the immersion nozzle to facilitate continuous casting, and also the molten steel of the tundish to improve the cast quality by reducing the defects of the produced cast It is an object to provide an apparatus for removing an inclusion.

The present invention for achieving the above object,

A stopper having a slit formed therein;

Porous refractory is installed on the outer side of the slit and exposed to molten steel;

An argon gas tank in which argon gas is stored;

A supply pipe connecting the slit and the argon gas tank;

.

In addition, a through hole penetrating the center of the stopper is formed,

The through hole is connected to the supply pipe by a branch supply pipe.

In addition, the lower end of the through-hole is characterized in that the nozzle hole is formed.

In addition, a valve is installed in the supply pipe and the branch supply pipe.

In addition, the supply pipe and the branch supply pipe is characterized in that disposed along the stopper arm is mounted with the stopper.

In addition, the supply pipe and the branch supply pipe is characterized in that mounted via a mounting bracket.

According to the present invention as described above,

Through the porous refractory, argon gas can be discharged to the entire range of the stopper's surroundings, so that argon gas can be supplied to a wider range, thereby improving performance of trapping molten steel inclusions.

In addition, since the argon gas can be ejected through the nozzle hole even below the stopper, inclusions can be prevented from adhering and growing on the inner wall of the immersion nozzle.

Therefore, clogging of the immersion nozzle by the non-metallic inclusions is prevented, so that it is not necessary to stop the performance of the operation to remove the adhesion inclusions, and the defects in the cast product are prevented by reducing the inclusion components in the molten steel, thereby improving quality.

In addition, the supply pipes supplying the argon gas into the stopper are arranged and arranged on the stopper arm, thereby preventing breakage of the supply pipes during the stopper operation.

1 is an installation state diagram of the molten steel inclusion removal device of the tundish according to the present invention,
2 is a block diagram of a molten steel inclusion removal device of the tundish according to the present invention,
Figure 3 is a view showing another embodiment of the molten steel inclusion removal apparatus of the tundish according to the present invention.

Hereinafter, with reference to the accompanying drawings, the present invention will be described in detail.

As illustrated in FIG. 1, an immersion nozzle 2 is provided at the lower portion of the tundish 1 to prevent the molten steel from being oxidized by supplying the molten steel to the mold without contact with air.

A tundish cover is provided on an upper portion of the tundish 1, and a stopper 3 operating hole is formed in the tundish cover.

The stopper 3 is connected to the stopper arm 4 installed on the outer upper part of the tundish 1, and the stopper arm 4 is movable up and down by the cylinder 5.

Therefore, as the cylinder 5 raises or lowers the stopper arm 4, the stopper 3 is raised or lowered, and the lower end of the stopper 3 moves the immersion nozzle 2 according to its up and down position. Opening or blocking is also performed, and the amount of molten steel is increased or decreased by adjusting the opening degree of the immersion nozzle 2.

As shown in FIG. 2, the present invention includes a stopper 3 having a slit 3a formed therein, a porous refractory 3b installed at an outer side of the slit 3a and exposed to molten steel, and argon gas. Argon gas tank 6, and the supply pipe 7 for connecting the slit (3a) and the argon gas tank (6).

The slit 3a is formed adjacent to the surface in the stopper 3, and is formed in a cylindrical shape.

Porous refractory 3b is installed at an outer portion of the slit 3a, and an outer surface of the porous refractory 3b is exposed to the outside of the stopper 3.

That is, the inner surface of the porous refractory 3b is in contact with the inner space of the slit 3a, and the outer surface is in contact with the molten steel in the tundish 1.

In addition, the porous refractory 3b is formed only in the formation range of the slit 3a.

That is, if the slit 3a is not formed in a cylindrical shape over the entire circumferential direction of the stopper 3, but is formed in a predetermined range at regular intervals along the circumferential direction, the porous refractory 3b is also along the circumferential direction. It is divided into a plurality and formed so as to cover the outer portion (the surface side direction of the stopper) of the slit 3a.

The porous refractory (3b) has a porosity of about 18%, the gas can be communicated through the pores.

On the other hand, the argon gas tank 6 means an argon gas supply source, and does not necessarily need to be a storage tank, and may be an argon gas supply pipe installed in the factory.

The supply pipe 7 connects the argon gas tank 6 and the slit 3a of the stopper 3 and is configured using a hose and a pipe. In particular, the portion adjacent to the stopper 3 should be made of a heat resistant material.

In addition, the supply pipe 7 is provided with a valve 8 for supplying or blocking argon gas.

The valve 8 may be manually operated by an operator or may be automatically operated by a computer for controlling a performance facility.

3 shows another embodiment of the present invention.

As shown, the stopper 3 is formed with a through hole 3c throughout the vertical direction.

The through hole 3c is connected to a branch supply pipe 9 branched from the supply pipe 7, and a valve 10 is installed in the branch supply pipe 9 to open and close the pipeline.

Now, the operation and effect of the present invention will be described.

In the embodiment of FIG. 2, when the valve 8 is opened, argon gas is supplied from the argon gas tank 6 to the slit 3a of the stopper 3 through the supply pipe 7.

Argon gas supplied to the slit 3a is blown out of the stopper 3 by passing through the pores of the porous refractory 3b.

That is, argon gas is injected into the molten steel through the porous refractory 3b.

The argon gas passes through the pores of the porous refractory 3b and is injected into the molten steel in the form of fine bubbles. After the injection, the argon gas is dispersed to the periphery of the stopper 3 to rise to the surface of the molten steel.

At this time, non-metallic inclusions contained in molten steel are collected in the gas bubble and float together.

The non-metallic inclusions floated as described above are trapped and removed from the slag existing on the molten steel surface.

Therefore, the content of the non-metallic inclusions contained in the molten steel is reduced, thereby improving the quality of the manufactured product.

In addition, the amount of the inclusions may be reduced to reduce the degree of inclusion of the inclusions on the inner wall of the immersion nozzle 2.

Meanwhile, the embodiment of FIG. 3 further includes a through hole 3c that vertically penetrates the center of the stopper 3 in addition to the embodiment of FIG. 2.

Therefore, argon gas can be ejected to the lower part of the stopper 3 through the through-hole 3c by opening the valve 10 installed in the branch supply pipe 9.

The lower end of the through hole 3c is formed of a nozzle hole 3d having a reduced inner diameter, so that argon gas can be ejected quickly and strongly.

Accordingly, when the stopper 3 is lowered to approach the immersion nozzle 2 and the valve 10 of the branch supply pipe 9 is opened to supply argon gas, the argon gas is immersed through the nozzle hole 3d. It can spray strongly inside (2).

Therefore, inclusions are attached to the inner wall of the immersion nozzle 2, and it is possible to reliably prevent growth.

Therefore, the phenomenon that the molten steel passage area of the immersion nozzle 2 decreases or is not blocked due to inclusion and growth of inclusions on the inner wall of the nozzle does not occur.

Therefore, the molten steel can be precisely controlled through the stopper 3 control, so that continuous casting can be performed more smoothly.

In addition, the present invention controls the two valves (8, 10) to discharge the argon gas only through the porous refractory (3b), or to eject only through the nozzle hole (3d), or to be discharged from both places. Can be.

Therefore, argon gas discharge method can be selected and used as needed.

On the other hand, when argon gas is simultaneously discharged through the porous refractory 3b and the nozzle hole 3d in the state where the stopper 3 is raised, the nozzle is discharged to the gas bubble discharged around the stopper through the porous refractory 3b. As gas bubbles are discharged to the lower part of the stopper 3 through the holes 3d and rise, the upflow in the molten steel can be made stronger, non-metallic inclusions in the molten steel are more actively floated and collected and removed in the slag.

On the other hand, as shown in Figure 1, the argon gas supply pipe 7 and the branch supply pipe 9 connected to the stopper 3 side is preferably arranged along the stopper arm (4).

As described above, when the supply pipes (7, 9) are installed on the stopper arm (4) it is possible to prevent the stopper arm (4) and the supply pipes (7, 9) from being damaged due to mutual interference when the stopper (3) lifting and lowering control .

To this end, the supply pipes 7 and 9 are installed to the stopper arm 4 via a mounting bracket 11.

The mounting bracket 11 is mounted to the stopper arm 4 by fastening means such as bolts and fixing pins, and a plurality of mounting brackets 11 are installed along the longitudinal direction of the stopper arm 4 to stably fix the supply pipes 7 and 9. I can do it.

1: tundish 2: immersion nozzle
3: stopper 3a: slit
3b: porous refractory 3c: through hole
3d: nozzle hole 4: stopper arm
5: cylinder 6: argon gas tank
7: supply pipe 8: valve
9: branch supply pipe 10: valve

Claims

A stopper having a slit formed therein;
Porous refractory is installed on the outer side of the slit and exposed to molten steel;
An argon gas tank in which argon gas is stored;
A supply pipe connecting the slit and the argon gas tank;
Molten steel inclusion removal device of a tundish comprising a.

The method according to claim 1,
A through hole penetrating the center is formed in the stopper,
The through-hole is a molten steel inclusion removal device of the tundish, characterized in that connected to the supply pipe by a branch supply pipe.

The method according to claim 2,
The tungsten molten steel inclusion removal device, characterized in that the lower end of the through hole is reduced in diameter to form a nozzle hole.

The method according to claim 2,
The molten steel inclusion removal device of the tundish, characterized in that the valve is installed in the supply pipe and the branch supply pipe.

The method according to claim 2,
And said supply pipe and said branch supply pipe are disposed along a stopper arm on which said stopper is mounted.

The method according to claim 5,
The supply pipe and the branch supply pipe is molten steel inclusion removal device of the tundish, characterized in that mounted via a mounting bracket.