KR20150028868A - Refining furnace having apparatus for preventing nitrogen suction - Google Patents

Refining furnace having apparatus for preventing nitrogen suction Download PDF

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Publication number
KR20150028868A
KR20150028868A KR20130100529A KR20130100529A KR20150028868A KR 20150028868 A KR20150028868 A KR 20150028868A KR 20130100529 A KR20130100529 A KR 20130100529A KR 20130100529 A KR20130100529 A KR 20130100529A KR 20150028868 A KR20150028868 A KR 20150028868A
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KR
South Korea
Prior art keywords
refining furnace
molten steel
nitrogen
opening
moving part
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KR20130100529A
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Korean (ko)
Inventor
류재왕
Original Assignee
주식회사 포스코
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Priority to KR20130100529A priority Critical patent/KR20150028868A/en
Publication of KR20150028868A publication Critical patent/KR20150028868A/en

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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/28—Manufacture of steel in the converter
    • C21C5/38—Removal of waste gases or dust
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/28—Manufacture of steel in the converter
    • C21C5/42—Constructional features of converters
    • C21C5/46—Details or accessories
    • C21C5/4633—Supporting means
    • C21C5/464—Trunnion bearings

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Environmental & Geological Engineering (AREA)
  • Treatment Of Steel In Its Molten State (AREA)

Abstract

The present invention relates to a refining furnace equipped with a nitrogen absorption preventing device capable of preventing atmospheric nitrogen from being sucked into molten steel during refining furnace operation by argon atmosphere around a molten steel from an opening of a refining furnace to a ladle. The refining furnace provided with the nitrogen absorption preventing device according to the present invention includes a refining furnace body portion having molten steel therein and an opening at an upper end thereof; And a nitrogen injection preventing device disposed adjacent to the opening, wherein the nitrogen suction preventing device includes a gas moving part formed around the opening part, at least one first injection hole formed to face the upper part of the opening part of the gas moving part, And at least one second injection hole formed to face the center of the opening in the gas moving part. By such a constitution, quality defects of molten steel can be prevented, productivity can be improved, and cost can be reduced.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a refining furnace having a nitrogen-

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refining furnace equipped with a nitrogen suction preventing device, and more particularly, to a refining furnace equipped with a nitrogen suction preventing device capable of improving the quality of molten steel.

In order to make the molten iron produced in the blast furnace into a strong steel, the steelmaking process reduces the amount of carbon and removes impurities. This steelmaking process consists of an electric arc furnace (EAF) - Argon Oxygen Decarburization (AOD) - ladle refining (LT) - continuous casting process.

In the electric furnace, a preliminary ironing process for removing phosphorus (P) and sulfur (S) components contained in the molten iron is performed. Then, the molten steel is poured into the refining furnace, and high-pressure and high-purity oxygen is blown to burn carbon and remove impurities. Thereafter, the molten steel in the refining furnace is led to the ladle, the components of the molten steel are adjusted, and then the continuous casting is performed.

The object of the present invention is to provide a refining furnace equipped with a nitrogen suction preventing device capable of preventing nitrogen in the atmosphere from being sucked into molten steel during refining furnace pouring operation by making argon atmosphere around the molten steel from the opening at the upper end of the refining furnace to the ladle .

The refining furnace provided with the nitrogen absorption preventing device according to the present invention includes a refining furnace body portion having molten steel therein and an opening at an upper end thereof; And a nitrogen injection preventing device disposed adjacent to the opening, wherein the nitrogen suction preventing device includes a gas moving part formed around the opening part, at least one first injection hole formed to face the upper part of the opening part of the gas moving part, And at least one second injection hole formed to face the center of the opening in the gas moving part.

Here, the gas moving part may be formed in a ring shape having a space therein.

The gas moving part may be provided on the body of the refining furnace by a first bearing, and the gas moving part may be rotatable about the first bearing.

Further, the first bearings may be formed as a pair.

Further, the pair of first bearings may be formed at positions mutually symmetrical with respect to the center of the refining furnace body portion.

In addition, the first bearing may be connected to a gas supply part.

At this time, the gas supply unit may be connected to the center of the first bearing.

The gas supplied from the gas supply unit may include argon gas.

In addition, a region of the gas supply unit may include a valve for supplying or blocking gas.

Further, a cylinder having one side fixed to the refining furnace body and the other side fixed to the gas moving part may be included.

Here, the cylinder is installed in the body of the refining furnace by a second bearing, and the gas moving part can be adjusted to be inclined at a certain angle.

According to the present invention, it is possible to prevent quality defects of molten steel by blocking nitrogen from being absorbed into molten steel during the refining furnace pouring operation by making argon atmosphere around the molten steel from the opening at the upper end of the refining furnace to the ladle.

According to the present invention, the reprocessing operation of molten steel due to quality defects of molten steel is unnecessary, thereby reducing the reprocessing cost of molten steel and preventing the production stoppage of the molten steel before and after the molten steel reprocessing work.

Further, according to the present invention, since the nitrogen in the atmosphere is completely prevented from being sucked into the molten steel, the worker can perform the standardized work, so that the work load is remarkably reduced, and the productivity and the cost can be reduced.

1A is a perspective view showing a general refining furnace;
Fig. 1B is a perspective view showing a state in which molten steel is introduced into the ladle from the refining furnace of Fig. 1A. Fig.
2 is a perspective view showing a state in which a nitrogen suction preventing device is installed in a refining furnace according to the present invention.
3 is a perspective view showing a state before operation of the nitrogen absorption prevention apparatus according to the present invention.
4 is a cross-sectional view taken along line A-A 'of Fig. 3;
5 is a perspective view showing the operation state of the nitrogen absorption prevention apparatus according to the present invention.
6 is a perspective view showing a state in which molten steel is introduced into a ladle from a refining furnace provided with a nitrogen absorption preventing device according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to embodiments of the present invention and other details necessary for those skilled in the art to understand the present invention with reference to the accompanying drawings. However, the present invention may be embodied in many different forms within the scope of the appended claims, and therefore, the embodiments described below are merely illustrative, regardless of whether they are expressed or not.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. It should be noted that the same components in the drawings are denoted by the same reference numerals and signs as possible even if they are shown in different drawings. In addition, the thickness and size of each layer in the drawings may be exaggerated for convenience and clarity, and may differ from actual layer thicknesses and sizes.

FIG. 1A is a perspective view showing a general refining furnace, and FIG. 1B is a perspective view showing a state in which molten steel is introduced into the ladle from the refining furnace of FIG. 1A.

Referring to FIGS. 1A and 1B, a molten metal spouted in an electric furnace is housed in a refining furnace body portion 20 using a crane, and performs a blowing operation using an oxygen lance 10. The steel components and temperature required in the post-process are adjusted by the blow-in operation, and when the quality requirements of a certain post-process are satisfied, the work is performed.

The ladle 30 is moved to the lower portion of the refining furnace body 20 and the refractory furnace body 20 is tilted to guide the molten steel 60 into and out of the ladle 30 for pouring work. At this time, the nitrogen (50) distributed in the air comes into contact with the surface of the molten steel (60). The nitrogen 50 in contact with the surface of the molten steel 60 is sucked into the molten steel 60 and the nitrogen 50 is sucked into the molten steel 60 to cause quality defects.

When the quality defect of the molten steel 60 due to the inhalation of the nitrogen 50 occurs, the molten steel 60 should be charged again into the refining furnace body 20 for reprocessing work. And, in order to perform such a reprocessing operation, enormous energy must be supplied again. In addition, there is a problem that the work before and after the lapping operation is delayed, and the productivity is lowered.

In general, in order to prevent the nitrogen 50 from being sucked into the molten steel 60, an argon (Ar) pipe is inserted into the ladle 30 to prevent the nitrogen 50 from contacting the molten steel 60 . However, there has been a problem in that ambient air is sucked in along with the process of injecting argon into the ladle 30. In addition, since nitrogen 50 can be prevented from being sucked in only the portion where argon is injected, it is basically impossible to prevent the nitrogen 50 from being sucked into molten steel 60. Accordingly, quality defects of the molten steel (60) due to the inhalation of the nitrogen (50) continue to occur even when the above method is used.

In order to prevent the nitrogen 50 from being sucked into the molten steel 60, in order to minimize the contact portion between the atmosphere and the molten steel 60, the pouring operation is slowed to prevent the nitrogen 50 from being sucked. However, problems such as delay in working time and lowering of molten steel temperature are not solved, and the problem that the essential nitrogen (50) is sucked in can not be solved, so that the production cost due to quality defects and reprocessing work is increased, It is becoming a factor.

During the refining furnace 20 working process, the oxygen lance 10 installed on the upper part serves to burn carbon in the molten steel 60. The ladle 30 containing the molten steel 60 is moved to the lower portion of the refining furnace 20 and then the refining furnace 20 is tilted to perform the ladle operation. The nitrogen 50 distributed in the air is contacted with the surface of the molten steel 60 while the molten steel 60 having been treated in the refining furnace 20 of the steelmaking process is charged into the ladle 30, Is sucked into the molten steel (60).

Accordingly, the present invention provides a refining furnace (20) provided with a nitrogen absorption prevention device (100) capable of preventing nitrogen (50) in the atmosphere from being sucked into molten steel (60) during refining furnace operation. The nitrogen absorption preventing device 100 prevents the nitrogen 50 from being sucked into the molten steel 60, thereby preventing quality defects of the molten steel and producing a high-quality molten steel 60.

2 is a perspective view showing a state in which a nitrogen suction preventing device is installed in a refining furnace according to the present invention.

2, the refining furnace provided with the nitrogen absorption preventing apparatus 100 according to the present invention includes a refining furnace body 20 for accommodating molten steel 60 (see FIG. 1B) and a refining furnace body 20). The nitrogen adsorption preventing device (100) is installed in one region. An opening 40 is formed at an upper end of the refining furnace body 20 and a nitrogen absorption preventing device 100 is installed adjacent to the opening 40.

This nitrogen inhalation prevention apparatus 100 includes a gas moving part 105, a first injection hole 110 and a second injection hole 120 (see FIG. 3). The gas moving part 105 is formed around the opening 40 of the refining furnace body part 20 and at least one of the first injection holes 110 is formed in the gas moving part 105 so as to face the upper part of the opening part 40 And at least one of the second injection holes 120 is formed in the gas moving portion 105 so as to face the center of the opening portion 40. At this time, the gas moving part 105 may be formed into a ring shape having a space therein.

The ring-shaped gas moving part 105 is installed in the refining furnace body part 20 and the gas moving part 105 is installed in the refining furnace body part 20 by the first bearing 140. The pair of first bearings 140 are formed at positions symmetrical with respect to the center of the refining furnace body 20. Whereby the gas moving part 105 is formed so as to be rotatable around the pair of first bearings 140.

A gas supply unit 160 is connected to the first bearing 140, and argon gas is supplied from the gas supply unit 160. At this time, one region of the gas supply unit 160 may include a valve 150 for supplying or blocking gas. Further, the cylinder 130 is installed so that the gas moving part 105 can be adjusted to be inclined at a certain angle. One side of the cylinder 130 is fixed to the refining furnace body 20 and the other side of the cylinder 130 is fixed to the gas moving part 105. At this time, the cylinder 130 is installed in the refining furnace body 20 by the second bearing 131.

According to the present invention thus configured, it is possible to prevent the nitrogen 50, which is distributed in the air, from being sucked into the molten steel 60 during the process of storing the molten steel 60 processed in the refining furnace body 20 into the ladle 30 .

FIG. 3 is a perspective view showing a state before operation of the nitrogen absorption prevention apparatus according to the present invention, and FIG. 4 is a sectional view taken along line A-A 'of FIG.

3 and 4, the gas moving part 105 of the nitrogen suction preventing device 100 is installed in the refining furnace body 20 (see FIG. 2) by a pair of first bearings 140. The pair of first bearings 140 are formed at symmetrical positions with respect to the center of the refining furnace body 20 so that the gas moving part 105 is rotatable about the first bearing 140 .

At least one first injection hole 110 and a second injection hole 120 through which argon is injected are formed in the ring-shaped gas moving part 105 of the nitrogen absorption prevention device 100. The first injection hole 110 is formed in the direction toward the upper portion of the refining furnace body portion 20, that is, in the direction of the opening portion 40 of the refining furnace body portion 20, and the second injection hole 120 is refined In the direction toward the center of the body 20. That is, when the upper side of the refining furnace body portion 20 is 0 °, the first injection holes 110 are formed in the 0 ° direction and the second injection holes 120 are formed in the 90 ° clockwise direction do.

Argon sprayed in the first injection hole 110 is tightly wrapped with argon around the molten steel being introduced to prevent nitrogen from contacting the molten steel. The second injection hole 120, which faces the center of the opening of the refining furnace body 20, shields the nitrogen from being introduced into the side surface of the nitrogen absorption preventing device 100.

FIG. 5 is a perspective view showing a state during operation of the nitrogen absorption prevention apparatus according to the present invention. FIG.

Referring to FIG. 5, when the refining furnace starts the laminating operation and the refining furnace body portion 20 is inclined, the nitrogen absorption preventing device 100 is inclined together with the angle of inclination of the refining furnace body portion 20 . This is accomplished by the operation of the cylinder 130 installed in the nitrogen absorption prevention apparatus 100. In addition, in order to facilitate the inclination of the nitrogen absorption prevention device 100, the nitrogen absorption prevention device 100 is formed to be rotatable by the first bearing 140 on the refining furnace body 20. At this time, the first bearings 140 are formed in a pair, and the pair of first bearings 140 are formed at positions mutually symmetrical with respect to the center of the opening 40 of the refining furnace body 20. [ Whereby the molten steel 60 is injected from the opening 40 to the ladle 30 so as to surround the argon gas.

When the refining furnace body 20 tilts and the molten steel 60 is discharged to the outside through the opening 40 of the refining furnace body 20, the argon discharge valve 150 is opened and argon is injected. The gas supply unit 160 which is a pipe connected to the argon dust use valve 150 is configured to be connected to the center of the first bearing 140 of the nitrogen suction prevention apparatus 100 so that even when the refractory body body 20 is rotated, Make sure there is no gas leakage.

6 is a perspective view showing a state in which molten steel is introduced into a ladle from a refining furnace equipped with a nitrogen suction preventing device according to the present invention.

6, the injection hole through which the argon is injected in the nitrogen absorption preventing apparatus 100 includes a first injection hole 110 formed in the 0 ° direction on the upper side of the refining furnace body portion 20 and a second injection hole 110 formed in the refining furnace body 20 And a second ejection hole 120 formed in a 90 ° direction toward the center of the opening 40 of the first ejection opening. The first injection hole 110 is configured to prevent nitrogen from contacting the molten steel 60 and surround the molten steel 60 around the molten steel 60 with argon. The second injection hole 120 is configured to shield nitrogen from flowing into the side surface of the nitrogen absorption prevention device 100.

When the refining furnace body portion 20 is inclined and starts to run, the nitrogen absorption preventing device 100 moves the cylinder 130 for operating the nitrogen absorption preventing device 100 so as to face the ladle 30 . When the opening 40 of the refining furnace body 20 approaches the downward direction, that is, 180 degrees, the nitrogen absorption preventing device 100 is tilted from the initial state by about 180 degrees, 20 prevents the molten steel 60 from contacting with the nitrogen 50 in the atmosphere during the entire process of introducing the molten steel 60.

When the refractory furnace body 20 is inclined to go out the molten steel 60 and the molten steel 60 is discharged to the outside of the refining furnace body 20. The nitrogen suction prevention device 100 is inclined in the direction of the running direction. The argon discharge valve 150 is opened to prevent the molten steel 60 from coming into contact with nitrogen so as to argon the atmosphere around the molten steel from the opening of the refining furnace body portion 20 to the ladle 30.

Hereinafter, the operation of the refining furnace equipped with the nitrogen absorption prevention device according to the present invention will be described in detail.

The present invention configured as described above has a function of preventing the molten steel (60) from coming into contact with the nitrogen (50) in the atmosphere during the pouring work of the refining furnace (20). The cylinder 130 of the nitrogen absorption prevention device 100 is operated so that the nitrogen absorption prevention device 100 is connected to the refining furnace body 20 It tilts in the same direction. At this time, the argon discharge valve 150 connected to the nitrogen suction prevention device 100 is opened and supplied to the gas moving part 105 through the gas supply part 160.

Argon gas is injected through the first injection hole 110 and the second injection hole 120 of the gas moving part to prevent the molten steel 60 from contacting with the nitrogen 50 in the atmosphere. The argon gas injected from the first injection hole 110 is injected in the direction of the ladle 30 and the argon gas injected from the second injection hole 120 is injected into the nitrogen intake preventing device 100 and the refining furnace body 20, Thereby shielding nitrogen from the atmosphere.

When the refining furnace body portion 20 is inclined and starts to run, the nitrogen absorption preventing device 100 is inclined together by the operation of the cylinder 130 so as to face the ladle 30. At this time, the nitrogen absorption preventing device 100 acts to move together with the tilting angle change of the refining furnace body portion 20, so argon is always injected in the direction of the ladle 30.

The cylinder 130 of the nitrogen absorption prevention device 100 moves to the maximum position and the nitrogen absorption prevention device 100 when the tilting angle of the refining furnace body portion 20 approaches the downward direction, Is rotated 180 degrees from the initial state. The molten steel 60 can be prevented from being in contact with nitrogen in the atmosphere during the entire process of introducing the molten steel 60 from the refining furnace body 20. That is, it is possible to prevent the quality defect due to the nitrogen inhalation by completely preventing the molten steel 60 from contacting the nitrogen during the lubrication.

Further, the reprocessing work of the molten steel 60 due to quality defects is prevented in advance, so that the reprocessing cost of the molten steel 60 can be greatly reduced, and the cost of the pre- It is possible to prevent the production stoppage. In particular, by completely preventing nitrogen inhalation from the molten steel 60, not only can the quality of the molten steel 60 be greatly improved, but also the workload can be largely reduced by a standardized work, You can contribute.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It will be apparent to those skilled in the art that various modifications may be made without departing from the scope of the present invention.

The scope of the present invention is defined by the following claims. The scope of the present invention is not limited to the description of the specification, and all variations and modifications falling within the scope of the claims are included in the scope of the present invention.

10: oxygen lance 20: refining furnace body part
30: ladle 40: opening
60: molten steel 100: nitrogen suction prevention device
110: first injection hole 120: second injection hole
130: cylinder 131: second bearing
140: first bearing 150: valve

Claims (11)

A refining furnace body portion accommodating molten steel therein and having an opening at an upper end thereof; And
And a nitrogen absorption preventing device installed adjacent to the opening,
The nitrogen suction preventing device comprises:
And a second injection hole formed in the gas moving part so as to face the center of the opening, and a second injection hole formed in the gas moving part so as to face the upper part of the opening, A refining furnace equipped with a suction preventing device. The method according to claim 1,
Wherein the gas moving unit is formed in a ring shape having a space therein. The method according to claim 1,
Wherein the gas moving part is provided on the body of the refining furnace by a first bearing, and the gas moving part is formed to be rotatable about the first bearing. The method of claim 3,
Wherein the first bearing is formed as a pair. 5. The method of claim 4,
Wherein the pair of first bearings are formed at positions mutually symmetrical with respect to the center of the refining furnace body portion. The method of claim 3,
Wherein the first bearing is connected to a gas supply unit. The method according to claim 6,
And the gas supply unit is connected to the center of the first bearing. The method according to claim 6,
Wherein the gas supplied from the gas supply unit includes argon gas. The method according to claim 6,
And a valve for supplying or blocking a gas to one region of the gas supply unit. The method according to claim 1,
A refining furnace including a cylinder having one side fixed to the refining furnace body and the other side fixed to the gas moving part. 11. The method of claim 10,
Wherein the cylinder is installed on the body of the refining furnace by a second bearing, and the gas moving part is inclined at a predetermined angle.
KR20130100529A 2013-08-23 2013-08-23 Refining furnace having apparatus for preventing nitrogen suction KR20150028868A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20190018072A (en) * 2017-08-10 2019-02-21 주식회사 포스코 Casting ladle for preventing nitrogen absorption and method for preventing nitrogen absorption using the same
KR20200063819A (en) * 2018-11-28 2020-06-05 주식회사 포스코 Apparatus for discharging molten steel in converter

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20190018072A (en) * 2017-08-10 2019-02-21 주식회사 포스코 Casting ladle for preventing nitrogen absorption and method for preventing nitrogen absorption using the same
KR20200063819A (en) * 2018-11-28 2020-06-05 주식회사 포스코 Apparatus for discharging molten steel in converter

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