KR101412312B1 - Electric furnace - Google Patents

Abstract

The present invention relates to an electric furnace, and more particularly, to an electric furnace, and more particularly, to an electric furnace, and more particularly, to an electric furnace which comprises a slag outlet port provided separately from a molten steel outlet port for opening / closing the upper door member and the lower door member by upward / downward movement, So that the slag outlet can be stably opened and closed for a long period of time and the maintenance cost is reduced.

Description

Electric furnace {ELECTRIC FURNACE}

The present invention relates to an electric furnace, and more particularly, to an electric furnace capable of stably operating a door that opens and closes a slag outlet provided separately from a molten steel outlet.

Generally, an electric furnace is a furnace in which electric energy is used to heat and dissolve a metal or an alloy. After charging scrap into the furnace, an arc current is generated between the electrode and the scrap to heat the scrap.

During the steelmaking operation of the electric furnace, the impurities in the scrap are dissolved and slag is formed in the form of oxide in the upper part of the molten steel.

The slag is deposited on the surface of the molten steel to prevent the surface of the molten steel from being oxidized by air and to preserve the surface of the molten steel. Mass transfer and chemical reaction take place at the interface between the slag and the molten steel.

Japanese Patent Application Laid-Open No. 10-2001-0013939 discloses a method for determining slag forming in an electric furnace steelmaking method and a method for operating an electric furnace (disclosed on Feb. 26, 2001).

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electric furnace capable of stably operating a door for opening and closing a slag discharge port and further increasing durability.

The present invention provides an electric furnace main body in which a space portion in which scrap is charged and melted is provided therein and a molten steel discharge port for discharging molten steel and a slag discharge port for discharging slag separately from the molten steel discharge port are formed;

An upper door member for opening and closing an upper portion of the slag outlet;

An upper door movement device for moving the upper door member up and down;

A lower door member for opening and closing a lower portion of the slag outlet;

A lower door moving device for moving the slag outlet upward and downward; And

And an electric furnace including a heat sink member spaced apart from a lower portion of the lower door mobile device.

In the electric furnace according to the present invention, the heat sink member is mounted obliquely, and the tilted end side is opened.

In the electric furnace according to the present invention, the heat dissipation plate member may include a heat dissipation plate part having one end rotatably connected to the support body; And a panel rotating part for rotating the heat sink part.

 In the electric furnace according to the present invention, hard coat layers are respectively formed on the front and rear surfaces of the lower door member.

In the electric furnace according to the present invention, it is preferable that the electric furnace is disposed on the rear side of the lower door member disposed toward the inside of the electric furnace and guides the upward and downward movement of the lower door member and the upper door member, A first guide plate member having an outlet formed therein; And a second guide plate member disposed on a front side of the lower door member and guiding the upward and downward movement of the lower door member and the upper door member and having a second discharge port for discharging the slag, A plurality of support portions spaced apart from a lower portion of the first guide plate member are protruded, and a space is formed between the plurality of support portions.

In the electric furnace according to the present invention, the upper door member may include: a door plate portion for opening and closing an upper portion of the slag outlet; And a plurality of ribs protruding from the door plate toward the outside of the electric furnace.

The present invention has an effect of preventing leakage of slag during the steelmaking operation of an electric furnace to reduce heat loss due to slag discharge, increase the efficiency of arc heat by forming foam slag, and recover the molten metal in molten slag to increase the recovery rate of molten steel .

According to the present invention, the durability of the door for opening and closing the slag outlet is increased, and the slag outlet can be stably opened and closed for a long period of time, thereby reducing the maintenance cost.

1 is a schematic view showing an electric furnace according to the present invention;
2 is an enlarged view of a slag outlet portion in an electric furnace according to the present invention;
3 is a schematic view showing a door structure for opening and closing a slag outlet in an electric furnace according to the present invention.
4 is an exploded perspective view showing a door structure for opening and closing a slag discharge port in an electric furnace according to the present invention.
5 is a front view showing an example of an upper door member in an electric furnace according to the present invention.
6 is a perspective view showing another example of the upper door member in the electric furnace according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 1, an electric furnace according to the present invention includes an electric furnace main body 1 having a space portion in which scrap is charged and dissolved therein. The electric furnace main body 1 is divided into a lower body portion 1b and an upper body portion 1a so that an inner wall of the lower body portion 1b is formed with a refractory wall formed with a refractory softener to protect the outer wall, In the inner side wall of the body portion, a cooling panel member for circulating cooling water to the inside and protecting the outer wall is generally mounted. In the upper part of the electric furnace 1, an electric furnace ceiling member 2 having a plurality of electrode bars 2a for covering the open top and generating arc heat is coupled.

Although not shown, an exhaust pipe for discharging a large amount of waste gas and dust generated in the melting process is connected to the electric furnace ceiling member 2.

On one side of the electric furnace main body 1, there is provided a molten steel discharge port (not shown) for discharging molten steel produced by dissolving scrap in the space portion. In addition, the electric furnace main body 1 is formed with a slag discharge port 1c separately from the molten steel discharge port. The slag outlet 1c is formed separately from the molten steel discharge port to discharge slag generated during the steelmaking operation in the electric furnace main body 1.

The slag outlet 1c is provided with an upper door member 10 which is moved upward and downward to open and close the upper portion of the slag outlet 1c.

The slag outlet 1c is provided with a lower door member 30 which is moved upward and downward to open and close the lower portion of the slag outlet 1c.

The lower door member 30 protrudes to the upper side of the slag outlet 1c to prevent the slag discharged through the slag outlet 1c from flowing out.

The slag formed on the surface of the molten steel in the steelmaking operation of the electric furnace is expanded in volume during the oxidative refining and carbonation process, and the expanded slag flows into the slag discharge port 1c and is discharged. As described above, the initial slag expanded and formed in the oxidation refining process contains a large amount of oil-soluble metal oxides such as iron oxide (FeO).

The lower door member 30 is raised and lowered at a height higher than the height of the slag at the slag outlet 1c through which the slag flows out during slag volume expansion due to slag forming in the oxidation refining process, Thereby blocking a portion of the slag from flowing out of the initial slag. Further, the lower door member 30 is lowered to discharge the slag. Further, when the slag solidifies on the upper surface guiding the discharge of the slag from the slag outlet 1c, it also lifts and removes the solidified slag.

The upper door member 10 is capable of opening and closing the slag outlet 1c at an upper portion of the lower door member 30. That is, the lower door member 30 is protruded to the upper portion of the slag outlet guide support member to move the upper door member 10 upward so as to partially open the slag outlet 1c, You can.

Accordingly, during the steelmaking operation such as oxidization refining, the upper door member 10 is moved upward to open the slag outlet 1c, and a water-cooling lance or a thermometer can be drawn into the electric furnace. In addition, the upper door member 10 is lowered to a height that does not contact the slag when the lower door member 30 is lowered to discharge the slag, so that when the slag is discharged, external discharge of the internal furnace of the electric furnace, It prevents leakage and prevents the inflow of outside air to the utmost.

On the other hand, a heat sink member 50 is installed on the lower side of the slag outlet 1c. The heat sink member 50 blocks heat transmitted to the upper side from the slag storage port (not shown) for storing the slag discharged from the slag discharge port 1c so that the lower door member 30 and the upper door member 10 ). The heat radiating plate member 50 also serves as a work support for easily maneuvering the door structure including the lower door member 30 and the upper door member 10 for opening and closing the slag outlet 1c .

Although not shown, when the slag is discharged through the slag outlet 1c, a slag port (not shown) for storing the discharged slag is disposed below the slag outlet 1c. The upper portion of the slag port is opened to receive and store slag, and high temperature is transferred from the high temperature slag stored therein to the open upper side.

The heat sink member (50) is transferred from the hot slag to the open upper side. The air heated by the high temperature of the slag is discharged. The heat dissipation plate member 50 shields the door structure 30 which blocks the high heat transmitted from the upper portion of the slag port and opens and closes the slag discharge port 1c including the lower door member 30 and the upper door member 10 do.

Preferably, the heat sink member 50 is mounted to be inclined and the tilted end side is opened so that foreign substances can be discharged.

The heat dissipation plate member 50 includes a heat dissipation plate portion 51 having one end rotatably connected to the support body;

And a panel rotating part 52 for rotating the heat sink part 51.

The panel rotation part 52 includes a connection wire 52a connected to the other end side of the heat sink part 51;

A take-up reel 52b for winding and unwinding the connecting wire 52a by forward and reverse rotation by a motor;

So that the connecting wire 52a is guided to the take-up reel 52b and the connecting wire 52a is wound or unwound so as to move the other end side of the heat radiating plate portion 51 upwardly and downwardly And a guide roll 52c.

The heat radiating plate portion 51 is horizontally held in a state of being connected to the connection wire 52a so that the operator can safely perform a maintenance work and inspection work on the door structure thereon, So that it can be effectively blocked. When the slag or foreign matter accumulates in the upper part of the heat sink part 51, the panel rotating part 52 rotates the lower part of the heat sink part 51, and the other end part of the heat sink part 51 is lowered to discharge the slag or foreign substance accumulated on the upper part. The slag or foreign matter accumulated on the upper part of the heat sink part 51 may damage the cooling water pipe circulating inside the lower door member 30, so that it is preferable to periodically remove the slag or foreign matter.

The panel rotation part 52 releases the connection wire 52a from the take-up reel 52b to move the other end side of the heat dissipation plate part 51 downward and again connects the connection wire 52a to the take-up reel 52b So that the other end side of the heat sink part 51 is moved upward. The heat radiating plate portion 51 rotates about one end portion rotatably connected to the support by the operation of the panel rotation portion 52 and moves the other end portion up and down to selectively transmit slag or foreign matter accumulated on the upper portion . The connection wire 52a is preferably made of a metal material that is not deformed by the ambient temperature of the electric furnace main body 1. [ The panel rotating part 52 rotates the heat radiating plate part 51 through the connecting wire 52a so that the panel rotating part 52 can be disposed at a position where the slag port is not damaged at the position where the slag port is disposed, The portion 51 can be operated.

The heat radiating plate portion 51 and the guide roll 52c may be rotatably mounted on a support connected to the electric furnace main body 1 or may be rotatably mounted on a support provided on the floor .

Meanwhile, the upper door member 10 is moved up and down by the operation of the upper door mobile device 20. The lower door member 30 is moved upward and downward by the operation of the lower door mobile device 40. That is, the door structure of the present invention includes the upper door mobile device 20 and the lower door mobile device 40.

The upper door moving device (20) includes a door operating wire (21) connected to an upper portion of the upper door member (10);

An upper door operating portion 22 for pulling or pushing the door operating wire 21 to move the upper door member 10 up and down;

And a plurality of door actuators (22) which are rotatably mounted and guide the upper door member (10) upward and downward when the door operating wire (21) is pulled or pushed by the operation of the upper door actuating part And a guide roll member (23).

The upper door actuating part 22 is a hydraulic cylinder in which the piston rod is mounted so as to move upward and downward. The hydraulic cylinder pushes down the operating wire to lower the upper door member 10 when the piston rod moves upward. The hydraulic cylinder pulls up the operating wire to move the upper door member 10 when the piston rod moves downward. It is noted that the upper door moving device 20 can be modified to another example in which the upper door member 10 is moved up and down.

The lower door operating device includes an operation frame part 41 connected to a lower portion of the lower door member 30;

And a lower door operation part 42 for moving the operation frame part 41 up and down.

The lower door actuating part 42 is a hydraulic cylinder which is mounted to move the piston rod upward and downward and is connected to the operation frame part 41. [ The lower door operating part 42 includes a lower frame 41a connected to a lower surface of the lower door member 30; A vertical frame 41b vertically installed at one side of the lower frame 41a; And an upper frame 41c disposed horizontally above the vertical frame 41b and connected to the piston rod of the hydraulic cylinder.

The hydraulic cylinder moves the piston rod upward and downward to move the operation frame part 41 upward and downward so that the lower door member 30 is moved up and down so that the lower part of the slag outlet 1c Open and close.

4, the electric furnace according to the present invention is disposed on the rear side of the lower door member 30 disposed toward the inside of the electric furnace, and the lower door member 30, the upper door member 10, A first guide plate member 60 for guiding the upward and downward movement of the slag and having a first discharge port 61 for discharging the slag; And

A second discharge port 71 disposed on the front side of the lower door member 30 for guiding upward and downward movement of the lower door member 30 and the upper door member 10 and capable of discharging the slag And a second guide plate member (70) formed thereon.

A guide roller member 80 is rotatably mounted between the first guide plate member 60 and the second guide plate member 70 in contact with both side surfaces of the lower door member 30. The guide roller member 80 is rotatably mounted on either the first guide plate member 60 or the second guide plate member 70.

When the lower door member 30 moves upward and downward to open and close the first outlet 61 and the second outlet 71, the guide roller member 80 rotates the upper and lower door members 30, So that the lower door member 30 is smoothly moved up and down in the vertical direction.

Preferably, the lower door member 30 is formed with a hard coating layer on the rear surface and the front surface, respectively, and the hard coating layer 13 is based on Fe-Cr coating. The lower door member 30 has a hard coating layer formed on the rear surface and the front surface, respectively, which are in direct contact with the slag, thereby enhancing durability. That is, the high hardness coating layer formed on the rear surface of the lower door member 30 protects the surface of the lower door member 30 from the hot slag, facilitates the separation of the cooled and solidified slag on the surface, Thereby minimizing wear on the slag contact surface as the slag is dismounted.

The lower door member 30 is in contact with the first guide plate member 60 and the second guide plate member 70 disposed on the front and rear sides as described above, and guided upward and downward. The surface of the lower door member 30 is often worn due to the contact between the first guide plate member 60 and the second guide plate member 70 during operation.

When the front and back surfaces of the lower door member 30 are worn to cause a gap between the front and rear surfaces of the first guide plate member 60 and the second guide plate member 70 and the front and rear surfaces of the lower door member 30, The slag discharged at the generated intervals may flow in and solidify and the lower door member 30 may become inoperable.

A hard coat layer is formed on the front and rear surfaces of the lower door member 30 to minimize surface wear of the lower door member 30 during operation of the lower door member 30, (30).

Further, since the first guide plate member 60 is disposed on the rear side of the lower door member 30, which is in direct contact with the slag, the lower portion is frequently deformed due to the high heat of the slag. The lower portion of the first guide plate member 60 or the lower portion of the first outlet 61 may be in contact with the lower door member 30 when the lower door member 30 is deformed into a contact surface guiding upward / downward movement of the lower door member 30. [ Disable operation.

It is preferable that a plurality of support portions 62 spaced from the lower portion of the first guide plate member 60 are protruded and a space is formed between the plurality of support portions 62, The space is a space for preventing heat radiation and deformation, and prevents thermal deformation occurring in the lower portion of the first guide plate member (60).

Referring to FIG. 5, it is preferable that the upper door member 10 has a cooling water flow path 11 formed therein. Preferably, the upper door member 10 is cooled in a circulation structure in which cooling water flows into and out of the cooling water channel 11, thereby preventing thermal deformation due to high temperature during use.

Referring to FIG. 6, the upper door member 10 includes a door plate 13 for opening and closing an upper portion of the slag outlet 1c;

And a plurality of ribs 12 protruding from the door plate toward the outside of the electric furnace.

The upper door member 10 reinforces the rigidity of the door plate portion 13 by the rib portion 12 protruding from the front surface of the electric furnace to prevent thermal deformation of the door plate portion 13.

The upper door member 10 is prevented from being deformed by heat due to an increase in air cooling effect and rigidity of the rib portion 12.

The rib portion 12 includes a rim 12a protruding along the outer periphery of the upper door member 10;

A plurality of lateral ribs (12b) projected to be horizontally spaced apart from the upper door member (10) in the frame rib (12a);

And a plurality of longitudinal ribs 12c which are vertically spaced and protruded from the upper door member 10 in the frame rib 12a. The longitudinal ribs 12c may be disposed between the lateral ribs 12b and between the lateral ribs 12b and the rim ribs 12a.

The rib portion 12 secures the rigidity of the door plate portion 13 by the rim 12a, the lateral rib 12b and the longitudinal rib 12c to prevent deformation in various directions.

The present invention has an effect of preventing leakage of slag during the steelmaking operation of an electric furnace to reduce heat loss due to slag discharge, increase the efficiency of arc heat by forming foam slag, and recover the molten metal in molten slag to increase the recovery rate of molten steel .

According to the present invention, the durability of the door for opening and closing the slag outlet 1c is increased, and the slag outlet 1c can be stably opened and closed for a long period of time, and the maintenance cost is reduced.

It will be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the present invention.

1: electric furnace body 10: upper door member
11: cooling water flow path 12: rib portion
20: upper door movement device 21: door operation wire
22: upper door operating part 23: door operation guide roll member
30: Lower door member 31: High hardness coating layer
40: Lower door movement device 41: Operation frame part
42: lower door operating part 50: heat sink member
51: heat sink part 52: panel rotating part
60: first guide plate member 61: first outlet
62: support part 70: second guide plate member
71: second outlet 80: guide roller member

Claims (9)

delete An electric furnace main body having a space portion in which scrap is charged and melted and a molten steel discharge port for discharging molten steel and a slag discharge port for discharging slag separately from the molten steel discharge port;
An upper door member for opening and closing an upper portion of the slag outlet;
An upper door movement device for moving the upper door member up and down;
A lower door member for opening and closing a lower portion of the slag outlet;
A lower door moving device for moving the slag outlet upward and downward; And
And a heat sink member spaced apart from a lower portion of the lower door mobile device,
Wherein the heat sink member is mounted obliquely and the tilted end side is opened. An electric furnace main body having a space portion in which scrap is charged and melted and a molten steel discharge port for discharging molten steel and a slag discharge port for discharging slag separately from the molten steel discharge port;
An upper door member for opening and closing an upper portion of the slag outlet;
An upper door movement device for moving the upper door member up and down;
A lower door member for opening and closing a lower portion of the slag outlet;
A lower door moving device for moving the slag outlet upward and downward; And
And a heat sink member spaced apart from a lower portion of the lower door mobile device,
The heat sink member may include:
A heat radiating plate part rotatably connected to the support at one end thereof; And
And a panel rotating part for rotating the heat sink part. The method of claim 3,
The panel rotation unit includes:
A connection wire connected to the other end side of the heat sink part;
A take-up reel for winding and unwinding the connecting wire by forward and reverse rotation by a motor; And
And a guide roll which is rotatably installed to guide the connecting wire to the take-up reel and to move the other end side of the heat radiating plate portion up and down while the connecting wire is wound or unwound. The method according to claim 2 or 3,
Wherein a high hardness coating layer is formed on the front and rear surfaces of the lower door member, respectively. The method according to claim 2 or 3,
A first guide plate disposed on a rear surface side of the lower door member disposed toward the inside of the electric furnace and guiding upward and downward movement of the lower door member and the upper door member and having a first discharge port for discharging slag, absence; And
And a second guide plate member disposed on a front surface side of the lower door member and guiding the upward and downward movement of the lower door member and the upper door member and having a second discharge port for discharging the slag,
Wherein a plurality of support portions spaced apart from a lower portion of the first guide plate member are protruded and a space is formed between the plurality of support portions. The method according to claim 2 or 3,
Wherein the upper door member has a cooling water flow path formed therein. An electric furnace main body having a space portion in which scrap is charged and melted and a molten steel discharge port for discharging molten steel and a slag discharge port for discharging slag separately from the molten steel discharge port;
An upper door member for opening and closing an upper portion of the slag outlet;
An upper door movement device for moving the upper door member up and down;
A lower door member for opening and closing a lower portion of the slag outlet;
A lower door moving device for moving the slag outlet upward and downward; And
And a heat sink member spaced apart from a lower portion of the lower door mobile device,
Wherein the upper door member comprises:
A door plate portion for opening and closing an upper portion of the slag outlet; And
And a plurality of ribs protruding from the door plate toward the outside of the electric furnace. The method of claim 8,
The rib portion
A frame rib protruding along the outer circumference of the upper door member;
A plurality of lateral ribs protruding from the edge ribs so as to be laterally spaced apart from the upper door member; And
And a plurality of vertical ribs protruding from the upper edge of the upper door member so as to be vertically spaced apart from each other.

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