JPH11144863A - Water cooling of lf electrode and apparatus for receiving cooling water to be used for water cooling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress LF electrode consumption and prevent possible steam explosion. SOLUTION: After a ladle is transported from the position under a carbon electrode 15 on completion of metal refining, a cooling water receiving member 24 is positioned under the carbon electrode and cooling water is sprayed to the upper part of the carbon electrode to soak the electrode along the electrode surface and cool the electrode. The dripped and scattered cooling water is received by the cooling water receiving member 24 and discharged out of the LF operation system. Then, cooling water spraying is stopped before a next ladle is carried in and the cooling water receiving member is evacuated out of the position under the carbon electrode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cooling water of an LF electrode and a cooling water receiving apparatus used for the method, and more particularly to a method and an apparatus for reducing the consumption of carbon electrodes and eliminating the risk of steam explosion.

[0002]

2. Description of the Related Art In recent years, from the viewpoint of quality and productivity, the out-of-pile smelting method has tended to be adopted not only in the field of special steel but also in some fields of ordinary steel. For example, iron scraps are melted in an electric furnace, received by a ladle, and the ladle is transported to the LF and
A method of refining steel having a desired composition with F is known.

Usually, in this type of LF, a plurality of (mostly three) carbon electrodes supported by electrode clamps are inserted into a furnace lid, while rails are laid on a floor surface, and a ladle is moved to a position below the electrodes. A structure is adopted in which the furnace lid is lowered by an elevating mechanism to cover the ladle, the electrodes are inserted into the ladle, and refining is performed by energization.

[0004]

However, in such LF, a carbon electrode is used as an electrode, and this electrode becomes a high temperature of 1600 ° C. or more during the refining operation, so that electrode consumption is severe and electrode cost is extremely increased. there were.

On the other hand, in the operation using LF, there is a waiting time after refining until the next steel receiving pan is carried in below the electrode. Therefore, a method of using the waiting time to reduce the electrode consumption by cooling the carbon electrode with water is proposed. However, if the cooling water after electrode water cooling is dropped or scattered and falls on the floor, high-temperature molten steel scatters during operation and comes into contact with water on the floor, and there is a concern about the danger of steam explosion. From the viewpoint of safe operation, it is difficult to adopt water cooling of the electrodes.

The present invention has been made in view of the above problems, and has as its object to provide a water cooling method for an LF electrode, which can reduce electrode consumption, and surely prevent a feared steam explosion to ensure safe operation. And

[0007]

Therefore, the L according to the present invention is described.
The water cooling method of the F electrode is such that, during the waiting time between the refining operations in the LF, the plurality of carbon electrodes inserted into the furnace lid are cooled with water. The cooling water receiving member is positioned below the carbon electrode, and the cooling water is sprayed on the upper portion of the carbon electrode to cool the carbon electrode along the surface of the cooling water to cool the carbon electrode, and the cooling water drips and scatters. Received by the cooling water receiving member, drained out of the LF operation system, stopped spraying the cooling water before carrying in the next ladle, and retracted the cooling water receiving member from the position below the carbon electrode. It is characterized by the following.

One of the features of the present invention is that the cooling water receiving member is moved between the position below the carbon electrode and the retracted position, and receives and discharges the cooling water dropped and scattered from the carbon electrode. This ensures that the cooling water does not fall on the floor, and the danger of steam explosion can be reliably eliminated. In addition, since the carbon electrode is water-cooled by spraying cooling water, electrode consumption can be significantly reduced, and significant cost reduction can be achieved.

[0009] The cooling temperature of the carbon electrode is from 600 ° C to 65 ° C.
A temperature range of 0 ° C. is appropriate. This is because if the temperature is cooled to 600 ° C. or lower, the carbon electrode may be broken and scattered at the start of the next refining operation.

The cooling water receiving member may be slid forward and backward between the position below the carbon electrode and the retracted position, or may be turned. However, when turning, there is a possibility of interfering with the LF.

Although the cooling water receiving member may be provided corresponding to each of the plurality of carbon electrodes, the moving mechanism may be complicated. Therefore, it is preferable to use a cooling water receiving member having a sufficient area to receive the cooling water dropped and scattered from the plurality of carbon electrodes.

Further, the cooling water receiving device itself used in the above-described water cooling method is also new and novel. . Therefore, according to the present invention, there is provided a cooling water receiving device which receives cooling water dropped and scattered when water-cooling a plurality of carbon electrodes of an LF, and discharges the cooling water to the outside of the LF operation system. A guide member extending to a position and not interfering with the ladle to be carried in and out and the LF during operation, a movable carriage slidably supported by the guide member, and a drive mechanism for sliding the movable carriage forward and backward. Provided at the tip of the moving trolley, has a sufficient area to receive cooling water dripped and scattered from a plurality of carbon electrodes, and is located at a position below the carbon electrode when the moving trolley moves forward, A cooling water receiving member located at a position that does not interfere with the ladle carried in and out at the time of retreat and the LF in operation, and a drainage channel connected to the bottom of the cooling water receiving member and extending outside the LF operation system. It was example it is possible to provide a receiving cooling water systems used in water cooled LF electrode characterized by.

Although a guide rail can be used as the guide member, another member such as a cylindrical member may be used. The movable trolley may have any structure, but it is necessary that the movable trolley be slidably supported by at least the guide member.

Although the cooling water receiving member may have any shape, it is preferable that the cooling water receiving member is formed in a constricted state in order to drain the cooling water. In addition, slag and the like during refining adhere to the carbon electrode, and there is a possibility that slag and pieces of the electrode may fall during water cooling and clog the drainage channel. Therefore, it is preferable to provide a sheet-shaped filter in the middle of the cooling water receiving member in the height direction to remove slag and pieces of the electrode.

The drainage channel may be structured to extend and contract in a bellows type or a slide type. The drainage channel extends along the guide member and has an open upper surface, and the rear end is slidably inserted into the drainage groove. And a drain pipe whose tip is connected to the bottom of the cooling water receiving member.

[0016]

According to the present invention, the carbon electrode is cooled by spraying cooling water on the carbon electrode by utilizing the waiting time during the smelting operation. Cost reduction can be achieved.

Further, the cooling water receiving member is moved between the lower position of the carbon electrode and the retracted position to receive the cooling water dropped and scattered from the carbon electrode and to drain the cooling water out of the system. Cooling water has not fallen in
The danger of steam explosion during the refining operation can be reliably eliminated, and the safety of the operation can be guaranteed.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to specific examples shown in the drawings. 1 to 7 show a preferred embodiment of a method for water-cooling an LF electrode according to the present invention. In the figure, a plurality of columns 10... Are erected on a floor surface F, and a furnace column 11 is supported on a suitable column 10 so as to be able to move up and down, and an elevating device (FIG. (Not shown).

A work table 12 is provided on the side of the furnace lid 11, a sub-material input device (not shown) is disposed on the work table 12, and a rail 16 is provided on the floor F. A rail 16 extends between the lower part of the furnace lid 11 and the outside, for example, between the electric furnace, and the rails 16 guide the running of the ladle 13.

Further, an electrode clamp 14 is provided above the furnace lid 11 to clamp three carbon electrodes 15..., Which are inserted into the furnace lid 11. An annular pipe 70 is provided in the vicinity of the electrode clamp 14 of each of the three carbon electrodes 15..., And a plurality of nozzles 71 are attached to the annular pipe 70 at appropriate intervals. 70 is connected to a cooling water supply pipe 72, and the cooling water is supplied to the carbon electrode 15.
Are sprayed in the form of a spray, are adapted along the entire outer peripheral surface of the electrode, and are cooled with water.

On the other hand, a cooling water receiving device 20 is installed in the middle stage of the work table 12. In this cooling water receiving device 20, a pair of guide rails (guide members) 21, 21 made of H-shaped steel are attached to the middle stage of the work table 12 so as to extend in a direction toward the electrode lower position and not project from the work table 12. On the other hand, wheels 23 are supported on the movable cart 24 at appropriate intervals in the front-rear direction, and the wheels 23 are slidably supported by the guide rails 21.

The movable carriage 22 has a substantially closed cross section.
At its tip, a cooling water receiving member 24 is attached,
When the movable carriage 22 moves to the tip of the guide rails 21, the cooling water receiving member 24 is located at a position below the electrodes,
When the movable carriage 22 returns to the rear end of the guide rails 21, the ladle 13, the furnace lid 11, and the electrode 15 that are carried in and out come to a position where they do not interfere with the ladle 13, the furnace lid 11, and the electrodes 15.

A drive mechanism 30 for sliding the movable carriage 22 is provided below the middle stage of the work table 12.
In the drive mechanism 30, a rack gear 31 is attached to the lower surface of the movable carriage 22 so as to extend in the longitudinal direction, and a pinion gear 332 meshes with the rack gear 31, and a driving force transmission gear 33 is coaxially mounted on the pinion gear 32. The driving force transmission gear 33 is attached and connected to a gear 35 of a rotating shaft of a driving motor 35 by a chain 34. A support roller 37 is coaxially mounted on the pinion gear 32 to support the lower surface of the movable carriage 22.

On the other hand, the cooling water receiving member 24 has a flat rectangular shape and a constricted shape having a sufficient area for dropping and scattering from the three carbon electrodes 15... 50 are provided to remove falling objects falling from the carbon electrodes 15... During water cooling.

A drain 40 is connected to the bottom of the cooling water receiving member 24, and the other end of the drain 40 extends to a water treatment groove outside the system. The drainage channel 40 mainly includes a drainage pipe 41 and a drainage groove 42 having an open upper surface.
The drain groove 42 extends along the guide rail 21 on the side of the guide rail 21 and is connected to the water treatment groove by a drain pipe (not shown) at the end side.

On the other hand, the drain pipe 41 is mounted above the movable carriage 22, the front end is connected to the outside of the cooling water receiving member 24, and the rear end is bent downward and slidably inserted into the drain groove 42. Have been.

For example, when scrap iron or the like is melted in an electric furnace and steel is received by a ladle 13, the ladle 13
1 is carried down. When the ladle 13 stops at a predetermined position, the furnace lid 11 is lowered and put on the ladle 13, energized to the carbon electrodes 15,..., And auxiliary materials are charged to perform refining. When the refining is completed, energization of the carbon electrodes 15 is stopped, the furnace lid 11 is raised, the ladle 13 is carried out, and the next ladle 13 is carried in. This waiting time is approximately 10 to 12 minutes.

Then, when the ladle 13 after the refining is carried out, the driving mechanism 30 slides the movable carriage 22 forward, and when the cooling water receiving member 24 is located at the lower position of the electrode, the circular pipe 70 Cooling water is supplied and the nozzle 71
··· Cooling water is sprayed from the spraying, and the cooling water is adapted along the outer surface of the carbon electrodes 15..., And the carbon electrodes 15.
Cool to a temperature of 50 ° C.

The cooling water dropped and scattered from the carbon electrodes 15... Is reliably received by the lower cooling water receiving member 24.
The water is drained to the water treatment ditch via the drain 40.

When a predetermined time has elapsed, the supply of the cooling water is stopped, and the driving mechanism 30 moves the movable carriage 22.
After the ladle is retracted to a position where it does not interfere with the ladle 13, etc., the next ladle 13 is carried in, and the refining operation is started.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an LF facility to which a water cooling method according to the present invention is applied.

FIG. 2 is a schematic plan view showing a cooling water receiving device used for water cooling of an LF electrode according to the present invention.

FIG. 3 is a schematic side view showing the configuration of the cooling water receiving device.

FIG. 4 is a front configuration diagram showing the cooling water receiving device.

FIG. 5 is a guide rail in the cooling water receiving device,
FIG. 2 is a configuration diagram illustrating a movable trolley and a drive mechanism.

FIG. 6 is a diagram showing a relationship between a carbon electrode and a cooling water receiving member.

FIG. 7 is a perspective view showing supply of cooling water to a carbon electrode.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Furnace lid 15 Carbon electrode 20 Cooling water receiving device 21 Guide rail (guide member) 22 Moving trolley 24 Cooling water receiving member 30 Drive mechanism 40 Drainage channel 41 Drainage pipe 42 Drainage groove 50 Filter 70 Ring pipe 71 Nozzle

Claims (7)

[Claims] When cooling a plurality of carbon electrodes inserted into a furnace lid during a waiting time between refining operations in an LF, a ladle after refining is carried out from a position below the carbon electrodes and then cooled. A water receiving member is positioned below the carbon electrode, and cooling water is sprayed onto the upper portion of the carbon electrode to cool the carbon electrode by accustoming the cooling water along the surface of the electrode, and to cool the carbon electrode by dropping and scattering the cooling water. It is received by the cooling water receiving member, drained out of the LF operation system, stops spraying the cooling water before carrying in the next ladle, and retracts the cooling water receiving member from the position below the carbon electrode. Characteristic water cooling method for LF electrodes. 2. The water cooling method for an LF electrode according to claim 1, wherein the cooling water receiving member is slid forward or backward or swiveled between a position below the carbon electrode and a retracted position. 3. The water cooling method for an LF electrode according to claim 1, wherein a cooling water receiving member having an area sufficient to receive the cooling water dropped and scattered from the plurality of carbon electrodes is used. 4. The method according to claim 1, wherein the carbon electrode is heated to a temperature of 600 to 650 ° C.
2. The LF according to claim 1, wherein the LF is cooled to a temperature range of
Water cooling method for electrodes. 5. A cooling water receiving device for receiving cooling water dropped and scattered when water-cooling a plurality of carbon electrodes of the LF and discharging the cooling water to the outside of the LF operation system, wherein the cooling water receiving device is directed from a side of the LF to a position below the carbon electrodes. And a guide member extending to a position that does not interfere with the ladle to be loaded and unloaded and the LF during operation, a movable carriage slidably supported by the guide member, a drive mechanism for sliding the movable carriage forward and backward, and the movable carriage Is provided at the tip of the vehicle, has a sufficient area to receive cooling water dripped and scattered from the plurality of carbon electrodes, is positioned below the carbon electrodes when the moving vehicle moves forward, and is loaded when the moving vehicle moves backward. A cooling water receiving member positioned so as not to interfere with the ladle to be carried out and the LF during operation; and a drainage channel connected to the bottom of the cooling water receiving member and extending outside the LF operation system. DOO coolant receiving device for use in water cooled LF electrode characterized by. 6. A drain groove extending along the guide member and having an open upper surface, a rear end slidably inserted into the drain groove, and a front end formed at a bottom of a cooling water receiving member. 6. A cooling water receiving device for use in water cooling of an LF electrode according to claim 5, comprising a drain pipe connected to the cooling water receiving device. 7. The cooling water receiving device according to claim 5, wherein the cooling water receiving member has a constricted shape, and a sheet-like filter is provided in the middle of the height direction.