JP3102255B2 - Graphite electrode cooling device for arc furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for cooling a graphite electrode of an arc heating furnace.

[0002]

2. Description of the Related Art In a steelmaking arc furnace, a graphite electrode is generally used as an electrode for generating an arc. The tip of the graphite electrode is consumed by the arc heat, and at the same time, is exposed to a high-temperature atmosphere in the furnace, and the side surface of the electrode is oxidized and consumed. In order to reduce this oxidative consumption, a method has been proposed in which the electrode is cooled by spraying water onto the electrode to suppress surface oxidation.However, this method does not provide sufficient cooling, so that a flowing water film is formed on the surface of the electrode. A method of forming and cooling is proposed in Japanese Utility Model Publication No. 2-1838.

As shown in FIG. 8, an annular cooling liquid supply nozzle tube 4 is provided below an electrode holder 3 so as to surround the outer periphery of the electrode 2, and the surface of the electrode 2 protruding above the furnace lid 1 is provided. And a pressurized air injection nozzle tube 5 is provided around the electrode 2 insertion position in the furnace to blow off the cooling water flowing down so that the flowing water does not enter the furnace. Things.

[0004]

The above-mentioned flowing water type cooling device is provided immediately below an electrode holder or above a furnace lid, and sprays water onto an electrode surface in an outer portion of an arc furnace to discharge the electrode. Water is allowed to flow down on the surface of the electrode to cool the electrode. However, the contact area of the cooling water is 1 to 1.5 m from the electrode holder, which is insufficient for cooling the side portion of the heated graphite electrode in the furnace during normal operation. In addition, since the cooling water scatters around during the jetting and flowing down, there is a problem that a larger amount of cooling water is required for the amount of the scattered water. SUMMARY OF THE INVENTION An object of the present invention is to provide a graphite electrode cooling device capable of efficiently cooling an electrode part inserted into a furnace and suppressing its oxidative consumption.

[0005]

An arc according to the first invention is provided.
Graphite electrode cooling device of the heating furnace, a tubular body surrounding the sides all around the graphite electrodes, from the bottom of the electrode holder to the furnace, provided through the furnace lid electrode hole, the tubular body and the graphite electrode The present invention is characterized by having a spraying device for discharging a cooling medium therebetween. Graphite electrode of arc heating furnace according to the second invention
Cooling apparatus further the tubular body, it is characterized in that it is divided structure in the longitudinal direction. Third invention
The graphite electrode cooling device of the arc heating furnace according to
JP bottom of inner diameter, the smaller Ikoto than the inner diameter of the other portions of the
It is a sign .

[0006]

In the first aspect , the graphite electrode is an electrode holder .
The entire circumference of the side of the furnace from the lower part of the furnace to the inside of the furnace is surrounded by a cylindrical body.
As a result, the graphite electrode is not exposed to a flame that blows up from the furnace through the electrode hole and can also shield radiant heat from molten steel in the furnace, so that the graphite electrode is not overheated and is not easily oxidized.

Furthermore, the gap between the tubular body and the graphite electrode cooling medium such as liquid or inert gas such as water flows out from the spraying device. No guide role with respect to the cooling medium tubular body flows down, and it is possible to suppress the scattering of the cooling medium. For this reason, since the electrode surface is covered to a lower part by the cooling medium, the graphite electrode is not overheated and oxidation consumption is reduced.

In the second aspect of the present invention, the cylindrical body has a structure that is divided in the longitudinal direction, so that the device can be easily attached and detached, thereby greatly improving workability.

In the third aspect of the present invention, since the inner diameter of the lower part of the cylindrical body is smaller than the inner diameter of the other part, the cooling medium ejected from the lower end of the cylindrical body is restricted by the cylindrical body, and the electrode side surface is formed. Down along . Therefore, a scattering loss amount of the cooling medium can little without suppressing Rukoto, can be coated uniformly and wide electrode surface area electrodes entire periphery with a small amount of the cooling medium ejection amount. Further, it is possible to prevent adverse effect of lowering the furnace temperature since the cooling medium amount decreases splashing.

[0010]

FIG. 1 is a view showing an embodiment in which a cooling device of the present invention is mounted in a DC arc furnace. Where 1
Is a furnace lid, 2 is a graphite electrode (single electrode), 3 is an electrode holder, 6 is a furnace body, 7 is a heat melting material (generally, scrap), 10 is a cylindrical cooler, and 13 is charged in the furnace. This is the upper end of the heated melting material 7. The furnace lid 1 is covered on the upper part of the furnace body 6, and an electrode hole 17 for inserting the graphite electrode 2 into the furnace is provided in the center of the furnace lid 6. Graphite electrode 2
The upper part is held by the holder 3 and is inserted into the furnace through the electrode hole 17 by a holder elevating means (not shown) or pulled up from the furnace.

In the above-described arc furnace, the cylindrical cooler 10 surrounding the graphite electrode 2 from immediately below the holder 3 to the vicinity of the upper end 13 of the heated and molten material 7 in the furnace is provided with the holder 3.
Or provided and fixed to the arm 20. In FIG.
Although the length of the cylindrical cooler 10 is set to the length to the upper end of the heated molten material, if the cylindrical cooler 10 does not come into contact with the molten material, it may be further lowered.
The tubular cooler 10 may be extended. The cylindrical cooler 10
A hollow cylindrical panel made of copper, iron or the like has a water-cooled structure inside, and examples thereof are as follows.

FIG. 2 shows a first embodiment of the present invention, which is a hollow cylindrical body, and a through hole 18 at the center thereof is a through hole for the graphite electrode 2. A baffle plate 10 is provided inside the cylindrical body so that cooling water flows meandering in the vertical direction of the panel.
c is provided in plurality. The cooling water is supplied to the inlet pipe 10.
a, and is drained from the drain pipe 10b. FIG. 3 shows the second
In this embodiment, a cylindrical cooling device 10 is constructed by attaching one pipe 10d through which cooling water flows in a meandering manner around the outer periphery of a cylindrical body 10e. As in the first embodiment, the cooling water enters through the inlet pipe 10a and is drained from the drain pipe 10b.

FIG. 4 shows a third embodiment, in which a pipe 10d through which cooling water flows is wound into a cylindrical shape, and a cylindrical cylindrical cooler 10 is formed.
The center hole is a through hole for the graphite electrode.
FIG. 5 shows a fourth embodiment, in which a cylindrical cylindrical cooler 10 is provided.
Is divided into two in the longitudinal direction, and the work of attaching and detaching to the graphite electrode 2 becomes remarkably easy. In this embodiment, since the cylindrical cooler 10 (first embodiment) shown in FIG. 2 is divided into two, the inlet pipe 10a and the drain pipe 10b of the cooling water are also each divided into two.

In the present invention, the above-mentioned cylindrical cooler 10 is placed directly below the graphite holder 3 from the upper end 13 of the heated and molten material 7 in the furnace.
Since it surrounds the area up to the vicinity, the flame blowing from the electrode hole and the radiant heat in the furnace are shut off.

FIGS. 6 and 7 show fifth and sixth embodiments in which the inner diameter of the lower part of the cylindrical body 10 'is smaller than the inner diameter of the other parts. FIG. 6 shows a cylinder 1
Water as a cooling medium is poured into the gap 12 between the 0 'and the graphite electrode 2 to form a flowing water film 16 on the outer peripheral side surface of the graphite electrode 2. The flow of the cooling water into the gap 12 is performed by an annular water injection pipe 15 provided so as to surround the graphite electrode 2 at the upper end of the cylindrical body 10 ′. A plurality of water injection nozzle holes are provided inside the annular water injection pipe 15 (electrode side), and water is injected from the water injection nozzle holes toward the gap 12 between the cylindrical body 10 ′ and the graphite electrode 2. Since the inside diameter of the lower part of the cylindrical body 10 'is configured to be small, the cooling water is throttled by the cylindrical body 10' and flows down along the electrode side surface. Therefore, a scattering loss amount of the cooling water can little without suppressing Rukoto could cover a uniform and wide electrode surface area electrodes entire periphery with a small amount of the cooling water.

Thus, the flame of the cylindrical body 10 'blowing up from the electrode hole and the radiant heat from the furnace are cut off.
The flowing water film 16 flowing down the outer peripheral side surface of the graphite electrode 2 is
The graphite electrode 2 below 0 'is cooled. Therefore, in addition to the range in which the cylindrical body 10 'from the lower portion of the electrode holder 3 to the vicinity of the upper surface of the heated melting material in the furnace surrounds the electrode side surface, the oxidative consumption of the graphite electrode below the electrode side is reduced.

FIG. 7 shows an embodiment in which a water injection pipe 15a is inserted from above with a wide gap, and an annular water injection pipe 15 is provided so as to surround the graphite electrode 2 below the cylindrical body 10 '. Here, as in FIG.
A plurality of water injection nozzle holes are provided on the inner side (electrode side), and water is injected from the water injection nozzle holes toward the gap 12 between the cylindrical body 10 ′ and the graphite electrode 2. However, in this case, it is necessary to take measures against heat when the water in the annular water injection pipe 15 is stopped.
In FIG. 7, it is provided and protected on the small diameter portion at the lower part of the cylindrical body 10 '.

In the embodiment shown in FIGS. 6 and 7,
Since the inner diameter of the lower portion of the cylindrical body 10 'is formed smaller than the inner diameter of the other portions, thereby, flowing water film 16 flowing down the outer peripheral surface of the graphite electrode 2 is thinner and uniform coating on the outer peripheral side surface Is formed, the flowing water film 16 can reach farther from the lower end of the cylindrical body 10 ′. Further, the amount of leakage and scattering in the furnace can be reduced.

[0019]

According to the present invention , the side surface of the graphite electrode is surrounded.
A cylindrical body is arranged from below the electrode holder to near the upper end of the heated melting material, and a cooling medium is provided in a gap between the cylindrical body and the graphite electrode.
Since the is flow, it can block radiation heat from the blown-up flame and the furnace from the electrode hole, the oxidation loss of graphite electrodes because graphite electrodes can also be cooled can be greatly reduced compared with the conventional.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of an embodiment in which a cooling device of the present invention is mounted on a graphite electrode.

FIG. 2 is a view showing a first embodiment of a cylindrical cooler .

FIG. 3 is a view showing a second embodiment of the cylindrical cooler ;

FIG. 4 is a view showing a third embodiment of the cylindrical cooler ;

FIG. 5 is a diagram showing an example of a cylindrical cooler divided into two in the longitudinal direction.

FIG. 6 is a view showing an embodiment of a cooling device in which an annular water injection pipe is arranged at an upper end of a cooling device of the present invention and water is injected into a gap between the cooling device and an electrode.

The annular water injection pipe placed under side of the cooling apparatus of the present invention; FIG device, the gap between the cooling device and the electrode is a diagram showing an embodiment of a cooling device for water injection.

FIG. 8 is a diagram showing a cooling device according to the related art.

[Explanation of symbols]

2 Graphite electrode 3 Electrode holder 7 Heat melting material 10 Cylindrical cooler 10 'Cylindrical body 12 Gap 15 Annular water injection pipe 16 Flowing film

Claims (3)

(57) [Claims] 1. A cylindrical body sides surrounding the entire circumference of the graphite electrodes, from the bottom of the electrode holder to the furnace, provided through the furnace lid electrode hole, the cooling medium between the cylindrical body and the graphite electrode Leaked
A graphite electrode cooling device for an arc heating furnace, comprising a spraying device for spraying . 2. A structure in which the cylindrical body is divided in a longitudinal direction.
The apparatus for cooling a graphite electrode of an arc heating furnace according to claim 1, wherein 3. An inner diameter of a lower portion of the cylindrical body is different from that of another portion.
The graphite electrode cooling device for an arc heating furnace according to claim 1 or 2, wherein the device is smaller than an inner diameter .