JP3002769B2 - Electric furnace conductor arm - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductor arm of an electric furnace to which a water-cooled cable is connected at one end and an electrode holder is connected at the other end, and power is supplied from the water-cooled cable to an electrode mounted on the electrode holder.

[0002]

2. Description of the Related Art Conventionally, various electric furnaces have been widely used for producing steel such as pig iron and scrap iron. In this electric furnace, the tip of an electrode such as a self-firing electrode is embedded in raw materials such as pig iron, scrap iron, carbon material, and a solvent material (or flux) such as limestone charged in the electric furnace. When the electrodes are energized, Joule heat is generated based on the energized current and the electric resistance of the raw materials, thereby melting the raw materials. At the start and end of the steelmaking operation of the electric furnace, the electrode is usually placed on the side of the electric furnace by a winch so that the electrode enters and exits through an electrode insertion hole formed in the furnace lid of the electric furnace having a large outer diameter. A conductor arm (or simply, a conductor arm) of an electric furnace laid via an insulator on the upper surface of an electrode column which is provided so as to be vertically movable by a lifting means such as
At one end via an electrode holder (or an electrode clamp). In order to supply power to the electrodes, a flexible electric wire having a copper wire surface coated with an insulator is attached to the other end of the conductor arm, and the other end of the flexible electric wire is connected to an electric furnace. Connected to a power supply such as a power transformer. Note that a so-called water-cooled cable is usually used for the flexible electric wire, which generates heat during power supply during a steelmaking operation and is cooled through cooling water.

However, in the conventional conductor arm, the electric power supplied from the power supply via the water-cooled cable is efficiently transmitted to the electrode holder, and the cooling water formed inside the conductor arm for preventing heat generation of the conductor arm. For the purpose of improving the sealing property (or water tightness) of the cooling water supplied to the passage, a copper plate or a copper alloy plate is formed into a substantially rectangular frame shape (or box shape in cross section) of the conductor arm. Welded. However, it is difficult to weld a copper plate or a copper alloy plate, and furthermore, it is necessary to reduce the weight of the conductor arm due to the necessity of raising and lowering the electrodes. Alternatively, there has been a problem that only those having an outer diameter (or width) of about 160 mm can be manufactured using a copper alloy plate. For this reason,
Since the electric resistance R obtained by the following equations (1) and (2) increases in inverse proportion to the cross-sectional area S of the conductor arm, a large power loss occurs and heat generation of the conductor arm is large, so-called running cost increases. Had problems. R = ρ _T · L / S (1) ρ _T = ρ ₂₀ · [1 + α ₂₀ (T−t ₂₀ )] (2) R: electrical resistance (Ω) L: length of conductor arm (m) S: cross-sectional area of conductor arm (m ² ) T: temperature of conductor arm when energized (° C.) t ₂₀ : non-energized Conductor arm temperature (20 ° C) ρ _T : resistivity (Ω at the time of temperature T ° C) of the conductive arm
· M) ρ ₂₀ : resistivity of the conductor arm at 20 ° C (Ω · m) α ₂₀ : temperature coefficient of resistance of the conductor arm at 20 ° C (° C ^-1 )

In order to solve this problem, a method has been proposed in which aluminum is used as the material of the conductor arm. In this method, when copper is used for the conductor arm, ρ ₂₀ = 1.69 and α ₂₀ =
On the other hand, when aluminum is used for the conductor arm, ρ ₂₀ = 2.
62, since α ₂₀ = 0.0039, the temperature coefficient of resistance α
₂₀ is the same, but there is a large difference in the resistivity at 20 ° C. Further, while the specific gravity of copper is 8.945, the specific gravity of aluminum is 2.69, which is about ３ of the specific gravity of copper. .3
Although the electric resistance R per unit volume increases due to the small size, the cross-sectional area S can be increased correspondingly by utilizing the low specific gravity. In this case, the electric resistance R can be reduced to greatly reduce the amount of electric power used. Furthermore, since mechanical strength such as bending strength of aluminum is higher than mechanical strength such as bending strength of copper, conventionally, a copper or copper alloy conductor arm has a copper plate or a copper alloy plate on one side thereof. Although it was necessary to weld a reinforcing material such as an iron plate having an area approximately equal to or greater than that, it can be made unnecessary, so that the weight of the reinforcing material is reduced,
Further, the running cost can be reduced.

[0005]

However, since the water-cooled cable and the electrode holder are made of copper or a copper alloy, it is inevitable to use the good conductivity of the copper or the copper alloy and to take the production workability into consideration. The joint surface with the arm (that is, the electrical contact or terminal for making an electrical connection) is also made of copper or a copper alloy. However, since the conductor arm is made of aluminum, even if the conductor arm, the water-cooled cable, the electrode holder, etc. Even if the joining surface is machined into a smooth shape and connected (or contacted), it cannot be completely contacted, so that a cross-sectional area S required for a large-capacity electric power to be supplied cannot be obtained. In addition, there is a problem that contact resistance occurs between the contacted joining surfaces, heat generation and power loss occur, and running costs increase. Further, aluminum is easily oxidized and corroded, and the electrical resistance R of the aluminum oxide film formed on the surface by this oxidation is large.
Further, there is a problem that a calorific value and a power loss occur, and a running cost increases. Therefore, in order to solve this problem, the present inventors have tried a method of eliminating poor contact between the joint surfaces by plating copper on each joint surface of the aluminum conductor arm. As described above, since the cross-sectional area S of the conductor arm is increased for the purpose of reducing the electric resistance R, the overall shape becomes large, it is difficult to put the conductor arm into the plating tank, and the productivity is extremely poor. Was found. Therefore, a method of bonding a copper plate to each joint surface of an aluminum conductor arm via melted aluminum or a method of pressing and bonding a copper plate in the above-described state has been tried. Has been found to be extremely difficult to do.

The present invention has been made in view of such circumstances, and it is possible to easily coat copper on each joint surface for electrically connecting an aluminum conductor arm to a water-cooled cable or an electrode holder, As a result, it is possible to reduce contact resistance and the like due to poor contact between the joint surfaces, obtain good contact with a water-cooled cable or an electrode holder, and significantly reduce running costs. The purpose is to provide an arm.

[0007]

According to the present invention, there is provided a semiconductor device comprising:
The conductor arm of the electric furnace described above is a conductor arm of an electric furnace that has a water-cooled cable at one end and an electrode holder connected to the other end, and supplies power to the electrode mounted on the electrode holder from the water-cooled cable. The conductor arm is made of aluminum, and copper powder is sprayed on the joint surface of the conductor arm with the electrode holder and the joint surface of the water-cooled cable. Further, in the conductor arm of the electric furnace according to the second aspect, in the conductor arm of the electric furnace according to the first aspect, each of the joining surfaces is ground into a flat surface after the copper powder is sprayed thickly. . The conductor arm of the electric furnace according to claim 3 is the conductor arm of the electric furnace according to claim 1 or 2, wherein the conductor arm has a box-shaped cross section, has sufficient strength, and is internally water-cooled. ing.

The conductor arm of the electric furnace of the present invention can be used in an electric furnace such as a DC arc furnace such as a vacuum arc furnace or a plasma arc furnace or an AC arc furnace such as a three-phase AC furnace. The term "made of aluminum" refers to pure aluminum or aluminum alloy having good conductivity. As the copper powder, a thermal spraying method in which a copper powder in a molten state or a state close to the molten state is sprayed on a joining surface of a conductor arm made of aluminum to form a coating is applied. Further, as the thermal spraying method, there is a so-called plasma spraying method in which a copper powder is heated and accelerated by using a plasma jet generated by a plasma spraying gun and sprayed onto a bonding surface in a molten state or a state close to the molten state to form a coating. . By applying this thermal spraying method, in particular, plasma thermal spraying method, as described above, the plasma generated by the gas discharge is ejected from the nozzle, and the copper powder is sprayed with a high-temperature and high-speed gas stream (or plasma jet). Can be easily coated (or called electrical contact) on the joint surface
Can be formed. Note that working gases applied to the plasma spraying method include argon (Ar), helium (He), nitrogen (N ₂ ), hydrogen (H ₂ ), and the like.
Examples of a method for making the surface of the copper powder sprayed on each joint surface of the conductor arm of the electric furnace a flat surface (or a smooth surface) include a machining method such as a grinding method and a cutting method. Further, the thickness (t _Cu ) of the copper powder (or referred to as an electrical contact or terminal) which has been smoothed after being sprayed on each joint surface of the conductor arm is not particularly limited, but is, for example, 1 mm ≦ t _Cu ≦ 3 mm, preferably 1 mm ≦ t
Preferably, _Cu ≦ 2 mm. If the thickness of the smoothed copper powder is less than 1 mm after being sprayed on each joint surface, there is a possibility that electrolytic corrosion may occur, and after being sprayed on each joint surface,
When the thickness of the smoothed copper powder exceeds 2 mm, the required amount of copper powder required for thermal spraying increases, and the spraying time also increases, which tends to increase the manufacturing cost. Both are not preferred because they become significant.

[0009]

In the conductor arm of the electric furnace according to any one of claims 1 to 3, aluminum is used for the material of the conductor arm.
For example, when manufacturing the same weight as the conventional copper or copper alloy conductor arm, because the specific gravity of aluminum is smaller than the specific gravity of copper, compared to the conventional copper or copper alloy conductor arm, The cross-sectional area S can be increased, and as a result, the electric resistance R can be extremely reduced as is apparent from the above equation (1). Also, the bending strength of aluminum is greater than that of copper,
For example, when a conductor arm is formed by welding an aluminum plate or the like into a frame shape having a substantially rectangular cross section, the mechanical strength of the conductor arm is increased as compared with a conventional copper or copper alloy conductor arm. Therefore, a reinforcing material can be unnecessary, and the weight of the conductor arm can be reduced by the weight of the reinforcing material, or the sectional area S of the conductor arm can be increased. Also, compared to welding copper plates or copper alloy plates, welding aluminum plates is extremely excellent in weldability, so that workability can be significantly improved. Further, since copper powder is sprayed on the joint surface with the water-cooled cable or the electrode holder, the joint surfaces to be connected (or contacted) can be made of copper, respectively, so that good contact properties can be obtained. When connecting the joint surface of the aluminum conductor arm and the joint surface of the copper water-cooled cable and the electrode holder as in the conventional case, contact between the joint surfaces due to poor contact due to contact between different materials. Resistance can be prevented from occurring. Further, since a thermal spraying method such as a plasma thermal spraying method is applied, the copper powder can be easily coated (or laminated) by spraying with a plasma jet or the like on each joint surface of the aluminum conductive arm. In particular, in the conductor arm of the electric furnace according to the second aspect, since the surface of the copper powder which is thickly sprayed on the joining surface is ground into a flat surface, it is possible to obtain better contact properties, and furthermore, it is possible to obtain each joint. The contact resistance between the surfaces can be reduced. In particular, in the conductor arm of the electric furnace according to the third aspect, since the conductor arm has a box-shaped cross section, sufficient strength can be obtained. In addition, since the inside of the conductor arm having a box-shaped cross section (or frame shape) is water-cooled, heat generation of the conductor arm can be prevented.

[0010]

In the conductor arm of the electric furnace according to claims 1 to 3, aluminum is used for the conductor arm.
By utilizing the difference in specific gravity from copper or copper alloy used in the conventional conductor arm and increasing its cross-sectional area S, the electric resistance R of the conductor arm can be extremely reduced, so Heat generation and power loss can be extremely reduced, and as a result, the power consumption can be reduced and the running cost can be reduced, so that the productivity and mass productivity of the steelmaking operation can be improved. Further, as compared with the conventional copper or copper alloy conductor arm, the mechanical strength of the aluminum conductor arm can be increased, so that a reinforcing material can be eliminated, and as a result,
Since the weight of the conductor arm can be reduced by the weight of the conventional reinforcing member, or the cross-sectional area S of the conductor arm can be increased, the running amount of power is further reduced as described above. The cost can be reduced, and the productivity and mass productivity of the steelmaking operation can be improved. Further, aluminum is superior to copper in terms of weldability, so that it is not necessary to limit the shape of the conductor arm of the electric furnace, and the shape can be appropriately changed according to various factors such as the shape of the electric furnace, The convenience can be greatly improved. Furthermore, since the copper powder is sprayed on the joint surface with the water-cooled cable or the electrode holder, it is possible to obtain good contact properties and to prevent the contact resistance between the respective contact surfaces, as described above. Furthermore, the running cost can be further reduced, and the productivity and mass productivity of the steelmaking operation can be significantly improved. In particular, in the conductor arm of the electric furnace according to the second aspect, since the surface of the copper powder is ground to obtain a better contact property and the contact resistance between the joining surfaces can be extremely reduced, further running can be achieved. The cost can be reduced and the productivity and mass productivity of the steelmaking operation can be significantly improved. In particular, in the conductor arm of the electric furnace according to the third aspect, since the conductor arm can obtain a sufficient strength, the iron plate used for securing the strength with the conventional copper or copper alloy conductor arm is used. And the like, so that the conductor arm can be reduced in weight, or the cross-sectional area S of the conductor arm can be increased by the weight of the reinforcement to further prevent power loss. Can be. Further, since heat is prevented by passing the cooling water through the conductor arm, power loss is further prevented, so that running costs can be reduced and productivity and mass productivity of the steelmaking operation can be significantly improved.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention. Here, FIG. 1 is a plan view of a conductor arm of the electric furnace according to one embodiment of the present invention, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG. 3 is a sectional view taken along line BB of FIG. FIG. 4
FIG. 5 is a side view taken along line CC of FIG. 1, FIG. 5 is a side view of a main part of a conductor arm of the electric furnace, FIG. 6 is a side view taken along line DD of FIG.
Is a sectional view of a main part of a conductor arm of the electric furnace, FIG. 8 is a plan view of a main part showing a state where an electrode holder is connected to the conductor arm of the electric furnace, and FIG. 9 is an electric diagram using the conductor arm of the electric furnace. FIG. 10 is a plan view of a main part of a conductor arm elevating device of an electric furnace using the conductor arm of the electric furnace.

As shown in FIGS. 1 to 10, a conductor arm 10 of an electric furnace according to an embodiment of the present invention includes a support arm 1.
0a, an electrode holder connection portion 10b attached to one longitudinal end (or distal end) of the support arm 10a and connecting the electrode holder 11, and the other longitudinal end (or rear end) of the support arm 10a. And a water-cooling cable connecting portion 10c to which a water-cooling cable (not shown) is attached. Hereinafter, these will be described in detail.

As shown in FIGS. 2 and 3, the supporting arm portion 10a is formed of a plurality of aluminum plates 10d having a thickness (t) of 20 mm ≦ t ≦ 30 mm and an outer shape (b) of 400 mm ≦ b ≦ 5.
The cooling water passage 10e is formed by welding into a substantially frame shape having a substantially rectangular cross section of 00 mm. Also, an aluminum plate 10d constituting the upper surface of the support arm 10a
As shown in FIGS. 1 and 3, the cooling water is supplied to the cooling water passage 10e or the cooling water is discharged from the cooling water passage 10e. Cooling water supply pipe (not shown) communicating with water passage 10e
A pipe connection portion (or flange) 10f for connecting a cooling water discharge pipe (not shown) and a cooling water discharge pipe (not shown) is provided everywhere. As shown in FIGS. 1, 5, 9, and 10, the conductor arm 10 is provided on the side of the electric furnace 13 on the aluminum plate 10d constituting the upper surface of the support arm 10a. When the conductor arm 10 is placed on the upper surface of the electrode support 14 via the insulator 15, a hook (not shown) for hanging the conductor arm 10 by a transfer device (not shown) such as an overhead crane is engaged. There are provided two hooking portions 10u. Also, an aluminum plate 10 constituting the lower surface of the support arm 10a
As shown in FIGS. 1, 2, 5, 9, and 10, the conductor arm 10 is attached to the upper surface of the electrode support 14 via fasteners such as bolts and nuts via an insulator 15 as shown in FIGS. (Not shown), a support mounting plate 10g formed wider than the aluminum plate 10d is mounted at two locations at a predetermined interval. In addition, the support arm 10
The support mounting plate 1 protruding below
A rib 10h is attached to 0g to prevent the support attachment plate 10g from bending or the like.

FIGS. 1, 7, 9, and 1 show the vicinity of the supporting arm 10a facing the electrode holder connecting portion 10b.
As shown in FIG. 0, the electrode 12 is bent downward at a predetermined angle and has a plane for arranging the center of the electrode 12 on a predetermined electrode arrangement circle shown by a dashed line in FIGS. It is formed to be bent at a predetermined angle toward the center of the electrode arrangement circle when viewed. The conductor arm 10
Is used for an electric furnace 13 such as an AC arc furnace such as a three-phase AC furnace, so that the conductor arm 20 of another electric furnace is used.
As shown in FIG. 10, in the vicinity of the support arm 10a facing the electrode holder connecting portion 10b, the conductor arm 20 is provided toward the center of the electrode arrangement circle, It is bent only at a predetermined angle. Further, in the conductor arm 30 of still another electric furnace, as shown in FIG. 10, the vicinity of the support arm portion 10a facing the electrode holder connection portion 10b is bent downward at a predetermined angle. At the same time, it is bent at a predetermined angle in a direction opposite to the conductor arm 10 of the electric furnace toward the center of the electrode arrangement circle in plan view. Also, as shown in FIGS. 1 and 5, the support arm 10a has a distal end support to which an electrode holder connection 10b is connected to one end in the longitudinal direction in order to improve the manufacturing workability of the support arm 10a. An arm 10y and a rear end supporting arm 10z to which a water-cooled cable connection 10c is connected at one end in the longitudinal direction. When the water-cooled cable connecting portion 10c is welded to one end in the longitudinal direction of the rear end side support arm portion 10z, when the support arm portion 10a undergoes a so-called thermal deformation due to heat at the time of welding, In order to reduce the work of removing the thermal distortion of the entire support arm 10a, the support arm 10a has a shorter axis than the distal end support arm 10y. In addition, a flange portion 1 is provided on each of opposing surfaces of the front end side support arm portion 10y and the rear end side support arm portion 10z.
0y 'and 10z' are provided.
0y 'and 10z' are abutted and fastened by fasteners (not shown) such as bolts and nuts, so that the support arm 1
0a is configured.

As shown in FIGS. 1, 4 and 7, the electrode holder connecting portion 10b is provided with a plurality of aluminum plates 10i.
Are welded into a substantially frame shape having a substantially rectangular cross section, and a plurality of aluminum plates 10j are accommodated therein for accommodating pressing means (not shown) such as an air cylinder or a hydraulic cylinder.
Of the cooling water passage 10 in the gap by accommodating the accommodating portion 10k formed by welding the
m. Also, as shown in FIGS. 7 and 8, the electrode holder 1 of the electrode holder connecting portion 10b
In order to close the cooling water passage 10m and to electrically connect with the joint surface of the terminal plate 11a of the electrode holder 11, a piston rod (shown in FIG. ) Is welded to an aluminum terminal plate 10x having an opening 10n formed therein. As shown in FIG. 7, the other surface of the electrode holder connection portion 10b has an opening 10v substantially at the center thereof for closing the cooling water passage 10m and storing the pressing means in the storage portion 10k. The formed aluminum plate 10p is welded. A surface (hereinafter, referred to as a bonding surface) of the aluminum terminal plate 10x facing the electrode holder 11 is sprayed by a spraying method such as a plasma spraying method, and the surface thereof is formed into a thickness (t) by a machining method such as a grinding method. _Cu ) A copper powder (hereinafter referred to as copper electrical contact) 10q ground to about 1 mm is provided. As shown in FIGS. 1 and 7, cooling water is supplied to the cooling water passage 10m, or the cooling water passage 1m is supplied from the cooling water passage 10m to the electrode holder connecting portion 10b.
In order to discharge the cooling water warmed at 0 m, a pipe connection portion (or flange) communicating with the cooling water passage 10 m and connecting a cooling water supply pipe (not shown) and a cooling water discharge pipe (not shown). 10w) are provided everywhere.

As shown in FIG. 8, the terminal plate 11a of the electrode holder 11 is brought into contact with the copper electrical contact 10q of the electrode holder connecting portion 10b. The terminal plate 11a is made of copper or a copper alloy and is formed in a substantially rectangular parallelepiped shape. An electrode holding plate 11b is provided on the surface of the terminal plate 11a facing the electrode 12 so that the surface facing the electrode 12 is formed in a substantially arc shape in a plan view. Also, the electrode holding plate 11b
In order to press the electrode 12 having one side contact with the electrode holding plate 11b in order to prevent the electrode 12 from dropping or the like, a plurality of copper plates or copper alloy plates are laminated, and the electrode pressing curved substantially in a U shape is formed. Both ends of the plate 11c are connected to the electrode holder connection portion 10b.
It is pressed and supported by being fixed to the side surface of the device by screwing or the like.

As shown in FIGS. 1, 5, and 6, the water-cooled cable connecting portion 10c is provided with a plurality of aluminum plates 10r.
Are welded into a substantially frame shape having a substantially concave cross section and
A rib 10s is formed between a pair of aluminum plates (hereinafter referred to as aluminum terminal plates) 10r in a direction substantially orthogonal to the longitudinal direction thereof.
Are formed by welding. The outer surfaces of the two aluminum terminal plates 10r of the water-cooled cable connecting portion 10c facing the water-cooled cable (hereinafter referred to as “joining surfaces”) are:
A copper powder (hereinafter referred to as copper electrical contact) 10t, which is thermally sprayed by a plasma spraying method or the like and whose surface is ground to a thickness (t _Cu ) of about 1 mm by a mechanical processing method such as a grinding method, is provided. .

The conductor arm 10 of the electric furnace is shown in FIG.
As shown in FIG. 2, an electrode provided vertically up and down on the side of the electric furnace 13 to enter and exit the electrode 12 through an electrode insertion opening (not shown) of a furnace lid 13a of the electric furnace 13. It is laid on the upper surface of the support 14 via an insulator 15. One end of the electrode support 14 is attached to an elevating means (not shown) such as a winch provided on the side of the electrode support 14, and a pulley (not shown) attached to a lower end of the electrode support 14. The wire (not shown), the other end of which is attached to one side surface of the electrode support 14 via a wire (not shown), is wound up and down by a lifting means (not shown), so that the wire can be vertically moved up and down. ing.

Next, a method for manufacturing the conductor arm 10 of the electric furnace according to one embodiment of the present invention will be described. First, a method for manufacturing the electrode holder connection portion 10b will be described. A copper powder is applied to the joint surface of the aluminum terminal plate 10x by a thermal spraying method such as a plasma spraying method to a thickness of 2 to 3 m.
After spraying with a thickness of m, the surface of the sprayed copper is subjected to a machining method such as a grinding method or a cutting method to obtain a thickness (t _Cu ).
Was processed into a copper electrical contact 10q of about 1 mm. Next, in order to increase the bonding strength of the copper electrical contact 10q, a diffusion process was performed. Next, after welding with a predetermined shape using another aluminum plate 10i, 10j, etc., heat treatment was performed to remove welding distortion. Thus, the electrode holder connection portion 10b of the conductor arm of the electric furnace according to the embodiment of the present invention was manufactured.

Next, a method of manufacturing the water-cooled cable connecting portion 10c will be described. After spraying copper powder on each joint surface of the two aluminum plates 10r by applying a spraying method such as a plasma spraying method in the same manner as described above, the surface of the sprayed copper is ground or cut. By a machining method such as a machining method, a copper electric contact 10t having a thickness (t _Cu ) of about 1 mm is provided,
Next, a diffusion process was performed to increase the bonding strength of the copper electrical contact 10t. Next, it was welded into a predetermined shape using another aluminum plate 10r and a rib 10s. Thus, the water-cooled cable connecting portion 10c of the conductor arm of the electric furnace according to the embodiment of the present invention was manufactured.

Next, a tip-side support arm 1 formed by welding a plurality of aluminum plates into a substantially frame shape having a substantially rectangular cross section.
The electrode holder connecting portion 10b was connected to the tip of 0y by welding. Further, after welding the water-cooled cable connection portion 10c to the rear end of the rear end side support arm portion 10z, heat treatment was performed to remove welding distortion. Finally, the flanges 10y ', 10z' of the front-side support arm 10y and the rear-side support arm 10z are abutted and connected by fasteners (not shown) such as bolts and nuts. The conductor arm 10 of the electric furnace according to the embodiment was manufactured.

As described above, according to the embodiment of the present invention, copper powder is sprayed on each joint surface of the conductor arm 10 of the aluminum electric furnace with the water-cooled cable and the electrode holder 11, and then the surface thereof is sprayed. Has been ground or cut into a smooth shape, so that good contact with the joint surface with the water-cooled cable or the electrode holder 11 can be obtained, and the contact resistance between the contact surfaces can be reduced. Heat generation and power loss can be extremely reduced. As a result, running cost can be reduced by reducing power consumption, and productivity and mass productivity of steelmaking operation can be significantly improved.

The embodiment of the present invention has been described above.
The present invention is not limited to these embodiments, and all changes in conditions without departing from the gist are within the scope of the present invention.

[Brief description of the drawings]

FIG. 1 is a plan view of a conductor arm of an electric furnace according to one embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a side view taken along a line CC in FIG. 1;

FIG. 5 is a side view of a main part of a conductor arm of the electric furnace.

FIG. 6 is a side view taken along a line DD in FIG. 5;

FIG. 7 is a side sectional view of a main part of a conductor arm of the electric furnace.

FIG. 8 is a main part plan view showing a state where an electrode holder is connected to a conductor arm of the electric furnace.

FIG. 9 is a side view of a main part of a conductor arm lifting / lowering device of the electric furnace using the conductor arm of the electric furnace.

FIG. 10 is a plan view of a main part of a conductor arm lifting / lowering device of the electric furnace using the conductor arm of the electric furnace.

[Explanation of symbols]

Reference Signs List 10 Conductor arm of electric furnace 10a Support arm 10b Electrode holder connection 10c Water cooling cable connection 10d Aluminum plate 10e Cooling water passage 10f Pipe connection (flange) 10g Post mounting plate 10h Rib 10i Aluminum plate 10j Aluminum plate 10k Storage section 10m Cooling water passage 10n Opening 10p Aluminum plate 10q Copper powder (copper electrical contact) 10r Aluminum plate 10s Rib 10t Copper powder (copper electrical contact) 10u Hook 10v Opening 10w Piping connection (flange) 10x Aluminum terminal plate 10y Tip support arm 10z Rear support arm 10y 'Flange 10z' Flange 11 Electrode holder 11a Terminal plate 11b Electrode holding plate 11c Electrode pressing plate 12 Electrode 13 Electric furnace 13a Furnace lid 14 Electric Conducting arm conductor arm 30 an electric furnace of the strut 15 insulator 20 electric furnace

Claims (3)

(57) [Claims] 1. A conductor arm of an electric furnace to which a water-cooled cable is connected at one end and an electrode holder is connected at the other end, and wherein the conductor arm of an electric furnace supplies power from the water-cooled cable to an electrode mounted on the electrode holder. A conductor arm for an electric furnace, wherein the conductor arm is made of aluminum, and copper powder is sprayed on a joint surface of the conductor arm with the electrode holder and a joint surface of the water-cooled cable. 2. The conductor arm of an electric furnace according to claim 1, wherein each of the joining surfaces is ground to a flat surface after the copper powder is sprayed thickly. 3. The conductor arm has a box-shaped cross section.
3. The conductor arm of an electric furnace according to claim 1, which has sufficient strength and is internally water-cooled.