KR20160068095A - Apparatus for preventing arc of electro furnace roof - Google Patents

Abstract

Disclosed is an apparatus for preventing arc of electric furnace roof According to an embodiment of the present invention, the apparatus includes: an arc transmitting part opening and closing an upper portion of a heating furnace having an opened top, installed on one side of the roof having an electrode hole into which an electrode rod is inserted, and inducing arc current generated from the upper portion of the roof to flow so as to transmit the current; and an arc earthing part installed on one side of the heating furnace so as to earth arc current flowing in the arc transmitting part and attached or detached from the arc transmitting part by interlockedly driven with an opening and closing motion of the roof.

Description

FIELD OF THE INVENTION [0001] The present invention relates to an electric arc furnace,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a loop arc prevention device for an electric furnace, and more particularly, to a loop arc prevention device for an electric furnace that prevents equipment damage due to an arc current generated in an upper portion of a loop.

Generally, an electric furnace is a furnace for manufacturing steel by utilizing a thermal effect of electric current, and an electric furnace is mainly used for manufacturing of electro-thermal chemical products, refining of metal, melting and heat treatment.

1, the electric furnace includes a heating furnace 10 in which scrap is charged and melted, a loop 11 covering the upper portion of the heating furnace 10, A plurality of electrode arms 12 that are vertically movable up and down to the inside of the electrode arms 10, a plurality of electrode arms 13 that support the electrodes 12, A hydraulic cylinder 14 for moving the electrode arm 13 up and down when the electrode 12 needs to be lifted or lowered, a power supply 15 such as a transformer for supplying power to each electrode arm 13, a power supply 15 And a power cable 16 for connecting the electrode arm 13 and the electrode arm 13 to each other.

The work of the electric furnace is carried out by charging the scrap which is the main material in the heating furnace 10 and moving the loop 11 to the upper part of the heating furnace 10 to cover the plurality of electrodes 12, Is inserted into the heating furnace (10) through the heater (17), and electricity is applied to move up and down in the heating furnace (10) to melt the scrap inside the heating furnace (10) by electric discharge.

2, an arc current generated when the electrode 12 is brought into contact with the electrode hole 17 now around the electrode hole 17 is supplied to the loop 11 through the loop 11. In this case, 11) Generating an electric arc with the upper contact surface of the heating furnace 10 in contact with the cooling water main pipe leads to damage of the cooling water main pipe of the loop 11, thereby causing leakage of cooling water frequently.

Korean Registered Patent No. 1330318 (published Nov. 20, 2013) Korea Public Utility Model Office 2001-0001284 (Released on January 15, 2001) Korean Registered Patent No. 1022438 (published on Mar. 15, 2011)

Embodiments of the present invention provide an apparatus for preventing a loop arc in an electric furnace that can prevent equipment damage due to an arc current generated in an upper portion of a loop during an electric furnace operation.

The problems to be solved by the present invention are not limited to the above-mentioned problems, and other matters not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided an arc furnace including an arc transfer unit installed at one side of a loop having an electrode hole into which an electrode rod is inserted to open and close an upper part of a heating furnace, And an arc grounding portion provided at one side of the heating furnace to ground the arc current flowing in the arc transferring portion and configured to be in contact with or disengaged from the arc transmitting portion in cooperation with the opening and closing operation of the loop, An arc prevention device can be provided.

The arc transmission portion includes an induction line disposed on the upper side of the loop so as to flow the arc current to a connection terminal that contacts the ground terminal of the arc ground portion.

The arc transmission unit further includes an operation arm for pressing and rotating the arc ground unit so that a ground terminal of the arc ground unit can contact the connection terminal when the loop covers the upper portion of the heating furnace.

Wherein the arc grounding portion includes a rotary arm rotatably mounted on a rotary shaft, the rotary arm having a first position at which the ground terminal contacts the connection terminal and a second position at which the ground terminal is separated from the connection terminal, Position.

Further, the rotary arm may be moved to the first position when the operation arm is pressed.

The arc grounding portion may further include an elastic restoring portion for elastically supporting the rotary arm to move the rotary arm to the second position when an external force is removed.

The arc grounding portion further includes an elastic pressing portion for pressing the ground terminal to the connection terminal to maintain contact between the ground terminal and the connection terminal at the first position.

And a working rib extending from one side of the rotary arm so as to be in contact with the working arm when the loop closes the heating furnace.

Further, the contact surface formed on the upper side of the operating rib may be inclined downward to contact the operating arm.

The elastic restoring portion may include a restoring rod that is installed to be linearly reciprocable and contacts with one side of the rotating arm, and a restoring spring that elastically supports the restoring rod to provide the elastic force to move the rotating arm to the second position do.

The elastic pressing portion includes a pressing rod which is provided so as to be linearly reciprocally movable from one side of the rotary arm and has the grounding terminal at an end thereof and a pressing rod which elastically supports the pressing rod in a direction in which the grounding terminal presses the connecting rod Spring.

Further, the elastic pressing portion may further include a ground terminal holder to which the ground terminal is detachably installed, and the ground terminal holder may be rotatably coupled to the end portion of the pressing rod.

Embodiments of the present invention can prevent facility accidents due to an arc current generated in an upper portion of a loop during an electric furnace operation and can secure the safety of an operator.

Fig. 1 schematically shows a conventional electric furnace working process.
FIG. 2 shows an arc generated state when a conventional electric furnace is operated.
3 is a perspective view showing a loop arc prevention device in a state in which a heating furnace is opened according to an embodiment of the present invention.
Fig. 4 is an enlarged view of the loop arc prevention device portion of Fig.
5 is a perspective view showing a loop arc preventing device in a state in which a heating furnace is closed according to an embodiment of the present invention.
Fig. 6 is an enlarged view of a portion of the loop arc prevention device of Fig. 5;

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments described below are provided by way of example so that those skilled in the art will be able to fully understand the spirit of the present invention. The present invention is not limited to the embodiments described below, but may be embodied in other forms. In order to clearly explain the present invention, parts not related to the description are omitted from the drawings, and the width, length, thickness, etc. of the components may be exaggerated for convenience. Like reference numerals designate like elements throughout the specification.

Also, terms including ordinals such as " first, " " second, " and the like can be used to describe various elements, but the elements are not limited by terms. Terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

The terms used in the present application are used to illustrate the embodiments and are not intended to limit or limit the invention, and the singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprise", "comprising", and the like are intended to specify the presence of stated features, integers, steps, components, or combinations thereof, and may include one or more other features, Steps, elements, or combinations thereof, as a matter of convenience, without departing from the spirit and scope of the invention. Also, when a part is referred to as being "connected" to another part, it includes not only a direct connection but also an indirect connection between the other parts.

FIG. 3 is a perspective view showing a loop arc prevention device in a state in which a heating furnace is opened according to an embodiment of the present invention, and FIG. 4 is an enlarged view of the loop arc prevention device portion of FIG.

3 and 4, an apparatus for preventing a loop arc in an electric furnace according to an exemplary embodiment of the present invention includes an arc conveyor installed at one side of a loop 30 for opening and closing an upper part of a heating furnace 20, And an arc grounding part 50 installed at one side of the heating furnace 20 so as to be able to contact the arc transmitting part 40.

An electrode hole 21 is formed in the central region of the loop 30 so that the electrode can be introduced into the heating furnace 20. The electrode is inserted into the heating furnace 20 through the electrode hole 21, As shown in FIG.

The electrode hole 21 in the present embodiment is an example in which three holes are formed in the central region of the loop 30 so that three electrodes for supplying three-phase (R, S, T) currents can be inserted And the number of the electrode holes 21 can be changed as needed.

Further, although not shown, the loop 30 may be provided with a cooling water pipe arranged along a predetermined path so that cooling water for cooling the loop 30 flows.

The arc transmission portion 40 is provided between the electrode 30 and the electrode hole 21. The arc transmission portion 40 is formed in the vicinity of the electrode hole 21, So that the arc current can flow to the arc grounding part 50.

The arc transmission unit 40 includes an induction line 41 disposed on the upper side of the loop 30 and an induction line 41 disposed on the upper side of the loop 30 so as to attract and flow an arc current generated in an irregular place and shape, And a connection terminal 42 provided on one side of the loop 30 so as to be electrically connected.

The guide wire 41 may be formed of a wire made of a conductive metal disposed along a predetermined path on the upper side of the loop 30 and may be made of a wire- As shown in FIG. The induction line 41 may be made of a metal material such as copper, iron, or the like through which a current flows smoothly. The induction line 41 may have such a thickness that an arc current generated from the upper portion of the loop 30 can sufficiently flow. The induction line 41 is divided into a first portion arranged in the ring shape around the electrode hole 21 where arc generation is relatively frequent and a second portion arranged in the ring shape in the vicinity of the upper edge of the loop 30 And the first portion and the second portion may be electrically connected to each other through a lead.

The connection terminal 42 may be connected to one side of the guide wire 41 so as to be electrically connected to the guide wire 41. [ The connection terminal 42 is a portion which is in contact with the ground terminal 55 electrically connected to the ground wire 58 for flowing an arc current flowing through the induction line 41 to the ground and is made of a carbon material As shown in FIG.

The connection terminal 42 may be detachably attached to the connection terminal holder 44 provided at one side of the edge of the loop 30 by bolt fastening or attaching / .

The arc transmission portion 40 also includes an operation arm 47 for pressing and rotating the arc ground portion 50 when the loop 30 covers the open upper portion of the heating furnace 20. [

The operation arm 47 may be provided in the form of a rib extending downward from the connection terminal holder 44 and the lower end of the operation arm 47 may be connected to the arc ground portion 50 And can contact the ribs 52.

The arc grounding part 50 is provided on one side of the side of the heating furnace 20 and electrically connected to the connection terminal 42 of the arc transmission part 40 when the roof 30 closes the opened upper part of the heating furnace 20 And conducts a function of grounding so that an arc current flowing in the induction line 41 flows to the ground as it is connected.

The arc grounding part 50 is connected to the grounding terminal 55 of the arc grounding part 50 and the grounding terminal 55 of the arc transmitting part 40 in cooperation with the opening and closing operation of opening and closing the open upper part of the heating furnace 20. And may be provided so as to come into contact with or come off contact with the connection terminal 42.

To this end, the arc grounding part 50 includes a working rib 52 which is in press contact with the operating arm 47 of the arc transmitting part 40 when the loop 30 descends, And a grounding terminal 55 which is in contact with the grounding terminal 42.

The rotary arm 51 may be rotatably coupled to an axial bracket 25 provided on a mounting plate 23 provided to extend outward from one side of the heating furnace 20, The ground terminal 55 provided on the rotary arm 51 is rotated in the clockwise or counterclockwise direction with respect to the rotary shaft 54 and the first position where the ground terminal 55 is in contact with the connection terminal 42, To the second position.

The operating rib 52 is extended from one side of the rotary arm 51 toward the sidewall of the heating furnace 20 so as to be able to contact with the operating arm 47 of the arc transmission portion 40 while the loop 30 descends, And the contact surface 53 formed on the upper side in contact with the operation arm 47 may be inclined downward to induce smooth entry of the operation arm 47 when the operation arm 47 is pressed.

The arc grounding part 50 further includes an elastic restoring part 70 for moving the rotary arm 51 to a second position where the grounding terminal 55 is separated from the connection terminal 42 while the external force is not applied do.

The elastic restoring portion 70 includes a restoring rod 71 that is linearly reciprocally movable in the vertical direction in the rod housing 73 provided on the mounting plate 23 and a restoring spring 72 for resiliently supporting the restoring rod 71 ).

The restoring spring 72 resiliently supports the restoring rod 71 so that the pressing portion 74 provided at the upper end of the restoring rod 71 comes into pressure contact with the bottom surface of the actuating rib 52. Therefore, (51) to the second position.

The arc grounding portion 50 includes an elastic pressing portion 60 for maintaining a predetermined contact force between the ground terminal 55 and the connection terminal 42 at a first position where the ground terminal 55 contacts the connection terminal 42, .

The elastic pressing portion 60 includes a pressing rod 61 provided to be capable of linearly reciprocating back and forth in the horizontal direction from one side of the upper portion of the rotary arm 51 and having a ground terminal 55, (Not shown).

The ground terminal 55 may be mounted on the ground terminal holder 56 so as to be electrically connected to the ground line 58 connected to the ground and may be provided in the form of a plate made of carbon material. Also, the ground terminal 55 may be detachably attached to the ground terminal holder 56 by a bolt fastening method or a detachable method so that the ground terminal 55 can be easily replaced when abrasion occurs after use for a predetermined period of time.

The ground terminal holder 56 is provided on the side of the connection terminal 42 for the purpose of smooth contact between the ground terminal 55 and the connection terminal 42 while the rotary arm 51 rotates to the first position. And may be rotatably coupled with the holder shaft 57 at an end thereof.

The pressing spring 62 urges the pressing rod 61 in a direction in which the connecting terminal 42 and the grounding terminal 55 come into tight contact with each other as the pressing rod 61 elastically supports the pressing rod 61 in the direction in which the pressing rod 61 presses the connecting terminal 42 to provide.

Hereinafter, the operation of the loop arc prevention apparatus of the electric furnace according to the embodiment of the present invention will be described.

First, scrap charging is performed in a state that the roof 30 is opened for scrap charging in the electric furnace 20, and when the scrap charging is completed, the opening of the electric furnace 20 is completed as shown in Figs. 3 and 4 The loop 30 is lowered toward the opened upper portion of the electric furnace 20 so as to close the upper portion of the electric furnace 20. [

The operating arm 47 provided on one side of the loop 30 comes into contact with the operating rib 52 to press the operating rib 52 so that the rotating arm 54 can move the loop 30 .

5 and 6, the connection terminal 42 of the arc transmission portion 40 and the arc ground portion 50 are connected to each other, The grounding terminal 55 of the power supply unit is energized as it is in contact with each other.

The arc current generated in the upper portion of the loop 30 is attracted to the induction line 41 provided on the upper side of the loop 30 and flows to the ground line 58 through the ground terminal 55 in contact with the connection terminal 42 And it flows to the earth.

Therefore, it is possible to prevent damage to the cooling water pipe installed in the roof 30 due to an arc current generated irregularly in the upper portion of the roof 30 during the electric furnace operation, It is possible to reduce safety accidents of workers.

The foregoing has shown and described specific embodiments. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention as defined in the appended claims.

20: heating furnace, 30: loop,
40: arc transmission part, 41: lead wire,
42: connection terminal, 47: operation arm,
50: arc ground portion, 51: rotary arm,
52: operating rib, 53: contact surface,
54: rotation shaft, 55: ground terminal,
56: ground terminal holder, 60: elastic pressing portion,
61: pressing rod, 62: pressing spring,
70: elastic restoring portion, 71: restoring rod,
72: restoration spring.

Claims (12)

An arc transfer unit installed at one side of a loop having an electrode hole into which an electrode rod is inserted to open and close an upper part of a heating furnace, and to induce and deliver an arc current generated in the upper part of the loop; And
And an arc grounding part installed at one side of the heating furnace to ground the arc current flowing in the arc transmitting part and being in contact with or disengaged from the arc transmitting part in conjunction with the opening and closing operation of the loop, Loop arc prevention device. The method according to claim 1,
Wherein the arc transmission portion includes an induction line disposed on the upper side of the loop so that the arc current flows in a connection terminal that contacts the ground terminal of the arc ground portion. 3. The method of claim 2,
Wherein the arc transmission portion further comprises an operation arm for pressing and rotating the arc ground portion so that the ground terminal of the arc ground portion can contact the connection terminal when the loop covers the upper portion of the heating furnace. Device. The method of claim 3,
Wherein the arc grounding portion includes a rotary arm rotatably mounted on a rotary shaft,
Wherein the rotary arm is rotatable to a first position where the ground terminal makes contact with the connection terminal and a second position where the ground terminal is separated from the connection terminal. 5. The method of claim 4,
Wherein the rotary arm moves to the first position when the operation arm is pressed and contacted. 6. The method of claim 5,
Wherein the arc grounding portion further comprises an elastic restoring portion for elastically supporting the rotary arm to move the rotary arm to the second position when an external force is removed. The method according to claim 6,
Wherein the arc grounding portion further comprises an elastic pressing portion for pressing the ground terminal to the connection terminal so as to maintain contact between the ground terminal and the connection terminal at the first position. 5. The method of claim 4,
And a working rib extending from one side of the rotary arm so as to be in contact with the operation arm when the loop closes the heating furnace. 9. The method of claim 8,
And the contact surface formed on the upper side of the operating rib to be in contact with the operating arm is inclined downward. The method according to claim 6,
Wherein the elastic restoring portion includes a restoring rod which is installed to reciprocate linearly and makes contact with one side of the rotating arm and a restoring spring that elastically supports the restoring rod to provide the elastic force for moving the rotating arm to the second position Loop arc prevention device in electric furnace. 8. The method of claim 7,
Wherein the elastic pressing portion includes a pressing rod which is provided so as to be linearly reciprocally movable from one side of the rotary arm and has the ground terminal at an end thereof and a pressing spring which elastically supports the pressing rod in a direction in which the ground terminal presses the connecting terminal, Wherein the loop arc prevention device of the electric furnace includes: 12. The method of claim 11,
Wherein the elastic pressing portion further includes a ground terminal holder to which the ground terminal is detachably mounted,
And the ground terminal holder is rotatably coupled to an end of the pressing rod.

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