JPH0942851A - Equipment for preventing accident of breakage of electrode in electric furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent occurrence of an accident that a graphite electrode is broken due to a tilt of a furnace cover in the course of an operation, in regard to an electric furnace wherein metal is melted by the heat of an arc generated by the graphite electrode suspended into the furnace. SOLUTION: In regard to an arc heating type electric furnace having a construction wherein a furnace cover 4 is hung down on a furnace body 3 elevatably and also a graphite electrode 6 is suspended into the furnace body through the furnace cover, an angle sensor 18 is provided on the furnace cover 4 and a tilt of the furnace cover being larger than an allowable angle, which takes place when the furnace cover is lowered and put on the furnace body, is detected by a control device 19. On detection of the tilt, the lowering of the furnace cover is stopped, while an alarm is issued.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for preventing breakage of a graphite electrode during operation in an electric furnace for heating and melting a metal by hanging a graphite electrode in the furnace to generate an arc. is there.

[0002]

2. Description of the Related Art FIG. 2 shows an outline of the entire apparatus of a conventional arc-heating type ladle refining furnace. In the figure, 1 is a trolley provided on a rail 2 so that it can travel, and 3 is a trolley on the trolley 1. A furnace body that is tiltably supported, 4 is a dome-shaped furnace lid that covers the furnace body 3, 5 is an electrode holder, and 6 is a furnace body that is held by the electrode holder 5 and penetrates the furnace lid 4. Graphite electrode hanging in 3; 7
Is a dust collecting hood formed in the electrode 6 penetrating portion on the furnace lid 4,
Reference numeral 8 is a suction duct provided in the hood 7. Hearth lid 4
Is suspended by a plurality of wires 9 so as to maintain a horizontal state, and the wires 9 are attached to the pulley 1 provided on the upper floor floor 10.
It is connected to the furnace lid lifting drive device 12 via 1. The furnace lid lifting drive device 12 is driven to drive the wire 9
And the furnace lid 4 is moved up and down to cover the furnace body 3. Reference numeral 13 is an electrode lifting device provided at the base of the electrode gripper 5.

By the way, during operation, slag or the like adheres and deposits on the upper surface of the furnace body 3, but when the furnace lid 4 is lowered, the furnace lid 4 is inclined because it rides on the slag, and may be greatly inclined.
However, the through hole of the electrode 6 and the electrode 6 formed in the hood 7 is set to a small clearance in order to secure the dust collecting effect, and when the inclination of the furnace lid 4 becomes large, the electrode 6 comes into contact with the inner surface of the through hole. It will be. Therefore, the electrode 6 may be broken. And once such an electrode breakage accident occurs, not only time loss for recovery but also economically large loss, which is also dangerous.

[0004]

Therefore, the present invention is intended to prevent the electrode breakage accident in the electric furnace as described above.

[0005]

To this end, the present invention is of an arc heating type in which a furnace lid is hung up and down on a furnace body, and a graphite electrode is pierced through the furnace lid and hung in the furnace body. In the electric furnace, an angle sensor is provided on the furnace lid, and the controller detects an inclination of the furnace lid that is equal to or more than the allowable angle when the furnace lid is lowered to cover the furnace body, and the lowering of the furnace lid is stopped. At the same time, it is characterized by issuing an alarm. By stopping the lowering of the furnace lid when the furnace lid is tilted, it is possible to reliably prevent breakage without applying unnecessary bending force to the graphite electrode, and take necessary measures by warning such a situation. You can

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a specific example of the present invention will be described with reference to FIG. The same reference numerals as those in FIG. 2 in FIG. 1 indicate the same components, 3 is a furnace body, 4 is a furnace lid, 5 is an electrode holder, 6 is a graphite electrode, 7 is a dust collecting hood, 8 is a suction duct, Reference numeral 9 is a wire, 11 is a pulley, 12 is a furnace lid lifting / lowering drive device, and 13 is an electrode lifting / lowering device. Molten steel a is held in the molten state in the furnace body 3 by arc heating due to discharge with the graphite electrode 6.
b is molten slag. The furnace lid lifting device 12 in this case consists of a cylinder which indexes the wire 9. Further, the electrode elevating / lowering device 13 is configured so that the winch 15 is rotated by the motor 14 and the wire 16 is indexed so that the column 17 can be moved up and down.

Reference numeral 18 is an angle sensor provided on the furnace lid 4 for converting the inclination angle of the furnace lid 4 into an electric signal, 19 is a control device, and the control device 19 is an electric sensor obtained from the angle sensor 18. The tilt angle of the furnace lid 4 is read from the signal, the allowable tilt angle preset in the control device 19 is compared with the read tilt angle, and when the tilt angle of the furnace lid 4 is equal to or more than the allowable tilt angle, A command is issued to the furnace lid lift drive device 12 to prohibit the descent of the furnace cover 4, and at the same time a command is issued to the alarm device 20 so that an alarm such as a buzzer or a warning lamp can be displayed.

Therefore, when the furnace lid elevating / lowering device 12 is operated to lower the furnace lid 4 and cover the furnace lid 4 on the furnace body 3, slag and the like are accumulated on the upper surface of the furnace body 3 In the case where the furnace lid 4 is about to tilt, the tilt angle is detected by the control device 19 through the angle sensor 18 and the lowering of the furnace lid 4 is suddenly stopped. It is possible to prevent the electrode 6 from breaking. It is also possible to add a mechanism for automatically raising the furnace lid 4 again after stopping the lowering of the furnace lid 4 in this way.

[0009]

As described above, the electrode breakage accident prevention device for an electric furnace according to the present invention eliminates the risk of electrode breakage by detecting the inclination angle of the furnace lid when it is lowered, and at the same time enables appropriate warning action. Therefore, there is a beneficial effect that an accident can be eliminated and safe operation can be performed, and a large amount of time and economic loss associated with the occurrence of the accident can be avoided.

[Brief description of drawings]

FIG. 1 is a signal system diagram schematically showing an electrode breakage accident prevention device in an electric furnace according to the present invention.

FIG. 2 is a schematic diagram of the entire apparatus of a ladle refining furnace.

[Explanation of symbols]

 3 Furnace Body 4 Furnace Lid 5 Electrode Grip 6 Graphite Electrode 7 Dust Collection Hood 9 Wire 11 Pulley 12 Furnace Lid Lifting Drive Device 13 Electrode Lifting Device 18 Angle Sensor 19 Control Device 20 Alarm Device

Claims (1)

[Claims] 1. An arc heating type electric furnace in which a furnace lid is hung up and down on a furnace body and a graphite electrode penetrates the furnace lid and hangs down into the furnace body. An angle sensor is provided on the furnace lid. Is provided, and when the furnace lid is lowered to cover the furnace body, the inclination of the furnace lid which is equal to or greater than the allowable angle is detected by the control device, and the lowering of the furnace lid is stopped and an alarm is issued at the same time. A device for preventing electrode breakage accidents in electric furnaces.