JPS60208084A - Method and device for regulating length of electrode of arc furnace - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for adjusting the length of an electrode in an arc furnace.

Conventionally, there was no suitable device for adjusting the electrode length of an arc furnace, so the length of the electrode under the electrode holder, the tab, and the length below the neck of the electrode were adjusted using the furnace body as shown in Figure 1. Melting of the scrap b charged in a is started, and after a while the electricity is stopped, the electrode holder e is unclamped, and the electrode d is
After scraping the holder bK and raising the holder e to an appropriate position, the electrode d was clamped again to complete the adjustment of its length.

According to such a conventional method, power transmission is stopped in the middle of operation, which causes a large loss of time, and when electrode d (i-) is unclamped, electrode d falls and a shock is applied to electrode d. Since the operator relies on his or her intuition to raise the holder e, that is, the length under the neck of the electrode d depends on the intuition of the operator, there is variation in the length under the neck after adjustment.
Since the impedance of each electrode d becomes unbalanced and the input power becomes unbalanced, melting becomes unstable and if the length is still insufficient, readjustment becomes necessary, and conversely, if it is too long, the furnace lid C During movement of the electrode 1ia, the lower tip of the electrode d may interfere with the furnace body a, causing the electrode 1ia to break.

The present invention makes it possible to adjust the electrodes during furnace repair after tapping or during preparation for scrap charging without temporarily interrupting the operation of the arc furnace, thereby reducing loss of operating time. Moreover, without relying on the operator's intuition, it is possible to maintain impedance balance during operation by accurately applying a constant pressure to the length of the electrode neck, and to perform stable melting, as well as applying a shock to the electrode when changing the electrode. It is an object of the present invention to provide a method and apparatus for adjusting the length of an electrode in an arc furnace, which can perform detailed unit consumption management of the electrode without causing any problems.

Therefore, in the method of the present invention, the lid of the arc furnace is opened and the lower tip of the electrode is brought into contact with the upper surface of the electrode pedestal installed at a constant level outside the furnace body, and then the trap, The method is characterized in that the electrode holder is unclamped, raised to a predetermined position, and then the holder is clamped again to keep the length of the electrode under the neck constant.

Further, the device of the present invention has an electrode holder provided at a position corresponding to directly below the electrode when the furnace lid is opened in an arc furnace so as to maintain a constant level outside the furnace body, and , a position detector that detects the vertical position of the electrode holder, and a detection signal from this position detector is input to calculate the length under the neck and amount of wear of the electrode, and output a control signal according to the amount of wear. It is characterized by being equipped with an arithmetic controller that performs the following operations.

An embodiment of the present invention will be described below with reference to FIG.

In FIG. 2, reference numeral 1 denotes a furnace lid, which has been rotated to the outside of the furnace body (not shown) and opened in order to repair the furnace after tapping steel or to prepare for scrap charging. 2 is the electrode used in the previous operation, 6 is the electrode holder, 4 is the support arm, 5 is the electrode lifting mast, 6 is the electric motor for electrode lifting, 7
Up to this point, there is no major difference from the conventional one, including the speed reduction groove, the 8-wire hoist, the 9-wire connecting electrode, and 10 the electrode connecting device.

Eleven electrode pedestals are installed at positions just below the electrodes 2 when the furnace lid 1 is open so as to maintain a constant level H1 outside the furnace body. Reference numeral 12 denotes a pedestal lifting device that adjusts the level H4 of the electrode pedestal 11 or lowers the pedestal 11 to level H2 to avoid interference with the furnace body when the furnace body is tilted.

Reference numeral 13 denotes a first position detector for detecting the vertical position of the electrode holder 3. In this embodiment, a pulse generator is attached to the speed reducer 7, but a Sergino transmitter or the like may also be used. Reference numeral 14 denotes a second position detector for detecting the vertical position of the electrode joint device 10, and although it is a pulse generator in this embodiment, a sershin oscillator or the like may also be used. 15 is an arithmetic controller which will be described later, and 16 is an electrode lifting/lowering control circuit.

In the electrode adjustment device for an arc furnace configured as shown in FIG. 2, the furnace lid 1 is rotated and the lower tip of the electrode 2 is placed at a constant level H1. It is lowered until it touches the top surface of the stand 11. Then, the position H3 of the electrode holder 3 in this contact state is detected by the first position detector 13. Next, the arithmetic controller 15 inputs the H6 detection signal detected by the detector 13 to determine the length L+ (Hs H+) of the electrode 2, and calculates the length L+ (Hs H+) of the electrode 2 after this operation. Since the difference in the length under the neck before operation is the wear amount ΔL1 of the electrode 2, this wear amount ΔL is completely calculated. Next, unclamp the electrode holder 3 and place it at a predetermined position H.
4 (to the position 5), the holder 3 clamps the electrode 2 again. Then, the length of electrode 2 below the neck is measured. becomes. That is, the electrode 2 has been changed by ΔL, so by repeating this every time before operation, it is possible to operate with the length of the electrode 2 under the neck constant.

It is preferable that a limit switch (not shown) is provided when the electrode 2 is lowered so that it comes into contact with the electrode pedestal 11, and that pressure is applied to stop the electrode lifting motor 6 by operating the limit switch. In addition, a spring (not shown) may be added to the electrode holder 11 to provide a shoe/feature in the vertical direction to make the above-mentioned contact smooth. When the electrode 2 is placed on the electrode pedestal 11, the pedestal 11 is moved due to the weight of the electrode 2.
is slightly lowered, causing an error in the constant level H5. In such a case, the electrode 2 may be held at a position where the error has been corrected.

In this way, if the holding of the electrode 2 is repeated, the electrode 2
The remaining length L2 decreases, and eventually it becomes impossible to change the grip. Therefore, when the remaining length L2 falls below a certain level, the operator is given a command to connect the electrodes in advance, and the electrodes are prepared during operation, so that the electrodes can be connected during the next length measurement. That is, when the electrode was added by the electrode adding device 10 last time, the second position detector 14 provided in the electrode adding device 10 detected the vertical stroke of the electrode adding device 10, and the added electrode 9, and the difference between this and H3 detected by the first position detector 16 (H
5-H,) allows the length of the electrode on the electrode holder 5 to be adjusted. From this, the remaining length L2 can be calculated by subtracting the amount of wear that is subtracted each time, and it can therefore be determined whether or not an electrode joint is necessary. In addition, as a practical matter, if two or more electrodes are connected at the same time, there may be a loss of time, and it is not good to connect them too quickly, so leave an appropriate margin for the remaining length L2 of the electrode. Then, add the smallest remaining length L2 in the first run, leave the others as they are, operate, add the second smallest length in the second run, and add the sixth smallest in the sixth run. Try to add things. Furthermore, since errors in the remaining electrode length L2 due to deflection are accumulated each time the electrode 2 is changed, it is better to correct the errors when replacing the electrode.

As described above, the method of the present invention involves opening the furnace lid of the arc furnace, bringing the lower tip of the electrode into contact with the upper surface of the electrode pedestal installed at a constant level outside the furnace body, and then K. Since this method involves unclamping the electrode holder, raising it to a predetermined position, and then clamping the holder again to keep the length of the electrode under the neck constant, there is no need to temporarily interrupt the operation of the arc furnace. Electrodes can be adjusted during furnace repair after steel tapping or during preparation for scrap charging, reducing loss of operating time. It is possible to maintain impedance balance during operation by accurately applying a constant pressure to the length under the neck, and to perform stable melting.In addition, there is no impact on the electrode when changing the electrode, and the fine-grained consumption rate of the electrode can be achieved. The effects of this, such as being able to carry out management, are extremely large.

Further, the device of the present invention includes an electrode pedestal provided at a position corresponding to directly below the electrode when the furnace lid is opened in an arc furnace so as to maintain a constant level outside the furnace body, and This is a position detector that detects the vertical position of the electrode boulder.
Since the present invention is equipped with an arithmetic controller that inputs the detection signal from the position detector, calculates the length under the neck and the amount of wear of the electrode, and outputs a control signal according to the amount of wear. All methods can be carried out reliably with equipment,
Moreover, the device is not particularly complicated and has a simple configuration, so the effects it brings are extremely large.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional front view of a conventional arc furnace, and FIG. 2 is an explanatory diagram showing an embodiment of the apparatus of the present invention. 1... Furnace lid, 2... Electrode, 3... Electrode holder, 1
0... Electrode connecting leg device, 11... Electrode pedestal, 12...
・Pedestal lifting device, 13° 14...Position detector, 15・
... Arithmetic controller, 16... Electrode elevation control circuit.

Claims (1)

[Claims] 1. Open the furnace lid of the arc furnace so that the lower tip of the electrode is in contact with the upper surface of the electrode pedestal installed at a constant level outside the furnace body, and then The holder is unclamped and raised to a predetermined position, and then the holder is clamped again to keep the length of the electrode under the neck constant.
How to adjust the electrode length of an arc furnace. 2. Equipped with an electrode pedestal installed to maintain a constant level outside the furnace body at a position corresponding to directly below the electrode when the furnace lid is opened in an arc furnace, and the elevation position of the electrode holder. and an arithmetic controller that inputs the detection signal from the position detector, calculates the length under the neck and the amount of wear of the electrode, and outputs a control signal according to the amount of wear. An electrode length adjustment device for an arc furnace, characterized by comprising: