Open arc condition mitigation based on measurement

Patent metadata

Field	Value
Publication number	US-2020041208-A1
Application number	US-201816499708-A
Country	US
Kind code	A1
Filing date	Jan 22, 2018
Priority date	Mar 31, 2017
Publication date	Feb 6, 2020
Grant date	—

Abstract

A system measures parameters of the electricity drawn by an arc furnace and, based on an analysis of the parameters, provides indicators of whether arc coverage has been optimized. Factors related to optimization of arc coverage include electrode position, charge level, slag level and slag behaviour. More specifically, such indicators of whether arc coverage has been optimized may be used when determining a position for the electrode such that, to an extent possible, a stable arc cavity is maintained and an open arc condition is avoided. Conveniently, by avoiding open arc conditions, the internal linings of the furnace walls and roof may be protected from excessive wear and tear.

First claim

What is claimed is:

1 . A system comprising:
an analyzer adapted to:
receive a signal representative of an electrical signal measurement of the electrical power provided to an electric arc furnace; and
analyze the signal to determine, by analyzing the electrical signal measurement, a characteristic electrical parameter;
a first control unit adapted to:
receive the characteristic electrical parameter;
determine, based upon the electrical characteristic parameter, a change in operation for the electric arc furnace; and
transmit, to a second control unit provided for the electric arc furnace, an indication of the change.

2 . The system of claim 1 wherein the electrical signal measurement comprises a voltage measurement.

3 . The system of claim 2 wherein the electrical parameter comprises a voltage characteristic parameter.

4 . The system of claim 3 wherein the voltage characteristic parameter comprises voltage harmonics.

5 . The system of claim 3 wherein the voltage characteristic parameter comprises voltage fluctuation.

6 . The system of claim 1 wherein the electrical signal measurement comprises an electrical current measurement.

7 . The system of claim 6 wherein the electrical parameter comprises a parameter characteristic of current harmonics.

8 . A method comprising:
receiving a characteristic electrical parameter related to operation of an electric arc furnace; determining, based upon the characteristic electrical parameter, a change in operation for the electric arc furnace, where the change is related to mitigating an open arc condition; and transmitting, to a control unit provided for operation of the electric arc furnace, an indication of the change.

9 . The method of claim 8 wherein the characteristic parameter comprises an indication of a harmonic of a current waveform of the electrical power provided to the electric arc furnace.

10 . The method of claim 8 wherein the characteristic parameter comprises an indication of a harmonic of a voltage waveform of the electrical power provided to the electric arc furnace.

11 . The method of claim 8 wherein the change in operation for the electric arc furnace comprises a current set point offset.

12 . The method of claim 8 wherein the characteristic parameter comprises an indication of fluctuations in the voltage of the electrical power provided to the electric arc furnace.

13 . The method of claim 12 further comprising extracting an indication of a flicker in the voltage.

14 . The method of claim 8 wherein the change in operation for the electric arc furnace comprises an electrode position offset.

15 . The method of claim 8 wherein the change in operation for the electric arc furnace comprises a voltage set point offset

16 . The method of claim 8 wherein the change in operation for the electric arc furnace comprises a power set point offset.

17 . The method of claim 8 wherein the change in operation for the electric arc furnace comprises a change in feed rate.

18 . A method of open arc detection, the method comprising:
obtaining an electrical signal measurement; detecting, based upon the electrical signal measurement, an open arc condition; determining, based upon the electrical signal measurement, a change in operation for the electric arc furnace, where the change is related to ending the open arc condition; and transmitting, to a control unit associated with operation of the electric arc furnace, an indication of the change.

19 . The method of claim 18 further comprising coordinating, based upon the detecting, feed control in a non-ferrous Electrical Arc Furnace to maintain a preferred arc cover.

20 . The method of claim 18 further comprising coordinating, based upon the detecting, the carbon and oxygen injection in a scrap steel Electrical Arc Furnace to maintain a preferred arc cover.

21 . The method of claim 18 further comprising coordinating, based upon the detecting, the slag and foam thickness in an Electrical Arc Furnace to maintain a preferred arc cover.

Assignees

• Hatch Ltd

Inventors

• Shen Dong
• Campbell Michael Morgan
• Hawthorne Steven Robert

Classifications

• F27D21/00

  Arrangement of monitoring devices; Arrangement of safety devices · CPC title

• F27D11/08

  Heating by electric discharge, e.g. arc discharge · CPC title

• H05B7/148

  Automatic control of power (electrode feeding arrangements H05B7/109; automatic feeding of electrodes for spot or seam welding or cutting B23K9/12; disposition of electrodes in or on furnaces F27D11/10; control of position in general G05D3/00; regulating electric characteristics of arcs in general G05F1/02; regulating electric power in general G05F1/66) · CPC title

• F27B3/28 Primary

  Arrangement of controlling, monitoring, alarm or the like devices · CPC title

• F27D19/00 Primary

  Arrangements of controlling devices · CPC title