Method for detection of the loss of an electric arc furnace measurement reference

Patent metadata

Field	Value
Publication number	US-2016131428-A1
Application number	US-201514629948-A
Country	US
Kind code	A1
Filing date	Feb 24, 2015
Priority date	Nov 6, 2014
Publication date	May 12, 2016
Grant date	—

Abstract

An electric arc furnace (EAF) including a raw material container, a set of electrodes, a set of electrical potential transformers, and a reference signal verification device. The set of electrodes are configured to be controllably extended toward the raw material container. The set of electrical potential transformers are correspondingly coupled to the set of electrodes. The reference signal verification device is configured to carry out the steps of reading a reference signal value coming from the raw material container; comparing the reference signal value to an approximated value; and determining that there is a loss of the reference signal if the reference signal value is not within a predetermined amount of the approximated value.

First claim

What is claimed is:

1 . An electric arc furnace, comprising:
a raw material container; a set of electrodes configured to be controllably extended toward said raw material container; a set of electrical potential transformers correspondingly coupled to said set of electrodes; and a reference signal verification device couplable to said transformers, said device being configured to carry out the steps of:
reading a reference signal value coming from said raw material container;
comparing said reference signal value to an approximated value; and
determining that there is a loss of the reference signal if said reference signal value is not within a predetermined amount of said approximated value.

2 . The electric arc furnace according to claim 1 , wherein said approximated value is a threshold value.

3 . The electric arc furnace according to claim 2 , wherein said threshold value is 50 volts.

4 . The electric arc furnace according to claim 1 , further comprising the step of approximating what a reference signal value should be dependent upon electrical values measured on said electrodes resulting in said approximated value;

5 . The electric arc furnace according to claim 4 , wherein said electrical values measured is a phase angle difference between said electrodes.

6 . The electric arc furnace according to claim 4 , wherein said electrical values measured have a symmetry in the phase differences between the electrodes indicating that the reference signal is verified.

7 . The electric arc furnace according to claim 6 , wherein said symmetry in the phase differences indicates that the reference signal is verified.

8 . A reference signal verification device to verify a reference signal coming from an electric arc furnace having electrodes and potential transformers, the device comprising:
a controller configured to carry out the steps of:
reading a reference signal value coming from the electric arc furnace;
comparing said reference signal value to an approximated value; and
determining that there is a loss of the reference signal if said reference signal value is not within a predetermined amount of said approximated value.

9 . The reference signal verification device according to claim 8 , wherein said approximated value is a threshold value.

10 . The reference signal verification device according to claim 9 , wherein said threshold value is 50 volts.

11 . The reference signal verification device according to claim 8 , further comprising the step of approximating what a reference signal value should be dependent upon electrical values measured on the electrodes resulting in said approximated value;

12 . The reference signal verification device according to claim 11 , wherein said electrical values measured is a phase angle difference between said electrodes.

13 . The reference signal verification device according to claim 11 , wherein said electrical values measured have a symmetry in the phase differences between the electrodes indicating that the reference signal is verified.

14 . The reference signal verification device according to claim 13 , wherein said symmetry in the phase differences indicates that the reference signal is verified.

15 . A method for detecting the loss of a reference signal associated with an electric arc furnace, the method comprising the steps of:
contacting raw material in a container with an electrode, said electrode being one of multiple electrodes; reading a reference signal value; comparing said reference signal value to an approximated value; and determining that there is a loss of the reference signal if said reference signal value is not within a predetermined amount of said approximated value.

16 . The method according to claim 15 , wherein said approximated value is a threshold value.

17 . The method according to claim 16 , wherein said threshold value is 50 volts.

18 . The method according to claim 15 , further comprising the step of approximating what a reference signal value should be dependent upon electrical values measured on said electrodes resulting in said approximated value;

19 . The method according to claim 18 , wherein said electrical values measured is a phase angle difference between said electrodes.

20 . The method according to claim 18 , wherein said electrical values measured have a symmetry in the phase differences between the electrodes indicating that the reference signal is verified.

Assignees

• Sgl Carbon Se

Inventors

• Bryant Billy

Classifications

• H05B7/144

  Power supplies specially adapted for heating by electric discharge; Automatic control of power, e.g. by positioning of electrodes · CPC title

• F27B3/28 Primary

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

• F27B3/085

  Arc furnaces · CPC title

• H05B7/18

  Heating by arc discharge · CPC title

• Y02P10/25

  Process efficiency · CPC title