Method and arrangement for measurement of electrode paste in an electrode column of an electric arc furnace

Patent metadata

Field	Value
Publication number	US-10401090-B2
Application number	US-201415107279-A
Country	US
Kind code	B2
Filing date	Dec 30, 2014
Priority date	Dec 30, 2013
Publication date	Sep 3, 2019
Grant date	Sep 3, 2019

Abstract

A method and an arrangement measures electrode paste in an electrode column of an electric arc furnace. The electrode column has a steel casing, is provided with a contact shoe ring, and is filled with electrode paste introduced from above and evolving from raw paste in the upper part of the steel casing to melted paste and to baked paste in the lower part of the electrode column. The level of the raw paste is determined with a laser beam transmitted by a first laser device. The level of the molten paste is determined with a laser beam transmitted by a second laser device. The data received from the laser devices is used for calculation of the distances of the levels of the raw paste and molten paste from the contact shoe ring.

First claim

The invention claimed is:

1. A method for measurement of electrode paste in an electrode column of an electric arc furnace, which electrode column comprises a steel casing surrounding and covering the electrode paste formed of a graphite-based material and said electrode column being provided with a contact shoe ring formed of contact shoe elements and placed in contact with the steel casing to conduct electric current to the electrode, in which method the electrode column is filled with electrode paste by introducing said paste from above into the steel casing, whereby the electrode paste evolves through different phases, ranging from raw paste in the upper part of the steel casing to melted paste in the area starting above the contact shoe ring and further to baked paste in the lower part of the electrode column below the contact shoe ring, said method comprising:
providing a plurality of laser devices comprising a first laser device and a second laser device on the top of the electrode column, said laser devices each transmitting laser beams downwards,
determining the level of the raw paste in the steel casing corresponding to the height of the paste cylinder in the steel casing with the laser beam transmitted by the first laser device,
determining the level of the molten paste in the steel casing with the laser beam transmitted by the second laser device, and
utilizing the data received from the laser devices for calculation of the distances of the levels of the raw paste and molten paste from the contact shoe ring.

2. The method for measurement of electrode paste according to claim 1 , further comprising:
providing a reference rod on the electrode column at a constant distance from the contact shoe ring,
determining the position of the reference rod with the laser beam transmitted by a third laser device to determine the relative position of the contact shoe ring, so that when the relative position of the contact shoe ring is known, the distances of the levels of the raw paste and molten paste in the steel casing from the contact shoe ring is calculated with the data received from the three laser devices.

3. An arrangement for measurement of electrode paste in an electrode column of an electric arc furnace, which electrode column comprises a steel casing surrounding and covering the electrode paste formed of a graphite-based material and said electrode column being provided with a contact shoe ring formed of contact shoe elements and placed in contact with the steel casing to conduct electric current to the electrode, whereby the electrode column is filled with electrode paste by introducing said paste from above into the steel casing, in which the electrode paste evolves through different phases, ranging from raw paste in the upper part of the steel casing to melted paste in the area starting above the contact shoe ring and further to baked paste in the lower part of the electrode column below the contact shoe ring, wherein
a plurality of laser devices comprising a first laser device and a second laser device is provided on the top of the electrode column to transmit laser beams downwards, so that
the laser beam from the first laser device is arranged to determine the level of the raw paste in the steel casing corresponding to the height of the paste cylinder in the steel casing,
the laser beam from the second laser device is arranged to determine the level of the molten paste in the steel casing, whereby
an automation system of the furnace uses the data received from the laser devices to calculate the distances of the levels of the raw paste and molten paste from the contact shoe ring.

4. The arrangement for measurement of electrode paste according to claim 3 , wherein
a reference rod is provided on the electrode column at a constant distance from the contact shoe ring,
a third laser device is provided for the determination of the position of the reference rod with the laser beam transmitted by said third laser device to determine the relative position of the contact shoe ring, whereby
the automation system of the furnace uses the position data of the reference rod to calculate the distances of the levels of the raw paste and molten paste in the steel casing from the contact shoe ring with the data received from the three laser devices.

Assignees

• Outotec Finland Oy

Inventors

• Ollila Janne

Classifications

• F27D11/08

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

• F27D21/02

  Observation or illuminating devices · CPC title

• H05B7/10 Primary

  Mountings, supports, terminals or arrangements for feeding or guiding electrodes · CPC title

• F27D19/00 Primary

  Arrangements of controlling devices · CPC title

• H05B7/09

  Self-baking electrodes, e.g. Söderberg type electrodes · CPC title