Laser Electrode Position Measurement in Electric Arc Furnaces

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Solution Overview

Problem

Existing systems for measuring the position of electrodes in electric arc furnaces are unreliable due to electromagnetic interference and exposure to liquids, oils, and powders, leading to system damage and failure, which hinders efficient energy transfer and process optimization.

Innovation Solution

A non-contact laser-based measurement system with high electromagnetic sound rejection, coupled with a reflector and digital or optical fibre transmission, installed in a protective environment to provide precise and reliable position data of the electrodes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If encoder-based position measurement systems are used, then measurement precision is improved, but reliability deteriorates due to electromagnetic interference and exposure to liquids, oils, and powders

Engineering Contradiction:
Improveposition measurement precisionVSAvoidsystem reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces mechanical encoder systems with a laser-based optical measurement system. The laser device emits laser beams that reflect off the electrode holder arm, and position is determined by analyzing the reflected beam characteristics. This substitution eliminates mechanical contact components that are vulnerable to electromagnetic interference and contamination from liquids, oils, and powders, thereby maintaining measurement precision while significantly improving system reliability in harsh industrial environments.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a reflector as an intermediary element between the laser device and the electrode holder arm. The reflector receives the laser beam and redirects it back to the detection system, enabling non-contact position measurement. This intermediary approach allows the measurement system to remain isolated from the harsh electromagnetic and chemical environment while still accurately tracking electrode position, resolving the contradiction between precision and reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If non-contact laser-based measurement systems are used, then reliability is improved, but device complexity increases due to additional components and protective infrastructure

Engineering Contradiction:
Improvesystem reliabilityVSAvoidmeasurement system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The laser device is designed to perform multiple functions: emitting laser beams for position measurement, serving as part of the measurement optical path, and integrating with the control system through standard interfaces. The reflector also serves dual purposes by both reflecting the laser beam and providing a mounting reference for the electrode holder arm. This multi-functionality reduces the need for separate dedicated components, thereby managing device complexity while maintaining high reliability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The measurement system is designed to be self-aligning and self-calibrating to a large extent. The laser beam automatically tracks the reflector on the moving electrode holder arm, and the system uses the reflected beam characteristics to directly calculate position without requiring complex external calibration procedures. This self-service capability reduces operational complexity and maintenance requirements, balancing the increased initial device complexity with long-term simplicity.

Inventive Principle:
Principle #25Self-service

3Productivity

If position measurement systems are implemented, then productivity is improved through process optimization, but loss of time occurs during installation and calibration

Engineering Contradiction:
Improveproduction efficiencyVSAvoidinstallation and calibration time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The laser device and reflector are pre-assembled as an integrated measurement unit that can be mounted on the electrode holder arm structure during initial furnace construction or maintenance shutdowns. The system comes pre-configured with alignment features and mounting interfaces, eliminating the need for time-consuming on-site calibration and alignment procedures. This preliminary preparation significantly reduces installation and calibration time while enabling continuous position measurement that improves production efficiency during furnace operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

By replacing complex mechanical encoder systems with the laser-based optical measurement system, the patent reduces the number of mechanical installation steps and calibration procedures. The laser system requires only basic optical alignment, which is far quicker and simpler than mechanical encoder installation. This substitution directly addresses the time loss during installation while delivering continuous reliable measurement that enhances overall productivity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables continuous, precise measurement of electrode position, optimizing energy transfer, reducing maintenance needs, and improving process efficiency by integrating position and current measurements, even in hostile environments.

Implementation Method 1

A non-contact laser-based measurement system

Methodology Applied
Scientific EffectLaser: Laser

Implementation Method 2

coupled with a reflector and digital or optical fibre transmission

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP2411750B1Apparatus for measuring the position of the electrodes in an electric furnace
Publication Date: 2019.07.24 TENOVA
  • EP2411750B1 patent drawingFigure 1~2

AI summary

An apparatus for measurinq the position of the electrodes in an electric furnace which envisages an electrode-holder column (10), comprising a lifting group (11), integral with a base structure (12) and carrying an electrode-holder arm (13) containing at least one electrode (14) immersed in a bath and/or in contact with scrap, said apparatus comprising at least one laser group (17) positioned on at least a part of the base structure (12) which collaborates with a reference element (18) integral with the at least one electrode (14).