Consumable Cored Wire Structure for Molten Steel Temperature Sensing

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Solution Overview

Problem

Existing consumable optical fibers for measuring molten metal temperatures suffer from rapid deterioration due to devitrification and lack of reliable exposure mechanisms, limiting their applicability to a wide range of metallurgical vessels without customization.

Innovation Solution

A consumable cored wire with a multi-layered structure comprising a metal jacket, a thermal insulating intermediate layer of gas-porous fibers, and a central optical fiber, where the intermediate layer fluidizes and flows away from the optical fiber, exposing a fresh surface for accurate temperature measurement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the optical fiber is directly exposed to the molten steel bath without sufficient protection, then the temperature measurement function is improved, but the optical fiber is damaged by the molten steel

Engineering Contradiction:
Improvetemperature measurementVSAvoidoptical fiber damage
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The optical fiber is nested within multiple protective layers including an inner sheath, metal tube, and outer sheath, creating a nested structure that protects the fragile optical fiber while allowing it to function in the harsh molten steel environment

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

Multiple intermediate protective layers (inner sheath material, metal tube, outer sheath) are introduced as mediators between the optical fiber and the molten steel bath, allowing the optical fiber to measure temperature without direct contact with the damaging molten steel

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a complex multi-layer protective structure is used to protect the optical fiber, then the protection function is improved, but the production complexity increases

Engineering Contradiction:
Improveoptical fiber protectionVSAvoidproduction complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The protective structure is segmented into distinct functional layers (inner sheath, metal tube, outer sheath), each with specific protective functions, allowing for standardized manufacturing of individual components that are then assembled into the complete protected optical fiber structure

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The protective structure uses composite materials combining different properties (polymer inner sheath for chemical resistance, metal tube for mechanical strength and thermal conductivity, polymer outer sheath for environmental protection), creating a unified protective system that leverages the strengths of each material

Inventive Principle:
Principle #40Composite materials

3Reliability

If the optical fiber is surrounded by multiple protective layers, then the protection against molten steel is improved, but the heat conduction to the optical fiber is reduced

Engineering Contradiction:
Improveprotection against molten steelVSAvoidheat conduction
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

Different layers of the protective structure have different thermal properties optimized for their specific functions: the metal tube provides high thermal conductivity for heat transfer to the optical fiber, while the polymer sheaths provide thermal insulation and chemical resistance where needed

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The composite protective structure combines materials with different thermal conductivities (metal for high conduction, polymer for insulation) in a layered configuration that balances protection requirements with heat transfer needs, ensuring the optical fiber receives sufficient thermal energy for accurate measurement

Inventive Principle:
Principle #40Composite materials

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

The solution enables continuous production of cored wires up to several kilometers long, ensuring predictable and reliable temperature measurements in molten steel baths with minimal interruptions and improved worker safety.

Implementation Method 1

a consumable cored wire comprising an optical fiber surrounded by a cover for measuring a temperature of a molten steel bath

Methodology Applied
Scientific EffectOptical fiber temperature sensing: Optical Fibre

Data Source

PatentEP4242713B1Method of producing a consumable cored wire
Publication Date: 2026.05.06 HERAEUS ELECTRO NITE INT NV
  • EP4242713B1 patent drawingFigure 1~3
  • EP4242713B1 patent drawingFigure 3a~4
  • EP4242713B1 patent drawingFigure 4a~5

AI summary

The invention relates to a consumable cored wire comprising an optical fiber surrounded by a cover for measuring a temperature of a molten steel bath. The invention also refers to a method and a device for producing the cored wire. The object of the invention is to further improve a cored wire for measuring the temperature of molten steel. A cored wire comprises an optical fiber and a cover laterally surrounding the optical fiber. The cover surrounds the optical fiber in a plurality of layers. One layer is a metal pipe also called metal jacket or metal tube. An intermediate layer is arranged beneath the metal tube also called filler. The intermediate layer is a rope.