Tundish Open Eye Detection via Light Intensity

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Solution Overview

Problem

The formation of Tundish Open Eyes (TOEs) during the casting of steel semi-finished products leads to re-oxidation of liquid steel, inclusion formation, and potential clogging of Submerged Entry Nozzles, resulting in quality issues and reduced productivity.

Innovation Solution

A method that uses a light intensity transmitter to detect the presence and size of TOEs by comparing measured light intensity to a baseline, with a regression model used to calculate the open-eye size and emit an alert when the size exceeds a predetermined threshold.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an operator manually inspects the tundish surface and adds powder when necessary, then the process is simple and flexible, but there is always a delay between open eye formation and powder addition, resulting in re-oxidation and inclusion formation

Engineering Contradiction:
Improvesteel qualityVSAvoiddelay in powder addition
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent replaces the manual visual inspection method with an optical measurement system using a light transmitter to detect open eyes. The light transmitter sends light through the tundish wall and detects changes in light intensity caused by the presence of open eyes, enabling automatic and continuous monitoring without human intervention.

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

Solution Approach 2:

The system enables self-monitoring of the tundish surface condition. The light transmitter continuously measures light intensity and automatically detects when an open eye forms, triggering alerts or automatic powder addition without requiring constant operator presence or manual inspection.

Inventive Principle:
Principle #25Self-service

2Measurement precision

If continuous monitoring of the tundish surface is implemented using optical sensors, then the detection speed and steel quality improve, but the device complexity and cost increase

Engineering Contradiction:
Improveopen eye detection accuracyVSAvoidmonitoring system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent exploits the optical property changes that occur when an open eye forms on the tundish surface. The light transmitter detects changes in light intensity (analogous to color changes) caused by the presence of open eyes, allowing for accurate detection without complex imaging systems.

Inventive Principle:
Principle #32Color changes

Solution Approach 2:

The monitoring function is segmented into discrete components: a light transmitter for optical measurement, a detection system for analyzing light intensity changes, and an alert or control system for responding to detected open eyes. This modular approach simplifies the overall system compared to using a complete video imaging and processing system.

Inventive Principle:
Principle #1Segmentation

3Productivity

If manual inspection is used, then the device complexity is low, but the productivity decreases due to frequent SEN clogging requiring process interruption

Engineering Contradiction:
Improvecasting productivityVSAvoiddetection system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system establishes a feedback loop where the light transmitter continuously monitors the tundish surface, the detection system analyzes light intensity changes to identify open eyes, and the alert or control system responds by triggering powder addition or operator awareness. This closed-loop feedback enables proactive prevention of SEN clogging rather than reactive response.

Inventive Principle:
Principle #23Feedback

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

This method enables early detection of TOEs, allowing for timely intervention to prevent re-oxidation and inclusion formation, thereby improving steel quality and extending the life of Submerged Entry Nozzles.

Implementation Method 1

a light intensity transmitter to detect the presence and size of TOEs by comparing measured light intensity to a baseline

Methodology Applied
Scientific EffectLight emission: Light

Data Source

PatentEP4263089B1Casting method and associated device
Publication Date: 2025.05.07 ARCELORMITTAL SA
  • EP4263089B1 patent drawingFigure 1~2B
  • EP4263089B1 patent drawingFigure 3~4
  • EP4263089B1 patent drawingFigure 5

AI summary

A method of casting a steel semi-product wherein a liquid steel is poured from a ladle to a tundish through a shroud comprising the steps of determining the light intensity emitted from the surface of the liquid steel in the tundish, detecting, based on said determined intensity, the presence of an open-eye at the surface of the liquid steel and emitting an alert towards an operator when an open-eye is detected.