Molten Metal Component Estimation via Exhaust Gas Correction

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Solution Overview

Problem

Existing methods for estimating molten metal component concentrations in steel refining processes suffer from inaccuracies due to large measurement errors in exhaust gas flow rates and component concentrations, leading to deviations in FeO concentration calculations and suboptimal operating conditions.

Innovation Solution

A molten metal component estimation device that uses input measurement results, a model database, and correction calculation units to minimize errors in flow rate and component concentration measurements, enabling continuous and accurate estimation of molten metal and slag compositions by calculating correction parameters for exhaust gas flow rates and component concentrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If exhaust gas flow rate and component concentration measurements are used to estimate molten metal component concentrations, then real-time estimation capability is achieved, but measurement errors are large leading to poor estimation accuracy

Engineering Contradiction:
Improvereal-time estimation capabilityVSAvoidestimation accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent implements a feedback mechanism where in-blow sampling results (direct molten metal analysis) are used to correct and update the estimation model. The system continuously compares estimated values with actual sampling values and adjusts the estimation algorithm accordingly, thereby improving accuracy while maintaining real-time capability.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent introduces an intermediary correction mechanism using in-blow sampling as a mediator between the indirect exhaust gas measurement method and the direct molten metal analysis. This intermediary sampling allows calibration of the estimation model without requiring continuous direct molten metal sampling.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If in-blow sampling is performed to correct estimation errors, then estimation accuracy is improved, but execution timing deviates from target values causing operational delays

Engineering Contradiction:
Improveestimation accuracyVSAvoidoperational timing delay
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent performs preliminary estimation using the physical model and exhaust gas data before in-blow sampling is available. This allows the system to provide initial guidance for sampling timing and operational decisions without waiting for the sampling results, thereby reducing operational delays.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements dynamic adjustment of the estimation system that adapts based on the timing and availability of in-blow sampling results. The system dynamically weights the contribution of different data sources (exhaust gas measurements vs. in-blow sampling) based on the current process stage and data availability, optimizing both accuracy and responsiveness.

Inventive Principle:
Principle #15Dynamics

3Device complexity

If physical reaction models are used to calculate FeO concentration and decarburization rate, then theoretical framework is established, but model values deviate from true values due to unknown disturbances

Engineering Contradiction:
Improvetheoretical modeling capabilityVSAvoidmodel calculation accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent dynamically adjusts model parameters based on in-blow sampling results and process conditions. Instead of using fixed model parameters, the system updates key parameters (such as reaction rates, mass transfer coefficients) based on actual measurements, allowing the model to adapt to unknown disturbances and changing process conditions.

Inventive Principle:
Principle #35Parameter changes

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 allows for precise and continuous estimation of molten metal and slag component concentrations, improving the accuracy of FeO concentration calculations and enabling the production of molten metal with desired properties at high yield.

Implementation Method 1

an intense oxidation reaction occurs in the molten metal and the temperature of the molten metal becomes very high

Methodology Applied
Scientific EffectOxidation reaction: Oxidation

Data Source

PatentEP3770279B1Molten metal component estimation device, molten metal component estimation method, and molten metal production method
Publication Date: 2022.08.10 JFE STEEL CORP
  • EP3770279B1 patent drawingFigure 1
  • EP3770279B1 patent drawingFigure 2
  • EP3770279B1 patent drawingFigure 3

AI summary

A molten metal component estimation device according to the present invention includes a material input-output calculation unit that estimates an amount of carbon and an amount of oxygen charged into a refining facility and an amount of carbon and an amount of oxygen discharged from the refining facility, a physical reaction model calculation unit that estimates at least one of an amount of oxygen and an amount of carbon remaining in the refining facility, and a correction calculation unit that calculates a parameter for correcting a measurement value of a flow rate of an exhaust gas, a parameter for correcting a measurement value of a component concentration of the exhaust gas, a parameter for correcting a calculation value of an FeO concentration in a slag, and a parameter representing the amount of carbon in the molten metal as first, second, third, and fourth correction parameters, respectively, and uses the calculated first, second, third, and fourth correction parameters to estimate component concentrations in the molten metal and the slag.