Blowing Control for Converter Dephosphorization

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing blowing control methods for converter type dephosphorization refining furnaces fail to adequately monitor and control the FeO concentration in slag after desiliconization treatment, leading to decreased dephosphorization efficiency and rephosphorization phenomena due to increased molten iron temperature.

Innovation Solution

A blowing control method and apparatus that monitor the change in oxygen accumulation in the furnace, extract feature points to determine the optimal oxygen amount at the end of the blowing process, and adjust oxygen feed to maintain desired FeO concentrations in slag, thereby optimizing dephosphorization efficiency and reducing auxiliary material consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If excessive oxygen is fed to ensure dephosphorization treatment, then phosphorus removal is improved, but molten iron temperature increases causing decreased dephosphorization efficiency or rephosphorization

Engineering Contradiction:
Improvephosphorus removal amountVSAvoidmolten iron temperature
Core Design Contradiction:
Quantity of substanceVSTemperature

Solution Approach 1:

The patent implements feedback control by continuously monitoring the FeO concentration in slag during the blowing process and adjusting the oxygen supply rate accordingly. When FeO concentration reaches the predetermined range (3-10%), the oxygen supply is adjusted to maintain this concentration, preventing excessive temperature rise while ensuring adequate phosphorus removal.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes the control parameter from fixed oxygen supply rate to dynamic oxygen supply rate based on FeO concentration. By monitoring FeO concentration and adjusting oxygen supply in real-time, the system maintains optimal temperature and dephosphorization efficiency without excessive heat generation.

Inventive Principle:
Principle #35Parameter changes

2Quantity of substance

If oxygen supply is increased to maintain FeO concentration in slag, then dephosphorization efficiency is improved, but oxygen accumulation in furnace increases causing temperature rise

Engineering Contradiction:
ImproveFeO concentration in slagVSAvoidoxygen accumulation energy
Core Design Contradiction:
Quantity of substanceVSUse of energy by moving object

Solution Approach 1:

The system uses feedback control to monitor FeO concentration and adjust oxygen supply. When FeO concentration reaches the target range, the oxygen supply rate is reduced or stopped, preventing further oxygen accumulation and associated temperature rise, while maintaining adequate FeO levels for dephosphorization.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent transitions from static oxygen supply to dynamic oxygen supply that adapts to changing FeO concentration. The oxygen supply rate is continuously adjusted based on real-time FeO measurements, allowing the system to maintain optimal FeO levels without excessive oxygen accumulation.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If FeO concentration in slag is not monitored after desiliconization, then process simplicity is maintained, but dephosphorization efficiency decreases due to FeO depletion

Engineering Contradiction:
Improveprocess simplicityVSAvoiddephosphorization efficiency
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The patent introduces FeO concentration monitoring as a feedback mechanism during the dephosphorization stage. By measuring FeO concentration and using it to control oxygen supply, the system maintains adequate FeO levels for efficient phosphorus removal, improving dephosphorization efficiency while adding minimal operational complexity.

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 approach effectively reduces phosphorus concentration in molten iron post-dephosphorization and minimizes auxiliary material usage in subsequent decarburization processes by precisely controlling oxygen supply.

Implementation Method 1

dephosphorization treatment is a reaction by which the phosphorus in the molten iron is oxidized by FeO, and P2O5 that has been generated by this oxidation reaction reacts with CaO

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 2

feeding excessive oxygen may increase the molten iron temperature due to the heat of various oxidation reactions

Methodology Applied
Scientific EffectExothermic reaction: Exothermic Reaction

Data Source

PatentEP3943618B1Blowing control method and blowing control apparatus for converter type dephosphorization refining furnace
Publication Date: 2024.02.21 JFE STEEL CORP
  • EP3943618B1 patent drawingFigure 1
  • EP3943618B1 patent drawingFigure 2
  • EP3943618B1 patent drawingFigure 3

AI summary

A blowing control method for a converter type dephosphorization refining furnace according to the present invention includes: an in-furnace oxygen accumulation amount calculating step of calculating the amount of oxygen accumulated in a furnace, based on blowing conditions including the feed amount of oxygen and the charging amount of auxiliary material for a converter type dephosphorization refining furnace, measurement results of the converter type dephosphorization refining furnace including the flow rate and the component concentration of exhaust gas in the converter type dephosphorization refining furnace, and analytical values of components and the temperature of molten iron; a feature point extracting step of sequentially monitoring the change of the amount of oxygen accumulated in the furnace during a blowing treatment and extracting a feature point of fluctuations in the amount of oxygen accumulated in the furnace; a blow end oxygen amount determining step of determining the amount of oxygen at blow end until the blowing treatment is completed, based on the feature point extracted at the feature point extracting step; and a control step of completing the blowing treatment at the timing at which the accumulated feed amount of oxygen fed into the converter type dephosphorization refining furnace has reached the amount of oxygen at blow end determined at the blow end oxygen amount determining step.