Bottom-Blowing Nozzle Mushroom Head Control Against Erosion and Blockage

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Solution Overview

Problem

The rapid erosion of the bottom-blowing nozzle in steelmaking processes due to the mushroom head formation is a challenge, as the size and shape of the mushroom head significantly impact the nozzle's lifespan, and existing methods fail to dynamically adjust to the changing conditions during the steelmaking process.

Innovation Solution

A method that dynamically adjusts the oxygen, carbon dioxide, and lime powder blowing parameters based on the mushroom head state coefficient and molten steel overheating degree, using carbon dioxide to replace oxygen after lime powder spraying to maintain the mushroom head size and reduce carbon dioxide consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the mushroom head size is increased to protect the bottom blowing nozzle, then the erosion resistance is improved, but the nozzle blockage risk increases

Engineering Contradiction:
Improvenozzle erosion resistanceVSAvoidnozzle blockage risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent implements dynamic control of the mushroom head size by adjusting blowing parameters in real-time based on the steelmaking process stage. The system transitions from a static mushroom head approach to a dynamic one where the size and shape are continuously optimized to maintain protection while preventing blockage.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes physical parameters including oxygen flow rate, carbon dioxide flow rate, and lime powder injection amount to control mushroom head characteristics. By adjusting these parameters dynamically, the system optimizes the balance between erosion protection and blockage prevention.

Inventive Principle:
Principle #35Parameter changes

2Temperature

If carbon dioxide blowing intensity is increased to cool the bottom-blowing nozzle, then the nozzle temperature is reduced, but the heat loss of the converter increases

Engineering Contradiction:
Improvenozzle temperatureVSAvoidconverter heat loss
Core Design Contradiction:
TemperatureVSLoss of energy

Solution Approach 1:

The patent applies cooling locally at the nozzle position using carbon dioxide injection rather than cooling the entire converter. This localized approach reduces nozzle temperature while minimizing overall heat loss from the converter system.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent utilizes the exothermic reaction of carbon dioxide with molten steel to generate heat that compensates for the cooling effect, thereby maintaining nozzle temperature control while minimizing converter heat loss. The reaction heat converts the potential harm of cooling into a beneficial heat source.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Reliability

If lime powder blowing amount is increased to improve metallurgical reaction, then the impurity removal is enhanced, but the mushroom head growth control becomes difficult

Engineering Contradiction:
Improvemetallurgical reaction efficiencyVSAvoidmushroom head size stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent implements feedback control by monitoring the mushroom head state coefficient and adjusting lime powder injection accordingly. The system uses the ratio of gas flow rate to pressure as feedback to maintain optimal mushroom head size while ensuring adequate metallurgical reaction.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent creates a composite blowing system combining oxygen, carbon dioxide, and lime powder in specific proportions. This composite approach allows simultaneous optimization of metallurgical reaction and mushroom head control through coordinated parameter adjustment.

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

Effectively stabilizes the mushroom head size, reducing carbon dioxide usage while enhancing corrosion resistance and extending the nozzle's lifespan by up to 500 furnaces compared to traditional methods.

Implementation Method 1

both lime powder and carbon dioxide have the effect of cooling the bottom-blowing nozzle

Methodology Applied
Scientific EffectEndothermic reaction: Endothermic Reaction

Implementation Method 2

The mushroom head at the end of the bottom blowing nozzle is formed by condensation of molten steel

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 3

both lime powder and carbon dioxide have the effect of cooling the bottom-blowing nozzle

Methodology Applied
Scientific EffectEndothermic reaction: Endothermic Reaction

Data Source

PatentUS12571061B2Blowing control method for maintaining mushroom head of bottom-blowing nozzle converter
Publication Date: 2026.03.10 SUZHOU UNIV

AI summary

A blowing control method for maintaining a mushroom head of a bottom-blowing nozzle converter is disclosed. Considering the actual state of the mushroom head at the end of the bottom-blowing nozzle tip, the real-time molten steel overheating change during the blowing process, the process requirements of different stages of blowing conversion, and the macroscopic heat balance of the converter, the oxygen-carbon dioxide-lime powder blowing parameters of the inner tube of the bottom-blowing nozzle are dynamically adjusted during the converter smelting process of the bottom-blowing nozzle converter so as to control the cooling intensity, thus achieving precise control of the size of the mushroom head. The present invention maintains the basic stability of the size of the mushroom head at the end of the bottom-blowing nozzle tip, avoiding nozzle blockage caused by an oversized mushroom head and rapid erosion of the nozzle caused by an undersized mushroom head.