Converter Inversion for Uniform Charge Preheating
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Solution Overview
Problem
The existing methods for producing steel using lumpy iron carriers in a converter fail to achieve uniform distribution of hot fuel gases, limiting the preheating temperature and the proportion of scrap iron that can be used due to nozzle placement and vertical flow channels formed by the gases.
Innovation Solution
The converter is rotated to a preheating position with the bottom pointing upwards, allowing fuel and oxidizing gases to be injected through nozzles into a combustion chamber above the charge, creating overpressure for uniform gas flow and eliminating top heat losses, enabling efficient preheating of the charge with combustion gases flowing from top to bottom.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If fuel and oxidizing gas are injected through nozzles in the converter bottom, then the charge material can be preheated, but the hot fuel gases form vertical flow channels that prevent uniform distribution across the charge cross-section
Solution Approach 1:
The converter is inverted (rotated 180 degrees) during the preheating operation. The converter bottom is positioned upward and the converter opening downward, allowing combustion gases to flow upward through the charge material rather than downward. This inversion eliminates vertical flow channeling and achieves uniform gas distribution across the entire charge cross-section.
Solution Approach 2:
By inverting the converter, the direction of gas flow is changed from vertical (top-to-bottom) to upward flow (bottom-to-top). This dimensional change in flow direction prevents the formation of vertical flow channels and enables uniform distribution of combustion gases across the charge material.
2Ease of manufacture
If nozzles are positioned in a limited central area of the converter bottom, then the nozzle placement is feasible, but the combustion gases cannot be distributed over a larger cross-sectional area of the feed material
Solution Approach 1:
Inverting the converter allows the limited central nozzles to distribute gases upward across the entire charge cross-section. The inversion transforms the limitation into an advantage by utilizing the upward flow to naturally distribute gases across the full area of the charge material.
Solution Approach 2:
The inverted converter configuration acts as an intermediary mechanism that transforms the localized nozzle placement into widespread gas distribution. The upward flow path and charge material configuration serve as intermediaries to expand the distribution area beyond the nozzle locations.
3Ease of operation
If the converter is operated with bottom-mounted nozzles, then the charging process is simple, but heat losses through the converter opening cannot be eliminated
Solution Approach 1:
The converter is inverted during preheating, positioning the thick converter bottom upward to provide thermal insulation at the top opening. This inversion eliminates heat losses through the opening while maintaining operational simplicity through the same charging mechanism.
Solution Approach 2:
The converter bottom structure serves as a thermal insulation intermediary when positioned upward. It blocks heat loss through the opening while allowing the preheating process to continue, effectively mediating between operational simplicity and energy conservation.
4Manufacturing precision
If the preheating time is extended to heat feed material uniformly, then the temperature distribution improves, but the production time increases
Solution Approach 1:
Inverting the converter during preheating creates upward flow conditions that significantly improve temperature uniformity across the charge. This configuration achieves uniform heating much faster than conventional bottom-blown methods, reducing preheating time while maintaining temperature uniformity.
Solution Approach 2:
The inversion changes the flow direction parameter, transforming the preheating process from inefficient vertical channeling to efficient upward distribution. This parameter change accelerates heat transfer and achieves uniform temperature distribution more rapidly.
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 allows for significantly increased use of lumpy iron carriers by ensuring uniform heating and reducing heat losses, thereby enhancing the efficiency of steel production and increasing the proportion of scrap iron used in the process.
Implementation Method 1
fuel and oxidizing gas are injected through nozzles in the area of the converter bottom into a combustion chamber opening between the charge material and the converter bottom
Implementation Method 2
the combustion gases flowing through the charge material are discharged through the grate
Implementation Method 3
build up overpressure. This overpressure ensures a uniform flow of the combustion gases from top to bottom across the entire cross-section of the feed material
Implementation Method 4
the combustion gases, which occupy a significantly larger volume due to the combustion process, are distributed throughout this combustion chamber and, in conjunction with the flow resistance caused by the feed material, build up overpressure
Implementation Method 5
Since the converter is thermally insulated from above by its base in this preheating position, the heat losses that would otherwise be unavoidable through the converter opening are eliminated
Data Source
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Figure 3
AI summary
The invention relates to a method for producing steel using lump iron carriers in a converter (1). Fuel and oxidizing gas are injected into the hot converter (1) supplied with lump iron carriers through nozzles (4) in the converter base (3), and the hot combustion gases are conducted through the supplied material (12) before molten iron is supplied to the preheated supplied material (12) and the molten iron is refined into steel. For preheating purposes, the converter (1) supplied with lump iron carriers is rotated out of a supply position into a preheating position, in which the converter base (3) points upwards, after the converter opening (8) is closed by a grate (13) before the fuel and the oxidizing gas are injected into the combustion chamber (15) formed above the supplied material (12) through the nozzles (4) and the combustion gases flowing through the supplied material (12) are discharged through the grate (13). After the supplied material (12) is preheated, the converter (1) is returned to the supply position and the converter opening (8) is opened in order to supply the molten iron.