Hot Charging Ironmaking with Hydrogen-Rich Gas
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Solution Overview
Problem
The iron and steel industry faces challenges in energy efficiency and emission reduction due to high energy consumption and CO2 emissions, particularly in the ironmaking process, where current methods for cooling and charging materials result in energy wastage and environmental pollution, and the use of cold materials in blast furnaces leads to insufficient thermal energy and increased carbon deposition.
Innovation Solution
A method and apparatus for ironmaking using full-oxygen hydrogen-rich gas, where coke, sinter, and pellet are hot transferred and charged into the furnace at high temperatures, utilizing oxygen and hydrogen-rich combustible gas for smelting, and regenerative heat exchangers to recover sensible heat, reducing the need for cooling devices and enhancing thermal energy distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If cold materials are charged into the blast furnace, then transportation and handling are easier, but thermal energy in the upper portion becomes insufficient and carbon deposition increases
Solution Approach 1:
The patent applies preliminary action by pre-heating the charging materials (coke, sinter, pellet) to high temperature (800-1200°C) before charging them into the blast furnace. This preliminary heating ensures that the materials possess sufficient thermal energy upon entry, eliminating the need for additional heating in the upper furnace and preventing carbon deposition. The hot charging process transforms the cold charging conventional operation into a thermally optimized process.
2Ease of operation
If coke is cooled to atmospheric temperature, then it is good for transportation and handling, but stress cracks are introduced and strength decreases
Solution Approach 1:
The patent maintains coke at high temperature (800-1200°C) from the coke oven through to charging, applying preliminary action by preparing the coke in advance at the optimal temperature for both strength maintenance and subsequent furnace performance. Specialized hot charging equipment is used to transport and charge the hot coke without cooling, thereby preserving coke strength while enabling continuous operation.
3Loss of energy
If sensible heat of hot materials is recovered through cooling apparatus, then energy can be utilized, but complex cooling devices are required and large space is occupied
Solution Approach 1:
The patent applies self-service by having the hot charging materials themselves serve as the heat source for pre-heating the charging air and gases within the furnace system. The hot coke, sinter, and pellet directly transfer their sensible heat to the surrounding environment during the charging process and early furnace stages, eliminating the need for separate cooling apparatus and large-scale heat recovery systems.
4Productivity
If pure oxygen smelting is used, then coke ratio is decreased and yield increases, but gas amount becomes insufficient and upper furnace temperature is low
Solution Approach 1:
The patent applies preliminary action by pre-heating the charging materials to high temperature (800-1200°C) before introduction to the blast furnace. This preliminary thermal preparation compensates for the absence of coke combustion heat in the upper furnace zones, maintaining sufficient temperatures for indirect reduction reactions to proceed effectively despite pure oxygen smelting conditions.
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 significantly reduces energy consumption, increases the metallic ratio of charges, improves indirect reduction efficiency, decreases CO2 emissions, and enhances the yield of molten iron, while eliminating stress cracks in coke and reducing dust pollution, thereby achieving energy savings and environmental benefits.
Implementation Method 1
Gas with high temperature and high heat value that is discharged from upper portion of the ironmaking furnace transfers the physical heat to hydrogen-rich combustible gas being injected into the furnace through regenerative heat exchanger
Implementation Method 2
hot transferring and hot charging of ironmaking raw material at high temperature
Implementation Method 3
injecting full-oxygen and hydrogen-rich combustible gas
Data Source
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AI summary
The present invention provides a method of ironmaking using full-oxygen hydrogen-rich gas which comprises hot transferring and hot charging the high-temperature coke, sinter and pellet into the ironmaking furnace (3) through transferring and charging device, and injecting oxygen and hydrogen-rich combustible gas at a predetermined temperature into the ironmaking furnace (3) through the oxygen tuyere and the gas tuyere disposed at the ironmaking furnace (3), respectively. It also provides an apparatus for ironmaking using full-oxygen hydrogen-rich gas which comprises a raw material system, a furnace roof gas system, a coke oven gas injecting system, a dust injecting system, a slag dry-granulation and residual heat recovering system and an oxygen system (11). Additionally, it further provides an apparatus and method for hot transferring and hot charging of ironmaking raw material.