Direct Reduction Gas Bypass for Flexible Hot DRI Production
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Solution Overview
Problem
Existing direct reduction systems require complex layouts for cooling, transport, and storage of cold DRI when the melting furnace is halted, leading to increased energy consumption and operational inefficiencies.
Innovation Solution
A direct reduction system with a bypass duct and regulation valves to adjust reducing gas flow based on melting furnace demands, allowing flexible production rates without diverting hot DRI, thus simplifying the system layout and maintaining high-energy efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the melting furnace is halted for maintenance or production reasons, then the direct reduction system must divert hot DRI to external cooling systems, but this increases system complexity and energy consumption
Solution Approach 1:
The patent applies dynamics by making the reducing gas flow adjustable rather than fixed. A regulation valve is introduced in the reducing gas feeding line to dynamically control the flow rate of reducing gas to the reactor based on the melting furnace's production demands. This allows the system to adapt production rates without requiring complex cooling and storage infrastructure for cold DRI.
2Productivity
If hot DRI is diverted to external cooling systems, then production continuity is maintained, but energy consumption increases due to cooling and subsequent reheating
Solution Approach 1:
The patent applies parameter changes by modifying the flow rate parameter of reducing gas to the reactor. By adjusting this parameter through the regulation valve, the system can match production output to melting furnace demand without diverting hot DRI to cooling systems. This maintains productivity continuity while avoiding the energy waste associated with cooling and reheating cycles.
3Reliability
If the reducing gas flow rate is fixed, then the heating unit operates at constant capacity, but the system cannot adapt to varying melting furnace production requirements
Solution Approach 1:
The patent applies segmentation by dividing the reducing gas flow control into two independent paths: a main feeding line with a regulation valve for adjustable flow control, and a bypass line that can operate independently. This segmentation allows the system to regulate DRI production rate while maintaining stable operation of the heating unit, as the bypass can compensate for flow variations.
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
Enables flexible production rates, reduces energy consumption, and eliminates the need for cooling and storage systems, ensuring hot DRI is always available for the melting furnace, enhancing operational efficiency and environmental impact.
Implementation Method 1
the oxygen is removed from the iron ore by means of chemical reactions with hydrogen and carbon monoxide, so as to obtain DRI with a high degree of metallization
Implementation Method 2
Fe2O3+3H2−>2Fe+3H2O (1) Fe2O3+3CO−>2Fe+3CO2 (2)
Implementation Method 3
The gas flow is sent to a heating unit which brings it to the temperature required by the reduction process, usually over 850° C
Implementation Method 4
the oxygen is injected so as to further increase the temperature thereof
Data Source
AI summary
A direct reduction system for a direct reduction of iron ore, comprising a reactor having a reduction area and being adapted to be loaded from above with said iron ore; a treatment and feeding line, to process the process gases, thus obtaining a reducing gas mixture, and feed said reducing gas mixture into the reduction area; a line for recovering and treating an exhausted gas exiting the reactor, communicating upstream with the reactor and downstream with said treatment and feeding line; wherein at least one bypass duct is provided, adapted to divert at least one portion of reducing gas mixture from said treatment and feeding line to said recovery and treatment line.