Mobile Furnace Gas-Circuit Layout for Continuous Direct Reduction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for producing direct reduced metal, particularly direct reduced iron, face challenges in scalability, flexibility, and cost-effectiveness when transitioning from batch-wise production to larger-scale operations, necessitating a more automatable and robust process that can handle fluctuating output requirements.

Innovation Solution

A continuous production method and system utilizing mobile furnaces that move between different gas stations for heating, reduction, cooling, and other processing steps, employing closed-loop gas circuits with separate valve systems for hydrogen and inert gases, and external heating/cooling units to maintain efficiency and flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If batch-wise production methods are used for direct reduced metal, then production simplicity is maintained, but productivity and scalability are limited

Engineering Contradiction:
Improveproduction capacityVSAvoidprocess complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The production system is segmented into multiple independent mobile furnaces that can operate in parallel. Each furnace is a self-contained unit with standardized gas connections, allowing the system to scale by simply adding more furnaces rather than redesigning the entire system. This segmentation enables progressive capacity expansion while maintaining operational simplicity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The furnaces are designed to be mobile rather than stationary, equipped with wheels or movable mounting systems. This dynamic design allows furnaces to be easily repositioned, connected to different gas circuits, or taken offline for maintenance without disrupting the entire production system, thereby enhancing both productivity and operational flexibility.

Inventive Principle:
Principle #15Dynamics

2Productivity

If production scaling is achieved by using multiple parallel furnaces, then productivity increases, but system complexity and coordination difficulty increase

Engineering Contradiction:
Improveproduction outputVSAvoidoperational management
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

All furnaces use standardized gas connection interfaces and identical operational procedures regardless of their position in the system. The universal design means that operators manage each furnace in the same way, and gas distribution can be routed to any furnace through a standardized valve system, simplifying coordination and reducing training requirements.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

Each mobile furnace is equipped with its own gas connection valves and control mechanisms, allowing individual furnaces to be independently operated and maintained. This self-service capability means that one furnace can be serviced or adjusted without affecting the operation of other furnaces, reducing coordination complexity while maintaining high overall productivity.

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If stationary furnaces are used for direct reduction, then structural stability is maintained, but flexibility and adaptability to changing production requirements are reduced

Engineering Contradiction:
Improveproduction flexibilityVSAvoidprocess stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The furnaces are designed with mobile mounting systems that provide both movement capability and operational stability. When positioned at a gas connection station, each furnace maintains stable processing conditions equivalent to stationary furnaces, but can be relocated when production requirements change, achieving both flexibility and reliability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system provides different operational characteristics at different locations: furnaces positioned at gas connection stations experience stable, controlled conditions for reliable reduction, while the overall system maintains flexibility through the ability to reposition furnaces between stations or take them offline, with each location optimized for its specific function.

Inventive Principle:
Principle #3Local quality

4Extent of automation

If automated production systems are implemented, then labor costs decrease and consistency improves, but initial investment and system complexity increase

Engineering Contradiction:
Improveproduction automationVSAvoidsystem complexity
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

Automation is implemented at the individual furnace level rather than as a centralized complex system. Each mobile furnace can be equipped with independent automation controls for gas valve management and processing parameters, allowing gradual automation adoption that reduces initial investment while improving consistency through standardized control procedures across all furnaces.

Inventive Principle:
Principle #1Segmentation

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 scalable, flexible, and cost-effective production of direct reduced metal by optimizing gas flow and temperature control, reducing maintenance needs, and enhancing production capacity through modular furnace design and parallel operation of heating/cooling stations.

Implementation Method 1

providing heated hydrogen gas to the mobile furnace so that the metal material is reduced by the heated hydrogen gas circulating past the metal material inside the mobile furnace

Methodology Applied
Scientific EffectReduction: Reduction

Implementation Method 2

providing heated inert gas to the mobile furnace so that the metal material is heated by the heated inert gas circulating past the metal material inside the mobile furnace

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

providing cooled inert gas to the mobile furnace so that the metal material is cooled by the cooled inert gas circulating past the metal material inside the mobile furnace

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP4305214B1Method and system for producing direct reduced metal
Publication Date: 2025.12.10 GREENIRON H2 AB
  • EP4305214B1 patent drawingFigure 1
  • EP4305214B1 patent drawingFigure 2
  • EP4305214B1 patent drawingFigure 3

AI summary

43 Abstract Method for producing direct reduced metal material (106) in a continuous process, wherein hydrogen gas and inert gas is circulated in respective closed-loop first and second gas circuits via different respective gas connection stations (130,140120-122,150-151), 5 comprising for individual mobile furnaces (101): a) charging metal material (106) into the furnace; b) moving and connecting the furnace to an inert gas connection station; c) providing heated inert gas to the furnace; d) disconnecting the furnace; 10 e) moving and connecting the furnace to a hydrogen gas connection station; f) providing heated hydrogen gas to the furnace; g) disconnecting the furnace; h) moving and connecting the furnace to an inert gas connection station; i) providing cooled inert gas to the furnace; 15 j) disconnecting the furnace; and k) discharging the metal material. The invention also relates to a system.