Direct Reduction Reactor Steel-Plate Lining for Hydrogen Corrosion
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Solution Overview
Problem
Silicate-containing refractory linings in direct reduction reactors are susceptible to hydrogen-induced corrosion, leading to weight and strength loss, and volatile SiO deposits that can damage the reactor or sponge iron production.
Innovation Solution
Incorporating steel plates into the inner lining of direct reduction reactors, particularly in sections exposed to hydrogen, to protect the refractory material and prevent corrosion, while also providing wear resistance against abrasive iron carriers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If silicate-containing refractory linings are used in direct reduction reactors, then the reactor can operate at high temperatures, but the refractory material is susceptible to hydrogen-induced corrosion leading to weight and strength loss
Solution Approach 1:
The patent applies composite materials by combining steel plates with refractory lining materials to create a hybrid protective structure. The steel plates form an outer protective layer that resists hydrogen corrosion, while the inner refractory lining maintains high-temperature stability. This composite approach allows the system to operate at high temperatures (17) while preventing hydrogen-induced corrosion (27) that would otherwise degrade the refractory material alone.
Solution Approach 2:
The steel plates serve as an intermediary protective layer between the hydrogen-based reducing gas and the refractory lining. This intermediate steel barrier absorbs the harmful hydrogen corrosion effects, protecting the underlying refractory material from direct exposure to hydrogen. The steel plates act as a mediator that shields the refractory material while allowing the high-temperature operating conditions to be maintained.
2Strength
If silicate-containing refractory linings are used in direct reduction reactors, then the reactor can maintain structural integrity at high temperatures, but volatile SiO forms and causes clogging or damage to the reactor and sponge iron
Solution Approach 1:
The composite structure of steel plates combined with refractory lining prevents the formation of volatile SiO by protecting the refractory material from hydrogen corrosion. The steel outer layer eliminates the chemical reaction between hydrogen and silicate-containing refractory materials, thereby preventing the generation of volatile SiO that would otherwise cause clogging and damage to the reactor and sponge iron production.
Solution Approach 2:
The steel plates function as an intermediary barrier that prevents the harmful chemical reaction between hydrogen and silicate-containing refractory materials. This intermediate layer blocks the formation pathway for volatile SiO, eliminating the source of clogging and damage while allowing the refractory lining to maintain its structural integrity at high temperatures.
3Reliability
If steel plates are arranged on the inner lining to protect against hydrogen corrosion, then hydrogen-induced corrosion is reduced, but the device complexity increases
Solution Approach 1:
The protective structure is segmented into distinct components: steel plates arranged in sections on the inner lining. This segmentation allows for modular installation and maintenance, where individual steel plates can be replaced or adjusted without removing the entire refractory lining. The segmented approach protects against hydrogen corrosion (27) while managing device complexity (36) through standardized, replaceable components.
Solution Approach 2:
The steel plates are arranged locally on the inner lining in specific sections where hydrogen corrosion is most severe, rather than requiring complete coverage. This localized protection approach provides effective corrosion resistance (27) while minimizing the overall complexity (36) and material usage. The steel plates are positioned strategically in the reduction zone where hydrogen exposure is highest.
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
Reduces hydrogen-induced corrosion and abrasive wear, maintaining the integrity of the refractory lining and ensuring efficient sponge iron production.
Implementation Method 1
Silicate-containing linings—as commonly used (see also EP 3 891 454 B1)—are susceptible to hydrogen-induced corrosion. At high temperatures, SiO2 reacts with H2 to form volatile SiO as the main reaction product.
Implementation Method 2
At prevailing temperatures in the direct reduction reactor, for example, of 600 to 1100 °C, the use of a steel material is ideally suited, as it is essentially temperature-stable in this range and, depending on its composition, is thus used well below its melting point of at least greater than 1400 °C.
Implementation Method 3
they can also take on the task of protecting the inner lining in the area of their arrangement from the abrasive influence of the iron carriers or sponge iron sliding past.
Data Source
Figure 1
AI summary
The invention relates to a direct reduction plant with at least one reactor which is equipped with a refractory material.