Adsorber Double Envelope Corrosion Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing purification systems for wet gas streams containing CO2 and NOx face corrosion issues due to hot nitric acid formation during regeneration, leading to increased costs and risks with current corrosion-resistant material solutions.
Innovation Solution
A double gas plate configuration with a stainless steel inner envelope for corrosion protection and a carbon steel outer envelope for pressure resistance, along with a stainless steel plate for additional support, reduces corrosion risks and production costs by limiting plating to specific parts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the adsorber is made entirely of stainless steel (NAG type) to resist corrosion from hot nitric acid, then corrosion resistance is improved, but the manufacturing cost increases approximately threefold
Solution Approach 1:
The patent applies local quality by making only the ferrule (the specific component exposed to hot nitric acid during regeneration) of stainless steel, while the rest of the adsorber body can be made of less expensive materials. This targeted approach protects the critical corrosion-prone area without requiring expensive materials throughout the entire structure, thus resolving the contradiction between corrosion resistance and manufacturing cost.
Solution Approach 2:
The patent segments the adsorber into distinct components with different material requirements. The ferrule is separated as a specific component that requires corrosion-resistant material, while other parts can use standard materials. This segmentation allows selective application of expensive materials only where necessary, reducing overall cost while maintaining reliability in critical areas.
2Reliability
If a coating of noble material is applied on the inner surface of the ferrule to resist corrosion, then corrosion resistance is improved, but the additional cost largely offsets the benefit of using less expensive base material
Solution Approach 1:
The patent employs composite materials by combining stainless steel ferrule with less expensive adsorber body materials. This composite construction achieves the desired corrosion resistance in the critical ferrule area while using cost-effective materials for the bulk structure, avoiding the need for expensive coatings and achieving cost savings without compromising reliability.
3Ease of manufacture
If partial plating is applied only to the likely corroded part of the ferrule, then manufacturing cost is reduced, but the protection is not 100% safe against corrosion risks
Solution Approach 1:
The patent applies local quality by making the entire ferrule component of stainless steel rather than applying partial plating. This ensures complete and reliable corrosion protection of the ferrule (which is the only area exposed to hot nitric acid) while still using less expensive materials for the rest of the adsorber, achieving both cost efficiency and 100% protection reliability.
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 configuration effectively prevents corrosion while maintaining thermal insulation and pressure integrity, reducing overall costs and ensuring safe operation of the adsorber.
Implementation Method 1
The HNO3 are retained by the adsorbent of the adsorbers and NO and NO2 are partially retained.
Implementation Method 2
the double envelope solution is recommended because with the space between the shell and the outer envelope (of the internal part), this already constitutes very effective thermal insulation.
Data Source
Figure 1~2
Figure 3
AI summary
Equipment for purifying a gas stream comprising at least 0.02% by volume of water, CO2 and NOx, comprising an adsorber characterized by: a cavity (1); an adsorbent (2) comprised in the cavity (1); a carbon steel outer case (3); a stainless steel inner case (4) forming a space between 10 and 100 mm in width between said inner case and the outer case, wherein said space is at equal pressure with the cavity.