Containment Wall Slits for Ammonia Synthesis Reactors

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing systems of walls for catalytic beds in reactors face challenges such as complexity in construction, high costs due to the need for expensive materials resistant to nitriding, and mechanical strength issues under operational stresses, particularly in ammonia synthesis reactors.

Innovation Solution

A system of walls with a containment wall of suitable thickness and material, featuring slits for gas permeability and impermeable portions for mechanical support, eliminating the need for multiple welds and allowing for the use of conventional materials like stainless steel, which reduces production costs and maintains mechanical strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If systems of walls with tubular modules and grids are used for gas distribution in catalytic beds, then gas distribution and catalyst support functions are achieved, but construction complexity increases due to multiple welds required to assemble rods and modules

Engineering Contradiction:
Improveease of constructionVSAvoidconstruction complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent combines multiple separate components (tubular modules, grids, and support structures) into a single integrated containment wall structure. The containment wall is formed as one piece with built-in gas distribution channels and support surfaces, eliminating the need for assembling multiple welded components and significantly simplifying construction.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The containment wall serves multiple functions simultaneously: it contains the catalyst, distributes gas through integrated channels, provides mechanical support, and resists nitriding. This multi-functional design replaces the need for separate specialized components, reducing construction complexity while maintaining all necessary functions.

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

2Reliability

If expensive nitriding-resistant materials like Inconel are used for thin-walled components, then mechanical strength and resistance to nitriding effects are improved, but material costs increase significantly

Engineering Contradiction:
Improveresistance to nitridingVSAvoidmaterial cost
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent applies different material properties to different regions of the containment wall. The thin-walled portions that are exposed to synthesis gas and subject to nitriding are made from nitriding-resistant materials, while thicker structural portions can use conventional, less expensive materials. This localized material selection optimizes both performance and cost.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The containment wall is constructed using composite material structures, combining nitriding-resistant materials in critical thin-walled areas with conventional materials in non-critical areas. This composite approach achieves the necessary resistance to nitriding effects while significantly reducing overall material costs compared to using expensive materials throughout.

Inventive Principle:
Principle #40Composite materials

3Quantity of substance

If conventional materials like stainless steel are used for containment walls, then material costs are reduced, but mechanical strength under operational thrusts and nitriding effects deteriorates

Engineering Contradiction:
Improvematerial costVSAvoidmechanical strength
Core Design Contradiction:
Quantity of substanceVSStrength

Solution Approach 1:

The containment wall is divided into functional segments with different thicknesses and material properties. Thin-walled portions with slit openings use nitriding-resistant materials to maintain strength under nitriding, while thicker structural portions use conventional materials for cost efficiency. This segmentation allows optimal material selection for each functional requirement.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes material parameters (composition, thickness) based on local operational conditions. By adjusting wall thickness and material composition to match the specific demands of each region (exposed to gas vs. structural support), the design achieves adequate mechanical strength with conventional materials in non-critical areas while using enhanced materials only where necessary.

Inventive Principle:
Principle #35Parameter changes

4Productivity

If thin-walled structures with slit openings are used for gas distribution, then gas permeability and optimal load loss are achieved, but mechanical strength and resistance to deformation under thrusts deteriorate

Engineering Contradiction:
Improvegas distribution efficiencyVSAvoidmechanical strength
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The containment wall features local variations in thickness and material properties. Regions with slit openings for gas distribution have optimized thin walls with appropriate material composition to ensure gas permeability and controlled load loss, while adjacent structural regions have increased thickness and strength to withstand mechanical thrusts and maintain overall structural integrity.

Inventive Principle:
Principle #3Local quality

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

The solution simplifies construction, reduces material costs, and maintains mechanical strength and resistance to nitriding effects, enabling optimal gas distribution and catalyst support without the need for expensive materials.

Implementation Method 1

dotted with a plurality of slits arranged in a predetermined order and number, of a size such as to allow the free passage through them of the synthesis gases

Methodology Applied
Scientific EffectGas permeability through slits: Porosity

Implementation Method 2

Preferably, the containment wall also constitutes a mechanical support for said catalytic bed through said portions impermeable to gases

Methodology Applied
Scientific EffectMechanical support and containment: Physical Containment

Implementation Method 3

the inner components of the reactor and in particular the walls of the gas distribution system in the catalytic beds, are subjected to surface nitriding effects in normal operating conditions of the reactor that result in a progressive reduction of the mechanical strength of said components

Methodology Applied
Scientific EffectNitriding resistance: Nitriding

Data Source

PatentEP1993718B1Wall system for catalytic beds of synthesis reactors
Publication Date: 2019.07.03 CASALE SA
  • EP1993718B1 patent drawingFigure 1
  • EP1993718B1 patent drawingFigure 2
  • EP1993718B1 patent drawingFigure 3

AI summary

Described here is a system (8; 9; 50) of walls for catalytic beds of reactors (1) for the heterogeneous synthesis of chemical compounds characterised in that it comprises a wall (14) of predetermined thickness in direct contact with a catalytic bed (7) for containing it, said wall having a plurality of portions (17) permeable to gases and a plurality of portions (19; 54; 55) impermeable to gases, said portions (17) permeable to gases each being equipped with a plurality of slits (18; 52, 53; 60; 70) of a size such as to allow the free passage of the synthesis gases through them but not the passage of the catalyst.