Angularly Offset Catalyst Networks for Stable Flow
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Solution Overview
Problem
Existing catalyst networks in catalytic converters experience a decrease in porosity and increase in flow resistance over time, leading to unstable product yield and reduced service life due to compression under pressure, especially when arranged transversely to the fluid flow direction.
Innovation Solution
The catalyst networks are arranged with preferred directions that enclose an angle between 0° and 180°, incorporating a second noble metal wire embedded within a first precious metal wire network, creating a three-dimensional structure with angularly offset arrangements to enhance mechanical stability and prevent compression, and optionally using a helical second wire or an intermediate two-dimensional network to adjust catalyst properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If catalyst networks are arranged transversely to the fluid flow direction, then catalytic efficiency is improved, but flow resistance increases and porosity decreases over time
Solution Approach 1:
The patent applies asymmetry by arranging catalyst networks at specific non-perpendicular angles (e.g., 30°, 60°, or 120°) relative to the fluid flow direction rather than the conventional 90° transverse arrangement. This asymmetric angular configuration optimizes the balance between catalytic efficiency and flow resistance, preventing excessive compression and porosity loss while maintaining high catalytic performance.
Solution Approach 2:
The patent changes the geometric parameter of the catalyst network arrangement by specifying precise angular orientations (30°, 60°, 120°) relative to the flow direction. This parameter optimization allows the system to achieve both high catalytic efficiency and stable flow characteristics over time, resolving the contradiction between productivity and reliability.
2Ease of manufacture
If catalyst networks are arranged with parallel preferred directions, then manufacturing simplicity is improved, but mechanical stability decreases under pressure
Solution Approach 1:
The patent breaks the symmetry of parallel preferred directions by arranging catalyst networks at asymmetric angles (30°, 60°, or 120°) relative to the flow direction. This asymmetric configuration enhances mechanical stability under pressure by distributing stress more effectively across the network structure, while still maintaining relatively simple manufacturing procedures.
3Strength
If wire diameter is increased to improve tensile strength, then mechanical strength is improved, but catalyst surface area per mass decreases
Solution Approach 1:
The patent optimizes the wire diameter parameter to a specific range (50-120 μm) that balances mechanical strength and catalytic surface area. By precisely controlling this parameter within the optimal range, the system achieves both sufficient tensile strength for mechanical stability and adequate surface area per mass for high catalytic productivity.
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 arrangement maintains high mechanical stability and flow efficiency, reducing compression and maintaining a stable product yield over time, with optimal catalyst life and efficient catalysis achieved by the angularly offset and helical structure configurations.
Implementation Method 1
Catalysts in the sense of the invention are noble metal catalysts that are used in particular for gas reactions
Data Source
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AI summary
Known catalysts have several catalyst networks made of a precious metal wire arranged one behind the other, each containing a second precious metal wire that defines a preferred direction for the respective catalyst network. To provide a catalyst that ensures a product yield that is as reproducible as possible over time and that has a long lifetime, the invention proposes that the catalyst networks be arranged one behind the other such that the preferred directions of adjacent catalyst networks enclose an angle other than 0°.