Additively Manufactured Catalytic Converter Substrates with Gradient Cell Density
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional catalytic converters have limited design geometry due to extrusion forming processes, resulting in restricted surface area for gas reaction and uneven precious metal consumption along the converter's length.
Innovation Solution
A catalytic converter with additively manufactured three-dimensional structures featuring varying cross-sectional zones with densely arranged cells and microstructures, optimized for exhaust gas flow, providing a tailored active surface area that increases upstream and decreases downstream, utilizing biomimetic designs and materials like ceramic and metal nanoparticles for efficient gas exchange.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If extrusion forming processes are used to create catalytic converter structures, then the manufacturing process is simple and reliable, but the design geometry is limited and surface area for gas reaction is restricted
Solution Approach 1:
The patent transitions from traditional two-dimensional extrusion-formed honeycomb structures to three-dimensional additively manufactured structures with complex spatial geometries. This dimensional expansion enables creation of intricate cellular pathways and surface configurations that maximize gas reaction surface area while maintaining manufacturing feasibility through additive processes.
Solution Approach 2:
The patent employs parameter changes by varying cell density, cell size, and structural geometry along the length of the catalytic converter. Upstream zones feature higher cell density and smaller cell sizes to handle high-velocity exhaust gases, while downstream zones have lower density and larger cells. This gradient approach optimizes surface area for gas reaction across different flow conditions.
2Ease of manufacture
If uniform cell density is used throughout the catalytic converter, then the structure is simple to manufacture, but precious metal consumption is uneven with faster depletion near the inlet
Solution Approach 1:
The patent applies local quality by creating zones with different cell densities and structural properties at different locations along the converter length. Upstream zones have higher cell density to provide more surface area where precious metals are most needed due to higher reaction rates and gas flow velocities. Downstream zones have lower density, reducing precious metal consumption in regions where exhaust gases have already undergone significant conversion.
Solution Approach 2:
The patent introduces dynamic variation in structural parameters along the flow path, transitioning from high-density cellular structures at the inlet to low-density structures at the outlet. This dynamic gradient design adapts the catalyst substrate geometry to match the changing exhaust gas composition, temperature, and flow velocity profiles, optimizing precious metal utilization throughout the converter length.
3Area of stationary object
If additively manufactured three-dimensional structures with varying cell density are used, then surface area for gas reaction is optimized and precious metal usage is improved, but the manufacturing complexity increases
Solution Approach 1:
The patent utilizes three-dimensional additive manufacturing to create complex spatial structures with varying cell densities that cannot be achieved through traditional extrusion processes. This enables optimization of active surface area by arranging cells in intricate three-dimensional patterns and gradients, maximizing gas-catalyst contact while managing manufacturing complexity through digital design and additive fabrication capabilities.
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 enhances gas exchange efficiency, optimizes precious metal usage, and reduces package size by creating tailored meso- and microstructures that vary along the converter's length, ensuring more active surface area for reaction and efficient precious metal distribution.
Implementation Method 1
a wash-coat layer deposited on surfaces of the cells forming active surface area configured to react with exhaust gas traveling along the length
Data Source
AI summary
A catalytic converter includes a catalyst substrate including a body having a length and defining a plurality of zones along the length, with each zone having at least one cross-sectional structure defining a plurality of cells forming an exhaust gas flow path through the length via cells of adjacent zones, and the cells being more densely arranged within the at least one cross-sectional structure of an upstream zone than an adjacent downstream zone. The catalytic converter also includes a wash-coat layer deposited on surfaces of the cells forming active surface area configured to react with exhaust gas traveling along the length. The exhaust gas flows along the exhaust gas flow path through the cells such that more active surface area is available for reaction in each upstream zone than an adjacent downstream zone.