Non-linear Flow Channels in Catalytic Converters
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Solution Overview
Problem
Conventional catalytic converters with linear channel geometries are limited by diffusion rates, leading to reduced catalytic efficiency due to laminar exhaust flow, which restricts the reaction of toxic compounds like CO, NOX, and HC, necessitating increased channel length or substrate density at the cost of weight and manufacturing expense.
Innovation Solution
The introduction of non-linear channel geometries, such as helical and sinusoidal configurations, which generate vortical flows, enhancing diffusion and convection within catalytic converters, thereby increasing catalytic efficiency without the need for increased substrate volume or weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional linear channel geometries are used, then manufacturing is simpler and structure is easier, but catalytic efficiency is limited due to laminar flow and diffusion rates
Solution Approach 1:
The patent applies curved channel geometries (helical, sinusoidal, or meandering configurations) instead of straight linear channels. This curvature generates vortical flows and secondary movements that enhance mixing and mass transfer, thereby improving catalytic efficiency by 2-4 fold compared to conventional linear channels while maintaining the same substrate volume.
2Productivity
If channel length is increased to improve catalytic efficiency, then reaction effectiveness increases, but substrate volume and weight increase
Solution Approach 1:
By introducing curved pathways (helical, sinusoidal, or meandering) within the same substrate volume, the effective flow path length is increased without increasing the physical dimensions of the converter. This allows longer residence time and enhanced catalytic reactions within compact substrates, improving efficiency without increasing volume or weight.
Solution Approach 2:
The patent utilizes three-dimensional curved channel configurations that navigate through the substrate volume more efficiently. The helical and sinusoidal paths exploit the third dimension to create longer effective contact paths between exhaust gases and catalyst surfaces without increasing the external footprint or volume of the substrate.
3Productivity
If substrate density is increased to improve catalytic efficiency, then reaction effectiveness increases, but manufacturing cost and weight increase
Solution Approach 1:
The curved channel geometries enhance catalytic efficiency through improved flow dynamics (vortical flows, enhanced mixing, increased mass transfer) rather than through increased substrate density or catalyst loading. This allows achieving 2-4 fold efficiency improvement while maintaining the same substrate weight and material usage.
4Productivity
If linear parallel channels are used, then flow distribution is simpler, but diffusion-limited reactions reduce catalytic performance
Solution Approach 1:
The patent introduces curved channel configurations (helical, sinusoidal, or meandering) that generate vortical flows and secondary movements. These complex flow patterns enhance mixing and mass transfer to the catalyst surfaces, overcoming the diffusion limitations of laminar flow in straight channels and improving catalytic efficiency by 2-4 fold.
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 non-linear channel geometries enhance catalytic efficiency by 2-4 fold compared to linear channels, reduce substrate volume and cost, and improve energy efficiency through reduced backpressure and faster light-off times, while maintaining effective pollution control.
Implementation Method 1
non-linear channel geometries, such as helical and sinusoidal configurations, which generate vortical flows, enhancing diffusion and convection within catalytic converters
Implementation Method 2
enhancing diffusion and convection within catalytic converters
Implementation Method 3
enhancing diffusion and convection within catalytic converters
Data Source
AI summary
Disclosed is a honeycomb catalyst substrate core having geometrically non-linear flow channels. In an embodiment, the honeycomb catalyst substrate core includes helical flow channels. In another embodiment, the honeycomb catalyst substrate core includes sinusoidal flow channels. In yet another embodiment, the honeycomb catalyst substrate core includes helical plus sinusoidal flow channels. The honeycomb catalyst substrate core comprises a plurality of parallel non-linear flow channels formed along a longitudinal axis of symmetry of the catalyst substrate core, each non-linear flow channel configured such that eddies occurs during engine exhaust gas flow. Also disclosed is a method for manufacturing a ceramic honeycomb having non-linear flow channels, comprising the steps extrusion soft ceramic material through a die whilst the die moves through six degrees of freedom along its axis of symmetry. Disclosure includes a method for manufacturing a ceramic honeycomb having non-linear flow channels using three-dimensional printing.