Layered Ceramic Honeycomb Plugs for Exhaust Filtration
Solution Overview
Problem
Existing honeycomb structures for exhaust gas filtration face challenges in achieving sufficient mechanical strength while minimizing plug depth to reduce back pressure and enhance fuel economy, as shorter plugs can lead to insufficient mechanical strength and increased voids.
Innovation Solution
A method of forming layered plugs in ceramic honeycomb bodies, where a first layer is disposed on the channel walls and a second layer is positioned inward toward the axial center, using specific compositions and processes to enhance plug strength and depth without increasing voids, thereby achieving better mechanical strength and reduced back pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the plug depth is reduced to decrease back pressure and improve fuel economy, then the filter volume increases and regeneration frequency decreases, but the mechanical strength and push out strength of the plugs become insufficient
Solution Approach 1:
The plug is divided into two distinct layers: a first layer comprising porous ceramic material and a second layer comprising sealing material. This segmentation allows each layer to perform its specific function - the ceramic layer provides mechanical strength while the sealing layer ensures proper sealing - enabling shorter plug depths without sacrificing overall plug performance
Solution Approach 2:
Different regions of the plug are assigned different materials with specific properties tailored to local requirements. The first layer uses porous ceramic material for mechanical integrity and structural support, while the second layer uses sealing material for creating effective seals. This local differentiation allows the plug to achieve sufficient strength at reduced depths
2Manufacturing precision
If the amount of water in the plugging composition is reduced or particle size is increased to reduce voids in plugs, then plug quality improves, but plug depth becomes insufficient and mechanical strength decreases
Solution Approach 1:
The plug composition is segmented into two layers with different material properties. The first layer uses porous ceramic material optimized for mechanical strength, while the second layer uses sealing material optimized for void reduction and quality. This allows achieving high plug quality without compromising depth, as each layer contributes differently to overall plug performance
Solution Approach 2:
The plug is formed as a composite structure combining porous ceramic material and sealing material in distinct layers. This composite approach allows optimization of each material for its specific function - the ceramic provides structural integrity at reduced depths while the sealing material ensures low void content, thereby achieving both high quality and sufficient depth
3Productivity
If shorter plugs are used to provide less back pressure and higher filter volume, then fuel economy improves and manufacturing costs decrease, but plug mechanical strength becomes insufficient
Solution Approach 1:
The plug is segmented into a first layer of porous ceramic material providing mechanical strength and a second layer of sealing material providing structural integrity. This segmentation enables shorter overall plug depths that maintain sufficient push-out strength while increasing filter volume and reducing back pressure
Solution Approach 2:
The plug structure incorporates local quality differentiation where the ceramic material layer provides mechanical strength at the interface with channel walls, while the sealing material layer provides structural support. This localized optimization allows reduced plug depth without sacrificing mechanical strength
Data Source
AI summary
A porous ceramic honeycomb body (10) including intersecting walls that form channels (22) extending axially from a first end face to a second end face and layered plugs (62) comprised of a first layer (64) disposed on channel walls and a second layer (66) disposed inward toward an axial center of each respective channel on the first layer. The plugs seal at least one of a first portion of the channels at the first end face and a second portion of channels at the second end face of the porous ceramic honeycomb body.