Honeycomb Structure Circumferential Wall Porosity Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Honeycomb structures with high porosity face issues with catalyst slurry exudation and insufficient strength, leading to poor workability and increased risk of breakage during catalyst loading and use.
Innovation Solution
A honeycomb structure with a porous circumferential wall and a coat layer that penetrates into the pores of the circumferential wall, improving the strength and preventing catalyst slurry exudation by occluding pores and reinforcing the wall.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the porosity of the circumferential wall is increased to 35% or more, then the pressure loss is reduced and exhaust gas flow is improved, but the catalyst slurry passes through the pores and exudes on the outer surface, deteriorating workability
Solution Approach 1:
The patent applies local quality by creating a dual-porosity structure where the circumferential wall and partition wall have different porosity values. The circumferential wall has lower porosity (20-30%) to prevent slurry exudation, while the partition wall maintains higher porosity (50-75%) for effective catalyst function and low pressure loss.
Solution Approach 2:
The patent segments the honeycomb structure into two functional zones: the circumferential wall with controlled low porosity for structural integrity and slurry containment, and the partition wall with high porosity for catalyst performance. This segmentation allows each zone to optimize its properties independently.
2Loss of energy
If the porosity of the circumferential wall is increased to 35% or more, then the exhaust gas flow is improved, but the circumferential wall lacks sufficient strength and is easily broken during chucking
Solution Approach 1:
The patent applies local quality by assigning different porosity values to different parts of the structure. The circumferential wall uses lower porosity (20-30%) to provide sufficient mechanical strength for handling and mounting, while the partition wall uses higher porosity (50-75%) to minimize flow resistance.
3Loss of energy
If the porosity of the entire honeycomb structure is increased, then the pressure loss is reduced, but the isostatic strength decreases and the structure is easily broken during transportation and use
Solution Approach 1:
The patent applies local quality by differentiating porosity between structural components (circumferential wall with 20-30% porosity for strength) and functional components (partition wall with 50-75% porosity for low pressure loss). This localized differentiation resolves the contradiction between overall strength and pressure loss reduction.
4Quantity of substance
If the porosity of the partition wall is increased to 50% or more, then the catalyst loading capacity is improved, but the catalyst slurry exudes through the circumferential wall pores
Solution Approach 1:
The patent applies local quality by creating distinct porosity zones: the partition wall has high porosity (50-75%) to maximize catalyst loading capacity and surface area, while the circumferential wall has low porosity (20-30%) to contain the slurry during the loading process and prevent exudation.
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 effectively prevents catalyst slurry exudation and enhances the structural strength of the honeycomb, improving workability and reducing breakage risks during catalyst loading and use.
Implementation Method 1
a coat layer that is disposed on at least a part of the outer surface of the circumferential wall, wherein a part of the coat layer penetrates into the pores of the circumferential wall
Implementation Method 2
a honeycomb substrate having a porous partition wall that defines a plurality of cells that extend from an inlet end face as an inlet side for a fluid to an outlet end face as an outlet side for the fluid
Data Source
AI summary
A honeycomb structure includes a honeycomb substrate having a porous partition wall that defines a plurality of cells that extend from an inlet end face as an inlet side for a fluid to an outlet end face as an outlet side for the fluid, and a porous circumferential wall that is monolithically formed with the partition wall, and a coat layer that is disposed on at least a part of the outer surface of the circumferential wall. Here, a part of the coat layer penetrates into the pores of the circumferential wall, and a thickness of the part of the coat layer that penetrates into the pores of the circumferential wall is from 1 to 90% of the thickness of the circumferential wall.