Honeycomb Filter Zoned Catalyst Layer for Thermal Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional honeycomb filters have a low regeneration limit value, leading to frequent regeneration processes that decrease fuel economy and increase the risk of cracks due to uneven PM capture and temperature differences across the filter.
Innovation Solution
A honeycomb filter design with a catalyst supporting layer covering 25% to 90% of the gas inlet side and no catalyst supporting layer in 10% of the gas outlet side, featuring higher thermal conductivity in the non-catalyst areas and controlled pore diameters to ensure uniform PM capture and reduce thermal impacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If catalyst supporting layer is formed uniformly across the entire honeycomb filter, then PM capture efficiency is improved, but temperature difference between gas inlet side and gas outlet side increases causing low regeneration limit value
Solution Approach 1:
The patent applies local quality by forming the catalyst supporting layer only in a specific region (20-80% from gas inlet side) rather than uniformly across the entire filter. This creates different functional zones: the catalyst region for PM capture and the non-catalyst region (especially at gas outlet side) for heat dissipation, thereby reducing temperature difference and increasing regeneration limit value
Solution Approach 2:
The patent segments the honeycomb filter into distinct functional regions: a catalyst supporting layer region covering 20-80% of the length from the gas inlet side, and a non-catalyst region covering the remaining areas including 10% from the gas outlet side. This segmentation allows independent optimization of PM capture efficiency and thermal management
2Reliability
If catalyst supporting layer covers entire filter surface, then PM capturing efficiency increases, but pressure loss increases
Solution Approach 1:
The catalyst supporting layer is localized to the region where PM capture is most effective (20-80% from gas inlet side), while the gas outlet side region (10% from outlet) remains without catalyst supporting layer. This reduces overall catalyst amount and corresponding pressure loss while maintaining sufficient PM capture efficiency
3Reliability
If high amount of catalyst is supported on gas outlet side, then PM capture is improved, but thermal impact and crack risk increase due to high temperature
Solution Approach 1:
The patent extracts the catalyst supporting layer from the gas outlet side region (10% from outlet), removing the source of excessive heat generation in that area. This prevents thermal impact and crack risk while maintaining PM capture capability in the catalyst region
Solution Approach 2:
The non-catalyst region is specifically created at the gas outlet side (10% from outlet) to serve as a thermal management zone with higher thermal conductivity, protecting the filter structure from thermal damage while the catalyst region maintains PM capture function
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 design achieves a higher regeneration limit value by minimizing temperature differences and PM capture disparities across the filter, reducing pressure loss and maintaining high PM capturing efficiency while preventing cracks during regeneration.
Implementation Method 1
heat radiation in the end face neighborhood on the gas outlet side surely progress. In this case, the temperature rise on the gas outlet side is suppressed, and therefore a thermal impact caused by the temperature difference between the gas inlet side and the gas outlet side of the honeycomb filter tends not to be generated
Implementation Method 2
a catalyst supporting layer is formed in an area on which the catalyst is to be supported, so that the catalyst is supported on the catalyst supporting layer
Implementation Method 3
a catalyst used for purifying and/or converting exhaust gases may be supported thereon
Data Source
Figure 1
Figure 2(a)~2(b)
Figure 3
AI summary
An object of the present invention is to provide a honeycomb filter having a high regeneration value, the honeycomb filter comprising a pillar-shaped honeycomb fired body having a large number of cells each sealed at either end thereof and placed longitudinally in parallel with one another with a cell wall therebetween, and allowing gases to flow into one of the end face sides and to flow out from the other end face side, wherein no catalyst supporting layer is formed in an area covering 10% of the overall length of the honeycomb filter from the gas outlet side; a catalyst supporting layer is formed in an area covering 25 to 90% of the overall length of the honeycomb filter in an area of 90% of the overall length from the gas inlet side; and a thermal conductivity of the area in which no catalyst supporting layer is formed is higher than a thermal conductivity of the area in which the catalyst supporting layer is formed in the honeycomb filter; and modes a (µm) and b (µm) satisfy the following inequalities (1) and (2) : (a - b) ≤ 5 ... (1), and 10 ≤ a ≤ 20 ... (2), the mode a being a mode of pore diameters obtained by measuring pore distribution of the area in which no catalyst supporting layer is formed and the mode b being a mode of pore diameters obtained by measuring pore distribution of the area in which the catalyst supporting layer is formed in the honeycomb filter.