Catalyzed Particulate Filter Coating for Low Pressure Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing particulate filters face a significant increase in pressure loss due to the reduction in pore diameters required for high PM capturing rates, which is not adequately addressed by existing technologies.
Innovation Solution
A catalyzed particulate filter with a porous support and a catalytic layer having a density of 2.0 g/cm³ or higher, combined with a catalyst material containing Ce-containing Zr-based or Ce-free Zr-based composite oxides or alumina-based composite oxides, and a capturing layer if necessary, to maintain a high particulate capturing rate while suppressing pressure loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pore diameters in the partitions are reduced to achieve high PM capturing rate, then the PM capturing rate is improved, but the pressure loss increases significantly
Solution Approach 1:
The patent applies porous materials with specific pore size distributions (bimodal or trimodal distribution) to create a multi-scale pore structure. This allows the filter to maintain high PM capturing efficiency through fine pores while providing larger pores to reduce flow resistance and pressure loss, effectively resolving the contradiction between capturing performance and energy loss.
Solution Approach 2:
The patent changes the pore diameter parameter by introducing a bimodal or trimodal pore size distribution instead of a uniform single-size pore structure. This parameter modification enables the system to achieve both high PM capture (via smaller pores) and low pressure loss (via larger pores), simultaneously satisfying both requirements that were previously contradictory.
2Reliability
If a catalyst coating layer is added to promote PM combustion and exhaust gas purification, then the catalytic performance is improved, but the pressure loss increases due to reduction in flow path
Solution Approach 1:
The catalyst coating layer is designed with a porous structure that provides high surface area for catalytic reactions while maintaining open pore channels for exhaust gas flow. The porous structure allows the catalyst to be highly effective without forming a dense layer that would block flow paths and increase pressure loss.
Solution Approach 2:
The patent uses composite material structures combining catalyst particles with porous support materials. This composite approach provides both the catalytic activity needed for PM combustion and exhaust gas purification and the porous structure needed to maintain low pressure loss, resolving the contradiction between catalytic performance and flow resistance.
3Reliability
If the catalyst coating layer density is increased to ensure sufficient catalyst amount, then the catalytic performance is improved, but the pressure loss increases
Solution Approach 1:
The catalyst coating layer employs a porous structure that achieves high catalyst dispersion and high surface area without requiring high density. The porous architecture allows sufficient catalyst contact with exhaust gas while maintaining open flow paths, decoupling the relationship between catalyst amount and pressure loss.
Solution Approach 2:
The patent changes the density parameter of the catalyst coating layer by introducing a controlled porous structure. This transforms the coating from a dense, high-pressure-loss structure to a porous structure that provides sufficient catalytic activity while maintaining low flow resistance, effectively resolving the contradiction.
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 maintains a high particulate capturing rate and suppresses the increase in pressure loss, achieving a PM capturing rate of 90% or higher and pressure loss of 7 kPa or less, while ensuring efficient exhaust gas purification.
Implementation Method 1
a catalytic layer provided on an exhaust gas passage wall of the support, the catalytic layer having a density of 2.0 g/cm³ or higher
Implementation Method 2
a support that is porous
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A catalyzed particulate filter 10 is a filter that is arranged in an exhaust passage 11 of an engine and captures particulate matter in exhaust gas, and includes a support 10A that is porous, and a catalytic layer 20 provided on a wall surface 16A of the support 10A, and the catalytic layer 20 has a density of 2.0 g/cm3 or higher.