Honeycomb Filter Catalyst Distribution for Purification and Pressure Loss
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Solution Overview
Problem
Honeycomb filters face challenges in achieving high purification efficiency and temperature rise performance without increasing pressure loss, particularly due to the blocking of pores by a large amount of catalyst, which affects exhaust gas flow.
Innovation Solution
The honeycomb filter is designed with a specific catalyst distribution where the amount of catalyst in the upstream partition portion is between 1.05 and 3.00 times that in the downstream partition portion, and the trapping layer is uniformly loaded with catalyst, ensuring efficient purification and temperature rise without excessive pressure loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a large amount of catalyst is loaded on the honeycomb filter to increase purification efficiency and temperature rise performance, then the purification efficiency and temperature rise performance are improved, but the pores of the partition portion and exhaust gas flow are blocked, increasing pressure loss
Solution Approach 1:
The patent applies local quality by creating different catalyst distribution patterns in different regions of the honeycomb filter. Specifically, the upstream region (inlet side) has a higher catalyst concentration than the downstream region (outlet side), with the catalyst amount ratio a/b ranging from 1.05 to 3.00. This non-uniform distribution optimizes purification efficiency where it is most needed while minimizing pressure loss, resolving the technical contradiction between purification performance and flow resistance.
2Temperature
If a large amount of catalyst is loaded on the honeycomb filter to increase temperature rise performance for promoting PM combustion, then the temperature rise performance is improved, but the pores of the partition portion are blocked, increasing pressure loss
Solution Approach 1:
The patent implements local quality by concentrating the catalyst in the upstream region where temperature rise is most critical for initiating PM combustion. The catalyst amount ratio a/b of 1.05 to 3.00 ensures sufficient heat generation at the inlet to promote combustion without excessively blocking pores. This localized catalyst placement achieves temperature rise performance while controlling pressure loss.
3Reliability
If the amount of catalyst in the upstream partition portion is increased to improve purification efficiency, then the purification efficiency is improved, but the exhaust gas flow is blocked, increasing pressure loss
Solution Approach 1:
The patent applies local quality by optimizing catalyst distribution with ratio a/b between 1.05 and 3.00, placing more catalyst in the upstream region where purification is most effective. This localized approach maximizes purification efficiency per unit of catalyst while minimizing impact on exhaust gas flow, resolving the contradiction between purification performance and productivity.
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
This configuration enhances purification efficiency and temperature rise performance while maintaining low pressure loss, allowing for effective regeneration of the filter by maintaining high temperatures during regeneration treatments.
Implementation Method 1
an oxidation catalyst for promoting the oxidation of HCs, CO, and the like in an exhaust gas may be loaded on the honeycomb filter to remove them by oxidation
Implementation Method 2
a catalyst may be loaded on the honeycomb filter to promote PM combustion
Implementation Method 3
a trapping layer for trapping and removing particulate matter (PM) contained in an exhaust gas
Implementation Method 4
a trapping layer for trapping and removing solid components contained in the fluid
Implementation Method 5
the temperature of the honeycomb filter can be increased by increasing the heat of the oxidation reaction to promote PM combustion
Data Source
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AI summary
A honeycomb filter 20 includes a plurality of porous partition portions 22 each forming a cell 23, the cell 23 being open at one end and closed at the other end and serving as a flow path of an exhaust gas, and a trapping layer 24 for trapping and removing solid components contained in the exhaust gas, the trapping layer 24 being formed on each of the partition portions 22. At least part of each of the partition portions 22 is loaded with a catalyst. The amount of catalyst a (g/L) in an upstream partition portion and the amount of catalyst b (g/L) in a downstream partition portion satisfy 1.05 ≤ a/b ≤ 3.00. A method for limiting a/b to this range may be a method for bringing the entire honeycomb structure including the partition portions 22 into contact with a catalyst component to form a catalyst and subsequently bringing only an upstream region of the honeycomb structure into contact with a catalyst component to form a catalyst.