Honeycomb Filter End Aggregate Layer Crack Suppression
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Solution Overview
Problem
Honeycomb filters used in diesel particulate filters (DPFs) face issues with crack generation in plugged portions due to heat during regeneration, which affects their durability and performance.
Innovation Solution
A honeycomb filter design featuring end aggregate layers made of particulate aggregate material with a thickness of 0.5 to 5 mm on the surfaces of first plugged portions, along with porous collecting layers on the inflow-cell-side surfaces, to reduce direct contact between deposited PM and plugged portions, thereby minimizing heat conduction and crack formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If collecting layers are formed on the surfaces of partition walls on the side of inflow cells to increase PM deposition capacity, then the number of regeneration treatment times can be decreased, but the amount of heat generated during regeneration increases, causing cracks in plugged portions
Solution Approach 1:
An end aggregate layer is introduced as an intermediary between the collected PM and the plugged portion. This layer acts as a heat insulator that prevents direct heat conduction from the PM to the plugged portion during regeneration, thereby preventing cracks while maintaining PM collection capacity
Solution Approach 2:
The filter structure uses composite material configuration with different layers serving different functions: the collecting layer (porous material with smaller particle diameter) for PM separation and the end aggregate layer (particulate aggregate material) for thermal insulation, creating a multi-functional composite structure
2Reliability
If the thickness of end aggregate layers is increased to improve heat insulation, then crack generation is suppressed, but the pressure drop increases
Solution Approach 1:
The thickness of the end aggregate layer is optimized within a specific range (0.5 to 5 mm) to achieve the right balance between heat insulation performance and pressure drop. This parameter optimization ensures sufficient thermal protection while maintaining acceptable flow characteristics
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 proposed design effectively suppresses crack generation in plugged portions during regeneration, maintaining filter integrity and performance even with increased PM deposition, while also reducing pressure drop and improving PM collection efficiency.
Implementation Method 1
minimizing heat conduction and crack formation
Implementation Method 2
a porous collecting layer formed on the surfaces of the partition walls on the side of the inflow cells
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
There is disclosed a honeycomb filter which can suppress generation of cracks in plugged portions due to heat generated by burning of a PM during regeneration. The honeycomb filter comprises a honeycomb basal body 2 including porous partition walls 6 arranged to form a plurality of cells disposed in parallel with one another and including inflow cells 4a into which a fluid can flow and outflow cells which are formed adjacent to the inflow cells 4a and out of which the fluid can flow; first plugged portions with which one end 5b of each of the inflow cells 4a is plugged; second plugged portions 3b with which the other end 5a of each of the outflow cells is plugged; porous collecting layers formed on the surfaces of the partition walls 6 on the side of the inflow cells 4a; and end aggregate layers made of a particulate aggregate material and formed on the surfaces of the first plugged portions on the side of the inflow cells, and a thickness of the end aggregate layers is from 0.5 to 5 mm.