Honeycomb Filter Element with Segmented Hexagonal Passages
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional diesel particulate filters (DPFs) face issues with increased pressure loss and reduced ash deposition capacity due to ash deposition patterns and catalyst distribution, which affects regeneration efficiency and fuel efficiency.
Innovation Solution
A filter element with a larger cross-sectional area and number of inflow passages compared to outflow passages, featuring regular hexagonal outflow passages and modified hexagonal inflow passages, arranged to optimize ash deposition and catalyst distribution, reducing pressure loss and regeneration temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the number of inlet cells is increased to increase ash deposition capacity, then the capacity for ash to be deposited increases, but the effective GSA decreases and pressure loss increases
Solution Approach 1:
The outlet cells are divided into two types: first hexagonal passages with larger cross-sectional area and second hexagonal passages with smaller cross-sectional area. This segmentation allows the inlet cells to be configured with different numbers (6 around first type, 8 around second type) to optimize the balance between ash deposition capacity and effective GSA, resolving the contradiction by creating heterogeneous cell structures rather than uniform ones
Solution Approach 2:
Different regions of the filter element have different cell configurations. The first hexagonal passages are surrounded by six inlet cells while second hexagonal passages are surrounded by eight inlet cells. This local quality variation allows certain regions to prioritize ash deposition capacity while other regions maintain higher effective GSA, thereby resolving the overall contradiction at the system level
2Quantity of substance
If the open area of inlet cells is increased to increase ash deposition capacity, then the capacity for ash to be deposited increases, but the pressure loss increases
Solution Approach 1:
The outlet cells are segmented into two types with different cross-sectional areas. The second hexagonal passages with smaller cross-sectional area are surrounded by eight inlet cells, providing increased ash deposition capacity in specific regions without requiring all inlet cells to have large open areas, thereby controlling overall pressure loss while maintaining ash deposition capacity
Solution Approach 2:
Instead of uniformly increasing the open area of all inlet cells (one-dimensional approach), the invention uses a two-dimensional arrangement where different inlet cell configurations (6 or 8 cells per outlet cell) are distributed across different regions. This dimensional approach allows ash deposition capacity to be increased in specific zones without proportionally increasing pressure loss across the entire filter
3Productivity
If inlet cells are deformed to increase effective GSA, then the effective GSA increases, but the total volume of inlet cells decreases and ash deposition capacity decreases
Solution Approach 1:
The outlet cells are segmented into two types: first hexagonal passages with larger cross-sectional area and second hexagonal passages with smaller cross-sectional area. This segmentation allows the system to maintain higher effective GSA in regions with first type outlets while providing adequate ash deposition capacity in regions with second type outlets, resolving the contradiction by distributing functions across different cell types
Solution Approach 2:
Different regions of the filter element have different cell configurations optimized for different functions. Regions with first hexagonal passages prioritize effective GSA and pressure characteristics, while regions with second hexagonal passages prioritize ash deposition capacity. This local quality differentiation resolves the contradiction by allowing each region to excel at its primary 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 solution effectively increases ash deposition capacity while maintaining effective surface area, lowering regeneration temperature and enhancing ignitability, thereby improving fuel efficiency and regeneration efficiency.
Implementation Method 1
the DPF is usually coated with an oxidation catalyst. When each cell is formed into an obtuse cross-sectional shape such as a hexagonal cross-sectional shape as in technologies disclosed in Patent Documents 2 and 3, an inner portion of the cell can evenly be coated with the catalyst.
Implementation Method 2
The DPF is a filter having a honeycomb structure constituted of a large number of mutually parallel fluid through channels partitioned by porous partition walls.
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
There is disclosed a filter element which can increase a capacity for ash to be deposited while suppressing decrease of an effective GSA and suppressing increase of a pressure loss and which additionally can lower a regeneration temperature by enhancing a regeneration limit and enhancing ignitability at regeneration. In a filter element which filters an exhaust gas from an internal combustion engine, including an inflow surface and an outflow surface; and a large number of inflow passages 16 and a large number of outflow passages 18A and 18B, the inflow passages 16 and the outflow passages 18A and 18B being partitioned by partition walls 20 made of a porous material, a total cross-sectional area of all the inflow passages 16 is larger than a total cross-sectional area of all the outflow passages 18A and 18B, and the number of the inflow passages 16 is larger than the number of the outflow passages 18A and 18B, a cross section of the filter element is formed by the large number of outflow passages 18A and 18B each having a regular hexagonal shape and the large number of inflow passages 16 each having a modified hexagonal shape, the large number of regular hexagonal outflow passages are formed by first hexagonal passages 18A, and second hexagonal passages 18B each having a cross-sectional area smaller than that of each of the first hexagonal passages 18A, an outer peripheral side of each of the first hexagonal passages 18A and the second hexagonal passages 18B is surrounded with six modified hexagonal inflow passages 16 via the partition walls 20, and the first hexagonal passages 18A and the second hexagonal passages 18B are regularly arranged.