Rectangular Outlet Honeycomb Particulate Filter Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing particulate filters, such as plugged porous ceramic honeycomb filters, face challenges in achieving good pressure drop performance both clean and soot loaded, while also providing adequate ash storage and maintaining low manufacturing costs for the extrusion dies.
Innovation Solution
The development of a honeycomb structure with a large ratio of inlet to outlet cells and channels, where at least some outlet channels have a larger hydraulic diameter and a rectangular shape, along with a specific plugging pattern and extrusion die design that minimizes the use of expensive plunge EDM processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a large ratio of inlet to outlet cells and channels is used, then pressure drop performance is improved, but manufacturing complexity of extrusion dies increases
Solution Approach 1:
The extrusion die is divided into multiple pins (first pins and second pins) that are arranged in a matrix pattern. Each pin independently forms a cell channel, allowing the complex honeycomb structure to be created through repeated extrusion of simpler individual pin profiles. This segmentation enables the formation of numerous inlet and outlet cells without requiring an overly complex single-piece die design.
Solution Approach 2:
Different pins are designed with different cross-sectional areas: first pins have a first cross-sectional area and second pins have a second cross-sectional area. This local differentiation allows specific regions of the honeycomb structure to have different cell sizes, optimizing the ratio of inlet to outlet cells for improved pressure drop performance while keeping the overall die structure manageable.
2Reliability
If outlet channels have larger hydraulic diameter, then pressure drop performance is improved, but manufacturing precision requirements increase
Solution Approach 1:
The extrusion process allows for precise control of the hydraulic diameter of outlet channels by adjusting the cross-sectional area of the second pins. By changing this geometric parameter during manufacturing, the desired larger hydraulic diameter can be achieved without requiring post-manufacturing precision adjustments or complex machining operations.
3Reliability
If rectangular shape is used for outlet channels, then pressure drop performance is improved, but manufacturing cost increases
Solution Approach 1:
The extrusion die uses a matrix arrangement of pins that can be manufactured using standard forming processes. The rectangular outlet channels are created by the extrusion of the pin matrix structure, avoiding the need for expensive plunge EDM processes. The design copies the simple pin geometry into the final product, achieving complex channel shapes through a straightforward manufacturing process.
4Quantity of substance
If plugging pattern is optimized, then ash storage capacity is enhanced, but manufacturing complexity increases
Solution Approach 1:
The extrusion die is designed with plugs already positioned within the cell channels during the extrusion process. This preliminary placement of plugs allows the honeycomb structure to be formed with the plugging pattern already integrated, optimizing ash storage capacity without requiring complex post-extrusion plugging operations or sophisticated control systems.
Data Source
AI summary
A particulate filter having a honeycomb structure of a matrix of interconnected porous walls including inlet cells and outlet cells defining a plurality of inlet channels and outlet channels, respectively, wherein at least a portion of the outlet cells are larger than any of the inlet cells, and a cross-sectional shape of at least some of the outlet channels is rectangular. Honeycomb extrusion dies, honeycomb bodies, honeycomb structures, and methods of manufacture are described, as are other aspects.