Plugged Honeycomb Structure with Optimized Corner Cells

Solution Overview

Problem

Conventional plugged honeycomb structures experience increased pressure loss due to the deposition of incombustible particulate matter, particularly when the shapes of outermost circumferential cells are not optimally designed, leading to potential cracks and reduced isostatic strength.

Innovation Solution

A plugged honeycomb structure with prismatic columnar segments, a bonding layer, and plugging portions arranged in specific patterns to create varying cell shapes, where corner rim circumferential wall cells have larger open areas compared to non-corner rim cells, inhibiting pressure loss while maintaining isostatic strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the shapes of outermost circumferential cells are not optimally designed, then the structure is simpler to manufacture, but pressure loss increases due to deposition of incombustible particulate matter

Engineering Contradiction:

Improveease of manufactureVSAvoidpressure loss

Core Design Contradiction:

Ease of manufactureVSLoss of energy

Solution Approach 1:

The patent applies local quality by creating different cell shapes at different locations within the honeycomb structure. Specifically, corner rim circumferential wall cells are designed with larger open areas compared to non-corner rim circumferential wall cells. This localized variation in cell geometry optimizes the balance between manufacturing simplicity and pressure loss reduction by addressing the specific flow characteristics needed at corner versus non-corner positions.

Inventive Principle:

Principle #3Local quality

2Ease of manufacture

If the shapes of outermost circumferential cells are not optimally designed, then the manufacturing process is simpler, but cracks occur and isostatic strength is reduced

Engineering Contradiction:

Improveease of manufactureVSAvoidisostatic strength

Core Design Contradiction:

Ease of manufactureVSStrength

Solution Approach 1:

The patent applies local quality by creating different cell shapes at different locations within the honeycomb structure. Specifically, corner rim circumferential wall cells are designed with larger open areas compared to non-corner rim circumferential wall cells. This localized variation in cell geometry optimizes the balance between manufacturing simplicity and pressure loss reduction by addressing the specific flow characteristics needed at corner versus non-corner positions.

Inventive Principle:

Principle #3Local quality

3Loss of energy

If corner rim circumferential wall cells have larger open areas, then pressure loss is reduced, but the structural complexity increases

Engineering Contradiction:

Improvepressure lossVSAvoidstructural complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The patent applies local quality by creating different cell shapes at different locations within the honeycomb structure. Specifically, corner rim circumferential wall cells are designed with larger open areas compared to non-corner rim circumferential wall cells. This localized variation in cell geometry optimizes the balance between manufacturing simplicity and pressure loss reduction by addressing the specific flow characteristics needed at corner versus non-corner positions.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent applies asymmetry by intentionally creating non-uniform cell shapes throughout the honeycomb structure. Corner cells have different open areas compared to non-corner cells, breaking the symmetric pattern. This asymmetric design is deliberately introduced to optimize pressure loss characteristics while maintaining manufacturing feasibility, as the asymmetry is applied in a controlled, repeating pattern rather than being entirely irregular.

Inventive Principle:

Principle #4Asymmetry

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 structure effectively reduces pressure loss during particulate matter deposition while maintaining sufficient isostatic strength, preventing cracks and ensuring efficient filtration of exhaust gases.

Implementation Method 1

a bonding layer bonding side surfaces of the plurality of honeycomb segments to one another

Methodology Applied

Scientific EffectAdhesion: Adhesive

Implementation Method 2

When an exhaust gas containing the particulate matter flows into the plugged honeycomb structure from an inflow end face (a first end face) of the plugged honeycomb structure and when the exhaust gas passes through the partition walls, the particulate matter in the exhaust gas is filtered

Methodology Applied

Scientific EffectPhysical filtration: Filter (physical)

Data Source

PatentUS10857499B2Plugged honeycomb structure

Publication Date: 2020.12.08 NGK INSULATORS LTD

AI summary

The plugged honeycomb structure includes a plurality of honeycomb segments, a bonding layer, and plugging portions which plug open ends of cells of each honeycomb segment, and in the honeycomb segment, at least two types of cells having different sectional shapes are formed to constitute predetermined repeated arrangement patterns, and in rim circumferential wall cells including rims of the cells surrounded with partition walls and segment circumferential walls, an inflow open area of each corner rim circumferential wall cell disposed in each corner portion of the honeycomb segment is 1.1 times or more as large as an average inflow open area of non-corner rim circumferential wall cells arranged in portions other than the corner portions, or an outflow open area of the corner rim circumferential wall cell is 1.1 times or more as large as an average outflow open area of the non-corner rim circumferential wall cells.