Honeycomb Filter Uniform Coating via Pneumatic Aerosol

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Solution Overview

Problem

Honeycomb filters used in diesel particulate filters experience rapid pressure loss due to particulate matter accumulation, and existing production methods lack efficiency in forming a uniform collection layer on the filter's surface.

Innovation Solution

A honeycomb filter production apparatus that secures a base with a porous ceramic structure, uses pressurized gas to disperse powder as an aerosol, and controls airflow to uniformly coat the powder on the inner surface of the filter cells, ensuring a uniform collection layer formation through a combination of powder transfer, suction, and heat treatment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a collection layer is formed on the surface of a honeycomb filter base to reduce pressure loss, then filtration efficiency is improved, but manufacturing complexity increases due to the need for precise powder coating control

Engineering Contradiction:
Improvefiltration efficiencyVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs a pneumatic powder coating system where pressurized gas flows through the honeycomb base to carry powder particles uniformly onto the internal surfaces. This pneumatic approach replaces complex mechanical coating mechanisms with a fluid-based delivery system, achieving uniform collection layer formation while maintaining relatively simple device architecture.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The patent controls the collection layer thickness and uniformity by adjusting parameters such as gas flow rate, powder concentration, and coating duration. By varying these parameters, the system can produce consistent collection layers with desired properties without requiring complex mechanical adjustment mechanisms, thus reducing manufacturing complexity while ensuring filtration efficiency.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If powder is transferred using pressurized gas to form a uniform collection layer, then coating uniformity is improved, but energy consumption increases

Engineering Contradiction:
Improvecoating uniformityVSAvoidenergy consumption
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The pressurized gas system serves multiple functions: it transports powder particles, provides the carrier medium for uniform distribution, and acts as the coating delivery mechanism. This multi-functionality eliminates the need for separate systems for each task, reducing overall energy consumption while maintaining coating uniformity through the integrated approach.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The honeycomb base structure with its porous walls allows gas to flow through and distribute powder uniformly across internal surfaces. The porous architecture naturally promotes even coating distribution without requiring high gas velocities or excessive energy input, as the gas follows the existing flow paths through the honeycomb cells.

Inventive Principle:
Principle #31Porous materials

3Manufacturing precision

If additional cleaning steps are added to remove surplus powder, then product quality is improved, but productivity decreases

Engineering Contradiction:
Improveproduct qualityVSAvoidproductivity
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The system is designed so that excess powder naturally falls away from the honeycomb base due to gravity after the coating process. The base is tilted or positioned to allow surplus powder to self-remove without requiring active cleaning mechanisms. This self-cleaning capability maintains product quality by eliminating the need for additional cleaning steps, thereby preserving productivity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent applies a slightly excessive amount of powder during coating to ensure complete coverage of all internal surfaces. The knowledge that some excess will naturally fall away allows the system to use a simpler, faster coating process without requiring precise dosage control or subsequent cleaning operations, thus maintaining both quality and productivity.

Inventive Principle:
Principle #16Partial or excessive action

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 apparatus produces honeycomb filters with a uniform collection layer, reducing pressure loss and enhancing filtration efficiency while maintaining high productivity and yield, without the need for additional drying or cleaning steps.

Implementation Method 1

transfers a powder together with an air current by utilizing pressurized gas; the powder transferred from the powder transfer section together with the air current being mixed with another gas in the introduction section

Methodology Applied
Scientific EffectAerosol: Aerosol

Implementation Method 2

transfers a powder together with an air current by utilizing pressurized gas; the powder transferred from the powder transfer section together with the air current being mixed with another gas

Methodology Applied
Scientific EffectGas dispersion: Dispersion (of waves)

Implementation Method 3

sucks the gas that has passed through the base secured by the workpiece securing section by reducing pressure on the other side of the workpiece securing section as compared with the one side of the workpiece securing section

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 4

a suction section that is disposed on the other side of the workpiece securing section, and sucks the gas that has passed through the base

Methodology Applied
Scientific EffectSuction: Suction

Implementation Method 5

a base formed of a porous body; a collection layer that is formed on the surface of the base and collects particles; the exhaust gas passes through the partition wall

Methodology Applied
Scientific EffectPorosity: Porosity

Data Source

PatentEP2371452B1Honeycomb filter production apparatus
Publication Date: 2016.03.16 NGK INSULATORS LTD
  • EP2371452B1 patent drawingFigure 1
  • EP2371452B1 patent drawingFigure 2
  • EP2371452B1 patent drawingFigure 3

AI summary

A honeycomb filter production apparatus includes: a workpiece securing section (10) for securing a base of a honeycomb filter (11); a powder transfer section (20) that is disposed on one side of the workpiece securing section (10), and transfers a powder together with an air current by utilizing pressurized gas; an introduction section (40) that is provided between the powder transfer section (20) and the workpiece securing section (10), the powder transferred from the powder transfer section (20) together with the air current being mixed with another gas in the introduction section (40), and introduced into the base secured by the workpiece securing section (10) when the apparatus is used; a suction section (30) that is disposed on the other side of the workpiece securing section (10), and sucks the gas that has passed through the base secured by the workpiece securing section (10) by reducing pressure on the other side of the workpiece securing section (10) as compared with the one side of the workpiece securing section (10) using suction means; a cleaning section (50) for removing a surplus powder adhering to an end face of the base after the introduction of the powder; a judgment section (60) for judging an amount of the powder adhering to the base; and a workpiece transfer section (70) for transferring the base among the workpiece securing section (10), the cleaning section (50), and the judgment section (60).