Regenerable air filter

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Solution Overview

Problem

Air filters used in clean room and HVAC applications face challenges in efficiently removing molecular contamination, particularly low molecular size volatile organic compounds, leading to short service lifecycles and high costs, with traditional regenerable filters being unsustainable due to high filtration efficiency requirements.

Innovation Solution

A heat-resistant regenerable air filter assembly utilizing a carbon fiber felt material as a sealing medium between the adsorbent panel and frame, which provides a higher pressure drop than the adsorbent panel, allowing for effective regeneration and extended service life, while maintaining filtration efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional potting or adhesive compounds are used to seal the filter panel to the frame, then a reliable seal is provided, but the filter cannot be regenerated due to degradation at high temperatures

Engineering Contradiction:
Improvesealing reliabilityVSAvoidregenerability
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The sealing material changes from traditional polyurethane adhesive to carbon fiber felt, fundamentally altering the material parameters to withstand high temperatures. This parameter change enables the seal to survive regeneration cycles at temperatures above 200°C while maintaining sealing effectiveness.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The solution uses a composite sealing structure combining carbon fiber felt with a heat-resistant adhesive or sealant. This composite material provides both the mechanical sealing properties needed for reliability and the thermal stability required for regenerability.

Inventive Principle:
Principle #40Composite materials

2Reliability

If the filter is designed for high filtration efficiency to meet clean room requirements, then AMC removal is improved, but the service lifecycle becomes short and cost increases

Engineering Contradiction:
Improvefiltration efficiencyVSAvoidservice lifecycle
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The filter is designed to be regenerated by discarding the accumulated molecular contamination through thermal desorption. The adsorbent material is heated to temperatures above 200°C to release trapped contaminants, then cooled and reused, extending service life from months to years.

Inventive Principle:
Principle #34Discarding and recovering

Solution Approach 2:

The filter operates in periodic cycles of service and regeneration. During service, it adsorbs molecular contamination; during regeneration, it is heated to desorb contaminants. This periodic action allows repeated use while maintaining high filtration efficiency.

Inventive Principle:
Principle #19Periodic action

3Ease of repair

If the sealing material is made heat resistant to enable regeneration, then regenerability is improved, but the pressure drop increases significantly

Engineering Contradiction:
ImproveregenerabilityVSAvoidpressure drop
Core Design Contradiction:
Ease of repairVSStress or pressure

Solution Approach 1:

The carbon fiber felt seal is designed with specific local properties: it is placed only at the peripheral sealing zone rather than across the entire filter surface. This localized sealing approach maintains low pressure drop across the main filtration area while providing heat-resistant sealing where needed.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The carbon fiber felt is a porous material that allows some air permeability. This porosity reduces the pressure drop compared to solid sealing materials, while the carbon fiber structure provides the necessary heat resistance for regeneration cycles.

Inventive Principle:
Principle #31Porous materials

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 use of carbon fiber felt as a sealing material enhances the regeneration properties of the air filter assembly, enabling multiple regeneration cycles, reducing costs, and improving sustainability by maintaining filtration efficiency and extending the service life of the filter.

Implementation Method 1

a heat resistant sealing material between the adsorbent panel and the frame, which is a carbon fiber felt material arranged between the air permeable adsorbent panel and the frame so as to fill the distance therebetween, thereby preventing leakage of unfiltered air

Methodology Applied
Scientific EffectPhysical barrier sealing:

Implementation Method 2

the panel comprising a heat resistant structure comprising a heat resistant porous adsorbent material for adsorbing airborne molecular contamination

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 3

molecular filters and filter elements... for removing Airborne Molecular Contamination (AMC)

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 4

regeneration can be performed with adequate result by subjecting the filter to hot air treatment in order to remove the molecular contamination absorbed by the filter

Methodology Applied
Scientific EffectDesorption: Desorption

Implementation Method 5

the panel comprising a heat resistant structure comprising a heat resistant porous adsorbent material for adsorbing airborne molecular contamination and being configured to be regenerated by desorption

Methodology Applied
Scientific EffectThermal desorption:

Data Source

PatentEP4049744A1Regenerable air filter
Publication Date: 2022.08.31 CAMFIL AB
  • EP4049744A1 patent drawingFigure 1a
  • EP4049744A1 patent drawingFigure 1b
  • EP4049744A1 patent drawingFigure 2a~2b

AI summary

A heat resistant regenerable air filter assembly for an air supplying application, comprising an air permeable adsorbent panel (1) mounted in a frame (2), said panel comprising a heat resistant structure comprising a heat resistant porous adsorbent material for adsorbing molecular contamination and being configured to be regenerated by desorption, and said air filter assembly comprising a heat resistant sealing material (3) between the adsorbent panel and the frame, where the heat resistant sealing material is a carbon fiber felt material arranged between the air permeable adsorbent panel and the frame so as to fill the distance therebetween, thereby preventing leakage of unfiltered air through the heat regenerable air filter assembly; and a method (100) of regenerating the air filter assembly.