Regenerable Pleated Filter Media for AMC Removal

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Solution Overview

Problem

Current filtration technologies for removing Airborne Molecular Contamination (AMC) in clean rooms face issues such as poor adsorption performance, high pressure drop, dusting, and the need for frequent filter replacements, especially in high-contamination environments, and existing regenerable filters are not suitable for clean room use due to particle shedding and increased energy costs.

Innovation Solution

A regenerable pleated filter media using activated carbon or polymer adsorbents enclosed between non-woven layers with a heat-resistant grid, allowing for regeneration at temperatures above 100°C, which prevents deformation and maintains low pressure drop, and can be used without additional particle filters, ensuring cleanliness and efficiency in clean room environments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If bulk adsorbent packed bed filters are used to achieve reasonable service times in high-contamination environments, then filtration duration is improved, but pressure drop increases and energy costs increase

Engineering Contradiction:
Improveservice timeVSAvoidpressure drop
Core Design Contradiction:
Duration of action of moving objectVSStress or pressure

Solution Approach 1:

The patent uses a pleated filter structure with porous adsorbent material distributed throughout the pleats, creating a large surface area with controlled porosity that allows gas flow while capturing contaminants, achieving long service life without high pressure drop

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The pleated configuration transforms a two-dimensional flat filter into a three-dimensional structure with extended surface area, allowing increased adsorbent capacity and longer service time while maintaining low pressure drop through the pleat geometry

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Duration of action of moving object

If bulk adsorbent packed bed filters are used to achieve reasonable service times, then filtration duration is improved, but energy costs increase

Engineering Contradiction:
Improveservice timeVSAvoidenergy costs
Core Design Contradiction:
Duration of action of moving objectVSUse of energy by stationary object

Solution Approach 1:

The porous pleated structure provides efficient contaminant capture with low flow resistance, reducing the energy required to maintain airflow while extending filter service life

Inventive Principle:
Principle #31Porous materials

3Stress or pressure

If carbon fiber filters are used to achieve low pressure drop, then fluid flow is improved, but particle shedding occurs

Engineering Contradiction:
Improvepressure dropVSAvoidparticle shedding
Core Design Contradiction:
Stress or pressureVSObject-generated harmful factors

Solution Approach 1:

The patent combines adsorbent material with a non-woven fabric substrate to create a composite structure that captures particles effectively while preventing fiber shedding, eliminating the contamination problem of pure carbon fiber filters

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The porous non-woven fabric substrate provides structural integrity and particle capture without the shedding issues of carbon fibers, maintaining low pressure drop while ensuring clean room compatibility

Inventive Principle:
Principle #31Porous materials

4Stress or pressure

If adsorbent powder slurry-coated nonwovens are used to achieve low pressure drop, then fluid flow is improved, but adsorption performance deteriorates

Engineering Contradiction:
Improvepressure dropVSAvoidadsorption performance
Core Design Contradiction:
Stress or pressureVSReliability

Solution Approach 1:

The patent creates a composite structure where adsorbent particles are embedded within or coated on non-woven fabric, providing both low flow resistance and high adsorption capacity through the synergistic combination of materials

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The pleated configuration increases the surface area of the slurry-coated nonwoven, enhancing adsorption capacity while maintaining the low pressure drop characteristic of the nonwoven substrate

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

5Stress or pressure

If honeycomb filters are used to achieve low pressure drop, then fluid flow is improved, but adsorption performance deteriorates

Engineering Contradiction:
Improvepressure dropVSAvoidadsorption performance
Core Design Contradiction:
Stress or pressureVSReliability

Solution Approach 1:

The pleated structure provides a flexible alternative to rigid honeycomb geometry, achieving similar flow efficiency with enhanced adsorption capacity through increased surface area and adaptable pleat dimensions

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

6Reliability

If pleated filters with high adsorbent content are used to improve adsorption performance, then filtration efficiency is improved, but pressure drop increases

Engineering Contradiction:
Improvefiltration efficiencyVSAvoidpressure drop
Core Design Contradiction:
ReliabilityVSStress or pressure

Solution Approach 1:

The pleated configuration expands the filter surface area in the third dimension, allowing high adsorbent content for efficient contaminant capture while maintaining low pressure drop through the pleat geometry that facilitates airflow

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 provides long-lasting, low-pressure-drop filtration with reduced energy costs and no particle shedding, effectively removing AMC, including VOCs, while allowing for multiple regeneration cycles, thus lowering the cost of ownership and maintaining high filtration efficiency in clean room environments.

Implementation Method 1

The gas/vapour molecules diffuse inside the adsorbent, i.e. they move from area of high concentration to low concentration. As the internal surface of the adsorbent gets covered with gas/vapour molecules, the filter efficiency starts to decrease.

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 2

the simple possibility to vary number of pleats or pleat heights to vary the performance at will... when the effluent gas/vapour reaches an unacceptable level, the filter needs to be changed... Regenerable filters are known in fixed installations for instance twin beds of adsorbent that are alternately in service or under regeneration.

Methodology Applied
Scientific EffectDesorption: Desorption

Implementation Method 3

regeneration at temperatures above 100°C, which prevents deformation and maintains low pressure drop

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP2403626B1Regenerable pleated filter medium
Publication Date: 2015.07.15 CAMFIL AB
  • EP2403626B1 patent drawingFigure 1~2
  • EP2403626B1 patent drawingFigure 3
  • EP2403626B1 patent drawingFigure 4

AI summary

The present invention provides regenerable pleated media and filter elements and combinations thereof for use in a clean room environment for removal of airborne molecular contamination. Disclosed is a pleated filter media for a clean room environment wherein the pleated filter media comprises at least an adsorbent first layer of activated carbon or polymer wherein said activated carbon or polymer together with fibers and/or an adhesion agent is enclosed between two second layers of non woven with a grid positioned on at least one side of either of the second layers or incorporated in the first layer for preventing deformation of the pleated filter media when regenerated by a heated air flow above 1000C at 1 atm.