Bicomponent Filter Media Pack for High Velocity Air Filtration

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Solution Overview

Problem

Conventional air filtration systems for high velocity applications, such as aviation inlet barrier filtration, face challenges with clogged and dirty filters requiring lengthy cleaning cycles and the use of oil-wetted media, which is environmentally, time, and cost burdensome, while lacking effective solutions for robust yet thin filter media that can efficiently separate particulates at high air intake rates.

Innovation Solution

A filter media pack composed of a composite stack of high loft and low loft bicomponent fibers, supported by perforate layers, allowing for easy cleaning with plain water and reuse, without the need for oil, and capable of withstanding multiple cycles of washing and reuse in demanding high velocity air filtration applications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional oil-wetted media is used for high velocity air filtration, then filtration efficiency is improved, but cleaning time and environmental burden increase substantially

Engineering Contradiction:
Improvefiltration efficiencyVSAvoidcleaning cycle time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent changes the chemical parameter of the filter media from oil-wetted to hydrophilic (water-loving) bicomponent fibers. This parameter change enables the media to be cleaned with plain water instead of requiring lengthy drying cycles after oil-based cleaning, reducing cleaning time from 24+ hours to significantly shorter periods while maintaining filtration efficiency through the unique fiber structure

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent enables the filter media to function as a reusable but easily replaceable component. By using hydrophilic bicomponent fibers that can be quickly cleaned with water or replaced, the system adopts a practical approach where the media can serve multiple cycles (short-lived in traditional sense) without environmental burden, eliminating the need for lengthy regeneration processes

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Strength

If filter media thickness is increased to handle high velocity air flow, then structural robustness is improved, but pressure drop increases

Engineering Contradiction:
Improvestructural robustnessVSAvoidpressure drop
Core Design Contradiction:
StrengthVSStress or pressure

Solution Approach 1:

The patent employs bicomponent fibers consisting of two different polymers with distinct properties: one component provides structural strength and rigidity to withstand high velocity air flow, while the other component maintains porosity and low pressure drop characteristics. This composite fiber structure allows the media to be both robust and permeable simultaneously

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies different properties to different regions of the filter media structure. The bicomponent fibers are arranged and oriented to provide localized structural support where needed while maintaining open pore structures in flow paths. The media can have varying loft, density, and fiber orientation in different zones to optimize both strength and airflow characteristics

Inventive Principle:
Principle #3Local quality

3Productivity

If filter media is made thin for easy cleaning, then cleaning speed is improved, but structural strength decreases

Engineering Contradiction:
Improvecleaning speedVSAvoidstructural strength
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The bicomponent fiber structure provides internal reinforcement within the thin media structure. One polymer component acts as a structural backbone providing tensile strength and dimensional stability, while the other component maintains the porous network for filtration and cleaning access. This allows thin media to be both cleanable and structurally sound

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent utilizes thin film-like structures made from the bicomponent nonwoven material that maintain structural integrity through the inherent properties of the composite fibers. The thin media can be flexed and handled easily for cleaning while the bicomponent structure prevents tearing or deformation, enabling rapid cleaning operations

Inventive Principle:
Principle #30Flexible shells and thin films

4Reliability

If multiple layers of filter media are stacked to increase filtration capacity, then particulate removal efficiency is improved, but device complexity increases

Engineering Contradiction:
Improveparticulate removal efficiencyVSAvoidmedia pack structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the filtration function into different zones within a single-layer or minimally layered structure. The bicomponent fibers are arranged with specific orientations, loft characteristics, and density gradients that create functional zones for capturing different particle sizes and types. This segmentation within a simplified structure achieves high removal efficiency without stacking multiple complex layers

Inventive Principle:
Principle #1Segmentation

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 efficient filtration of solid contaminants at high air velocities, maintaining efficiency and pressure drop performance across multiple use cycles, with rapid cleaning and drying capabilities, extending filter life and reducing environmental impact.

Implementation Method 1

The filter assemblies and methods of filtration of gaseous streams are employed in applications wherein it is desirable to remove solid contaminants from air... capable of depth loading with low pressure drop at air velocities of 100 fpm or more

Methodology Applied
Scientific EffectDepth loading filtration: Absorption (physical)

Implementation Method 2

The filter assemblies are easily cleaned with plain water and can be reused, in some embodiments, within 10 minutes after washing

Methodology Applied
Scientific EffectHydrophilicity: Hydrophile

Data Source

PatentEP2670507B1Filter media pack, filter assembly, and method
Publication Date: 2021.06.30 DONALDSON CO INC
  • EP2670507B1 patent drawingFigure 1
  • EP2670507B1 patent drawingFigure 2
  • EP2670507B1 patent drawingFigure 3~3A

AI summary

Disclosed are filter media packs having a single layer of a high loft filter media and a single layer of a low loft filter media, the filter media pack characterized by the absence of oil added to the filter media pack, the filter media pack capable of filtering air laden particulates from an air stream at greater than 94% efficiency at air stream flow rates of between about (100) feet per minute and (3000) feet per minute. Also disclosed are filter assemblies formed from the filter media pack, and methods of using the filter assemblies.