Composite Filter Media with Nanofiber Layer for Gas Turbine Filtration

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing composite nonwoven filter media with nanofiber layers are vulnerable to mechanical stress, prone to shedding, and have low filtration efficiency, allowing fine dust particulates to penetrate, leading to increased pressure drop and turbine blade fouling in gas turbines.

Innovation Solution

A composite filter media is created using a spunbond process with embossing calender rolls to form a nonwoven fabric with a unique bond pattern and a nanofiber layer applied via electro-blown spinning, enhancing filtration efficiency and durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a lightweight nanofiber layer is applied to filter media, then filtration efficiency is improved, but mechanical strength and durability deteriorate

Engineering Contradiction:

Improvefiltration efficiencyVSAvoidmechanical strength

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The patent creates a composite structure combining a robust spunbond substrate with an electrospun nanofiber layer. The substrate provides mechanical strength while the nanofiber layer provides filtration efficiency, achieving both requirements simultaneously through material composition rather than compromise

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent transitions from conventional two-dimensional planar filtration to three-dimensional hierarchical structure with the nanofiber layer adding vertical dimension. This multi-layered approach allows the substrate to handle mechanical loads while the nanofiber layer captures particles, resolving the strength-efficiency tradeoff

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If conventional electro-spun nanofiber layers are used, then filtration efficiency is improved, but fiber shedding increases

Engineering Contradiction:

Improvefiltration efficiencyVSAvoidfiber shedding

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces conventional electrospinning with electro-blown spinning that uses compressed air injection to form nanofibers. This mechanical assistance creates stronger fiber-substrate bonds through physical entanglement and adhesion, eliminating fiber shedding while maintaining filtration efficiency

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces compressed air as an intermediary medium during fiber formation. The air stream facilitates better distribution and bonding of nanofibers to the substrate, creating a more stable attachment that prevents shedding during operation

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If known filter media are used, then initial filtration efficiency is achieved, but pressure drop increases over time due to dust penetration

Engineering Contradiction:

Improvefiltration efficiencyVSAvoidpressure drop

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent applies a nanofiber coating beforehand to the spunbond substrate, creating a protective barrier that prevents dust penetration from the start. This pre-protection eliminates the progressive pressure drop increase that occurs with conventional media, maintaining stable performance throughout operation

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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 achieves a 15% increase in filtration efficiency and a 30% reduction in pressure drop, providing a more durable filter media with a higher quality factor and effective reverse pulse cleaning, reducing turbine downtime and blade fouling.

Implementation Method 1

applying a nanofiber layer by electro-blown spinning a polymer solution to form a plurality of nanofibers on at least one side of the nonwoven fabric mat

Methodology Applied

Scientific EffectElectrostatic deposition: Electrostatic Deposition

Implementation Method 2

calendering the nonwoven fabric mat with embossing calender rolls to form a bond area pattern comprising a plurality of substantially parallel discontinuous lines of bond area to bond the synthetic fibers together

Methodology Applied

Scientific EffectThermal compression bonding:

Data Source

PatentEP2321028B1Method of manufacturing a composite filter media

Publication Date: 2018.02.28 EI DU PONT DE NEMOURS & CO

Figure 1
Figure 2~3
Figure 4~5

AI summary

A method of making a composite filter media includes, in an exemplary embodiment, forming a nonwoven fabric mat that includes a plurality of synthetic fibers by a spunbond process, and calendering the nonwoven fabric mat with embossing calender rolls to form a bond area pattern comprising a plurality of substantially parallel discontinuous lines of bond area to bond the synthetic fibers together to form a nonwoven fabric, the nonwoven fabric having a filtration efficiency of about 35% to less than 50%, measured in accordance with EN 1822 (1998) test procedure. The method also includes applying a nanofiber layer by electro-blown spinning a polymer solution to form a plurality of nanofibers on at least one side of the nonwoven fabric mat to form the composite filter media, the composite filter media having a minimum filtration efficiency of about 70%, measured in accordance with EN 1822 (1998) test procedure.