Flame Resistant Shield with Orthotropic Insulation

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Solution Overview

Problem

Current flame arrestor shields in aeronautics fail to provide continuous resistance at high temperatures due to decomposition of organic resins and rapid aging, leading to environmental hazards from asbestos dust and reduced protection for aircraft components.

Innovation Solution

A flame arrestor shield design featuring two insulating layers, one made of an orthotropic conductive material like Papyex and the other of low-conductivity mineral fibers, both resin-free, with a refractory metal sheet treated for oxidation resistance, and a titanium alloy support, ensuring efficient heat dissipation and structural integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If organic resin is used as binder in asbestos insulation layer, then insulation performance is improved, but decomposition occurs at high temperature causing rapid aging and environmental pollution

Engineering Contradiction:
Improveresistance to high temperatureVSAvoidcontinuous resistance at high temperature
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The invention removes the organic resin binder from the insulation layer, extracting the harmful component that causes decomposition at high temperatures. The insulation layer is made of asbestos fibers without any organic binder, eliminating the decomposition problem while maintaining insulation performance through the fibrous structure alone.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention creates an inert environment within the insulation layer by using only inorganic asbestos fibers without organic components. This inert composition prevents chemical decomposition reactions that would occur with organic resins at high temperatures, ensuring long-term stability and reliability.

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

2Temperature

If asbestos insulation layer with organic binder is used, then thermal insulation is improved, but binder decomposition leads to loss of mechanical strength and structural integrity

Engineering Contradiction:
Improvethermal insulationVSAvoidmechanical strength
Core Design Contradiction:
TemperatureVSStrength

Solution Approach 1:

The organic binder is completely removed from the insulation layer composition. The mechanical strength and structural integrity are maintained through the interlocking fibrous structure of asbestos alone, without relying on organic binders that decompose and cause strength loss.

Inventive Principle:
Principle #2Taking out (Extraction)

3Object-affected harmful factors

If asbestos shield is used for flame protection, then flame resistance is improved, but disassembly causes asbestos dust dispersion creating environmental hazards

Engineering Contradiction:
Improveflame protectionVSAvoidasbestos dust dispersion
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The invention redesigns the shield structure to be reusable and maintainable without disassembly. The opposite walls are designed to be removable and replaceable as complete units, allowing the asbestos insulation layer to remain intact and bound within the structure throughout its service life, preventing dust dispersion during maintenance operations.

Inventive Principle:
Principle #34Discarding and recovering

4Object-affected harmful factors

If thick insulation layers are used to withstand torch flame, then flame resistance is improved, but shield bulk and mass increase

Engineering Contradiction:
Improveflame resistanceVSAvoidshield mass
Core Design Contradiction:
Object-affected harmful factorsVSWeight of stationary object

Solution Approach 1:

The invention uses a composite structure combining asbestos insulation layer with opposite walls made of heat-resistant materials. This composite design provides enhanced flame resistance through the combined properties of the materials, allowing thinner overall construction while maintaining protection against torch flames, thereby reducing mass compared to purely thick insulation designs.

Inventive Principle:
Principle #40Composite 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 shield effectively withstands high temperatures and oxidative environments, preventing flame propagation while avoiding asbestos-related environmental issues and maintaining structural integrity, thus providing reliable protection for aircraft components.

Implementation Method 1

a first insulating layer, said first layer being able to diffuse heat in the plane formed by said layer while being insulating in its thickness

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

a first insulating layer, said first layer being able to diffuse heat in the plane formed by said layer while being insulating in its thickness

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 3

one of said opposite walls which covers said first layer, being made of an antioxidant refractory material or of which at least the face intended to be exposed to the flames is covered with a material preventing the oxidation of this face

Methodology Applied
Scientific EffectOxidation resistance: Oxidation

Implementation Method 4

said second insulating layer is an insulating layer having a thermal conductivity of less than 1 W.m-1

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP2753810B1Improved flame resistant shield
Publication Date: 2018.11.07 ARIANEGRP SAS
  • EP2753810B1 patent drawingFigure 1~2

AI summary

The subject matter of the invention is a flame resistant shield. According to the invention, this shield comprises two opposing walls between which are positioned at least: - a first insulating layer (4), said first layer (4) being capable of distributing heat in the plane formed by said layer and being insulating across its thickness, - a second insulating layer (5), - one (2) of said opposing walls which covers said first layer (4) being produced from a refractory antioxidant material or having at least the surface intended to be exposed to flames covered with a material preventing this surface from being oxidised, - the other wall (3) being a support.