Aircraft Firewall Feedthrough Sealing for Maintainable Fire Zone Isolation

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Solution Overview

Problem

Existing feedthrough systems across firewalls in gas turbine engines are cumbersome and complicate maintenance tasks, requiring improvements for efficient communication and sealing between fire and non-fire zones.

Innovation Solution

Aircraft firewall feedthrough devices that sealingly accommodate feedthrough members through firewalls, using a plate attached with bolts and gaskets, with tubular portions and grommets to provide a secure and maintainable passage for fluid and electrical communication, while preventing flame and vapor migration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If existing feedthrough systems are used to provide electric and fluid communication across firewalls, then communication between fire and non-fire zones is established, but the systems become cumbersome and complicate maintenance tasks

Engineering Contradiction:
Improvemaintenance simplicityVSAvoidfeedthrough system complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The feedthrough system is divided into separate modular components including individual feedthrough elements, sealing elements, and support structures. Each component can be independently installed, inspected, and replaced, transforming a complex integrated system into manageable segments that simplify maintenance operations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The feedthrough device is designed as a universal multi-functional unit that simultaneously provides mechanical support, electrical communication, fluid passage, and fire sealing. This consolidation of multiple functions into a single standardized component reduces overall system complexity and simplifies maintenance by eliminating the need for separate components for each function.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If feedthrough members are installed through firewalls to enable communication, then electric and fluid lines can pass through, but the sealing effectiveness is compromised and flame migration risk increases

Engineering Contradiction:
Improvesealing effectivenessVSAvoidflame migration risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A dedicated sealing element acts as an intermediary component between the feedthrough member and the firewall. This sealing element is specifically designed to accommodate the feedthrough while maintaining fire barrier integrity, effectively mediating between the need for communication and the need for fire protection.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The sealing system incorporates flexible sealing elements that can deform to accommodate feedthrough members while maintaining continuous fire barrier coverage. These flexible sealing components conform to the feedthrough geometry and provide reliable sealing without compromising flame migration prevention.

Inventive Principle:
Principle #30Flexible shells and thin films

3Reliability

If complex feedthrough systems are used to ensure proper sealing and communication, then fire and fluid zone separation is maintained, but installation and maintenance time increases

Engineering Contradiction:
Improvefire zone separationVSAvoidmaintenance time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

Multiple critical functions including mechanical support, electrical insulation, fluid sealing, and fire barrier integration are merged into a single pre-assembled feedthrough unit. This consolidation eliminates the need for complex field assembly procedures and reduces maintenance time by allowing the entire assembly to be replaced as one unit if needed.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The feedthrough system is pre-configured and pre-assembled with all necessary components (feedthrough elements, sealing elements, support structures) properly positioned and secured before installation. This preliminary preparation ensures that fire zone separation is maintained from the outset and eliminates time-consuming adjustment procedures during installation or maintenance.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3957842B1Aircraft firewall feedthrough device
Publication Date: 2024.07.31 PRATT & WHITNEY CANADA CORP
  • EP3957842B1 patent drawingFigure 1
  • EP3957842B1 patent drawingFigure 2A
  • EP3957842B1 patent drawingFigure 2B

AI summary

An aircraft firewall feedthrough device (12) for accommodating a feedthrough member (34) extending through an aperture of a firewall (32) of an aircraft is provided. The device includes a plate (38) configured to be attached to the firewall, a first tubular portion (46A) extending from a first side of the plate, a second tubular portion (46B) extending from a second side of the plate, and a grommet (50A, 50B). The plate includes a feedthrough aperture (44). The first tubular portion, the second tubular portion and the feedthrough aperture cooperatively define a through passage (48) for accommodating the feedthrough member. The grommet is retained inside the through passage. The grommet includes a hole (56) for accommodating the feedthrough member through the grommet.