Eutectic Plug Manifold Venting for Heat-Reliable Shutoff Valves

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Solution Overview

Problem

Servo valves in aircraft engine bleed air systems fail unpredictably during extreme heat conditions, causing shutoff valves to remain open and potentially compromising engine safety.

Innovation Solution

A valve assembly with a manifold and eutectic plug configuration, where a thermal spacer and heat fins are used to maintain the eutectic plug in a solid state during normal operation, and it melts to vent the manifold exhaust conduit during a fire, ensuring the servo valve can close the shutoff valve.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the eutectic plug is positioned close to the manifold exhaust port to enable rapid venting during fire, then the response time during fire improves, but the plug temperature increases during normal operation causing unpredictable failure

Engineering Contradiction:
Improvepredictable operation of shutoff valveVSAvoidplug temperature during normal operation
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The patent introduces a thermal spacer as an intermediary component positioned between the manifold and the valve body. This thermal spacer acts as a thermal barrier that isolates the eutectic plug from excessive heat during normal operation, preventing the plug from reaching its melting point during regular high-temperature operation while still allowing rapid venting when needed for fire safety.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The manifold assembly is segmented into distinct thermal zones. The thermal spacer creates a physical and thermal separation between the hot manifold exhaust port area and the valve body containing the eutectic plug. This segmentation allows different parts of the assembly to operate at different temperatures appropriate for their function.

Inventive Principle:
Principle #1Segmentation

2Temperature

If the manifold height is increased to accommodate thermal management components, then thermal control of the eutectic plug improves, but the overall valve assembly height increases

Engineering Contradiction:
Improveeutectic plug temperature controlVSAvoidvalve assembly height
Core Design Contradiction:
TemperatureVSLength of stationary object

Solution Approach 1:

The patent redistributes thermal management functions across multiple dimensions rather than concentrating them in a single vertical direction. Heat fins extend radially outward from the manifold exhaust conduit to provide thermal management in the radial dimension, while the thermal spacer provides thermal isolation in the axial dimension. This multi-dimensional approach to thermal management achieves effective temperature control without requiring excessive height in any single direction.

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 ensures predictable operation of the shutoff valve by maintaining the eutectic plug in a solid state under normal conditions and allowing it to fail safely during a fire, ensuring the servo valve can close the shutoff valve, thus preventing compressor gases from reaching critical subsystems.

Implementation Method 1

a eutectic plug disposed within the manifold exhaust conduit at the manifold exhaust port, and configured to melt at a predetermined temperature

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

A valve assembly with a manifold and eutectic plug configuration, where a thermal spacer and heat fins are used to maintain the eutectic plug in a solid state during normal operation

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 3

heat fins are used to maintain the eutectic plug in a solid state during normal operation

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Data Source

PatentEP3904743B1Valve assembly configured with manifold having eutectic plug
Publication Date: 2023.04.26 HAMILTON SUNDSTRAND CORP
  • EP3904743B1 patent drawingFigure 1
  • EP3904743B1 patent drawingFigure 2
  • EP3904743B1 patent drawingFigure 3

AI summary

Disclosed is a valve assembly with: a valve body (110) defining valve inlet (120) and outlet ports (130); a manifold (160) connected to the valve outlet port, the manifold includes: a manifold inlet body portion (170) defining: a manifold internal surface (200) forming a manifold channel (210); and a first manifold external surface (180) defining a manifold inlet opening (190) that opens to the manifold channel, the manifold channel is fluidly coupled to the valve outlet port via the manifold inlet opening; a manifold outlet port (230), and a manifold outlet conduit (240) extending from the manifold inlet body portion to the manifold outlet port; a manifold exhaust port (260), and a manifold exhaust conduit (270) extending from the manifold inlet body portion to the manifold exhaust port, the manifold exhaust and outlet conduits are fluidly coupled to each other via the manifold channel, heat fins (290) extend from the manifold exhaust conduit; and a eutectic plug (300) disposed within the manifold exhaust conduit.