Curved Engine Fire Extinguisher with Pyrotechnic Piston Drive

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Solution Overview

Problem

Existing aircraft engine fire extinguishers using Halon gas are environmentally unsatisfactory due to high ozone depletion and global warming potential, require large masses of non-polluting liquid agents, and cause untargeted flooding and aerodynamic disturbances.

Innovation Solution

A pyrotechnic fire extinguisher with a non-polluting liquid agent is integrated into the engine nacelle, featuring a longitudinally curved body and piston with a gas generator protected by a thermal insulator, allowing precise targeting and minimal mass and aerodynamic disruption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If Halon gas is used as extinguishing agent, then extinguishing efficiency is improved, but environmental pollution increases

Engineering Contradiction:
Improveextinguishing efficiencyVSAvoidozone depletion and global warming potential
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The invention changes the physical state parameter of the extinguishing agent from gaseous (Halon) to liquid (non-polluting alternative), and uses a pyrotechnic gas generator to convert the liquid to gas at the point of use, thereby eliminating environmental pollution while maintaining extinguishing efficiency

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention extracts the harmful Halon gas from the system and replaces it with an environmentally friendly liquid agent, using a pyrotechnic generator to produce the necessary gas phase extinguishing agent locally, thus removing the source of environmental harm

Inventive Principle:
Principle #2Taking out (Extraction)

2Object-generated harmful factors

If non-polluting liquid agent is used, then environmental pollution is reduced, but mass of extinguishing agent required increases

Engineering Contradiction:
Improveenvironmental pollutionVSAvoidmass of extinguishing agent
Core Design Contradiction:
Object-generated harmful factorsVSQuantity of substance

Solution Approach 1:

The invention segments the extinguishing system into three separate components: a liquid storage chamber, a pyrotechnic gas generator, and a discharge mechanism. This allows the liquid agent to be stored compactly and converted to gas only when needed, reducing the total mass required while maintaining effective extinguishing concentration

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention utilizes phase transition by storing the extinguishing agent as a liquid in the storage chamber and using a pyrotechnic gas generator to rapidly convert it to gas phase at the point of discharge, thereby achieving high concentration extinguishing with reduced mass while avoiding environmental pollution of liquid agents

Inventive Principle:
Principle #36Phase transitions

3Reliability

If extinguisher is positioned close to engine, then extinguishing efficiency is improved, but thermal stress exposure increases

Engineering Contradiction:
Improveextinguishing efficiencyVSAvoidthermal stress exposure
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The phase transition from liquid to gas provided by the pyrotechnic generator creates a rapid expansion effect that protects the system from thermal stress, while the liquid state during storage allows for compact positioning near the engine without direct thermal exposure

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

The pyrotechnic gas generator acts as an intermediary between the liquid storage chamber and the engine fire, providing thermal protection while enabling the liquid agent to be converted to effective gas phase extinguishing agent at the point of use

Inventive Principle:
Principle #24Intermediary (Mediator)

4Ease of manufacture

If straight body shape is used, then manufacturing is simplified, but aerodynamic disturbance increases

Engineering Contradiction:
Improvebody manufacturingVSAvoidaerodynamic disturbance
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The invention applies curvature to the body shape to match the aerodynamic contours of the engine nacelle, reducing aerodynamic disturbance and turbulence in the air stream while maintaining manufacturing feasibility through curved surface formation

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 extinguisher achieves efficient fire extinguishing close to the engine with reduced mass and aerodynamic impact, using a compact design and precise agent delivery, maintaining operational capability after 15 minutes of fire.

Implementation Method 1

a gas generator capable of generating a gas in the pressurization chamber

Methodology Applied
Scientific EffectPyrotechnic reaction: Combustion

Implementation Method 2

the piston being configured to slide in the body between the first end and the second end of the body

Methodology Applied
Scientific EffectPressure-driven displacement: Pressure Gradient

Implementation Method 3

the body having a longitudinally curved shape between its first end and its second end, the piston having a curvilinear stroke between the first end and the second end of the body

Methodology Applied
Scientific EffectAerodynamic flow optimization: Boundary Layer

Implementation Method 4

The extinguishing agent has a strong endothermic power, which makes it an excellent thermal insulator

Methodology Applied
Scientific EffectEndothermic reaction: Endothermic Reaction

Implementation Method 5

By placing the gas generator in the piston, it is protected by the air or gas present in the pressurization chamber, which acts as a thermal insulator

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP4389236B1Curved fire extinguisher for an engine
Publication Date: 2025.08.06 ARIANEGRP SAS
  • EP4389236B1 patent drawingFigure 1~2
  • EP4389236B1 patent drawingFigure 3~4
  • EP4389236B1 patent drawingFigure 5~6

AI summary

The invention relates to a fire extinguisher (1) comprising at least: - a body forming a container extending longitudinally between a first end (2b) and a second end (2c) and enclosing a storage chamber (4) and a pressurization chamber (3) separated by a piston (5) adapted to slide within said body (2) between the first end (2b) and the second end (2c) of said body (2), an extinguishing agent being present in the storage chamber (4), and the storage chamber (4) comprising at least one outlet orifice (10), and - a gas generator adapted to generate a gas in the pressurization chamber (3). The piston (5) comprises the gas generator, and the body (2) has a longitudinally curved shape between its first end (2b) and its second end (2c), the piston (5) having a curvilinear stroke between the first end (2b) and the second end (2c) of the body (2).