Metal Mesh Flame Arrestor for Flammable Refrigerant Safety

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Solution Overview

Problem

The refrigeration industry faces challenges in preventing the ignition and propagation of flammable refrigerants, such as hydrofluorocarbons and hydrocarbons, which can lead to fires when leaked and exposed to ignition sources in refrigerant systems, particularly in mobile and stationary air conditioning and refrigeration systems, due to environmental regulations and the potential for global phase-out of certain refrigerants with high global warming potential.

Innovation Solution

A metal mesh flame arrestor is positioned between the refrigerant source and ignition sources to prevent the propagation of flames, using materials like 316 stainless steel, 304 stainless steel, carbon steel, or aluminum with specific mesh sizes and configurations to stop flame fronts effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If flammable refrigerants (HFO-1234yf, HFC-134a) are used to achieve low GWP and comply with environmental regulations, then environmental compliance is improved, but the risk of fire propagation when leaked and exposed to ignition sources increases

Engineering Contradiction:
Improveenvironmental complianceVSAvoidfire propagation risk
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

A metal mesh flame arrestor is positioned between the refrigerant system and potential ignition sources (exhaust manifold, catalytic converter) to act as an intermediary barrier. The mesh structure with specific opening sizes (0.028-0.060 inches) physically interrupts flame propagation while allowing refrigerant flow, preventing direct contact between leaked refrigerant and ignition sources.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The flame arrestor creates a protected zone by cooling flames through thermal conduction to the metal mesh and diluting oxygen concentration within the mesh structure, effectively creating a locally inert environment that prevents combustion of leaked refrigerant.

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

2Reliability

If metal mesh flame arrestors are positioned between refrigerant sources and ignition sources to prevent flame propagation, then fire safety is improved, but system complexity increases

Engineering Contradiction:
Improvefire safetyVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The flame arrestor utilizes a metal mesh with controlled porosity (opening sizes of 0.028-0.060 inches) that allows refrigerant flow while blocking flame propagation. The porous structure provides multiple flame quenching paths without requiring complex active components, maintaining system simplicity while enhancing safety.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The flame arrestor is implemented as a simple, inexpensive passive safety component that can be easily installed and replaced if necessary. The metal mesh construction uses common materials (stainless steel, aluminum) that are cost-effective and do not require complex control systems or maintenance.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 metal mesh flame arrestor effectively contains and mitigates the spread of flames from refrigerant leaks, reducing the risk of fire propagation and damage, as demonstrated by tests with various refrigerant compositions and configurations, enhancing safety in refrigerant systems.

Implementation Method 1

The metal mesh flame arrestor effectively contains and mitigates the spread of flames from refrigerant leaks

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

positioning a metal mesh flame arrestor between said refrigerant source and said ignition source

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Data Source

PatentEP4101508A1Methods of reducing flame propogation in systems with a flammable refrigerant
Publication Date: 2022.12.14 THE CHEMOURS CO FC LLC
  • EP4101508A1 patent drawingFigure 1
  • EP4101508A1 patent drawingFigure 2
  • EP4101508A1 patent drawingFigure 3

AI summary

The present invention provides methods for reducing the propagation of a flame to or from a refrigerant source (40) and an ignition source (112, 116, 120a) in or adjacent to a cooling system, comprising positioning a metal mesh flame arrestor (22, 120) between said refrigerant source and said ignition source (112, 18). The methods allow the use of flammable refrigerants with reduced risk of fire.