Introduction to Flame Arresters

A Comprehensive Guide on Flame Arresters and Their Applications

Flame arresters, also known as arrestors, are crucial devices used to prevent larger fires or explosions by allowing gas to pass through while stopping flames. With their wide range of applications across various industries, understanding how flame arresters work and their limitations is essential.

Exploring Modern Flame Arresters

Since their inception, flame arresters have undergone significant advancements to cater to diverse industry needs. All flame arresters operate on the same principle: removing heat from flames as they attempt to travel through narrow passages with heat-conductive walls. For instance, most manufacturers use crimped metal ribbons to create layers in their flame arresters.

Diverse Industrial Applications

Flame arresters find extensive use in industries such as refining, pharmaceuticals, chemicals, petrochemicals, pulp and paper, oil exploration and production, sewage treatment, landfills, mining, power generation, and bulk liquids transportation. These applications involve various equipment configurations and gas mixtures, including exothermic reactions other than oxidation.

Understanding the Functioning of Flame Arresters

Flame arresters are passive devices without any moving parts. They prevent flames from propagating from the exposed side to the protected side using wound crimped metal ribbon flame cell elements. These elements create a matrix of uniform openings designed to absorb and quench the flame’s heat, acting as an extinguishing barrier for ignited vapor mixtures.

In-Line Deflagration or Detonation Flame Arresters

Another category of flame arresters is the in-line variety, also known as deflagration and detonation flame arresters. These units are installed in pipes to prevent flames from passing through. In-line flame arresters are commonly used in systems that collect gases emitted by liquids and solids, typically referred to as vapor control systems. These systems aim to prevent potential catastrophic damage caused by ignition and subsequent flame propagation.

Selection Considerations for In-Line Flame Arresters

Selecting appropriate in-line flame arresters poses several challenges due to the dynamic nature of confined flames. Deflagration and detonation states involve high-pressure conditions and rapid flame movement, requiring flame arresters to absorb heat more efficiently. Moreover, overdriven detonation shockwaves exert immense pressure on the arresters. Therefore, selecting structurally superior flame arresters with the capability to withstand these extreme conditions is crucial.

End-of-Line Flame Arresters: Controlling Atmospheric Explosions

End-of-line deflagration flame arresters are specifically designed to prevent unconfined flame propagation, commonly known as atmospheric explosions. These arresters are easily attached to process or tank connections and employ simple technology, typically using a single element of crimped wound metal ribbon to quench the flame.

When selecting an end-of-line flame arrester, factors such as gas hazardous group designation, flame stabilization performance, process gas temperature, pressure drop, material compatibility, connection type and size, and instrumentation requirements should be considered.

API 2000 4.5.2 Design Options for Explosion Prevention

API 2000 4.5.2 emphasizes the importance of flame arresters in reducing the risk of flame transmission in open vent lines or pressure/vacuum valve inlets. However, it cautions against the potential tank damage caused by arrester plugging if not properly maintained. ISO 16852, NFPA 69, TRbF 20, EN 12874, FM 6061, and USCG 33 CFR 154 provide additional information on flame arresters. Consulting manufacturers is recommended for accurate selection and assessing potential effects on venting systems.

For a comprehensive and accurate selection of flame arresters, considerations such as piping configuration, operating pressure and temperature, oxygen concentration, compatibility with explosive gas groups, and material composition must be evaluated.

References: www.pressuresystems.com.au and www.enardo.com