Difference between Jet Fire, Pool Fire and Flash Fire

Understanding Industrial Fires: Jet Fires, Pool Fires, and Flash Fires
Industrial fires are a serious concern in various sectors, particularly in petrochemical and manufacturing industries. Three prominent types of industrial fires are jet fires, pool fires, and flash fires. Understanding these types is crucial for effective safety management and disaster prevention. In this blog post, we’ll dive into each type of fire, exploring their characteristics, examples, and safety implications.
1. Jet Fires
What Are Jet Fires?
Jet fires occur when flammable liquids or gases are ejected from a small opening, such as a nozzle or crack, and ignite. Imagine a powerful garden hose spraying water-if the water were flammable and ignited, it would create a jet fire. These fires produce long, narrow flames that can extend up to 50 meters or more.
Characteristics of Jet Fires
Flame Shape and Reach: The flame from a jet fire typically resembles a long, narrow cylinder. In calm air, the flame remains vertical. However, when wind is present, the flame tilts and extends beyond its initial boundary, similar to how a water stream from a hose bends in the wind.
Heat and Radiation: Jet fires release intense heat and thermal radiation, which can pose severe risks to both life and property. The energy transmitted by these fires can cause significant damage to equipment and infrastructure.
Notable Example
One of the most dramatic examples of a jet fire is the Piper Alpha Oil Platform disaster in 1988. The platform, located in the North Sea, was destroyed by a series of violent explosions and jet flames from a gas riser. The disaster resulted in 128 fatalities out of 229 crew members. The flames, reaching up to 100 meters high, made it impossible for rescue helicopters to approach, and many survivors had to jump into the rough sea to escape.
2. Pool Fires
What Are Pool Fires?
Pool fires occur when a flammable liquid spills and ignites, forming a stationary flame over the liquid. This type of fire can happen on the ground, in storage tanks, or on water surfaces. Picture a puddle of gasoline that catches fire-this is akin to a pool fire.
Characteristics of Pool Fires
Flame Shape and Behavior: The flame from a pool fire is usually circular or rectangular, depending on the shape of the spill. In a bund (a containment area), the fire takes on a cylindrical shape. In the absence of wind, the flame is upright, but wind can cause it to tilt and drag beyond the bund’s edge.
Impact and Damage: Pool fires can be extensive, especially if the spilled liquid covers a large area. They can cause severe burns and rapid depletion of oxygen. While quick control can minimize damage to main plant equipment, electrical cables and sensitive equipment can be extensively damaged.
Notable Example
The Cleveland, Ohio, fire in 1944 is a notable example of a pool fire. Approximately 3,000 tons of LNG spilled from several storage tanks, leading to widespread fires. This incident resulted in 128 deaths and 400 injuries, demonstrating the destructive potential of pool fires.
3. Flash Fires
What Are Flash Fires?
Flash fires, or vapour cloud fires, occur when a cloud of flammable vapours mixes with air and ignites. This type of fire burns with a stationary flame at subsonic speeds and does not generate significant overpressure. Think of it as a sudden, intense burst of flames in a vapour-filled environment.
Characteristics of Flash Fires
Ignition and Flame Behavior: Flash fires result from the ignition of a vapour cloud formed from a leak or spill. Unlike jet fires or pool fires, flash fires do not involve significant overpressure, which means they burn without causing explosions.
Temperature and Effects: Flash fires can reach temperatures between 550 to 1050°C, and potentially higher. They can cause severe burns, rapid oxygen depletion, and damage to equipment and infrastructure.
Notable Example
Significant flash fire incidents include the Port Newark fire in 1951 and the Mexico City fire in 1984. These incidents involved large vapour clouds that ignited, causing extensive damage and casualties.
Conclusion
Understanding jet fires, pool fires, and flash fires is essential for effective safety management in industrial settings. Each type of fire has distinct characteristics and hazards:
Jet Fires: Long, narrow flames extending from small openings.
Pool Fires: Stationary flames burning over spilled liquids.
Flash Fires: Sudden bursts of flames from ignited vapour clouds.
By studying these fire types and learning from past incidents, we can develop better safety protocols and prevention strategies to protect people and property from the devastating impacts of industrial fires.
If you have any questions or need further information on these fire types, feel free to leave a comment or contact us. Stay safe and informed!