Why Wont Carbon Dioxide Fire Extinguishers Put Out Magnesium Fires:- Carbon dioxide fire extinguishers are frequently a dependable option for fighting flames.
Magnesium fires, on the other hand, present a challenge for these extinguishers. Although they work well in many situations, carbon dioxide fire extinguishers are ineffective at putting out magnesium flames.
The reasons why carbon dioxide fire extinguishers are unsuccessful at putting out magnesium flames will be examined in this article, along with possible solutions.
We can safeguard the security of people working with magnesium and improve our capacity to combat these particular fire threats by being aware of the restrictions and looking into alternate options.
Understanding Magnesium Fires
Magnesium is a strong and light metal that is highly reactive. Construction, automobile, and aerospace use it often. Magnesium fires, which are started at incredibly high temperatures, emit great heat and bright white light.
Magnesium flames are difficult to put out due to their special properties.
How Carbon Dioxide Fire Extinguishers Work
In order to put out a fire, carbon dioxide fire extinguishers suffocate it by replacing oxygen, which is necessary for combustion. They are pressurized cylinders that are full of liquid carbon dioxide.
When released, the liquid CO2 quickly transforms into a gas and forms a cloud that suffocates the surrounding air with oxygen.
Limitations of Carbon Dioxide Fire Extinguishers
Although carbon dioxide fire extinguishers are useful in a variety of situations, they have some restrictions. When reactive metals like magnesium are involved in a fire, these extinguishers are ineffective.
Carbon dioxide extinguishers may not effectively put out flames when used on magnesium fires, and the fire may flare back up after the CO2 evaporates.
Why Carbon Dioxide Doesn’t Work on Magnesium Fires
Carbon dioxide and magnesium interaction:
Magnesium oxide and carbon are produced chemically when carbon dioxide is added to a magnesium fire. This interaction has the potential to increase the fire’s heat output.
Magnesium has a higher ignition temperature:
Magnesium has a high ignition temperature; it usually reaches 650 °C (1200 °F) or more. Even in its solid state as a snow-like substance, carbon dioxide cannot bring the temperature down low enough to stop the fire from rekindling.
Forming a shielding oxide layer:
Magnesium easily combines with airborne oxygen to generate a surface-protecting oxide layer. This layer halts additional oxidation and retards the spread of the fire. This barrier is not adequately broken down by carbon dioxide, allowing the fire to spread.
Alternative Fire Suppression Methods for Magnesium Fires
It takes sophisticated fire control techniques to put out magnesium fires. Alternatives to carbon dioxide fire extinguishers include the following:
Extinguishers classified as Class D:
These are intended especially for metal-reactive flames. Specialized powders found in Class D extinguishers, such as sodium chloride or graphite, smother the fire and stop the flow of combustible gases.
Specialized powders and sand:
Magnesium fires can be put out by using sand or some kind of dry powder, such as copper powder. These substances smother the fire, absorb heat, and keep oxygen from getting to the burning fuel.
Fire blankets and misting systems using water:
Small magnesium flames can be doused with fire blankets made of fiberglass or other flame-resistant materials. By cooling the burning substance, water mist systems, which spread tiny water droplets, can also put out fires.
Safety Precautions for Handling Magnesium Fires
The right training and safety measures are needed to handle magnesium fires. If you come across a magnesium fire, take the following actions:
Notify others and leave:- Ensure everyone’s safety by evacuating the area and alerting adjacent residents about the fire.
Contacting emergency services:- Call the appropriate emergency number and give all the necessary details to report the fire.
Utilize effective fire suppression techniques:- Use the appropriate fire suppression technique, such as a class D extinguisher or specialist powders, if you are trained and equipped and the fire is caused by magnesium.
Avoid using water:- Avoid using water to put out magnesium fires since it could speed up the combustion and cause explosions.
FAQs About Why Wont Carbon Dioxide Fire Extinguishers Put Out Magnesium Fires
Why do magnesium fires fail to be put out by carbon dioxide fire extinguishers?
Because the reaction between carbon dioxide and magnesium can release extra heat and increase the fire, carbon dioxide fire extinguishers are ineffective for magnesium flames.
What happens if a magnesium fire is put out with a carbon dioxide fire extinguisher?
The fire may restart when a carbon dioxide fire extinguisher leaves the vicinity.
Why isn’t carbon dioxide able to lower the magnesium ignition temperature?
Carbon dioxide is unable to sufficiently lower the high ignition temperature of magnesium, which is typically around 650 degrees Celsius (1200 degrees Fahrenheit).
What does burning magnesium build a protective layer out of?
When magnesium burns, it creates a protective oxide layer that reduces how well carbon dioxide puts out fires.
Exist any fire extinguishers created specifically to put out magnesium fires?
Class D extinguishers are specialty fire extinguishers made especially for putting out fires involving reactive metals like magnesium.
What alternative techniques are there for putting out magnesium fires?
Sand, fire blankets, water spray systems, and specific powders like sodium chloride or graphite are examples of alternative techniques.
Can magnesium flames be put out using water?
No, water shouldn’t be used to put out magnesium flames because it might speed up the reaction and cause explosions.
Do magnesium fires occur frequently?
Despite being very uncommon, magnesium fires can happen in fields like manufacturing, machining, or aerospace that use or handle the metal.
Why are magnesium fires difficult to put out?
High-temperature magnesium fires can be maintained by the metal’s propensity to react with oxygen. Additionally, the development of a shielding oxide layer makes it difficult to use conventional extinguishing techniques.
How should magnesium fires be handled in terms of safety?
Ensure personal safety, leave the location, call emergency services, and put out the fire using specialized magnesium fire suppression techniques.
Can different sorts of fires be put out with carbon dioxide fire extinguishers?
Yes, carbon dioxide fire extinguishers work well to put out a variety of flames, including those involving flammable liquids, electrical equipment, and some gases.
Magnesium fires – Episode 11 Video
Reference:
https://www.usfa.fema.gov/
https://en.wikipedia.org/wiki/Fire_extinguisher
Conclusion
While carbon dioxide fire extinguishers work well to put out a variety of fires, they are ineffective against magnesium fires because of the peculiar characteristics of magnesium.
It is essential to recognize the limitations of carbon dioxide extinguishers and alternate fire suppression techniques in order to protect those who work with magnesium.
Magnesium fires can be efficiently controlled by using the right methods and tools.