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twinky64

Fire

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I know that fire needs the existence of heat, oxygen, and a fuel. To make fire, it is a chemical or molecular reaction.

 

I was thinking, does fire need heat to burn or is heat just a byproduct of fire. I understand fire can be produced from heat (super excited molecules containing a large amount of kinetic energy), however, can a fire exist in a freezer? I'm thinking, intuitively, that it will not go out.

 

I am majoring in Mechanical Engineering and as I saw the fire on the news last night in Porter Ranch, I'm thinking to myself how primitive our fire fighting tools and methods are. I asked a few classmates of mine, "would you take out a small bush fire with a spray bottle or water balloons?" So far I've gotten water balloons as an answer except one answered with a spray bottle. I argued that it will turn into vapor before it does anything to the fire. He countered argued saying that not only does water suffocate the fire, it "cools it down". Then I asked myself "does fire need heat to continue burning?"

 

Any thoughts?

Edited by twinky64

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I know that fire needs the existence of heat, oxygen, and a fuel. To make fire, it is a chemical or molecular reaction.

 

I was thinking, does fire need heat to burn or is heat just a byproduct of fire. I understand fire can be produced from heat (super excited molecules containing a large amount of kinetic energy), however, can a fire exist in a freezer? I'm thinking, intuitively, that it will not go out.

 

I am majoring in Mechanical Engineering and as I saw the fire on the news last night in Porter Ranch, I'm thinking to myself how primitive our fire fighting tools and methods are. I asked a few classmates of mine, "would you take out a small bush fire with a spray bottle or water balloons?" So far I've gotten water balloons as an answer except one answered with a spray bottle. I argued that it will turn into vapor before it does anything to the fire. He countered argued saying that not only does water suffocate the fire, it "cools it down". Then I asked myself "does fire need heat to continue burning?"

 

Any thoughts?

Fire is the heat and light energy released during a chemical reaction, in particular a combustion reaction. Depending on the substances alight, and any impurities outside, the color of the flame and the fire's intensity might vary. Fire in its most common form can result in conflagration, and has the potential to cause physical damage through burning.

[edit] Chemical reaction

 

The fire tetrahedronFires start when a flammable and/or a combustible material with an adequate supply of oxygen or another oxidizer is subjected to enough heat and is able to sustain a chain reaction. This is commonly called the fire tetrahedron. No fire can exist without all of these elements being in place.

 

Once ignited, a chain reaction must take place whereby fires can sustain their own heat by the further release of heat energy in the process of combustion and may propagate, provided there is a continuous supply of an oxidizer and fuel.

 

Fire can be extinguished by removing any one of the elements of the fire tetrahedron. Fire extinguishing by the application of water acts by removing heat from the fuel faster than combustion generates it. Application of carbon dioxide is intended primarily to starve the fire of oxygen. A forest fire may be fought by starting smaller fires in advance of the main blaze, to deprive it of fuel. Other gaseous fire suppression agents, such as halon or HFC-227, interfere with the chemical reaction itself.

Edited by Bikeman982

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I know that fire needs the existence of heat, oxygen, and a fuel. To make fire, it is a chemical or molecular reaction.

 

I was thinking, does fire need heat to burn or is heat just a byproduct of fire. I understand fire can be produced from heat (super excited molecules containing a large amount of kinetic energy), however, can a fire exist in a freezer? I'm thinking, intuitively, that it will not go out.

 

I am majoring in Mechanical Engineering and as I saw the fire on the news last night in Porter Ranch, I'm thinking to myself how primitive our fire fighting tools and methods are. I asked a few classmates of mine, "would you take out a small bush fire with a spray bottle or water balloons?" So far I've gotten water balloons as an answer except one answered with a spray bottle. I argued that it will turn into vapor before it does anything to the fire. He countered argued saying that not only does water suffocate the fire, it "cools it down". Then I asked myself "does fire need heat to continue burning?"

 

Any thoughts?

Fire is the heat and light energy released during a chemical reaction, in particular a combustion reaction. Depending on the substances alight, and any impurities outside, the color of the flame and the fire's intensity might vary. Fire in its most common form can result in conflagration, and has the potential to cause physical damage through burning.

[edit] Chemical reaction

 

The fire tetrahedronFires start when a flammable and/or a combustible material with an adequate supply of oxygen or another oxidizer is subjected to enough heat and is able to sustain a chain reaction. This is commonly called the fire tetrahedron. No fire can exist without all of these elements being in place.

 

Once ignited, a chain reaction must take place whereby fires can sustain their own heat by the further release of heat energy in the process of combustion and may propagate, provided there is a continuous supply of an oxidizer and fuel.

 

Fire can be extinguished by removing any one of the elements of the fire tetrahedron. Fire extinguishing by the application of water acts by removing heat from the fuel faster than combustion generates it. Application of carbon dioxide is intended primarily to starve the fire of oxygen. A forest fire may be fought by starting smaller fires in advance of the main blaze, to deprive it of fuel. Other gaseous fire suppression agents, such as halon or HFC-227, interfere with the chemical reaction itself.

So your reply implies that by the removal of heat, the fire will cease. How does fires exist in sub-freezing temperatures? Are the sub-freezing temperatures not cold enough to kill the fire?

 

Thankyou Bikeman for you superb response!!!

Edited by twinky64

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I know that fire needs the existence of heat, oxygen, and a fuel. To make fire, it is a chemical or molecular reaction.

 

I was thinking, does fire need heat to burn or is heat just a byproduct of fire. I understand fire can be produced from heat (super excited molecules containing a large amount of kinetic energy), however, can a fire exist in a freezer? I'm thinking, intuitively, that it will not go out.

 

I am majoring in Mechanical Engineering and as I saw the fire on the news last night in Porter Ranch, I'm thinking to myself how primitive our fire fighting tools and methods are. I asked a few classmates of mine, "would you take out a small bush fire with a spray bottle or water balloons?" So far I've gotten water balloons as an answer except one answered with a spray bottle. I argued that it will turn into vapor before it does anything to the fire. He countered argued saying that not only does water suffocate the fire, it "cools it down". Then I asked myself "does fire need heat to continue burning?"

 

Any thoughts?

Fire is the heat and light energy released during a chemical reaction, in particular a combustion reaction. Depending on the substances alight, and any impurities outside, the color of the flame and the fire's intensity might vary. Fire in its most common form can result in conflagration, and has the potential to cause physical damage through burning.

[edit] Chemical reaction

 

The fire tetrahedronFires start when a flammable and/or a combustible material with an adequate supply of oxygen or another oxidizer is subjected to enough heat and is able to sustain a chain reaction. This is commonly called the fire tetrahedron. No fire can exist without all of these elements being in place.

 

Once ignited, a chain reaction must take place whereby fires can sustain their own heat by the further release of heat energy in the process of combustion and may propagate, provided there is a continuous supply of an oxidizer and fuel.

 

Fire can be extinguished by removing any one of the elements of the fire tetrahedron. Fire extinguishing by the application of water acts by removing heat from the fuel faster than combustion generates it. Application of carbon dioxide is intended primarily to starve the fire of oxygen. A forest fire may be fought by starting smaller fires in advance of the main blaze, to deprive it of fuel. Other gaseous fire suppression agents, such as halon or HFC-227, interfere with the chemical reaction itself.

So your reply implies that by the removal of heat, the fire will cease. How does fires exist in sub-freezing temperatures? Are the sub-freezing temperatures not cold enough to kill the fire?

 

Thankyou Bikeman for you superb response!!!

Fire can exist at any temperature, but it spreads thru radiation of the heat generated.

Most of the preheating of fuels ahead of a fire is by radiation of heat from the fire. As the fire front gets closer, the amount of radiant heat received is increased.

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