Recently, we had a Norco High School science class stop by our headquarters in California for a tour and to check out some of our technology. The class got a demonstration of both outdoor and industrial fires. We demonstrated our Fuel Spill Prop and Propane Cylinder Prop for the students. Heat transfer and the science behind fire were among the questions the kids were burning to ask (lame pun intended), so we decided to devote some time to further answer their questions.
Science of Fire
Fire is a chemical reaction between oxygen and fuel – wood, lighter fluid, gasoline, etc. –when the fuel is heated to ignition temperature. When heated enough, the fuel – if it is not already a gas – releases gases and allows combustion to take place. Gases are made up of groups of atoms. When they are hot enough, they break apart to join with oxygen. Those atoms then form water molecules and carbon dioxide molecules. A chain reaction must take place in order for the fire to sustain itself and keep burning. An exact mix of fuel and oxygen need to be present for complete combustion. Complete combustion occurs when there is enough oxygen to combine with all the gas molecules. The flame produced from complete combustion is normally blue and it produces no smoke.
Below is the chemical equation of a complete combustion with methane gas as the fuel. The equation illustrates how the methane gas, oxygen gas, and heat produce carbon dioxide gas, water vapor, and heat.
CH4 (g) + 2O2 (g) + heat ⇒ CO2 (g) + 2H2O (g) + heat
Methane + Oxygen + heat ⇒ Carbon Dioxide + Water + heat
Incomplete combustion occurs when there is not enough oxygen present during the chemical reaction. Incomplete combustion normally has a yellow or orange flame and smoke is emitted. This type of combustion also produces carbon and carbon monoxide along with water and carbon dioxide.
Heat transfers from a higher temperature object to a lower temperature object. The transfer takes place until both objects have reached thermal equilibrium, which means they both are the same temperature. There are three main types of heat transfer: conduction, convection, and radiation. Conduction occurs between objects that are directly touching. The particles in the hotter object collide with those of the colder object. This kinetic energy is then transferred to the colder object until they reach thermal equilibrium. Once thermal equilibrium is reached the particles still collide, but they move at the same rate and sustain consistent kinetic energy. Convection happens through mass motion of a fluid. When the fluid is heated it moves away from the source of the heat and carries that energy with it. An example of this would be air in a heated house. The hot air becomes less dense and rises away from the heat source, carrying the heat with it. The colder air sinks and the cycle continues over and over again. Heat transfer through radiation happens with electromagnetic waves. Heat radiates from a central object to the area surrounding it. The higher the temperature of an object, the more it radiates heat. Thermal imaging shows the electromagnetic waves as they radiate off an object, thus creating the image.
It was a pleasure to have the students from Norco High School check out our headquarters and learn about fire safety. We were happy to give them a chance to incorporate elements from their science class into what we do at Fireblast Global. Below are some great candid moment with the class and some of the demonstrations we gave. Overall, the students had a great time and we hope they leaned a lot.
Pictured above: Fireblast Global CEO, Rick Egelin, talking with students from Norco High School
Pictured above: Students watching a demonstration of our Fuel Spill Fire Prop
Pictured above: Student watching a demonstration of our Propane Cylinder Prop