Chapter 5: Fire Behavior Flashcards
I’m the British System (Which is what we use) distance is measured in?
Liquid volume is measured in?
Temperature is measured in?
Pressure is measured in?
- Feet & Inches
- Gallons
- Degrees Fahrenheit
- Pounds per square inch
I’m the Metric System, distance is measured in?
Liquid is measured in?
Temperature is measured in?
Pressure is measured in?
- Meters
- Liters
- Degrees Celsius
- Pascals or Kilopascals
What is fire?
A rapid chemical process that produces heat and usually light. Fire requires fuel that is in the form of combustible gas or vapors, in order for the chemical process of combustion to occur. Materials that remain in a solid or liquid state will not burn while in that state. As these materials are heated, they produce a gas or vapor that is ultimately ignited. Solid fuels such as wood, liquid fuels such as gasoline and gaseous fuels such as propane will all burn after they change into a vapor.
Subtitle: States of Matter
Matter is made up of atoms and molecules. What are the three stages in which matter exist?
Solid: A material that has three dimensions and is firm in substance, such as wood.
Liquid: A fluid (such as water) that has no independent shape, but has a definite volume and does not expand indefinitely and that is only slightly compressible.
Gas: The physical state of a substance that has no shape or volume of its own and will expand to take the shape and volume of the container or enclosure it occupies (like propane).
Subtitle: Fuel
What is Fuel?
Materials that store energy. Think of the vast amount of heat that is released during a fire. The energy released in the form of heat and light has been stored in the fuel before it is burned. The release of the energy in a gallon of gasoline, for example, can move a car many miles down the road. Many common household materials such as computers, TV’s, furniture and carpets, consist of fuels that will burn under the right conditions.
Subtitle: Types of Energy
There are five types of energies, what are they?
- Chemical Energy
- Mechanical Energy
- Electrical Energy
- Light Energy
- Nuclear Energy
What is Chemical Energy?
Energy created by a chemical reaction. Some chemical reactions produce or give off heat (Exothermic) and others absorb heat (Endothermic). The combustion process (Fire) is an example of an exothermic reaction, because it releases heat energy. Ice cubes melting (absorbing heat) is an example of an endothermic reaction. Most chemical reactions occur because bonds are established between two substances or bonds are broken as two substances are chemically separated. Heat is produced whenever oxygen combines with a combustible material. If the reaction occurs slowly in a well ventilated area, the heat is released harmlessly into the air. If the reaction occurs rapidly or within an enclosed space, the mixture can be heated to its Ignition Temperature and can begin to burn.
What is Exothermic?
What is Endothermic?
Chemical reactions that result in the release of energy in the form of heat. It gives off heat (Such a Fire).
Chemical reactions that absorbs heat or require heat to be added (Such as Ice).
Ignition Temperature
The minimal temperature at which a fuel, when heated, will ignite in the presence of air and continue to burn. Fire is an example of energy being released as a result of a chemical reaction. An example of this occurs when a bundle of rags soaked with linseed oil releases enough heat through oxidation causing the rags to ignite spontaneously.
Mechanical Energy
Mechanical energy is converted to heat when two materials rub against each other and create friction. Heat is also produced when mechanical energy is used to compress air in a compressor.
Electrical Energy
Heat that is produced by electricity. Electrical energy is converted to heat energy in several ways. For example, electricity produces heat when it flows through a wire or any other conductive material. The greater the flow of electricity and the greater the resistance of material, the greater the amount of heat produced. Examples of electrical energies that can produce enough heat to start a fire is electric heating elements, overloaded wires, batteries etc.
Light Energy
Light energy is produced by electromagnetic waves packaged in discrete bundles called photons. This energy travels as thermal radiation, a form of heat. When the light energy is hot enough, it can sometimes be seen in the form of visible light. One example of light energy is the radiant energy we receive from the sun. We think of candles, fires, light bulbs and lasers as forms of light energy. Recognize that while these produce light, they also produce heat. They transfer most of their heat via convection or radiation. If they are touching something, they also transfer heat using conduction. If light energy is of a frequency that we cannot see, the energy may be felt as heat but not seen as visible light.
Nuclear Energy
Created by splitting the nucleus of an atom into two smaller nuclei (nuclear fission) or by combining two small nuclei into one large nucleus (fission). Nuclear reactions release large amounts of energy in the form of heat. These reactions can be controlled as in a nuclear power plant or controlled as in an atomic bomb explosion. Nuclear energy is stored in radioactive materials and converted to electricity by nuclear power generating stations.
Subtitle: Conservation of Energy
What does the law of conservation of energy states?
States that energy cannot be created or destroyed by ordinary means. Energy can however, be converted from one form to another. Think of an automobile, chemical energy in the gasoline is converted to mechanical energy when the car moved down the road. When you press the breaks, the mechanical energy is converted into heat energy by the friction between the wheel rotators and break pads.
Subtitle: Conditions needed for Fire
What are the three basic elements needed for combustion?
Added to these three basic elements to create a Fire tetrahedron is called a?
- Fuel: First, combustible fuel has to be present.
- Oxygen: Second, oxygen must be available in sufficient quantities.
- Heat: Third, a source of ignition (heat) must be present.
These three components together creates a fire triangle. A fourth factor, which is a chemical chain reaction, must result from the first three roe to produce and maintain a self sustaining fire. When a fire triangle United with a chemical reaction, it is called a Fire Tetrahedron. If you remove any of the three key elements of a fire, it will go out.
