For Fire Brigade Members Course Content PART 1 (Theory) Fire & its Components Fire Extinguishment Breathing Apparatus Portable Extinguishers
For Fire Brigade Members Course Content PART 2 (Practical Exercise) Breathing Apparatus Mobile Fire Fighting Equipment Hose Handling
R – escue E – xposure C – ontainment E – xtinguishment O – verhaul
For Fire Brigade Members <ul><li>Remember, Firemanship is .... </li></ul><ul><li>Knowledge of fire behavior and strategy. </li></ul><ul><li>Skill in handling tools and equipment. </li></ul><ul><li>Judgment of fire conditions. </li></ul><ul><li>Speed of attack and control </li></ul><ul><li>Teamwork at all times. </li></ul>
Oxidizing Agent (oxygen) Those materials that yield oxygen or other Oxidizing gases during the course of a chemical reaction. Fuel The material or substance being oxidized or Burned in the combustion process.
Heat Heat is the energy component of the fire tetrahedron. When heat comes into contact with a fuel, the energy support the combustion reaction.
HEAT Common Sources of Heat Chemical Energy Electrical Energy Mechanical Energy Nuclear Energy
Solid Fuels When heated to a certain temperature will produce combustible vapor. The actual position also affect the way it burns.
Liquid Fuels Flammable gases are generated by vaporization. Heat Paint Flammable Vapor
Gaseous Fuels The most dangerous of all fuel types because they are already in the natural state required for ignition.
PROPERTIES OF FLAMMABLE LIQUIDS Flammability Limits Oxygen Fuel Too Lean Flammable Range Too Rich
Flash Point The minimum temperature to which a liquid fuel gives off sufficient vapor that can be ignited momentarily by a flame. Fire Point The minimum temperature to which a liquid fuel gives off sufficient vapor to support continuous combustion.
Auto Ignition Temperature The minimum temperature at which a liquid fuel will ignite without the presence of a pilot flame or spark. Flammability Limit A flammable gas or vapor will only form in atmosphere if the flammable vapor and oxygen in air lies within certain limits. These limits are referred to us the lower and upper flammable or explosive limits.
SELF SUSTAINED CHEMICAL REACTION Combustion is a complex reaction that requires a fuel, an oxidizer, and heat energy to come together in a very specific way. Fire can only continue when enough heat is produced to cause the continued development of flammable vapors or gases.
Class A Fires Fires that involves ordinary combustible materials such as wood, cloth, paper, rubber, and many plastics. wood cloth paper rubber plastics
Class B Fires Fires that involves flammable and combustible liquids and gases. Gases Oil Motor spirit Paints
Class C Fires Fires involving energized electrical equipment
Oxygen exclusion (smothering) The oxygen content can be reduced by flooding an area with an inert gas, which displaces the oxygen and disrupts the combustion process. Heat Fuel O 2 Chemical Chain Reaction
Temperature Reduction (Quenching/Cooling) Reducing the temperature of the fuel to a point where it does not produce sufficient vapor to burn. Heat Fuel O 2 Chemical Chain Reaction
Fuel removal (Starvation) The fuel source may be removed by stopping the flow of liquid or gaseous fuel or by removing solid fuel in the path of fire. Heat Fuel O 2 Chemical Chain Reaction
Chemical flame inhibition (Breaking of chemical chain reaction) Extinguishing agents such as dry chemicals interrupt the combustion reaction and stop flaming. Heat Fuel O 2 Chemical Chain Reaction
The P.A.S.S. Method Pull the pin. Aim the hose or nozzle. Squeeze the lever. Sweep the agent.
WATER The direct effect is to cool down the unburned product, stop the evolution of vapor and starve the flame gradually until complete extinguishment. USAGE: Cooling/Quenching Displacing spills Handling clouds Making Foam Protecting personnel
DRY POWDER/CHEMICAL Finely divided powder acts with a chain-breaking reaction by inhibiting the oxidation process within the flame itself USAGE: <ul><ul><ul><li>Ordinary combustibles </li></ul></ul></ul><ul><ul><ul><li>Small spill fires </li></ul></ul></ul><ul><ul><ul><li>Jetting fuel fire </li></ul></ul></ul><ul><ul><ul><li>Fuel fire </li></ul></ul></ul><ul><ul><ul><li>Class C fires </li></ul></ul></ul>
CARBON DIOXIDE Brings the fuel/air mixture in the fire area below the lower flammable limit. The air and therefore, the oxygen concentration is reduced to such a level that the fire cannot sustain itself. General Characteristics of CO 2 Provides its own pressure for discharge Non-reactive to most substances Emerges as a gas which can penetrate all parts of fire area Non-conductor of electricity (Best for Class C fires)
FOAM EXTINGUISHMENT TRIANGLE <ul><li>Water content (heat) smothering and cooling the fuel </li></ul><ul><li>Blanket Effect (fuel) forms a floating blanket on the liquid surface </li></ul><ul><li>Bubbles Formation averts formation of combustible mixture of vapor and air </li></ul>
TRANSMISSION OF HEAT <ul><ul><ul><ul><ul><li>CONDUCTION </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>CONVECTION </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>RADIATION </li></ul></ul></ul></ul></ul>
TRANSMISSION OF HEAT Conduction Conduction is the point-to-point transmission of heat energy. HEAT
TRANSMISSION OF HEAT Convection Convection is the transfer of heat energy by the movement of heated fluids. HEAT
TRANSMISSION OF HEAT Radiation Radiation is the transmission of heat energy through electromagnetic wave.
RATE OF OXIDATION Oxidation Rusting Self-Heating Flammable Liquid Fire Explosion Very Slow (months) Hours Seconds Rapid Combustion maybe very slow or very rapid.
THE COMBUSTION PROCESS Heat Source Fuel (wood) Vapor produced Vapor broken down Air and fuel mix COMBUSTION Light Heat
HEAT AND TEMPERATURE Heat energy in transit An indicator of heat and is a measure of the warmth or coldness of an object based on standard arbitrary unit. HEAT Temperature
FIRE DEVELOPMENT Atmospheric condition flammable vapor coming out from the fuel is invisible. Incipient Stage 10% of the flammable vapor from the fuel is visible. Smoldering Stage flammable vapors are ignited and self propagating. Flaming Stage Generates sufficient heat to warm the air immediately around the fire. Heat Stage
FIRE DEVELOPMENT Confined Space Incipient Stage Full-blown Stage Burn-out Phase Flashover Ignition Growth Fully Developed Fire Decay Time
FIRE DEVELOPMENT Confined Space Ignition – describes the period when the four elements of fire tetrahedron come together and combustion begins. Growth – fire plume begins to form above the burning fuel. Flashover – transition between the growth and fully developed fire. Fully developed – all the combustible materials in the confined space are involved in fire. Decay – the rate of heat releases begins to decline.
Example: for 4 liter/300 bar cylinder Total air capacity = Cylinder capacity x Cylinder pressure = 4 x 300 = 1200 liters of air Total duration of = Total air capacity / Average consumption cylinder = 1200 / 40 = 30 mins Working Duration = Total duration - Safety factor = 30 mins - 10 mins = 20 mins