Fire Project - Assignment Example

Question A2 The total energy in the room is derived from the propane, polystyrene, water and butter components. To calculate the total energy we break the energy in the following compounds;Water………………….. 4.18Propane……………………………….2.23Polystyrene………………………….1.76Total 8.17Kj/Kg/K2. The heat capacity of wood is 2.0 Kj/Kg/K. Heat of combustion for a hydrocarbon where wood belongs is 46400kj/Kg. The amount of wood equivalent to fuel would be 46400kj/kj/2kj/kg=23200.3. The heat of combustion of kerosene is 43200 Kj/kg.

The heat capacity of elements under kerosene group is 2.37kj/kg. The amount of kerosene equivalent to fuel would be =43200/2.3718227.8kg4. The time is calculated using the formula; t=V/A/Reg Rate, t is the time taken in seconds, V is volume of kerosene, A is surface are of spread and Reg rate is regression rate of kerosene. The regression rate of kerosene is given by; =0.039/820=0.000048m/sSurface area==3.142*25=78.6m2Circumference ==3.142*10=31.42mVolume=31.42*78.

6=2468m3V/A=31.4mTime=31.4/0.000048=654166 secondsQuestion B21. The volume of the pool of kerosene is 2468m3. Mass of water, m==42/4.180*293.5+2260=0.01kgGallons of water =0.01kgx (2.21/kg+9.82/2468 =221 gallons of water2. In fire fighting, use of water alone has limitations. Water cannot cool and penetrate certain fuels and fire because of its high surface tension. This high surface tension causes water to form into droplets, and consequently, the majority of the droplets roll off of fuels, impeding waters heat absorption potential.

This problem is solved by using foam with water. The foam with water is treated water that reduces surface tension and this allows more surface area of water droplets applied to contact the fire. This necessitates increased heat transfer through conduction. Foam with water belongs to a hydrocarbon surfactant and becomes biodegradable when mixed with water. The hydrocarbon surfactant has affinity for and this causes the water to penetrate upto the fire hence the increasing fire extinguishes. A thick blanket is formed by foam in water which suppresses the fire cutting it off the oxygen (Jeff & Routley, 1996).

Foam bubbles adhering to fuels will cause the foam solution to remain on it where it will penetrate or evaporate, until it the fire is extinguished. The benefits of using foam to fight fire include increased firefighter safety, increased fire operation efficiency, and reduced properly damage. 3. Foam is made from Perfluorooctane sulfonate which is highly a pollutant if it escapes into the environment. Foam that diffuses into water bodies can cause death of acquatic animals. Organisms like birds and fish, mistake this compound for food and ends up dying.

When these animals die the ecosystem is polluted. Plastic components from foam is a vector for pollutants that bio-accumulate in the food chain. When ingested by fish, toxic coated plastics can pollute the human food chain.4. The dry ice has limitation in fire fighting. The carbon dioxide which is the dry ice offers little security for fire fighting since it is very light and can be blown away by wind. The gas requires large containers for storage which is cumbersome to transport during fire fighting and the containers can easily explode with the gas.

When the gas is being oozed off from the container it produces a sound which can be scary, cause panic and can cause environmental pollution through sound. Lastly, the gas looks like dense white cloud which could impair visibility during fire fighting.5. Other extinguishing fire methods include taking advantage of the weather. The rate at which fire spreads depends on the conditions of the prevailing weather conditions like wind speed, temperature and relative humidity. Extreme weather conditions like can also play a role in the strength and number of wildfires in an area.

Accurate and timely weather information is vital to the planning and execution of strategies for suppressing wildfires. Another strategy to fught fire is also to create a fire line which contains fire immediately, preventing spreading and future damage. A controlled burn area around the perimeter of a forest fire also helps fight the fire risk. A controlled burn will allow a cut off the fuel source of the larger fire by already burning off the dry plants, thus stopping the spread of the fire.

Taking advantage of natural barriers also helps fight fires. Areas like rivers, lakes, roads, swamps and rocky areas can be a natural ending spot for a fire. ReferencesJeff, S and Routley, J G 1996. Class A Foam for Structural Firefighting. U.S. Fire Administration/Technical Report Series, Homeland Security.[web.17th Nov.2014]