Basic Principles of Fire Extinguishment
The basic methods of fire extinguishment are the following:
1. Smothering it (excluding air - oxygen).
2. Removing the combustible material.
3. Cooling (taking the temperature of combustible material below the
ignition point).
Speed of combustion is an important matter when considering the controlling of a fire. This is dependent on the factors:
1. Calorific value of the combustible material (amount of heat given off during burning).
2. Heat - conductivity of the combustible material (its ability to conduct heat away from the burning parts and thus prevent other surrounding things from ignition). It should be noted that chopped material will burn more readily than a solid block of the same substance. For the same reason liquid in the form of a spray burns more readily than in bulk.
Combustible solids can be divided into three general classes depending upon their "specific surface" (the ratio of surface area to weight of material). These classes are:
1.Tinder - material which can be ignited with an ordinary match.
2. Kindling - material which cannot be ignited with a match but will be ignited with sufficient tinder.
3. Bulk fuel - material which neither a match nor tinder will light, but which needs the extra of burning kindling.
UNIT 6
Theme: Fire Prevention and Fire Safety
TEXT 1
Fire Prevention
Fire prevention is a term for many safety measures used to keep harmful fires from starting. Each year, about 2 1/2 million fires are reported in the United States. The fires cause about 9000 deaths and billion of dollars worth of damage. In Canada, about 65000 fires cause over 600 deaths annually.
In Russia about 260,000 fires are reported each year. These fires cause about 15,000 deaths and injuries annually.
More than a fourth of all people killed or injured by fire are children.
Three main methods are used to prevent fires:
1. Laws and regulations
2. Inspection of buildings and other property
3. Public education about fire safety
To help preventing fires and reducing fire losses local fire departments inspect public buildings. They also teach people about fire safety.
Most states and cities have codes and standards that require certain types of fire retardant materials and electric wiring to be used in buildings. Fire departments and other public agencies inspect public buildings for fire hazards and recommend corrective action.
Most cities have a fire safety code that applies to such buildings as theatres, department stores, schools, and hospitals. These codes specify that the buildings should not be made of materials that burn easily. The codes also require portable fire extinguishers, a certain number of exits, and other fire safety features in public buildings. Many fire safety codes require large buildings to have built-in sprinkler systems and special water lines to which fire hoses can be attached. Many fire safety codes also require high-rise structures to have fire alarm systems.
The officials check the operating condition of the fire protection systems. They note the number and location of exits and fire extinguishers. Fire department inspectors may also review plans for a new building to make sure it meets the safety codes.
Education is a vital part of fire prevention programs because people cause and could prevent almost all fires. Fire departments and school teach children and adults about fire hazards and work to reduce fires throughout the community.
Many fire departments work with other local agencies to teach people how to prevent fires and what to do during a fire.
Most of the deaths caused by fires occur in private homes. Many home fires are caused by leaving the kitchen when food is cooking, disposing of cigarettes improperly, misusing portable heating equipment, and placing flammable or combustible items too close to heat sources. To make your home safer, check the heating systems and the cooking equipment, look for unsafe practices, such as overloading electric outlets or running electric cords under a rug.
It is important to know what to do if a fire breaks out. To leave the home safely and quickly in case of fire, families are advised to make escape plans and to practise fire drills.
Fire departments also recommend that people have portable fire extinguishers in their homes. A person must call the fire department before trying to extinguish a fire. It is also important to use the right kind of extinguisher for the type of fire involved.
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