At 8:30 on August 20 or so, Shandong Yantai Longkou City, a bus was set on fire resulting in one dead and 19 injured. August 21 5:00 pm, Xinjiang Hami railway station waiting room new construction site accidentally ignited wall insulation, causing a fire, but fortunately no casualties.
Fire triangle
The event of fire, although complex, but it must have some basic combustion conditions, that is, there must be combustible (fuel), Combustion and ignition source, which is called the "fire triangle." These three conditions are indispensable, and only when the interaction of three factors, a fire can occur.
Combustibles (ie fuel) is with oxygen in the air from combustion or other oxidant chemical reactions may be a gas, liquid or solid. Fuel mostly of carbon and hydrogen compounds (e.g., natural gas, gasoline, wood, paper, cloth, plastic, etc.), but some metals (such as magnesium, aluminum, calcium) under certain conditions can burn. Combustion is to help and support the burning of combustible material, which is matter oxidation reaction, also known as the oxidizing agent can react with combustible materials. Typically, fire accelerant mainly oxygen in the air. Ignition source is caused by fuel combustion reaction occurs with accelerant energy sources, the most common is the heat. Heat seems simple, but in fact its origins are complex, chemical, electrical, mechanical energy and so can be converted into heat. So fire prevention, fire fighting, to fully consider these possible sources of ignition.
Smoldering
Smoldering is no slow-burning flame. This happens only solid fuel combustion, liquid and gaseous fuels do not burn the perineum. Smoldering temperature rises, sometimes may produce smoke, but the reaction is not severe, there is no bright flame, it is not easy to arouse people's vigilance. Many materials, such as paper, sawdust, bran, fiber, etc. accumulate in high temperature environment, are likely to occur smoldering. When heated, these materials decompose, like charcoal that will form a porous structure, the heat stored in the interior, maintaining high temperature, so that the oxidation reaction can be carried out continuously.
Hot smoldering produced the material can be combustible substances evaporate. When the space near the smoldering combustible material gas reaches a certain concentration, it may become flaming combustion. Burning cigarette is smoldering, daily life, smoldering cigarette often causes carpet, wood chips smoldering and then causing a fire.
Flaming combustion after the flame goes out, sometimes will still continue to smolder. Like wood combustion smoldering charcoal will continue the same. Therefore, we must pay attention to prevent secondary fires smoldering produced after the fire is extinguished.
How fire?
In case of fire, how quickly and effectively put it out of it? Seen from the foregoing description, the three elements are burning fuel (fuel), Combustion (oxygen) and ignition sources are indispensable. We can start with these three elements, as long as the cut off any one element, can achieve the purpose of extinguishing. Several basic fire fighting method comprising: cooling method, asphyxiation, isolation and chemical inhibition method.
Cooling method is to fire extinguishing agent is sprayed directly onto the combustion, the combustion temperature is reduced to below the ignition point, combustion is stopped. This method is also suitable for cooling unburned objects, such as building components, equipment, etc. to prevent them from heat radiation and fire or explosion occurred. In fact, cooling method is the elimination of the three elements of the ignition source. Is a commonly used cooling water fire extinguishing agent. Specific heat of water is relatively large, it can absorb heat. More importantly, a large heat of vaporization of water, to 1 kg of water vapor into water vapor, it takes about 2260 kJ of heat. Thus, when the water is vaporized in the fire, it will absorb a lot of heat produced by combustion, play a role in cooling down. On the other hand, the water is vaporized, the volume will increase a thousand times, but also play the dilution air (oxygen) role.
Asphyxiation by reducing the oxygen concentration in the combustion products around the fire to achieve the purpose, such as covering the burning material with a wet towel, sand and other fire-retardant materials, or can not use combustion gases such as carbon dioxide, nitrogen flame and air isolation. This method is to remove the three elements of the accelerant. Suffocation method is suitable for fighting a closed room and production equipment, fire equipment within the container.
Isolation method for the three elements of the combustibles. Remove or isolate the source of fire at or around combustibles, combustion stops. Isolation method is suitable for fighting all kinds of solid, liquid and gas fires.
Chemical suppression method is actually cut off the reaction between fuel and combustion improver. Dry and combustible substances Halon fire extinguishing agents and other alternative is the use of this method, this type of fire extinguishing agent and substances produced by combustion of free radicals combine to form a stable no further occurrence. That is, by chemical action, undermining the chain reaction of combustion, the combustion is terminated. Chemical fire suppression method is suitable for most occasions.
When the bus on fire how should I do?
Especially when the vehicle is on fire the fire spread rapidly, often within seconds swept the entire vehicle. Fire-fighting equipment installed in the car for passengers who provide the first protection. Currently, most of the public transportation vehicle is equipped with a dry chemical fire extinguishers and other fire safety equipment hammer. Fire extinguishers are usually placed near the door and behind the driver, the general safety hammer hanging near the window. Public transportation vehicle is also equipped with escape signs indicating the location of each safety emergency switch and outlet.
One reason is that the bus caught fire inside the engine oil leaks. In driving the process If you smell fuel smell, and is accompanied by significant pills only to discover, you can determine possible engine compartment fire. It should immediately turn off the power, stop the engine. Note that this time do not open the hood out the fire, open the front cover because the influx of large amounts of oxygen, may lead to the rapid expansion of the fire. The correct approach is to pull the front cover a slits, with a fire extinguisher at the injection point.
If there is a strong pungent odor and smoke inside, indicating a combustion phenomenon occurs, then the driver should immediately stop, look carefully the source of fire, water or mops, towels, etc. extinguish the fire. If the car has just appeared fire, will have to quickly put out with a fire extinguisher can also be used to carry passengers tea and mineral water to the fire. Passengers do not panic, ordered to evacuate.
When the bus fire, passengers escape quickly select the correct method is an important aspect of reducing the casualty loss. The driver should immediately open the door to evacuate the passengers, passengers can also flip through the door at the top of a red panic button will open the door. Case of emergency, in addition to the passenger door to escape from the place, you can also use the "safety hammer" smashed the side windows to escape. In general, the middle glass windows used in the most strong, weak corners and edges, so when the windows broken window to escape violent percussion corners and edges, and then the piece of glass out of a window. For some air-conditioned car, passengers can also rotate the red switch on the top of the car roof, skylights and hand stretched as exits.
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