After the fire occurs and the development of fire and smoke spread very rapidly, the smoke is very harmful to people, for the fire in the general civil housing and public buildings, time is the most precious and critical factor, encounter a fire to escape quickly, firmly grasp the best time for fire escape, must not escape blindly.
What is the best time to go? The answer to the question varies from fire to fire, and it is relatively safe to escape quickly within a minute of a fire.
Therefore, the escape of the "golden minute" fire scene still needs to be grasped by yourself. We must detect the fire as soon as possible, extinguish, escape and evacuate personnel as soon as possible, call the police as soon as possible, and try to avoid and reduce personal injury.
Fire trivia
► Necessary conditions for fire, that is, the so-called fire triangle or fire tetrahedron: combustibles (there must be combustible substances), ignition source (combustibles must reach the ignition temperature under the action of the ignition source), accelerant (usually oxygen), as for the fire tetrahedron is based on the above three factors, plus chemical chain reaction, that is, the combustible material undergoes a series of chain reactions, and then the fire occurs out of control.
►Deflagration: refers to the phenomenon of sudden and comprehensive combustion of fire in the building, that is, when the combustible gas and gas that are not fully burned in each room of the room formed by the indoor fire reach a certain concentration, the deflagration is formed, which leads to the combustibles in other rooms in the room that are not in contact with the fire are also ignited and burned, this phenomenon is called deflagration.
► Conditions under which deflagration occurs:
(1) The ventilation conditions are poor, and the combustible gas formed by combustion accumulates in the room in large quantities.
(2) These combustible gases diffuse around or on the surface of other combustibles.
(3) These combustible gases reach a certain concentration and deflagration occurs.
Laboratory room structure
► A room surrounded by 10mm steel plates without fire protection measures
►Temperature probes on both sides of the room (real-time monitoring of the temperature in the room)
► There are waste paper baskets, curtains, sofas and other objects in the room
► There is a piece of ordinary glass with a thickness of 4mm behind the curtain
Figure 1: Laboratory structure
Figure 2: Animation of the laboratory structure
Experimental process
00'12"
The staff lights the wastebasket, the paper in the wastebasket catches fire, and the experiment begins
00'55"
The fire ignites the curtain (a red flag), and the fire burns vertically along the curtain, greatly accelerating the overall indoor temperature rise rate, further exacerbating the indoor heat accumulation
Figure 3: Fire ignites the curtains
01'10"
When the indoor temperature reaches more than 40°C, this is the last chance to save yourself
01'30"
If the best time to extinguish the fire is missed, the individual cannot extinguish the fire and must call the fire alarm immediately
01'46"
The heat continues to accumulate, and the indoor temperature reaches more than 60°C
02'10"
4mm ordinary glass is not heat-resistant, as the curtain continues to burn, the glass window bursts, oxygen enters (to achieve the primary condition for deflagration: sufficient oxygen supply) The indoor temperature rises sharply, and it is about to reach the critical point of deflagration
Figure 4: Glass windows burst
02'20"
The temperature breaks through the critical point, the combustion enters a transient change, and the explosion occurs, and the fire in the whole room enters the stage of full occurrence
Figure 5: Ignition occurs
Through instrument monitoring, the indoor temperature reached 780 °C after the deflagration, oxygen was consumed in large quantities, and the carbon monoxide content rose sharply. In the absence of any flames, the surface of the interior begins to vaporize and burn rapidly, and the chance of escape is almost zero.
Figure 6: Spontaneous combustion of the vaporization of the object
Through experiments, we can see that in just over two minutes, the deflagration will occur. Before a fire breaks out, that is, after a fire breaks out, we must take steps to extinguish the fire (using a fire extinguisher, hydrant or other "fire extinguisher") or escape, and we must call the fire alarm, the property control room, and our neighbors to evacuate.
Fire fighting, the world's problem!
Firefighters "fighting fires" can only be fire rescue
The last line of defense
And not the first line of defense
Before the fire
Everyone is a fire preventer
They should all be the "fire prevention people"!
People always think
Fire, that's a few percent probability
It has nothing to do with yourself
As everyone knows
It is precisely because of the carelessness and luck in the heart
The hidden danger of fire was laid
That's the way to put an end to the chance of fire
Slip away in an instant!
Check in the bud:
"Firefighting" actually started before the open flames appeared!