The four methods of fire fighting are isolation, suffocation, cooling and chemical suppression.

The four methods of fire fighting are isolation, suffocation, cooling and chemical suppression.

First, the isolation method

Isolation method is to separate the combustible materials around the fire source so that they do not burn. Isolation method is suitable for extinguishing fires caused by liquids or gases, such as oil, natural gas and liquefied gas.

The most common isolation method is to close the valve of the pipeline conveying flammable liquid or flammable gas and cut off the supply of flammable substances. At the same time, open the valve leading to the safe area and transfer the combustible materials.

Second, the suffocation method

Asphyxiation is to reduce the oxygen in the air with non-combustible gas or other fire extinguishing agents, so that it is not enough to maintain combustion. Asphyxiation method is suitable for extinguishing fires with flame burning, such as oil, electricity and wood.

The most commonly used extinguishing agents for asphyxiating gases are nonflammable gases, such as carbon dioxide, nitrogen and steam. These extinguishing agents can be poured into the fire site through fire extinguishers and fire extinguishing systems to reduce the oxygen concentration in the space. Generally speaking, when the oxygen concentration in the air is lower than 15%, combustion cannot be maintained.

Third, the cooling method

Cooling method is to reduce the temperature of combustion products with water or other fire extinguishing agents, so that they will not burn any more. Cooling method is suitable for extinguishing fires caused by solid substances, such as wood, paper and cloth.

The following points should be paid attention to in the cooling method: Do not use water to extinguish oil, electricity, metal and other fires, otherwise it will explode or get an electric shock. Do not use water to extinguish high-temperature objects or substances that generate heat when exposed to water, or steam will explode. Do not use water to put out deep fires or fires such as precision instruments, precious cultural relics and archives, otherwise it will cause water accumulation or damage.

Fourthly, chemical inhibition method.

Inhibition method is to use chemical fire extinguishing agent to interfere with the chemical reaction of combustion and stop it. Suppression method is suitable for extinguishing fires with flame burning, such as oil, electricity and metal powder.

The most commonly used extinguishing agents for suppression method are chemical extinguishing agents containing fluorine and bromine, such as 12 1 1, heptafluoropropane, etc. These extinguishing agents can be sprayed to the flame through fire extinguishers, fire extinguishing systems and other means, so that the extinguishing agents can participate in the combustion reaction and interrupt the combustion chain reaction, thus achieving the purpose of extinguishing the fire.

Matters needing attention when extinguishing fire:

1. Choose fire extinguishing agent correctly and give full play to its effectiveness.

Commonly used fire extinguishing agents include water, steam, carbon dioxide, dry powder and foam. Because there are many kinds of fire extinguishing agents, their effectiveness is not the same, so when putting out a fire, we must choose a fire extinguishing agent with high cooling and extinguishing efficiency according to the properties of burning substances, the characteristics of equipment and facilities, the location (height) of the fire source and the size of the fire.

2, pay attention to protect the key parts.

For example, when there are a large number of flammable, explosive or toxic chemicals in a certain area, this part should be taken as the key protection object. While implementing cooling protection, organize efforts to eliminate the fire sources around it as soon as possible to prevent the disaster from expanding.

3. Prevent re-ignition and re-explosion.

After the fire is extinguished, a necessary number of fire fighting forces should be left to continue to cool the equipment, facilities and buildings in the burning area and eliminate the fire source; At the same time, the leaked dangerous chemicals should be treated in time, especially the residual combustible gas or steam in the space should be diluted with steam or spray water as much as possible to prevent re-ignition and re-explosion.