What are the four main methods of fire extinguishing principle?

The three elements of combustion: combustibles, accelerants, and the ignition point is reached.

Removal of combustibles: Cutting down burning trees around a forest fire.

Remove the accelerant: Cover the pan when the pan** is greasy.

Lower the temperature: Extinguish the fire with water.

The four basic principles of fire extinguishing are cooling fire extinguishing, isolation fire extinguishing, suffocation fire extinguishing, and chemical inhibition fire extinguishing. 1. Cooling fire extinguishing: for combustible solids, cool them below the ignition point; In the case of flammable liquids, the combustion reaction may be aborted by cooling them below the flash point.

2. Isolation and fire extinguishing: the foam is covered on the surface of the burning liquid or solid, which separates the combustible material from the air while playing a cooling role, so as to extinguish the fire. <

The four basic principles of fire extinguishing are cooling fire extinguishing, isolation fire extinguishing, suffocation fire extinguishing, and chemical inhibition fire extinguishing.

1. Cooling fire extinguishing: for combustible solids, cool them below the ignition point; In the case of flammable liquids, the combustion reaction may be aborted by cooling them below the flash point.

2. Isolation and fire extinguishing: the foam is covered on the surface of the burning liquid or solid, which separates the combustible material from the air while playing a cooling role, so as to extinguish the fire.

3. Suffocation fire extinguishing: In the fire place, the oxygen concentration of the space can be reduced by pouring non-combustible gas, such as carbon dioxide, nitrogen, steam (water spray), etc., so as to achieve suffocation and fire extinguishing.

4. Chemical inhibition of fire extinguishing: Since flame combustion is carried out by chain reaction, if the production of free radicals can be effectively inhibited or the concentration of free radicals in the flame can be reduced, the combustion can be stopped.

1. The first basic principle and method of fire extinguishing, isolation method to extinguish fire. The basic principle of isolation fire extinguishing is to separate or separate the burning object from the combustible substance. If there is no support, the combustion cannot be sustained, and then it gradually stops.

2. The second basic principle and method of fire extinguishing, the continuous combustion of the suffocation fire extinguishing method requires oxygen to support combustion and suffocation, and the fire extinguishing method is to prevent oxygen and air from entering the combustion area, isolate the burning substance from oxygen, and then make the combustion unable to continue, and gradually extinguish the fire.

3. The third basic principle and method of fire extinguishing, cooling fire extinguishing method is to spray the fire extinguishing agent lower than the flame temperature directly on the combustible material, which can reduce the temperature of the burning substance below the ignition point, so that the combustion stops, and the most common is to extinguish the fire with water.

4. The fourth basic principle and method of fire extinguishing, inhibiting fire extinguishing method. It is that the fire extinguishing agent is in close contact with combustible substances to inhibit the generation of combustible factors and stop the combustion reaction, the most common is to use a dry powder fire extinguisher to extinguish the fire.

The combustion of a substance must meet three necessary conditions at the same time, namely combustibles, combustibles and ignition sources. According to these basic conditions, all fire extinguishing measures are aimed at destroying the combustion conditions that have been formed, or terminating the chain reaction of combustion to extinguish the fire and control the fire within a certain range, so as to minimize the fire loss. This is the basic principle of fire extinguishing.

Cooling method: such as extinguishing the fire of general solid matter with water, absorbing a large amount of heat through water, so that the temperature of the burning material is rapidly reduced, and finally the combustion is terminated.

Asphyxiation method: such as using carbon dioxide, nitrogen, water vapor, etc. to reduce oxygen concentration, so that combustion can not be sustained.

Isolation method: such as using foam fire extinguishing agent to extinguish the fire, through the resulting foam covering the surface of the combustible body, while cooling the effect, the combustible material is isolated from the flame and air to achieve the purpose of fire extinguishing.

Chemical inhibition method: such as using dry powder fire extinguishing agent to destroy the chain reaction of combustion through chemical action and stop combustion.

2 Basic measures to extinguish fires.

Extinguishing Class A fires: Generally, water cooling can be used, but for water-resistant substances, such as cloth, paper, etc., the loss caused by water stains should be minimized. Precious books and archives should be extinguished with carbon dioxide, halide alkanes, and dry powder fire extinguishing agents.

Extinguishing Class B fires: First of all, the combustible liquid should be cut off, and at the same time, the combustible liquid in the container in the combustion zone should be discharged to a safe area, and the container wall of the combustible liquid in the combustion zone should be cooled with water to slow down the evaporation rate; Use a large dose of foam fire extinguishing agent and dry powder fire extinguishing agent in time to extinguish the liquid fire.

Extinguishing Class C fires: First of all, the combustible gas valve should be closed to prevent the occurrence of combustible gas, and then dry powder, halide alkyl and carbon dioxide fire extinguishers should be used to extinguish the fire.

Extinguishing Class D fires: For example, magnesium and aluminum burn at very high temperatures, and water and other ordinary fire extinguishing agents are ineffective. Sodium and potassium fires should not be extinguished with water, as water reacts with sodium and potassium to release a large amount of heat and hydrogen, which will promote the violent development of fires. Special extinguishing agents are applied, such as dry sand, etc.

Extinguishing live fires: It is good to use "1211" or dry powder fire extinguishers and carbon dioxide fire extinguishers, because the fire extinguishing agents of these three fire extinguishers have good insulation performance and will not cause electric shock accidents.

There are four basic principles of fire suppression: cooling, asphyxiation, isolation, and chemical inhibition.

From the basic conditions that must be met for combustion, it can be known that fire extinguishing is the process of destroying the combustion conditions and stopping the combustion reaction. Its basic principles can be summarized in the following four aspects:

1) Cooling and fire extinguishing: For general combustibles, one of the conditions for continuous combustion is that they reach their respective ignition temperature under the action of flame or heat. Therefore, in the case of general combustible fires, the combustion reaction is stopped by cooling the combustible materials below their ignition point or flash point.

This principle is used to extinguish ordinary fires with water.

2) Suffocation fire extinguishing: The combustion of all kinds of combustibles must be carried out above its minimum oxygen concentration, otherwise the combustion cannot be continued. Therefore, by reducing the oxygen concentration around the combustibles, it can play a role in extinguishing the fire.

Carbon dioxide, nitrogen, water vapor, etc., which are commonly used, are used to extinguish fires using this fire extinguishing principle.

3) Isolation and fire extinguishing: Isolate the combustible material from the ignition source or oxygen, and the combustion reaction will be automatically stopped. In the event of a fire, close the relevant valves and cut off the passage of combustible gases and liquids flowing to the fire area; Opening the valve to allow the liquid combustible material in the container that has burned or is threatened by fire to be piped to a safe area is the application of the principle of isolation and extinguishing of the fire.

4) Chemical inhibition fire extinguishing: It is the use of fire extinguishing agent to react with the intermediate free radicals of the chain reaction, so that the chain reaction of combustion is interrupted and the combustion cannot be continued. Commonly used dry powder fire extinguishing agents and halide fire extinguishing agents are extinguished by using the principle of chemical inhibition fire extinguishing.

1. Cool down.

2. Isolate oxygen.

3. Reduce the content of combustible gas.

4. Chemical fire extinguishing.

Fundamentals of fire prevention and extinguishing.

If it's junior high school chemistry.

The first is that combustibles are isolated from oxygen.

The second is that the temperature of the combustible material is reduced below the ignition point.

Third, remove combustibles or isolate combustibles from other items.

There are four main methods of fire extinguishing principle: cooling fire extinguishing, suffocation fire extinguishing, isolation fire extinguishing, and chemical inhibition fire extinguishing.

1. Cooling and fire extinguishing: Cool to below the ignition point and flash point, such as water, which can absorb a large amount of heat to achieve the cooling effect.

2. Suffocation fire extinguishing: reduce oxygen concentration, such as extinguishing fire with carbon dioxide and water vapor.

3. Isolation and fire extinguishing: Isolate combustibles from oxygen, heat and flame, such as closing the liquefied gas valve and extinguishing the fire with foam.

4. Chemical inhibition fire extinguishing: inhibit the generation of free radicals, such as using dry powder fire extinguishers to extinguish fires.

Fire extinguishing precautions:

When extinguishing a fire with a fire extinguisher, try to stay away from the source of the fire and the fire extinguisher should spray at the root of the flame.

Personnel should stand upwind.

Attention should be paid to the surrounding environment to prevent collapse and **.

(1) Cooling and extinguishing fire: Lower the temperature of the combustible material below the ignition point, and the combustion will stop.

2) Isolation and fire extinguishing: Isolate combustibles from oxygen and flames to stop burning and extinguish fires.

3) Suffocation fire extinguishing: Combustion cannot be carried out if the combustion is below the minimum oxygen concentration, and the fire is extinguished.

4) Chemical inhibition fire extinguishing: inhibiting the generation of free radicals or reducing the concentration of free radicals in the flame can stop combustion.