Fire and explosion emergency response (2)

6.

In the process of fire development, the initial stage is the most favorable stage for fire fighting and rescue.

(1) Principles of initial fire suppression

In the initial fire fighting, the following principles must be followed: the principle of first control and then eradication; the principle of saving people first; the principle of focusing manpower; the principle of focusing first and general

(1) Control first and then extinguish it means that for fires that cannot be extinguished immediately, the continuous spread and expansion of the fire must be controlled first, and when the conditions for extinguishing the fire are met, a full-scale extinguishment is carried out and extinguished in one fell swoop

(2) Rescue first means that if someone in the fire scene is surrounded by the fire, the first task of emergency personnel or firefighters is to rescue the trapped personnel from the fire scene.

(3) Concentrated manpower means that the person in charge of on-site fire extinguishing must concentrate the fire extinguishing force in the center of the fire site according to the fire extinguishing plan, and use the fire extinguishing equipment intensively to help extinguish the fire in the shortest time

(4) Focus first and then generally means that in the initial stage of fighting a fire, it is necessary to fully understand the situation of the fire site, and distinguish the key points from the general: compared with people and things, people are the key points; valuable materials are compared with general materials, and valuable materials are the key points; fire scenes Compared with the upwind direction and the downwind direction, the downwind direction is the key point: Compared with other parts, the key parts are the key points; compared with the normal areas, the areas with explosion poisoning and collapse risk are the key points.

It is relatively easy to put out a fire in the early stage, and the basic countermeasures and principles are the same.

(2) Fire fighting measures

Material combustion must meet three conditions (combustibles, combustion-supporting gas, fire source or latent fire source) at the same time.

According to the principle of material combustion, the basic methods of fire extinguishing can be summarized into four types, namely, cooling fire extinguishing method, suffocation fire extinguishing method, isolation fire extinguishing method and suppression fire extinguishing method

1.

The cooling fire extinguishing method is to spray the fire extinguishing agent directly on the combustible object, and reduce the temperature of the combustible material below the ignition point of the object to stop burning.

2.

The suffocation fire extinguishing method is to take appropriate measures to prevent air and oxygen from entering the combustion zone or dilute the oxygen content in the air with inert gas, so that the burning material lacks or cuts off the oxygen and extinguishes

(1) Use fire-extinguishing blankets, fire-fighting sand and other non-combustible or non-combustible materials to cover the burning material

(2) For a fire in the container, directly seal the mouth of the container with the lid of the container

(3) Use the original doors and windows of the building and the parts on the production, storage and transportation equipment to close the combustion area and prevent the entry of fresh air
.

3.
Isolation fire extinguishing method

The isolation fire extinguishing method is to isolate the combustibles from nearby combustibles or evacuate them to a safe place, so as to stop the combustion
.
This method is suitable for fighting various solid, liquid, gas and electrical fires.
There are many measures to isolate and extinguish fires, as follows:

(1) Transfer flammable and explosive materials near the fire source to a safe place
.

(2) Close the valve on the equipment or pipeline to prevent combustible gas and liquid from flowing into the combustion zone
.

(3) Eliminate combustible gases and liquids in production equipment and containers
.

(4) Prevent and evacuate combustible liquids or diffuse combustible gases
.

(5) Eliminate the flammable building structure connected to the fire source and create a space zone that prevents the fire from spreading
.

4.
Suppress fire extinguishing method

The suppression fire extinguishing method is to spray a chemical fire extinguishing agent into the combustion zone to participate in the combustion reaction, terminate the combustion chain reaction and stop the combustion reaction
.
This method can be used with dry powder and carbon dioxide fire extinguishers; sufficient fire extinguishing agent must be sprayed in the combustion zone to make the fire extinguishing agent participate in preventing the combustion reaction and extinguish it in one blow.
When taking fire-retardant measures, the necessary cooling must be taken at the same time Refers to the application to prevent re-ignition
.

The specific method used to extinguish the fire should be determined according to the state of the burning material, the characteristics of the fire, the situation of the fire scene and the performance of the fire fighting equipment
.

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