The basic method of fire extinguishing, that is, according to the state and manner of combustion of the fire material, in order to destroy the basic conditions that must be available for combustion and take some measures. Specifically, the following four methods.
(1) cooling method of fire extinguishing. The cooling method is the fire extinguishing agent is sprayed directly on the combustible material, so that the temperature of the combustible material is reduced to below the point of spontaneous combustion so that the combustion stops. Fire fighting with water, its main role is to cool the fire. General material on fire can be used to cool the fire.
Fire, in addition to the cooling method of direct extinguishing, but also often use water to cool the combustible material that has not yet burned, to avoid its spontaneous combustion point and fire; also available water cooling building components, production equipment or containers, etc., to prevent its heat deformation or explosion.
(2) isolation fire extinguishing method. The isolation fire extinguishing method is to isolate or evacuate the burning material and nearby combustible materials so that the burning stops. This method is suitable for fighting all kinds of solid, liquid, and gas fires. Take a number of specific measures to isolate the fire. For example, the fire source near the flammable and explosive substances bought to a safe location; close the valve on the equipment or pipeline to prevent combustible gases, substances than into the combustion area; exclude the production of devices and containers of combustible gases, liquids; block the liquid dispersion of combustible liquids or diffusion of combustible gases; remove the flammable building structures adjacent to the source of the fire, resulting in space to prevent the spread of fire.
(3) asphyxiation method. Suffocation method is to take appropriate measures to prevent air into the burning area, or with the help of inert gas dilution of the oxygen content of the air so that the lack of burning material or cut off the oxygen and extinguished. This method is suitable for fighting fires in enclosed spaces, production equipment, devices, and containers.
When using the asphyxiation method to fight fires, asbestos quilts, wet sacks, wet quilts, sand and foam, and other non-combustible or non-combustible materials can be used to cover the burning material or close the hole; water vapor and inert gases (such as carbon dioxide, nitrogen, etc.) to fill the burning area; with the original doors and windows on the building and production and storage equipment components to close the burning area to prevent the entry of air. In addition, in the inability to take other methods of firefighting and conditions allow, you can use the water flooding (infusion) method of firefighting. But in taking the asphyxiation method to extinguish the fire, the following points must be noted.
① burning parts are small, easy to plug closed, no oxidant in the burning area, suitable for this method.
② in taking water inundation or infusion method to extinguish the fire must take into account the fire material by water submersion can produce adverse consequences.
③ after taking the asphyxiation method to extinguish the fire must confirm that the fire has been extinguished, before opening the hole for inspection. Prevent the premature opening of closed spaces or production devices, and the entry of air, resulting in re-ignition or explosion.
(4) the use of inert gas fire must be filled with a large amount of inert gas-burning area, quickly make the oxygen content of the air to reduce the purpose of asphyxiation fire.
(4) inhibit fire extinguishing method. The suppression method is the chemical fire extinguishing agent sprayed into the combustion area to participate in the combustion reaction, the termination of the chain reaction to stop the combustion reaction. Using this method can be used to extinguish agents are dry powder and halogenated extinguishing agent. When extinguishing the fire, a sufficient amount of extinguishing agent will be accurately sprayed into the combustion zone, so that the extinguishing agent to interrupt the combustion reaction, but also to take the necessary cooling measures to avoid re-ignition.
In the fire to take which fire extinguishing method, should be based on the nature of burning materials, combustion characteristics, the specific circumstances of the fire, and the performance of fire-fighting equipment and equipment to choose.