What conditions must be met to put out the fire with water?

What conditions must be met to put out the fire with water?

What conditions must be met to put out the fire with water? The weather is dry and it is hot in summer, so there are more fires. When putting out a fire, many people will use water to put out the fire. The following are the conditions that must be met when extinguishing fire with water.

What conditions must be met to put out the fire with water? 1 The fire source is clear, the water, manpower and material resources are sufficient, there is a smooth return air duct, and the gas concentration does not exceed 2%.

How does water put out the fire?

First of all, water can lower the temperature below the ignition point. First of all, popularize a knowledge of what is the ignition point and the minimum temperature required for the ignition point to be ignited. That is to say, if the temperature of combustible exceeds the ignition point, once there is oxygen and fire source, combustible will burn. On the contrary, if the temperature of combustible is lower than the ignition point, it will not be ignited at this time. Therefore, one principle of extinguishing fire with water is to lower the temperature below the ignition point, so that the surrounding combustible materials will no longer be ignited, so the fire will gradually decrease.

Water has a large specific heat capacity. To boil a glass of water, he needs to absorb a lot of heat, that is to say, only a small amount of water is needed to put out the fire, and the temperature of many combustible materials can be reduced below the ignition point.

The second principle is to isolate oxygen. When we study chemistry in middle school, the first condition for burning it is combustible, the second is that the temperature reaches the ignition point, and the third is the participation of oxygen. Therefore, the three are indispensable, so when there is a fire, if we use water on the combustible, the water will cover the surface of the combustible and be isolated from the outside oxygen, so that the oxygen will no longer burn with the combustible, so that the fire can be put out in a short time.

But water is not suitable for all fires. For some highly volatile and polluting objects, we generally don't use water to put out the fire. One of the reasons is that water can react with some substances and then increase the fire. For example, there are some metals such as sodium when the laboratory is on fire, and adding water will increase the fire. Therefore, when putting out the fire, we must find out the cause of the fire.

What conditions must be met to put out the fire with water? 2 Four ways to put out the fire.

Cooling fire extinguishing method: the combustion of any substance must reach a certain temperature, and this limit is called the ignition point. Cooling fire extinguishing method is to control the temperature of combustible materials below the ignition point, so as to achieve the purpose of fire extinguishing. Cooling with water is a common and simple fire extinguishing method. Generally, our common fires, such as houses, furniture and wood, can be cooled and put out with water. In addition, carbon dioxide fire extinguishers can also be used for cooling and fire fighting.

Because the carbon dioxide fire extinguisher sprays snowflake-like solid at -78.5℃, carbon dioxide quickly absorbs the heat of burning substances during gasification, thus achieving the purpose of cooling down and stopping combustion. In fire extinguishing practice, in order to effectively control the fire and reduce the fire loss, cooling methods are also commonly used, that is, water or carbon dioxide is used to cool the substances around the fire site to prevent them from reaching the fire point and catching fire.

Asphyxiation fire extinguishing method: As the name implies, it means that the combustibles in the burning area can't get enough oxygen and stop burning. This is also a common fire extinguishing method, which plays a great role in extinguishing the initial fire. This fire extinguishing method can be used for relatively closed fires such as rooms and containers. For example, when the oil pan is on fire, we can cover it in time to isolate the burning oil from the air outside the pan, so as to achieve the purpose of extinguishing the fire.

Isolation fire extinguishing method: this is a kind of fire extinguishing method of "leaving your car behind", which isolates or evacuates the burning object from its nearby combustible materials and eliminates combustible materials, one of the three necessary conditions for combustion, so as to achieve the purpose of fire extinguishing. Isolation fire extinguishing method is suitable for extinguishing all kinds of explosions, fluids, solids and gases, and it is also a common fire extinguishing method.

Suppression fire extinguishing method: also known as chemical blocking method, is to make the extinguishing agent participate in the combustion reaction process, so that the free radicals generated in the combustion process disappear and form stable molecules or low-activity free radicals to stop the combustion reaction. Such as dry powder extinguishing agent to put out gas fire.

What conditions must be met to put out the fire with water? How to put out the fire with water?

First, install the grounding wire on the nozzle of the metal water gun.

The grounding wire can be a soft copper wire with a cross section of 5 5- 10/0mm and a length of 2-5m ... The grounding rod can be an iron pipe or rod of about 1m, and rescuers should wear insulating gloves and rubber boots.

Before live fire extinguishing, the water gunner should firmly connect one end of the grounding wire with the nozzle of the metal water gun and the other end with the grounding rod, and drive the grounding rod into the ground for about 0.5m If the grounding wire is connected with other grounding devices, good contact is required. When holding a water gun, the position of the hand must be placed behind the grounding wire, and the distance from the charged body should be selected, and then the water should be sprayed to extinguish the fire.

Second, wear uniforms.

At present, there are two kinds of uniform clothes: one is warp-weft interwoven cloth made of cotton or animal fiber and copper wire, and the other is made of cotton cloth by electroless copper plating or silver plating. Both of them are packed in cotton yarn or cotton cloth, and both of them contain metal conductors, which are heavy.

Uniforms made of this material include hats, gloves, clothes, socks, uppers and so on. And the sole is made of conductive rubber. When wearing a uniform, be sure to fasten the buttons between clothes, gloves, socks and rubber shoes, so that the copper wires between them can be twisted together to form a good grounding wire, and then choose the water shooting distance according to the voltage, and use a metal water gun to shoot water to extinguish the fire.

Third, wear insulating gloves and boots.

When using running water to put out a fire with insulating gloves and boots, the most experienced water gunner should be selected, the distance between the nozzle of the water gun and the charged body should be expanded as much as possible, measures should be taken to prevent water droplets from flowing into the gloves and rubber boots, standing on the insulating plate and facing the fire source, and water droplets should be made to drop on the fire source by some shooting methods. In general, it is best not to shoot directly at the fire source with a full water column to prevent danger.

Fourthly, spray water flow is adopted.

A two-stage centrifugal nozzle is installed on the muzzle of DC spray gun to become a two-stage centrifugal nozzle. The water sprayed by this kind of water gun has a good atomization degree and is almost non-conductive. The experiment shows that when the nozzle distance of the water gun is 5 meters 127 kV charged body and the fire is put out under the water pressure of 7 kilograms per square centimeter, there is no leakage water flow, and its range can reach 8-9 meters.

When using this spray water gun to extinguish fire with electricity, the water gun can directly extinguish fire with electricity without grounding wire. But the distance should be selected according to the voltage, and the pressure of the fire pump should be kept at 5-7 kg per square centimeter. Only after the atomized water sprayed by the water gun is normal can it be fired at the charged body to extinguish the fire.