Several methods of extinguishing the fire of live equipment with water

With the improvement of people's living standards in China, the electricity consumption in urban and rural areas has increased sharply in recent years, and fires caused by electrical equipment or lines have occurred frequently, especially in Northeast China. In winter, due to the low weather temperature, the use of electrical products for heating causes the line to be overloaded or the use of electrical appliances neglects to turn off the switch in time, which leads to an increase in fires.

Water can conduct electricity. Using the water column of DC water gun to extinguish the fire of live electrical equipment is harmful to the health of firefighters. Therefore, in fire fighting, when the equipment is charged, we generally have to cut off the power supply first and then put out the fire. However, when the power supply cannot be cut off due to production or other reasons, it is necessary to use electricity to extinguish the fire.

When water is charged to extinguish a fire, a current loop will be formed between the charged body and the ejected water column, water gun, human body and ground, and the current passing through this loop has a direct impact on the safety of human body. If we directly lead the current obtained by water column and water gun into the earth and add insulation protection to human body, then the safety of firefighters can be guaranteed. Here are several ways to put out the fire with running water.

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

The grounding wire can be a copper stranded wire with a section of 5-65438+ 100m2 and a length of 5-10m2. Grounding rod can be made of steel pipe with a diameter of 50㎜ or angle steel with a diameter of 50×50㎜, 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, nail the grounding rod into the ground for about 0.5 meters, and inject salt water or ordinary water into the grounding rod. 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 insulating gloves and boots.

When wearing insulating gloves and boots to put out the charged fire with water, the most experienced water gunner should be selected to maximize the distance between the nozzle of the water gun and the charged body. Effective measures should be taken to prevent water droplets from flowing into gloves and rubber boots, standing on the insulation board and facing the fire source, and making water droplets drop on the fire source by some methods. In general, it is best not to shoot directly at the fire source with a full water column to prevent the danger of electric shock.

Third, wear uniform clothes.

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.

Fourthly, spray water flow is adopted.

Choosing a spray gun or installing a two-stage centrifugal nozzle on the muzzle of a DC spray gun becomes a two-stage centrifugal spray gun. 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. However, the safe distance from the charged body should be selected according to the voltage, and the pump pressure of the fire truck should be kept at 0.5-0.7 MPa. Only after the atomized water sprayed by the water gun is normal can it be fired at the charged body to extinguish the fire.

Verb (abbreviation of verb) Specific measures for live fire extinguishing.

1, determine the voltage of live equipment and lines.

The fire commander should get in touch with the person in charge of the unit or the electrician, find out the voltage of fire-fighting equipment and lines, determine the minimum safe distance from them, and then organize fire fighting. For power supply with voltage lower than 250V, wear insulating gloves and cut wires with insulating electric scissors.

After consulting the data, the minimum safe distance between human body and live equipment and lines is: 1 10 kV is greater than1m; 220kV is greater than1.8m; 330 kV is more than 2.4 meters.

2. Use gas or dry powder fire extinguishers.

For the fire of electrified equipment or lines with small scale and scope, carbon dioxide, 12 1 1, FM200 or dry powder fire extinguisher can be directly sprayed to extinguish the fire. In view of the complex fire situation, in order to ensure safety, human body and fire extinguisher must be far away from live equipment and lines to prevent electric shock casualties caused by stepping voltage or reaching discharge gap.

3, enable the fixed fire extinguishing device.

There are three main types of fixed fire extinguishing devices usually installed in power facilities: steam fire extinguishing devices; Gas fire extinguishing device; Water spray fire extinguishing device. After the fire brigade arrives at the scene, the fire commander should ask and check whether the fixed fire extinguishing device is enabled. If not, it should be enabled as appropriate.

4, the use of spray water gun charged fire.

Adjust the pump pressure of the fire truck to above 0.7MPa, and then aim at the charged target to extinguish the fire after the water sprayed by the spray gun becomes foggy.

5. Use DC water gun to extinguish the fire with electricity.

In the absence of charged fire extinguishing equipment and spray water gun, DC water gun can be used to spray a full water column, and tap water can also be used to extinguish the fire of high-voltage charged equipment or lines within 220 kV.

The specific method is: use a large-caliber water gun, stand 7 meters away from the charged object, and the water gun wears insulating boots and gloves to shoot water from a distance to extinguish the fire or make the water flow fall on the fire point in a parabolic shape.

6, the use of foam tube gun charged fire.

The foam sprayed by tap water and ordinary protein foam liquid through foam pipe gun has a good extinguishing effect on high voltage live fire, and its resistivity is much higher than tap water, which is most suitable for extinguishing large power transformer and cable trench fires.

Six, fire safety precautions

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2, water gunner had better wear insulating gloves, wear insulating boots, overalls and other safety protection articles, other personnel shall not be close to firefighters, fire areas and waters.

3. The nozzles of water guns and fire extinguishers and the human body must keep a corresponding safe distance from high-voltage charged equipment or lines.

4. When fighting the fire of overhead high-voltage electrified equipment or lines, the water gunner should keep a horizontal distance from the electrified body as far as possible to prevent the disconnection from endangering safety. When the live high-voltage line is disconnected, a warning zone should be set up within a radius of 20 meters from the drop point, and no one is allowed to enter. People who are already in this field should be treated calmly. In order to prevent the injury of step voltage, they must first throw away the equipment in their hands, one foot or two feet together and slowly jump away from the charged body, and then get out of danger.

5. Firefighters who carry out blasting operations near high-voltage electrified equipment or lines should also keep a necessary safe distance from electrified bodies and prevent blasting tools from contacting electrified bodies.

6, in the transformer room (box) to cut off the power supply, the face should be back to the knife, in case of arc cuts. Designate a special person to guard after the power failure to prevent the uninformed person from switching on and off at will.

7. When using DC water gun to extinguish fire, if there is discharge sound, spark or electric shock, spray water in prone position and touch the joint between hose and water gun with metal to prevent electric shock.

8. When fighting fires of high-temperature electric heating equipment such as industrial electric furnaces, electric ovens and electric drying rooms, gas or dry powder fire extinguishers should be used, and water is strictly prohibited. Because sudden cooling will damage the electric heating equipment at high temperature, and the rapid evaporation and gasification of water after contacting the high temperature electric heating equipment will cause explosion and charge splash, resulting in casualties or new ignition points.