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Fire science thesis

Water to fight a fire with electric equipment in several ways

With China's people's living standards are increasingly improving, in recent years, urban and rural electricity consumption has increased steeply, due to electrical equipment or lines caused by the frequent occurrence of fires, especially in the Northeast in winter, due to the lower weather temperatures, the large number of electrical appliances used for warming products caused by the overloading of the line or the use of electrical appliances paralysis Forget to turn off the switch in time and the fire increased.

Water can conduct electricity, with the DC water gun water column to fight the electrical equipment charged fire, the firefighters are harmful to the body. Therefore, in the fire fighting in the case of charged equipment, we generally have to cut off the power supply, and then fight. However, due to production or other reasons can not cut off the power supply, it is necessary to electric fire extinguishing.

When using charged water to extinguish fire, the charged body and the jet of water, water gun, the human body and the ground will form a current loop, the circuit through the current size of the human body has a direct impact on the safety. If we will be the water column, water gun on the current obtained directly into the earth, the human body plus insulation protection, then you can guarantee the safety of rescue personnel. Here are several ways to use water with electricity to extinguish the fire.

One, in the metal water gun nozzle installed on the grounding line

Grounding line can be used cross-section 5-10m ㎡, more than 1m long copper stranded wire. Grounding rod can be more than 1m, 50mm diameter steel pipe or 50 × 50mm angle, fighting personnel wearing insulated gloves and insulated rubber boots. Before putting out the fire with electricity, the water gunner should firmly connect one end of the grounding wire to the metal water gun nozzle, and connect the other end with the grounding rod, and nail the grounding rod into the ground about O.5 meters, and pour salt water or ordinary water at the grounding rod. If the grounding wire connected to other grounding devices, it is required to make good contact, holding a water gun when the position of the hand must be placed behind the grounding wire, choose a good distance from the electrified body, and then shoot water to save.

Two, wearing insulated gloves, insulated boots

Wearing insulated gloves and insulated boots to extinguish electrified fires with water, to choose the most experienced water gunner, as far as possible to expand the distance between the nozzle of the water gun to the electrified body, to take effective measures to prevent water droplets into the gloves and rubber boots, standing on the insulated board, facing the source of the fire to the method of pointing and shooting, so that the droplets of water falling on the source of the fire. In general, it is best not to use the water column filled directly to the fire source to prevent the risk of electrocution

Three, wearing pressure uniform

Currently there are two types of pressure uniform: one is cotton fiber or animal fiber and copper wire twisted warp and weft interwoven cloth made of another is made of cotton by chemical copper-plated or silver-plated. These two kinds of uniform pressure clothing in the cotton yarn or cotton cloth inside, all contain a large component of the metal conductor. Homogeneous suits made from this material include: hats, gloves, clothing, socks, shoe uppers, etc., while the soles of shoes are made of conductive rubber. When wearing pressure-even clothing, be sure to clothes, gloves, socks and rubber shoes between the snap button, so that they are screwed together with each other's copper wires to form a good grounding line, and then according to the size of the voltage to choose a good distance to shoot the water, the use of metal water guns to shoot water to fight.

Four, the use of spray water

Spray water gun or DC water gun installed on the muzzle of a two-stage centrifugal spray head, that is, become a two-stage centrifugal spray water gun. This water gun shot water flow, atomization is good, almost non-conductive. Experiments have proved that when the nozzle of the water gun from the 127 kV charged body 5 meters, and 7 kg per square centimeter of water pressure for charged fire extinguishing, there is no leakage of water flow, its range up to 8-9 meters.

With this spray water gun for charged fire, the water gun can not be grounded, directly charged fire. But according to the size of the voltage to choose a good safety distance from the electrified body, the fire engine pump pressure should be maintained 0.5-0.7Mpa, and in the water gun spray mist water normal before shooting to the electrified body to put out the fire.

Five, electric fire fighting specific measures

1, to determine the voltage of the charged equipment, lines

The fire commander should get in touch with the person in charge of the unit or the electrician to clarify the fire equipment, line voltage, to determine the minimum safe distance that should be maintained with it, and then organize the fire fighting. For the voltage below 250V power supply, you can wear insulated gloves and cut the wires with insulated electric scissors.

After reviewing the information, the human body and electrified equipment, lines must maintain the minimum safe distance for: 110 kV is more than 1 meter; 220 kV is more than 1.8 meters; 330 kV is more than 2.4 meters.

2, the use of gas or dry powder fire extinguishers

On the scale and scope of the smaller charged equipment or line fires, you can use carbon dioxide, 1211, FM200, or dry powder fire extinguishers directly spray fire. In view of the complexity of the fire, to ensure safety, the human body and fire extinguishers must be far away from the energized equipment and lines, in order to prevent cross-step voltage or reach the discharge gap and lead to electric shock casualties.

3, enabling fixed fire extinguishing devices to extinguish the fire

Electric power facilities are usually installed fixed fire extinguishing devices are mainly the following three: steam fire extinguishing devices; gas fire extinguishing devices; water spray fire extinguishing devices. After the fire department 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 gun charged fire

The fire engine pump pressure to 0.7MPa or more, to be sprayed water gun shot water into the atomized state, and then directed at the charged target fire.

5, the use of DC water gun charged fire

In the absence of charged fire-fighting equipment and spray gun, DC water gun spray filled water column, the use of tap water can also be emergency extinguishing 220 kV within the high-voltage energized equipment or line fires.

Specific method is: the use of large-caliber water gun, standing 7 meters away from the electrified objects, water gunner wearing insulated boots, wearing insulated gloves, the use of point-blank shooting for long-distance water jetting or make the water flow in a parabolic fall on the fire point.

6, the use of foam pipe gun charged fire

The use of tap water and ordinary protein foam through the foam pipe gun sprayed out of the foam extinguishing high-voltage energized fire effect is also very good, the resistivity is much larger than the tap water, the most suitable for fighting large-scale power transformers, cable trench fire.

Six, fire safety precautions

1, with the foam charged fire need to pay attention to, in the absence of the formation of foam can not impact the charged body, the foam flow area can not be someone to prevent leakage of electric current injury.

2, the water gunner better wear insulated gloves, wear insulated boots, pressure uniforms and other safety equipment, other personnel shall not be close to the firefighters who are extinguishing the fire, the burning area and the water area.

3, water gun nozzle, fire extinguishers and the human body and high-voltage energized equipment or lines must maintain a corresponding safety distance.

4, fighting overhead high-voltage energized equipment or line fire, the water gunner should be as far away as possible from the energized body between the horizontal distance, to prevent wire breakage and endanger the safety. When an electrified high-voltage power line breaks down, to set up a cordon area outside a radius of 20 meters from the point of fall of the wire, prohibiting personnel from entering the area. Has been in the area of the personnel to be disposed of calmly, in order to prevent cross-step voltage injury, to first throw away the hands of the equipment, with one foot or both feet together slowly jump away from the electrified body touched 10 meters away, you can get out of danger.

5, in the high-voltage energized equipment or lines near the firefighters to break down the body and the use of equipment and energized body to maintain the necessary safety distance, to prevent the break down of tools and energized body contact.

6, in the distribution room (box) when cutting off the power supply, the face should be back to the gate, to prevent electric arc injury. After the power cut should be designated to guard, to prevent uninformed people arbitrarily close the gate energized.

7, the use of DC water gun fire, such as the discovery of discharge sound or discharge sparks, a sense of electric shock, take a prone position to shoot the water, the water belt and the water gun will be the joint metal touch the ground to prevent electric shock injury.

8, fighting industrial furnace, electric oven, electric drying room and other high-temperature electrical equipment fire, should use gas or dry powder fire extinguishers, water is strictly prohibited. Because the sudden cooling will damage the high temperature of the electrical equipment, while water contact with high-temperature electrical equipment after rapid evaporation and gasification will cause explosions and furnace material splash, resulting in casualties or new fire point.