Lightning is a phenomenon of large-scale electrostatic discharge in the nature. It has great destructive power and its destructive effects are comprehensive, including the destruction of electrical, thermal and mechanical properties. It can kill people and livestock in an instant; destroy the insulation of electrical equipment such as generators and power transformers, causing short-circuits and fire or explosion accidents. It can be converted into a large amount of heat energy in a very short time, causing the burning of flammable materials or causing the metal to melt and splash and cause fire. Lightning is active at any time on Earth.
First, the formation and type of lightning Lightning is the phenomenon of discharge in the atmosphere, mostly formed in a cumulonimbus cloud, cumulonimbus cloud will continue to move with changes in temperature and airflow, friction generated electricity in the movement, it has formed a charged Clouds. Some clouds have a positive charge and others have a negative charge. In addition, due to electrostatic induction, the buildings, trees, etc. under the clouds often have opposite charges. As the charge accumulates, the voltage of the thundercloud gradually increases. When the thunderclouds with different charges and the earth's projections approach each other to a certain temperature, the electric field between them exceeds 25-30kV/cm, and intense discharge will occur. At the same time there is a strong flash. As the temperature is as high as 2000°C during discharge, the air expands rapidly by heat, and the explosion roar occurs. This is lightning and thunder.
The size and amount of thunder and the activity are related to the terrain, weather conditions and latitude of each area. In general, there are more lightning in the mountains than in the plains. There are more coastal areas than in the hinterland. The higher the buildings, the greater the chance of being struck by lightning.
Lightning can be divided into four types:
(1) Direct lightning strikes Thunder strikes are formed by the discharge between clouds and ground projections.
(2) Spherical Ray Ball Ray is a spherical, red or extremely bright white fireball with a speed of about 2 m/s. Spherical lightning can intrude into the room from doors, windows, chimneys, etc., and is extremely dangerous.
(3) Lightning induction, also called induction Lightning induction is divided into electrostatic induction and electromagnetic induction. Electrostatic induction is caused by the proximity of the thundercloud to the ground and the induction of a large number of opposite charges on the top of the ground projections. Electromagnetic induction is caused by a powerful magnetic field that rapidly changes in the surrounding space after a lightning strike.
(4) Lightning intrusion The wave of electric shock wave is the lightning wave which is rapidly transmitted along the line or pipeline due to the lightning impulse and the voltage generated on the overhead line or the metal pipeline in the sky. Its propagation speed is 3×108m/s. Lightning can destroy the insulation of electrical equipment, causing high pressure to fall into low pressure, causing serious electrical shocks. For example, in thunderstorm days, indoor electrical equipment suddenly exploded, caught fire, or was damaged. People who use electrical appliances in the house or suddenly suffer electric shock when they make a call fall into this type of accident.
The lightning protection measures are mainly to install lightning rods, lightning protection nets, lightning protection strips, lightning conductors, lead wires and grounding devices or ground protection on metal equipment and power supply lines.
Second, the lightning damage to people The lightning harm to people, summed up in four forms, namely: direct lightning, contact voltage, side flash and step voltage.
Direct Lightning Strike: Lightning strikes the human body directly when a lightning strike occurs, because people are a good conductor and lightning currents of up to tens of thousands to tens of thousands of amps flow from the top of the human head through the human body to the feet. Earth. As a result, people were struck by lightning, injured by lightning, severely or even died.
Contact voltage: When lightning currents are discharged through tall objects such as tall buildings, trees, metal structures, etc., powerful lightning currents can generate voltages as high as tens to hundreds of thousands of volts on tall conductors. When people accidentally touch these objects, they are hit by this touch voltage and an electric shock occurs.
Side-by-side flashing: When lightning strikes an object, powerful lightning currents are discharged to the earth through the object. In general, current is the easiest to flow through a small resistance path. The resistance of the human body is very small. If the person is near the object in this lightning strike, the lightning current will be near the height of the human head and will break through the air and then be released by the body. People are attacked.
Stepping voltage: When the lightning discharges from the cloud to the earth, it generates a potential field. The potential distribution is higher near the ground lightning strike point; the potential is lower away from the lightning strike point. If a person strikes a different location on a person's two-footed station during a lightning strike, this potential difference generates a voltage between the person's feet, and there is current flowing through the person's lower limbs. The greater the distance between the legs, the greater the step voltage.
In light of the above four types of thunder and lightning attacks on people, in various situations, appropriate measures should be taken to prevent it.
Third, personal lightning protection measures (1) indoor lightning strikes.
1 The outdoor antenna of the TV is disconnected from the TV in thunderstorm days, and is connected to the grounding wire.
2 The doors and windows should be closed in thunderstorm days to prevent the spherical lightning from entering the house and causing damage.
3 When a thunderstorm occurs, the human body is best to leave more than 1.5m of lines and equipment that may have transmitted lightning waves into the waves. Unplug the power plug; do not call; do not close to the indoor metal equipment such as radiators, water pipes, water pipes; try to leave the power cord, telephone line, broadcast line, in order to prevent secondary discharge of these lines and equipment to the human body. In addition, do not wear wet clothing and do not go near wet walls.
(2) Avoid lightning strikes outdoors.
1 Keep the lightning rod and its ground lead off the building.
2 to stay away from all kinds of antennas, telephone poles, towers, chimneys, flagpoles, and if possible vehicles and boats that have large metal structures and buildings or metal shells with lightning protection facilities, should stay away from the canopy cars and tractors. Motorcycles and so on.
3 It should be possible to leave the hills, the seashore, the river, and the pool; leave the barbed wire, metal clothesline, isolated trees and isolated small buildings without lightning protection devices as soon as possible.
4 Do not walk in the wilderness during thunderstorms. Wear plastic and other raincoats that do not invade the water; take slower steps and smaller steps; don't ride on bicycles; don't use umbrellas with metal rods or tools with metal rods on the shoulders.
Before being struck by lightning, five people suddenly have hair sensation or skin tremors. They should immediately lie down on the ground, or choose to kneel down at low squat, feet close together, arms around knees, head down, try to Reducing the exposed surface can be.
4. Methods of Lightning Strike and Rescue The person who was burned or severely shocked by a lightning strike does not have the power. He should be allowed to lie down immediately to extinguish the fire and rescue him. If the injured person loses consciousness, but still has breathing or heartbeat, there is a high possibility of self-recovery. The injured person should be comfortable and supine. After a quiet rest, he will be sent to the hospital for treatment. If the victim has stopped breathing or the heart is beating, he or she should immediately undergo mouth-to-mouth artificial respiration and cardiac massage. He must continue the first aid for CPR on the way to the hospital.
First, the formation and type of lightning Lightning is the phenomenon of discharge in the atmosphere, mostly formed in a cumulonimbus cloud, cumulonimbus cloud will continue to move with changes in temperature and airflow, friction generated electricity in the movement, it has formed a charged Clouds. Some clouds have a positive charge and others have a negative charge. In addition, due to electrostatic induction, the buildings, trees, etc. under the clouds often have opposite charges. As the charge accumulates, the voltage of the thundercloud gradually increases. When the thunderclouds with different charges and the earth's projections approach each other to a certain temperature, the electric field between them exceeds 25-30kV/cm, and intense discharge will occur. At the same time there is a strong flash. As the temperature is as high as 2000°C during discharge, the air expands rapidly by heat, and the explosion roar occurs. This is lightning and thunder.
The size and amount of thunder and the activity are related to the terrain, weather conditions and latitude of each area. In general, there are more lightning in the mountains than in the plains. There are more coastal areas than in the hinterland. The higher the buildings, the greater the chance of being struck by lightning.
Lightning can be divided into four types:
(1) Direct lightning strikes Thunder strikes are formed by the discharge between clouds and ground projections.
(2) Spherical Ray Ball Ray is a spherical, red or extremely bright white fireball with a speed of about 2 m/s. Spherical lightning can intrude into the room from doors, windows, chimneys, etc., and is extremely dangerous.
(3) Lightning induction, also called induction Lightning induction is divided into electrostatic induction and electromagnetic induction. Electrostatic induction is caused by the proximity of the thundercloud to the ground and the induction of a large number of opposite charges on the top of the ground projections. Electromagnetic induction is caused by a powerful magnetic field that rapidly changes in the surrounding space after a lightning strike.
(4) Lightning intrusion The wave of electric shock wave is the lightning wave which is rapidly transmitted along the line or pipeline due to the lightning impulse and the voltage generated on the overhead line or the metal pipeline in the sky. Its propagation speed is 3×108m/s. Lightning can destroy the insulation of electrical equipment, causing high pressure to fall into low pressure, causing serious electrical shocks. For example, in thunderstorm days, indoor electrical equipment suddenly exploded, caught fire, or was damaged. People who use electrical appliances in the house or suddenly suffer electric shock when they make a call fall into this type of accident.
The lightning protection measures are mainly to install lightning rods, lightning protection nets, lightning protection strips, lightning conductors, lead wires and grounding devices or ground protection on metal equipment and power supply lines.
Second, the lightning damage to people The lightning harm to people, summed up in four forms, namely: direct lightning, contact voltage, side flash and step voltage.
Direct Lightning Strike: Lightning strikes the human body directly when a lightning strike occurs, because people are a good conductor and lightning currents of up to tens of thousands to tens of thousands of amps flow from the top of the human head through the human body to the feet. Earth. As a result, people were struck by lightning, injured by lightning, severely or even died.
Contact voltage: When lightning currents are discharged through tall objects such as tall buildings, trees, metal structures, etc., powerful lightning currents can generate voltages as high as tens to hundreds of thousands of volts on tall conductors. When people accidentally touch these objects, they are hit by this touch voltage and an electric shock occurs.
Side-by-side flashing: When lightning strikes an object, powerful lightning currents are discharged to the earth through the object. In general, current is the easiest to flow through a small resistance path. The resistance of the human body is very small. If the person is near the object in this lightning strike, the lightning current will be near the height of the human head and will break through the air and then be released by the body. People are attacked.
Stepping voltage: When the lightning discharges from the cloud to the earth, it generates a potential field. The potential distribution is higher near the ground lightning strike point; the potential is lower away from the lightning strike point. If a person strikes a different location on a person's two-footed station during a lightning strike, this potential difference generates a voltage between the person's feet, and there is current flowing through the person's lower limbs. The greater the distance between the legs, the greater the step voltage.
In light of the above four types of thunder and lightning attacks on people, in various situations, appropriate measures should be taken to prevent it.
Third, personal lightning protection measures (1) indoor lightning strikes.
1 The outdoor antenna of the TV is disconnected from the TV in thunderstorm days, and is connected to the grounding wire.
2 The doors and windows should be closed in thunderstorm days to prevent the spherical lightning from entering the house and causing damage.
3 When a thunderstorm occurs, the human body is best to leave more than 1.5m of lines and equipment that may have transmitted lightning waves into the waves. Unplug the power plug; do not call; do not close to the indoor metal equipment such as radiators, water pipes, water pipes; try to leave the power cord, telephone line, broadcast line, in order to prevent secondary discharge of these lines and equipment to the human body. In addition, do not wear wet clothing and do not go near wet walls.
(2) Avoid lightning strikes outdoors.
1 Keep the lightning rod and its ground lead off the building.
2 to stay away from all kinds of antennas, telephone poles, towers, chimneys, flagpoles, and if possible vehicles and boats that have large metal structures and buildings or metal shells with lightning protection facilities, should stay away from the canopy cars and tractors. Motorcycles and so on.
3 It should be possible to leave the hills, the seashore, the river, and the pool; leave the barbed wire, metal clothesline, isolated trees and isolated small buildings without lightning protection devices as soon as possible.
4 Do not walk in the wilderness during thunderstorms. Wear plastic and other raincoats that do not invade the water; take slower steps and smaller steps; don't ride on bicycles; don't use umbrellas with metal rods or tools with metal rods on the shoulders.
Before being struck by lightning, five people suddenly have hair sensation or skin tremors. They should immediately lie down on the ground, or choose to kneel down at low squat, feet close together, arms around knees, head down, try to Reducing the exposed surface can be.
4. Methods of Lightning Strike and Rescue The person who was burned or severely shocked by a lightning strike does not have the power. He should be allowed to lie down immediately to extinguish the fire and rescue him. If the injured person loses consciousness, but still has breathing or heartbeat, there is a high possibility of self-recovery. The injured person should be comfortable and supine. After a quiet rest, he will be sent to the hospital for treatment. If the victim has stopped breathing or the heart is beating, he or she should immediately undergo mouth-to-mouth artificial respiration and cardiac massage. He must continue the first aid for CPR on the way to the hospital.
Kitchen Faucets With Sidespray
Kitchen Faucets With Sidespray,Kitchen Faucets With Sidespray Price,Kitchen Faucets With Sidespray Product
Yuyao Zelin Sanitary Ware Co., Ltd , https://www.kitchen-sinkfaucet.com