The gas tank explosion at a barbecue restaurant in Yinchuan has killed 31 people! If a gas tank catches fire or explodes, how can you save yourself?

On the evening of June 21, a gas explosion occurred in Yinchuan, Ningxia. Why did the liquefied petroleum gas leak? Why was the explosion so powerful? If a gas tank catches fire or explodes, how can you save yourself? Let's take a look at the details...

Compiled by Zhang Hongwei, New Media Editor

At around 20:40 on June 21, a liquefied petroleum gas (liquefied gas tank) leaked in the operation room of Fuyang BBQ Restaurant on Minzu South Street, Xingqing District, Yinchuan City, Ningxia Hui Autonomous Region, causing an explosion, resulting in 38 casualties, of which 31 died after failed rescue efforts and 7 are currently being treated.

▲The explosion scene at a barbecue restaurant in Xingqing District, Yinchuan, Ningxia (Photo source: Xinhuanet)

Another gas explosion with heavy casualties. In recent years, casualties caused by gas explosions have occurred from time to time:

On September 17, 2022, a gas tank exploded in a barbecue restaurant in Huai'an, Jiangsu. The accident caused 1 death, 1 serious injury, and 4 minor injuries.

On June 24, 2022, a liquefied petroleum gas cylinder exploded at a merchant in Sanhe, Hebei, injuring 22 people, two of whom died after failed rescue efforts.

On June 21, 2022, an explosion occurred in a store in Tai'an, Shandong due to a leak in a liquefied gas tank, injuring 13 people, three of whom died after rescue efforts failed.

On June 1, 2022, an explosion occurred in a restaurant in Harbin, Heilongjiang, injuring five people. It was determined that the liquefied gas tank (gas tank) leaked, which caused a flash explosion after ignition.

On the evening of May 24, 2022, an explosion occurred in a residential building in Changzhou, Jiangsu, killing one person and injuring five.

On the morning of October 13, 2019, a gas explosion occurred in a snack bar on Xinyang Road, Ehu Town, Xishan District, Wuxi City, Jiangsu Province, killing 9 people and injuring 10.

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Why does liquefied petroleum gas explode?

The main factor in assessing the explosion risk of liquefied petroleum gas is its concentration in the air when it leaks - the lower explosion limit is 1.5% and the upper explosion limit is 9.65%. When it changes from liquid to gas, its volume expands by 250-350 times. The gas density is relatively large, about 1.5-2 times that of air. When it leaks, it will settle downwards and in low-lying areas and will not easily disperse. The minimum ignition energy is 0.2-0.3 mJ, and it is very easy to explode when mixed with air.

Why does liquefied petroleum gas leak?

This is mainly because the hose is aging, loose, or the valve is not closed tightly (falling off), or the liquefied gas tank may be broken. Pay special attention when using liquefied gas, and preventing leakage is the most important thing. Check more often and replace aging pipes and valves in time. Liquefied gas tanks should also be inspected regularly and replaced in time if they are aging or damaged.

When a leak occurs in a liquefied gas pipeline or valve, on-site personnel must immediately close the valve of the liquefied gas tank and prohibit open flames to prevent explosions to the greatest extent possible. If the liquefied gas tank ruptures and a large amount of liquefied gas leaks, on-site personnel must flee immediately without hesitation. Since liquefied gas explosions can cause fires, smoke and fire will spread rapidly and close the stairwell, causing serious threats to people above the explosion area. At this time, it is difficult for people upstairs to evacuate, and as a restaurant, doors and windows that can be opened should be set up in the upstairs area to minimize casualties.

How powerful is a gas tank explosion?

"Gas cylinders" have entered people's lives with advantages such as less pollution, high heat, easy transportation and simple storage, but they also have hidden dangers: in case of leakage and explosion, it will cause great harm to the human body. It can be said that it is the "dangerous goods" closest to our lives.

Liquefied petroleum gas is a mixture of propane and butane, accompanied by a small amount of propylene and butylene, etc. A strong odorant, ethyl mercaptan, is usually added so that a leak can be easily detected.

Data shows that the calorific value of 1 kg of liquefied petroleum gas is about 46,100 kilojoules, and the explosion energy of 1 kg of TNT is about 4,200 kilojoules. Therefore, the explosion of a 15 kg household gas cylinder is equivalent to the energy of 150 kg of TNT. A hand grenade contains about 50 grams of TNT, which means that the explosion heat of a full household gas cylinder is equivalent to 3,000 hand grenades, enough to blow up a two-story building.

"Gas explosions are extremely powerful because once they explode they will produce two explosions: one is a physical explosion and the other is a chemical explosion." Tang Wei, deputy manager of Chongqing Kaiyuan Gas Beixin Branch, said that a natural gas explosion is first a physical explosion: the gas in the gas tank is under high pressure. Once the gas tank ruptures, a shock wave is generated, blowing the entire gas tank apart. These fragments are accelerated to a maximum of 500 meters per second, posing a huge threat to surrounding objects. The second is a chemical explosion: when gas leaks into the air and reaches a certain concentration, it will cause violent combustion and then explode.

When a gas tank catches fire, should you close the valve first or put out the fire?

The Fire Rescue Bureau of the Ministry of Emergency Management introduced that once a liquefied gas cylinder catches fire, different disposal measures can be taken according to the situation at the scene.

The first one is that if the valve of the liquefied gas cylinder is intact, the first choice is to close the valve. When the valve is closed, the fire will be extinguished. The situation circulating on the Internet, "first extinguish the fire, then close the valve, otherwise it will backfire and cause an explosion", will not happen when the liquefied gas cylinder is on fire.

Only when the gas pipeline is on fire, if the valve is closed quickly, the pressure in the pipeline will drop rapidly, and the pressure outside the pipeline will be greater than the pressure inside, which will press the fire into the pipeline and cause a flashback. When firefighters deal with a gas pipeline fire, they will first slowly close the pipeline valve to the minimum state, reduce the flame to the minimum, and then close the valve to extinguish the fire. This is to prevent flashback. The body and mouth of the liquefied gas cylinder are relatively small, and the pressure is relatively small, so there will be no pressure difference, and the pressure inside the liquefied gas cylinder is greater than the outside.

The second method is, if the valve of the burning liquefied gas cylinder is damaged, you do not need to extinguish the fire. First, carry the liquefied gas cylinder to an open area and place it standing, then use water to cool the bottle body, and wait for the liquefied gas to burn out. If the burning liquefied gas cylinder cannot be moved from the resident's home, you can first extinguish the fire, then block the bottle mouth with a wet rag or other items, and send it to a professional liquefied gas station for disposal.

The third type is that if the liquefied gas cylinder falls horizontally and burns, the ground will be heated by the flames, which will easily cause heat to be transferred to the bottle body. When the bottle body reaches a certain temperature, the liquefied gas in the bottle will expand due to the heat, causing a physical explosion.

(Photo source: Science Popularization China)

Keep in mind these nine tips to prevent fires before they happen

According to the nine tips for gas safety issued by the Fire and Rescue Bureau of the Ministry of Emergency Management, gas leaks and explosions are more likely to occur in summer. Please pay attention to these when using gas↓

How to save yourself and each other after an explosion?

[Self-rescue in case of explosion in public places]

1. Take cover. When an explosion is about to occur, take cover or lie down nearby to protect important parts.

2. Fire extinguishing. Find a fire extinguisher nearby to extinguish the fire. If the fire is too large to extinguish, cover your mouth and nose with a mask, handkerchief or clothing corner. If the smoke in a confined space is too pungent, moisten a piece of cloth with mineral water or beverages to prevent suffocation caused by smoke and toxic gases.

(Photo source: National Emergency Broadcasting Network)

3. Evacuate. If a large number of people evacuate in a panic, the elderly, women, and children should try to "slip to the side" to prevent being squeezed and stepped on; when there are crowds of people, hold the wrist of the other hand with one hand, open your elbows, place them flat on your chest, bend forward slightly, create a certain space, ensure smooth breathing, and avoid suffocation and fainting. If you are squeezed, try to get your body close to the wall or other support, curl up into a ball, clasp your hands behind your neck, and protect important parts or organs of your body.

4. Rescue. Competent personnel should assist the police and medical staff in rescuing the wounded, using local materials to stop bleeding, bandage and fix the wounded. When carrying the wounded, care should be taken to keep the patient with spinal injury in a horizontal position to prevent displacement and paraplegia.

5. Assistance. When the police are searching the scene to find out whether there are any unexploded explosives, you should help the police to maintain the scene and provide the police with clues such as suspicious persons and objects in a timely manner.

[Self-help in case of gas explosion at home]

When a gas explosion occurs, it can be handled according to the situation. If the gas tank or the outer body of the natural gas pipeline explodes due to gas leakage, the valve should be closed immediately and fire-fighting measures should be taken.

(Photo source: National Emergency Broadcasting Network)

If a tank or natural gas pipeline explodes, it is very dangerous and you should leave the scene immediately. If the explosion occurs in a neighbor's house, the neighbors downstairs can run downstairs, and if you are a resident upstairs, try not to pass by the door of the accident house and find other ways to leave. If there are no other ways, you can move to the upper floors first according to the situation and wait for rescue.

In addition, after an accident occurs, people should not be curious and watch, because it may hinder firefighters, medical staff and police officers from handling the accident scene. Secondly, after an accident occurs, buildings or other objects may become deformed or loose, and many uncertain factors are dangerous and easy to cause injuries.

How to help each other after the explosion

The damage caused by explosions is often collective. Before rescue workers arrive, we should help each other and minimize secondary damage as much as possible.

1. After an explosion occurs, the survivors should be organized to rescue themselves and each other immediately, and call 120, 110, 119 and other emergency and police stations for help.

2. Explosion accidents require coordinated rescue efforts from criminal investigation, medical emergency, firefighting and other departments. Before these personnel arrive, the scene should be protected and order maintained.

3. Check the injured person's injuries and quickly remove dust and sand from the injured person's trachea to prevent suffocation. If the injured person is unconscious, he should be placed on his side to keep his airway open. If breathing stops, artificial respiration and cardiac compression should be performed immediately.

4. Use local materials to stop bleeding, bandage and fix the injured. When transporting the injured, pay attention to keeping the patient with spinal injury in a horizontal position to prevent paraplegia due to displacement.

Keep safety knowledge in mind.

Handle gas accidents properly!

(Source: Xinhuanet, China Fire, Changsha Fire, Science and Technology Daily, National Emergency Broadcasting Network, Upstream News, Tencent News, Science Popularization China)