Should you run up or down when a building is on fire?Don’t wait for the accident to happen and don’t know it

With the rapid development of urban architecture, there are more and more high-rise buildings in cities.

Most people work and live in buildings or high-rise buildings. Due to the large flow of people and different lifestyles, there will be many fire hazards.

A high-rise building in Dalian, Liaoning Province, the Kaixuan International Building, caught fire last year. The fire department dispatched 24 fire stations and nearly 400 firefighters. It took more than 7 hours to put out the fire in the Kaixuan International Building.

The fire is relentless. Once a high-rise building catches fire, the first reaction of many people is to run, but in a high-rise building, should you run up or down? Why is firefighting and rescue work so time-consuming and labor-intensive after a high-rise building fire?

Image source: Photographed by the author

Today is National Disaster Prevention and Mitigation Day (May 12). Pay attention to disaster prevention and mitigation, and protect the bottom line of life. I hope you will not use these first aid knowledge, but you must know it.

High-rise fire, why is it difficult to rescue?

Fires in high-rise buildings are generally caused by inadvertent use of fire/improper use of electricity, natural phenomena, arson, etc., in violation of safety regulations in production and life.

Why is it difficult to rescue a high-rise fire? Compared with ordinary low-rise building fires, high-rise building fires have the following characteristics:

1. The chimney effect increases oxygen circulation

The internal structure of high-rise buildings is relatively complex. Generally, there are multiple vertical shafts such as stairwells, elevator shafts, and exhaust ducts. These shafts have the characteristics of chimneys.

After a building fires, the hot air inside the building forms a density difference with the cold air outside the building, creating a pressure difference that forces the hot air inside the building to flow up the vertical ducts and then from the top of the building. Exhaust vents, etc.

At this time, a negative pressure area will be formed near the fire point, and the low-temperature and low-density fresh air outside the building is inhaled from the bottom of the building. Such air flow will bring more fresh air into the building, which is The chimney effect, the continuous influx of oxygen, fuels the fire.

The higher the height of a tall building, the more pronounced the chimney effect.

2. High winds and strong fires spread quickly

Tests conducted by the Shanghai Fire Bureau show that a building with a height of 100 meters catches fire, and the fire can spread from the vertical shaft from the bottom to the top floor within 30 seconds, and the entire building can instantly become a “three-dimensional fire field”. The wind speed can reach 15 m/s at the meter, and the higher the floor, the higher the wind speed, thereby accelerating the spread of the fire.

3. Restricted by the lifting of vehicles

At present, the height of domestic lift fire trucks is about 50 meters, and the lift of individual vehicles can reach 80 meters. The maximum operating height of lift fire trucks produced and used in the world is 110 meters, while the height of residential buildings and commercial buildings is generally The height is 3-4 meters, so the raised fire vehicles can generally only rescue the floors below 14 floors, and the fire rescue work on the higher floors will be limited.

4. The physical strength of firefighters is limited

When a fire breaks out, the electrical system shuts down or fails, and electrical equipment such as elevators cannot be used. Although trained firefighters can walk up to the 12th floor of the building or higher, firefighters also need to carry personal protective equipment and fire fighting equipment. Rescue equipment climbs stairs for rescue. These extra loads of at least 20 kg will greatly consume the physical strength of firefighters and reduce rescue efficiency.

5. Difficulty in evacuation of damaged and trapped people

According to estimates, when there are 120 people on each floor and there is only one evacuation staircase, in the event of a fire, it will take 19 minutes to evacuate everyone on the 15th floor to the ground, and 39 minutes for the 30th floor of the building. , the evacuation of the 50-story building took more than an hour, and in the actual situation of the fire, it took longer.

The most efficient and safe time to escape after a fire is 7 minutesso high-rise building fire escape is a great safety hazard.

Fire in a high-rise building, should you run up or down?

If you are in a high-rise building, how can you save yourself after a fire? Here are four escape tips:

When encountering a fire, keep calm, call fire alarm 119, explain the cause, location, and size of the fire, and at the same time, analyze the fire situation clearly and quickly escape from the safe passage.

Trapped persons below the 10th floor can immediately escape through the evacuation channel.

When the fire is not big, you can wet the bedding or blanket with water, wrap it around your body, cover your mouth and nose with a wet towel, and move forward by bending over to prevent the smoke from choking and reducing the risk of burning poisonous gas. Influence;

If the fire is very big, don’t blindly choose the way of jumping from the building because you are too excited, you must follow the principle of 7 meters jumping from the building——Don’t expect to escape by jumping from a building as long as it is higher than 7 meters.

Persons above the 10th floor, if the fire is not large, and the fire point is below their own location, they can first transfer to the roof, enter the building of the adjacent unit from the roof, and take the elevator to escape to the outside;

If the fire is large, do not escape through the corridor due to the “chimney effect”should find a safe, eye-catching balcony or window, waiting for firefighters to rescue.

Buildings over 100 meters generally have a refuge floor. After a fire, you can enter the refuge floor for evacuation. If all safe passages are cut off, the bathroom can also be used as a relatively safe shelter. In an emergency, the doors and windows of the bathroom can also be closed, the gaps can be blocked, all the faucets can be turned on, and if there is a bathtub, you can lie in the bathtub temporarily. Avoid danger and buy time for firefighters’ rescue.

How to prevent fire?

Since high-rise buildings are on fire, rescue is difficult, so preventing problems before they occur is the key reason. To take precautions against fires in high-rise buildings, you can start from the following points:

Strengthen the management of fire protection facilities in high-rise buildings, regularly test and overhaul automatic fire alarm systems, fire extinguishing systems, emergency broadcast systems and other linkage control equipment to ensure that high-level fire water tanks, fire pump outlet valves, and sprinkler systems are on pipes. Normally open.

Strengthen the fire safety management of the building to ensure that the evacuation passages and safety exits in the building are open at all times, and the normally closed fire doors should be closed.

Enhance fire safety awareness, avoid fire caused by inadvertent use of fire/improper use of electricity in violation of safety regulations in production and life, and improve the ability to deal with emergencies and fire self-rescue.

Strengthen the quality control of decoration materials, use non-combustible or flame-retardant materials for interior decoration of buildings, and avoid using materials that are flammable or flammable and that will produce toxic and harmful gases after combustion.

When traveling for business or tourism, the first thing to do when staying in a high-rise hotel is to look around and memorize the layout of the safety exits. If you have time, you can simulate the escape route once. In the event of an emergency such as a fire, you can quickly escape.

Hashtag: popular science escape fire