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Risk of elevator fire and preventive measures

Dec 14, 2018

With the rapid development of the city, the number of buildings is increasing, and the elevators are correspondingly increased. The elevators bring convenience to the upper and lower floors, and also bring about safety problems. Due to the special structure of the elevator itself, in the event of a disaster, especially an elevator fire, it is very likely to cause casualties. Based on the characteristics of elevator fires, the hazards of fires, etc., combined with the actual life, this paper analyzes the fire hazard of elevators and proposes targeted preventive measures. It is hoped that it will help to improve the safety performance of elevators.

Elevator fire; danger; preventive measures

With the rapid development of the national economy, elevator use has become an indispensable thing in life. While the elevator brings convenience to people's lives, it also brings people safety troubles. For example, on November 20, 1996, 39 people were killed and 81 injured in the elevator fire in Jiade Building in Hong Kong. On February 20, 2014, an elevator fire broke out in Century Flower City, Yuzhong District, Chongqing, causing two people to be trapped. Arrived to rescue and get out of trouble; on August 5, 2015, an elevator fire broke out in Xinyu Building, Yuexiu District, Guangzhou, causing five people to be trapped. Such examples are too numerous to mention. Because of the fire in the elevator, the space is limited, making it difficult for people to evacuate, and it is in a confined space. The air convection is poor, the temperature rises quickly, the smoke is large and it is easy to fill the entire space, which is easy to cause casualties. In order to prevent and reduce the fire hazard of elevators and take effective measures to prevent it, this paper has carried out a preliminary discussion.

First, the fire risk analysis of the elevator.

(1) The space is highly enclosed, and the smoke concentration is high after the fire, the temperature is high, and the spread is fast. The elevator has a small space, few outlets, good sealing and poor ventilation. Once a fire breaks out, combustibles generate a lot of smoke, spread from the fire at a speed of 1 meter per second, and quickly fill the entire space, showing a state of accumulation. , visibility is extremely low. The heat released by the combustion accumulates rapidly in the closed space, causing the temperature of the fire to rise sharply, the fire spreads faster, is difficult to control, and it is easy to cause direct damage to people or objects in the elevator.

(2) The special nature of the elevator structure makes it difficult to evacuate safely.

1. The elevator is difficult to stay directly at the safe evacuation exit location. First, because most of the elevators are in operation, when a fire occurs, it is difficult for the elevator to directly stay at the corresponding exit of the elevator floor. Second, when a fire occurs, the elevator usually loses power and the elevator stops, which makes it difficult to guarantee the elevator exit. Direct access to the safe exit outside the floor, which increases the risk of personnel.

2. The special structure of the elevator will increase the temperature and reduce the visibility. When the elevator is on fire, because there is no window, there is no special exhaust vent, the smoke will quickly diffuse the entire space, and the heat released by the combustion will quickly accumulate. The temperature can reach 800 °C or above, and the trapped people are prone to fear and panic. Evacuation is difficult.

3. Elevator fire, easy to generate toxic fumes such as CO. The top of the elevator is suspended by organic plastics. The combustion will produce a large amount of toxic and toxic gases such as CO. When the content of carbon monoxide reaches 0.5%, the fire temperature exceeds 43.3 °C, or the oxygen content in the air is less than 14-18%, It can be fatal, seriously affecting self-rescue and making evacuation more difficult.

(3) It is difficult to save.

First, the elevator is in operation. Once the fire occurs, the situation is difficult to find out, the command is difficult, and it is difficult to quickly and effectively deploy the fire.

Second, the elevator is in running state, it is difficult to grasp the stay floor, and the offensive route is difficult to be clear. The firefighters who attack inward conflict with the evacuated personnel and materials, which is not conducive to fire fighting.

Third, elevator shafts generally have poor drainage functions, so they cannot use a lot of water. Other fire extinguishing agents such as CO, 1211, dry powder, etc., are inconvenient to use due to harmful gases, and environmentally friendly green ideal fire extinguishing agents have not been widely used. It is extremely difficult.

Fourth, the elevator communication security measures are not fully popularized and the signals are unstable. It is easy for the communication equipment in the fire fighting to fail to function effectively, and the command is blocked.

Fifth, the hot air current is easy to cause casualties. In particular, the high-heat steam generated by the fire can reach 73 °C or above. Under certain pressure, it will be counter-attacked to the fire-fighting personnel, which increases the difficulty of fire extinguishing.

(4) Casualties and property losses.

The elevator is a highly concentrated place for people, logistics and business flow. In the event of a fire accident, due to difficulties in evacuation and saving, it is easy to cause serious consequences of mass death and serious property damage. For example, on November 20, 1996, 39 people were killed and 81 injured in the elevator fire in Jiade Building in Hong Kong. In 1999, a 16-story student apartment elevator fire broke out at Moscow University, Russia, killing three international students. The number of deaths, the great influence of society, and the deeper lessons are worthy of serious reflection and summary.

Second, the fire prevention measures of the elevator.

According to the fire hazard analysis of the elevator and the painful lessons from the fire in the elevator, the fire prevention of the elevator should be treated with both the symptoms and the root cause, and the fire protection design and fire safety management should be emphasized.

(1) Put a good source of safety and grasp the fire performance design.

1. Setup of elevator shafts and door openings. The elevator shaft should be set independently. It is strictly forbidden to lay flammable gas and ethylene-ethyl propylene liquid in the well. Cables and wires that are not related to the elevator should not be laid. The elevator shaft wall should not be opened except for the opening of the elevator door and ventilation holes. In the opening of the elevator door opening, the horizontal line of the bottom side should be slightly higher than the horizontal line of the ground outside the elevator car to prevent external water from entering the elevator shaft and causing fire.

2. Setup of the elevator room. There should be good ventilation in the elevator machine room to protect the motor equipment and cables from being damaged by dust, harmful gases and moisture as much as possible. Air conditioning equipment can also be installed to keep the ambient temperature at the optimum temperature, but it is not suitable to install hot water. Or heating equipment, because hot water or steam heating equipment is enough to pose a threat to the elevator, and even cause a fire.

3. Setting of the elevator car. First, a smoke-type fire alarm should be installed in the elevator car. If the front-floor indoor smoke-type fire alarm is activated, the floor call button should be invalid, and all elevators in the same group directly return to the designated On the floor, the elevator door opens and remains open. Second, the elevator car should be equipped with alarm devices that are easily recognized and touched by passengers, such as alarm bells, intercom systems, external telephones or the like. Third, permanent electrical lighting should be installed in the elevator car. Of course, there must be an emergency power supply, and the lighting power can be automatically turned on in the event of a normal power failure. Fourth, the elevator car should indicate the rated load or number of passengers in the elevator, and there should be an overloaded warning device. Fifth, ordinary elevators should be marked with the words “No driving when fire is on”. When a fire occurs, it is not safe to use ordinary elevators, because there are many reasons why the elevator doors cannot be opened or operated incorrectly. For example, fire makes elevator doors. The interlock device is damaged, powered off, etc. Of course, the most ideal safety elevator should ensure that the elevator car does not stop or open on the fire floor and can automatically return to the designated safety floor.

4. Fire elevator installations should also meet special safety requirements. First, the front room should be set up, and the front room setting should comply with the relevant provisions of the Code for Fire Protection of Building Design (GB 50016-2014); the second is that the load should not be less than 800kg; the third is the fire elevator shaft, the machine room and the adjacent elevator shaft. A fireproof partition wall with a fire endurance of not less than 2.00h shall be provided between the machine rooms, and a Class A fire door shall be used for the door on the partition wall.

5. The encryption function of the elevator is a new technology and new trend in the current elevator production. If a certain layer in the building is a silver bank, a book library, a confidential department, etc., it is not allowed to enter the heavy land of the general person. Only the person who presses the password can control the elevator. However, this new technology has drawbacks in fire fighting and rescue. If this is not allowed to enter the heavy fire, the fire elevator password becomes an offensive obstacle. Therefore, the encryption function of the elevator should obey and meet the fire rescue. Need, this should be taken seriously.

(2) Further strengthen the safety management of elevators and avoid risks of uncertainties.

As a special kind of equipment, in order to ensure the normal and reliable operation of the elevator and prevent the occurrence of elevator disasters, the elevators can only prevent or reduce disasters and improve their service level and service quality according to relevant safety regulations and strengthen safety management.

1. Safety requirements for interior decoration materials. The interior decoration materials of the elevators shall all be made of non-combustible materials, and flammable or flammable materials shall not be used.

2. Safety requirements for fuel storage and use. It is strictly forbidden to store and use liquefied petroleum oil or liquid with a temperature less than 60 °C in the elevator. Because liquefied petroleum oil and liquids with a burning point of less than 60 °C have a high risk of fire, once the liquid leaks and runs out of gas, it is easy to accumulate in the low-lying area of the room, and it is difficult to disperse and discharge, and the explosion concentration will be quickly reached and deflagration will occur.

3. The daily management of the elevator is also very important. Elevator should have daily inspection and regular inspection system, and establish and manage elevator technical files and original record files; smoking should be prohibited in elevator machine rooms and shafts; elevators in upper and lower elevators are not allowed to be used in elevators, or elevator buttons are arbitrarily pressed; elevators are strictly prohibited. Transport flammable and explosive materials, etc.

4. Seriously study business knowledge and constantly raise your own technical level. Elevator safety management personnel should master new technologies and new procedures, and be familiar with and implement the national policies and regulations related to elevators. In accordance with the actual situation of the unit, formulate corresponding management methods, continuously improve the management of elevators, and check and correct elevator use. Violation of the law.

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