How to cause an indoor fire?

Characteristics of residential fire, the main causes of fire are as follows:

First, fires caused by human factors.

Most of the family fires are caused by human factors. People's unsafe behavior is one of the most important factors leading to fire, such as unsafe use of fire, unsafe use of gas, littering cigarette butts, pulling wires in flammable ceilings, and installing lights indiscriminately. China's fire education and publicity started late, the foundation is weak, the investment is small, and the education and publicity target is wide, which makes the national fire awareness relatively weak. In particular, urban and rural residents have failed to master the correct knowledge and skills of fire control, lack the ability of self-prevention and self-rescue against disasters, and lack the concept of fire control law. This series of unfavorable factors directly led to the high fire accidents caused by human factors all the year round. According to the statistics of fire causes, the number of fires caused by human factors accounts for about 60% every year. According to the analysis of statistical data, man-made fires can be roughly divided into the following types:

(1) Careless use of fire in the kitchen. When using gas stoves and liquefied petroleum gas stoves, the pot is filled with water, and after heating, the water overflows to extinguish the flame, while the gas, liquefied petroleum gas and air released at ordinary times explode and burn when exposed to open flames; When cooking and refining at home, the oil pan overheated and caught fire; Dump the burnt straw ash, firewood ash, coal firewood ash, etc. Outdoor is casual, but the fire in these ashes is not completely extinguished. In case of windy weather, it is very likely that Mars will be brought to the haystack outdoors or the sawdust on the roof and ignited into a fire. This kind of fire is particularly prominent in rural areas.

(2) Careless use of fire for living and lighting. Urban and rural residents use mosquito killers or mosquito coils in summer, and fires are caused by improper placement of mosquito coils or long-term working conditions of electric mosquito coils; Some farmers are careless when lighting with candles during power failure, and forget to blow out the candles or light the candles too close to the combustible materials after the phone call, and the burning spreads into a disaster.

(3) Careless smoking. Littering cigarette butts at home, causing unlit cigarette butts to ignite combustible materials at home; Because you smoke on the bed or sofa after drinking or sleeping, you fall asleep before the smoke goes out, which causes the bedding and sofa to burn and cause a fire; Because some residents smoke when using inflammable and explosive materials at home, it causes fires.

(4) Children play with fire. Children lack life experience and don't know the danger of fire. Fire is a charming and magical thing for children, attracting curious children with a naive childlike innocence. The common ways for children to play with fire are: playing with matches and lighters at home, taking gunpowder out of firecrackers, and turning on the switch on gas and liquefied gas cylinders. Moreover, children usually play with fire when their parents are not at home. Once a fire breaks out, because children don't know how to put out the fire, they often panic and run away, hiding in the corner and so on. So that a small fire becomes a big fire and eventually leads to tragedy.

(5) arson. It is inevitable that people will quarrel when they are alive. If we can't tolerate each other, we will make enemies. At this time, some people who are ignorant, selfish, narrow-minded and lack of legal knowledge will set fire to vent their anger, resulting in family fire accidents, or set fire because mental patients have lost control of their illness.

Fire caused by electricity

In recent years, China's economy and power industry have developed rapidly, and the types and usage of electrical products have increased dramatically. However, due to people's unclear understanding of electrical circuits and electrical products, improper installation and operation, or poor quality of electrical equipment and electrical products, fire accidents have increased significantly.

(1) Fire caused by electrical lines. Electrical lines often cause electric sparks and arcs due to short circuit, overload operation, excessive contact resistance, leakage and other reasons, or cause overheating of insulated wires and cables, resulting in fires. 1 short circuit. Short circuit of household wires means that two wires of alternating current are in contact with each other, and the current does not pass through the electrical equipment in the line. Short circuit is one of the main causes of electrical fire, because when short circuit occurs, the current in the circuit backflow is very large, and strong electric sparks and arcs are generated at the short circuit point, which makes the conductor and insulation layer burn rapidly and causes the surrounding substances to burn.

2. overload. The amount of current that is allowed to pass through the circuit continuously without overheating the conductor is called allowable current carrying capacity or safe current. If the current passing through the conductor exceeds the safe current value, it is called conductor overload. The overload of the conductor leads to the temperature rise of the conductor, which leads to the burning of the insulation layer of the conductor, which can ignite the combustible materials near the conductor.

3. The contact resistance is too large. When conductors are connected, the resistance formed on the contact surface is called contact resistance. If the joint is handled well, the contact resistance will be small. If the connector is in poor contact or for other reasons, the contact resistance will be too high. When the current passes through, the place where the contact resistance is too large will produce a lot of heat, which will make the metal discolor or even melt, and cause the flammable substances near the electrical circuit to catch fire.

(2) Fire caused by electrical equipment. In addition to electrical wiring can cause fires, there are a large number of electrical fires caused by electrical equipment, because the use of electrical energy is mainly to convert electrical energy into heat energy, light energy, mechanical energy and so on. Therefore, it is inevitable to use some electrical equipment such as lamps, motors, electric heaters, etc. If these equipment and devices are not properly selected and used, it is very likely to cause a fire.

Characteristics of family fires

1, easy to form a large area of combustion. Fires in single-storey adjoining houses or dormitories in corridors, as well as fires in shanty towns, often lead to a fire in one family, affecting neighbors and causing a large-scale burning.

The fire spread rapidly. Due to the development of high-rise residential buildings into the air, vertical space and chimneys play an obvious role. Many "shafts" such as elevator shaft, stairwell, pipeline shaft and garbage shaft formed by vertical traffic will become the main way for the fire to spread vertically in case of fire, and the speed of vertical fire spread is 4-5 times faster than that of horizontal fire spread. Therefore, a fire in a high-rise residential building will easily spread into a human fire if it is not controlled in time.

3. Serious property losses. The residential area of residents is limited. In the limited space, there are a lot of household appliances, all kinds of furniture and clothes, and many flammable decorative materials. In the event of a fire, materials are not easy to evacuate and property losses are serious.