What fire safety knowledge do you have in summer?

It mainly includes: basic knowledge of fire, basic knowledge of fire extinguisher, first fire extinguishing method, knowledge of personnel evacuation and fire escape, and knowledge of fire extinguishing.

(A) the definition of combustion

Combustion, commonly known as fire, refers to the exothermic reaction between combustible and oxidant, usually accompanied by flame, luminescence and/or smoke.

Combustion has three characteristics, namely, chemical reaction, exotherm and luminescence.

(2) Combustion conditions

Necessary conditions for combustion —— The occurrence and development of material combustion process must meet the following three necessary conditions, namely, combustible, oxidant and temperature (ignition source). Only when these three conditions are met at the same time can combustion occur, and no matter which condition is lacking, combustion cannot occur. However, the above three conditions do not necessarily exist at the same time, and the combustion phenomenon will certainly occur. These three factors also need to interact.

1. Combustible: Any substance that can react with oxygen or other oxidants in the air is called combustible. Combustible substances can be divided into gas combustible substances, liquid combustible substances and solid combustible substances according to their physical states. Combustible substances are mostly compounds containing carbon and hydrogen. Some metals such as magnesium, aluminum and calcium can also burn under certain conditions, and many substances such as hydrazine and ozone can release light and heat through their own explanation at high temperature.

2. Oxidant: A substance that helps and supports the combustion of combustible substances, that is, a substance that can undergo an oxidation reaction with combustible substances is called an oxidant. The oxidant in the combustion process is mainly free oxygen in the air, and other oxidants such as fluorine and chlorine can also be used as oxidants in the combustion reaction.

3. Temperature (ignition source): refers to the energy source of combustion reaction between combustible substances and oxygen or combustion improver. Common is heat energy, as well as other heat energy converted from chemical energy, electric energy and mechanical energy.

4. Chain reaction: There is a chain reaction in flame combustion. When the fuel is heated, it will not only vaporize, but also the molecules of the fuel will decompose to produce free radicals. Free radical is a very active chemical form, which can react with other free radicals and molecules to keep the combustion going. This is a chain reaction of burning.

Sufficient conditions for combustion-(1) a certain combustible concentration; (2) certain oxygen content: (3) certain ignition energy; (4) Unrestricted chain reaction. For example, the minimum ignition energy of gasoline is 0.2raj, that of ether is 0. 19mJ, and that of methanol is 0.2 15mJ. For flameless combustion, the first three conditions exist and interact at the same time, and combustion will occur. For flame combustion, in addition to the above three conditions, there are unrestrained free radicals (free radicals) in the combustion process, forming a chain reaction, which is also one of the sufficient conditions for combustion.

(3) the type of combustion

Combustion is generally divided into four types according to its formation conditions and instantaneous characteristics: flash, fire, spontaneous combustion and explosion.

Flash burning is a burning phenomenon in which a substance can flash when it meets fire.

Fire is a phenomenon that combustible substances contact with the fire source in the air, and when they reach a certain temperature, they start to burn with flames, and they can continue to burn after the fire source is removed.

Spontaneous combustion is the combustion of combustible materials caused by heating or self-heating and heat accumulation without external sparks, flames and other fire sources.

Explosion is a phenomenon that the temperature and pressure rise or both rise due to the rapid oxidation or decomposition reaction of substances. Explosion can be divided into physical explosion, chemical explosion and nuclear explosion.

Physical explosion is an explosion caused by the rapid expansion of liquid or gas, and the pressure increases rapidly, which greatly exceeds the limit pressure of the container. Such as steam boilers; Liquefied gas cylinder explosion, etc.

Chemical explosion is an explosion caused by the chemical reaction of the substance itself, which produces a lot of gas and high temperature. Such as explosive explosion, explosion of combustible gas, liquid vapor, dust and air mixture, etc. Chemical explosion is the key to prevent explosion in fire fighting.

In addition to the direct contact of flame, heat usually spreads outward in three ways: heat conduction, heat radiation and heat convection.

(d) definition of fire

Fire refers to the disaster caused by burning out of control in time or space. Fire is mostly a social phenomenon, and the main causes of fire can be summarized into three aspects. One is man-made unsafe behavior (including arson); The second is the unsafe state of matter; The third is the defect of technology. And people's unsafe behavior is the most important factor.

(5) Classification of fire

According to the combustion characteristics of substances, fires can be divided into five categories: A, B, C, D and E.

Class A fire: refers to solid material fire. This kind of substance often has the nature of organic matter, and generally produces glowing embers when burning. Such as wood, coal, cotton, wool, hemp, paper and other fires.

Class B fire: refers to liquid fire and meltable solid fire. Such as gasoline, kerosene, diesel oil, crude oil, methanol, ethanol, asphalt, paraffin and other fires.

Class C fire: refers to gas fire. Such as gas, natural gas, methane, ethane, propane, hydrogen and other fires.

Class d fire: refers to metal fire. Such as potassium, sodium, magnesium, aluminum-magnesium alloy, etc.

Class E fire: refers to the fire of charged objects, precision instruments and other substances.

(6) Fire level

According to the National Regulations on Fire Statistics Management, fires are divided into major fires, major fires and general fires.

Extraordinary fire: in any of the following circumstances, it is an extraordinary fire with death 10 or more (including this number, the same below); Seriously injured more than 20 people; More than 20 people were killed or seriously injured; More than 50 families were affected; The direct property loss was 6,543,800 yuan+0,000 yuan.

Major fire: in any of the following circumstances, it is a major fire: more than 3 people died (including this number, the same below): seriously injured 10 or more people: dead or seriously injured 10 or more people; More than 30 households were affected: the direct property loss was more than 300,000 yuan.

General fire: A fire without the first two situations is a general fire.

(1) Types of fire extinguishers

There are many types of fire extinguishers, which can be divided into: portable and cart-type; According to the power source driving the extinguishing agent, it can be divided into gas cylinder type, pressure storage type and chemical reaction type.