There are many types of fire extinguishers, which can be divided into portable and trolley types according to their mobile modes; According to the power source of driving fire extinguishing agent can be divided into: gas cylinder type, pressure storage type, chemical reaction type; According to the filled extinguishing agent can be divided into: foam, dry powder, halide, carbon dioxide, water, etc.

Principle: The dry powder extinguisher is filled with dry powder extinguishing agent. Dry powder extinguishing agent is a dry and easy to flow fine powder used for fire fighting, which is composed of inorganic salt with fire fighting efficiency and a small amount of additives by drying, grinding, mixing into fine solid powder. Using compressed carbon dioxide to blow out dry powder (mainly sodium bicarbonate) to extinguish fires.
Structure: Dry powder extinguisher uses carbon dioxide gas or nitrogen gas as power to spray out the dry powder inside the bottle. Dry powder is a kind of dry, easy to flow fine solid powder, which is composed of fire-fighting base and moisture-proof agent, flow accelerator, caking prevention agent and other additives.
Foam fire extinguisher
Principle: Inside the foam fire extinguisher are two containers, respectively holding two kinds of liquid, they are aluminum sulfate and sodium bicarbonate solution, the two solutions do not contact each other, do not have any chemical reaction. (Do not knock over the foam extinguisher at ordinary times.) When the foam extinguisher is needed, put the extinguisher upside down and mix the two solutions together to produce a large amount of carbon dioxide gas:

In addition to the two reactive agents, a number of foaming agents are added to the extinguisher. When the switch is turned on, foam is sprayed from the fire extinguisher, covering the burning items, isolating the burning material from the air, and reducing the temperature to extinguish the fire.
Structure: Acid and alkali fire extinguisher is composed of cylinder, cylinder cover, sulfuric acid bottle, nozzle, etc. The cylinder contains sodium bicarbonate aqueous solution and the sulfuric acid container contains concentrated sulfuric acid. The mouth of the bottle is sealed with a lead plug to prevent the concentrated sulfuric acid inside from absorbing water and diluting it or mixing it with the liquid medicine outside the bottle. The principle of acid and base fire extinguisher is to use the chemical reaction after the mixture of two agents, produce pressure to make the agent spray out, so as to extinguish the fire.

Principle: The liquid carbon dioxide is stored in the fire extinguisher bottle. When working, the pressure of the bottle valve is pressed down. The internal carbon dioxide extinguishing agent is emitted from the siphon through the bottle valve to the spray cylinder, so that the concentration of oxygen in the combustion zone rapidly decreases. When the carbon dioxide reaches enough concentration, the flame will be asphyxiated and extinguished. At the same time, the liquid carbon dioxide will quickly vaporize and absorb a lot of heat in a very short time, so it plays a certain cooling effect on the combustion and also helps to extinguish the fire. The cart type carbon dioxide fire extinguisher is mainly composed of the bottle body, the head assembly, the nozzle assembly, the frame assembly and so on. The fire extinguishing agent is liquid carbon dioxide fire extinguishing agent.
Structure: carbon dioxide fire extinguisher cylinder is made of high quality alloy steel by special process, the weight is 40% less than carbon steel. It is easy to operate, safe and reliable, easy to save, light and beautiful.
Application: It is suitable for fighting the initial fire of flammable liquid and gas, and also can fight the fire of live equipment. It is often used in laboratories, computer rooms, power distribution offices, and places with high maintenance requirements for precision electronic instruments, valuable equipment or items.
Water fire extinguisher

The extinguishing agent in a clean water extinguisher is clean water. Water has low viscosity, high thermal stability, high density and high surface tension at room temperature. It is an ancient and widely used natural fire extinguishing agent, which is easy to obtain and store.
It mainly relies on cooling and asphyxiation to fight fires. Since each kilogram of water is heated to boiling point from room temperature and completely evaporated, it can absorb 2,593.4 KJ of heat. Therefore, it uses its ability to absorb sensible heat and latent heat to play the role of cooling fire extinguishing, which is incomparable to other fire extinguishing agents. In addition, the volume of water vapor, which is inert gas, will expand by 1,700 times.
In extinguishing the fire, the water vapor generated by the water vaporization will occupy the space of the combustion area, dilute the oxygen content around the combustion, prevent fresh air from entering the combustion area, greatly reduce the oxygen concentration in the combustion area, so as to achieve the purpose of asphyxiation and fire extinguishing. When the water is in the form of spray mist, the specific surface area of the droplets and fog droplets will be greatly increased, which enhances the heat exchange between water and fire, thus enhancing its cooling and asphyxiation.
In addition, some flammable and flammable liquid soluble in water can also play a dilution role; The water mist produced by strong jet can emulsify flammable and flammable liquid, cooling liquid surface quickly and reducing the speed of combustible steam production to achieve the purpose of fire extinguishing.
Simple fire extinguisher
The simple fire extinguisher is a lightweight fire extinguisher developed in recent years. It is a small fire extinguisher with a filling capacity of less than 500 grams and a pressure of less than 0.8 mpa. It is disposable and cannot be refilled.
According to the type of fire extinguishing agent filled, simple fire extinguishers have 1211 fire extinguishers, also known as aerosol halide fire extinguishers; Simple dry powder fire extinguisher, also known as portable dry powder fire extinguisher; There are simple air foam fire extinguishers, also known as portable air foam fire extinguishers. Simple fire extinguisher suitable for home use, simple 1211 fire extinguisher and simple dry powder fire extinguisher can put out liquefied petroleum gas stove and cylinder upper corner valve, or gas stove and other initial fire, can also put out hot pot fire and waste paper basket and other solid combustibles burning fire. The simple air foam is suitable for the initial fire caused by oil POTS, kerosene stoves, oil lamps and candles, and can also put out the fire of solid combustibles.
Simple fire extinguisher is more suitable for standing home, easy to extinguish sudden fire situation.
Aerosol fire extinguisher
The application of aerosol in fire fighting engineering is derived from military technology. Aerosol fire extinguishing agent is used in some organic chemical agents, oil and other liquid storage tanks, as well as the explosion suppression system of military armored vehicles and tanks. Portable aerosol fire extinguisher is a new breakthrough in the field of fire extinguisher application. Combining the high efficiency gas producing aerosol agent with the fire extinguishing particle generator, the heat and power of the aerosol producing fire extinguishing gas can be used to decomposing the fire extinguishing particle generator agent and release the high efficiency fire extinguishing particle, which is superior to the traditional fire extinguisher in portability, safety and fire extinguishing ability.