What is the difference between foam fire extinguishers, dry chemical fire extinguishers and carbon d

Foam fire extinguisher: The fire extinguishing agent filled in this type of fire extinguisher is aluminum sulfate aqueous solution and sodium bicarbonate aqueous solution, and then an appropriate amount of protein foam liquid is added. If a small amount of fluorine surfactant is added, the fluidity of the foam can be enhanced and the fire extinguishing ability can be improved, so it is called a high-efficiency chemical foam fire extinguisher.

Air foam fire extinguishers: These fire extinguishers are filled with a mixture of air foam liquid and water. The foaming of air foam is generated by mixing the air foam mixture with air with the help of mechanical stirring, which is also called air mechanical foam.

There are many kinds of air foam fire extinguishing agents, such as protein foam, fluoroprotein foam, light water foam (also known as water film-forming foam), anti-solvent foam, polymer foam, etc. Because there are many varieties of air foam fire extinguishing agents, air foam fire extinguishers are distinguished according to the name of the filled air foam fire extinguishing agent, which is called protein foam fire extinguisher, light water foam fire extinguisher, anti-solvent foam fire extinguisher, etc.

Foam fire extinguisher: It can be used to extinguish Class A fires and some Class B fires, that is, ordinary solid matter fires and combustible liquid fires other than liquid water-soluble combustible and flammable substances such as alcohol, esters, ethers, ketones, etc.

Carbon dioxide fire extinguishers: These fire extinguishers are filled with liquefied carbon dioxide gas.

Carbon dioxide fire extinguisher: It can be used to extinguish Class A fires and electrical fires, that is, live material fires and fires of precision instruments and books and archives.

Dry chemical fire extinguisher: The fire extinguishing agent filled into this type of fire extinguisher is dry powder. There are many varieties of dry powder fire extinguishing agents, so fire extinguishers are called sodium bicarbonate dry powder fire extinguishers and ammonium phosphate dry powder fire extinguishers according to the names of different dry powder fire extinguishing agents filled inside. Amino dry powder fire extinguisher.

Dry powder fire extinguisher: used to extinguish Class A, Class B, Class C and electrical fires, that is, the initial disaster of solid substances and the fire of combustible liquid, gas or live equipment.

Class A fire: refers to a fire of solid matter. This substance tends to be organic in nature and can generally produce burning embers when burned. Such as wood, cotton, wool, hemp, paper fire, etc.

Category B fires: Liquid fires and meltable solid fires. Such as gasoline, kerosene, **, methanol, ethanol, asphalt, paraffin fire, etc.

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

Category D fire: refers to a metal fire. Such as potassium, sodium, magnesium, titanium, zirconium, lithium, aluminum-magnesium alloy fire, etc.

Electrical fires: This type of fire generally refers to the fire of electrical equipment and circuit fire.

Carbon dioxide fire extinguishers are generally used in precision instrument rooms. Nowadays, foam fire extinguishers are rarely used, and most of them are dry powder fire extinguishers. The types of fires they can extinguish are all Class A, Class B, and Class C, and in fact, there is not much essential difference.

Al2(SO4)3+6NaHCO3==3Na2SO4+2Al(OH)3 +6CO2 This is the principle of a foam fire extinguisher.

2NAHCO3 = = NA2CO3 + CO2 + H2O Principle of dry chemical fire extinguisher.

Liquid carbon dioxide fire extinguishers use the principle of carbon dioxide evaporation and heat absorption and carbon dioxide non-combustion.

One is liquid, one is powdery, and one is gaseous.

Scope of application for different types of fire extinguishers:

1. Dry powder fire extinguisher, it is suitable for extinguishing all kinds of flammable and combustible liquid fires, as well as electrical equipment fires.

2. The foam fire extinguisher is suitable for fighting general Class B fires, such as oil products, grease and other fires, and can also be applied to Class A fires, but cannot extinguish fires of water-soluble flammable and flammable liquids in Class B fires, such as alcohol, esters, ethers, ketones and other substance fires; It is also not possible to extinguish live equipment and Class C and D fires.

3. The carbon dioxide fire extinguisher is filled with pressurized liquefied carbon dioxide, which is mainly used to extinguish the initial disaster of Class A, B and C liquids (such as oil), combustible gas (such as gas) and live equipment.

First, the substances that are extinguished are not the same.

Dry powder fire extinguisher: suitable for extinguishing fires of petroleum products, paints and organic solvents. It inhibits the chain reaction of combustion and extinguishes the fire. It is also suitable for extinguishing liquid, gas, and electrical fires (dry powder has electrical insulation properties of more than 50,000 volts).

Carbon dioxide fire extinguishers: Carbon dioxide fire extinguishers use carbon dioxide gas stored in high-pressure gas cylinders as the fire extinguishing agent to extinguish fires.

Foam fire extinguisher: Foam can cover the surface of the combustible material and prevent air from entering. It is most suitable for fighting liquid fires, and cannot extinguish fires of water-soluble flammable and flammable liquids (such as alcohols, esters, ethers, ketones and other substances) and electrical fires.

Second, the material of the fire extinguisher is different.

Dry powder fire extinguisher: ammonium phosphate and other dry powder fire extinguishing agents.

Carbon dioxide fire extinguishers: Carbon dioxide fire extinguishers are carbon dioxide gas stored in high-pressure gas cylinders.

Foam fire extinguisher: a mixture of sodium bicarbonate and foaming agent, and a glass bottle liner containing an aqueous solution of aluminum sulfate.

Third, the principle of fire extinguishing is different.

Dry powder fire extinguisher: The dry powder fire extinguisher is filled with ammonium phosphate dry powder fire extinguishing agent. Dry powder fire extinguishing agent is a dry and easy-to-flow fine powder used for fire extinguishing, which is composed of inorganic salts with fire extinguishing effect and a small amount of additives that are dried, crushed and mixed into fine solid powder.

Carbon dioxide fire extinguisher: Liquid carbon dioxide is compressed in a small cylinder when pressurized, and then sprayed out when extinguishing the fire, which has the effect of cooling and isolating the air.

Foam fire extinguisher: When using foam fire extinguisher to extinguish fire, a large amount of foam can be sprayed, which can adhere to the combustibles, isolate the combustibles from the air, and at the same time reduce the temperature, destroy the combustion conditions, and achieve the purpose of extinguishing the fire.

Foam fire extinguishers are suitable for extinguishing general Class B fires, such as oil products, grease and other fires, and cannot extinguish live equipment;

Dry powder fire extinguishers are suitable for extinguishing initial disasters such as oil, combustible gas, and electrical equipment.

When using, first open the safety pin, hold the nozzle with one hand, aim at the fire source, and pull the pull ring with the other hand to extinguish the fire source.

Liquid carbon dioxide fire extinguishers have the characteristics of no moisture, no conduction, no damage to substances, no stains, etc., which are very suitable for extinguishing fires in electrical appliances, precision instruments, libraries, archives, etc. However, it cannot be used to extinguish fires of metals such as potassium, sodium, magnesium, etc., because these metals can chemically interact with carbon dioxide and increase the fire.

When using a CO2 fire extinguisher, your hand must be held on the wooden handle behind the spray canister and then activate the switch without touching the spray canister directly. Due to the low temperature of the spray can, you will get frostbite when you touch your hands.

The use of dry chemical fire extinguishers.

Fighting: general solid fire (a), combustible liquid (b), combustible gas (c) and the use of carbon dioxide fire extinguishers for live equipment.

Flammable and combustible liquids, combustible gases and low-voltage electrical equipment, instruments and meters, books and archives, handicrafts, displays, etc.

Uses of foam fire extinguishers:

General solid, and flammable liquid fires.

The scope of application of the three fire extinguishers:

Dry chemical fire extinguishers.

It is suitable for fighting general Class B fires, such as oil products, grease and other fires, and can also be applied to Class A fires, but cannot extinguish fires of water-soluble flammable and flammable liquids in Class B fires, such as alcohol, esters, ethers, ketones and other substance fires; It is also not possible to extinguish live equipment and Class C and D fires.

Foam fire extinguisher.

Basically the same as a chemical foam fire extinguisher. However, the anti-dissolution foam fire extinguisher can also extinguish the fire of water-soluble, flammable and combustible liquids, such as alcohol, ether, ketone and other solvents.

CO2 fire extinguisher.

When extinguishing a fire, it does not cause damage to items by leaving any traces, so it can be used to extinguish books, archives, valuable equipment, and precision instruments.

1. The concept is different.

The CO2 fire extinguisher is filled with 100% high-pressure CO2 gas; The fire extinguishing agent filled in the dry chemical fire extinguisher is dry powder.

2. The working principle is different.

The carbon dioxide fire extinguisher uses its own pressure to drive the gas out, and the carbon dioxide fire extinguishing agent has the effect of cooling and isolating the air;

Dry powder fire extinguisher relies on the volatile decomposition of inorganic salts in dry powder, chemical inhibition and negative catalytic effect with free radicals or active genes generated by fuel during combustion, so that the chain reaction of combustion is interrupted and the fire is extinguished.

3. The scope of use is different.

Carbon dioxide fire extinguishing agent is a clean gas, leaving no trace after extinguishing the fire, and is suitable for extinguishing equipment such as machine room, power distribution room, archive room, and valuable equipment (carbon dioxide fire extinguishers with metal casing cannot be used to extinguish electrical fires);

After the dry chemical fire extinguisher is extinguished, a large amount of powdery covering remains, which has a certain corrosive effect and dust pollution, and it is also difficult to clean. It is suitable for extinguishing general combustible solid fires, and can also extinguish fires caused by the combustion of oil and gas. It is suitable for oil fields, oil depots, refineries, chemical plants, chemical warehouses, ships, airports, industrial and mining enterprises, etc.

The biggest difference between high-pressure carbon dioxide and dry chemical fire extinguishers still depends on what protection area you are using, and the different scope of use of the two determines the type of fire extinguisher that needs to be prescribed.

In addition, some important protection areas are only equipped with portable fire extinguishers is not enough, but also need to set up automatic fire extinguishing systems, such as machine rooms, power distribution rooms, archives, spray paint, ultrasonic cleaning equipment, environmental protection filtration equipment and some countries must be equipped with fire extinguishing devices of enterprises and institutions, all need to go through a professional fire company to design the number of fire extinguishing devices in the protection area, installation location, etc. There is a Nianhai fire protection professional, you can ask.

First, the principle of fire extinguishing.

Dry chemical fire extinguishers.

First, the volatile decomposition of inorganic salts in dry minutes is chemically inhibited and negatively catalyzed by the free radicals or active genes produced by the fuel during the combustion process, so that the chain reaction of combustion is interrupted and the fire is extinguished. Second, the powder of dry powder falls outside the surface of combustibles. A chemical reaction occurs and a glass-like covering is formed under the action of high temperatures, which isolates oxygen and suffocates the fire.

In addition, there is a partial dilution of oxygen and cooling.

CO2 fire extinguisher.

When pressurized, the liquid carbon dioxide is compressed in a small bottle, and it is sprayed out when the fire is extinguished, which has the effect of cooling and isolating the air.

2. Scope of application.

Dry chemical fire extinguishers.

Dry powder fire extinguishers can extinguish general fires, and can also extinguish fires caused by the combustion of oil, gas, etc. It is mainly used to extinguish the initial fire of flammable liquids such as petroleum and organic solvents, combustible gases and electrical equipment.

CO2 fire extinguisher.

It is suitable for fighting Class B fires, such as kerosene, diesel, **, methanol, ethanol, asphalt, paraffin, etc. Suitable for fighting Class C fires (such as gas, natural gas, methane, ethane, propane, hydrogen, etc.). Extinguishing Class E fires (fires in which objects are charged and burned).

3. How to use:

Dry chemical fire extinguishers.

The most commonly used opening method for dry chemical fire extinguishers is the pressure handle method. After lifting the fire extinguisher to the appropriate position from the fire source, first turn it up and down several times to loosen the dry powder in the cylinder, and then let the nozzle be aimed at the most violent burning, pull out the safety pin, press down the pressure handle, and the fire extinguishing agent will be sprayed out to extinguish the fire. When turning on the dry powder fire extinguisher, hold the middle of the fire extinguisher with your left hand, aim the nozzle at the root of the flame, pull out the safety card with your right hand, rotate the opening knob, open the gas storage cylinder, and delay for 1-4 seconds.

The dry powder will be sprayed to extinguish the fire.

CO2 fire extinguisher.

The fire extinguisher should first be brought to the ** location, put down the fire extinguisher, pull out the safety pin, hold the handle at the root of the horn barrel with one hand, and hold the pressure handle of the opening and closing valve with the other hand. For carbon dioxide fire extinguishers without a jet hose, the horn tube should be turned 70-90 degrees. When using, do not directly grasp the outer wall of the horn barrel or the metal connecting pipe with your hands to prevent frostbite on your hands.

When using carbon dioxide fire extinguishers, if they are used outdoors, they should be sprayed in the upwind direction; If it is used in a narrow indoor space, the operator should leave quickly after extinguishing the fire to prevent suffocation.

According to its mode of movement, it can be divided into: portable type and cart type;

According to the fire extinguishing agent filled, it can be divided into: foam, dry powder, halide alkane, carbon dioxide, clean water, etc.

Types of fire extinguishers: and what to protect.

1. Carbon dioxide, carbon tetrachloride, 1211, difluorodibromomethane, 2402, 1301, heptafluoropropane, hexafluoropropane should be used for the rescue of cultural relics.

2. Dry powder, carbon dioxide, carbon tetrachloride, 1211, difluorodibromomethane, 1301, 2402, heptafluoropropane, hexafluoropropane, and anti-solvent foam should be used to extinguish flammable liquids.

3. Dry powder, carbon dioxide, carbon tetrachloride, 1211, difluorodibromomethane, 1301, 2402, heptafluoropropane, hexafluoropropane should be used to extinguish flammable gas.

4. Dry powder, carbon dioxide, carbon tetrachloride, 1211, difluorodibromomethane, 1301, 2402, heptafluoropropane, hexafluoropropane should be used for electrical equipment fire.

5. Carbon dioxide, carbon tetrachloride, 1211, difluorodibromomethane, 1301, 2402, heptafluoropropane, hexafluoropropane should be used for precision instrument fires