Foam fire extinguisher junior high school chemistry 5

To answer simply: 1. Isolate the accelerant (oxygen).

2. Lower the temperature below the ignition point of combustibles.

Teaching is now seriously out of touch with reality, and chemical foam fire extinguishers have been obsolete for many years.

Al3+ +3HCO3- == Al(OH)3(precipitate) +3CO2

Double hydrolysis of salts.

1 Dry ice and soda ash.

2 baking soda + acid.

I'm from the past, that's the correct answer.

1. Isolate oxygen.

2. Reduce the temperature.

Foam fire extinguisherIt is mainly suitable for extinguishing the initial fire of Class A substances such as wood, cotton, fabric, paper, etc. It can also be used to extinguish Class B substances such as gasoline, kerosene, vegetable oil and other initial disasters.

When a foam fire extinguisher is used to extinguish a fire, a large amount of carbon dioxide is ejected.

and foam, which can adhere to combustibles to isolate combustibles from the air and achieve the purpose of extinguishing fires.

Foam extinguishing agent.

It is divided into high-multiples foams and low-multiples foams. The foaming ratio of the high-multiples foam fire extinguishing agent is high (201-1000 times), which can quickly fill the fire space in a short time, especially suitable for large-space fires, and has the advantages of rapid fire extinguishing.

The low-multiples foam mainly relies on the foam to cover the surface of the fire object, isolate the air and extinguish the fire, and accompanied by water stains, it is powerless for the flowing fire, because there is water, if it is used to extinguish the live fire, then there is an electric shock and leakage disaster.

It can be used to extinguish Class A fires, such as wood, cotton, etc. misfires caused by the combustion of solid matter; It is most suitable for fighting Class B fires, such as gasoline, diesel and other liquid fires; It cannot extinguish fires of water-soluble flammable and flammable liquids (such as alcohols, esters, ethers, ketones and other substances) and Class E (electrified) fires.

It can be used to extinguish Class A fires, such as wood, cotton, etc. misfires caused by the combustion of solid matter; It is most suitable for fighting Class B fires, such as gasoline, diesel and other liquid fires; It cannot extinguish fires of water-soluble flammable and flammable liquids (such as alcohols, esters, ethers, ketones and other substances) and Class E (electrified) fires.

This type of fire extinguisher is a chemical reaction that mixes the acidic solution and the alkaline solution in the cylinder, and the generated foam is pressed out of the nozzle and sprayed out to extinguish the fire. In addition to being used to extinguish general solid matter fires, it can also extinguish combustible liquid fires such as oil, but it cannot extinguish fires caused by live equipment (except for the use of special nozzles) and organic solvents such as alcohols, ketones, esters, ethers and other alcohols (except for anti-solvent foam fire extinguishing agents). There are three types of foam fire extinguishers: MP type portable type, MPZ type portable boat type and MPT type cart type.

The functions of the foam fire extinguisher are:

When using foam fire extinguishers to extinguish fires, a large amount of carbon dioxide and foam can be sprayed, which can adhere to combustibles, isolate combustibles from the air, and achieve the purpose of extinguishing fires.

Scope of the fire:

1. Class A solid fires, such as wood, cotton and other solid substances; Class B substances such as gasoline, kerosene, vegetable oil, etc.

2. Class B fires, such as gasoline, diesel and other liquid fires (high-powered foam fire extinguishers).

3. Class E live equipment depends on the situation, if it is low-voltage electrical equipment, there is no problem, such as the computer system host room, general small equipment.

Foam extinguishing agents are divided into high multiple foam and low multiple foam. The foaming ratio of the high-multiples foam fire extinguishing agent is high (201-1000 times), which can quickly fill the fire space in a short time, especially suitable for large-space fires, and has the advantages of rapid fire extinguishing. The low-multiples foam mainly relies on the foam to cover the surface of the fire object, isolate the air and extinguish the fire, and accompanied by water stains, it is powerless for the flowing fire, because there is water, if it is used to extinguish the live fire, then there is an electric shock and leakage disaster.

Foam fire extinguishers are suitable for extinguishing the following types of fires: Solid fires: such as fires caused by combustible solid substances such as wood, paper, and cloth.

Liquid fires: such as fires caused by flammable liquids such as gasoline, diesel, paint, etc. Gas fire:

For example, fires caused by flammable gases such as natural gas and propane. The working principle of the foam fire extinguisher is to spray the foam on the fire source, forming a foam layer to isolate the contact between air and fuel, so as to achieve the purpose of extinguishing the fire. Therefore, foam fire extinguishers have a good fire extinguishing effect in extinguishing solid, liquid and gas fires.

However, foam fire extinguishers are not recommended for fires in high-voltage areas such as electrical equipment, as moisture in the foam may cause an electric current short circuit or electric shock. For such fires, carbon dioxide fire extinguishers or dry chemical fire extinguishers should be used.

1. It can be used to extinguish the initial fire of Class A substances such as wood, cotton, fabric, paper, etc.

2. It can also be used to extinguish initial fires of Class B substances such as gasoline, kerosene, vegetable oil, etc.

3. The anti-soluble foam fire extinguisher can extinguish the fire of polar solvents such as alcohol, ketones, lipids, aldehydes, ethers, etc.

Foam fire extinguishers are mainly used to extinguish: 1. Class A substances such as wood, cotton, fabric, paper, etc. 2. Initial fire of Class B substances such as gasoline, kerosene, vegetable oil, etc.; 3. Fire of polar solvents such as alcohols, ketones, lipids, aldehydes, ethers, etc. However, it should be noted that foam fire extinguishers are not suitable for some water-soluble and combustible fires and some flammable fires.

Dry powder fire extinguishers can extinguish solid fire, oil fire, gas fire and electric fire, and can spray directly at people. Foam fire extinguishers are mainly suitable for extinguishing oil fires, due to electrical conductivity, can not be used for electric fires, if it is a chemical foam, corrosive, can not be used for machinery and human body, and because it will be washed away, can not be used at the same time with water.

Applicable occasions: It is suitable for extinguishing the initial disaster of flammable liquids and gases, and can also extinguish the fire of live equipment. It is often used in laboratories, computer rooms, substations and distribution stations, as well as places with high requirements for the maintenance of precision electronic instruments, valuable equipment or items.

Fire extinguishing principle: When extinguishing a fire, a large amount of carbon dioxide and foam can be sprayed, which can adhere to the combustibles, so that the combustibles are isolated from the air to achieve the purpose of extinguishing the fire.

Scope of application: It can be used to extinguish fires caused by the burning of wood, cotton cloth, etc. Foam fire extinguisherThis type of fire extinguisher is a chemical reaction that mixes the acidic solution and the alkaline solution in the cylinder, and presses the generated foam out of the nozzle and sprays it out to extinguish the fire.

In addition to being used to extinguish general solid material fires, it can also extinguish fires of flammable liquids such as oil.

Chemical foam fire extinguishers are suitable for extinguishing fires from solid combustibles such as oil, wood, and cotton. Foam fire extinguisher, the principle of fire extinguishing is that when extinguishing the fire, a large amount of carbon dioxide and foam can be sprayed, and they can adhere to the combustibles, so that the combustibles are isolated from the air, so as to achieve the purpose of extinguishing the fire. The shell of the foam fire extinguisher is made of iron sheet, which contains a mixed solution of sodium bicarbonate and foaming agent, and a glass bottle liner containing an aqueous solution of aluminum sulfate.

When extinguishing a combustible liquid fire, if the chemical foam fire extinguisher has been burned in a flowing form, the foam will be sprayed from near to far so that the foam is completely covered on the combustion liquid surface; If it burns in the container, the foam should be shot at the inner wall of the container, so that the foam flows along the inner wall and gradually covers the ignition liquid level.

When extinguishing a solid material fire, a chemical foam fire extinguisher should aim the jet at the place where the burning is most violent. When extinguishing a fire, as the effective spray distance is shortened, the user should gradually approach the burning area and always spray foam on the burning material until it is extinguished. When in use, the fire extinguisher should always be kept upside down, otherwise the spray will be interrupted.

Foam fire extinguishers should be stored in a dry, cool, ventilated and convenient place, not close to high temperature or places that may be exposed to the sun to prevent carbonic acid decomposition and failure; In winter, anti-freezing measures should be taken to prevent freezing; And should imitate the frequent wiping of dust, dredge the nozzle, so that it remains unobstructed.

Chemical foam fire extinguishers are 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.

The air 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 and F fires, but cannot extinguish Class C, D and E fires.