How many kinds of fire extinguishers are there?
Foam extinguisherPrinciple: there are two containers in the foam extinguisher, which contain two kinds of liquid respectively. They are aluminium sulfate and sodium bicarbonate solution. The two solutions do not contact each other, and no chemical reaction occurs. When you need a foam extinguisher, put the extinguisher upside down and mix the two solutions together, which will produce a large amount of carbon dioxide gas.
Dry powder fire extinguisherPrinciple: dry powder extinguisher is filled with dry powder extinguishing agent. Dry powder extinguishing agent is a kind of dry and easy to flow micro powder used for fire extinguishing. It is composed of fine solid powder which is dried, crushed and mixed by inorganic salts and a small amount of additives with extinguishing effect. Use compressed carbon dioxide to blow out dry powder (mainly containing sodium bicarbonate) to put out the fire.
Carbon dioxide extinguisherPrinciple: carbon dioxide has a higher density, about 1.5 times the air. At normal pressure, liquid carbon dioxide vaporizes immediately, and liquid carbon dioxide, typically 1kg, produces about 0.5 cubic meters of gas. Therefore, when the fire, carbon dioxide gas can eliminate the air and surround the surface of the object or the distribution of combustion in a relatively closed space, reducing the fuel around or in the protection room oxygen concentration, produce suffocation and fire.
