What are the three common fire extinguishers?

Three kinds of common fire extinguishers:

1. Dry powder fire extinguisher: Dry powder fire extinguisher is equipped with dry powder extinguishing agent. Dry powder fire extinguishing agent is composed of inorganic salts and a small amount of additives, which are dried, crushed and mixed into fine solid powder.

Blow dry powder (mainly containing sodium bicarbonate) with compressed carbon dioxide to extinguish the fire.

2. foam extinguisher: There are two containers in foam extinguisher, which are filled with two liquids, namely aluminum sulfate and sodium bicarbonate solution. The two solutions do not contact each other, and no chemical reaction occurs.

When foam extinguisher is needed, put the fire extinguisher upside down and mix the two solutions together, which will produce a lot of carbon dioxide gas.

3. Carbon dioxide fire extinguisher: Liquid carbon dioxide is stored in the bottle of the fire extinguisher. When working, press the handle of the bottle valve, and the carbon dioxide extinguishing agent inside will be sprayed from the siphon to the nozzle through the bottle valve, so that the oxygen concentration in the combustion zone will drop rapidly.

When carbon dioxide reaches a sufficient concentration, the flame will be extinguished due to lack of oxygen. At the same time, because liquid carbon dioxide will vaporize quickly, it will absorb a lot of heat in a short time, which will play a certain cooling role on the combustion products and help to put out the fire.