Dry powder fire extinguishing agent is a dry and easily flowing fine powder for fire extinguishing. It is composed of a fine solid powder composed of inorganic salt with fire extinguishing efficiency and a small amount of additives by drying, grinding and mixing. It is a widely used extinguisher in fire fighting, and it is mainly used in fire extinguishers.
In addition to the special dry powder chemical extinguishing agent for extinguishing metal fires, dry powder extinguishing agent is generally divided into BC dry powder extinguishing agent and ABC dry powder. Such as sodium bicarbonate dry powder, modified sodium salt dry powder, potassium salt dry powder, ammonium dihydrogen phosphate dry powder, diammonium phosphate dry powder, phosphate dry powder and amino dry powder extinguisher, etc.
Dry powder extinguishing agent mainly extinguishes fire through the physical and chemical action when the powder spray ejected under the action of pressurized gas comes into contact with and mixes with the flame:
First, the volatile decomposition of inorganic salts in the dry powder and the free radicals or active groups produced by the fuel in the combustion process have chemical inhibition and by-catalysis, so that the chain reaction of combustion is interrupted and the fire is extinguished;
The other is that the powder of dry powder falls outside the surface of combustible, produce chemical reaction, and form a vitreous covering layer under the action of high temperature, thereby insulate oxygen, and then asphyxiate the fire. In addition, there are partial oxygen dilution and cooling effects.
