B dry powder The main ingredients of dry powder fire extinguishing agent (MF) are sodium bicarbonate and a small amount of moisture-proof agent such as magnesium stearate and talcum powder. With dry carbon dioxide or nitrogen as the driving force, the thousand powder from the container spray, the formation of powder spray to the combustion zone, dry powder in the decomposition of sodium bicarbonate by the action of high temperature, the chemical reaction equation is as follows:

2NaHC03 → Na2C03 ten H20 ten C02

The reaction is a heat-absorbing reaction, the reaction releases a large amount of carbon dioxide and water, the water is heated into a water vapor and absorb a lot of heat. Water vapor and absorb a lot of heat energy, play a certain role in cooling and dilution of combustible gases.

There are many types of dry powder fire extinguishing agents, which can be roughly divided into three categories:

Sodium bicarbonate (potassium) as the base material for dry powder, used to extinguish flammable liquids, gases, and electrically powered equipment fire;

Tri-ammonium phosphate, diammonium phosphate, diammonium phosphate, and its mixtures as the base material for the dry powder, used to extinguish flammable solids, flammable liquids, flammable gases, and electrically powered equipment fire;

The dry powder can also be used as the base material for the fire extinguishing agent.

Thousands of powder with sodium chloride, potassium chloride, barium chloride, sodium carbonate, etc. as the base material, used to extinguish light metal fires.

Some highly diffusible flammable gases, such as acetylene, hydrogen, dry powder injection is difficult to make the whole range of gas dilution, poor fire extinguishing effect. It is also not suitable for precision machinery, instruments, instrumentation fire, because there is residue after the fire.

In addition, in the use of dry powder fire, pay attention to timely cooling to avoid re-ignition.