Maybe you want to know about the fire extinguishing principle of dry powder fire extinguishers

1. Chemical inhibition: interrupting the combustion chain reaction
The dry powder particles in the dry powder fire extinguisher decompose at high temperatures, releasing active ions (such as NH₂⁻, PO₄³⁻), which combine with free radicals (such as H⁺, OH⁻) generated during the combustion of objects to interrupt the chain reaction. Experimental data show that dry powder fire extinguishers can reduce the concentration of free radicals by more than 90%, significantly inhibiting the spread of flames. In addition, the metal ions (such as K⁺, Na⁺) in the dry powder act as catalysts to accelerate the free radical recombination reaction and greatly reduce the combustion reaction rate.

2. Isolation of oxygen: physical isolation of combustion aids
After spraying, dry powder forms a particle cloud with a diameter of about 10-50 microns, covering the surface of the burning object, forming a physical barrier, isolating the air, and the thickness of the covering layer is only 0.5mm to greatly reduce the oxygen concentration. At the same time, the chemical components in the dry powder decompose rapidly at high temperatures, while releasing a large amount of water vapor and other inert gases. These gases can effectively dilute the concentration of combustible gas and oxygen, thereby blocking the chain reaction of combustion and achieving a fire extinguishing effect. In addition, dry powder also has a good cooling effect and can effectively reduce the temperature of the burning object.

3. Cooling and cooling: absorbing heat to reduce the temperature
Dry powder particles undergo endothermic decomposition reactions at high temperatures to reduce the temperature of the combustion area. In addition, the surface of dry powder particles is rough, which can reflect part of the heat radiation and reduce the heat diffusion to the surrounding area. At the same time, the large amount of water vapor and other non-combustible gases released by dry powder particles during the decomposition process can dilute the oxygen concentration and effectively suppress the spread of flames.