Dry powder fire extinguishing agents are widely used due to their high efficiency in extinguishing fires and adaptability to the fire environment. The dry powder fire extinguishing agent mainly extinguishes fire through the physical and chemical effects of the powder mist sprayed under the action of the pressurized gas and the flame when it is in contact with the flame. The generated free radicals or active groups undergo chemical inhibition and side catalysis, which interrupts the combustion chain reaction and extinguishes fire. The second is that the dry powder falls on the surface of the combustible, chemically reacts, and forms a glassy coating under the action of high temperature, thereby isolating oxygen, and suffocating fire. In addition, there are some diluting oxygen and cooling effects.
Advantages and disadvantages of dry powder fire extinguishing: The main ingredient of dry powder fire extinguisher is sodium bicarbonate, which is "4102 baking soda" and 1653 diammonium hydrogen phosphate as the main raw materials. The suitable temperature of dry powder fire extinguisher is above -23℃. When it exceeds -23℃, it will not extinguish normally, be used or cannot be used at all. Although dry powder fire extinguishers can be used for Class A fires, they can only control the fire, but cannot extinguish the fire, so the ashes are easy to reignite.
The dry powder fire extinguisher sprays in powder form. After the spraying of the agent, the sight of the fire extinguisher is blocked, which seriously affects the breathing of the fire extinguisher and cannot be used normally. After the dry powder fire extinguishing agent is sprayed, the scene is in a mess. The sprayed material is difficult to clean up, and the economic loss caused is more serious. If the dry powder fire extinguisher vibrates for a long time, the agent is easy to harden and get damp and cannot be used.