What is the principle of foam fire extinguishers?

[SanAdaline]

Foam fire extinguishers work on the principle of discharging a large amount of carbon dioxide and foam during firefighting. The foam adheres to combustible materials, isolating them from the air to achieve fire suppression. The functions of foam fire extinguishers include: 1. Heat absorption and cooling effect: The water released from the foam cools the surface of the burning material. 2. Oxygen isolation and suffocation effect: The foam forms a covering layer on the burning material's surface, isolating it from the air. Additionally, the water vapor produced by the heated and evaporated foam reduces the oxygen concentration near the burning material, contributing to suffocation-based fire suppression. 3. Radiant heat barrier effect: The foam layer prevents the heat from the combustion zone from acting on the surface of the burning material, thereby inhibiting the evaporation of the combustible material itself and nearby combustible materials.