Abstract: For the fire-fighting of liquid fires, the fire-fighting process often has the phenomenon of long fire-fighting time and repeated fire. The fundamental reason lies in the lack of in-depth study of foam on liquid fuel fire extinguishing process. The spread of foam on liquid surface is probably the most important factor to suppress the fire on liquid surface. It is of great significance to study the spread and coverage of foam extinguishing agent in the process of extinguishing fuel surface. In this paper, 3%AFFF, 3%AFFF/AR and 3%FP were selected to study the spreading performance of foam in rectangular channel.The results show that the spreading speed of 3% AFFF and 3% AFFF/AR is faster than that of 3% FP because the shear stress on the fuel surface is small. Because 3% AFFF and 3% AFFF/AR can form water film on the surface of solvent oil, their spreading speed is similar to that on the surface of water. 3% FP cannot form water film on the surface of solvent oil, which is slower to spread than that on the surface of water.

Key words: foam spread, firefighting, foam extinguishing agent, liquid fuel fire, fire extinguishing agent