Abstract:  In order to evaluate the technical feasibility of compressed air foam system for the rim seal fire of floating roof tanks, a series of full-scale fire extinguishing tests under different foam solution foam application rates and gas-liquid ratios were conducted to investigate the fire extinguishing performance of compressed air foam, and the suitable fire extinguishing application parameters were put forward.The results indicate that the rim seal fire for floating roof tanks was extinguished quickly and effectively by the rim seal discharge device of compressed air foam under the condition of the foam solution foam application rate being 3.4~8.0 L/(min·m²), and there was no re-ignition; the higher the foam solution foam application rateis, the faster the control and extinguishing speed is; the air/foam solution volume ratio has a slight effect on the fire control and extinguishing speed in the range of 8∶1 ~ 12∶1. It is suggested that the foam solution foam application rate is not less than 5 L/ (min·m²), the air/foam solution volume ratio is not less than 8∶1, and the apply duration of compressed air foam is no less than 15min in practical engineering.

Key words: floating roof tanks, rim seal fire, compressed air foam, fire extinguishing performance; foam extinguishing system