Abstract: Based on the flux chamber test model developed by the United States Environmental Protection Agency, this study investigates the impact of several factors, such as expansion, foam thickness, and drainage time, on the sealing performance of synthetic foam extinguishing agents. The investigation is conducted under the production mode of compressed air foam. Additionally, the study compares and analyzes the sealing performance of compressed air foam and aspirated foam, aiming to elucidate the mechanisms that influence foam sealing performance. The results indicate that the foam stability of the synthetic foam extinguishing agent does not necessarily increase with expansion. It is found that the inhibition of the liquid film on oil vapor in the foam plays a crucial role in foam sealing performance. Specifically, lower foaming ratios result in higher liquid content in the foam, ultimately enhancing the sealing performance against oil vapor. Based on these findings, it is recommended to employ foam with a expansion of less than 10 for tackling 120# solvent oil leakage accidents. Furthermore, the study shows that, under the same expansion, compressed air foam exhibits superior stability, higher liquid content, and better sealing performance compared to aspirated foam.

Key words: expansion, foam thickness, flux chamber, explosion limit, compressed air foam