Paper Title
Study on Foam Drainage of Fluorinated Foam and Fluorine-Free Foamfire Extinguishing Technology

Abstract
The present study focuses on drainage property of fluorinated foam and fluorine-free foam. Fluorinated formulation concentrates is prepared based on the main components of fluorocarbon surfactant and hydrocarbon surfactant, and fluorine-free foam is prepared based on the main components of silicone surfactant and hydrocarbon surfactant. Compressed air foam is generated by an experimental apparatus established in this study. Particularly, an apparatus is also established based on the law of connected vessel in order to obtain the instantaneous mass of liquids drained from foams. The drainage features of the fluorinated foam and fluorine-free foam are analyzed and compared with each other. The results indicate that fluorinated foam drainage is definitely different from fluorine-free foam. The fluorinated foam shows a faster drainage and higher drainage rate. A sudden change is observed and used to characterize foam drainage property. The sudden change happened on the curve of drainage rate is denoted as the critical point of drainage (CPD). Surprisingly, no sudden change is observed in the curve of the fluorine-free foam drainage rate. Keywords - Foam Drainage, Fluorinated Foam, Fluorine-free Foam, Fire Extinguishing Agent.