Development of a Cup Burner Apparatus for Fire Suppression Evaluation of High-Expansion Foams

摘要

We developed a bench-scale high-expansion aqueous foam generator and integrated it into a traditional cup burner apparatus. Foam expansion ratios ranging from 50:1 to 590:1 could be achieved using air flow rates from 16 1/min to 38 1/min and liquid foam solution flow rates of 50 ml/min to 140 ml/min. The flow rates, foam expansion ratios, and cup burner flame extinction behavior with nitrogen provide a suitable bench-scale platform for controlled, systematic investigations of foam/flame interactions for a range of foam properties. Foams with an expansion ratio of 200:1 contain 81% water by mass. When evaporated completely, this amount of water should be insufficient to extinguish propane flames in oxidizer streams with 60% oxygen based on extinction of these flames by water mist. However, the 200:1 foam easily extinguishes a propane flame even in 100% oxygen.