Methodological studies for measuring foam effectiveness: suppression capability measuring the water equivalence of the isolation effect

Abstract

Introduction: It is well-known, aerial firefighting is a very expensive solution however bombing just pure water is not always enough to suppress the fires. In many cases special agents are added to water to increase its efficiency. Methods: This research used dried pine wood pieces as samples. Samples were divided into different groups: not treated samples for giving the reference data or treated samples to ensure data for calculating the isolation effect of foam. During the experiment a 3% foam solution was mixed. From this solution 6 – 9 – 12 expansion rate foams were generated. Samples were also provided with 2 – 5 mm high metal ring to ensure the exact depth of foam blanket. Each sample was put in a special heat oven which ensured the permanent 35 kWm-2 heat fluxes and measured the different ignition time. Results: Experiment demonstrated that the ignition times in case of foams are longer than in case of same equivalent pure water. It comes from the isolation effect of the foam, which can be expressed by the water equivalent up to 2.3 values.