Små och storskaliga släckförsök med CAF och A-skum mot vätskebrand av bensin

The rescue service in Luleå took an initiative in 2014 and completed a try-out with CAF-system and A-foam against a liquid fire of kerosene. The use of the CAF system against liquid fires is in great interest because increased use of A-foam could lower the use of film-forming foams that contain harmful fluorinated substances. This would lead to positive effects on the environment.The try-out in 2014 was successful and indicated that CAF-system with A-foam was a good extinguisher. Luleå rescue service began planning more large-scale try-outs, this time against gasoline fires and this study is part of that project. The aim of this study has been to get an idea of the extinguishing capacity of CAF-system and A-Foam. A literature search showed that no tests similar to those envisaged in this project were documented. The empirical study consisted of 12 small- and 2 large-scale experiments. The liquid that were used in the experiment were gasoline. The small-scale experiment followed the SP-Method 2580 and the large-scale experiment where conducted in a 60 m2 large pit. A summary of the small-scale experiment shows that no control over the fire was obtained when the foam was applied by a direct deposition technique. The foam strikes in to the fuel too hard and the blanket of foam broke down faster than new foam was applied. It required a soft deposition technique to control the fire at the small-scale experiment. The first large-scale experiment failed when no correct foam quality was obtained during the try-out. The second try-out started with the use of a traditionally CAF nozzle, which produces wet heavy foam, and no control of the fire was obtained. The foam equipment had to be changed to a medium expansion nozzle before the fire could be controlled. With the medium expansion nozzle the fire was extinguished in about 5 minutes. More expanded foam, which results in smoother application, was needed to control the fire at the large-scale experiment. The application technique is important when extinguishing fires with CAF-system and A-foam. During both the small-scale experiment as well as the large-scale experiment re-ignition attempts were conducted. These re-ignition attempts indicated that A-foam has poor fire resistance. The foam blanket quickly broke down and the fire developed to full power again shortly after being exposed to an open flame. The conclusion of the study is that a CAF system and A-foam is capable of extinguish a petrol fire of about 60 m2 with a medium expansion nozzle and an application rate of about 2.8 l / (m2 ∙ min). Validerat; 20150924 (global_studentproject_submitter)