01/04/2020
Compressed air foam extinguishes a crib fire

Compressed air foam extinguishes a crib fire

Source: BAM

Fire brigades all over the world face a broad range of operations. Fighting extensive fires is an essential and hazardous part of it. Due to the rapid progress of technical and chemical development, the general attention is focused on well-researched and effective extinguishing agents, to suppress hostile fires as quick as possible and to minimize the hazards for firefighters, population and environment.

For this reason, new special types of extinguishing media appear on the market from time to time in addition to conventional extinguishing media. Compressed Air Foam (CAF) belongs to the group of these special extinguishing agents. However, in order to be able to use the foam, special technical equipment and further training of the emergency services is required. As the current information on the extinguishing capacity of compressed air foam and its advantages and disadvantages over conventional extinguishing media is not clear, many fire brigades hesitate to accept the additional costs of the compressed air foam system.

In order to provide a conclusive and meaningful report on the extinguishing performance of CAF in comparison to conventional extinguishing media, the Bundesanstalt für Materialforschung und -prüfung carried out an extensive indoor test series with wood crib fires as part of the research project AERIUS (funded by Federal Ministry of Education and Research) in cooperation with the Berlin fire brigade, the Otto von Guericke University Magdeburg and the companies One Seven of Germany and Sthamer. This test series compares the examined extinguishing media under identical and reproducible conditions. Depending on their jet types, the cooling capabilities of the extinguishing media were recorded and compared with each other. With the help of the test results, a uniform overview of the extinguishing effect of water, water with a foaming agent, nozzle-aspirated foam, and dry as well as wet compressed air foam could be created.

The paper establishes a link between the extinguishing agents cooling capability and its wetting power by relating the results of extensive wood crib fire tests according to DIN EN 3 7 and findings of laboratory immersion tests according to DIN EN 1772. This comparison of the results of two different test series with the same test aspect is of particular importance, as it proves that laboratory results are also valid under real conditions.

Wood crib fire tests to evaluate the influence of extinguishing media and jet type on extinguishing performance at close range
Tim Rappsilber, Simone Krüger, Philipp Below
published in Fire Safety Journal, Vol. 106, pages 136-145, 2019,
BAM, Division Technical Properties of Polymeric Materials
and Division Constructive Fire and Explosion Safety for Gases