Live fire tests on suppression of post-flashover fires using manually applied high and low pressure water sprays

摘要

Live fire/suppression tests were performed in a 12 x 5 x 2.5-m steel structure with a 2.5 x 1.1-m opening, using high and low pressure manually applied water sprays. The purpose was to compare a high-pressure (approx 40 bar pump pressure) fire-fighting system (pump, hose and nozzle) with a normal pressure (approx 10 bar pump pressure) fire fighting system, both systems mounted on a fire engine. Appropriate fire-fighting techniques, respectively, were also considered. One normal-pressure nozzle and two high-pressure nozzles where tested. The tests included water application using a manually oscillated nozzle from a fixed position within the room as well as using actual fire-fighting techniques, i.e. fire fighters advancing from the opening into the room while applying water in an oscillating pattern. The temperature was measured at 18 positions within the room and the total amount of water used as well as the water flow was recorded for each testozzle. Also the different techniques used in the tests were recorded. Conclusions from the tests were that high-pressure water sprays reduces the temperature more than low-pressure water sprays, especially when applying water oscillating from a fixed position within the room. When having fire fighters advancing through the room, high-pressure water sprays reduced the temperature faster but not significantly to a lower level than when using low-pressure water sprays. The tests also showed that high and low pressure water sprays require different techniques, which could have a dramatic effect on fire-fighting tactics as well as on the safety of fire-fighters. The tested high-pressure systems also have the advantage, in relation to low-pressure systems, in that they use a rigid hose mounted on a hose reel, which generally decreases the attack time, i.e. the time from arriving at the fire-scene until the time when it is possible to apply water on the fire.