Full-scale fire tests of high-pressure water mist used as a fire barrier

The shielding capability of a high-pressure water mist curtain has been investigated.
An appropriate test setup for large-scale fire testing was developed, corresponding to applications for modern building types. A three storey concrete building at the Swedish Civil Contingencies Agency College in Revinge, Sweden was used for the tests. This building has proven to give reliable and repeatable test results.
The tests were conducted on a single floor in the building, consisting of three interconnected rooms. This is a multiple room design representative to a typical apartment configuration. A heptane pool fire of about 1200 kW was placed in the middle room (fire room) close to a door opening. A high-pressure water mist curtain protects the door opening to the adjacent target room. Fresh air could enter from both sides of the fire room. The temperatures and thermal radiation levels were measured in the target room at different heights. The surface temperatures in the target room was measured with a Forward-looking infrared (FLIR) camera.
A total of four tests were performed; one free burning test (test 0) and three tests (test 1-3) with 7.5, 10.5 and 11.9 L/min water pendent spraying in the door opening using micro nozzles of Danfoss type 1918, 1922 and 1934.
The room and surface temperatures as well as thermal radiation have shown that a high-pressure water mist curtain at 100 bar has sufficient attenuation effect to eliminate risk of fire spread. This would ensure a safe building design without having a fire tested door in the opening.
In addition, results have shown an extensive attenuation effect that can lower temperature and radiation levels to a point where human safety is ensured. This provides opportunities to design escape routes and similar using active fire separations.
Further, the test showed that it requires a minimum of approximately 10 L/min of water to fulfil the acceptance criteria for a 1.2 m wide door opening.