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New research confirms Cobra has a significant effect on incident heat radiation

In previous studies, it has been confirmed that coldcut™ cobra has a good ability to produce a mist consisting of very small water droplets in comparison to other alternative systems such as sprinkler systems or fog nail1. Research also shows that a mist with smaller droplets has a higher capability to absorb heat radiation2. No research has previously been done on Cobra's ability to absorb thermal radiation.

Why is the effect on incident heat radiation important?

Some Rescue Services already use Cobra to create a radiation shield, thus preventing the spread of the fire. An example is from a fire in a small community where the risk of fire spreading to another building was high. The rescue leader made the decision to use Cobra as a radiation shield between the two buildings. Cobra has a significantly lower water consumption than conventional methods, and in this way the water was sufficient until reinforcement arrived. The nearby building was saved in a situation where the spread of fire would normally take place.

In his Bachelor thesis from Luleå University of Technology 2018, Anton Johansson examines Cobra's ability to absorb heat radiation. The tests were conducted at RISE (Research Institutes of Sweden) in Borås and supervisor was Johan Biörsmark from Cold Cut Systems.

The results show that the water mist produced by Cobra has a significant effect on the incident radiation against an object located on the other side of the water mist. The effect varies depending on how much of the flames from the fire source the water mist covers. For operative use of Cobra, measurements made with HMF (Heat Flow Meter) are considered to be most useful. The approximate radiation level of the measurements made with HMF is about 50% of the original radiation level.

Measeurement of radiation absorption in the spray from the cutting extiguisher (in Swedish, summary in English) .pdf

1) M. Först, R. Ochoterena och J. Lindström, ”Spray characterization of the cuttingextinguisher,” 2012

2) M. Försth och K. Möller, ”Absorption of heat radiation in liquid droplets,” 2011