It is the widely held belief that to put an already raging fire out the only thing that works is water.

While CO2, Nitrogen and Halon gases will starve a fire, they don’t reduce the heat. Even in enclosed environments where a fire has consumed all of the available oxygen and fades out leaving combustable gasses, once a firefighter opens the door a sudden rush of oxygen simply reignites the smouldering embers again, possibly with greater ferocity, as the materials on all surfaces in a room give off their own combustable gasses (pyrolisation) when reaching a certain temperature.

If an externally applied container could be used to mimic the enclosed environment, with oxygen expunging gasses pumped in to maintain the fire in a suppressed state, with a separate gas used as a carrier for a coolant to reduce the temperature, mimicking water?

What gas can be be used to cool a material so that fire cannot function, or gas used in tandem with a technique to steadily reduce temperature to avoid the harsh use of water to cool high temperatures?

Edited September 23, 20178 yr by Erina

Possible, yes: practical, no.

You would need to be able to supply enough cold gas for long enough to get the charred material to cool down.

If the building was sealed- like a bank vault- it would be much easier, but still difficult.

We're also utilizing a phase change to remove heat with water and to some extent with CO2(dry ice).

The problem is that water causes huge damage comparable to that of fire.

Like using a cloud of plasma as a carrier for electricity, there must be a simple method of flooding a room with gas (covering all exposed surface areas easily) and then changing its properties to cool down.

What data is available, or can be surmised, to cool down e.g. a table with the following properties:

Length: 21 5/8 "
Width: 21 5/8 "
Height: 17 3/4 "
Max. load: 55 lb

Table top: Particleboard, Fiberboard, Acrylic paint, ABS plastic, Paper
Leg: Particleboard, Fiberboard, Foil

ref: http://www.ikea.com/us/en/catalog/products/20011413/

 

This furniture is highly combustable, so how long would it take to cool this down in a 6ft x 6ft room with a fire that had taken alight the table's surface, it now producing considerable black smoke?

What kind of gas would be a good carrier, how would it be cooled and for how long would it take to all hot area, perhaps then to it's core if necessary?

"Controlled plasma" and "simple" are almost mutually exclusive.

A flame is already a weak plasma.

You could pump it full of heavier than air gas and then use standard AC.

Like John was saying earlier though, cost will be an issue.

There might be some endothermic reaction you could use. Not sure on that one though.

1 hour ago, Erina said:

The problem is that water causes huge damage comparable to that of fire.

 

It depends, on what you think is valuable? A sprinkler system saves lives rather than property.  

John Cuthber: I knew I'd get picked up on the plasma thing, clearly I don't know what I'm talking about, it just popped into my mind.

dimreepr: That was an issue that I consoled myself with by leaving the body hunt to the firemen (robot scouts), while the method I am looking to research solely focuses on putting fires out with minimal damage to non-human life i.e. physical goods.

7 hours ago, Erina said:

What kind of gas would be a good carrier, how would it be cooled and for how long would it take to all hot area, perhaps then to it's core if necessary?

Don't gases have a pretty low specific heat (almost by definition) and so you would have to continually pump in cold gas. And it would have to be oxygen free to avoid just fanning the flames. So vast quantities of chilled nitrogen or carbon dioxide constantly pumped into the area. In which case the anoxic conditions are probably more important than any cooling. And you have the problem of potentially suffocating the firefighters and any bystanders.

The best thing to do is go to an exit and put an exhaust fan. The fan will allow fire fighters to enter the building and fight the fire with much less water and put it out from the bottom instead of putting water on top of it... I used to work for DuPont, we had a fire brigade, it was part of a training program that sucking out or blowing in, the hot gases and following the fire to it's source with water will put it out far faster. 

 

https://en.wikipedia.org/wiki/Ventilation_(firefighting)