How can we extinguish fire in cone roof tanks containing hydrocarbon fuels?

Answer 1

Inert gases work well if the container is sealed rather well, but many are not and the gases cannot build up enough for extinguishment. Actually, if you think about it, if it was sealed, the O2 would be depleted rather quickly and the fire would put itself out.

Foam systems work well in hydrocarbon storage tanks. Foam systems can even use subsurface injection to pump foam into the tank which quickly rises to the surface and spreads over the entire surface of the fuel creating a barrier from the oxygen and extingiushing the fire. Ansul is one of several manufacturers that have done a number of tank farms with these types of systems.

Check it out...
https://www.ansul.com/en/Products/foam_prod/foam_list.asp

They even have an example of a jet fuel tank farm.

National Foam and Viking also have equipement to do the job.

The following search showed some interesting results...

http://search.yahoo.com/search?p=foam+subsurface+injection&fr=yfp-t-501&toggle=1&cop=mss&ei=UTF-8

Good luck.

Answer 2

The only safe way is to have a connection (or connections) at the top where you can inject CO2, nitrogen or steam. this type of arrangement came be constructed so the injection can be made from a distance.