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Old 3rd May 2014, 08:58
  #10411 (permalink)  
henra
 
Join Date: May 2010
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Originally Posted by Sheep Guts
( maybe 20 hours rather than 2hrs though).
Not really necessary.
These things burn intensely/violently for less than 10s. The remainder will stop to smolder and burn in not much more than a minute if at all. It's this first minute that counts.
The important and difficult thing is to relieve the pressure and fireball that builds instantly without letting the hot gases ignite surrounding material or blow up the container. It's a bit like Black Powder. You mustn't allow it to build up pressure in its containment. If within 1 minute nothing else started burning the danger is more or less over.

Regular Suppression Systems are extremely important in order to extinguish surrounding material that was ignited by a LiIon fire. The volume of packs of cells should be small enough that the violent Initial fire doesn't directly cause structural or flight control damage. And the distance between packs of cells needed be sufficient that no direct heat Transfer between the packs can take place that would ignite the next pack. Fire suppresion must be capable of extinguishing other material that is stored between the packs. Then, everything should be OK. Putting all the packs in one Container is a bad idea since it enables one run away pack to ignite others and thereby creating a very violent fire.
Edit:
Regarding relevance for MH370: Probably very low. Almost 3t (!!!) of LiIon in one Container would in all likelyhood have brought the plane down in a few minutes once ignited. Hardly conceivable that it would smolder for hours.
The Trouble with the freighters is that they don't have suppression Systems (Which I consider a big mistake). Which means that the battery fire may be over after much less than 5 minutes but by then other flammable material will have caught fire and keep burning. The hint is in the smoke in those instances. LiIons create very little smoke when burning. Copious amounts of smoke indicate that other stuff has caught fire.

Last edited by henra; 3rd May 2014 at 09:39.
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