firespark
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Registered: 21-11-2012
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question about exothermic reaction and Nonflammable Ration Heater (NRH)
I was reading the other day about how military MRE's FRH was replaced with the new NRH and the site mention the new chemicals that were used but I can
not find the darn site again. when I do a search in google almost everything that comes up is about the FRH. The small amount of info that I was able
to find about the NRH was
Nonflammable Ration Heater (NRH): This small device, issued with most Western MRE-type meals, is designed for
individual heating of meal components in water. The device consists of a long plastic bag and two packets of chemicals. The
chemicals are poured into the bag, water added to the fill line, and the bag sealed. It is then placed into a container of water. The
device is able to heat all the applicable parts of an MRE to 140 degrees Fahrenheit in less than 15 minutes. The NRH is cheap,
produces no toxic fumes, and is very light. These devices were also available on the civilian market in Western countries starting in
1995. Weight: 0.06 kg; Price: $1 (V/S)
So my question is does anyone have any idea of the chemicals that are used in the NRH? I really hope you all can help because this is driving me nuts.
All I can remember is that it was something simple like lime and salt and blah blah blah. All I know is it was simple and nonhazardous. Any help you
all can provide would be awesome!
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Vargouille
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"The new NRH consists of anhydride powders..."
That's all I got. It could be calcium oxide, which releases heat when it forms calcium hydroxide, but the site also says that it's self-neutralizing,
which implies that there's also a solid acid in it.
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IrC
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This patent may be useful to study, as well check out all reference patents.
http://www.freepatentsonline.com/5517981.html
Also:
http://www.freepatentsonline.com/5117809.html
[Edited on 11-22-2012 by IrC]
"Science is the belief in the ignorance of the experts" Richard Feynman
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Mailinmypocket
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I haven't read up on it but i remember a friend of mine in the forces told me that the material used is zeolite...
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ScienceSquirrel
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Mood: Dogs are pets but cats are little furry humans with four feet and self determination! 
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It seems that several new technologies have been been developed, here is a nice poster that shows the original approach; magnesium, iron and salt with
water, and a new approach using zinc and air.
http://www.rbctx.com/Portals/95/26th%20ASC%20Poster%20-%20Ai...
This document has an evaluation of several new types including one that uses glycerine;
http://www.dtic.mil/dtic/tr/fulltext/u2/a397662.pdf
I suspect that the anhydride powder version is an improved version of the calcium oxide and water tin heater that uses something like calcium oxide
and phosphorous oxide that react to form calcium phosphate when moistened.
[Edited on 23-11-2012 by ScienceSquirrel]
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