Chemical oxygen generator: Difference between revisions

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==Oxygen candle==

A chlorate candle, or an '''oxygen candle''', is a cylindrical chemical oxygen generator that contains a mix of [[sodium chlorate]] and [[iron]] powder, which when ignited [[smoldering|smolders]] at about {{convert|600|°C|°F|abbr=on|sigfig=2}}, producing [[sodium chloride]], [[iron oxide]], and oxygen at a fixed rate of about 6.5 man-hours per kilogram of the mixture. The mixture has an indefinite shelf life if stored properly: candles have been stored for 20 years without decreased oxygen output. [[Thermal decomposition]] releases the oxygen. The burning iron supplies the heat. The candle must be wrapped in [[thermal insulation]] to maintain the reaction temperature and to protect surrounding equipment. The key reaction is:<ref name=G&E>{{Greenwood&Earnshaw2nd}}</ref>

:2 NaClO₃ → 2 NaCl + 3 O₂

[[potassium chlorate|Potassium]] and [[lithium chlorate]], and [[sodium perchlorate|sodium]], [[potassium perchlorate|potassium]] and [[lithium perchlorate]]s can also be used in oxygen candles.

In the [[Vika oxygen generator]] used on some spacecraft, [[lithium perchlorate]] is the source of [[oxygen]]. At {{convert|400|°C|°F|abbr=on|sigfig=2}}, it releases 60% of its weightmass as [[oxygen]]:<ref>{{cite journal|title=Lithium Perchlorate Oxygen Candle. Pyrochemical Source of Pure Oxygen|author1=M. M. Markowitz |author2=D. A. Boryta |author3=Harvey Stewart Jr. |journal=Ind. Eng. Chem. Prod. Res. Dev.|year=1964|volume=3|issue=4|pages=321–330

|doi=10.1021/i360012a016}}</ref>

:LiClO₄ → LiCl + 2 O₂