So how does a rebreather work/ what does it do?

[EuphoriaII]

I browsed through a number of the threads but I don't get it. Does it recirculate the same air or what? Just curious

 

[jonnythan]

Very simply.. when you breathe, your body removes some O2 from the air and puts in some CO2. A rebreather takes CO2 out of the air you exhale, puts in a little more O2, then lets you breathe it again. That way, you can recycle most of the gas (nitrogen and sometimes helium) to make it last longer, among other things.

 

[EuphoriaII]

Thanks for the description. It makes sense to me now.

 

[H2Andy]

ayup... basically, the rebreather keeps the CO2 and O2 levels happy to keep you happy

there's two types, basically: closed circuit and semi-closed

semi-closed rebreathers expel some of the breathing gases as they work. a fully-closed
rebreather completely recirculates the breathing gases. but, both need to expel gases
as you acend to relieve pressure on the breathing loop as the gases expand.

semi-closed rebreathers are usually simpler and have a pre-set nitrox mixture or O2 percentage. the fully closed ones have oxygen sensors which constantly monitor the partial pressure of oxygen as it changes with depth and then based on this information add oxygen to the breathing mix as needed.

 

[MoonWrasse]

I believe they predate the modern open circuit scuba, go back over 100 years.

Here's a how it works for a closed circuit rebreather:

http://www.iantd.com/rebreather/rb.html

 

[H2Andy]

yup, strangely enough, the first "scuba" units were rebreathers.

but because of oxygen toxicity issues, they were only effective at relatively
shallow depths.

Henry Fleuss is credited with the first working rebreather, built in 1876

 

[caveseeker7]

I believe they predate the modern open circuit scuba, go back over 100 years.

That is correct, the Fleuss-Mask goes back to 1876 and is credited as the first rebreather for diving.

The first self-contained open-circuit scuaba system came from Frnez-Le Prieur in 1926, Gagnan and Cousteau's Aqualung demand regulatator came along in 1943.

The first elecronically controlled closed-circuit mixed gas rebreather hit the market in 1969, Walter Starck's Electrolung and Biomarine's CCR1000.

Dräger, who has been building rebreathers since the 1920 introduced the Atlantis I semi-closed circuit nitrox rebreather in 1995, the first rebreather for the consumer market.

 

[H2Andy]

well... Drager has been builidng rebreathers since 1907

 

[MoonWrasse]

yup, strangely enough, the first "scuba" units were rebreathers.

but because of oxygen toxicity issues, they were only effective at relatively
shallow depths.

Henry Fleuss is credited with the first working rebreather, built in 1876

And becuase of these problems, Jacques Cousteau was forced to develop the open circuit model around WW2. A little curiosity goes a long way

 

[caveseeker7]

well... Drager has been builidng rebreathers since 1907

I'm not as old as you, so I can't remember that far back.