Re: Inert Gas In Fuel Tanks

From:         "David K. Cornutt" <cornutt@hiwaay.net>
Organization: Residential Engineering
Date:         18 Aug 96 20:13:38 
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Followups:    1
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In article <airliners.1996.1647@ohare.Chicago.COM> P. Wezeman,
pwezeman@blue.weeg.uiowa.edu writes:
>Inert gas is also used to pressurize
>the fuel tanks of liquid fuel rockets, since Goddard's time, when
>pressure is needed.

Hmmm... The Space Shuttle maintains tank pressure by circulating
back to the tank propellant that has been heated by the engine.
(In other words, hot hydrogen gas goes back the the hydrogen
tank, and hot oxygen gas goes back to the oxygen tank.)  Fire in
flight isn't really that much of a problem (unless the tank
ruptures), since, except for the first few seconds of flight,
there isn't any ambient air to support combustion.

Back in the late '60s, there were some auto racing groups that
experimented with buffering fuel tanks.  This was done in some
cases with inert gas, and in at least one case that I know of,
by buffering the fuel with an outer jacket filled with a fluid
that would (supposedly) make the fuel non-flammable if they
mixed.  Neither of these ideas worked very well in testing,
and as fuel cells improved, they turned out to be unnecessary.

---
David K. Cornutt, Residentially Engineered, Huntsville, AL
email: cornutt@hiwaay.net
I'm a rocket scientist.  Don't tell me what TV I must see.