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jim[_2_] jim[_2_] is offline
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First recorded activity by BoatBanter: Sep 2007
Posts: 4
Default Potable Water - The Third Way.



"N:dlzc D:aol T:com (dlzc)" wrote:

Dear Larry:

"Larry" wrote in message
...
dlzc wrote in news:1190415672.506271.93890
@k79g2000hse.googlegroups.com:

There are ship-board distiller units that use an
engine to pull a vacuum, and the engine's
waste heat to boil that water, to generate
drinking water. A little shorter...


http://en.wikipedia.org/wiki/Boiling_point

"The boiling point of water is 100 0C (212 0F) at
standard pressure. On top of Mount Everest the
pressure is about 260 mbar (26 kPa) so the
boiling point of water is 69 0C. (156.2 0F)."

AT 40' ASL, the boiling point must be down
to...to....211.95F!


What Brian left to the reader's imagination, is that the head
space of the tubes is at a near perfect vacuum, flooded only with
water vapor. You might recall that a perfect vacuum will lift a
column of water about 32 feet, on a high pressure day. Or had
you not figured that out?


Well no, he obviously hadn't figured that out. Nor can anybody figure
out what is going to hold a column of water 40 ft high as was stated in
the original post. The tubes may be 40 feet but the column of water will
be considerably less. How much less will depend on how much energy is
heating on the hot side and how much energy is cooling on the cool side.
The total amount of energy needed is not going to be any different than
any other distilling method.
Unless you have the free or cheap sources of cooling and heating at
specific temperatures this isn't going to work any better either.

-jim




David A. Smith


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