BoatBanter.com - View Single Post - Potable Water

Mark Borgerson

In article ,
says...
On Sat, 22 Sep 2007 10:55:52 -0500, Brian Whatcott
wrote stuff
and I replied:

But what is the cheap source of getting the vacuum? I figured there
had to be a vacuum, although it was not said. But how do you get it?

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

SNIP

Simply put a one-way (out only) valve at the top where the two tubes
are joined. Pump water up both tubes to about 3" from the top,
displacing the air in the tubes. That will only require about
16 PSI from the pumps.

The major problem would seem to be that vigorous boiling is going
to carry over salt and contaminants from the boiling salt water unless
the tubes are large or there is some sort of debubbler on the
salt water side.

For heating and cooling, I suppose that you could use the sunny and
shady sides of a sailboat mast.

Mark Borgerson