On Mon, 11 Jul 2005 03:08:26 GMT,
Brian Whatcott wrote:
On Sun, 10 Jul 2005 18:32:24 -0700, Jim Richardson
wrote:

On Sun, 10 Jul 2005 20:47:35 -0400,
Larry wrote:
Keith Hughes wrote in
:

to 600-650 psig, and they still have leakage problems.


I love my distillers....
I love my distillers....
I love my distillers....
I love my distillers....
I love my distillers....



How much power does it take to make a gallon of fresh water from
seawater with your distillers?


Hmmm...let's pencil in the numbers on back of an envelope.

A (US) gallon of water is 8 lb that's 8/2.2 kg = 3.636kg = 3636 gm

From 20 degC, it takes 80 cal to get to BP then 540 cal/gm to get to
steam. Totals....3636 X (80 + 540) = 2.254 Mcal = 9.5 MJ

So if you could be happy with one gal/hr, it would take
9.5 MJ.hr or 9.5MJ / 60X 60 = 2.63 kilowatts.

But some or all those heating watts could maybe get returned to the
feedwater from the distilled water, and that's the trick to cutting
the power consumption of a still. Or how about a low vacuum process,
so the water feed boils at low temp?

Brian Whatcott Altus, OK


It was somewhat of a rhetorical question, but thanks for the numbers

As an aside, while pulling a vacuum will enable lower temp distillation,
I don't think you reduce your energy load any, just using a different
method, which may be easier to get, (mechanical, rather than electrical)


Distilation may make sense in large power boats, (read, 100' and up)
with plenty of waste heat, but it's not going to work well for small
sailboats. At some point, a distilation system would make more sense
than an RO system, but it's going to need a fairly large vessel for that.

And this ignores the issues of scaling in the boiler with salt water as
feed stock.


--
Jim Richardson http://www.eskimo.com/~warlock
Words fail me. Thank goodness I can make gestures.
-- Mark Hughes (in asr - 2001