Jere Lull wrote in message ...
Larry wrote:

On Mon, 04 Aug 2003 05:02:15 GMT, Jere Lull wrote:



Is that 1200 watts over 24 hours? Or do you mean 1200 watt-hours?
Judging by how long it takes to boil a pot dry at home, I suspect the
prior, but even at 1200 watt-hours, that's somewhat over 100 AH per day
for merely 12 gallons. WAY expensive!



Yes... 1.2KWh/hour, about 10 cents per hour or 20 cents per gallon
from the power company.

Okay, taking that as a starting point, to get 12 gph (which is not
especially high output), the power requirements would be on the order of
30 KW/hr -- 2000+ amps at 12v; you'd want to go to higher voltages!
That's beyond most generators, or even primary power plants. Even our
home oil-fired furnace, rated for steam, might not be able to distill
THAT much water that quickly.

I've always wondered why there wasn't a distiller that ran off dry
stack heat, which would inundate the boat with fresh water, literally
for free on a cruising power boat with dry stacks. Navy distillers
make great water on ships.

Wouldn't work on our boat (20 HP Yanmar) or most engines I've seen up to
about 80 HP. In the few hours they run each day, there's just not that
much waste heat. The Navy isn't exactly known for efficient power
plants, and their ships are a bit bigger than what we cruise on.

I checked into the "evaporators" as they're called. They use engine
cooling water to distill seawater under vacuum. An electric motor/pump
generates the vacuum. It's not without faults however. The problem of
"carryover" in rough seas is always there. The electric motor is
pretty hefty (I forget exactly how hefty). There is a brochure at

http://www.beairdindustries.com/asse...rator_Book.pdf

I looked into the Maxim HJ3C which is the smallest at 2-8 GPH. The
price was *way* higher than RO, even without the other ancillary
equipment needed.

HV