Potable Water - The Third Way.

Angostura I can take or leave: India Pale Ale works for me, but not if I've gone for a Burton.

:-)

Brian W

Yes, true. You may not have to generate heat, but you still have to gather heat and this is not that efficient a set up for doing that. As the water evaporates the hot side cools a lot and more heat is needed to be added or the process slows down proportionately.

You could just as easily make a large flat pan and make a tent like structure of clear plastic and have the sun shine through the plastic and heat the pan of salt water causing evaporation. The water condenses on the plastic and runs down the sides where it is collected. this system doesn't have the vacuum but it does have the potential to collect a lot more sun light, which is actually far more critical to success. Or maybe you forgot to mention the large array of rotating mirrors directing the sun's energy on the hot side of the tube.

-jim

-jim

It isn't completely described. Flowing ambient temp water over the outside of the brine tube would be simple... seems like it might also provide some "cheap" cooling.

But we are *mechanical* engineers! Where are the pumps? ;>)

Not actually necessary either here in the desert, or in places where brine is available (except Salt Lake City in the winter). You can use the brine "pool" / ocean / sea as a heat source.

I see more difficulties in arranging cooling, so might have to use an applied heat source, and dump condensation heat to ambient. Which would require a slightly shorter column height, and higher boiling pressure.

David A. Smith

Joe

You haul it up without using any energy to do it? Absolutely not/ It will take a foot pound for each pound for each foot you haul it. No your basis for perpetual motion will not work. And is the opposite of brilliant.

Casady

Richard Casady brought forth on stone tablets:

Well, not quite. The harvested fresh water is actually buoyant in the sea water. Hauling up the water is energy free. Hauling up the container and the rope is not, however.

With suitable flotation, the container could be made neutral-buoyant, and so hauling it up could be free also, Finally, if the rope were HD polyethylene or something else with about 1.0 density, the rope could be free to hoist too. It would be necessary to attach a weight greater than the weight of water to be harvested to the container in order to get it to sink. This weight would then be disconnected/abandoned before hoisting the recovered water. From an energy standpoint, the investment would be that necessary to cover the friction in the hauling apparatus, and the the invested energy content of the abandoned weight (steel: high, concrete: medium, rock: free).

Venting the container to the surface would be impractical. Evacuate it instead.

With Wilbur, one must be careful to not discard the wheat with the chaff...

bob s/v Eolian Seattle

And how much of the time are you sailing in 500 ft deep water, which was the original specification?

Bruce in Bangkok (brucepaigeATgmailDOTcom)

snipped-for-privacy@gmail.com brought forth on stone tablets:

500 feet? That's only 83 fathoms. My sailing area is Puget Sound, much of which is 150 fathoms or more. Why? Is Thailand in a skinny water zone?

bob s/v Eolian Seattle

From Singapore north through either the Gulf of Thailand or up the west coats of Malaysia or most of the western part of Indonesia 150 ft. of water would be deep water. Wilbur's invention isn;t going to work very well over here.

Bruce in Bangkok (brucepaigeATgmailDOTcom)

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