Non-Electric Watermaker

[Canibul]

It almost sounds like trying to draw a line between having enough stuff onboard to be able to make enough water to survive in a long term crisis, vs. having the ability not to have to really worry about water, i.e. staying pretty much topped up.

[peterfynn]

As a new liveaboard-to-be with an unknown water maker aboard I have the following to offer. The pump on the Spectra is very clever as it recovers the energy in the high pressure reject brine inherent in an RO (reverse osmosis) system. Pressures required to get low TDS (total dissolved solids) water out of seawater (35,000 ppm TDS) in an RO system have to exceed about 350 to 400 psi. (Roughly 10 to 11 psi per thousand ppm). This is because the osmotic pressure of sea water is approximately 350 to 380 psi dependent on the TDS. You can only get product water once the feed water pressure exceeds the osmotic pressure of the water you are treating.
As dpex wants a non-electric system and the Spectra seems to only use power for the supply water at 150 psi or so, perhaps he should buy a Spectra system and try to use wind power to provide mechanical energy to a mechanical pump to get the 150 psi rather than making electrical energy (losses) to store (more losses) to then use to power an electric pump (more losses). Just an idea or suggestion and one I might try myself! No guarantee that it would work!
Looking at energy requirements for thermal desalination, I think you will find that the RO answer is the better way to go.
Peter

[dpex]

Check this out. http://www.westward-ii.com/PDF's/How...watermaker.pdf

I figure I can drive this system off my Old Thumper, single cylinder, 12Hp back-up diesel, to produce nearly 11,000 litres of water per year for a diesel cost of about 50 litres.

Given I am expanding diesel storage to 500ltrs, and rarely use my motor, I figure I will have a few years of water before I have to touch land again.

But even if I used my main motor to drive this system, (@2.5LPH) I'm still only up for 164 litres of diesel for 11,000 litres of fresh water.

Good Lord. I might be able to shower once a month. :--))

The explanations at the site noted above are wonderfully clear.

[Tellie]

Originally Posted by dpex

Check this out. http://www.westward-ii.com/PDF's/How...watermaker.pdf

I figure I can drive this system off my Old Thumper, single cylinder, 12Hp back-up diesel, to produce nearly 11,000 litres of water per year for a diesel cost of about 50 litres.

Given I am expanding diesel storage to 500ltrs, and rarely use my motor, I figure I will have a few years of water before I have to touch land again.

But even if I used my main motor to drive this system, (@2.5LPH) I'm still only up for 164 litres of diesel for 11,000 litres of fresh water.

Good Lord. I might be able to shower once a month. :--))



The explanations at the site noted above are wonderfully clear.

Careful, you might not be aware or you might have permission, but I believe these plans are covered under copyright. Leo might not appreciate them being posted here for free. I'd check with him.

[jheldatksuedu]

Originally Posted by Tellie

Careful, you might not be aware or you might have permission, but I believe these plans are covered under copyright. Leo might not appreciate them being posted here for free. I'd check with him.

He's not republishing, just providing a link, it's been published online already. You don't have to have permission to make one for your own use, you just can't sell it. This is also an area that I will be addressing sometime in the near future, having made note of the comments on waterlogs.

I expect I would do something like an outboard motor looking water driven high pressure seawater pump to an onboard watermaker RO unit.

I need to learn more about the waterlog pressure energy recover method mentioned on here.

Jon More about me at www.jheld.mysite.com

[osirissail]

Try eBay or other used marine parts suppliers for brand name units at huge discounts. You may have purchase new membrane and some parts but you will certainly save big money over buying new. New prices have more than tripled over the last decade due to the huge demand for the units. The most reliable of the 12VDC units is the Little Wonder and it has been "out there" for a very long time. See: VILLAGE MARINE LITTLE WONDER LWV145 WATERMAKER

[mite86403]

Hi, my name is John, from San Diego, CA USA. Currently own a 45 ft. Columbia, centre cockpit sloop. A couple years past I encountered a UK company, while searching internet, that developed a watermaker that one would tow while cruising. I saved the link, but doesnt seem to be active any longer. Seem to remember the name "Waterdog', & I dont mean the Portugeuse hunting dogs! Does anyone have info or contacts for this company?

[Astrid]

I think it was Waterlog:

Waterlog the only water-powered watermaker in the world

[barnakiel]

Make sure there are no big fish around ...

;-)
b.

[barnakiel]

BTW I have seen where they said you have to tow it pretty fast.

b.

[bstreep]

I would think a wind driven unit might be more practical. Not that it would be practical, just more so.

[islandplanet]

Maybe they were put out of business by the laws of physics?

[Dennis.G]

Cool log!

How about an exercise machine that makes water as another option:

[Wotname]

Originally Posted by Astrid

I think it was Waterlog:

Waterlog the only water-powered watermaker in the world

Looks impressive on this link. I wouls be interested to see how much the performance of the unit dropped off when boat drops off. Site indicates best speed is 6 kts but working OK at 5. How about 4 kts???

Obviously not much good at anchor but if it performs as advertised, it would be a consideration for the low electrical passage maker

[hummingway]

I have a katadyn 80e and it will run off my solar panels and produce about 3 gals per hour; which means I have to run it a lot. Being able to produce a few gals when transiting doesn't seem very useful in reality. Now if it would work off the tidal flow that would be a different story.