Water Distiller

[Craig_B]

This next season my wife and I are planning on talking our boat from Canada down the ICW to the Bahamas for the winter.
One of many concerns I have is being able to carry enough water once in the Bahamas since we don't plan to spend much time at marinas,


I have a few different thoughts but one thing popped into my head the other day what about a small water distiller for those oops moments when we run out.


Found this on Amazon. https://www.amazon.ca/Distilling-Wat...%2C294&sr=8-14




Would this work to turn salt water into drinking water?


Thanks

[witzgall]

Nope, it will not remove the salt, you need a desalinator (Watermaker) for that.

Would be nice, though.

Chris

[Sailmonkey]

Originally Posted by witzgall

Nope, it will not remove the salt, you need a desalinator (Watermaker) for that.

Would be nice, though.

Chris

Actually a distiller will remove the salt, as the salt isn’t carried on the water vapor. Ships with requirements for large quantities of fresh water and a ton of waste heat available use evaporators for desalination. However this isn’t energy efficient on a small scale.

[HopCar]

I suspect it’s designed to remove minerals from tap water. My guess is that salt would quickly build up in it and it would need to be cleaned out often. If you try it let us know what happens.

Might be a good thing for cruisers that use a night snorkel, CPAP machine.

[a64pilot]

I had one almost exactly like that in the late 80’s sold by sears.
There was a little packet of activated carbon in the spout.
It works, slowly and takes a huge amount of electricity.
It would however as Hopcar suggests very quickly scale up with salt.

Think of the power required to boil into vapor every drop of water you drink, your not just boiling water, but having to boil it until it’s all turned to vapor.

[Sailmonkey]

Originally Posted by HopCar

I suspect it’s designed to remove minerals from tap water. My guess is that salt would quickly build up in it and it would need to be cleaned out often. If you try it let us know what happens.



Might be a good thing for cruisers that use a night snorkel, CPAP machine.

There is that massive downside....unless you like sea salt for your eggs.

[Craig_B]

Had not considered the salt build up.
However in a bad situation being able to make a litre of water in an hour doesn't seem to bad. It would help conserve a low or out water supply until you could reach somewhere with potable water.
Probably not worth the purchase for such minimal use unless you could find a way to flush the salt in the same way the membrane water makers do.
My understanding is those units require a big drain on eleticity as well. Needing a generator to power them.

[Sailmonkey]

Originally Posted by Craig_B

My understanding is those units require a big drain on eleticity as well. Needing a generator to power them.

Not at all. We have had a 1.5gph water maker that drew roughly 4 amps while running @12v.
We currently have a 9gph watermaker that draws roughly 10amps @ 12v.
No generator required.

[Matt Johnson]

Ignoring weight, you could fit 6 gallons within the storage space required for this distiller. It would take over 22 hours and 1375 amp hours to make this same amount of water... not a great trade.

Matt

[a64pilot]

Originally Posted by Craig_B

Had not considered the salt build up.
However in a bad situation being able to make a litre of water in an hour doesn't seem to bad. It would help conserve a low or out water supply until you could reach somewhere with potable water.
Probably not worth the purchase for such minimal use unless you could find a way to flush the salt in the same way the membrane water makers do.
My understanding is those units require a big drain on eleticity as well. Needing a generator to power them.

No, a Spectra is very energy efficient, but my little Honda can power my watermaker which is much less efficient than a Spectra and make about 35 gls an hour, which of course is a lot more than 1 liter an hour.

[Craig_B]

OK.

Sure sounds like a bad idea after all, lol


Thanks everyone for their assistance.

[thinwater]

Originally Posted by Craig_B

OK.

Sure sounds like a bad idea after all, lol


Thanks everyone for their assistance.

Yes, and at the same time, a resounding no.


The main problem is the heat source. If you Google stove top distilled water, you will find both commercial and DIY still that sit on a stove burner, no electricity required.

* You will need fuel, about 1 gallon per 7 gallons of water.
* All 316 SS. 305 won't last, based on lab experience with saline hot water baths.
* Yup, it will build up salt fast. You are probably best off to only cook each batch down about 70%.


It might be interesting to convert a tea kettle for really emergency use. But though I have built industrial scale distillation systems, I never explored this deeply. The niche seemed to small.

[jdtcanuck]

You could use a solar still to make pure water from seawater. Solar stills are found in some liferaft emergency kits. Probably not very useful for non-emergency situations because of the low production per day.

https://en.wikipedia.org/wiki/Solar_still

[witzgall]

I should have been more clear, while distillation will remove salts, this product won't do it in any meaningful way resulting in drinking quantities.

Chris

Originally Posted by Sailmonkey

Actually a distiller will remove the salt, as the salt isn’t carried on the water vapor. Ships with requirements for large quantities of fresh water and a ton of waste heat available use evaporators for desalination. However this isn’t energy efficient on a small scale.

[Pizzazz]

You can google water desalination to understand the trade-offs and difficulties in designing a small scale, efficient distiller. One way to remove the energy requirement is to take salt water from your engine heat exchanger (close to 180F), then use electric heat to go all the way up to 212F. This will reduce your energy consumption by 5/6ths or so. Still, you will have to deal with the scale build up, etc. There are some ideas also to use a vacuum pump to lower the boiling point of the water, then you can use water straight from the heat exchanger, without additional heating. I think it is doable but unlikely to be as efficient and practical as RO.