Desalinators

ken_vandeburgt

Paddler
Joined
Nov 13, 2007
Messages
1,154
I was wondering about distillation solutions. Dave Winkworth's article is a good read but suggests there is not one available on the markets ...

I wonder if it would be practical to build a solar still.
 

MartinZ

Paddler
Joined
Jun 17, 2007
Messages
197
Location
Bahia de Kino, Sonora, Mexico
Hi Ken,

I used a desalinator briefly a few years ago (this model). Very impressive but many non-field serviceable parts. For paddling in places where there's little water available I'd love to have one.

I've played with solar stills and they seem to take all day sitting undistributed to make a quart of water.
 

MartinZ

Paddler
Joined
Jun 17, 2007
Messages
197
Location
Bahia de Kino, Sonora, Mexico
I'm again thinking about purchasing a desalinator. I've heard that they can be purchased on EBay way below retail price but will need attention. Has anyone here purchased one this way? How hard was it to bring up to speed?

Martin
 

camshaft

Paddler
Joined
Jun 11, 2010
Messages
385
I just wanted to comment that katadyn customer service is well below par. And personally myself will never be purchasing anything made by them. So just the idea of spending 600-800 dollars on a katadyn product makes me ill


http://www.sciencebuddies.org/science-f ... p022.shtml


ken_vandeburgt said:
Does anyone have any experience with desalinators?

The Katadyn looks a bit slow ... one gallon per hour ... and costs a mint.

http://www.katadyn.com/en/katadyn-produ ... survivors/
 

Roy222

Paddler
Joined
Jun 2, 2009
Messages
405
A Desalinator can be a simple still.
Ideally, a still could be put together from your cook wear and a few extra parts. A long condensation tube could be stowed in a kayak. The longer the condensation tube the more water can be condensed. If your not going to make Moonshine a bump box will not be needed. Be careful, steam can burn.

Roy
 

KayDubbya

Paddler
Joined
Mar 22, 2008
Messages
339
Getting the salt out of sea water takes copious amounts of energy. There's no getting around it. Passive stills that use sunlight to condense water on a clear plastic film and drip back into a bucket can work but it's not practical for anything other than a true life or death survival situation. If you're planning on relying on seawater for an expedition, you'll probably want to set up several of them to collect any useful amount of water. Then pray that it's hot and sunny all day.

Katadyn's portable solution is one of the few that can be stowed in a kayaker's gear but I have no personal experience with their systems. I have spoken to a couple of retailers who sell them and they basically advised that they are an unnecessary luxury item for 99% of paddlers. If you're planning a trans-Atlantic crossing they may be a useful item to have, but you're going to need a second person just to pump the handle on the unit while you paddle.

For the price of 1 manual desalinator you could probably buy an EPIRB, several back-up batteries and lease a satellite phone. That would get you rescued faster than purifying a gallon of water through a manual desalinator.
 

MartinZ

Paddler
Joined
Jun 17, 2007
Messages
197
Location
Bahia de Kino, Sonora, Mexico
KayDubbya said:
I have spoken to a couple of retailers who sell them and they basically advised that they are an unnecessary luxury item for 99% of paddlers. If you're planning a trans-Atlantic crossing they may be a useful item to have, but you're going to need a second person just to pump the handle on the unit while you paddle.
I paddle mostly in the Sea of Cortez and have to carry all my water. On a 10 day trip, at 4 liters per day, that's 40 liters or four full droms. Along with 10 days worth of food, it can make for a fairly overloaded boat. The pumps I've tried didn't seem to require very much effort - the piston that builds up the necessary pressure is tiny. It seems like it could be done while sitting in a Crazy Creek Chair with a good book...
 

KayDubbya

Paddler
Joined
Mar 22, 2008
Messages
339
MartinZ said:
KayDubbya said:
I have spoken to a couple of retailers who sell them and they basically advised that they are an unnecessary luxury item for 99% of paddlers. If you're planning a trans-Atlantic crossing they may be a useful item to have, but you're going to need a second person just to pump the handle on the unit while you paddle.
I paddle mostly in the Sea of Cortez and have to carry all my water. On a 10 day trip, at 4 liters per day, that's 40 liters or four full droms. Along with 10 days worth of food, it can make for a fairly overloaded boat. The pumps I've tried didn't seem to require very much effort - the piston that builds up the necessary pressure is tiny. It seems like it could be done while sitting in a Crazy Creek Chair with a good book...
That's good to know. I suppose the advice I'd got was coming from the perspective of a Wet Coast paddler, where too little rain is rarely a problem...
 

ken_vandeburgt

Paddler
Joined
Nov 13, 2007
Messages
1,154
MartinZ said:
The pumps I've tried didn't seem to require very much effort - the piston that builds up the necessary pressure is tiny. It seems like it could be done while sitting in a Crazy Creek Chair with a good book...
That's an important point. I figured it would be like pumping a water filter, which is a good deal more effort than you are suggesting. The thought of doing that an hour a day is unpalatable.

Has anyone field experience with the katadyn desalinator pumps?

I note Gillet used one on his Hawaii sojorn but I wouldn't rely on anything he did as 'normal' experience.
 

Tootsall

Paddler
Joined
Oct 1, 2008
Messages
657
Location
Southern Alberta
I've never seen one so this is just a "shot in the dark" but I wonder if it wouldn't be possible to set one up so that it "pumps" while paddling...either through a cord attached to the paddle or possibly something linked to a foot brace. Just a bit of "blue sky" wondering...
 

MartinZ

Paddler
Joined
Jun 17, 2007
Messages
197
Location
Bahia de Kino, Sonora, Mexico
Tootsall said:
I've never seen one so this is just a "shot in the dark" but I wonder if it wouldn't be possible to set one up so that it "pumps" while paddling...either through a cord attached to the paddle or possibly something linked to a foot brace. Just a bit of "blue sky" wondering...
I met a couple of fellas in Baja a few years back who were trying to figure out how to do that. They had already given up on pumping while paddling - the swing arm needed more clearance than their cockpits allowed. However, they were experimenting with a system that allowed them to use their feet while seated on the sand. It was an early version and looked a bit rough, but worked ...
 

ken_vandeburgt

Paddler
Joined
Nov 13, 2007
Messages
1,154
I got interested in desalinators when I started gathering information about kayaking in Sea of Cortez off the Baja Peninsula.

The area is desert. My guide book has lots of pictures in which a paucity of trees and therefore driftwood, is evident. So a wood powered still wouldn't work very well.

But the thought of a still does bring on another idea ... does anyone know the vapour point of sea water in a partial or near vacuum?
 

JohnAbercrombie

Paddler
Joined
Dec 7, 2011
Messages
3,264
Location
Victoria, BC
newfie in Alberta said:
Not sure how well it would work to carry a small still, and a propane stove to fire it?
I think it would depend on how efficient your still was....

My 'back of envelope' calculation shows that it would take about 2.5MJ of energy to heat and boil a kg of water.
Propane contains about 50MJ/kg- I'd probably halve that to take the tank weight into consideration.

So, somewhere around 10% efficiency (not only in heating but also including vapour capture) would be the break-even point where you might as well carry water rather than propane.
10% doesn't sound very efficient, but even that might be difficult to attain under 'field conditions'.
Interesting question....
 

camshaft

Paddler
Joined
Jun 11, 2010
Messages
385
Interesting idea except for the huge bulk, but I guess in comparison hauling a crap load of water isn't light.



http://www.youtube.com/watch?v=TMCR-ie9H_w

Found it funny when they said, compact, lightweight,?
Height ....... 13 inches (Packed)
Diameter... 7.3 inches (Widest Point at Rim of Base)
Capacity.... 57.5 fl. oz.
Weight...... 2.67 lbs. 1211.09 grams
 
Top