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Solar Desalinator (Making one-- DIY + Serious Engineering)


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#1 Michaelangelica

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Posted 11 March 2009 - 08:04 PM

Solar Desalinator (Making one-- DIY + Serious Engineering)


This is something I would like to invent.
It is a bit bold of me to start a thread in the Engineering Forums seeing my only tool in my "toolbox" is a Brazilian Screwdriver which does me for most jobs.
Plus a phillips-head screwdriver that I had to buy so I could open up, and put batteries into, my Sonic-Screwdriver (seriously! :hihi: )

The Solar Desalinator should be something terribly simple that can produce serious amounts of water say to fill a river with no energy inputs other than the structure/building and the sun.
The basic design seems straightforward enough. Ancient Greek sailing ships carried them.

Posted Image
This one is facing the wrong way. It obviously needs to be facing North.

What prompted me to start this thread was my daily sketching of designs (last night0 and coming across this article today

Opinions ___________________________________________
Concentrating solar powered desalination - a water solution?
Thursday, 12 March 2009
By Stewart Taggart


Australia needs electricity and Australia needs water. Concentrating solar power can help provide both.

Unlike solar photovoltaics, which creates electricity directly from sunlight, concentrating solar power first creates heat. This heat can then be used either to generate electricity or to desalinate water. Properly configured, concentrating solar power can switch back and forth from creating electricity to water.

Given these attributes, Concentrating solar powered desalination is a technology with hugely positive potential implications for global drinking water supplies. With futurists warning that water could emerge as a 21st Century flashpoint for strife, solar desalination is an avenue that should be explored aggressively.

Concentrating solar powered desalination - a water solution?(ScienceAlert)

Acquasol Infrastructure Limited | Home Page | Welcome

#2 Turtle

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Posted 12 March 2009 - 12:11 AM

The basic design seems straightforward enough. Ancient Greek sailing ships carried them.

Posted Image

This one is facing the wrong way. It obviously needs to be facing North.


:hihi: You Ozzarians and your d'unders upsidedownytudinalities. :hyper: North it is for you and so on to some other facts Jack. The reflective surface indicated in the diagram can be just be white paint; well laid on of course. :) The black absorbing pan is actually not necessary and probably mentioned because of a mis-understanding of what causes most of the evaporation when Sun strikes water. It is the photons striking water molecules on the surface that is the most active mechanism, not the temperature of the water. (somewhere I have an article on this in a global warming post*... :eek_big: :shrug: )

This desalinator setup in the diagram is also workable to treat gray water; sludge will develop in the pan rather than salt. (Prolly a salty sludge. :hyper:) I suggest making the angle of the dangle (technical term for the sloping top ;) ) the average of the highest and lowest angle of the Sun in your area over the period of a year. For me at about the 45th parallel North, the lowest angle is about 33º and the highest angle ~68º. 33+68=101:101/2=50.5. My dangle should angle ~50º. :cap:

*tray evaporation measure

#3 Michaelangelica

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Posted 12 March 2009 - 01:19 AM

:hihi: You Ozzarians and your d'unders upsidedownytudinalities. :shrug: North it is for you and so on to some other facts Jack

.
I thought that would get someone going.
Of course it is mere custom that N is the top of the map.
Just you wait till the magnetic poles reverse again then we will see who goes under and who is on top!!
Posted Image

It is the photons striking water molecules on the surface that is the most active mechanism, not the temperature of the water. (somewhere I have an article on this in a global warming post... :) :eek_big: )

That is something I did not know
So microwaves and what else would 'excite" water??.
A mirror surface would not help?
Would one - 100 of of these?
Posted Image

This desalinator set up in the diagram is also workable to treat gray water; sludge will develop in the pan rather than salt. (Prolly a salty sludge. :hyper:)

I have been wracking my brain to see if you could have a continuous channel of salt water, washing though one channel with collectors on either side. My old nursery igloo-hot- house gave me that idea. Unfortunately I can't draw for nuts.
This is not quite what I had in mind, but you may be able to see where i am coming from.
Posted Image
Posted Image
Seawater Greenhouse - Home Page
Seawater Greenhouse - Concept to Reality
some comments here
http://www.theenviro...ate-change.html

Do you 'get' this design? I don't.
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Solar Desalinator - Boat Design Forums
This one is a puzzle too. Far too complex.
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BTW
This ancient air water harvesting technique is amazing
Permaculture discussion forum • View topic - Air Water Harvesting
Wolf Klaphake: "Practical Methods for Condensation of Water from the Atmosphere" ~ Proc. Soc. of Chemical Industry of Victoria (Australia) 37: 1093-1103 (1936)

#4 Turtle

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Posted 12 March 2009 - 01:40 AM

I thought that would get someone going of course it is mere custom that N is the top of the map. Just you wait till the magnetic poles reverse agin then we will see who goes under!!


I'll se ya when I see ya. :eek_big: :hyper: :hyper:

It is the photons striking water molecules on the surface that is the most active mechanism, not the temperature of the water.

That is something i did not know.
So microwaves and what else would 'excite" water.
A mirror surface would not help?


For the simple device in the diagram, no; mirrors won't help. White paint. The microwaves and other more complex devices you show/mention would be boiling the water to get evaporation and this device does not boil the water or even depend on heating the water as implied by the "black liner". Again, it is photons striking water molecules that is responsible for the majority of evaporation in the device as well as evaporation from any open body of water.

I came back to correct my angle dangle calculation; the slope of the glass top should be at the lowest angle the Sun reaches in your area, not the average. Otherwise, some Sun gets blocked part of the year. :cap: For me, the top ought to slope 33º from horizontal so the Sun isn't blocked, and as the Sun gets higher it will simply shine through the glass more directly down on the water. :hihi: :shrug: :)

#5 Nitack

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Posted 27 March 2009 - 01:42 PM

These sorts of setups are perfect for making a solar still for parts of the world that don't have clean water. Question is can we make one that could make enough water to supply a person for a whole day and could we do it in a cost effective manner that would allow these to help alleviate the problem.

#6 Turtle

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Posted 27 March 2009 - 02:38 PM

These sorts of setups are perfect for making a solar still for parts of the world that don't have clean water. Question is can we make one that could make enough water to supply a person for a whole day and could we do it in a cost effective manner that would allow these to help alleviate the problem.


I'm planning to build a small one for experimentation. Course we know about best-laid-plans and all. :clue: I'm in the gedanken stage right now, trying to picture the problems before they happen and add some improvements. I have in mind a wooden frame with plastic sheeting stretched on for the top. My earlier musings on the angle of the top is in retrospect, babble. :evil: I think a 45 deg angle will admit Sun at all angles as long as the bottom edge is low to the tray, and I think it is an angle that best facilitates the water running down it to the collection trough. I also think that rather than a flat frame, it ought have some dihedral to move the flow away from the edges.

That's all da dap from dis tinkin' cap. :doh:

#7 Michaelangelica

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Posted 12 December 2009 - 02:22 AM

Video Collection - Small-scale solar water desalination

The DIY Desalination Unit Construction Manual
http://74.125.155.13...2&hl=en&ct=clnk

http://www.cms-uk.or...px?EntryId=1429.

#8 DFINITLYDISTRUBD

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Posted 24 February 2012 - 10:45 PM

I wonder how come nobody bothers with ultrasonic assisted distillation...seems to me that the same transducers that drive humidifiers would expedited the process....and could easily be powered by solar, wind or water (Ie. small generator driven by a stream).

Methinks vapours from the transducer fed through a vertical blackened copper pipe (via convection) (or better a row of multiple pipes heated by the sun) fed then into a collector followed by a trip into a second copper tube array buried a couple feet under earth then to a collector tank would yield a reasonable amount of water in a relatively short time. of course to reduce copper I would recommend adding limestone to the collection tank allowing the minerals to reduce the corrosiveness of the distilled water.

Edited by DFINITLYDISTRUBD, 24 February 2012 - 10:49 PM.