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Here’s how to bring fresh water to all of those arid places you keep hearing about on the news. This solution is simple and cheap enough that it could be built from parts from any hardware store and affordable in any country with a drought problem. Basically, you use the sun’s energy to both pump water from the sea and convert it into freshwater. It seems like most of the world’s water has salt in it, so we should use some of that.
Say you have a large otherwise useless plot of land, like the Sahara. By using the Thermosiphon principle you could pipe water from the ocean to the places that need it. Here’s how it works:
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Signing UpStep 1The general idea
Hot air rises, the same goes for all fluids, such as water. Given an extensively long pipe from the ocean to where ever needs water; you can coax that water to move through the pipe using heat. If your desert is at a higher elevation than sea level, by applying heat to a portion of the pipe, the water inside becomes less dense and elevates. The colder water prior to the heated portion of pipe, not wanting to create a vacuum, then rushes in to fill the pipe left by the heated water. So as long as you have heat, water moves up and through the pipe. (Just use check valves to prevent the water from descending at night.)
Hypothetically, you could pump seawater an infinite distance, given an infinitely long heat source. Next comes that infinitely long heat source cheap enough to drag across the entire Outback, which could be constructed from soda cans and glass panes.
Hypothetically, you could pump seawater an infinite distance, given an infinitely long heat source. Next comes that infinitely long heat source cheap enough to drag across the entire Outback, which could be constructed from soda cans and glass panes.
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the salt water alone would wreak havoc on the pipes, zinc would work out better, but maintenance would still be exhaustive and costly.
one break or leak in the line and you water source is gone at least until its fixed and flow is restored.
while it was a good thought, i don't think it would work out.
Try this: go to your sink, fill it up with water, next get a tube and dip one end in the water and have the other end go to the toilet or a bucket or something. Next, with the end thats going to the toilet or bucket, suck on it to create a vacuum force and then take your mouth of and have it point to the toilet or bucket. the water will keep going untll there's either nomore water or the tube is in air.
Sadly it will not lift water above the water surface by the method you propose.
(Any thoughts as to why no one has done this yet?)
L
The coffee maker works because the water in the bottom is boiled, the bubbles of steam rise up the tube with some water. The average density of the 2 is low so the steam lifts some water with it.
The diagram Postonic has drawn does not show the water at the bottom being heated at all.
The top of the pipe is open so no vacuum would be formed to lift the water out of the sea to continue the process.
If, in the pi;e, you had 2 non-return valves one below the point you heat and one above it then, if you cycle between heating and cooling the water between the 2 valves you would get a ( very ) small intermittent flow of water. The amount would equate to the difference between the volume of the water at the lower temperature and it's highest temperature less the difference in the volume of that bit of pipe at the 2 different temperatures. As far as I know it would not be easy to find some pipe which would allow this positive output.
As I said I really hope this is wrong.
As I asked before: "Any thoughts as to why no one has done this yet?"
L
And then the people at the other end of the pipe getting mad cause it's HOT water, and all they really wanted was a cold beer?
Other than this the irrigated areas would attract animals which humans will eventually try to exterminate.
The sahara is also an important source of nutrients for the rest of the planet. If you were to convert it into farmland the sand would not be blown around by the wind at such high levels and slowly starve other ecosystems worldwide.
Nature is a cruel and uncaring partner. Wild, unpredictable, and always trying to kill everything. 99% of species that existed are extinct, and pretty much all of that has nothing to do with humans (a few percent at most).
Infact, why not just use a nuclear reactor? Sea water could be boiled, creating clean water, powering generators, creating electricity. Even better, geo-thermal. Pump in pressurized salt water, it comes up hot and is allowed to expand, generators, clean water.... we are on the verge of being able to drill geothermal wells almost anywhere... why not to move water to the desert.
have you try to send your idea (concept) to someone highly placed in the "green party" of your country ? (sorry for my english, i'm french)
How about building a small scale model of this first and then take the lessons learned from this and apply it to a slightly bigger model. Repeat this procedure until you can be confident that your full scale design would work.
As far as contaminates, solar stills supposedly remove most contaminates. However, as cheaply as I plan on building this, contaminates will probably end my system and cause leaks.
The testing that you are describing is very dangerous.
Super heated / pressurized steam is nothing to mess around with. I would recommend taking a couple of classes in thermodynamics before even considering this experiment. I would also recommend some guidance from a person that is knowledgeable about pressure and steam. They would think of items that you probably have not even considered. It would be well worth the time and effort to consult an expert rather than getting a finger blown off or an eye blasted out.
Also read up on a pressure relief valve, This should be installed on any type of pressurized system.
You should also familiarize yourself with flash boiling.
http://en.wikipedia.org/wiki/Flash_boiling
L
L
Acres of desert in Saudi Arabia or the Outback are relatively cheap, as is this system, but combine both and the value would be much higher than either the land or the system by themselves.
Mark Twain "Buy land, they're not making it anymore."... fixed
First of the entire part of the pipe that goes across land would of course have to be black and maybe even have some mirrors directing sun onto the pipe to achieve maximum heat.
Furthermore the part in the ocean would have to be pretty far down to sufficiently cool.
Then I suppose some major calculations would be necessary to find the right size for holes on the land and sea end of the pipe to allow it to release some amount of water in the desert while using some of it to recycle more of the cold water up from the ocean end.
And to start the entire thing of I suppose you'd need some pretty big pumps to load the entire pipe with water the first time around...
I might be wrong but this is how I imagine it would have to be done.
How much will a mile of trough cost? 5250 feet of supports, reflectors, piping, glass/plastic...and upkeep for when the piping breaks or leaks or when bad weather hits it or someone wants to use the land under it for a road or steal some of it for scrap prices...considering that a desert is HUNDREDS of square miles and you would have to water a significant portion of it?
As Lemonie says, this is probably better as a forum topic, where you could discuss methods and technologies, maybe even get yourself sorted to produce a working prototype before publishing an actual Instructable.
If you could make it work, and you established your rights to the idea, you'd make a fortune!
Shame I don't have a small copper pipe to try the idea out with and see... :p