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My country is in a struggle for water, along with its neighbors. Most of the country is along the Mediterranean sea coast. If instead of desalinating tons of water (the current plan) we could simply gather a lot of water vapor from the area close to the sea surface or maybe even on the beach, and move
this air in pipes uphill, to where the rain usually goes.
Pumping hot air in a pipe going up, should presumably be much easier than pumping water up, since the vapor is warm and would be pulling itself up. Perhaps you could paint the parts of the pipe in the hills - black, so solar power would assist, while the seaside part of the pipeline gets shaded, so it does not heat up - or maybe even submersed in the ground for part of the journey.
Once reaching their destination, the pipes would be cooled up there, probably naturally (higher up its always chillier) letting out the water where it would rain in nature, and filling the reservoirs with natural water, to be filled with minerals by mother earth on its way back out to the springs or wells where we get our usual drinking water, or to the near surface water, where the trees drink it, healthfully just as they drink rainwater.
Water Vapour Diagram
http://de.wikipedia...tamp=20051120170646
max. water per temperature [loonquawl, Mar 19 2009]
Solar Updraft Tower
http://en.wikipedia...Solar_updraft_tower
The easy, free energy method! [Skrewloose, Mar 20 2009]
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Steam is expensive, that's all I know. Otherwise, I applaud the ambitious goal. |
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You would net 100g water/cubic meter air if you could create a drop from 60°C to 20°C at the tube-terminus in the mountains.
Generating a breeze with 20km/h coming through tubes of a 10m^2 area (~3.5m diameter) would take 20.000 liters of water per hour up into the mountains, or 200cubic meters per 10(?) hours of daily operation. Wikipedia lists current big salination plants as producing ~500.000 cubic meters of water a day, at ~50cents per cubic meter, so your idea would have to be pretty inexpensive to compete. On the other hand, some tunnels made from flexible steel rods and black foil might do the trick, so [+] |
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Water is a thousand time denser than steam, and the partial pressure of water-vapor at the beach would mean you'd be pumping mostly air. So instead of having a two foot diameter pipeline, you'd need ductwork some hundred feet in diameter. Or more. Even then you'd just have a trickle of a flow rate unless you installed enormous fans. |
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The most efficient method of getting water from one place to another is clouds and rain. |
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I was about to suggest using the salt and osmosis to self-pump the seawater to the top while desalinating on the fly, when I saw similar ideas had been posted in the related links section above. |
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Also wondering if something could be done with humanzee's "long tall green house" idea... have a very long hydroponic tube of a range of different plants that live in water ranging from salty to fresh, and have the water vapour expelled by plants and microbes at each level be passed up to the next level. The lifting energy coming from the sunlight that feeds the liveware. Maybe some capillary action could help out here too? |
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Don't move the water to you, move you to the water. The shotcoming is that you may be living in a dessert in the near future and moving water about may be the least of your problems [Hows that daseva?] |
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Move to a country with more water. |
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Now, before its too late. |
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Tortoise, it's good to refer to the idea in your annotations. (please excuse the hypocrisy). I've always felt that it is ok to present alternative solutions to a problem, only after you've disseminated the shortcomings of the current solutions. Also, solutions should be creative and non... barbaric. Anyways, just a thought. |
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// So does this have to be made of steel or would it work if we had lots of really long, really huge conduits made of plastic film stretched over 150m high hoops. Like a very long, tall green house perhaps? // |
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Animals love to chew plastic/ fly into it. |
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so, [ldischler], should we encourage a more natural generation of water vapour from the sea, by placing sheets of black material just below the surface ? |
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Then, maybe we can encourage this vapour skywards, and up into the mountains, to form rain somehow ? Maybe the conduits would be too big. Maybe the existing wind is good enough. Or maybe some "reversible" wind turbines could be used on days with no wind (helps the evaporation of course). They can generate power on days that are too windy. |
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However, I feel we're getting into the area of major environmental impact. |
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Surely the easiest way to do this would be to have a solar updraft tower (see link), but piping the vapour up to the lakes? Paint the outside of the piping black to assist in keeping the steam warm over it's journey and you're sorted. |
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Sorry [8_9_tortoise], but moving won't help. I read on an official site of the Turkish water administration, that although it seems they have a lot of extra water, its only because most of the country does not use sewage and is not industrialized. They calculated that if even 70% of the country would use water in the way western Europe and the US use it, they would be in a vast shortage of water! Also, the neighboring countries need the water just as much, and if we share, maybe we could get the heat of the fight (you probably heard of it) down. (Somehow people are always angrier during the summertime). |
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Yes [HumanZ] that was basically the idea: some sort of greenhouse over the sea, and then pulling the vapor in pipes to cooler areas. |
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I disagree with [vaquitaTim], the hurricane tower idea to encourage clouding is quite old, but the pipeline idea could possibly be done with much less environmental impact. |
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Thanks [skrewloose] for the link! That's exactly the direction I was thinking of when I wrote "solar power would assist". |
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//so, [ldischler], should we encourage a more natural generation of water vapour from the sea, by placing sheets of black material just below the surface ?// |
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Even with a water temperature of 100F, the water vapor only amounts to 4% of the air by weight, so it's mostly air that needs to be moved. To fill an Olympic-sized swimming pool would take two billion cubic feet of air saturated with water at 100F, weighing 70 thousand tons. And actually twice that, because you can't get all the water out without chilling the air. |
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If you do this with a solar updraft tower, you could condense the water at great height and run it to the destination in pipes. There, the water would come down, generating electricity. So you not only have water for a cup of tea, you have the power to boil the water as well. |
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One might compress the steam to the density of water, using a huge nuclear power plant on the ocean. |
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Moving anything other than liquid water would need a high relative stupidity index. Partial pressures, phase latency (unless your pipes are heated, and even then), molar molecular mass, etc. |
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In short to move x cubic meters of water y meters up (or up and across) requires the same amount of energy regardless of the phase. The most efficient mechanism (as stated) is clouds. The most efficient method for humans is pumping liquid water. Now if you wanted to pump using specific gravity (specific densities) or capillary effects, I would have no arguments... |
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Imagine, if you will, a pipe filled with SF6. At 1.329 g/ml (liquid, 25 °C) it is more dense than water, and 1000+ times more dense than steam. Unfortunately the energy from steam might fuck it up a bit. But still, liquid water will rise above the SF6, although rather slowly. SF6 is not really miscable in water, although it might form an emulsion. There are ways around that with surfactants. So placing you water in at the bottom will give you water at the top with no energy besides that of injecting the water at the bottom under pressure. Works for petrol pipelines, and oil pipelines too.... |
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I thought of it further: The pipe at the sea end should float and be half emerged in water, (Its a halfbinvention no?) but anchored to its location in the sea. So every once in a while it gets submerged. The pipe at this section should also have some holes in it, so that when the waves come up, the water is sprayed in. Thus, at the pipe's sea side we may be pumping water, spray or air. As the pipe gets further away from the sea, the water will flatten, allow air through the pipe, and eventually drain back to the opening, while evaporating further. |
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Oh and [4whom]: People don't enjoy being called stupid, even if they are... (BTW does 4whom refer to the famous words: 2whom ya speain 2whom 2whome?, such noive, such noive, I neva hoid, ta whom ya speakin ta whom!) |
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"4% of air by weight" [ldish]... but wait! Since it is solar heated this "weight" is actually LIGHTER than the surrounding air (H2O as long as its not steam) is lighter than O2 and than CO2. So the surrounding air assists somewhat in pumping the water saturated air upwards to the maximum height near the location, and cooling the pipe near that location causes the vapor to condensate. So it still is plausible. |
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How much clear water do you get from desalination with osmosis, in a typical desalination factory? |
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//To fill an Olympic-sized swimming pool would take 56.5 million cubic meters of air.. weighing 70,000 tons...
How much does an Olympic sized swimming pool weight filled with with water? Or what's its size in cubic meters (or feet)? |
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// since the vapor is warm and would be pulling itself up // [pashute] |
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Not quite. Warmer gases rise because cooler gases are allowed to fall through/around and underneath them, pushing them upwards. Does a boat float without water? |
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Unless your pipe is wide enough to have internal weather - ie, flows of cool and warm air in opposite direction without significant mixing - you will need to introduce cool air at the base of the system, as does the solar updraft tower [link]ed by [Skrewloose]. Cool air rushing into the perimeter of the solar tower's surrounding greenhouse is what forces the warmed, lighter air to rise. |
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// The most efficient method of getting water from one place to another is clouds and rain. // [ldischler] |
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Efficient, yes. Precise, no. The targeting system clearly leaves something to be desired, else freshwater lakes would already abound in our preferred location. As long as you care not where - or indeed, if - that rain falls, the existing infrastructure is splendid. However, our aim here is to bring water to a currently dry place. |
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// [humanzee]'s "long tall green house" idea... // [gtoal] |
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It appears a most ingenious annotation - and possibly 'baker - has been lost. |
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I do seem to recall successful work along these lines on the coast of Israel being referenced elsewhere on the 'bakery, and I definitely recall seeing it on TV and/or the internet. Natural sea breezes blowing through open-ended greenhouses, vegetation capturing moisture from the air, then re-transpiring it to the far end, where it assisted further vegetation beyond the greenhouse. |
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// you may be living in a dessert // [eight_nine_tortoise] |
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Baked Alaska? Turkish Delight? |
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// I feel we're getting into the area of major environmental impact // [VaquitaTim] |
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I rather think that's the idea. |
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