Half a croissant, on a plate, with a sign in front of it saying '50c'
h a l f b a k e r y
Good ideas at the time.

idea: add, search, annotate, link, view, overview, recent, by name, random

meta: news, help, about, links, report a problem

account: browse anonymously, or get an account and write.



Fresh water for Africa

Use deep pipes for purifying sea water
  [vote for,

As you know, deep down below the surface of the planet is a very hot place.

My plan is to put a pipe far enough into the earth so sea water that is passed through the pipe is boiled.

It comes back up again through a parallel pipe as steam. (before you think it .. yes I know people already use this method for creating electricity (very environmentally friendly)).

The steam that comes up could easily be condensed back into - now pure - drinking water. All the rest of the stuff (Salt etc) will be dumped back into the sea. Lots of nice fresh water for people that really need it.

britboy, Mar 25 2004

(?) Geothermal Energy http://www.nrel.gov...geoelectricity.html
Flash boiling of geothermally heated water [suctionpad, Oct 04 2004, last modified Oct 21 2004]

(?) THERMIE Project http://europa.eu.in...ibrary/geotherm.pdf
About half-way down there is a para on geothermal [suctionpad, Oct 04 2004, last modified Oct 21 2004]

(?) Global Water Usage http://www.ifpri.or...dia/water_facts.htm
Global water usage [suctionpad, Oct 04 2004, last modified Oct 21 2004]

(?) Deep Hole Digger/Water Finder http://www.geocitie...heliumjpgindex.html
I knew the motorhome I invented when I was 11 would some day be required when technology caught up with my vision! [Helium, Oct 04 2004, last modified Oct 21 2004]


       a) What Tabs said.
b) Why Africa? Looks to me like it's California that really needs the stuff.
DrCurry, Mar 25 2004

       Every now and again you send a huge metal 'bendy' cleaning pole right down the pipe (and up the other side) -- which shoves all the salt up the other pipe and out of the top. Just like someone might put a stick down a blocked drain and 'unclog' it.
britboy, Mar 25 2004

       Erm, no [britboy] you couldn't send a big bendy cleaning pole down that far. Standard practice for pipe inspection and cleaning would be a "pig", an autonomous or semi-autonomous device which fits inside the pipe (see the James Bond film "The World Is Not Enough" for an albeit fanciful example).   

       I have to say the process of flash distillation should be a possibility, using geothermal energy as the driving force. This is the approach taken by most geothermal energy plants (see [link]). As long as you maintain a high enough pressure through all of the pipe the water remains liquid and you should be able to minimise salt encrustation. Once on the surface the pressure is reduced and the water boils.   

       I can see problems with bacterial growth in the pipe making the water unusable. This is an extremely difficult problem encountered in oil wells, where bacteria produce highly toxic hydrogen sulphide gas.
suctionpad, Mar 25 2004

       Having done a bit more Googling, there are people working on this now (see second [link]) as part of the THERMIE project.   

       [Toadinnov] has something of a point. If we take current world geothermal energy production, it should provide enough energy to produce nearly 450 million tonnes* of fresh water (plus the water produced could be used for electricity generation). In the US water production would be 170 million tonnes. Total world usage of water ([link] number three) in 1995 was estimated at 1799 cubic kilometers (one thousand million tonnes of water per cubic kilometer).   

       *(Water production from geothermal based on 7000MW current world installed geothermal energy, and heating sea water from 5degC to 120degC).   

       However this might be a feasible, indeed financially attractive, for regions with high geothermal energy potential, particularly if concurrent electricity generation is possible. Geothermal energy is a vastly under-used resource. Certainly doesn't deserve to be dismissed out of hand.
suctionpad, Mar 25 2004

       as i understood it, water in general (fresh or contaminated) is the problem in central Africa. No water at all means it cannot be purified by [britboys]'s method.
jonthegeologist, Mar 25 2004

       Africa has coastlines too, and it's not the only place short of water. From a geological point of view, is Africa the right sort of place to find geothermal energy resources?
suctionpad, Mar 25 2004

       [suctionpad] the East African rift valley is a (pun intended) geological hot bed. Plenty of opportunity for geothermal energy.
jonthegeologist, Mar 25 2004

       Gee if only BritBoy could come up with some ideas that could be useful closer to home... like say... how about figuring out how to solve this lack of taste problem regarding british food... then there is the dental problem to tackle.

Oh, and how about the innability of the British people to build a functioning, mass-produced car?
hughiebaby, Mar 25 2004

       Or spell?
DrCurry, Mar 25 2004

       Speaking of deposition of salt after distilling seawater by geothermal heat, is that how the great salt beds of the world came into being?
dpsyplc, Mar 25 2004

       Procter & Gamble owns a technology that uses a precipitate to remove contaminents from water. Basically, you mix the powder with water in a pail or tub... and the powder latches on to contaminents inthe water. You let it sit and the powder precipitates to the bottom (solidifies on the bottom). Then you dump the pail of water through a simple coffee filter like fabric and only the clean water goes through.
sirching, Mar 26 2004

       Should work almost as a thermosyphon system, if you use a suitable fluid (silicones?) in a closed circuit deep pipe system with heat exchangers where you can get at them for cleaning at the surface. A rotating drum exchanger with scrapers to remove the salt should be OK. Salt could be recycled into the sea if you are doing this on a coastline, especially if you are not fully evaporating the seawater, so your process out stream is just a bit more concentrated than normal. There are also other minerals that are present in seawater at minor concentrations that could be useful.
unclepete, Mar 26 2004

       hughiebaby why did you just decide to flame me and England? I mean, seriously, you just laid into us for what I can make out as being no reason at all that has anything to do with this post. Seems bizarre.   

       May I suggest you do some yoga or meditate to relax or something?   

       I was going to formulate a clever response to your subtle racism, involving Jaguar (Ford had to buy to move up market), the mini etc.. Then I was gonna move off to slate the USAs single invented foodstock: 'The Bigmac'. But to be honest, I can't be arsed.
britboy, Mar 26 2004

       [hughiebaby] this isn't really the website for personal abuse.....unless it's directed against the French.
suctionpad, Mar 26 2004

       There wouldn't be a real problem cleaning salt out of the water lines since they really don't have to go deep at all. You use a closed loop system to circulate a liquid medium to the depths and then a heat exchanger to heat the water at the surface. What you really don't want to do however is just dump the salt back in the ocean. Can you say "Fish Kill"? How about a trendy new line of gourmet sea salt?
Nitehawk, Mar 26 2004

       If you were to flash distill the salt water then it would gather around the discharge nozzle, and would be easily collected for purposes such as posh table salt, chemical processing etc.
suctionpad, Mar 26 2004

       The fact that the brits have not developed a functioning, mass produced car indicates that they are civil. They have not (yet) utterly subordinated the human being to the automobile. Bravo and three cheers to the supposed "incompetence" of British car designer/manufacturers. The last thing anyone needs is yet another mass produced behemoth guzzling the quasi-petrified rot of dinosaurs and squishing road kill like you and me.
Mungo, Mar 26 2004


back: main index

business  computer  culture  fashion  food  halfbakery  home  other  product  public  science  sport  vehicle