# perpetual motion free energy by siphoning

Discussion in 'General Science & Technology' started by tablariddim, Oct 23, 2004.

Not open for further replies.
1. ### phlogisticianBannedBanned

Messages:
10,342
Wrong kid. The moon is losing gravitational energy as it perturbs the earth's crust and makes tides. This loss of energy causes the moon-earth relationship to lose energy.

from;

G=m1.m2/r^2

you see that this implies that 'r' increases, and this has been verified experimentally.

So perhaps you should read more, and 'think' or assume less?

3. ### RawThinkTankBannedBanned

Messages:
429
So U mean to say to take moon out of earth orbit or in upper orbit , U actually extract energy in pushing it up ???

So why build dams ? Just throw water up.

5. ### phlogisticianBannedBanned

Messages:
10,342
No, that's not what I'm saying. The Moon isn't being 'pushed' up. The Moon and Earth are a gravitational system, and that system has gravitational potential energy. This energy is tapped off slowly and we see this expressed as tidal disruption on earth.

Look at the the equation? How can you make G smaller? For two fixed masses? It's obvious!

Throwing water up is a different case isn't it?

7. ### eburacum45Valued Senior Member

Messages:
1,297
Geosynchronous orbit.

That is the key; the Moon is further away from the Earth than geosynch, so extracting energy by tidal friction makes it recede.

If you had a large satellite in an orbit closer than geosynch tidal friction would drag it down.

8. ### MacMRegistered Senior Member

Messages:
10,104
Years ago I actually did a study on doing just that. Running large lines from LA,Calf over the Mtns and into death valley. The idea was to create a large body of water in the desert area to change the cimite. i.e. - Irrigate the desert.

It turns out that there is a problem with that. You can only suck up to atmospheric pressure. Siphons create a suction by the gravity on the low side being greater than the gravity pull on the higher side.

However, typically water contains disolved gases to the tune of about 5% by volume and when you subject water to a vacuum it degases (the gases seperate from the water). In the case of the pipes going over the mtn you form a large gas bubble at the apex of the siphon.

Also believe it or not water will boil at 32.114 F and 0.0226 Psia. I've done it. You will have steam bubbles rising slowly through a slushy ice. It is called Three Phase Equilibrium or "Triple Point".

At a sea temperature of 60 F the sea water would start to boil with an elevation pressure (suction) differential after 33.365 feet of elevation head siphon suction.

Your water will start to flash to steam at the apex of the siphon.

http://www.sciforums.com/attachment.php?attachmentid=3556&stc=1

9. ### catoless hate, more scienceRegistered Senior Member

Messages:
2,959
Yeah, I learned that stuff in chem class; I don't know why I didn’t think of it. If changing the climate was your objective, and not getting energy, you could expend a lot of energy/manpower and tunnel under/through the mountains and just run it like a canal instead of a siphon.

10. ### MacMRegistered Senior Member

Messages:
10,104
Well trace out a contour map and you will see a huge lake hundreds of square miles. It would indeed change the weather patterns.

But that step is not known as to it's ultimate consequences and I decided all those people probably wouldn't want to move anyhow.

11. ### Billy TUse Sugar Cane Alcohol car FuelValued Senior Member

Messages:
23,198
Sorry about taking so long to respond and of course I agree that we can not defeat the law of conservation of energy. The energy this impratical system iscontinuously produced by solar energy, which is continuously supplied by the sun.

I won't go into details about why your "bouyancy" objection is wrong as one-time start-up effects are irrelevant to any system continuously producing energy.

Few people realize how much solar energy is "stored" in salt. More geological dome structures are filled with salt than with oil, but there is more solar energy stored in salt than in the same volume of oil! Obviously it is not releasible by burning salt, but the osmotic pressure of a saturatred salt solution (room temperature) against pure water will lift the salt water to enormous heights (I forget the exact number but it is around 500 feet.) Eventually the pressure difference produced by the difference in water column heights will stop the flow of fresh water into the saturated solution, via reverse osmosis.

Think what energy you would get from a dam 400 feet high with salt water spilling over the top. Then you will understand that a huge amount of solar energy (that reversibly evaporated the water to make the salt) is in fact stored in salt.

Unfortunately no one has ever figured out how to get it back economically athough some very low power, very expensive systems, like the "fresh water fountain" floating in the sea have been suggested. (Not my idea, but a very clever one. Tube length must be many times the osmotic limit so the pressure difference between sea water outside and less dense freshwater inside is more than enought to drive reverse osmosis - i.e pure water continuously enters the fresh water column inside the tube via the osmotic membrain sealing the bottom of the tube. An equal volume of fresh water flows out of the tube top and falls back into the sea, if not harnesed to turn a turbine. You could get both energy and fresh water from the sea with no pumps etc.!)

12. ### neil coxRegistered Senior Member

Messages:
65
Hi BillyT: I'm intreged by your fresh water fountain. Why many times? If 500 feet is the limit of osmotic pressure, why wouldn't 5000 feet be sufficient to produce a low flow rate a few inches above the surface of the ocean? Ocean water has a density of 1.1~~ 10% more than fresh water? Ships could refill their fresh water tanks by pumping the fresh water out of the top of the tube. It would not be zero energy except for small ships which could syphon the water to a tank below the water line. The 5000 foot tube would be moderately costly and the osmotic membrain would fail perhaps once per year after supplying millions of gallons of fresh water. Would the water quality be excellent or not so good? Neil

Last edited: Jun 8, 2005
13. ### Billy TUse Sugar Cane Alcohol car FuelValued Senior Member

Messages:
23,198
Niel - I don’ think the fresh water fountain is economically attractive, and possibly not feasible when storm are considered. It is IMHO just an interesting concept that helps one understand (if they try) some physics related to osmosis.

I don’t know exactly what “many times” was refering to - have not read my original post. To use your number of sea water being 10% denser than fresh water there would be no osmotic pressure difference across the membrane at the bottom of a tube if 10% of it were sticking out of the ocean and the inter was full of fresh water. What would happen if this were the “initial condition” is the level of the fresh water would fall down towards sea level (and even below it, unless the tube is very long) that is to prvent the fresh water from passing thru the membrane by osmosis in an effort to dilute the ocean, the fresh water column height must be about 500 feet less that the salt water depth to bottom of the rube. This 500 feet less of less dense fresh water will make a presure difference across the membrane large enough to drive “reverse osmosis” flow. That is some H2O from the sea will be flowing into the fresh water column.

Note that the length of the tube (How far the lower end of the tube is below sea level to be more exact) will determine whether or not the top of the fresh water column is above or below the sea level.

For example, if the bottom of the tube were 10,000 feet below sea level and the vertical tube were 11,000 feet long, then with the top of the fresh water column could be 100 feet above sea level and yet the fresh water pressure on the bottom membrane would be 1x 10,100 feet of pressure and the sea water pressure on the other side of the membrane would be equal to 1.1x10,000 feet of fresh water, or 11,000 feet of fresh water’s pressure. That is the net pressure across the membrane would be 900 feet of fresh water column higher on the sea water side. As this is more that the approximately 500 feet required to drive reverse osmosis, H2O would be flowing in to the fresh water column and the water level would be come more than 100 feet above sea level. When it is 200 feet above sea level, there is only 800 feet of freshwater pressure to dive reverse osmosis and the rate of flow of H2O form the sea into the fresh water column would be at a lower rate. When the top of the fresh water is 500 feet above the sea level, there is only 500 feet to drive reverse osmosis, and with approximately this pressure higher on the sea side of the membrane, the reverse and normal osmotic flows are equal. Consequently the top 500 feet of the 11,000 foot long tube is useless and can be cut off, and the “float collar” around the tube which keeps it from sinking to bottom of the ocean can have a little less displacment.

Even when your drain off fresh water at the flow rate it is entering when the fresh water is only 100 feet above sea level, don’t expect many gallons. Per minute flow unless you have spent a lot of money to have a large membrane surface. In practice your membrane is both large surface and strong enough to resist the pressure difference across it only if it millions of fine U shaped “straws” all the ends of these straws pass thru and seal with small holes in the bottom plate that closes the end of the tube. The outer surface of each U shaped tube is in contact with the sea water. That is each “straw” has significant surface exposed to sea water and yet because the excess sea water is trying to collapse a very fine “straw” the straw is not collapsed. This is the design used on submarines to get fresh water from the sea via :reverse osmosis and these assembles of millions of U straws with ends sealed in a plate is commercially available now.

If you want to start up an energy and fresh water “free” from the ocean company, don’t count on me as an investor. I don’t think there is anything wrong with the physics (I am sure there is not, but may have a few values wrong in my illustration) What scares me is the cost of the tube, the membrane etc. compared to the value fresh water and a little “free” energy in the middle of the ocean, especially if the site is ever subject to strong waves.

PS the quality of the fresh water is excellent - like distilled water.

Last edited by a moderator: Jun 8, 2005
14. ### ObewanRegistered Member

Messages:
1
Wow,
Sounds like alot of it can't be done and there is no way a perpetual motion machine can be made. I happened to be researching syphon for a little project I am thinking of doing and yes I want my water to go up hill, about nine feet and then back down again etc. I guess what peaked my interest was the perpetual motion concept. This is definitely a possiblity and when I envision the use of the earths known fields. I look at not the fact the machine will not run 100% of the time but that it will work when it is suppose to and with no energy from man inserted in the equation. Will what ever is built "create energy" as a by-product of the design that is constructed. I think we all know that this can be done and I think we all should look hard at all the possiblities. Hybrids....we all new this type technology and battery generation existed years ago....it just took money. If you have money I will build the machine for you....its really that simple. Of course if everyone with the desire got together and bounced ideas off each other...probably several hundred prototypes of concept machines could be designed and built all over the world. Which one of you guys is loaded enough to commit to a group research project to change the world........ that is the real question.
Obewan

15. ### kevinalmRegistered Senior Member

Messages:
993
No. Pretty sure the energy source is the Earth's rotational kinetic energy. The moon's tidal effect on the Earth slows rotation down and the Earth's tidal effect on the moon boosts the moon into a higher orbit.

Messages:
33,264
17. ### Billy TUse Sugar Cane Alcohol car FuelValued Senior Member

Messages:
23,198
Hard to tell what "machine" you are tlking about, but if you are thinking that the fountain of fresh water in the deep ocean is a source of energy from geravity, you are wrong. Perpetual motion machines are not possible. The fresh water fountain falling back to the surface of the ocean could turn a turbine, but it is driven by the difference in salt concentrtions. This difference is due to solar evaporation of the sea concentrating the salt. Thus the fresh water spouting out of the sea will stop eventually if the sun did not shine. I.e. it is a solar energy system.

18. ### geistkieselValued Senior Member

Messages:
2,471
Tablariddim, A clever concept.
I drew a simple picture that required the siphoning tube to be below th surface of the ocean which would require a huge basin to accumulate water. However the reverse process of pumping the water back into the ocean may pose a problem as the water would need to be elevated at least slightly higher than the surface of the ocean. If this problem can be overcome it would thereby limit the need for the size of the collector basin. Using the momentum of the water after spinning the generators, the water could be given a head start in returning it to the ocean.
As in the pressure in the water faucet the head as it is called is the difference in the height of the water source the ocean and the depth of the basin which is the biggest technological problem that I see. The bigger the radius of the pipes the less head needed as spin velocity of the generators can always be adjusted with gearing systems. There is a "best arrangement" some where here.

Geistkiesel

19. ### geistkieselValued Senior Member

Messages:
2,471
Don't give up yet. The destination need be in some place like Death Valley, but no water need be dumped there. I like the idea of buckets in the ocean that is lower yet than Death Valley that when "full" could just be emptied where they stood and then pulled down to receive more water.The filling biuckets could be geared by cable to an adjacent bucket pulled down by the filling bucket.

Geistkiesel

20. ### geistkieselValued Senior Member

Messages:
2,471
But once lowered wouldn't the device work perpetually?

Geistkiesel

21. ### Billy TUse Sugar Cane Alcohol car FuelValued Senior Member

Messages:
23,198
It will work (a fountain of fresh water over flowing a pipe sticking out of the ocean) as long as the sun evaporates the fresh water of rivers flowing back into the ocean (I.e. as long as rain falls on the Earth.) It is a not a magic source of energy, but a solar energy sysetm.

22. ### AnomalousBannedBanned

Messages:
1,710
High tides?

Create a canal near equator on large islands with no hills or mountains in way. The canals height should be up to the level of max hightide (all the way) and with depth up to the lowest tide sea level.

At high tide sea water will start rushing in the canal and being too long the water will travel all the way towards the other end of the island. Use this sea water flow to create large amounts of electricity. ie. wider the cannal the greatr will be power.

23. ### FlunchRegistered Senior Member

Messages:
67
There are tidal generating plants running in Canada, France and Russia. I suspect many more will be built in the next few decades. The available energy is proportional to the head generated (height differential between the tides). Places with large tidal swings and natural channels/inlets are good candidates.