rjbutwell Posted April 27, 2016 Share Posted April 27, 2016 Long, Long ago, I brought my idea for reversing entropy to my college thermodynamics professor. He couldn't figure out why I was wrong but kind of politely ushered me out of his office after an hour. Well, over three decades later, I want to cross this off my list. Would a physicist kindly review my thoughts and tell me why I'm wrong? I would greatly appreciate it and thank you in advance. The link is - Link removed Sincerely, Rob J Butwell 1 Link to comment Share on other sites More sharing options...
J.C.MacSwell Posted April 27, 2016 Share Posted April 27, 2016 (edited) Long, Long ago, I brought my idea for reversing entropy to my college thermodynamics professor. He couldn't figure out why I was wrong but kind of politely ushered me out of his office after an hour. Well, over three decades later, I want to cross this off my list. Would a physicist kindly review my thoughts and tell me why I'm wrong? I would greatly appreciate it and thank you in advance. The link is - www,rjbutwell.com Sincerely, Rob J Butwell How is this different in principle from how hydroelectricity is commonly generated? In principle it could work (without breaking any thermodynamic laws) . Can you make it efficient enough to be useful? Note that the energy is provided by the atmosphere (Sun) in both cases, to provide water at a higher elevation...gravitational potential energy. Edited April 27, 2016 by J.C.MacSwell Link to comment Share on other sites More sharing options...
rjbutwell Posted April 27, 2016 Author Share Posted April 27, 2016 Thank you so much for your reply. It is different because we are in a closed system, no outside energy enters or leaves our box. So no solar energy is allowed. Our only source of energy is any potential energy in the system and heat energy. The temperature in the closed system starts at 70 F but will decrease as we harvest the heat energy. Rob Link to comment Share on other sites More sharing options...
J.C.MacSwell Posted April 27, 2016 Share Posted April 27, 2016 Thank you so much for your reply. It is different because we are in a closed system, no outside energy enters or leaves our box. So no solar energy is allowed. Our only source of energy is any potential energy in the system and heat energy. The temperature in the closed system starts at 70 F but will decrease as we harvest the heat energy. Rob You could put the same constraints on the turbine. In time either system, if isolated, would come to a stop. They both need a source of energy to keep going. You seem to recognize that, so what is it that you believe is unique in your system with regard to entropy? Link to comment Share on other sites More sharing options...
rjbutwell Posted April 27, 2016 Author Share Posted April 27, 2016 Good question. The turbine requires a force on it's blades, which comes from the force of gravity on the water. So, we are changing the water's gravitational potential energy into electrical potential. With the our heat machine, we are just harvesting heat energy. According to the Kelvin-Planck 2nd Law corollary, that is impossible. So, it comes down to, can we harvest heat energy in a single temperature environment? If we can, we ahave a perpetual motion machine of the 2nd kind. This is a closed system, no light, no sun, nothing comes in except the force of gravity. I really appreciate you helping me, Rob Link to comment Share on other sites More sharing options...
pzkpfw Posted April 27, 2016 Share Posted April 27, 2016 If it's a closed system, where is the atmospheric water coming from? Link to comment Share on other sites More sharing options...
rjbutwell Posted April 27, 2016 Author Share Posted April 27, 2016 We are in a closed system. there is a pool of water at the bottom., by design. , Rob Link to comment Share on other sites More sharing options...
J.C.MacSwell Posted April 27, 2016 Share Posted April 27, 2016 Good question. The turbine requires a force on it's blades, which comes from the force of gravity on the water. So, we are changing the water's gravitational potential energy into electrical potential. With the our heat machine, we are just harvesting heat energy. According to the Kelvin-Planck 2nd Law corollary, that is impossible. So, it comes down to, can we harvest heat energy in a single temperature environment? If we can, we ahave a perpetual motion machine of the 2nd kind. This is a closed system, no light, no sun, nothing comes in except the force of gravity. I really appreciate you helping me, Rob The bold is true of your system also. So why can I not claim my turbine system is a heat engine as well, with my pool of water evaporating at the bottom and condensing in my "Macswell's Condenser" (complete with a team of Macswell's demons to work it) at the top? Why will this not work? It is a similar uphill battle in each case. I can't design the condenser I require, and you will not find a hygroscopic substance and box opening/closing system that will do what you require. Admittedly part of a circular argument, but the reason we know that is because of the 2nd law of thermodynamics. Link to comment Share on other sites More sharing options...
pzkpfw Posted April 27, 2016 Share Posted April 27, 2016 We are in a closed system. there is a pool of water at the bottom., by design. , Rob Sure, but what makes that water "atmospheric"? Link to comment Share on other sites More sharing options...
Eise Posted April 27, 2016 Share Posted April 27, 2016 How much energy is needed to remove the water from the hygroscopic substance? Link to comment Share on other sites More sharing options...
Strange Posted April 27, 2016 Share Posted April 27, 2016 Well, over three decades later, I want to cross this off my list. Would a physicist kindly review my thoughts and tell me why I'm wrong? I assume you don't understand how hygroscopic materials work. What were you planning to use? Hygroscopic materials will either bind water to the surface (adsorbtion) or dissolve in the water they attract (deliquescence). It sounds like you are thinking of the latter. In both cases, there is a limit to how much water will be absorbed. It will require energy to recover the hygroscopic material (either driving the water away from the material or recovering the salt from solution). That is the energy that turns the wheel. If hygroscopic materials worked as you suggest, then an even simpler method would to simply have a large funnel containing the hygroscopic material. It would attract water which would run straight out of the bottom of the funnel. This could then be used to turn a water wheel. (I hope that shows why the idea can't work.) Link to comment Share on other sites More sharing options...
swansont Posted April 27, 2016 Share Posted April 27, 2016 Eise's question needs to be answered. "The water is removed from the hygroscopic substance" is masking a lot of the issues here. Link to comment Share on other sites More sharing options...
rjbutwell Posted April 27, 2016 Author Share Posted April 27, 2016 I really appreciate the feedback. J.C. - no water would condense on your turbine because we are in an isothermic environment, everything is at 70F. PZK - Water naturally mixes with air. There is a limit depending on the air temp. In a closed system, humidity will be at 100% regardless of Temp. Eise- Im not a chemist but there are so many different water attracting substances. It depends on which one you are using. I calculated the energy to remove water from one substance by reverse osmosis and it was doable. It is an easy calculation. Just water weighs 18g per mole, 3785grams/gallon, 210moles per gallon, 1 gallon weighs 8.3 lbs, 1 footpound =1.36 Joules. So, if we had a hygroscopic substance that absorbed twice it's weight in water and we started with 100lbs of the substance, it would absorb 200lbs of water. If we had it at 1000ft, we would get 100,1000 foot pounds of energy or 136,000 joules. That would be 1000 watts for over 2 mins. At 10,000 ft, we would have a hair dryer running for 20 mins. We need a chemist to find the right hygroscopic substance for us. Do you know one. He would probably have an immediate answer. Common knowledge for a chemist. Strange- Interesting idea, but the hygroscopic substance binds with water and would run at all. Your right about picking the best hygroscopic substance that we have to remove the water from. We have a lot of play on the energy available, just by raising the dry substance before it soaks up the air mositure. Swan - I think your right, we want a hygroscopic substance that absorbs lots of water but is lightly bound to it. So we have the surplus energy(from harvesting the positional or gravitational potential energy), after removing the water. Link to comment Share on other sites More sharing options...
Enthalpy Posted April 27, 2016 Share Posted April 27, 2016 Like the other answers, I have nothing against producing work with that wheel. It just needs some means to remove the humidity from the hygroscopic substance when at the bottom of the path. This removal takes some form of energy, for instance heat, in which case the operation would be an engine. Link to comment Share on other sites More sharing options...
rjbutwell Posted April 27, 2016 Author Share Posted April 27, 2016 Thank You very much for taking the time to look at my post. Did you go to the website? There is much more there. Link removed It explains the hygroscopic method very well, plus there are a few other methods to accomplish this task. Thanks Rob Butwell Link to comment Share on other sites More sharing options...
Strange Posted April 27, 2016 Share Posted April 27, 2016 He couldn't figure out why I was wrong but kind of politely ushered me out of his office after an hour. I'm sure he could see exactly what was wrong. But was unable to get you to accept it. Link to comment Share on other sites More sharing options...
rjbutwell Posted April 27, 2016 Author Share Posted April 27, 2016 Nope, he said, "I can't see where you are wrong, make this your senior project." Did you check the website? I don't think you have seen all of the material. Link removed Thanks very much for your help, Rob Link to comment Share on other sites More sharing options...
Phi for All Posted April 27, 2016 Share Posted April 27, 2016 Did you check the website? I don't think you have seen all of the material. ! Moderator Note Perhaps you could copy over the relevant points? We're not here to advertise for your site, and it's against our rules to promote it. Link to comment Share on other sites More sharing options...
Klaynos Posted April 27, 2016 Share Posted April 27, 2016 ! Moderator Note I've removed the links. Link to comment Share on other sites More sharing options...
Strange Posted April 27, 2016 Share Posted April 27, 2016 It explains the hygroscopic method very well, plus there are a few other methods to accomplish this task. OK. So let's see the detailed analysis of energy in and energy out (with references to the sources of any data used). Link to comment Share on other sites More sharing options...
rjbutwell Posted April 27, 2016 Author Share Posted April 27, 2016 I wasn't advertising anything, the webpage about 10 pages and was solely about this problem and had no other material on it at all. And there were no advertisements at all. I wasn't selling anything. I wish the moderator had at least looked at the page, oh well. But the moderator removed the links. Well, if I'm right you'll hear about it in the news . Thanks to those who gave the problem a go. Sincerely, Rob -1 Link to comment Share on other sites More sharing options...
Phi for All Posted April 27, 2016 Share Posted April 27, 2016 I wish the moderator had at least looked at the page, oh well. ! Moderator Note I'm not paid to look at the page, I'm paid to enforce the rules. Oh, and I'm not paid. Did you miss the part where I invited you to post the relevant parts of your idea from your site into the thread? So people know what parts you claim they didn't read? If you refuse to do that, then it does seem like you were at least driving traffic to your site. Just sayin'. Your call. Support your ideas with the material available to you, answer some of the questions others have posed. Scientific discussion dies without these. Please Report this note if you have a problem with it, instead of responding to it in thread. Link to comment Share on other sites More sharing options...
studiot Posted April 27, 2016 Share Posted April 27, 2016 (edited) It is not up to us to thermodynamically analyse this mechanism for you, it is up to you. So Strange's request for a First Law is valid. I would add the question what about the energy to open and close the box lids, Where does that come from? Are we are ignoring friction for this thought experiment? Note that mechanical device that does work lifting a weight without friction involves zero entropy change. Anything open to the atmosphere cannot be a closed system. So let us have a proper thermodynamic analysis to discuss. Edited April 27, 2016 by studiot Link to comment Share on other sites More sharing options...
pzkpfw Posted April 27, 2016 Share Posted April 27, 2016 (edited) ... PZK - Water naturally mixes with air. There is a limit depending on the air temp. In a closed system, humidity will be at 100% regardless of Temp. ... First, I don't believe humidity will be 100% at any temperature. Can you provide backup for that claim? Secondly, if you're relying on water naturally evaporating into the air from the pool at the bottom, and simply opening the containers when they're at the top; how do you remove water from the containers when they're at the bottom? i.e. why doesn't water in the air simply re-enter? ... So, if we had a hygroscopic substance that absorbed twice it's weight in water and we started with 100lbs of the substance, it would absorb 200lbs of water. If we had it at 1000ft, we would get 100,1000 foot pounds of energy or 136,000 joules. That would be 1000 watts for over 2 mins. At 10,000 ft, we would have a hair dryer running for 20 mins. ... How does this take into account the speed at which your substance absorbs water? i.e. when you open the containers, do the substances instantly absorb their full amount of water? Edited April 27, 2016 by pzkpfw Link to comment Share on other sites More sharing options...
J.C.MacSwell Posted April 28, 2016 Share Posted April 28, 2016 (edited) I really appreciate the feedback. J.C. - no water would condense on your turbine because we are in an isothermic environment, everything is at 70F. That's where the Demons come in...you can't beat the second Law without them. I could of course use your hygroscopic system at the top, continuously removing water from the air and dispensing it into the reservoir...more Demons Edited April 28, 2016 by J.C.MacSwell Link to comment Share on other sites More sharing options...
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