Minto Wheel Idea...

[Oxygon]

I have been thinking on the minto wheel lately and was noticing a few things that may have been responsible for its failure...

So I thought up some things...

The image attached shows a conduit with flexable ends... that always seeks the lowest point... the key here is also that the conduit is never empty...

the conduit is maintained by a ball float valve which either shuts or opens the conduit to flow according to angle...

the reason "I think" the conduit should be maintained is that it takes considerable pressure to force the boiling liquid up the conduit and this wastes the energy and creates a positive pressure in the opposing reservoir which makes it even harder to transfer fluid...

just my 2 cents...

[ken_behrendt]

Oxy...

I'm not too sure how this is supposed to work. Is the "conduit" the compartment containing the water or is it the flexible hose that flops around in the compartment? Is this supposed to work by some sort of siphoning aciton? You mention "boiling water", but it is unclear how the water in the chambers is heated.


ken

[jim_mich]

The failure of the Minto Wheel was directly caused by a lack of proper engineering. The MEN (Mother Earth News) built a half-assed poorly designed wheel. When it failed to work like Wally Minto's smaller wheels they gave it a thumb's down. Everyone that has tried to build it since have followed in the MEN footsteps and made the same design mistakes. Stop and think! Every rotation the fluid must move though the pipes twice. Try filling a barrel with a garden hose. It takes a long long time. The pipe must be big enough so that it does not restrict the fluid flow. The MEN used pipes that were WAY TOO SMALL. Every rotation each tamk must heat up and cool down along with the fluid. The MEN used tanks that were TOO THICK AND HEAVY. The tanks must first heat up before the fluid can heat up. Heavy walled tanks slowed down the heat transfer speed, which slowed the wheel.

A gasoline engine runs on a temperture difference of about 800 degrees. A Minto wheel can run on a temperature difference as low as 12 degrees. That was it's strong point. But you can't just slap together any old tanks and pipes and expect the thing to work like a charm. The MEN people were not engineers. They were just backyard handymen.

[Oxygon]

I fully agree with your statement "jim_mich"...

I would like to add a response to "ken_behrendt"...

the picture I added is simple, The conduit I talk of is the pipe you see as a black line running from each liquid reservoir. the conduit is a sloid structure of pipe until it reaches the resiviour itself... once inside it becomes slack and fall to the lowest point with the aid of a weighted ball at its end. I believe that keeping the conduit emerged in the boiling liquid will reduce the pressures needed to overcome flow resistance.

I have been researching this design recently and have become familiar with getting liquid to flow up and out a pipe. If the pipe already has liquid in it... its easy, but getting it to flow up and out very difficult. SO if you can keep the conduit full it reduces the energy needed to exchange the liquid.

pls also the exchange of liquid from bottom to top can occur longer because the "flex-conduit end" remains at the lowest point.

just my 2cents on an old idea...

"jim_mich" if I had the money/skill I build it!

If I ever do I will...

[ken_behrendt]

Jim...

Thanks for your excellent explanation of the "Minto Wheel". For some odd reason, I thought that it might be a mispelling of Minato Wheel and was wondering where the magnets were!

Obviously, this is not perpetual motion but just a kind of heat/gravity engine. It reminds be a bit of that "drinking bird" novelty that one sees in novelty shops and flea markets. In that device, the cooling due to evaporation of the water on the bird's absorbant beak material results in a pressure drop in the bird's head that draws up a low boiling point liquid into the head from the belly to unbalance the bird and make him take another drink. After he bends (falls) over to again wet his beak, the liquid in his head can run back into his belly and the imbalance again erects him so that the cycle can be repeated.

In the Minto Wheel, the drinking bird is replaced by multiple opposed chambers with the low boiling point liquid in them. Now, however, the liquid is forced into the upper chamber by a pressure build up in the opposed lower chamber due to it being warmer than the upper chamber.

Yes, I believe that this device is workable, but can only produce energy as long as a temperature difference is maintained between the top and bottom of the wheel. I suspect that in actual operation, maintaining that temperature difference might be more difficult than anticipated.



Oxy...

If you ever do attempt building such a device, then I recommend that you do it outdoors where there is plenty of ventilation. I almost bought one of those drinking birds once and noticed a warning on the box it came in. That low boiling point liquid that is used is toxic and it recommended that, in the event that the bird's glass body shattered, one open one's windows until the vapors were completely dissipated. It's too bad that some way can not be found to make this thing work with water.



ken

[jim_mich]

Ken, it will work with water! The trick is to compleatly fill the tanks and pipes with water so no air exists inside, then remove about half of the water. The removal can be accomplished by vacuum pump or by boiling the water. I once filled a Mason canning jar with water and screwed on the canning lid, then boiled the jar inside a covered canning kettle for an extended time. When the jar cooled the lid sealed and contained about 2/3 water and 1/3 water vapor. When I place an ice cube on top of the metal lid the water boils. When I hold a lighted match under the jar it immeadiately boils even though the jar is still cold.

Different liquids require different amounts of heat to boil. I think water requires more compared to other liquids making it a poor choice. Once again engineering (choosing the right materials, dimensions etc.) is important.

[ken_behrendt]

Jim...

I do remember seeing a demonstration in my high school chemistry class in which water was placed into a glass flask and then the air above it was sucked out with a powerful vacuum pump. When the manometer pressure in the vacuum line reached about 76 mm of Hg or thereabouts, the water started boiling vigorously even though the water was only at room temperature!

Well, if that is the case, the it should not be too difficult to build a heat / gravity engine using this principle. One could have large wheel with spherical tanks arranged along its rim. Diametrically opposed tanks would be connected by piping. The axle facing surfaces of the tanks would be painted flat black and the outward facing surfaces painted with shiny aluminum paint.

Then, on a sunny day, the tanks at the bottom of the wheel would absorb sunlight and heat up while the tanks on the top of the wheel would reflect sunlight and stay cooler. Result...water at ambient temperature in the bottom tanks would "boil" and the pressure would pump the water from the lower tanks to the top tanks.

Hey, wait a minute! The pressure created in the lower tanks might not be enough to pump the water from them to the top tanks! Hmmm...I didn't figure on that possibility.

I think making one of these work might be a bit more complicated than we imagine...


ken

[Jon J Hutton]

I realize this might be basic for some on the drinking bird idea but its worth the review.

Technically, the Drinking Bird is a type of "Heat Engine". But thankfully you won't need a degree in physics or thermodynamics to understand the basics of how it works!
The body of the bird comprises 2 glass "bulbs", one for the head and one for the lower body.
The glass tube which interconnects the two bulbs dips deep into a special liquid (usually coloured methylene chloride) in the body.
An important fact is that the bird will "drink" providing the head bulb is slightly cooler than the body bulb (i.e. there is a "temperature differential").
The head is usually coated in a red felt-like material which absorbs water when the bird "drinks". Evaporation of water from the head causes the head to become cooler than the body. By lucky coincidence, the swaying motion of the bird assists the evaporation.
Although the head and upper part of the glass tube appear to be "empty", they are actually full of invisible vapour from the methylene chloride. Methylene chloride is good for this because it doesn't take much heat energy to turn it into a vapour (It has a "low latent heat of evaporation").
Because the head is cooler than the body, some of this vapour condenses inside the head, like steam when it touches a cold window.
As this vapour "shrinks" into minute droplets of fluid, it takes up a lot less space. This makes the pressure inside the head slightly lower than the body, causing the liquid to be sucked up the tube. You could also think of it as the "hot" fluid in the body making "steam" above itself, which blows the liquid up the tube (vapour pressure); it's all relative. The main thing is, the body is always warmer than the head. It's not the same a thermometer, though, because it does not rely on expansion of the liquid itself, which is insignificant. It's the pressure of the vapour that does the work.
As the liquid rises up the tube, it gradually changes the centre of gravity of the bird. This makes it tip over more and more until eventually it tilts into the water. If everything is adjusted just right, then as it tilts over, the end of the tube inside the body comes out of contact with the liquid. Instead of pushing the liquid up the tube, the vapour above the liquid in the body can now quickly rush up the tube, equalising the pressures in head and body. As this happens, the liquid which has moved up towards the head now gurgles back down into the body. This rapidly moves the centre of gravity back to the lower body, and the bird swings back away from the glass.

When you understand how the bird works, you will see how you can even "trick" it to "dip" with no water at all:
If you shine a lamp towards only the bottom part of the bird, this slightly warms it (compared to the head), so there is the necessary "temperature differential" and it should "dip".
If you have just shown your friends how the bird works (with water), then you may perhaps puzzle them again by removing the glass, and watching it continue to drink long even though the head has become dry, secretly using the warmth from a lamp nearby (which may have been on before). Take care, though, because excessive heat will burst the glass and make a terrible mess! (Thanks to Jan at "Arabesk" for this interesting trick)

[ovyyus]

Good explanation of how the drinking bird works Jon. I used to make and sell these - they are great fun.

As you say, a drinking bird type system is capable of harnessing hot bottom/cold top thermal gradients. But naturally occurring (free) thermal gradients are always hot top/cold bottom - such as the normal thermal stratification that exists in a closed room containing a heat source. A heat pump utilising modified drinking bird physics, that is able to harness natural hot top/cold bottom thermal gradients, can result in a system that appears like PM - but only while a floor/ceiling temperature difference exists in the room in which it operates.

[Fletcher]

Bill .. as an interested follower of your thermal gradient principle, I like it for a number of reasons, so it must be considered a possibility in my books. It has simplicity (like the Sterling engine or the Minto wheel) & the principle can be found in nature in abundance. I just don't know how to effectively apply it to duplicate Bessler's feats :(

..My question is (to your knowledge) did Bessler ever give a public test or display of his wheels out doors in the open air, or perhaps in a very large room or auditorium with relatively few people in it, where it would be difficult to develop a meaningful thermal gradient he could use ?..

I realize the long duration test was conducted in a locked room scenario, without observers to provide body heat etc, so this also may be problematic in explaining the use of a thermal gradient. I guess we can never know whether the room for the test was vented &/or ducted to provide or take away heat or whether it was a completely locked door/closed room scenario.

If Bessler did conduct _any_outside tests then this increases the intrigue further. If they were _only_ conducted indoors or say in large rooms with a fair sized audience, then this could support your theory & certainly wouldn't discount it.

..I'm guessing that they were all indoor public displays or tests & this maybe is why you display a strong preference for the inclusion of an environmental factor to compliment gravity, which then allows a surplus energy equation ?..

[ovyyus]

Hi Fletcher, I don't think Bessler ever displayed a working wheel outdoors, or in a room that was considerably larger than his wheel diameter.

An inactive person outputs over 100 Watts of heat to his environment. Calculations put Bessler's largest wheel output at only about 1/4 of this. Therefore, it might not be such a stretch of the imagination to consider that a group of active people buzzing around in a room might represent an unexpectedly high source of free heat.

In a closed and unoccupied room, such as was the case with the long duration test, other considerations for a potential heat source are required. These might include solar input through windows and/or thermal transfer through walls and doors from adjoining heat sources (fireplaces, etc).

A mechanism designed to harness free thermal gradients in order to lift weights and create a constant wheel overbalance is a possibility that shouldn't be discounted. Given the physics and history of the various approaches adopted by those searching for Bessler's secret, I'm always tempted to conclude that a thermal solution represents the best chance of success. But of course, just like everyone else here, creating a pet theory and applying it to a real world solution are two different problems ;)

Here's an interesting experiment: take two thin metal disks, say about the size of dinner plates, and join them flat face to face, soldered and sealed around their rims only. Because the disks are slightly flexible, pulling each away from the other will result in a central cavity. Fill the cavity completely with a volatile liquid such as alcohol (Methylene Chloride would be better) making sure there is no trapped air. Now, pulling the disks apart will create a vapour bubble - release them and the vapour bubble will instantly collapse. Tension the disks with an appropriate spring force so that a vapour bubble is maintained. Any change in the temperature of this system will now result in variation of the fixed tensioning force as the bubble vapour pressure alters with temperature. The result is that thermal variation is transformed into mechanical movement. The large surface area to volume of the disks makes the system quite responsive, particularly when copper disks are used. I'm not saying Bessler used a system such as this, or that it could be made to work within the historical restrictions, but it is within his ability and it is fundamentally simple. On the run here, hope this makes sense.

[jim_mich]

As Bessler's wheel was turning then the inside air would be mixing. There would be no thermal gradient inside the wheel. There would be no way to harness thermal gradients in a room.

It would be near impossible for any thermal system within the wheel to function at the speed that the wheels turned without either a sudden source of heat (such as an internal compustion engine) or a large source of heat (such as a steam boiler).

Bessler said something about his wheels being unaffected by freezing cold.

Just my opinions.

[ovyyus]

Jim, a turning hollow disk can indeed have an internal thermal gradient - CF will cause warmer air to 'gravitate' towards the centre of rotation. Feeding cool and/or warm air in/out at the rim (Wolff described peering through a slit at the rim) might possibly maintain a considerable internal gradient - which could even increase with speed.

It may well be 'near impossible' to create a thermal solution. But then again, it also seems near impossible to create a 'true PM' solution.

Thermal gradients occur in all temperatures, therefore Bessler's comment about operation in freezing cold can't be used to support the cased one way or another.

[Fletcher]

Add to that that barometric clocks that didn't need winding had been invented, circa Bessler's time, & the precedent for inventiveness, not always based on necessity, is established.

[ovyyus]

Yes Fletcher, James Cox comes to mind. Cox considered his barometric pressure clock-winding mechanism to actually be PM - and that was well after Bessler, in the 1760's. The physics of heat and pressure were obviously still very much a mystery back then.