Buoyancy motor with fire

[jimbo]

I was having some breakfast and noticed the pot boiling and thought what if Most buoyancy motors use water and a air pump and deliver like 1/3 extra power or they claim .but here I'm looking at this pot of water and its boiling creating a gradient in the water .why use a motor and pump air when steam bobbles might work .and if you used a very well insolated system you could run it on a candle flame .and be completely in closed .when the water hits boiling point it only needs a very small amount of energy to keep things going .if its well insolated .no big need for hi pressure steam just the desplacement of the water with steam .. And some liquids boil below the human body temp so flame not needed  like ether at around body temp . no electrical needed doable at a camp site scalable ?. Just a thought.

[kajunbee]

https://en.wikipedia.org/wiki/Rankine_cycle

If you understand the physics of the Organic Rankine cycle it may help you reason out how your buoyancy engine might function. Instead of a candle the sun could be your heat source.

[kolbacict]

To get enough work from lifting gas from the bottom, you need to have a sufficient height of the liquid column. A large column of water creates pressure at the bottom, the boiling point will be higher.
It works against us.

[kajunbee]

In closed system although the water column will raise the boiling point the increased gas pressure from refrigerant boiling off will also work against you. You will have to condense that gas cap at a certain rate also.

[jimbo]

Yes a tall column but very well insulated .I saw a buoyancy motor diagram from a couple of researchers and it was a pot or pipe with a shalt in the middle with blades going up it many fan blades they were surrounded with a thin pipe  shield only 50% of the volume was used to go up the other 50% was going down out side of the thin pipe this created a fly wheel effect .they said this design was highly effective .I'd use the flame ...once the boiling starts the flame is all that's needed to continue . as a test unit .I'd use water because its safe .for now .this could be made small for camp fire use .