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Best way to lift a liquid using heat? (SImple pump designs) Answered

I'm overhauling the design of my solar concentrator and now need a good way of lifting a fluid, so as to pour it into a waterwheel and provide rotation.

I have a little solar concentrator and boiler to generate heat or steam. What's the best configuration to give as high a rate of flow as possible? I'm hoping for something in the range of 500 ml per minute, rising about 30 cm.

I've briefly played around with the attached setup, which is a very basic bubble or airlift pump,  The black is my wheel, the blue a reservoir for the fluid (ethanol), the white is the boiler putting out steam (ethanol vapour) and the light blue is a mix of the liquid and bubbles of vapour which rise up the pipe and re-enter the wheel.
It actually works ok, but even optimally only gives a third the rate I'm after.

If necessary I can grab some valves from old bike innertubes, or other basic materials if they'll help.

My previous design was to have the bubbles of steam going directly into the wheel, which was filled with ethanol. This works but requires heating 3 litres of ethanol to just under boiling. Not impossible but a bit of a hassle. I'm hoping lifting a liquid instead will be a bit easier.


You know those cheap coffee-machines, the really cheap filter ones? They have a heater at the bottom which is gravity-fed from a tank, and a non-return valve on the other-end. They spurt hot water under steam-pressure - get one of those.


Sounds appropriate.
I'm having a look around for the design, but would it be possible to jot down a quick sketch of the rough setup?

I'm wanting to keep it home made if possible, there's only so many chucked out coffee machines to salvage.


OK. Your cheap coffee machine has a tank (big blue) which you fill with water. A pipe gravity-feeds down to a tube-heater (electric-heat is red), which also doubles as the hot plate upon which the coffee-jug sits. When the water in the tube boils, it's ejected out the other end, up a vertical riser, then exits onto the coffee in the filter. There's a non-return valve on that side, plastic / silicone rubber tubing that ensures the cold water-feed & steam pressure keep it moving in that way. It's a ball-type thing, very simple & cheap, but it might be what you need.



You'd think the valve would work better on the other side, before the steam phase, to prevent the gas and pressure feeding back.

It's fairly similar to my setup, except I've got the steam fed in rather than generated in the main tube. I haven't got as much heat to play with tho, so don't have their luxury.

I tested it the other day on the stove and it works pretty good. Unfortunately tho either the 0.1% cloruro de benzalconio (benzalkonium chloride?), or the eths fumes themselves (or maybe the spaghetti pescado) poisoned me pretty nastily and I spent the rest of the night throwing up.
A lot.

Not good times. Must be more careful.. (should've taken my fellow squatter's military gasmask when he offered)

It may be on the other side, it's at least 15 years since I took one apart.
You're using ethanol or "meths"?
Meths is poisonous, which is why it's spiked with foul-tasting stuff like denatonium benzoate & pyridine. Pyridine would make you sick (and temporarily sterile) - does the alcohol have a nasty-smell?
Anyway, working in alcohol vapour is hazardous, you should ventilate or avoid letting so much escape - fire / explosionrisk.


It's definitely ethanol. Weird tho, I've worked with it before hot and never had any problems, but by god, this time around... yikes.
I won't go into details, but it was pretty rough.

Yeah so now I'm just waiting for a sunny day to plug the solar boiler into the pump and see what happens. If it works ok, and I'm assuming from experience that it won't, then I'm actually up to the final piecing together stage.
Pretty exiting.

I've added a really simple valve to the end of the fluid outlet; attached.

It's just a rivet, a bit of rubber for a gasket, and a thumb tack. Doesn't seal completely perfectly, but definitely good enough. The flow rate is now about double what it was.