Compressed air powered water pressure

[berkeman]

A ram pump is not a viable solution here. It uses a lot of low head water to pump a little (maybe 5%) of the flow to high pressure. Where they are appropriate they work very well...my brother in Maine has supplied his house for 45 years this way and it is like free money.

That's very interesting. Could you maybe post a diagram of how that works? (Or recruit your brother to draw the diagram...). Thanks

 

[hutchphd]

When he built it (1970's) I had never heard of such a thing and was suitably impressed by his engineering diligence (not bad for an MD!). They are decidedly not new, but are very clever. Now there are lots of good explanations online:


The downhill flow builds up until turbulence causes a flap valve to slam shut and it squirts the water hammer into a little local pressurized holding tank via a one way valve. Repeat.
He rebuilds it every couple of years and in between it just thumps away like a slightly metallic heartbeat in his little semi-underground spring house. His house tank is about 80 feet above the ram pump. Any overflow pumped waters the garden.

 

[sophiecentaur]

I searched this thread for the word "safety" and I couldn't find it. Has no one considered the energy that's stored in compressed air, even at moderate pressures? You have the choice between a small air reservoir at frighteningly high pressure or a larger one with still worrying pressure.

If there is enough room for a water tank then why not use the sort of pump(s) that can be bought in any plumbing supplier's. They have adjustable output pressure. When you leave the system and go home at night there's no problem with leaks and your average plumber can fix any problems.

 

[timMoore]

have you checked out any energy storage options to prevent the blackouts/brownouts? If you want to use compressed air and water there are a few energy storage options. how much energy does your resort use? I read about a new system which uses compressed air to blow out high pressure water through a pelton turbine to generate electricity. This would increase the value of your solar panels too by maximizing your overall consumption.

 

[berkeman]

Old thread paused for Moderation...

 

[berkeman]

Thread is reopened...

 

[sophiecentaur]

If you want to use compressed air and water there are a few energy storage options.

Compressing air always involves heating it up and that thermal energy is of the same order as the stored mechanical energy. For good efficiency, it would be necessary to insulate the stored high pressure air which would limit the time period it could be used for. Also, very high temperatures would be involved.

Whoops - I already made this point two years ago. well spotted, Mods!

 

[simpleengr]

I don't understand why everyone is stuck on the same basic perception, focusing on the how not the problem.

Use water to do the job. Use water in a bladder type action on top of the water being used, then when the water level gets low, transfer the water from the bladder into a side storage to remove the force being applied from above, then transfer the water that was in the bladder to the usage tank it had been applying pressure to, then either size those tanks so that they hold enough till pumps can fill the bladder up again, or manually fill it. No need for complex pneumatic systems or pumps.

But for dishes and hand washing, yes foot driven pneumatic pumps are simple and free from needing expensive pipelines and compressors with huge storage tanks.

 

[Tom.G]

I don't understand why everyone is stuck on the same basic perception, focusing on the how not the problem.

Use water to do the job. Use water in a bladder type action on top of the water being used, then when the water level gets low, transfer the water from the bladder into a side storage to remove the force being applied from above, then transfer the water that was in the bladder to the usage tank it had been applying pressure to, then either size those tanks so that they hold enough till pumps can fill the bladder up again, or manually fill it. No need for complex pneumatic systems or pumps.

But for dishes and hand washing, yes foot driven pneumatic pumps are simple and free from needing expensive pipelines and compressors with huge storage tanks.

How does that differ from gravity feed?... other than needing a bladder?

 

[Rive]

Use water in a bladder type action on top of the water being used, then when the water level gets low, transfer the water from the bladder into a side storage to remove the force being applied from above, then transfer the water that was in the bladder to the usage tank it had been applying pressure to, then either size those tanks so that they hold enough till pumps can fill the bladder up again, or manually fill it. No need for complex pneumatic systems or pumps.

Honestly, with all that 'transfer' it sounds like a really complicated steampunk fantasy about plenty of brass knobs'n'stuff.
With a decent misunderstanding about hydrostatic pressure around the part of 'force being applied from above'.

Could you please elaborate?