Impossible machine?

[GORDON]

I had a person say this to me recently:

"My basement is ready for a flood, because I have a pump that is driven by water pressure. For every 1 gallon that flows through that overflow into the basement, 2 gallons get pumped out of the basement."

That's impossible, right? I told him that sounds like a perpetual motion machine, but he responded like, 'no... what... you never heard of that kind of pump? it's no big deal.'

[Malcolm]

From here. He's probably cheating and using gravity.



Edited By Malcolm on 1360273271

[GORDON]

I've never heard of a hydrolic ram pump. This still seems impossible to me. If we can make water flow uphill with no added energy, then we should be completely energy independent because we can just freely pump a billion gallons of water up a mountain every day and let it fall through turbines and let it generate electricity before we make it flow uphill again for free.



Edited By GORDON on 1360275962

[thibodeaux]

less water flows out than in.

[GORDON]

Well that isn't what he told me, he told me 2 gallons pumped out for every gallon that flows into his basement.

[GORDON]

Unless he meant a flood of, say, 3 feet deep, and the water is getting pumped out a foot below the intake. But even then the outlet would need to be above the waterline, which we just determined was a foot higher than the outflow.

[Malcolm]

Here. I don't know how to break this down further without involving actual math.

A typical efficiency is 60%, but up to 80% is possible

Edited By Malcolm on 1360281429

[TPRJones]

Yeah, it's not what I would use for a flooded basement. You need a reasonable pressure on the input flow to make it work, and almost half of the water will slop out through the waste valve.

My grandfather's house had one of these. The house was almost as high as the water tower that fed it, and this method supplied water to the second story under good pressure with the "waste" water feeding the lower floor. But it was loud.

[GORDON]

Here. I don't know how to break this down further without involving actual math.

A typical efficiency is 60%, but up to 80% is possible

I get that a portion of the water can be moved higher than the source. I am saying 1 gallon in/2 gallons out is impossible, I just didn't want to argue with the guy because I didn't really care that much.

[thibodeaux]

http://xkcd.com/386/

[GORDON]

Bumping this for Leisher.

$300 gets you a good quality battery backup that doesn't rely on voodoo to work.

As long as you already have the crock.

[Leisher]

I'll do you one better...

I've already got the water driven pump and a plumper friend swears by it.

I'll also get a battery backup for my primary pump.

[Malcolm]

I've already got the water driven pump and a plumper friend swears by it.

Plumper than whom?

[Leisher]

I can't even make a funny to correct the typo because the guy is thin as a rail.