Gravity Mill - any comments to this idea?

[prajna]

tbird,
my approach is to get a rough idea of how something works and then work all of the details out for myself.  That means to ignore the manual completely and, though that might sound dumb, it means that I end up with a deep understanding of how something works - much deeper than if I had simply read about it.

I've updated the calculator a little.  Nothing significant changed but I have added a picture to make things a little clearer.
http://declarepeace.org.uk/energy/elsa.htm

maybe you just left out another step that would leave you with enough compress air.

I think I straightened this out in a recent posting:

At the bottom of the cycle air is released from the bottom of the shuttle (think of it as an upside-down hollow piston) into the pumping cylinder until the pressure is equal inside the shuttle and below it.

Aah, I see your confusion.  The displacement area is below the shuttle (not the reservoir inside the shuttle).  I let the air out of the displacement area but don't let out the air I have just pressurised into the reservoir.  Is that clearer?

[tbird]

tbird,
my approach is to get a rough idea of how something works and then work all of the details out for myself.  That means to ignore the manual completely and, though that might sound dumb, it means that I end up with a deep understanding of how something works - much deeper than if I had simply read about it.

I've updated the calculator a little.  Nothing significant changed but I have added a picture to make things a little clearer.
http://declarepeace.org.uk/energy/elsa.htm

maybe you just left out another step that would leave you with enough compress air.

I think I straightened this out in a recent posting:

At the bottom of the cycle air is released from the bottom of the shuttle (think of it as an upside-down hollow piston) into the pumping cylinder until the pressure is equal inside the shuttle and below it.

Aah, I see your confusion.  The displacement area is below the shuttle (not the reservoir inside the shuttle).  I let the air out of the displacement area but don't let out the air I have just pressurised into the reservoir.  Is that clearer?

had a short look again at your program.  with 15cm (+or-6inches) diameter and 30cm (+or-12inches) high (sounds like less than 1 cubic foot (64.7lbs)) the result is 53.01 kg.  doesn't that sound heavy to you?  maybe you need to use internal radius instead of internal diameter.

so there is a small passage outside the shuttle (still inside the tube) to valve 3?

your shuttle does get pretty close to elsa design.  if i see your shuttle right, the bottom of the tube will be open? to allow the shuttle to descend without moving water up threw exit pipe?

tbird

[ooandioo]

Aah, I see your confusion.  The displacement area is below the shuttle (not the reservoir inside the shuttle).  I let the air out of the displacement area but don't let out the air I have just pressurised into the reservoir.  Is that clearer?

Ok, now its much clearer and actually I think its the best design we currently have.

[prajna]

Guys, for the calculator the shuttle design is even simpler than the previous one.  Take a look at the picture on my calculator site.  It is just a hollow piston into which we can compress air.  At the bottom of the stroke the air is released from the piston (via a valve, presumably) underneath the piston.  This means that the compressed air that was inside the piston is now partly inside the piston and partly underneath it.  But now it has expanded from the volume of the piston (actually slightly less because we have to take into account the thickness of the piston's walls so its internal capacity is slightly less than its displacement) to the volume it will occupy at the depth we release it (10m in my default example).

Does this all make sense?

[prajna]

had a short look again at your program.  with 15cm (+or-6inches) diameter and 30cm (+or-12inches) high (sounds like less than 1 cubic foot (64.7lbs)) the result is 53.01 kg.  doesn't that sound heavy to you?  maybe you need to use internal radius instead of internal diameter.

It is heavy, tbird.  That is because you have a much taller shuttle than you need.  What kind of head are you lifting?  If it were 1kg (2.2 pounds, I think) then you would need a much smaller shuttle.  Tell me the head sizes as well as the pump sizes and I will tell you a reasonable shuttle height.

How much does one cubic foot of water weigh?