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# Deep-submerged Vacuum Power

Vacuum Power at the Ocean Bottom
 (+3, -7) [vote for, against]

For deep-diving submersibles, a new power source. Simply build a very strong bottle, attach a special hydraulic pump as the valve, and send it to the bottom of the ocean with nothing in the bottle. When the outside pressure is incredibly strong, allow water to enter the bottle through the valve/pump. The volume of flow would have to be limited, but the torque/pressure would be incredible. The power would be extracted as a hydraulic pump, or maybe as electricity if a proper generator could be developed.
 — baconbrain, Jun 04 2006

Vacuum Energy Vacuum_20Energy
Like so? [ldischler, Jun 04 2006]

Kind of totally different http://blogs.spectr...driven_robotic.html
[loonquawl, May 25 2009]

you are going to consume energy getting the bouyant tank to the bottom, and its a one shot deal. But is a curious concept.
 — jhomrighaus, Jun 04 2006

 I haven't the math skills to guess how much energy will be involved. I think it might be equal to dropping the weight of the water that enters the tank to the depth of the sea-bottom.

 I figure that the empty tank might require some ballast to lower it, and the full tank could be dropped with the other ballast before returning to the surface.

Yes, it's a one-shot deal. Otherwise it's similar to the first part of Ldischler's Vacuum Energy idea. I searched the Halfbakery but didn't find that one--thank you for pointing it out. I'll leave this one in this category, and leave it up. That was intended to be a powerplant, I think. This one is a hydraulic power source for a submersible.
 — baconbrain, Jun 04 2006

Submersibles rock.
 — epicproblem, Jun 04 2006

//Submersibles rock.//
But only if you have stabilisation problems...

//I think it might be equal to dropping the weight of the water that enters the tank to the depth of the sea-bottom.//
Yes, compare when the empty tank is just below the surface, to when it is at the bottom. The water which is displaced is moved from the bottom to the top.
Quick reckoning: A one cubic metre tank which is 100m down could potentially give 1kW for 16 minutes (but efficiency would most likely be 30%).
After use, it needs to be hoisted up (a tank that could withstand the pressure would be expensive), and all the energy is put back into the system by the hoist motor...
 — Ling, Jun 06 2006

Not to mention the energy used to make the tank and haul it into position.
 — egbert, Jun 06 2006

It's official. This idea has tanked.
 — methinksnot, Jun 06 2006

 I disagree. Good pun, though.

 The tank could be cast fairly cheaply, as a sphere over a sand core. The material could be lead or iron, both of which used to be used for disposable ballast. The weight is not an issue, as the ballast will be discarded. The tank can have a smooth-machined face around the inlet, the valve will be held in place by the outside pressure, allowing easy discarding.

The idea is not intended to be used for submersibles on hoisting cables . . . hmm, I didn't say that, did I? I guess I was making assumptions about what people would assume. Okay, I'll see if I can do some revising and clarifying.
 — baconbrain, Jun 06 2006

 If the tank is weighted so it sinks on its own and is ideally efficient, the amount of energy you get exactly equals the energy needed to haul it back to the surface.

Just drop weights, hooked onto cables which are hooked onto generators, off a boat.
 — sninctown, Jun 06 2006

// It's official. This idea has tanked. // But it does hold water...
 — MoreCowbell, Jun 06 2006

 This idea got dinged when I first posted it, as a lot of folks seemed to think that I was proposing an energy source of some sort. Now, with a broken pipeline spewing oil on the bottom of the Gulf of Mexico, I'm annotating with an example of what I mean/meant.

 Take a hydraulic cylinder (make it big and beefy), and put a pinching device on the end of the ram. Retract the ram, suck all the air out, close all valves, and drop the thing into the ocean, with enough weight to carry it to the bottom. Position the pinching device over the pipe, and open the back valve. The pressure of the ocean WILL drive the ram forward, pinching the pipe shut (if the pipe is pinchable, I mean).

 The pressure on the ram will be proportional to the area of the piston. The available energy will be equal to dropping a cylinder's worth of water to that depth (something I first understood here on the HB, thanks).

 Then, once pinched, the cylinder is dead, useless and discarded. It is not hoisted back up to generate power.

The idea is simply to have a one-shot pincher, puncher or slicer with a lot of power and only a few moving parts. Which would be handy for dealing with a busted pipe on the bottom of the ocean.
 — baconbrain, Jun 21 2010

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