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Using a container to pump water...


Externet

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Hi.  

Seen several contraptions shown in youtube videos that seem to pump somehow and a container works in partial vacuum.  There is maaaany videos doing the same in many styles.  Can someone explain what is going on ?

I dislike to send you to a particular link,  just search terms "water pump" within youtube for your own choice.   If you really want an example link, try

--->  https://www.youtube.com/watch?v=23Afu1ViH3E   and dozens appear at the side column.  They all use a container, and mostly asian construction.  Perhaps there is one in english.

 

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On 6/2/2024 at 3:34 AM, Externet said:

Hi.  

Seen several contraptions shown in youtube videos that seem to pump somehow and a container works in partial vacuum.  There is maaaany videos doing the same in many styles.  Can someone explain what is going on ?

I dislike to send you to a particular link,  just search terms "water pump" within youtube for your own choice.   If you really want an example link, try

--->  https://www.youtube.com/watch?v=23Afu1ViH3E   and dozens appear at the side column.  They all use a container, and mostly asian construction.  Perhaps there is one in english.

 

YouTube is full of shit. I suspect most of us have better things to do than trawl through it, looking for something that may or not be what you are talking about.

I had a quick look at the link you provided, but as ever there is no adequate description of what is being done. As I am not going to indulge in guesswork, that's the end of it for me.   

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Posted (edited)

This video gives much clearer details, math involved and their results from testing(it did not at their elevation).

 

My take is that it is supposed to exploit the difference in air pressure between the inlet and outlet. May be worth retesting at a lower elevation.

Edited by Endy0816
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29 minutes ago, Endy0816 said:

This video gives much clearer details, math involved and their results from testing(it did not at their elevation).

 

My take is that it is supposed to exploit the difference in air pressure between the inlet and outlet. May be worth retesting at a lower elevation.

This is very unclear indeed. The voiceover talks of Bernoulli, suggesting the principle is the suction from a partial vacuum created by a flow of water through a venturi. This is how the laboratory water aspirator, commonly used in suction filtration, works:   https://en.wikipedia.org/wiki/Vacuum_ejector

But that does not seem to be what is going on the YouTube video linked by @Externet, nor does this video of yours show any venturi, or indeed any source of the constant flow of water needed to sustain a  water aspirator. The maths is not shown. There is just one little formula flashed up for a couple of seconds, with no explanation. The design of the system is not shown either, so far as I can see. It's all hidden inside the barrel. One gets the impression this bunch in the video have no idea what they are doing, and indeed, mirabile dictu,  it doesn't work!  

This is all crap, by the look of it. 

 

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The situation on the left won’t work, since the water is going higher - you need to do work. It could work if there was sufficient flow, and you converted KE into PE. They mention this early on; it’s what happens in a ram pump.

The situation on the right is a siphon, with a reservoir in the middle. Water ends up at a lower PE, so there’s no need for work to be done. 

IMG_0761.jpeg

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The 'logic' seems to be that running water out of a sealed header tank creates a partial vacuum (true so far) that can be used to suck up water from a lower elevation than the discharge.

13 minutes ago, exchemist said:

This all crap, by the look of it. 

Seconded. Just another PM dream.

As for the ram pump idea, if the incoming velocity head was higher than the required lift, the flow would climb the bank of it's own accord.

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8 hours ago, sethoflagos said:

As for the ram pump idea, if the incoming velocity head was higher than the required lift, the flow would climb the bank of it's own accord.

Ram pumps work. They can elevate water above that of the velocity head, just not all the water contributing kinetic energy.

If velocity head was the maximum pressure harnessable by a water streams momentum, water hammer wouldn't be much of an issue.

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1 hour ago, J.C.MacSwell said:

Ram pumps work. They can elevate water above that of the velocity head, just not all the water contributing kinetic energy.

If velocity head was the maximum pressure harnessable by a water streams momentum, water hammer wouldn't be much of an issue.

Yes, I'm well aware of how ram pumps work.

But there was no ram pump in the system described, and therefore no means of channeling the input kinetic energy preferentially into the vertical output stream.

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17 hours ago, sethoflagos said:

The 'logic' seems to be that running water out of a sealed header tank creates a partial vacuum (true so far) that can be used to suck up water from a lower elevation than the discharge.

Seconded. Just another PM dream.

As for the ram pump idea, if the incoming velocity head was higher than the required lift, the flow would climb the bank of it's own accord.

Yes. From a purely energetic viewpoint one could imagine that a fall of 2kg of water through 0.5m would be enough to lift 0.5kg of water through 2m.  But the problem seems to me to be that the "suction" , i.e. pressure drop, generated in their setup is determined by the head of water in the container, which, being less than the head needed to draw the water up from the well, cannot possibly achieve that. I think they would need to put all the water in their container into a tall pipe, taller than the depth of the well, and let the suction from that, as it empties from the bottom, draw water up.  

Anyway the whole exercise is pointless as it relies on refilling a container with water to keep the thing going, as they have no running water source to sustain any of these ideas. So just typical YouTube crap.

 

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10 hours ago, sethoflagos said:

Yes, I'm well aware of how ram pumps work.

But there was no ram pump in the system described, and therefore no means of channeling the input kinetic energy preferentially into the vertical output stream.

Okay. I'm not sure what ram pump idea you were referring to, but it seemed you were implying their use was limited by velocity head.

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20 minutes ago, J.C.MacSwell said:

Okay. I'm not sure what ram pump idea you were referring to, but it seemed you were implying their use was limited by velocity head.

Just a poorly worded afterthought. I intended to say that in the absence of a ram pump or equivalent, the only driving force to hand is the velocity head of the source.

On the other hand a ram pump could use a waste flow head drop of a metre, say, to generate surge pulses of up to 15 bar or so albeit for a much lower flowrate.

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9 hours ago, sethoflagos said:

Just a poorly worded afterthought. I intended to say that in the absence of a ram pump or equivalent, the only driving force to hand is the velocity head of the source.

On the other hand a ram pump could use a waste flow head drop of a metre, say, to generate surge pulses of up to 15 bar or so albeit for a much lower flowrate.

Okay. Thanks for the clarification.

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