Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Could this be possible? water underground

  1. Jun 18, 2015 #1
    Good day everyone, i need your help if you could please give me your opinion.

    I have some question, if the tube being suctioned could it lift the water underground?

    Could it able to sustain the flow of water in the tube, by just its own pull continuously?

    I know it sound crazy you, do you think this is possible? TIA
     

    Attached Files:

  2. jcsd
  3. Jun 18, 2015 #2

    Dale

    Staff: Mentor

    Sure. This is how many wells work.
     
  4. Jun 18, 2015 #3
    This is the principle utilised by bore wells all over the world. Nothing crazy about it.
     
  5. Jun 18, 2015 #4

    russ_watters

    User Avatar

    Staff: Mentor

    Note though that the suction head is limited to about 10m by air pressure (minimum vacuum). Larger wells need the pump at the bottom.
     
  6. Jun 18, 2015 #5
    Russ i thought about this too but I'm not sure if the atmospheric pressure is directly or continuously acting on the water table. Maybe it would be much less than 10m head. Any insights?
     
  7. Jun 18, 2015 #6
    I would think it is more. Certainly the pressure in the earth is higher than the pressure in the atmosphere.
     
  8. Jun 18, 2015 #7
    That pressure has already been utilised when the well has filled up naturally to a certain height. It's about the additional pump required to pump it from that free surface depth.
     
  9. Jun 18, 2015 #8

    russ_watters

    User Avatar

    Staff: Mentor

    You are both potentially correct. It depends on the geology if the water is under additional pressure or not. That's what happens with springs and artesian wells, not to mention oil gushers.

    But for the typical open-above well, with a pipe that does not seal the well sides, the height is referenced from the water level and the head referenced to atmopheric.
     
  10. Jun 18, 2015 #9
    thanks again
     
  11. Jun 18, 2015 #10
    any suggestion guys? if this 10 m air space in tank, could vacuum the water from under ground, if i let open the valve? could it carry water from the ground up to the water tank? since the water in the tank has pressure to suction the water under ground. correct me if am wrong :) :) :)

    TIA :) Screen Shot 2015-06-18 at 10.59.35 PM.png
     
  12. Jun 18, 2015 #11

    Dale

    Staff: Mentor

    10 m is about the maximum. It would require vacuum in the tank instead of atmospheric pressure.
     
    Last edited: Jun 18, 2015
  13. Jun 18, 2015 #12

    anorlunda

    User Avatar
    Science Advisor
    Gold Member

    The 10 m limit comes because the water at the bottom will begin to boil if the absolute pressure approaches 0 PSIA.
     
  14. Jun 18, 2015 #13
    No. What you're proposing would be a perpetual motion machine. Look at the pressures in the tank and the riser from the ground and convince yourself that it is not possible.
     
  15. Jun 18, 2015 #14
    Yes. The pressure at the water table, of course, is 1 atm.

    Chet
     
  16. Jun 18, 2015 #15
    10m is the theoretical limit at 1atm. Practically vapour locking will cause a loss of suction much earlier. Think maybe 7m in reality.
    Though I'm getting the suspicion you are after a perpetual motion machine.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook