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Move that water!

  1. Aug 12, 2004 #1
    [SOLVED] Move that water!

    Firstly g'day all, just had a glance through some of the topics and this seems like a fine forum.

    Some of you may be able to help me with a little problem I've been juggling in my head for a couple of weeks.

    Say I had a 1000 litre tank of water say one metre above the ground. At the bottom of the tank I have an outlet coming out the side of the tank, for instance a 50 mill PVC pipe.

    Now, the problem I'm trying to overcome is, if I wanted to move as much of this water as possible to a higher location (higher than the outlet) into an inlet which is level with the top of the tank and about 2 metres away in horizontal distance, without using any additional energy except for the potential energy already in the tank and without the use of a syphon or pump or outside energy of any kind, how would I go about this?

    Looking at it, to me logically, any pipe I connect to the outlet and up, well, I would only be able to get the water through the pressure in the tank , to the level of the top of the water. But I need it to go into the inlet which faces the tank but only the bottom lip of the inlet in level with the top of the tank.

    I would usually be in the philosophical parts of this forum so am not quite the techincal man. Hopefully I've explained it clearly but if I haven't then say so and I'll try and whip up the scenario in paint or something.

    Cheers!
     
  2. jcsd
  3. Aug 12, 2004 #2

    brewnog

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    A picture would be good here! If you're trying to raise any water above the level that is at the surface of the water in the supply tank, you will need more than just a pipe. Perhaps a gravity pump would help? But yes, post a picture.
     
  4. Aug 12, 2004 #3
    Won't work.
    The waterlevel in the tank it the same hight as the bottom of the target tank.
    It would only level out ti'll the level is equal in the source tank and the target tank.
    So in practice tou would probably only succede in getting a layer of about a cm in the target tank before the levels are in balance, that or nothing at all.
     
  5. Aug 12, 2004 #4

    brewnog

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    But you *could* try a gravity pump!
     
  6. Aug 12, 2004 #5

    russ_watters

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    With a siphon, you can lift the water higher than the level of the top of the water in the first tank (to get it over the top of the tank, for example) as long as it ends up below the level at the end of the hose. The final result is that you can't get the level in the second tank to be higher than the level in the 1st.
     
  7. Aug 12, 2004 #6
    It doesn't matter: even using a siphon he can't go above the level of the top of the water in the first tank.

    If he could, then he could repeat this process whith a third tank, and so on...
     
  8. Aug 12, 2004 #7
    This could work, if he doesn't need to move it fast, and he can get enough drop before the rise.


    Gravity Pump
     
  9. Aug 14, 2004 #8

    russ_watters

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    No, with a siphon, you can make the water go up - it just has to end up below the level of the water in the first tank. That's what a siphon is - its how you can siphon gas up and out of a gas tank.
     
  10. Aug 14, 2004 #9
    I don't care whether the siphon can go as high as I want, since the water inside it is useless for anyone. The point is how to get usable water (outside any siphons) in a second tank above the first one.
    And the truth is: using a siphon you can get water above the bottom of the first tank, of course, but you will never get any water above the level of the first tank.
     
    Last edited: Aug 15, 2004
  11. Aug 15, 2004 #10

    russ_watters

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    Well, its useful if you're trying to steal gas from someone: the only other way to do with without a pump would be to flip the car upside down.
     
  12. Aug 15, 2004 #11
    I don't see how your car could use the fuel while it is INSIDE the siphon...

    As I told you before, the point is how to get USABLE water (OUTSIDE any siphons) in a second tank above the first one.

    And, once more, the truth is: using a siphon you can get water above the bottom of the first tank, of course, but you will NEVER get any water ABOVE THE LEVEL of the first tank.
     
  13. Aug 15, 2004 #12

    russ_watters

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    Fuel travels up and out of the gas tank through the siphon, then down into the container you are collecting it in. To make it work, the end of the siphon the gas comes out has to be lower than the level of gas in the car's tank. Look HERE and HERE
     
  14. Aug 16, 2004 #13

    brewnog

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    Yes, but the container you're collecting it in can't be higher than your fuel tank!
     
  15. Aug 16, 2004 #14
    It is so even a syphon won't work.
    In other words nothing will work, at least nothing that doesn't use external power to move the water.
    Lik i said, the water will fill the pipe and stay there because the filling of the pipe will definately lower the waterlevel below the bottom of the second container.
     
  16. Aug 16, 2004 #15
    This is not a true statement. A gravity pump can move water to a higher point than the bottom of the water level without external power (except the kinetic energy of falling water). This is not against the laws of physics. It does it by using the falling water to move a little water to a higher point. They are highly inefficent (move only a small portion of the water that is dropped to a higher point), slow and waste water, but they can move water to a higher plane without external power. This is not psuedo-science, they are in use.
     
  17. Aug 16, 2004 #16
    Ok but that would require you to dump the water used to move the pump.
    (same principle is used to boost the pressure in air tanks when there isn't a compressor around with suffcient capacity).
    I did not take wasting water in my reasoning.

    But your right, with sacreficing water you could be able to get some water in the 2nd tank.
     
  18. Aug 16, 2004 #17
    You are missing the most important: the level of the water at the second tank will NEVER be higher than the level at the first tank.
    Take a careful look at THERE.

    Again, the truth is: using a siphon you can get water above the bottom of the first tank, but you will NEVER get any water ABOVE THE LEVEL of the first tank.

    I'm afraid you don't believe in this.
     
    Last edited: Aug 16, 2004
  19. Aug 16, 2004 #18
    As has been stated by several people already.
     
  20. Aug 16, 2004 #19

    russ_watters

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    ...including me. Rogerio, it just seemed to me like you didn't understand what a siphon does. Its a small issue though, especially since it won't help with the problem posted at the beginning of the thread.
     
  21. Aug 16, 2004 #20
    Oh, no! I'd had the same impression of you, russ_watters !
    :-)
     
  22. Aug 16, 2004 #21
    G'day all, sorry I haven't been back, but thanks for the big response. I'm on a different account because of a few techincal difficulties.

    Just letting you all know, I still am interested in this. Perhaps if I post up a diagram you'll better envisage what I'm doing. Also, I want to do it in a short time, just getting as much water over as I can in 20 secondsish. The amount of waste water is not an issue.

    I'll get around to doing the diagram tonight or tomorrow- sorry I'm heaps short on time at the moment.

    The gravity pump looks good, but I'm not looking to spend that sort of money. Just the basic stuff I can get perhaps at the hardware warehouse.

    Cheers.
     
  23. Aug 17, 2004 #22

    brewnog

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    There are essentially two ways to overcome your problem.

    The first is the aforementioned gravity pump. Once again, this is an inefficient, but viable method of raising a relatively small amount of water through a height. As has been established, siphons *will not* work for your application if water needs to end up at a higher point it started from. (Yes, we know how siphons work, and no, they can't supply water at a greater height).

    The second is a powered pump you would be able to get at the hardware warehouse. If this is some kind of school project, the chances are they want you to build a crude gravity pump. There are few practical applications of gravity pumps. If you simply want to fill a higher tank, you can buy a small electric water pump for a few quid.

    The only other thing I can think of is to use a sealed primary (lower) tank, and pressurise it.
     
  24. Aug 17, 2004 #23
    @brewnog

    Again this is external power.
    The challenge at hand is to NOT use external power.
    Pressurising the first container would work for sure, it woul become a giant supersoaker.
    Using pressure you'd be able to get the first container empty in just a few seconds, and depending on the pressure even quicker.
     
  25. Aug 17, 2004 #24

    brewnog

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    If the challenge is to only use the potential energy held within the supply tank, and both tanks are at the same pressure, the only solution is the gravity pump after all. And if it *is* some kind of school challenge project, you can have fun making one!
     
  26. Aug 17, 2004 #25
    and if you can use pressure, check what pressure the container can withstand.
    It would be fun to get around 2000 psi or higher behind it :surprise: :biggrin:
    Than the challenge would be to keep it in the second container :tongue2:

    N E way, good luck, and let us know how it turned out.
     
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