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Water desalition: Verify request to new Idea for desalination

  1. Jan 20, 2012 #1
    Greetings friends,

    I have a new idea for desalinating water but I am not good at physics. My idea may sound stupid and if so I am sorry for that in advance but please could you have a look. I am attaching the image to this post which will try to explain the simple idea to generate pressure for desalination.

    I request if someone could verify if this idea could really work.

  2. jcsd
  3. Jan 20, 2012 #2

    Simon Bridge

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    The "new" bit I guess is the use of a thermally expanding fluid in a pipe to apply pressure for reverse osmosis?

    You need it's thermal expansion to also be much bigger than that of the pipe, and remember that the fluid will exert pressure on the pipe as well.

    What you are describing is a thermal expansion pump.
    Better picture would have the bulk of the fluid in a ball heated and cooled periodically forcing the liquid in and out of a tube. A valve system means that sea-water is sucked in during the contraction and then pushed against a reverse osmosis filter during the expansion.

    The main problem will be doing this in industrial quantities ... afaik, these pumps are only good at very small flow rates because of how slow the expansion usually is, and they tend to be expensive to build.

    But I don't think it violates any physical laws or anything.
    The energy comes from the Sun.

    I suspect you are better off using a solar-cell driven electric pump.
  4. Jan 21, 2012 #3
    thank you very much for your reply ... yes I am sorry for my ignorance ... I just thought I would share what I had in mind in case there is a possibility of it being useful ... yes the idea was to use solar energy (heat from it) and using the alternating nature of the ocean tides for the cool effect during the day and the heating effect during the night. But it doesn't seem feasible. Thank you for analyzing this. :) Wish you a nice day!
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