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Water vortex to eliminate rust in well water

  1. Feb 2, 2012 #1
    I am trying to find a way to eliminate rust in well water. I was wondering if a water vortex could separate the rust from the water. I have a 1" diameter flow at 35 to 50 PSI. Can I place the inlet at the bottom of a larger pipe(I do not what size would be optimum) to create a vortex and have the outlet in the middle at the top? Is this plausible? The rust is not dissolved, it is visible.
  2. jcsd
  3. Feb 2, 2012 #2


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    Just thinking out loud here... I would think it could work but you want to do an analysis to see. For the rust particles to settle out, you need to find what velocity they 'fall' through the water at and create a tank that allows water velocity to be below that velocity so the particles can drop faster than they are swept away with the flow.

    For example, you might model the particles as spheres. Once you measure the size (cross sectional area exposed to flow) and determine the volume and weight, you can calculate the downward force on the particle in water (archemedies principal), assume a drag coefficient, and then calculate the velocity needed for equilibrium. That's the velocity you need to keep the upward moving water below. Needless to say, you should add a 'safety factor' onto that velocity, perhaps cut it in half to ensure you have a reasonably good chance at getting most of the particles out.

    Or just stick a filter in there.
  4. Feb 2, 2012 #3
    I stuck a 20 micron filter in the line it seemed to have little effect. That is why I am looking for a no/low maintenance solution.
  5. Feb 2, 2012 #4


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    If the particles are that small, and without doing the math, I suspect trying to get them to settle out would require a tank the size of a swimming pool.
  6. Feb 2, 2012 #5
    I'm beginning to suspect that the flow has to be at a standstill. I'm also considering some very powerful magnets.
  7. Feb 4, 2012 #6


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    At this book you can see how to do those calculations - look for "just suspended speed" and "settling velocity" (P.550-564)
  8. Feb 4, 2012 #7
    Thank you I will check into it.
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