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Steam driven brushless DC generator - would this idea work?

  1. Aug 14, 2009 #1
    Hi fellow thinkers.
    I need constuctive criticism on the following:-
    Imagine a tube circling around into a closed loop - like a hoop. Inside the hoop is a ring of connected bar magnets all facing the same way. Pressurized steam is fed into the hoop - and exited in such a way as to spin the independent magnet assembly ring. The magnet assembly ring is designed in such a way that as it reaches high RPM it "floats" inside the hoop, and therefore operates with little or no friction. At intervals around the hoop, wire is coiled. These coils are connected in series or in parallel - I'm not sure which is best?

    Is there anything fundamentally wrong with this concept?

    I came up with this idea all on my own:smile:, but would not be surprised if somebody has already invented or patented a similar concept. If this is an original idea, my wish is for it to be opened to the public forum, and availabe to all.

    Here are my concerns:
    For the sake of discussion, let there be four magnets 90 degrees apart in the floating ring, and let there be 5 coils 72 degrees apart on the hoop.
    (1) In one revolution, there would be 20 individual instances of induced EMF. Would these inductions interfere with each other or cause impedence - as they all share the same circuit.
    (2) Since we are dealing with high temperatures and pressures, I was thinking of using brass for the hoop, and using brass for the ring assembly in which the bar magnets are embedded. Would brass diminish the electromagnetic fields?

    Any other comments or considerations on this model are welcomed.

  2. jcsd
  3. Aug 14, 2009 #2


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    Welcome to PF, Leon.
    I can't speak to the electrical aspects of it, but it definitely won't be a 'free-floating' or frictionless magnet train. Conservation of angular momentum will make it want to continue in a straight line, so it will be constantly scraping against the interior of the hoop in order to change direction. There will be huge frictional losses, and abrasion of material.
    That's the best that I've got right now. I've had only a dozen beers, and am too tired to have enough more to reach my optimal thinking potential. Besides, there's a woman downstairs waiting for her birthday goose.
    I'll leave the rest of the responses to the experts.
  4. Aug 14, 2009 #3
    In reply to Danger
    Hi and thanks for the welcome
    Yeah, already thought of the centrifugal force. Possible solution; - the little bullet shaped bar magnets are slot into a fabricated solid ring structure that rotates inside the hoop space. Sort of like a miniture carousel that carries the magnets, and has aerodynamic surfaces and flaps to catch the passing steam.

    edit: The magnets could be disk shaped and therefore serve as flaps too.
    Last edited: Aug 14, 2009
  5. Aug 14, 2009 #4


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    How is this any better then a standard generator?
  6. Aug 14, 2009 #5
    Replying to Integral
    If this concept works, it will replace a steam turbine / DC generator combo. It will have only one moving part. No brushes. No bushes or bearings.
  7. Aug 14, 2009 #6


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    I think your idea is basically just a simplified turbine. It might work, but it would be highly inefficient. You wouldn't be able to extract all of the useful energy from the steam with such a setup.
  8. Aug 14, 2009 #7
    You would need to place the magnets North, South, North and South. Using the wiring configuration of 5 conductors 72 degrees could work if the breadth of the magnets spanned each wire of the rotor when it passes and being wound correctly and brushes placed correctly. I think copper is the best due to it's characteristics but brass may work but may need cleaned periodically.
  9. Aug 15, 2009 #8
    Hi QuantumPion.
    Yeah, I think you have made a fair statement. Maybe if the steam was introduced as a finely nozzled stream against the vanes of the "carousel", it would have a chance to decompress and cool/contract significantly before exiting the loop. I admit, the steam would have to do all its effective work in about 250 degrees of its progress around the "hoop".

    Responding to Philosophaie.
    Hi. Don't think you understand my concept. Please re-read first post in thread. The magnets move around inside the "hoop" pipe, and are oriented so that all Norths point clockwise (or all point anticlockwise). Now wire is coiled around the outside of this hoop - so the coils are stationary - and the magnets move inside - opposite to convention. No need for brushes at all, the coils are hardwired to each other in either series or parallel.

    This model is unlike a conventional dc genie because the magnetic fields interact with coils in a different manner.

    edit: "wire is coiled around the outside of this hoop" - I mean like same concept as if you coiled wire around an empty toilet roll and dropped a bar magnet through it - - but that toilet roll is like a segment of the hoop
    Last edited: Aug 15, 2009
  10. Aug 15, 2009 #9
    I see your Idea. You are proposing a reversal of a fixed stator and movable rotor. First, magnets are on the rotor. Without propulsion the magnets would spin as the brushes do on the stator. With propulsion the stator should generate emf due to the spinning magnets.
    Last edited: Aug 15, 2009
  11. Aug 17, 2009 #10
    Hi peoples

    Forgive me for giving this concept just one more plug. I still believe in it. It hinges on two basic presumptions:
    1) It is possible to design a "floating" magnets/vanes ring structure that will efficiently harness energy of steam as it is spun inside a "toroidal" space. I realise now that at least two opposing jets of steam will be needed to cancel out net force against the "ring". The design I have in mind will have four injections of steam - one pair 180 degrees from the other pair - and will need four evacuating portals to be in symmetry. The steam will be required to do all of it's effective work while progressing only about 135 degrees around the loop.

    2) At present I see no problems with the electrics side of this concept. Nobody has supplied any objections. The magnets movement should induce current flow in the "toroidal coil" - which should be very smooth indeed.

    On this second point especially, I am hoping to hear some feed-back for or against.

    Thank you for your patience
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