Author Topic: Using eddy currents for heating  (Read 5642 times)

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Amptramp

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Using eddy currents for heating
« on: January 12, 2006, 09:38:19 AM »
Howdy folks,


I wonder if this is a practical idea.

When testing my first axial flux generator in the lathe, I accidentally managed to heat a nearby aluminium plate to the point that I received a burn from it.


Well, once the pain subsided, I got to wondering about a good use for the eddy currents that had produced this effect.

Could it be used to heat water, by being driven directly from a wind turbine?


In my test setup, I was running 16 magnets on a 260mm steel disc at 400 RPM. By bringing an aluminium plate near to the spinning mass, I managed to slow the lathe down, and produce great quantities of heat in the plate.

Now, if a water vessel had an aluminium base, or perhaps another suitable metal, and the magnet rotor was spinning under it, the water inside would soon become quite hot.


Perhaps this has already been discussed, but I would love to know if other folks have tried this method.


Thanks kindly,

Steve Mc AmpTramp.

« Last Edit: January 12, 2006, 09:38:19 AM by (unknown) »

Norm

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Re: Using eddy currents for heating
« Reply #1 on: January 12, 2006, 05:10:03 AM »
  It's been noted and talked about ....one person

accidentally done this when trying to make a

stator plate of aluminum to hold the coils....

but I don't think anyone has actually tried it.

  Might work pretty well if the device is down on the ground ...like on a savonius?

                  ( :>) Norm

« Last Edit: January 12, 2006, 05:10:03 AM by Norm »

drdongle

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Re: Using eddy currents for heating
« Reply #2 on: January 12, 2006, 05:45:07 AM »
There was a thread about 18 months ago about such a heating system ( found else where on the net)which incorporated oil as a storage medium, apparently extravagant claims were made for its efficiency.
« Last Edit: January 12, 2006, 05:45:07 AM by drdongle »

electrondady1

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Re: Using eddy currents for heating
« Reply #3 on: January 12, 2006, 06:17:07 AM »
 last summer i posted an idea i had about using some 1/8" copper tubing as a coil. the idea was the eddy current heat would be transfered into a liquid  pumped through the tubing.
« Last Edit: January 12, 2006, 06:17:07 AM by electrondady1 »

finnsawyer

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Re: Using eddy currents for heating
« Reply #4 on: January 12, 2006, 08:40:49 AM »
You can also heat water by rotating paddles in it.  This eliminates the need for the alternator.  This may seem strange, but was the method used originally to show the equivalence between mechanical energy and heat energy.
« Last Edit: January 12, 2006, 08:40:49 AM by finnsawyer »

Arno

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Re: Using eddy currents for heating
« Reply #5 on: January 12, 2006, 12:17:07 PM »
    yo finsayer,


     That sounds great, do you think rotating paddles or fan might possibly do that in air?


arno

« Last Edit: January 12, 2006, 12:17:07 PM by Arno »

SmoggyTurnip

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Re: Using eddy currents for heating
« Reply #6 on: January 12, 2006, 03:13:36 PM »
Lots of electric stoves use eddy currents to produce heat on the stove top.
« Last Edit: January 12, 2006, 03:13:36 PM by SmoggyTurnip »

finnsawyer

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Re: Using eddy currents for heating
« Reply #7 on: January 13, 2006, 08:38:40 AM »
In theory, yes.  But to really see the effect you have to keep the air from moving or being circulated.  There is also the question of how much of the heating is from the fan motor or bearing resistance.  But still, heat is heat, I guess.  Water is superior because of its density and heat capacity, and you can easily keep it in one place.
« Last Edit: January 13, 2006, 08:38:40 AM by finnsawyer »

hotwired

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Re: Using eddy currents for heating
« Reply #8 on: January 19, 2006, 04:37:17 AM »
eddy current ? take 2 al discs place neo magnets evenly spaced around disc not touching, place one disc with neos glued to disc in round container of water place neos on other disc magnetically opposed place disc on 1750 or 3450 rpm electric motor shaft, before placing water in container adjust the spacing of magnets so the motor will start, the placing of neos on discs will need to be placed in attract repel mode the motor of course mounted vertical some sort of gadget needed to raise or lower the distance of the rotating disc to allow for the best magnetic and repulsion of neos after motor comes up to proper rpms suppose what the idea is to make and break a magnetic field umpteen times per rpm after doing this switch from water to very thin oil see difference in heat output,this will make heat but do not know of any real use for it.You cannot get more out than you put in, old energy law. have fun  
« Last Edit: January 19, 2006, 04:37:17 AM by hotwired »

Amptramp

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Re: Using eddy currents for heating
« Reply #9 on: January 21, 2006, 04:54:17 PM »
Howdy Electrondady1


There have been some good ideas offered here. The idea of a coiled copper tube is quite an interesting one. It gets around some obvious problems in my original idea, and ought to be fairly easy to try.


My biggest windmill is pretty grunty. Quite a few Horse power of energy is available at the downshaft. Presently, this energy is being used to make electricity and compressed air. I figure that some of it can be used to heat water with eddy currency.


Hey, it's worth a try  :)  .


Oh, how I love tinkering.


Best wishes,

Steve Mc Amptramp.

« Last Edit: January 21, 2006, 04:54:17 PM by Amptramp »

Rst

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Re: Using eddy currents for heating
« Reply #10 on: August 31, 2006, 10:14:31 PM »
I have make some tests with magnets and a plate of aluminium of 12 inch at 1750 rpm with 2 hp motor and the plate heat at 654 F, but it is very difficult to spin it.


Troy Reed use the same, but it says that is too easy heat or not.


can you help me?

« Last Edit: August 31, 2006, 10:14:31 PM by Rst »