Re: Magnetocaloric & Pyromagnetic Effects

Norman Wootan ( normw@fastlane.net )
Thu, 16 Apr 1998 09:51:35 -0700

Jerry: I really enjoyed the meeting last night. About the "currie point"
discussion we had at the meeting and the magnetic caloric motor principle we
need to go back and review a few messages. Go to
#5989,norm;#6010,jerry;#6017,norm;#6025,Gerald O;and #6031,norm for we had
this discussion related to Floyd Sweet conditioning process for his barrium
ferrite magnets. On the caloric effect on the magnets, why heat the
magnets? If you heat any magnetic metal it will become diamagnetic when it
gets hot and goes back to magnetic attraction when it cools slightly. Try
this with any piece of steel attached to a magnetic. Heat the steel till it
glows red and it will fall off the magnet. Any good metals handbook will
tell you that iron or steel in a molten state is not magnetic or cannot be
magnetized. Now that the cat is out of the bag we will see an argument
arrise as to how the earth has magnetic poles since the core is supposed to
be molten iron??????? Some say it is the flowing molten metal that
generates "teluric currents of millions of amps that generate the magnetic
fields sort of like MHD. If I were you I would not waste time heating bulky
magnets and try cooling them at rapid rates when you can do the same effect
by heating and cooling thin steel strips very rapidly. Once this "currie
point" thing is well understood by all then we can develope a working
device. Remember that "Tesla" said that iron was an interesting element for
it is unique in the fact that it changes crystalline structure as it is
heated and cooled. He also said that the "M" shell electrons could be
bounced out to be used for power only to be replinished by the aether.
Mnnnnn! Norm

Jerry W. Decker wrote:

> Hi Folks!
>
> Anton Rager posted this to freenrg, it is directly in line with recent
> discussions here about pyromagnetics and such. Magnetocaloric is a
> phenomenon first described to me by Jack Veach. He said it used a very
> thick ceramic cylinder that surrounds an energy generator that puts off
> a lot of heat while producing current. A 'swept' magnetic field, moving
> from the inside (where it's very hot) to the outside, through the
> ceramic, will carry the heat with it.
> -----------------
> Hello All,
>
> New idea occurred to me while reading the latest [May 98] Scientific
> American. It's also online - see:
>
> http://www.scientificamerican.com/1998/0598issue/0598techbus5.html
> [it has a couple typos -- iron has a Curie closer to 770deg C]
>
> There is brief blurb about a new type of refridgerator that uses very
> strong magnetic fields [superconducting magnets] and the magnetocaloric
> effect as a heat exchanger. This idea by itself is somewhat
> interesting....but the coolest part [no pun intended] is that
> it uses Gadolinium for the magnetocaloric effect.
>
> I will assume that everyone else is just as ignorant as I am about
> magnetocaloric effect and properties of Gadolinium. If not....then
> ignore the following discussion.....
>
> 1 - Magnetocaloric Effect: magnetic fields applied to a ferromagnetic
> material will increase the temperature of the ferromagnetic material.
>
> 2 - Gadolinium: Ferromagnetic material [element] that has two very
> important properties.....
> - out of all the other ferromagnetic materials, it exibits the
> strongest magnetocaloric effect.
> - it's curie temperature is about room temperature [20deg C/68deg F]
>
> Now -- I have a few questions.
>
> - Can a static magnetic field [read - strong permananet magnet]
> applied to the ferromagnetic material induce a magnetocaloric
> effect...or does it need to be pulsed?
> - Any ideas on how strong a magnetic field needs to be applied to see
> the magnetocaloric effect? Is there a formula -- #degrees incease
> relative to applied field?
>
> Also have some prelim ideas.....
> - Perhaps a magnetic motor could utilize the magnetocaloric effect and
> Gadolinium's low Curie point...imagine a curved array of strong
> magnets as a stator, with Gadolinium nodes on the rotor.....as the
> rotor node passes thru the array, it heats up to the Curie point.
> This allows the rotor node to pass thru the strongest part of the
> array field and into a regauging area. It cools slightly in the
> reguage area, and then enters the magnetic array again. This would be
> an extremely temperamental system, but might work in my basement?
>
> Ahhhh......I just love free-associating! All for now,
> == Anton Rager - a_rager@yahoo.com
> --
> Jerry W. Decker / jdecker@keelynet.com
> http://keelynet.com / "From an Art to a Science"
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