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.
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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" Voice : (214) 324-8741 / FAX : (214) 324-3501 KeelyNet - PO BOX 870716 - Mesquite - Republic of Texas - 75187