There is a classical engineering solution to this need, which is
guaranteed to be leak proof.
Place a primary winding on the ouside of the container, tightly
coupled to a secondary winding inside the container.
The coils axis points though the container wall.
Either coil can rotate on this axis with no effect on coupling.
You will say, I expect that the high current is in fact DC.
You *could* invert it however.
Brian Whatcott Altus OK
Brian,
Thanks for reply
But i need only to be able rotate feedthrough which is watercooled.
System such you mention will induce the current also on chamber wall
No winding outside, there is only ac current
Thanks
Pierre
wrote:
Do you *have* to transfer current through the same feedthrough you transfer
angular rotation? Couldn't you commutate it inside the chamber? Forgive
me if this is a naive question...
David A. Smith
Dear David,
Inside the chamber , i need to rotate the induction coil for pouring the
molten metal.
same induction coil requires high current 200 amp. @ 250 volt thus must be
cooled to avoid overheating damages.
So I have to transfer the current, water and rotary motion on the same axis
and keep the vacuum integrity.
Such systems exists, for vacuum induction melting furnaces but cost a lot of
money
May be I need to use high conductivity water cooled FLEXIBLE copper tubing
than keep the feedthtough fixed ??
Pierre
le message de
be
axis
of
tubing
Copper has no fatigue strength, so you'd have to replace it every few
cycles.
Do you have a sketch you could post a link to, that shows what you are
trying to do? Maybe it would trigger something in the "amassed minds"
here.
David A. Smith
Dar mkson:
with the appropriate substitutions from either of
headers below
"N:dlzc D:aol T:com (dlzc)"
<N: dlzc1 D:cox T:ne
(don't want to make it too easy for spammer bots to decipher.)
When I get it, I will post it on webspace for a couple of weeks, so the
crew here can take a gander.
David A. Smith
A vacuum container wall does not have to be conductive!
You didn't like that one? There is another classical engineering
response.
Visualize a fixed conductor entry which is capable of looping to the
far side of the rotating piece, in line with its axis of rotation.
As the piece rotates, the conductor loops around in the opposite
direction to that in which the rotor moves.
Brian W
Dear Brian,
Vacuum container is 300 series steel thus conductor.
I could not visualize, what you means, is it possible that you send me a
sketch or link.?
"fixed conductor entry capable of looping" : You means flexible conductors
attached able to have a torsion. ?
Thanks
Pierre
wrote:
http://members.aol.com/dlzc/feedthrough.jpeg
... in case someone has bright ideas on how to accomplish this task.
(I'll host the image for a bit...)
David A. Smith
It took a while to visualize it, but the optimal solution is quite
straight-forward.
Arrange a fixed entry into the chamber for the water-cooling and
electrical supply. This could be for example, a copper co-axial tube,
with water in the interelectrode gap. This can be absolutely vacuum
tight.
INSIDE the chamber, arrange flexible leads to depart the tube end
radially. At least two for power, at least two for coolant.
Fix a stub to the rotating crucible, axially aligned with the entrance
stub. Arrange the leads from the entry stub tube to loop back and
enter this internal roating stub tube axially.
When the crucible rotates, the loops all move slightly, to
accommmodate the rotation.
No sweat!
Brian W
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