Heat Seals

[TheCreator]

I'm making a chamber to boil off some Cadmium that is used for brazing silver contacts onto other metals.

I UNDERSTAND THE RISKS IN DOING THIS.

The amount of Cd is upto 12%, a very small amount, I've a few of these contacts and intend to do them in small batches.
The max temperature reached will be 500 degrees Celsius.

Here is a side view of my heating chamber (made from Iron), it is oval.
You can see how I've got several sealing lips. The grey dots are Alumium sealing rings which have been fitted into a groove (also visible) in the lip. My air gap will be ~0.5mm which I hope will close up once the chamber is heated.
Do I have too many lips, is it overkill? Do I need the Al seals?

The other graphic is the top exit for the gaseous Cd, with a Heat resistant glass tube (taken from a milking machine).
This tube will be surrounded by a water cooling system, to solidify the Cd.
Do you have any issues with this design?

 

[MikeHalloran]

I know nothing of stills for metals, so hum a few bars and I'll fake it. ;-)

I did not realize milking machines reached temperatures high enough to require heat resistant glass.

Glass is not real resistant to tensile stress so I'd worry about your aluminum sealing ring fracturing the glass.

Or is 'Alumium' a material distinct from Aluminum?

I wouldn't worry much about a cooling jacket around the glass, since that should put the glass in compression.

Will the condensing cadmium just stick to the glass surface of your condenser bore?
Or is that what you want?

Are you trying to recover the cadmium, the silver, or the other metals in the relay structure, or the other metals alloyed with the cadmium?




Mike Halloran
Pembroke Pines, FL, USA