Sciencemadness Discussion Board

Copper Retort

If_6_was_9 - 28-3-2004 at 17:32

I polished up what seems to have been an old autoclave or bomb and converted it into a metal retort. Here's before and after pics (before and after polishing). I replaced the lead gasket with a rubber one. Some of the bolts broke when taking them out so I used the one's I had left in the second picture.








[Edited on 29-3-2004 by If_6_was_9]

[Edited on 29-3-2004 by If_6_was_9]

pressure rating?

Magpie - 28-3-2004 at 21:08

That is a most interesting piece of equipment. You say it is a bomb or autoclave. Does it have a pressure rating or any other information stamped on it? Ususally pressure vessels have such stampings.

If_6_was_9 - 29-3-2004 at 14:48

There's nothing written on it. I put the tubing on it (right side of the picture). There was a fitting there before. It looks like it was hand made out of several layers of sheet copper (or alloy?) welded together. It was in the 'old medical' section on Ebay. The lead gasket looks like it could be a problem at high temperatures so I replaced it with a rubber gasket.

[Edited on 29-3-2004 by If_6_was_9]

axehandle - 29-3-2004 at 17:04

Very interesting. I wonder why someone would construct a high pressure container out of copper, of all things. Copper has an abysmal tensile strength.

Perhaps because of its (as compared to mild steel) inertness, and because of its excellent heat transfer properties?

Have you got any idea how old it is?

[Edited on 2004-3-30 by axehandle]

chemoleo - 29-3-2004 at 17:10

Hmm.
Well, how about the whisky etc brewing people? I think they all use copper retorts, albeit much much bigger. maybe this was some DIY version.

axehandle - 29-3-2004 at 17:26

That's a reasonable assumption, but it doesn't explain all those bolts. The pressure in a whisky still is basically the same as outside it.

This copper..... *thing*.... baffles me......

chemoleo - 29-3-2004 at 17:49

how about distilling lovely things such as phosphorous? Mercury?
It could be used for a LOT of things.
nonetheless, i guess u have a point. This thing is meant to hold pressure. The copper thickness looks to be around 5 mm. Very thick. On the other hand, the engineer/machinist might have thought, better safe then sorry. If_6-was_9, did you see any device/valve that'd suggest that a high pressure is maintained during the reaction?
Also, it looks fairly professional, I have a feeling it was a proper piece of equipment in a lab at some point. Lead... also very inert. Can't be a coincidence!

BromicAcid - 29-3-2004 at 18:40

I think that distilling phosphorus in copper would be bad. I hear that it easily forms the phosphide. I know it's a terrible problem in iron but I think copper might even be worse. Be carefull of the clean up though, lots of fun phosphine.

gasket material

Magpie - 29-3-2004 at 20:32

A lead gasket - now that is interesting. I would have thought it would have been made of asbestos for high temperature and inert use.

You are using rubber. If you find that this will not hold up under high temperature use consider using a gasket made by Flexitalic. These are spiral wound carbon/metal. There are several metals to choose from. The bolt torque spec for sealing will be higher than for rubber, however. For rubber Viton is hard to beat for all around high temperature, chemical inertness, and economy.

Organikum - 30-3-2004 at 01:31

To me this looks like a part of an ancient steam-engine and the lead gasket speaks for this too.
In these old days copper was widely used as steel was hard to work with and cast iron was inherently dangerous for the risk of explosion producing lots of shrapnels.

I also remember that I have seen such pots on old machines - I will try to dig up a picture somewhere.....

It´s a nice part anyways, like it. :D

Eliteforum - 30-3-2004 at 03:16

How much did it cost? Seeming as though you got it off ebay 'n all.

If_6_was_9 - 30-3-2004 at 17:29

It didn't cost much, but I can't remember the exact price I paid for it. I think I was the only one to bid for it, from what I can remember. I've got some xerox copies from old catalogs which show metal retorts. I could scan them and post the pictures if anyone's interested.

[Edited on 31-3-2004 by If_6_was_9]

steam trap?

Magpie - 30-3-2004 at 19:34

I think Organikum may be on to something. This item does have the general shape and size of a steam trap, which is a necessary part of any machine that has condensate reuse.

If_6_was_9 - 31-3-2004 at 16:09

I wonder why it was under "old medical" on Ebay. I thought it might have something to do with sterilizing tools or something like that.

Eliteforum - 31-3-2004 at 16:27

The person selling it may not have known what it was/is used for.