Sealing a chemical Reaction in furnace(Final Beng mechanical Eng. project)

[maqadir]

HELP NEEDED Sealing chemical Reaction in furnace(Beng mech Eng. project)

Hello everyone,
I had posted a similar thread earlier, got a few responses, but nothing enough to drive me out of my problem, even my project supervisor at Uni of Notts is confused!
(https://www.physicsforums.com/showthread.php?t=283985)

I just thought, as a last ditch effort, maybe someone could help me this time around.
The picture below, shows the furnace that i have to work with ( the mechanical bits of this project are that i have to design a motor, that makes the tube rotate, as shown by the bold arrows because currently that tube just sits stationary

http://s3.supload.com/free/Furnace.jpg/view/

Now, since its an open ended tube, and hollow, the material fed in, is a solid state powder ( tungsten oxide) and gas ( hydrogen sulphide) which is toxic and smelly!

Now as a mechanical engineer, i have already designed a motor and a way that will make the tube rotate, however, for the life in me, i cannot find out how to seal the two ends ( sealing the two ends is very important as the gas being fed is toxic)

Also the seal needs to be such that, only the outer bit of the seal rotates with the tube, and the middle remains stationary, so that material can be fed through the middle. Note: Material can't be fed through, if the tube is sealed with a method, whereby both the tube and seal rotate. Also the seal should have holes for feeding

Any ideas?

Thankyou

 

[minger]

Have you considered something along the lines of a magnetic seal? Where is the seal located, and what temperatures conditions will it be under?

 

[maqadir]

Have you considered something along the lines of a magnetic seal? Where is the seal located, and what temperatures conditions will it be under?

The seal once i have found the right one, will go onto the ends of the working tube. ( the thing is, the tube rotates in the furnace already. Since its rotating, and its open ended, it needs to be sealed, because gas is going to be fed in. No you can seal it with almost anything that can stand temperatures of up to 200 Degrees C, but obviously, if i use anything to seal it, the seal too will rotate, making it impossible to feed the gas. So i need a seal, that can stand temperatures of up to 200 degrees C, and not rotate along with the tube and also have two holes, so that the gas and powder can be fed into the working tube easily.
ID of the glass tube is 34:38 (inneruter diameter in mm)

 

[Topher925]

Your best bet it to look at pneumatic couplers, like the ones used for air hoses on compressed air systems.