I am a mechanical engineering student and have a desin project application question. In the picture, as you can see, the working tube, is a glass cylindrical tube, mounted onto main body of the furnace using a motor that rotates the tube at certain RPM. This is an open ended tube, and the blue holes on the end of the tube, show, where the seal, that i need to select should be mounted, onto the ends A,B of the tube, with ideally 2 holes in it for feeding of the material, that goes into the tube. Hence the seal needs to seal the ends, and be rotary so that the outer layer of the seal rotates with the tube, while the middle, which should have 2 ideal holes in it, stay stationary, so materilas that are to be added to the furnace tube can be fed through easily. for the process: Tungsten Oxide, Wo3+H2S-----> WS2 (Tungsten+H20) The two holes at end B, show one hole to let the gas product out in the gas chamber which sucks it away, and the other hole to collect the powdered material in a base, or likewise. These two holes will have pipes, or otherwise likewise material connected for feeding purposes. Any one know what such seals are called, and where they can be found or bought?? thanks , would be great help!