Housekeeper seals can be made with any kind of glass (usually soft glass) if the materials used fulfill the following requirements:
1. The expansion of the metal part must be larger than that of the glass in order to assure that the stresses normal to the glass-metal interface will always be compressive
2. The metal used must be soft enough and thin enough to be able to deform plastically, in order to allow dimensional changes which take place in the glass as it cools
3. The metal must form a strong bond with the glass
4. The shape and dimensions of the seal must be designed so, as to provide a large contact area between metal and glass, avoiding at the same time any tensile stress perpendicular to the surface or too great stresses in any direction
The metal fulfilling all the requirements is copper, but in some such seals platinum, iron (steal) and molybdenum can also be used. Using one or the other of these metals, the seal can be made in various shapes: wire seal, ribbon seal, feather-edge seal or dics seal.
For more info go to http://www.beltfurnaces.com
Like THT on facebook and get updates on all new blog posts, whitepapers, etc.
www.facebook.com/torreyhillstechnologies
No comments:
Post a Comment