Apparatus for and method of sealing shafts in crystal-growing furnace systems
US4406731A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 9, 1981 |
| Grant date | Sep 27, 1983 |
| Priority date | — |
| Expiry date | Jun 9, 2001 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T117/106
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
An apparatus for and a method of sealing a rotating shaft in a crystal-growing furnace, wherein the crystal-growing furnace includes a chamber adapted to be maintained at a contaminant-free inert atmosphere, with an inert gas at a low pressure, a rotatable shaft element which extends into the chamber, and a seal surrounding the shaft element, to separate the atmospheric pressure outside of the chamber from the low-pressure, contaminant-free atmosphere within the chamber, the seal having a plurality of sealing elements spaced apart along the shaft and defining an annular cavity between the sealing elements, the improvement which comprises means to and a method of maintaining an inert-gas atmosphere within the sealed cavity at a pressure slightly higher than the outside atmospheric pressure or the low pressure of the chamber, whereby, on failure of the sealing elements, inert gas passes from the cavity to the atmosphere or to the low-pressure chamber, thereby preventing the contamination of the chamber with atmospheric air.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.