Air-tight sintering furnace for the production of a quartz preform
US5133796A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 28, 1990 |
| Grant date | Jul 28, 1992 |
| Priority date | — |
| Expiry date | Nov 28, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S65/90
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
This invention relates to a sintering furnace for the production of a quartz preform which can be used for carrying out dehydration, fluorine-addition and/or sintering of a porous quartz soot preform prepared by a flame hydrolysis method such as a VAD method or a OVD method, and in particular, to such a furnace in which joints in a long furnace muffle so long that fabricating it as open body is impossible can be maintained fully gas-tight, so that it is possible to prevent H.sub.2 O, O.sub.2 and other impurities in the air from entering the muffle from outside, and corrosive and poisonous gases in the muffle are prevented from leakage to outside the muffle. This sintering furnace has a muffle of high purity carbon, the inner wall and/or outer wall of which is coated with a gas-impermeable film, which muffle is a cylinder with an axis in the longitudinal direction and divided into a plurality of parts in the longitudinal direction, the parts each having the upper and lower ends finished so as to be flat and abutting adjacent parts sealed by a carbon gasket between them, and further has an air cylinder for pressing the parts together in the axial direction with a uniform force around…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.