On-line annealing of large fused quartz ingots
OwnerAlan MUNDY, Ian George SAYCE +1inventors
InventorsAlan MUNDY, Ian George SAYCE, Boris GROMANN
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Abstract
A method and apparatus for manufacturing a quartz glass ingot of large cross-sectional area by continuous flame-fusion whereby on-line crack-free cutting of the ingot is ensured by using the internal heat of the ingot to permit equilibration of the internal and surface temperatures while passing through one or more annealing chambers, thus ensuring controlled cooling to temperature at which it is possible to cut the ingot with a water-cooled saw.
Claims14
A method for continuous production of quartz-glass ingots, of cross-sectional area greater than 96000 mm2, comprising the following process steps:
- a. providing a softened quartz-glass material in a crucible or refractory tank;
- b. vertically drawing off the softened quartz-glass mass through a die to provide a quartz-glass ingot;
- and
- c. on-line cutting of the quartz-glass ingot to a specific length,
- characterized in that, prior to step c., the quartz-glass ingot is passed through at least one insulated chamber in which controlled cooling of the ingot is caused to take place.
An apparatus for the continuous production of quartz-glass ingots, comprising the following means:
- (a) a crucible or refractory tank for providing a softened quartz-glass mass having a die orifice in the bottom of the crucible or refractory tank;
- (b) means for vertically drawing off the softened quartz-glass mass through a die to provide a quartz-glass ingot;
- and
- (c) means for on-line cutting of the hollow quartz-glass ingot to a specific length,
- characterized in that the apparatus comprises means for an on-line annealing of the quartz-glass ingot prior to step c.
The apparatus according to claim 10, characterized in that the means for the on-line annealing are adjustable plates.
Dependencies are inferred from the claim text.