Tapered furnace muffles

Patent metadata

Field	Value
Publication number	US-2019284084-A1
Application number	US-201916298605-A
Country	US
Kind code	A1
Filing date	Mar 11, 2019
Priority date	Mar 15, 2018
Publication date	Sep 19, 2019
Grant date	—

Abstract

An optical fiber draw furnace muffle includes a body portion defining a substantially cylindrical cavity extending along a centerline axis of the muffle. A tapered portion has an interior surface which defines a first curved portion with a first radius of curvature and a second curved portion with a second radius of curvature. At least one of the first and second radii of curvature has a radius greater than a radius of the cylindrical cavity.

First claim

What is claimed is:

1 . An optical fiber draw furnace muffle, comprising:
a body portion defining a substantially cylindrical cavity extending along a centerline axis of the muffle; and a tapered portion having an interior surface defining a first curved portion with a first radius of curvature and a second curved portion with a second radius of curvature, wherein at least one of the first and second radii of curvature has a radius greater than a radius of the cylindrical cavity.

2 . The furnace muffle of claim 1 , wherein one of the first and second radii of curvature is concave relative to the centerline axis.

3 . The furnace muffle of claim 2 , wherein one of the first and second radii of curvature is convex relative to the centerline axis.

4 . The furnace muffle of claim 1 , wherein the tapered portion defines an insert recess configured to receive a muffle insert.

5 . The furnace muffle of claim 4 , wherein the muffle insert defines an insert surface which is substantially flush with the interior surface.

6 . The furnace muffle of claim 5 , wherein the insert has an internal diameter of from about 4 cm to about 10 cm and an external diameter of from about 5 cm to about 10 cm.

7 . The furnace muffle of claim 4 , wherein at least one of the muffle insert and the muffle comprises graphite.

8 . The furnace muffle of claim 1 , wherein at least one of the first and second radii of curvature is from about 50 cm to about 100 cm.

9 . The furnace muffle of claim 1 , wherein at least one of the first and second radii of curvature is from about 10 cm to about 40 cm.

10 . An optical fiber draw furnace muffle, comprising:
a body portion defining a substantially cylindrical cavity extending along a centerline axis of the muffle; and a tapered portion having an interior surface defining a curved portion having a radius of curvature of from about 10 cm to about 100 cm, the tapered portion defining an insert recess configured to receive a muffle insert, wherein at least one of the muffle and the muffle insert comprise graphite.

11 . The furnace muffle of claim 10 , further comprising:
a gasket positioned between the muffle and the muffle insert.

12 . The furnace muffle of claim 10 , wherein the muffle insert has a length from about 5 cm to about 20 cm.

13 . The furnace muffle of claim 10 , wherein the muffle insert is in line with the centerline axis of the muffle.

14 . An optical fiber production system, comprising:
an optical fiber preform comprising glass; a heater; a muffle comprising: a body portion positioned around the preform, wherein the heater is positioned proximate the body portion and configured to heat the preform therein; and a tapered portion having an interior surface defining a first curved portion having a first radius of curvature and a second curved portion having a second radius of curvature, wherein at least one of the first and second radii of curvature is from about 10 cm to about 100 cm.

15 . The optical fiber production system of claim 14 , further comprising:
a muffle insert positioned within the muffle.

16 . The optical fiber production system of claim 15 , wherein the muffle insert is positioned proximate an outlet of the muffle.

17 . The optical fiber production system of claim 15 , wherein the muffle insert comprises graphite.

18 . The optical fiber production system of claim 14 , wherein one of the first and second radii of curvature is convex relative to a centerline axis of the muffle and one of the first and second radii of curvature is concave relative to the centerline axis of the muffle.

19 . The optical fiber production system of claim 14 , wherein the muffle comprises graphite.

20 . The optical fiber production system of claim 14 , wherein first and second curved portions are in contact.

Assignees

• Corning Inc

Inventors

• Anderson Erling Richard
• Jewell John Michael
• Nason Robert Walter
• Panides Elias
• Wang Xiaoyong
• Zheng Leo Young
• Zhou Chunfeng

Classifications

• C03B37/029 Primary

  Furnaces therefor · CPC title

• F27B5/14

  Arrangements of heating devices · CPC title

• C03B2205/92

  using means for gradually reducing the cross-section towards the outlet or around the preform draw end, e.g. tapered · CPC title

• C03B37/083

  Nozzles; Bushing nozzle plates (C03B37/095 takes precedence) · CPC title

• F27B5/10

  Muffles · CPC title