Heating apparatus and method for manufacturing optical fiber base material

Patent metadata

Field	Value
Publication number	US-2022073405-A1
Application number	US-202117455802-A
Country	US
Kind code	A1
Filing date	Nov 19, 2021
Priority date	Jun 6, 2019
Publication date	Mar 10, 2022
Grant date	—

Abstract

A heating apparatus includes: a furnace core tube configured to house a glass base material; a heating device installed at outer periphery of the furnace core tube; and a controller configured to control the heating device. The heating device includes a plurality of independently-controllable heaters arranged along a longitudinal direction of the glass base material. The heaters are grouped into a plurality of heating groups controllable in an independent manner by the controller. Each of the heating groups includes at least one of the heaters configured to heat the furnace core tube.

First claim

What is claimed is:

1 . A heating apparatus comprising:
a furnace core tube configured to house a glass base material; a heating device installed at outer periphery of the furnace core tube; and a controller configured to control the heating device, wherein the heating device includes a plurality of independently-controllable heaters arranged along a longitudinal direction of the glass base material, the heaters are grouped into a plurality of heating groups controllable in an independent manner by the controller, and each of the heating groups includes at least one heating unit configured to heat the furnace core tube.

2 . The heating apparatus according to claim 1 , wherein
each of the heating groups includes a power source configured to supply electrical power to that heating group, and the controller is configured to independently control the power source included in each of the heating groups.

3 . The heating apparatus according to claim 2 , further comprising temperature measuring circuitry configured to measure temperature of the furnace core tube, wherein
based on measured value as obtained by the temperature measuring circuitry, the controller is configured to adjust electrical power supplied to each of the heating groups.

4 . The heating apparatus according to claim 1 , wherein the heating group includes a plurality of the heating units.

5 . The heating apparatus according to claim 1 , wherein the heater includes at least six of the heating units.

6 . The heating apparatus according to claim 1 , wherein the at least one heating unit is configured using molybdenum disilicide.

7 . The heating apparatus according to claim 1 , wherein heater diameter of the at least one heating unit is equal to or greater than 10 mm.

8 . A method for manufacturing an optical fiber base material, the method being executed by using a heating apparatus including: a furnace core tube configured to house a porous optical fiber base material made of a core and a porous glass formed at outer periphery of the core, a heating device installed at outer periphery of the furnace core tube, and a controller configured to control the heating device, wherein the heating device includes a plurality of independently-controllable heaters arranged along a longitudinal direction of the porous optical fiber base material, the heaters are grouped into a plurality of heating groups controllable in an independent manner by the controller, and each of the heating groups includes at least one heating unit configured to heat the furnace core tube, the method comprising:
inserting the porous optical fiber base material in the furnace core tube of the heating apparatus; and performing thermal dehydration in an atmosphere that includes at least a dehydration gas.

Assignees

• Furukawa Electric Co Ltd

Inventors

• Suzuki Tsuneo
• Miyake Hiroshi

Classifications

• H10P72/0431

  Apparatus for thermal treatment · CPC title

• C03B37/0146 Primary

  Furnaces therefor, e.g. muffle tubes, furnace linings · CPC title

• C03B37/07

  Controlling or regulating ({C03B37/0253 takes precedence } ; controlling or regulating in general G05) · CPC title

• F27B1/26

  Arrangements of controlling devices · CPC title

• F27B1/28

  Arrangements of monitoring devices, of indicators, of alarm devices · CPC title