Manufacturing apparatus and manufacturing method of porous glass base material for optical fiber

Patent metadata

Field	Value
Publication number	US-11427495-B2
Application number	US-202016896623-A
Country	US
Kind code	B2
Filing date	Jun 9, 2020
Priority date	Jun 11, 2019
Publication date	Aug 30, 2022
Grant date	Aug 30, 2022

Abstract

A manufacturing apparatus of a porous glass base material for optical fiber includes: a liquid mass flow controller for controlling a flow rate of a raw material liquid of an organic siloxane; a vaporizer for mixing the raw material liquid and a carrier gas to vaporize the raw material liquid to form a mixed gas in which a raw material gas and the carrier gas are mixed; a raw material liquid nozzle for ejecting the raw material liquid into the vaporizer; a carrier gas supply pipe for supplying the carrier gas into the vaporizer; a raw material liquid pipe for introducing the raw material liquid into the raw material liquid nozzle; a burner for combusting the mixed gas together with a combustible gas and a combustion supporting gas to produce SiO2 fine particles; a mixed gas pipe; an open/close valve; and a purge gas supply pipe.

First claim

What is claimed is:

1. A manufacturing method of a porous glass base material for optical fiber comprising:
controlling a flow rate of a raw material liquid of an organic siloxane by a liquid mass flow controller;
introducing the raw material liquid supplied from the liquid mass flow controller to a raw material liquid nozzle of a vaporizer by a raw material liquid pipe;
ejecting the raw material liquid from the raw material liquid nozzle into the vaporizer;
mixing the raw material liquid ejected in the vaporizer and a carrier gas to vaporize the raw material liquid to form a mixed gas in which the raw material gas and the carrier gas are mixed;
supplying the mixed gas to a burner;
combusting the mixed gas together with a combustible gas and a combustion supporting gas in the burner to produce SiO 2 particles;
depositing SiO 2 particles on a starting core base material to form the porous glass base material for optical fiber;
closing an open/close valve provided on a flow path of the raw material liquid pipe to stop the supply of the raw material liquid from the liquid mass flow controller; and
supplying a purge gas from a purge gas supply pipe that joins the raw material liquid pipe between the open/close valve and the raw material liquid nozzle to the raw material liquid pipe.

2. The manufacturing method according to claim 1 further comprises additionally mixing oxygen gas into the mixed gas and supplying the mixed gas to the burner.

3. The manufacturing method according to claim 2 , wherein when a flow rate of the purge gas supplied from the purge gas supply pipe is L P and a flow rate of the oxygen gas additionally mixed is L O2 in the supplying the purge gas to the raw material liquid pipe, the purge gas and the oxygen gas are respectively supplied so that L O2 /L P >14 is satisfied.

4. The manufacturing method according to claim 1 , wherein when a flow rate of the purge gas supplied from the purge gas supply pipe is L P and a flow rate of the carrier gas supplied to the vaporizer is L C , in the supplying the purge gas to the raw material liquid pipe, the purge gas and the carrier gas are respectively supplied so that L C /L P >10 is satisfied.

5. The manufacturing method according to claim 1 , wherein the carrier gas is any of nitrogen, argon, and helium.

6. The manufacturing method according to claim 1 , wherein the organic siloxane is octamethylcyclotetrasiloxane (OMCTS).

Assignees

• Shinetsu Chemical Co

Inventors

• Noda Naoto
• Iinuma Hitoshi

Classifications

• G02B1/046

  characterised by the core material · CPC title

• C03B37/0142

  Reactant deposition burners · CPC title

• C03B37/01433 Primary

  for delivering and depositing additional reactants as liquids or solutions, e.g. for solution doping of the porous glass preform · CPC title

• C03B37/016

  by a liquid phase reaction process, e.g. through a gel phase · CPC title

• G02B1/045

  Light guides · CPC title