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

Patent metadata

Field	Value
Publication number	US-11999646-B2
Application number	US-201917267496-A
Country	US
Kind code	B2
Filing date	Aug 2, 2019
Priority date	Aug 23, 2018
Publication date	Jun 4, 2024
Grant date	Jun 4, 2024

Abstract

In a method of manufacturing porous glass base for optical fiber, a liquid organic siloxane raw material stored in a raw material tank of internal pressure P1 is controlled by a mass flow controller at a predetermined flow rate and pumped through pipe of internal pressure P2 to a vaporizer, the liquid raw material is vaporized in the vaporizer and supplied as a gas raw material to a burner, and the silica fine particles formed by burning the gas raw material in the burner are deposited to form a porous glass base material, where P1≤P2 is satisfied.

First claim

The invention claimed is:

1. A manufacturing method of porous glass base material for optical fiber comprising:
pumping a liquid raw material of an organic siloxane stored in a raw material tank at internal pressure P 1 into a vaporizer through a pipe at internal pressure P 2 , controlled by a mass flow controller at a predetermined flow rate;
vaporizing the liquid raw material in the vaporizer and supplying the vaporized raw material to a burner as a gas raw material; and
forming a porous glass base material by depositing silica fine particles formed by burning the gas raw material in the burner,
wherein P 1 ≤P 2 is satisfied, and
wherein the manufacturing method further comprises a step of pumping the liquid raw material in the raw material tank to the mass flow controller using a liquid feed pump, wherein
a pressure of the liquid raw material supplied to the mass flow controller is P 3 , and
in the step of pumping the liquid raw material, the liquid feed pump once pressurizes the pressure of the liquid raw material to P 4 and supplies the liquid raw material to the mass flow controller while reducing the pressure to P 3 via a pressure loss unit, so that P 1 ≤P 2 <P 3 ≤0.6 P 4 is satisfied.

2. The manufacturing method as claimed in claim 1 , wherein part of the liquid raw material pressurized to P 4 by the liquid feed pump is returned to the raw material tank and the remainder is supplied to the mass flow controller.

3. The manufacturing method as claimed in claim 1 , wherein P 1 ≤0.1 MPa is satisfied.

4. The manufacturing method as claimed in claim 3 , wherein P 1 ≤0.05 MPa is satisfied.

5. The manufacturing method as claimed in claim 1 , wherein the pipe through which said liquid raw material flows is heated and kept at a temperature above the freezing point of the liquid raw material.

6. The manufacturing method as claimed in claim 1 , wherein the liquid raw material is octamethylcyclotetrasiloxane (OMCTS).

Assignees

• Shinetsu Chemical Co

Inventors

• Noda Naoto
• Inoue Dai
• Iinuma Hitoshi
• Mizukami Hiromasa

Classifications

• C03B37/01815 Primary

  Reactant deposition burners or deposition heating means · CPC title

• C03B2207/32

  Non-halide · CPC title

• C03B2207/34

  Liquid, e.g. mist or aerosol · CPC title

• C03B2207/81

  Constructional details of the feed line, e.g. heating, insulation, material, manifolds, filters · CPC title

• C03B2207/87

  Controlling the temperature · CPC title