JPS604978Y2 - Glass particle synthesis torch - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a glass particle synthesis torch.

A glass fine particle synthesis torch (hereinafter referred to as a synthetic leather torch) with a vapor phase shaft is used when manufacturing optical fiber base material according to the method.
A schematic diagram of a typical example of an apparatus for manufacturing an optical fiber preform is shown in FIG.

In the figure, 1 is a synthetic leather torch, 2 is a starting material, 3 is a porous glass base material, 4 is a rotating pulling device, 5 is an electric furnace, 6 is a heating element,
7 is a base material for optical fiber.

In order to manufacture an optical fiber base material using such a device, first, glass fine particles are synthesized with a synthetic leather torch 1, and the synthesized glass particles are attached to the end face of a starting material 2 with this synthetic leather torch 1. , deposited to form a rod-shaped porous glass body 3
to form.

The porous glass body 3 is rotated and pulled up by a rotary pulling device 4, and introduced into an electric furnace 5.

Here, the porous glass body 3 is heated to 150,000 to 1,600°C by a heating element 6 in an electric furnace 5, and a transparent optical fiber base material 7 is continuously obtained.

The temperature distribution on the deposition surface of the porous glass body 3 produced using such a conventional synthesis torch is high in the center and low along the radial direction.

Therefore, the density of the porous glass body 3 is also high in the central part.
It was lower along the radial direction.

In this way, the non-uniform density of the porous glass body 3 in the radial direction causes cracks to occur in the porous glass body 3. It is difficult to make it into transparent vitrification, and even if it could be made into transparent vitrification, it could not be used as the optical fiber base material 7.

On the other hand, with the recent demand for optical fibers, the economic efficiency of optical fibers has been brought into question.

Therefore, high-speed production is desired in the production of optical fiber preforms.

In order to manufacture optical fiber base material at high speed using the above-mentioned vapor phase shafting method, it is sufficient to increase the deposition rate of the porous glass body 3, but as the deposition rate increases, the The diameter also increases, and as a result, the density in the radial direction becomes increasingly non-uniform, making it difficult to stably produce a porous glass preform.

The object of the present invention is to provide a glass particle synthesis torch that does not have such drawbacks.

Specifically, the purpose is to provide a synthetic leather torch that achieves uniform temperature distribution in a porous glass body, prevents cracking, and is capable of stably and rapidly synthesizing large diameter porous glass bodies. .

Therefore, the glass particle synthesis torch according to the present invention is
It is characterized by having one or more outlets for injecting glass forming raw materials, combustible gas, and combustion assisting gas, and an auxiliary combustible gas outlet and an auxiliary combustion assisting gas outlet provided outside the outlet. It is something to do.

A typical embodiment of the present invention will be described based on the drawings.

FIG. 2 is a sectional view of an embodiment of the glass particle synthesis torch according to the present invention, in which 20 is the synthetic leather torch body, 21
22 is an inert gas (for example,
23 is a combustible gas outlet, 24 is an auxiliary gas outlet, 25 is an auxiliary combustible gas outlet, and 26 is an auxiliary auxiliary gas outlet.

As is clear from this FIG.
1. An inert gas outlet 22, a combustible gas outlet 23, and a combustible gas outlet 24 are sequentially provided on the outside thereof,
An auxiliary combustible gas outlet 25 and an auxiliary combustion auxiliary gas outlet 26 are provided outside the combustible gas outlet 24, that is, in the outermost layer of the synthetic leather torch body 20 in this embodiment.

To explain the action of this synthetic leather torch, combustible gas (for example, N2) and combustion assisting gas (for example, 02) are injected from the flammable gas outlet 23 and the combustion assisting gas outlet 24.
Accordingly, the glass-forming raw material (for example, 5iC1°GeCl4POCl3, etc.) flowing out from the glass-forming raw material outlet 21 is flame-hydrolyzed and glass fine particles are synthesized.

Auxiliary flammable gas outlet 2 on the outermost side of the synthetic leather torch body 20
The combustible gas and the combustion auxiliary gas flowing out from 5 and the auxiliary combustion auxiliary gas outlet 26 have no relation to the synthesis of glass particles, and only serve to uniformize the temperature distribution on the deposition surface of the porous glass body. fulfill.

Therefore, a porous glass body having a uniform density distribution in the radial direction is synthesized, and as a result, the problem of cracking can be solved, and high-speed production of porous glass base materials becomes possible.

Example Using the synthetic leather torch shown in FIG. When a porous glass body of φ is manufactured, the surface temperature of the porous glass body is 700℃ near the center and 3.5℃ from the center.
The temperature was 680° C. at a distance of m, and a porous glass body with a length of 70 cm could be stably produced without any problem of cracking.

Further, when the density distribution of this porous glass body was investigated, it was confirmed that it was almost uniform in the radial direction.

For comparison, an attempt was made to manufacture a porous glass body with a diameter of 80 mm without flowing flammable gas and combustion auxiliary gas from the auxiliary combustible gas outlet 25 and the auxiliary combustion auxiliary gas outlet 26. The temperature was 700° C. near the center and 400° C. at a location 3.5 cm away from the center, and when the porous glass body was manufactured to a length of about 5 cm, cracks occurred and manufacturing became impossible thereafter.

As explained above, by providing the auxiliary combustible gas outlet and the auxiliary combustion auxiliary gas outlet on the outermost layer of the synthetic leather torch with a circular cross section, porous glass with a uniform temperature distribution on the deposition surface is created. The body can be manufactured stably.

Therefore, the density in the radial direction of the produced porous glass body also becomes more uniform.

As a result, it is possible to solve the problem of cracking that occurs when producing a porous glass base material having a large diameter, and there is an advantage that it is easy to increase the size of the porous glass body.

Further, as the size of the porous glass body increases, the amount of production per unit time increases, which has the advantage of contributing to lower costs of optical fibers.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an optical fiber preform manufacturing apparatus, and FIG. 2 is a sectional view of an embodiment of a glass fine particle synthesis torch according to the present invention. 1...Synthetic leather torch, 2...Starting material, 3
... Porous glass body, 4 ... Rotary pulling device, 5 ... Electric furnace, 6 ... Heating element, 7 ... Light Base material for fiber, 20...
Synthesis torch main body, 21...Glass forming raw material outlet, 22...Inert gas outlet, 23...
...Flammable gas outlet, 24... Combustion auxiliary gas outlet, 25... Auxiliary combustible gas outlet, 26.
...Auxiliary combustion auxiliary gas outlet.

Claims (1)

[Scope of utility model registration request] It is characterized by having one or more outlets through which glass forming raw materials, combustible gas, and combustion assisting gas flow out, and an auxiliary combustible gas outlet and an auxiliary combustion assisting gas outlet provided outside the outlet. Glass particle synthesis torch.