JPH07277745A - Burner for formation of glass - Google Patents

Abstract

PURPOSE:To reduce labor required for newly determining and resetting the conditions in exchange by making it possible to exchange only a broken part when a nozzle is broken and, accordingly, reducing the influence by the individual difference in exchange. CONSTITUTION:A concentric-circle double tube nozzle 10 for introducing a raw material gas and six concentric-circle double tube nozzles 20 for generating oxygen-hydrogen flame are independently detachably attached to a frame 30 so that the nozzles 20 may surround the nozzle 10 existing at the central position. Silicon tetrachloride gas and argon gas are allowed to blow off through the central tube 11 of the nozzle 10 for introducing a raw material gas and argon gas is allowed to blow off through the outside tube 12. Oxygen gas is allowed to blow off through the respective central tubes 21 of six nozzles 20 for generating oxygen-hydrogen flame and hydrogen gas is allowed to blow off through the outside tubes 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a burner which produces glass particles by a gas phase reaction.

[0002]

2. Description of the Related Art In the VAD method or the like for producing a glass preform for optical fibers, glass (silicon dioxide) fine particles are produced by introducing a glass raw material gas such as silicon tetrachloride into an oxyhydrogen flame and performing a hydrolysis reaction. Produce and deposit this.
A burner is used to generate the flame and cause a hydrolysis reaction. Combustion gases of oxygen and hydrogen and a raw material gas carried as a carrier gas are fed into the burner. A conventional burner has a concentric multi-tube nozzle structure made of quartz glass or the like, and a raw material gas containing a carrier gas is ejected from a nozzle at the center of the burner.
From each of the outer multiple tubes, hydrogen gas and seal gas (argon, nitrogen,
Helium, etc.) and oxygen gas are blown out.

[0003]

However, in the conventional burner for producing glass having such a concentric multi-tube nozzle structure, it is necessary to newly set flame conditions at the time of replacement and reset the gas supply amount and the like. There's a problem. That is, if the burner continues to be used, the heat of the oxyhydrogen flame causes abrasion around the nozzle tip, which causes a change in flame temperature, making it impossible to perform stable glass particle deposition. In such a case, the conventional burner for glass production with the concentric multi-tube nozzle has no choice but to replace the entire burner, and the solid difference between the burners cannot be neglected. In order to perform the above, a new flame condition is newly obtained for the new burner, and the gas supply amount and the like are reset.

In view of the above, the present invention makes it possible to partially replace only a damaged nozzle, thereby making it difficult to be affected by the individual difference at the time of replacement, and resetting by newly finding a condition at the time of replacement. It is an object of the present invention to provide a burner for glass production, which can be improved so that the work to be performed can be reduced, and the flame temperature distribution can be controlled arbitrarily.

[0005]

In order to achieve the above object, in a burner for producing glass according to the present invention, a first nozzle for ejecting a glass raw material gas,
A second nozzle for generating a plurality of independent oxyhydrogen flames, which is arranged so as to surround the first nozzle;
And a holder for detachably holding the first and second nozzles at the above positions.

[0006]

The second nozzle is for generating an oxyhydrogen flame, and since a plurality of the second nozzles are arranged so as to surround the periphery of the first nozzle, the ring of the oxyhydrogen flame is formed. Then, the glass raw material gas ejected from the first nozzle is guided to the center of the flame. Therefore, a hydrolysis reaction occurs in this oxyhydrogen flame to generate glass particles. Since each of the first and second nozzles is independently and detachably held by the holding body, when any nozzle is damaged, only the damaged nozzle can be replaced. In addition, a first nozzle for ejecting the glass raw material gas and a second nozzle for generating a plurality of independent oxyhydrogen flames are provided, and since these are independent, a plurality of oxyhydrogen flame generating nozzles are provided. The flame temperature distribution can be arbitrarily controlled by adjusting the flow rates of the oxygen gas and the hydrogen gas separately for each.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the drawings. As shown in FIG. 1, the glass forming burner according to the present invention is configured as an assembly of a plurality of nozzles. The nozzle 10 located at the center is for introducing the raw material gas, and the six nozzles 20 arranged so as to surround the periphery thereof are for generating the oxyhydrogen flame. Each of these seven nozzles has a concentric double tube structure. A silicon tetrachloride gas and an argon gas are ejected from the central pipe 11 of the raw material gas introduction nozzle 10, and an argon gas is ejected from a peripheral pipe 12 thereof. Oxygen gas from the central tube 21 of the oxyhydrogen flame generation nozzle 20,
Hydrogen gas is blown out from the peripheral pipe 22.

The tubes 11, 12, 21, of these nozzles,
22 is formed of a quartz glass pipe. For example, the central tube 11 of the nozzle 10 has an inner diameter of 2.0 m.
m, outer diameter 3.6 mm, peripheral tube 12 has inner diameter 5.0 mm, outer diameter 6.6 mm, central tube 21 of nozzle 20 has inner diameter 2.0 m
m, outer diameter 3.6 mm, the peripheral tube 22 has an inner diameter 10.0 mm,
The outer diameter is 12.0 mm. The nozzles 10 and 20 are held by an appropriate frame 30 and are individually replaceable. That is, here, the nozzles 10 and 20 are detachably fitted and held in the frame 30.

Six oxyhydrogen flame generating nozzles 20 are used here, and these are the main source gas introducing nozzles 1.
Since it is arranged so as to form a ring around 0, a ring-shaped oxyhydrogen flame is formed as in the conventional concentric multi-tube structure nozzle. Then, toward the center of the oxyhydrogen flame, since the raw material gas of the glass is ejected from the raw material gas introduction nozzle arranged in the center, the glass raw material gas will be introduced into the center of the oxyhydrogen flame,
As in the conventional case, the generation of glass fine particles by the hydrolysis reaction is performed with good efficiency.

When this glass-forming burner is used for a long period of time, the heat of the oxyhydrogen flame generated at the tip of the burner melts the tip and gradually scrapes it. When such damage such as scraping occurs, only the damaged nozzle is removed from the frame 30, replaced with a new nozzle, and the new nozzle is mounted on the frame 30. As a result, it is possible to avoid replacing the entire burner and replace only a part thereof, so that the difference in gas ejection characteristics before and after replacement is reduced. In this way, the influence of the solid difference can be suppressed to a small degree, so that it is possible to reduce the need to newly determine the flow rate conditions of each gas after replacement and the need to reset the flow rate conditions of each gas accordingly. Is possible.

Further, since a plurality of independent oxyhydrogen flame generating nozzles 20 are arranged around the raw material gas introducing nozzle 10, oxygen gas and hydrogen gas are provided for each of the plurality of oxyhydrogen flame generating nozzles 20. It is possible to adjust the flow rate of each separately, which opens a way to arbitrarily control the flame temperature distribution, which was impossible in the past, and to control the deposition rate and efficiency of glass particles, the refractive index distribution, etc. Can be improved.

[0012]

As described above, according to the burner for producing glass of the present invention, when a trouble occurs in a part of the nozzle such as when the tip of the nozzle is damaged, the burner is not replaced as a whole. This can be dealt with by replacing only some of the nozzles. Therefore, the difference in the gas ejection characteristics before and after the replacement is reduced, and the work of newly determining the flow rate condition of each gas after the replacement and resetting the flow rate condition of each gas accordingly can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a glass forming burner according to an embodiment of the present invention.

[Explanation of symbols]

 10 Nozzle for introducing raw material gas 11 Central pipe for nozzle for introducing raw material gas 12 Peripheral pipe for nozzle for introducing raw material gas 20 Nozzle for generating oxyhydrogen flame 21 Central pipe for nozzle for generating oxyhydrogen flame 22 Surrounding nozzle for generating oxyhydrogen flame Tube 30 frame

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location // G02B 6/00 356 A

Claims (1)

[Claims] 1. A first nozzle for ejecting a glass source gas, and a second nozzle for surrounding a plurality of independent oxyhydrogen flames, which is arranged so as to surround the first nozzle. And a holder for detachably holding the first and second nozzles at the above-mentioned positions.