JPH0971430A - Production of preformed material for optical fiber and production unit therefor - Google Patents

Production of preformed material for optical fiber and production unit therefor

Info

Publication number
JPH0971430A
JPH0971430A JP22908595A JP22908595A JPH0971430A JP H0971430 A JPH0971430 A JP H0971430A JP 22908595 A JP22908595 A JP 22908595A JP 22908595 A JP22908595 A JP 22908595A JP H0971430 A JPH0971430 A JP H0971430A
Authority
JP
Japan
Prior art keywords
glass
gas
optical fiber
producing
burner
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP22908595A
Other languages
Japanese (ja)
Inventor
Motonori Nakamura
元宣 中村
Yuichi Oga
裕一 大賀
Toshio Danzuka
俊雄 弾塚
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sumitomo Electric Industries Ltd
Original Assignee
Sumitomo Electric Industries Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sumitomo Electric Industries Ltd filed Critical Sumitomo Electric Industries Ltd
Priority to JP22908595A priority Critical patent/JPH0971430A/en
Publication of JPH0971430A publication Critical patent/JPH0971430A/en
Pending legal-status Critical Current

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03BMANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B37/00Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
    • C03B37/01Manufacture of glass fibres or filaments
    • C03B37/012Manufacture of preforms for drawing fibres or filaments
    • C03B37/014Manufacture of preforms for drawing fibres or filaments made entirely or partially by chemical means, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD]
    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03BMANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B37/00Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
    • C03B37/01Manufacture of glass fibres or filaments
    • C03B37/012Manufacture of preforms for drawing fibres or filaments
    • C03B37/014Manufacture of preforms for drawing fibres or filaments made entirely or partially by chemical means, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD]
    • C03B37/0144Means for after-treatment or catching of worked reactant gases

Abstract

PROBLEM TO BE SOLVED: To obtain a preformed material improved in yield by introducing clean air into a vessel and conducting a control so that the difference between the maximum and the minimum values of the surface temperature of a glass fine particle body come to a specified level at a specific position of the body. SOLUTION: First, a stock gas such as SiCl4 , fuel gas such as H2 or O2 , inert gas such as N2 are fed to a gas feeder 6 and injected through a multiply tubular burner 5 into a reaction vessel 8 to form a glass fine particle deposit 2. Secondly, the temperature distribution around the deposit 2 is determined by a thermometer 7 and, in response to a command from a CPU 9 into which temperature distribution data have been inputted in advance, the clean excess air flow via a suction port 3a through a filter and the gas inflow from the gas feeder 6 are controlled. Subsequently, the difference between the maximum and minimum values of the surface temperature of the deposit 2 is controlled so as to come to >=60 deg.C below a position where the surface temperature of the deposit 2 presents the maximum value and within the range with a diameter being 50% of that of the deposit 2, thus obtaining the objective bubble-free preformed material for optical fibers in high yield.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は、光ファイバ用母材を収
率よく製造することのできる方法及びその装置に関す
る。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for producing an optical fiber preform with a high yield.

【0002】[0002]

【従来の技術】従来、出発ロッドの上に円筒状のバーナ
によって生成されたガラス微粒子を効率よく堆積する方
法として、バーナの軸を出発ロッドの軸に対して一定の
範囲傾けて堆積する方法がある(特開昭61−1862
40号公報)。
2. Description of the Related Art Conventionally, as a method for efficiently depositing fine glass particles produced by a cylindrical burner on a starting rod, there is a method of depositing the axis of the burner with a certain range of inclination with respect to the axis of the starting rod. There is (JP-A-61-1862)
No. 40).

【0003】[0003]

【発明が解決しようとする課題】上記の方法によって生
成されたガラス微粒子が次々と堆積するのは、ガラス微
粒子が高温側から低温側へと向かっていく力を受けると
いうサーモホレシス効果によるものである。ところで前
述の方法では、堆積中のガラス微粒子はサーモホレシス
効果を積極的には利用していないために、ガラス微粒子
の堆積速度を上げるのに限界があった。即ち、投入する
ガラス原料を増加していっても、ある程度堆積速度ある
いは成長速度の向上がみられるものの、原料投入量に対
して実際に堆積する量の割合が減少し、収率は上がらな
かった。 また、このガラス微粒子体を高温に加熱して
透明化したときに、ガラス中に気泡が発生する場合があ
り、線引き工程において断線の原因もなった。そこで本
発明は、かかる問題点を解決し、高収率で気泡の生じな
い光ファイバ用母材の製造方法及びその装置を提供する
ことを目的とする。
The fact that the glass fine particles produced by the above method are successively deposited is due to the thermophoresis effect in which the glass fine particles receive a force from the high temperature side toward the low temperature side. By the way, in the above-mentioned method, since the glass particles during deposition do not positively utilize the thermophoresis effect, there is a limit in increasing the deposition rate of the glass particles. That is, although the deposition rate or the growth rate was improved to some extent even if the glass raw material to be added was increased, the ratio of the amount actually deposited to the input amount of the raw material was decreased and the yield was not increased. . Further, when the glass fine particles are heated to a high temperature to be transparent, air bubbles may be generated in the glass, which also causes a disconnection in the drawing process. Therefore, it is an object of the present invention to solve the above problems and to provide a method and an apparatus for manufacturing an optical fiber preform that does not cause bubbles in a high yield.

【0004】[0004]

【課題を解決するための手段】本発明に係わる光ファイ
バ用母材の製造方法は、容器内に垂直方向に移動可能に
把持され、軸回りに回転する出発ロッドの上部から下部
に向かってガラス微粒子体を積層する光ファイバ用母材
の製造方法であって、 容器内に導入する余剰空気につ
いては市販のクリーンエアジェネレータなどを用いて空
気中に含まれる塵埃を除去し、清浄な空気とした後導入
し、ガラス微粒子体の表面温度の最高値を示す位置より
下方で、かつ、ガラス微粒子体の直径の50%の径を有
する範囲において、ガラス微粒子体の表面温度の最高値
と最低値の差が60℃以上であるように制御することを
特徴とし、 また、表面温度が極大値を有する場合は最
高値と極小値の差が60℃以上であるように制御するこ
とを特徴とする。
A method of manufacturing a base material for an optical fiber according to the present invention comprises a starting rod which is held in a container so as to be vertically movable and rotates around an axis from a top to a bottom of a glass rod. A method for manufacturing a preform for optical fibers in which fine particles are laminated, and excess air to be introduced into the container is cleaned with a commercially available clean air generator to remove dust contained in the air. Introduced later, below the position showing the maximum value of the surface temperature of the glass particulate body, and in the range having a diameter of 50% of the diameter of the glass particulate body, the maximum and minimum values of the surface temperature of the glass particulate body The difference is controlled to be 60 ° C. or more, and when the surface temperature has a maximum value, the difference between the maximum value and the minimum value is controlled to be 60 ° C. or more.

【0005】具体的には、容器内に余剰空気を導入して
ガラス微粒子体の下部に吹き付け、該余剰空気の流量を
調整することを特徴とし、余剰空気はフィルタを通過さ
せて清浄な空気とする方法が好ましい。
Specifically, the excess air is introduced into the container and blown onto the lower part of the glass fine particles to adjust the flow rate of the excess air, and the excess air is passed through a filter to obtain clean air. Is preferred.

【0006】上記光ファイバ用母材の製造方法において
温度差を制御する手段としては、ガラス微粒子を生成す
るバーナは多重管構造をなし、少なくとも1つのガス流
出ポートを偏心して形成し、偏心したポートからは燃料
ガスが流出することを特徴とする。
As means for controlling the temperature difference in the above-mentioned method for producing a preform for optical fibers, a burner for producing fine glass particles has a multi-tube structure, and at least one gas outflow port is formed eccentrically, and the eccentric port is formed. It is characterized in that fuel gas flows out from the.

【0007】上記光ファイバ用母材の製造方法において
温度差を制御する他の手段としては、ガラス微粒子を生
成するバーナは多重管構造をなし、少なくとも1つの管
に接続されるガス導入口が複数個設けられ、該複数のガ
ス導入口から夫々燃料ガスを供給することを特徴とす
る。
As another means for controlling the temperature difference in the above-mentioned method for producing a base material for an optical fiber, the burner for producing fine glass particles has a multi-tube structure, and a plurality of gas inlets connected to at least one tube are provided. It is characterized in that the fuel gas is individually provided and the fuel gas is supplied from each of the plurality of gas introduction ports.

【0008】上記光ファイバ用母材の製造方法において
温度差を制御する他の手段としては、ガラス微粒子を生
成するバーナは多重管構造をなし、各ポートからは独立
にガス量を制御して流出させることができ、外周部のポ
ートに供給する燃料ガスを90〜100%の範囲で制御
することを特徴とする。
As another means for controlling the temperature difference in the above-mentioned method for producing a preform for optical fibers, the burner for producing glass particles has a multi-tube structure, and the amount of gas is independently controlled to flow out from each port. The fuel gas supplied to the ports on the outer peripheral portion is controlled in the range of 90 to 100%.

【0009】本発明に係わる光ファイバ用母材の製造装
置は、反応容器と、反応容器の上部を貫通して上下方向
及び軸回りに移動又は回転可能に設けられた出発ロッド
と、ガラス微粒子を生成するバーナと、外部から空気を
取り入れる吸入口と、バーナと対向する位置に設けられ
た排気口とを備え、出発ロッドの上部から下部に向かっ
てガラス微粒子を積層する光ファイバ用母材の製造装置
であって、外部空気の取込み口には空気中の浮遊異物を
除去するフィルタを備え、ガラス微粒子体の表面温度の
最高値を示す位置より下方で、かつ、ガラス微粒子体の
直径の50%の径を有する範囲において、ガラス微粒子
体の表面温度の最高値と最低値の差が60℃以上である
ように調整するための温度制御装置及びガラス微粒子体
の外径を測定するための外径測定装置を有することを特
徴とする。
The optical fiber preform producing apparatus according to the present invention comprises a reaction container, a starting rod penetrating the upper part of the reaction container and movable or rotatable in the vertical direction and around the axis, and glass fine particles. Manufacture of a preform for optical fibers in which a burner for generation, an intake port for taking in air from the outside, and an exhaust port provided at a position facing the burner are provided, and glass fine particles are laminated from the upper part of the starting rod toward the lower part The device is provided with a filter for removing suspended foreign matters in the air at an intake port of external air, which is below a position where the maximum surface temperature of the glass fine particles is shown, and is 50% of the diameter of the glass fine particles. In the range having the diameter of, the temperature control device for adjusting the difference between the maximum value and the minimum value of the surface temperature of the glass fine particles is 60 ° C. or more, and the outer diameter of the glass fine particles is measured. And having an outer diameter measuring device fit.

【0010】[0010]

【作用】上記の構成によれば、本発明に係わる光ファイ
バ用母材の製造方法は、ガラス微粒子の堆積中にその表
面温度の最高値と最低値の差が60℃以上であるように
制御するので、その結果、サーモホレシス効果が向上し
てガラス微粒子の堆積効率を上げることができる。 ま
た、反応容器内に取り込む余剰空気内に含まれる異物を
除去することにより、雰囲気中の異物に起因する気泡発
生要因を低減できるので、気泡の発生頻度を低減するこ
とができる。さらに、本発明の製造装置、特にガラス微
粒子の表面温度が最小となる近傍に余剰空気を導入する
ための吸入口が設けられ、又多重管バーナは温度差を生
じる構成となっているために、サーモホレシス効果を増
大させ、高収率の効果的手段となっている。
According to the above construction, in the method for producing an optical fiber preform according to the present invention, the difference between the maximum value and the minimum value of the surface temperature of glass fine particles is controlled to be 60 ° C. or more during the deposition. As a result, the thermophoresis effect is improved, and the deposition efficiency of the glass particles can be increased. Further, by removing the foreign matter contained in the surplus air taken into the reaction container, it is possible to reduce the factor of bubble generation due to the foreign matter in the atmosphere, so that the frequency of bubble generation can be reduced. Further, since the manufacturing apparatus of the present invention, in particular, the suction port for introducing the excess air is provided in the vicinity where the surface temperature of the glass particles is minimized, and the multi-tube burner is configured to cause a temperature difference, It increases the thermophoresis effect and is an effective means of high yield.

【0011】[0011]

【実施例】以下、添付図面を参照して本発明の実施例を
説明する。なお、図面の説明において同一要素には同一
符号を付し、重複する説明を省略する。図1は本実施例
に係わる光ファイバ用母材の製造装置の構成を示す概略
図である。本装置は反応容器8と、反応容器の上部を貫
通して上下方向及び軸回りに移動又は回転可能に設けら
れた出発ロッド1と、ガラス微粒子を生成するバーナ5
と、外部から空気を取り入れる吸入口3と、バーナと対
向する位置に設けられた排気口4とを備え、ガス供給装
置6からは四塩化珪素等のガラス原料ガス、水素ガス、
酸素ガス等の燃料ガスとアルゴンガス等の不活性ガスを
ガラス微粒子堆積用バーナ5に供給し、火炎加水分解反
応させて出発ロッド1の周囲にガラス微粒子堆積体2を
形成する。
Embodiments of the present invention will be described below with reference to the accompanying drawings. In the description of the drawings, the same elements will be denoted by the same reference symbols, without redundant description. FIG. 1 is a schematic diagram showing the configuration of an optical fiber preform manufacturing apparatus according to this embodiment. This apparatus comprises a reaction container 8, a starting rod 1 penetrating the upper part of the reaction container so as to be movable or rotatable in the vertical direction and around an axis, and a burner 5 for producing glass particles.
And a suction port 3 for taking in air from the outside, and an exhaust port 4 provided at a position facing the burner. From the gas supply device 6, a glass raw material gas such as silicon tetrachloride, hydrogen gas,
A fuel gas such as oxygen gas and an inert gas such as argon gas are supplied to the burner 5 for depositing glass particles, and a flame hydrolysis reaction is performed to form a glass particle deposit 2 around the starting rod 1.

【0012】バーナ5としては同心円状の8重管で形成
され、例えば中心からSiCl4ガス、H2ガス,Ar
ガス,O2ガス(内部火炎を形成する)、その外周にA
rガス,H2ガス,Arガス,O2ガス(外部火炎を形
成する)が供給される。バーナ5によって生成されたガ
ラス微粒子が堆積体2を形成している近傍の温度分布を
サーモトレーサ等の温度測定装置7によって測定する。
The burner 5 is formed of a concentric octuple tube, for example, SiCl4 gas, H2 gas, Ar from the center.
Gas, O2 gas (forming internal flame), A on the outer circumference
R gas, H2 gas, Ar gas, O2 gas (forming an external flame) are supplied. The temperature distribution in the vicinity where the glass particles generated by the burner 5 form the deposit 2 is measured by a temperature measuring device 7 such as a thermotracer.

【0013】ガラス微粒子堆積体2を形成している近傍
の温度分布について調べたところ、図4(a)あるいは
図4(b)に示すように極大点が1つの場合あるいは複
数の場合があり、実線はガラス微粒子堆積体2の表面温
度の最高値THを示す位置より下方で、かつ、本発明の
効果に実質上問題となるガラス微粒子堆積体2の直径が
50%以上となる範囲について示している。堆積体の外
径はレーザ光による通常の方法で測定する(図示せ
ず)。ここで、ガラス微粒子の堆積効率を種々検討した
結果、最高値THと上記の範囲における最小温度TLと
の差△Tとの間に、△T=TH−TL≧60℃の関係を
満たす場合、図5に示すようにガラス微粒子が堆積体2
に吸着する割合が高くなり、ガラス微粒子の堆積速度あ
るいは成長速度が増大することが分かった。また、図4
(b)のように複数の極大値を有する場合は、最高値T
Hと極大値との差が30℃以上であることが均一の母材
を得るために好ましいことが分かった。
When the temperature distribution in the vicinity of the glass particle deposit body 2 is examined, there are cases where there is one or a plurality of maximum points as shown in FIG. 4 (a) or FIG. 4 (b). The solid line indicates below the position where the maximum surface temperature TH of the glass particle deposit 2 is shown, and in the range where the diameter of the glass particle deposit 2 is 50% or more, which is a substantial problem for the effect of the present invention. There is. The outer diameter of the deposit is measured by a usual method using laser light (not shown). Here, as a result of various studies on the deposition efficiency of the glass particles, when the relationship ΔT = TH-TL ≧ 60 ° C. is satisfied between the difference ΔT between the maximum value TH and the minimum temperature TL in the above range, As shown in FIG.
It was found that the rate of adsorption to the glass increased and the deposition rate or growth rate of the glass particles increased. Also, FIG.
When there are multiple maximum values as in (b), the maximum value T
It was found that the difference between H and the maximum value is preferably 30 ° C. or more in order to obtain a uniform base material.

【0014】次に、ガラス微粒子堆積表面の温度分布を
△T≧60℃とするための方法を説明する。(1)同心
状バーナを用いた図1の装置において、予め測定した温
度分布のデータをコンピュータによる制御装置:CPU
9に取り込んでおく。CPU9はこの温度分布に従い、
余剰空気の吸入口3aのクリアランスを変えるとガラス
微粒子堆積体2の下部が冷やされて、△Tを大きくする
ことができる。クリアランスは300〜800mm2の
範囲が好適であり、好ましくは450〜500mm2で
あった。また、吸入口3bから余剰空気を導入する場合
もあるが、空気がバーナ5の火炎と干渉しやすいので吸
入口3aのクリアランスを変えるほうが好ましい。余剰
空気はフィルタを介して外部から空気を導入することに
よって、透明ガラス化するときに発生する気泡を抑制す
ることができる。
Next, a method for making the temperature distribution on the glass particulate deposition surface ΔT ≧ 60 ° C. will be described. (1) In the device of FIG. 1 using a concentric burner, data of temperature distribution measured in advance is controlled by a computer: CPU
Take it in 9. The CPU 9 follows this temperature distribution
When the clearance of the intake port 3a for the excess air is changed, the lower part of the glass particulate deposit body 2 is cooled, and ΔT can be increased. The clearance is preferably in the range of 300 to 800 mm2, and more preferably 450 to 500 mm2. Although excess air may be introduced from the suction port 3b, it is preferable to change the clearance of the suction port 3a because the air easily interferes with the flame of the burner 5. By introducing air from the outside through a filter, the excess air can suppress bubbles generated during vitrification.

【0015】(2)CPU9はガラス微粒子堆積表面の
温度分布に従って、ガス供給装置6の流量を制御し、△
Tを大きくすることができる。例えば、ガラス微粒子堆
積表面の下部の温度が高い場合はバーナに供給する燃料
ガスのうち、外周部の水素ガスを減らすかもしくは酸素
ガスを増やすことにより、外周部火炎の発熱量を下げて
△T≧60℃の条件を満たすことができる。
(2) The CPU 9 controls the flow rate of the gas supply device 6 in accordance with the temperature distribution on the glass particulate deposition surface,
T can be increased. For example, when the temperature of the lower part of the glass particulate deposition surface is high, hydrogen gas in the outer peripheral portion of the fuel gas supplied to the burner is reduced or oxygen gas is increased, thereby lowering the heat generation amount of the outer peripheral flame and reducing ΔT. The condition of ≧ 60 ° C. can be satisfied.

【0016】(3)バーナの外周部を流れる燃料ガスに
対する不活性ガスの比率を上げることにより、実質的に
燃料ガスの流量を減少させ、外周部火炎の発熱量を下げ
て△T≧60℃の条件を満たすことができる。この場
合、合流した後の流量が一定になるように制御すること
によって、安定した火炎を得ることができる。
(3) By increasing the ratio of the inert gas to the fuel gas flowing in the outer peripheral portion of the burner, the flow rate of the fuel gas is substantially reduced, and the heat generation amount of the outer peripheral flame is reduced to ΔT ≧ 60 ° C. Can meet the conditions of. In this case, a stable flame can be obtained by controlling the flow rate after merging to be constant.

【0017】(4)図2に示すように多重管バーナのう
ち、燃料ガスが流れるポートの間隔を偏心させると、間
隔の狭い側を流れるガスの流量が少なくなり、広い側の
温度を上げ、狭い側を下げることができる。偏心させた
管の半径R,軸ずれを△Rとしたとき軸ずれ率:△R/
Rが2%以下であることが好ましい。大きくなると火炎
が不安定となり好ましくない。
(4) In the multi-tube burner as shown in FIG. 2, when the interval of the ports through which the fuel gas flows is eccentric, the flow rate of the gas flowing on the side with the narrow interval decreases and the temperature on the wide side increases. You can lower the narrow side. When the radius R of the eccentric tube is R and the axis deviation is ΔR, the axis deviation rate is ΔR /
R is preferably 2% or less. If it becomes large, the flame becomes unstable, which is not preferable.

【0018】(5)図3に示すように多重管バーナのう
ち、燃料ガスを流がすポートの管に接続されるガス導入
口が対向する位置に複数個設け、一方の側には多く、対
向する側は少なく供給することによって、△Tを調整す
ることができる。
(5) As shown in FIG. 3, in the multi-tube burner, a plurality of gas inlets connected to the pipe of the port through which the fuel gas flows are provided at opposite positions, and a plurality of gas inlets are provided on one side. By supplying a small amount on the opposite side, ΔT can be adjusted.

【0019】[比較例]図1に示した装置と2重火炎を
形成する同心円状の8重管バーナ5を用い、出発ロッド
1がコアとクラッドからなる石英ガラス棒の上に外径1
00mmのガラス微粒子堆積体2を形成した。ガラス微
粒子を堆積するに際し、ガラス原料として四塩化珪素:
3リットル/分、燃料ガスとして水素ガス:20リット
ル/分、酸素ガス:20リットル/分を供給した。8重
管バーナは偏心のないものを用い、余剰空気の吸入口3
aのクリアランスを500mm2、バーナへの各ガスの
供給量は一定に保った。サーモトレーサによってガラス
微粒子が堆積する表面温度をモニタし、また、外径を測
定しながら堆積した。その結果、票に示すように△Tを
大きくすることができず、出発ロッドの引き上げ速度並
びに収率も改善することはできなかった。また、この母
材を1600℃に加熱して透明化したところ、気泡が7
0個発生しており、このうち43個は線引きする時点で
異常が発生し、そのための不良率は18%であった。
Comparative Example Using the apparatus shown in FIG. 1 and a concentric octuple burner 5 forming a double flame, a starting rod 1 has an outer diameter of 1 on a quartz glass rod consisting of a core and a clad.
A glass particle deposit 2 of 00 mm was formed. When depositing glass particles, silicon tetrachloride as a glass raw material:
3 liter / min, hydrogen gas: 20 liter / min and oxygen gas: 20 liter / min were supplied as fuel gas. The octuple burner should have no eccentricity, and the excess air suction port 3
The clearance a was kept at 500 mm 2, and the supply amount of each gas to the burner was kept constant. The surface temperature of the glass particles deposited was monitored by a thermotracer, and the outer diameter was measured while depositing. As a result, as shown in the vote, ΔT could not be increased, and the pulling speed and yield of the starting rod could not be improved. In addition, when the base material was heated to 1600 ° C. to make it transparent, bubbles of 7
There were 0 of them, and 43 of them had an abnormality at the time of drawing, and the defective rate was 18%.

【0020】[実施例1]余剰空気を吸入口3aから導
入し、そのクリアランスを470〜540mm2の範囲
で制御してガラス微粒子堆積体を製造した。その他の条
件は比較例と同じである。この結果、表1に示すように
△Tを大きくすることができ、出発ロッドの引き上げ速
度並びに収率を改善することができた。従来法に比べて
本発明の方法は成長速度で20%以上改善されており、
比較例の場合には気泡が70個発生したが、フィルタを
通して余剰空気を導入したところガラス母材には完全に
不整や気泡がなくなった。
[Example 1] Excess air was introduced from the suction port 3a, and the clearance was controlled in the range of 470 to 540 mm2 to manufacture a glass particulate deposit. The other conditions are the same as those of the comparative example. As a result, ΔT can be increased as shown in Table 1, and the pulling speed and yield of the starting rod can be improved. The growth rate of the method of the present invention is improved by 20% or more as compared with the conventional method.
In the case of the comparative example, 70 bubbles were generated, but when excess air was introduced through the filter, the glass base material was completely free of irregularities and bubbles.

【0021】[実施例2]外周部のポートに供給する燃
料ガスを90〜100%の範囲で制御してガラス微粒子
堆積体を製造した。その他の条件は比較例と同じであ
る。この結果、表1に示す。設定流量の90%以下にす
ると火炎が乱れたり、収率の低下する原因となり、10
0%を越えると温度が上がりすぎるという問題があっ
た。
[Example 2] A glass fine particle deposit was produced by controlling the fuel gas supplied to the port on the outer peripheral portion in the range of 90 to 100%. The other conditions are the same as those of the comparative example. The results are shown in Table 1. If it is less than 90% of the set flow rate, the flame may be disturbed and the yield may be reduced.
If it exceeds 0%, there is a problem that the temperature rises too much.

【0022】[実施例3]同心状の8重管バーナの代わ
りに図2に示すように各ポートの軸を0.5%偏心さ
せ、このバーナのクリアランスの大きい側を出発ロッド
の鉛直上方向に向けてガラス微粒子堆積体を製造した。
その他の条件は比較例と同じである。この結果、表1に
示すように△Tを大きくすることができ、出発ロッドの
引き上げ速度並びに収率を改善することができた。
[Embodiment 3] Instead of the concentric octuple burner, the shaft of each port is eccentric by 0.5% as shown in FIG. 2, and the side with the larger clearance of this burner is directed vertically above the starting rod. A glass fine particle deposit was manufactured for.
The other conditions are the same as those of the comparative example. As a result, ΔT can be increased as shown in Table 1, and the pulling speed and yield of the starting rod can be improved.

【0023】[実施例4]外周部の燃料ポートから噴射
される燃料ガスにアルゴンガスを混合し、供給ガスの総
量を一定に保ちながら燃料ガスの割合を90〜100%
の範囲で制御してガラス微粒子堆積体を製造した。その
他の条件は比較例と同じである。この結果、表1に示す
ように△Tを大きくすることができ、出発ロッドの引き
上げ速度並びに収率を改善することができた。90%以
下になると堆積表面の温度が下がり、収率が低下するの
で好ましくない。
[Embodiment 4] Argon gas is mixed with the fuel gas injected from the fuel port of the outer peripheral portion, and the ratio of the fuel gas is 90 to 100% while keeping the total amount of the supply gas constant.
The glass fine particle deposit was manufactured by controlling within the range. The other conditions are the same as those of the comparative example. As a result, ΔT can be increased as shown in Table 1, and the pulling speed and yield of the starting rod can be improved. When it is 90% or less, the temperature of the deposition surface decreases and the yield decreases, which is not preferable.

【0024】[実施例5]図3に示すように、外周部の
各ポートは両側から燃料ガスが供給される構成とし、2
つの燃料ガスの割合を95〜105%の範囲に制御し、
総流量は比較例の場合と同じに保ちながらガラス微粒子
堆積体を製造した。その他の条件は比較例と同じであ
る。この結果、表1に示すように△Tを大きくすること
ができ、出発ロッドの引き上げ速度並びに収率を改善す
ることができた。
[Embodiment 5] As shown in FIG. 3, each port on the outer peripheral portion has a structure in which fuel gas is supplied from both sides.
Control the ratio of one fuel gas in the range of 95-105%,
The glass particulate deposit was manufactured while keeping the total flow rate the same as that of the comparative example. The other conditions are the same as those of the comparative example. As a result, ΔT can be increased as shown in Table 1, and the pulling speed and yield of the starting rod can be improved.

【表1】 [Table 1]

【0025】[0025]

【発明の効果】以上説明したように本発明に係わる光フ
ァイバ用母材の製造方法は、ガラス微粒子の堆積中にそ
の表面温度の最高値と最低値の差が60℃以上であるよ
うに制御するので、その結果、サーモホレシス効果が向
上してガラス微粒子の堆積効率を上げることができる。
また、フィルタによって余剰空気内に含まれる異物を除
去することにより、気泡の発生頻度を低減することがで
きる。さらに、本発明の製造装置、特にガラス微粒子の
表面温度が最小となる近傍に余剰空気を導入するための
吸入口が設けられ、又多重管バーナは温度差を生じる構
成となっているために、サーモホレシス効果を増大さ
せ、高収率に母材を製造することができる。
As described above, in the method for producing a base material for an optical fiber according to the present invention, the difference between the maximum value and the minimum value of the surface temperature of the glass particles is controlled to be 60 ° C. or more during the deposition. As a result, the thermophoresis effect is improved, and the deposition efficiency of the glass particles can be increased.
Further, by removing the foreign matter contained in the surplus air with the filter, the frequency of bubble generation can be reduced. Further, since the manufacturing apparatus of the present invention, in particular, the suction port for introducing the excess air is provided in the vicinity where the surface temperature of the glass particles is minimized, and the multi-tube burner is configured to cause a temperature difference, The thermophoresis effect can be increased, and the base material can be produced in high yield.

【図面の簡単な説明】[Brief description of drawings]

【図1】本発明に係わる光ファイバ用母材の製造装置の
構成を示す概略図である。
FIG. 1 is a schematic diagram showing a configuration of an optical fiber preform manufacturing apparatus according to the present invention.

【図2】本発明に係わる偏心バーナの横断面図である。FIG. 2 is a cross-sectional view of an eccentric burner according to the present invention.

【図3】本発明に係わる複数のガス導入口を有するバー
ナの横断面図である。
FIG. 3 is a cross-sectional view of a burner having a plurality of gas introduction ports according to the present invention.

【図4】ガラス微粒子堆積体の温度分布の測定例であ
る。
FIG. 4 is a measurement example of a temperature distribution of a glass particle deposit.

【図5】ガラス微粒子堆積体の△Tと成長速度の関係を
示した図である。
FIG. 5 is a diagram showing the relationship between ΔT and growth rate of a glass particulate deposit.

【符号の説明】[Explanation of symbols]

1:出発ロッド 2:ガラス微粒子堆積体 3:空気の吸入口 4:排気口 5:ガラス微粒子堆積体用バーナ 6:ガス供給装置 7:温度測定装置 8:反応容器 9:CPU 10:取込み口 1: Starting Rod 2: Glass Particle Deposited Body 3: Air Intake Port 4: Exhaust Port 5: Glass Particle Deposited Body Burner 6: Gas Supply Device 7: Temperature Measuring Device 8: Reaction Vessel 9: CPU 10: Intake Port

Claims (8)

【特許請求の範囲】[Claims] 【請求項1】 容器内に垂直方向に移動可能に把持さ
れ、軸回りに回転する出発ロッドの上部から下部に向か
ってガラス微粒子体を積層する光ファイバ用母材の製造
方法であって、 容器内にフィルタを通過させた清浄な
余剰空気を導入すると共に、ガラス微粒子体の表面温度
の最高値を示す位置より下方で、かつ、ガラス微粒子体
の直径の50%の径を有する範囲において、ガラス微粒
子体の表面温度の最高値と最低値の差が60℃以上であ
るように制御することを特徴とする光ファイバ用母材の
製造方法。
1. A method for producing an optical fiber preform in which glass microparticles are laminated from an upper portion to a lower portion of a starting rod which is movably held in a container in a vertical direction and rotates about an axis, the container comprising: Introducing clean excess air that has passed through a filter into the inside of the glass in the range below the position where the maximum surface temperature of the glass particulates is shown and having a diameter of 50% of the diameter of the glass particulates. A method for producing an optical fiber preform, wherein the difference between the maximum value and the minimum value of the surface temperature of the fine particles is controlled to be 60 ° C. or more.
【請求項2】 容器内に垂直方向に移動可能に把持さ
れ、軸回りに回転する出発ロッドの上部から下部に向か
ってガラス微粒子体を積層する光ファイバ用母材の製造
方法であって、 容器内にフィルタを通過させた清浄な
余剰空気を導入すると共に、ガラス微粒子体の表面温度
の最高値を示す位置より下方で、かつ、ガラス微粒子体
の直径の50%の径を有する範囲において、表面温度が
極大値を有する場合は最高値と極小値の差が60℃以上
であるように制御することを特徴とする光ファイバ用母
材の製造方法。
2. A method for producing an optical fiber preform, in which glass microparticles are laminated from the upper part to the lower part of a starting rod that is vertically movably held in a container and rotates around an axis, the container comprising: Introducing clean surplus air that has passed through a filter into the inside of the surface of the fine glass particles below a position where the maximum surface temperature of the fine glass particles is present and having a diameter of 50% of the diameter of the fine glass particles. When the temperature has a maximum value, the difference between the maximum value and the minimum value is controlled so as to be 60 ° C. or more, and the method for producing an optical fiber preform.
【請求項3】 容器内に導入する余剰空気をガラス微粒
子体の下部に導き、該余剰空気の流量を調整してガラス
微粒子体の温度を制御することを特徴とする請求項1又
は2に記載の光ファイバ用母材の製造方法。
3. The method according to claim 1, wherein the excess air introduced into the container is guided to the lower portion of the glass fine particle body, and the temperature of the glass fine particle body is controlled by adjusting the flow rate of the excess air. Manufacturing method of optical fiber preform.
【請求項4】 ガラス微粒子を生成するバーナは多重管
構造をなし、各ポートからは独立にガス量を制御して流
出させることができ、外周部のポートに供給する燃料ガ
スを90〜100%の範囲で制御することを特徴とする
請求項1又は2に記載の光ファイバ用母材の製造方法。
4. A burner for producing fine glass particles has a multi-tube structure, and the amount of gas can be independently controlled to flow out from each port, and 90% to 100% of the fuel gas supplied to the port on the outer peripheral portion can be discharged. The method for producing an optical fiber preform according to claim 1 or 2, wherein the method is controlled within the range.
【請求項5】 ガラス微粒子を生成するバーナは多重管
構造をなし、少なくとも1つのガス流出ポートを偏心し
て構成し、偏心したポートからは燃料ガスが流出するこ
とを特徴とする請求項1又は2に記載の光ファイバ用母
材の製造方法。
5. The burner for producing fine glass particles has a multi-tube structure, at least one gas outflow port is eccentrically configured, and the fuel gas flows out from the eccentric port. A method for manufacturing a base material for an optical fiber according to.
【請求項6】 ガラス微粒子を生成するバーナは多重管
構造をなし、少なくとも1つの管に接続されるガス導入
口が複数個設けられ、該複数のガス導入口から夫々燃料
ガスを供給することを特徴とする請求項1又は2に記載
の光ファイバ用母材の製造方法。
6. A burner for producing fine glass particles has a multi-tube structure, is provided with a plurality of gas introduction ports connected to at least one pipe, and supplies a fuel gas from each of the plurality of gas introduction ports. The method for producing a preform for an optical fiber according to claim 1 or 2.
【請求項7】 ガラス微粒子を生成するバーナは多重管
構造をなし、各ポートからは独立にガス量を制御して流
出させることができ、少なくとも燃料ガス、不活性ガス
が合流した後の流量を一定に保ちつつ、不活性ガスに対
する燃料ガスの割合をかえることを特徴とする請求項1
又は2に記載の光ファイバ用母材の製造方法。
7. The burner for producing glass fine particles has a multi-tube structure, and the gas amount can be independently controlled to flow out from each port, and at least the flow rate after the fuel gas and the inert gas have joined together can be controlled. 2. The ratio of the fuel gas to the inert gas is changed while keeping it constant.
Or the manufacturing method of the optical fiber preform according to 2.
【請求項8】 反応容器と、反応容器の上部を貫通して
上下方向及び軸回りに移動又は回転可能に設けられた出
発ロッドと、ガラス微粒子を生成するバーナと、外部か
ら空気を取り入れる吸入口と、バーナと対向する位置に
設けられた排気口とを備え、出発ロッドの上部から下部
に向かってガラス微粒子を積層する光ファイバ用母材の
製造装置であって、外部空気の取込み口には空気中の浮
遊異物を除去するフィルタを備え、ガラス微粒子体の表
面温度の最高値を示す位置より下方で、かつ、ガラス微
粒子体の直径の50%の径を有する範囲において、ガラ
ス微粒子体の表面温度の最高値と最低値の差が60℃以
上であるように調整するための温度制御装置及びガラス
微粒子体の外径を測定するための外径測定装置を有する
ことを特徴とする光ファイバ用母材の製造装置。
8. A reaction container, a starting rod penetrating the upper part of the reaction container so as to be movable or rotatable in the vertical direction and around the axis, a burner for generating glass particles, and an intake port for taking in air from the outside. And an exhaust port provided at a position facing the burner, which is an apparatus for manufacturing an optical fiber preform for laminating glass fine particles from the upper part to the lower part of a starting rod, wherein an external air intake port is provided. The surface of the glass particle body is provided with a filter for removing suspended foreign matters in the air, below the position where the maximum surface temperature of the glass particle body is shown, and in a range having a diameter of 50% of the diameter of the glass particle body. A light having a temperature control device for adjusting the difference between the maximum value and the minimum value of the temperature to be 60 ° C. or more and an outer diameter measuring device for measuring the outer diameter of the glass fine particles. Manufacturing equipment for fiber preform.
JP22908595A 1995-09-06 1995-09-06 Production of preformed material for optical fiber and production unit therefor Pending JPH0971430A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP22908595A JPH0971430A (en) 1995-09-06 1995-09-06 Production of preformed material for optical fiber and production unit therefor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP22908595A JPH0971430A (en) 1995-09-06 1995-09-06 Production of preformed material for optical fiber and production unit therefor

Publications (1)

Publication Number Publication Date
JPH0971430A true JPH0971430A (en) 1997-03-18

Family

ID=16886522

Family Applications (1)

Application Number Title Priority Date Filing Date
JP22908595A Pending JPH0971430A (en) 1995-09-06 1995-09-06 Production of preformed material for optical fiber and production unit therefor

Country Status (1)

Country Link
JP (1) JPH0971430A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10308541B2 (en) 2014-11-13 2019-06-04 Gerresheimer Glas Gmbh Glass forming machine particle filter, a plunger unit, a blow head, a blow head support and a glass forming machine adapted to or comprising said filter
JP2020090427A (en) * 2018-12-07 2020-06-11 古河電気工業株式会社 Burner for porous body synthesis and method of manufacturing porous body

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10308541B2 (en) 2014-11-13 2019-06-04 Gerresheimer Glas Gmbh Glass forming machine particle filter, a plunger unit, a blow head, a blow head support and a glass forming machine adapted to or comprising said filter
JP2020090427A (en) * 2018-12-07 2020-06-11 古河電気工業株式会社 Burner for porous body synthesis and method of manufacturing porous body

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