JPS63159232A - Production apparatus for optical fiber preform - Google Patents
Production apparatus for optical fiber preformInfo
- Publication number
- JPS63159232A JPS63159232A JP30605886A JP30605886A JPS63159232A JP S63159232 A JPS63159232 A JP S63159232A JP 30605886 A JP30605886 A JP 30605886A JP 30605886 A JP30605886 A JP 30605886A JP S63159232 A JPS63159232 A JP S63159232A
- Authority
- JP
- Japan
- Prior art keywords
- exhaust
- chamber
- inert gas
- sintering
- pressure
- 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
Links
- 239000013307 optical fiber Substances 0.000 title claims abstract description 32
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 11
- 238000005245 sintering Methods 0.000 claims abstract description 57
- 239000011261 inert gas Substances 0.000 claims abstract description 44
- 238000005192 partition Methods 0.000 claims description 5
- 230000007423 decrease Effects 0.000 claims description 3
- 238000000638 solvent extraction Methods 0.000 claims description 2
- 239000012535 impurity Substances 0.000 abstract description 7
- 239000007789 gas Substances 0.000 description 32
- 239000000463 material Substances 0.000 description 10
- 239000004071 soot Substances 0.000 description 8
- 230000018044 dehydration Effects 0.000 description 7
- 238000006297 dehydration reaction Methods 0.000 description 7
- 238000000034 method Methods 0.000 description 7
- 238000004017 vitrification Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- YBMRDBCBODYGJE-UHFFFAOYSA-N germanium dioxide Chemical compound O=[Ge]=O YBMRDBCBODYGJE-UHFFFAOYSA-N 0.000 description 4
- 229910021645 metal ion Inorganic materials 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 239000002019 doping agent Substances 0.000 description 3
- 229910052734 helium Inorganic materials 0.000 description 3
- 239000012024 dehydrating agents Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000005660 chlorination reaction Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 239000005373 porous glass Substances 0.000 description 1
- 230000010349 pulsation Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000029058 respiratory gaseous exchange Effects 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
- C03B37/01—Manufacture of glass fibres or filaments
- C03B37/012—Manufacture of preforms for drawing fibres or filaments
- C03B37/014—Manufacture 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]
- C03B37/01446—Thermal after-treatment of preforms, e.g. dehydrating, consolidating, sintering
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
- C03B37/01—Manufacture of glass fibres or filaments
- C03B37/012—Manufacture of preforms for drawing fibres or filaments
- C03B37/014—Manufacture 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]
- C03B37/01446—Thermal after-treatment of preforms, e.g. dehydrating, consolidating, sintering
- C03B37/0146—Furnaces therefor, e.g. muffle tubes, furnace linings
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、光フアイバ母材スートを脱水ガラス化して光
フアイバ母材を得る光ファイバ母材製造Ｓ！四に関する
ものである。DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention is directed to optical fiber preform production S! in which an optical fiber preform is obtained by dehydrating and vitrifying an optical fiber preform soot! This is related to the fourth issue.
（従来技術とその問題点）
光ファイバの母材を製造する方法として、＄１０２に屈
折率調整用のドーパントとしてのＧｅＯ２を分布させた
多孔質ガラス微粒体からなる光フアイバ母材スートを、
焼結炉で焼結して脱水ガラス化づ′る方法がある。(Prior art and its problems) As a method for manufacturing an optical fiber base material, an optical fiber base material suit consisting of porous glass fine particles in which GeO2 as a dopant for adjusting the refractive index is distributed in $102 is used.
There is a method of dehydration and vitrification by sintering in a sintering furnace.
この様な方法により光フアイバ母材を製造するには、従
来第２図に示すように、光ファイバは材スート５０を先
端部に形成した石英ガラスからなる種棒５１を先端側か
ら焼結炉の炉心管５２に挿入し、炉心管５２の下端から
Ｈｅガスと脱水剤としてのＣ１２ガスとを供給し、種棒
５１を回転させながら徐々に下降させ、ヒータ５３によ
り加熱することにより光フアイバ母材スート５０を脱水
ガラス化して光フアイバ母材５４を得ていた。そして炉
心管５２内のＨｅ及びＣ１２ガスは、排気筒体５５に接
続された排気流路５６を介して排気処理装置により吸引
していた。なお炉心管５２の内部と排気筒体５５の内部
とは蓋体５７により区画され、排気筒体５５の内部と大
気との間は蓋体５８により区画されており、蓋体５７及
び蓋体５８には種棒５１が貫通する透孔が穿設されてい
る。In order to manufacture an optical fiber base material by such a method, conventionally, as shown in FIG. Helium gas and C12 gas as a dehydrating agent are supplied from the lower end of the furnace core tube 52, the seed rod 51 is rotated and gradually lowered, and heated by the heater 53 to form an optical fiber motherboard. The optical fiber base material 54 was obtained by dehydrating and vitrifying the material soot 50. The He and C12 gases in the reactor core tube 52 were sucked by an exhaust treatment device through an exhaust flow path 56 connected to the exhaust cylinder body 55. Note that the inside of the reactor core tube 52 and the inside of the exhaust cylinder 55 are partitioned by a lid 57, and the inside of the exhaust cylinder 55 and the atmosphere are partitioned by a lid 58. A through hole is bored through the seed rod 51.
また排気流路５６には手動バルブ５９が設置されている
。Further, a manual valve 59 is installed in the exhaust flow path 56.
しかし、炉心管５２の内圧は、排気側吸引圧の変動や、
種棒５１のゆがみや径の不均一に起因する種棒５１と蓋
体５７との間隙の変化や、炉心管５２内部の温度変化に
よる排気ガス実体積の変動等により変動する。However, the internal pressure of the reactor core tube 52 is affected by fluctuations in the suction pressure on the exhaust side,
It fluctuates due to changes in the gap between the seed rod 51 and the lid body 57 due to distortion or nonuniform diameter of the seed rod 51, and fluctuations in the actual volume of exhaust gas due to temperature changes inside the core tube 52.
このように炉心管５２の内圧が変化すれば、光フアイバ
母材スート５０の脱水ガラス化工程中に脱水効果が変動
し、光フアイバ母材５４から得られる光ファイバの長手
方向の損失特性が低下する。If the internal pressure of the reactor core tube 52 changes in this way, the dehydration effect will vary during the dehydration and vitrification process of the optical fiber preform soot 50, and the loss characteristics in the longitudinal direction of the optical fiber obtained from the optical fiber preform 54 will deteriorate. do.
また脱水ガラス化工程中に屈折率調整用のドーパントと
してのＧｅＯ２の一部が塩化反応により飛散して所望の
屈折率になるのであるが、炉心管５２の内圧変動により
この反応速度即ち飛散量が変化し、その結果、光フアイ
バ母材５４の屈折率差や屈折率分布形状が長手方向に変
化し、光フアイバ母材５４から得られる光ファイバの伝
送特性が低下する。また炉心管５２の内圧と炉シールガ
ス圧との差が±２０履Ｈ２０以上の状態で運転すると、
長時間の脱水ガラス化工程中に炉心管５２が変形し、破
壊に至る。またたとえば排気負圧変動が激しい場合は、
ガス流の脈動現象が起こり、蓋体５７の透孔部で吸排交
番（息つき）し、炉心管５２内に排気が逆流して、外部
から空気や金属イオン等の不純物が侵入する危険性があ
る。Also, during the dehydration and vitrification process, a part of GeO2 as a dopant for adjusting the refractive index is scattered due to the chlorination reaction to achieve the desired refractive index, but due to internal pressure fluctuations in the core tube 52, the rate of this reaction, that is, the amount of scattering is As a result, the refractive index difference and the refractive index distribution shape of the optical fiber preform 54 change in the longitudinal direction, and the transmission characteristics of the optical fiber obtained from the optical fiber preform 54 deteriorate. In addition, if the operation is performed in a state where the difference between the internal pressure of the furnace core tube 52 and the furnace seal gas pressure is ±20 mm or more,
During the long dehydration and vitrification process, the furnace core tube 52 deforms and breaks. For example, if the exhaust negative pressure fluctuates rapidly,
A pulsation phenomenon occurs in the gas flow, and the gas flow alternates between suction and exhaust (breathing) at the through hole of the lid body 57, and the exhaust gas flows back into the reactor core tube 52, creating a risk of impurities such as air and metal ions entering from the outside. be.
しかしながら従来の光フアイバ母材製造装置では、手動
バルブ５９の開度を調整して排気ガスの総量を変えるこ
とにより炉心管５２の内圧を調整し、安定化していたの
で、排気側の吸引圧の変動等に対応することができず、
炉心管５２の内圧を一定にすることができないという問
題があった。However, in the conventional optical fiber base material manufacturing equipment, the internal pressure of the reactor core tube 52 was adjusted and stabilized by adjusting the opening degree of the manual valve 59 and changing the total amount of exhaust gas. Unable to respond to changes, etc.
There was a problem in that the internal pressure of the furnace core tube 52 could not be made constant.
（問題点を解決するための手段）
上記問題点を解決するため、本発明の光フアイバ母材製
造装置は、焼結炉の焼結室を形成する炉心管の上側に配
置されて第１の排気室を形成する第１の排気筒体と、こ
の第１の排気筒体の上側に配置されて第２の排気室を形
成する第２の排気筒体と、種棒が貫通する透孔を有し且
つ前記焼結室と第１の排気室とを区画する第１の蓋体と
、前記種棒が貫通する透孔を有し且つ前記第１の排気室
と第２の排気室とを区画する第２の蓋体と、前記種棒が
貫通する透孔を有し且つ前記第２の排気室と外部とを区
画する第３の蓋体と、前記第２の排気室に不活性ガスを
供給する不活性ガス供給流路と、この不活性ガス供給流
路に配置された流量調節弁と、前記焼結室の圧力を検出
する圧力検出器と、この圧力検出温からの信号により前
記焼結室の圧力に応じて前記流量調節弁を制御する制御
装置と、前記第１の排気室と排気処理装置とを連通させ
る排気流路とを設け、前記焼結室の圧力が増加したとき
には前記第２の排気室に供給する不活性ガスの量を減少
させ、前記焼結室の圧力が減少したときには前記第２の
排気室に供給する不活性ガスの是を増加させる構成とし
たものである。(Means for Solving the Problems) In order to solve the above problems, the optical fiber preform manufacturing apparatus of the present invention is arranged above the core tube forming the sintering chamber of the sintering furnace, A first exhaust cylinder body forming an exhaust chamber, a second exhaust cylinder body disposed above the first exhaust cylinder body forming a second exhaust chamber, and a through hole through which the seed rod passes. a first lid body that has a first lid body that partitions the sintering chamber and a first exhaust chamber; and a first lid body that has a through hole through which the seed rod passes and that divides the first exhaust chamber and the second exhaust chamber. a third lid having a through hole through which the seed rod passes and partitioning the second exhaust chamber from the outside; and a third lid that partitions the second exhaust chamber with an inert gas. an inert gas supply channel for supplying the sintering chamber, a flow control valve disposed in the inert gas supply channel, a pressure detector for detecting the pressure in the sintering chamber, and a signal from the detected pressure temperature to detect the pressure in the sintering chamber. A control device that controls the flow rate adjustment valve according to the pressure in the sintering chamber, and an exhaust flow path that communicates the first exhaust chamber and the exhaust treatment device are provided, and when the pressure in the sintering chamber increases, The amount of inert gas supplied to the second exhaust chamber is reduced, and when the pressure in the sintering chamber decreases, the amount of inert gas supplied to the second exhaust chamber is increased. be.
（作用）
焼結室に供給されたガスは、第１の蓋体と種棒との間隙
から第１の排気室に至り、排気処理装置により排気流路
を通って吸引排気される。そして焼結室の圧力は圧力検
出器により検出され、制御装置は圧力検出器からの信号
に応じて流量調節弁を制御して、焼結室の圧力が増加し
たときには第２の排気室に供給する不活性ガスの量を減
少させ、焼結室の圧力が減少したときには第２の排気室
に供給する不活性ガスの偵を増加させて、炉心管の内圧
を一定に保つ。(Function) The gas supplied to the sintering chamber reaches the first exhaust chamber through the gap between the first lid and the seed rod, and is sucked and exhausted through the exhaust flow path by the exhaust treatment device. Then, the pressure in the sintering chamber is detected by a pressure detector, and the control device controls the flow control valve according to the signal from the pressure detector, so that when the pressure in the sintering chamber increases, the pressure is supplied to the second exhaust chamber. When the pressure in the sintering chamber decreases, the amount of inert gas supplied to the second exhaust chamber is increased to keep the internal pressure of the furnace tube constant.
（実施例） 以下、本発明の一実施例を第１図に基づいて説明する。(Example) An embodiment of the present invention will be described below with reference to FIG.
第１図は本発明の一実施例における光フアイバ母材製造
装置の概略構成図で、１は焼結炉の炉心管であり、この
炉心管１には、下端からＨｅガスと脱水剤としてのＣＩ
□ガスとが供給され、また先端に光フアイバ母材スート
２が形成された種棒３の先端部が上側から挿入されてい
る。また前記炉心管１は、中間部適所の外側にカーボン
ヒータ等のヒータ４が設置されており、上側に例えば石
英ガラス等からなる第１の排気筒体５が連結されている
。この第１の排気筒体５の上には第２の排気筒体６が一
体に形成されており、前記第１の排気筒体５の側面には
管状のガス排出部７が突設され、前記第２の排気筒体６
の側面には管状の不活性ガス導入部８が突設されている
。前記第１の排気筒体５の下端フランジ部には第１の蓋
体９が、前記第２の排気筒体６の下端７ランジ部には第
２の蓋体１０が、前記第２の排気筒体６の上端フランジ
部には第３の蓋体１１がそれぞれ載置されている。これ
ら第１〜第３の蓋体９〜１１は、周方向２つ割りの円板
状で、中心部に前記種棒３が１通ずる透孔１２〜１４を
有している。前記第１の蓋体９は前記炉心管１により形
成される焼結室１５と前記第１の排気筒体５により形成
される第１の排気室１６とを区画しており、前記第２の
蓋体９は前記第１の排気室１６と前記第２の排気筒体６
により形成される第２の排気室１７とを区画しており、
前記第３の蓋体１１は前記第２の排気室１７と大気とを
区画している。前記焼結室１５は、一端が閉塞された管
路１８に連通しており、この管路１８には指示計器付の
圧力検出１１９が設置されている。この圧力検出器１９
は制御装置２０に接続されており、圧力検出器１９と制
御装置２０との接続点には設定器２１が接続されている
。FIG. 1 is a schematic configuration diagram of an optical fiber preform manufacturing apparatus according to an embodiment of the present invention, and 1 is a core tube of a sintering furnace. C.I.
□ gas is supplied, and the tip of a seed rod 3 having an optical fiber base material soot 2 formed at its tip is inserted from above. Further, in the furnace core tube 1, a heater 4 such as a carbon heater is installed outside at a proper position in the middle portion, and a first exhaust cylinder body 5 made of, for example, quartz glass is connected to the upper side. A second exhaust cylinder 6 is integrally formed on the first exhaust cylinder 5, and a tubular gas discharge part 7 is protruded from the side surface of the first exhaust cylinder 5. Said second exhaust cylinder body 6
A tubular inert gas introduction part 8 is provided protruding from the side surface of the inert gas introduction part 8. A first lid body 9 is attached to the lower end flange portion of the first exhaust tube body 5, a second lid body 10 is attached to the lower end 7 flange portion of the second exhaust tube body 6, and a second lid body 10 is attached to the lower end flange portion of the second exhaust tube body 6. Third lid bodies 11 are placed on the upper end flange portions of the cylinder body 6, respectively. These first to third lid bodies 9 to 11 have a disc shape divided into two in the circumferential direction, and have through holes 12 to 14 in the center through which the seed rod 3 passes. The first lid body 9 partitions a sintering chamber 15 formed by the furnace core tube 1 and a first exhaust chamber 16 formed by the first exhaust cylinder body 5. The lid body 9 connects the first exhaust chamber 16 and the second exhaust cylinder body 6.
and a second exhaust chamber 17 formed by
The third lid 11 separates the second exhaust chamber 17 from the atmosphere. The sintering chamber 15 communicates with a conduit 18 whose one end is closed, and a pressure detector 119 with an indicator is installed in this conduit 18. This pressure detector 19
is connected to a control device 20, and a setting device 21 is connected to a connection point between the pressure detector 19 and the control device 20.
前記不活性ガス導入部８は不活性ガス供給流路２２を介
して図外の不活性ガス供給装置に接続されており、不活
性ガス供給流路２２には前記制御装置２０により制御さ
れる流ｍ＊節弁２３が設置されている。前記ガス排出部
７は先端部が排気箱２４に貫入しており、この排気箱２
４は不活性ガス流入部２５と排気ガス流出部２６とを有
している。The inert gas introduction section 8 is connected to an inert gas supply device (not shown) via an inert gas supply channel 22, and the inert gas supply channel 22 has a flow controlled by the control device 20. An m* moderation valve 23 is installed. The tip of the gas exhaust section 7 penetrates into the exhaust box 24, and the gas exhaust section 7 penetrates into the exhaust box 24.
4 has an inert gas inlet 25 and an exhaust gas outlet 26.
前記不活性ガス流入部２５は図外の管路を介して前記不
活性ガス供給装置に接続されており、前記排気ガス流出
部２６は排気流路２７を介して排気処理装置２８に接続
されている。なお２９は光ファイバ母材スート２が脱水
ガラス化されてできた光フアイバ母材である。The inert gas inlet 25 is connected to the inert gas supply device via a pipe (not shown), and the exhaust gas outlet 26 is connected to an exhaust treatment device 28 via an exhaust flow path 27. There is. Note that 29 is an optical fiber preform made by dehydrating and vitrifying the optical fiber preform soot 2.
次に作用を説明する。まず第１〜第３のａ体９〜１１を
取外しておき、先端部に光フアイバ母材スート２を形成
した種棒３を先端側を下向きにして図外のチャック装置
に装着する。そして光フアイバ母材スート２部分が焼結
室１５の上端部に位置するように種棒３を下降させ、第
１の蓋体９を第１の排気筒体５の下端７ランジ部に載置
し、第２の蓋体１０を第２の排気筒体６の下端７ランジ
部に載置し、第３の蓋体１１を第２の排気筒体６の上端
フランジ部に載置する。この状態で焼結室１５にＨｅガ
ス及び脱水剤としてのＣＩ２ガスを供給し、ヒータ４で
焼結室１５を加熱して、種棒３を軸芯回りに回転させな
がら徐々に下降させると、光フアイバ母材スート２が先
端側から徐々に脱水ガラス化されて体積が減少し、光フ
ァイバ母材２９になる。このとき、焼結室１５に供給さ
れたガスは、種棒３と第１の蓋体９との間隙から第１の
排気室１６に流入し、ガス排出部７を通って排気される
。そして、焼結室１５の内圧が圧力検出器１９により検
出され、圧力検出器１９の信号が制御装設２０に供給さ
れて、それにより制御装置２０は流量調節弁２３を制御
する。即ち、焼結室１５の内圧が設定器２１で設定した
設定値よりも大きい場合、制御装置２０は流量調節弁２
３を絞って排気室１５へのＨｅ或はＡｒ等或はこれらを
混合した不活性ガスの流入面を減少させ、逆に焼結室１
５の内圧が設定器２１で設定した設定値よりも小さい場
合、制御装置２０は流量調節弁２３を更に開放して第２
の排気室１７への不活性ガスの流入量を増加させる。こ
れにより第２の排気室１７の内圧が制御され、第２の排
気室１７から種棒３と第２の蓋体１０との間隙を通って
第１の排気室１６に流入する不活性ガスの流通が変化し
、これにより第１の排気室１６の内圧が変化し、焼結室
１５から種棒３と第１の蓋体９との間隙を通って第１の
排気室１６に流入する排気ガスの流量が変化して、焼結
室１５の内圧が一定に保たれる。Next, the effect will be explained. First, the first to third A bodies 9 to 11 are removed, and the seed rod 3 having the optical fiber base material soot 2 formed at its tip is mounted on a chuck device (not shown) with its tip facing downward. Then, the seed rod 3 is lowered so that the optical fiber base material soot 2 portion is located at the upper end of the sintering chamber 15, and the first lid body 9 is placed on the lower end 7 flange portion of the first exhaust cylinder body 5. Then, the second lid body 10 is placed on the lower end 7 flange portion of the second exhaust cylinder body 6, and the third lid body 11 is placed on the upper end flange portion of the second exhaust cylinder body 6. In this state, He gas and CI2 gas as a dehydrating agent are supplied to the sintering chamber 15, the sintering chamber 15 is heated by the heater 4, and the seed rod 3 is gradually lowered while rotating around its axis. The optical fiber preform soot 2 is gradually dehydrated and vitrified from the tip side to reduce its volume and become an optical fiber preform 29. At this time, the gas supplied to the sintering chamber 15 flows into the first exhaust chamber 16 through the gap between the seed rod 3 and the first lid 9 and is exhausted through the gas exhaust section 7. Then, the internal pressure of the sintering chamber 15 is detected by a pressure detector 19, and a signal from the pressure detector 19 is supplied to a control device 20, whereby the control device 20 controls the flow rate regulating valve 23. That is, when the internal pressure of the sintering chamber 15 is greater than the set value set by the setting device 21, the control device 20 controls the flow rate control valve 2.
3 to reduce the inflow surface of an inert gas such as He or Ar or a mixture of these into the exhaust chamber 15, and conversely, the sintering chamber 1
5 is smaller than the set value set by the setting device 21, the control device 20 further opens the flow rate control valve 23 to open the second flow control valve 23.
The amount of inert gas flowing into the exhaust chamber 17 is increased. As a result, the internal pressure of the second exhaust chamber 17 is controlled, and the inert gas flowing from the second exhaust chamber 17 into the first exhaust chamber 16 through the gap between the seed rod 3 and the second lid 10 is controlled. The flow changes, thereby changing the internal pressure of the first exhaust chamber 16, and the exhaust gas flowing from the sintering chamber 15 into the first exhaust chamber 16 through the gap between the seed rod 3 and the first lid body 9. The internal pressure of the sintering chamber 15 is kept constant by changing the gas flow rate.
一方、ガス排出部７から排気箱２４の内部に流入した排
気ガスと不活性ガスとの混合排気ガスは、不活性ガス流
入部２５から供給されるＨｅ或はＡｒ等或はこれらの混
合ガスからなる不活性ガスとともに排気ガス流出部２６
から吸引排気される。On the other hand, the mixed exhaust gas of exhaust gas and inert gas that has flowed into the inside of the exhaust box 24 from the gas discharge section 7 is mixed with He, Ar, etc., or a mixture thereof supplied from the inert gas inflow section 25. Exhaust gas outlet 26 together with inert gas
It is sucked and exhausted from.
このように、焼結室１５の内圧を検出してそれに応じて
第２の排気室１７に供給する不活性ガスの流量を制御し
ているので、焼結室１５の内圧を常に一定に保つことが
できる。しかも第２の排気室１７を介して第１の排気室
１６に不活性ガスを供給しているので、第１の排気室１
６の排気ガスは不活性ガスによりガス排出部７から排気
箱２４側へ押出され、第１の排気室１６には不活性ガス
が充満しているので、たとえ焼結室１５の内圧が変動し
て焼結室１５に第１の排気室１６からガスが逆流しても
、焼結室１５に空気或は金属イオン等の不純物が侵入す
ること全くない。特に、排気室を第１の排気室１６と第
２の排気室１７との２段構造としているので、焼結室１
５と大気との間の遮断は完璧であり、焼結室１５に空気
が侵入するのを確実に阻止できる。しかも本実施例では
排気箱２４を設け、この内部にも不活性ガス流入部２５
から不活性ガスを供給しているので、排気室１５及び排
気箱２４の内部には不活性ガスが充満しており、焼結室
１５への不純物の侵入をより確実に防止できる。この排
気箱２４は、排気流路２７を構成する管路内の金属イオ
ン等の不純物が焼結室１５に侵入するのを防止するのに
特に有効である。In this way, since the internal pressure of the sintering chamber 15 is detected and the flow rate of the inert gas supplied to the second exhaust chamber 17 is controlled accordingly, the internal pressure of the sintering chamber 15 can always be kept constant. I can do it. Moreover, since the inert gas is supplied to the first exhaust chamber 16 via the second exhaust chamber 17, the first exhaust chamber 1
The exhaust gas of No. 6 is pushed out from the gas exhaust part 7 to the exhaust box 24 side by the inert gas, and the first exhaust chamber 16 is filled with the inert gas, so even if the internal pressure of the sintering chamber 15 fluctuates. Even if gas flows back into the sintering chamber 15 from the first exhaust chamber 16, no impurities such as air or metal ions will enter the sintering chamber 15. In particular, since the exhaust chamber has a two-stage structure of the first exhaust chamber 16 and the second exhaust chamber 17, the sintering chamber 1
5 and the atmosphere is perfect, and air can be reliably prevented from entering the sintering chamber 15. Moreover, in this embodiment, an exhaust box 24 is provided, and an inert gas inlet 25 is also provided inside this box.
Since the inert gas is supplied from the inside of the exhaust chamber 15 and the exhaust box 24, the inert gas is filled inside the exhaust chamber 15 and the exhaust box 24, and it is possible to more reliably prevent impurities from entering the sintering chamber 15. This exhaust box 24 is particularly effective in preventing impurities such as metal ions in the pipe constituting the exhaust flow path 27 from entering the sintering chamber 15.
（別の実施例）
上記実施例においては、設定器２１により焼結室１５の
内圧の基準値を設定できるように構成したが、焼結室１
５の内圧の基準値が常に一定で変化させる必要のない場
合には、設定器２１は設けなくてもよい。(Another Example) In the above example, the reference value of the internal pressure of the sintering chamber 15 can be set using the setting device 21.
If the reference value of the internal pressure 5 is always constant and does not need to be changed, the setting device 21 may not be provided.
また上記実施例においては、排気箱２４を設けて焼結室
１５への不純物の侵入をより確実に防止できるようにし
ているが、この排気箱２４は必ずしも設Ｇノる必要はな
い。Further, in the above embodiment, the exhaust box 24 is provided to more reliably prevent impurities from entering the sintering chamber 15, but the exhaust box 24 does not necessarily have to be provided.
（発明の効果）
以上説明したように本発明によれば、焼結室の内圧を圧
力検出器で検出してそれに応じて制御装置により流量調
節弁を制御することにより第２の排気室に供給する不活
性ガスの流量を制御しているので、焼結室の内圧を常に
一定に保つことができる。しかも不活性ガス供給流路か
ら第２の排気室を介して第１の排気室に不活性ガスを供
給しているので、第１の排気室の排気ガスは不活性ガス
により排気流路側へ押出され、第１の排気室には不活性
ガスが充満しているので、たとえ焼結室の内圧が変動し
て焼結室に第１の排気室からガスが逆流しても、焼結室
に空気或は金属イオン等の不純物が侵入することは全く
ない。特に、排気室を第１の排気室と第２の排気室との
２段構造としているので、焼結室と大気との間の遮断は
完璧であり、焼結室に空気が侵入するのを確実に阻止で
きる。以上のことから、焼結室の内圧の変動に起因する
脱水ガラス化工程における脱水効果の変動や屈折率調整
用のドーパントの飛散量の変動がな（、非常に優れた特
性の光ファイバを得ることのできる光フアイバ母材を安
定して製造できる。(Effects of the Invention) As explained above, according to the present invention, the internal pressure of the sintering chamber is detected by the pressure detector, and the control device controls the flow control valve accordingly, thereby supplying the gas to the second exhaust chamber. Since the flow rate of the inert gas is controlled, the internal pressure of the sintering chamber can be kept constant at all times. Moreover, since the inert gas is supplied from the inert gas supply channel to the first exhaust chamber via the second exhaust chamber, the exhaust gas in the first exhaust chamber is pushed out to the exhaust channel side by the inert gas. Since the first exhaust chamber is filled with inert gas, even if the internal pressure of the sintering chamber fluctuates and gas flows back into the sintering chamber from the first exhaust chamber, the first exhaust chamber is filled with inert gas. There is no intrusion of impurities such as air or metal ions. In particular, since the exhaust chamber has a two-stage structure consisting of a first exhaust chamber and a second exhaust chamber, the sintering chamber is completely isolated from the atmosphere, and air is prevented from entering the sintering chamber. It can definitely be stopped. From the above, it is possible to obtain an optical fiber with very excellent characteristics without fluctuations in the dehydration effect during the dehydration vitrification process or fluctuations in the amount of scattering dopant for adjusting the refractive index due to fluctuations in the internal pressure of the sintering chamber. It is possible to stably produce optical fiber base materials that can
第１図は本発明の一実施例における光フアイバ母材製造
装置の概略構成図、第２図は従来の光フアイバ母材製造
５Ａ置の概略構成図である。
１・・・炉心管、３・・・種棒、５・・・第１の排気筒
体、６・・・第２の排気筒体、９・・・第１の蓋体、１
０・・・第２の蓋体、１１・・・第３の蓋体、１２〜１
４・・・透孔、１５・・・焼結室、１６・・・第１の排
気室、１７・・・第２の排気室、１９・・・圧力検出器
、２ｏ・・・制御装置、２２・・・不活性ガス供給流路
、２３・・・流量調節弁、２７・・・排気流路、２８・
・・排気処理装置特許出願人 三菱電線工業株式会社
１ ＋ ）
代理人 弁理士 大食忠孝、−・７′。
、Ｌ、・、、、、；ｉ
小１ｒシ１
１５ ・・・玩粕工FIG. 1 is a schematic diagram of an optical fiber preform manufacturing apparatus according to an embodiment of the present invention, and FIG. 2 is a schematic diagram of a conventional optical fiber preform manufacturing apparatus 5A. DESCRIPTION OF SYMBOLS 1... Furnace core tube, 3... Seed rod, 5... First exhaust tube body, 6... Second exhaust tube body, 9... First lid body, 1
0...Second lid body, 11...Third lid body, 12-1
4... Through hole, 15... Sintering chamber, 16... First exhaust chamber, 17... Second exhaust chamber, 19... Pressure detector, 2o... Control device, 22... Inert gas supply flow path, 23... Flow rate adjustment valve, 27... Exhaust flow path, 28.
... Exhaust treatment device patent applicant: Mitsubishi Cable Industries, Ltd. 1 +) Agent: Patent attorney: Tadataka Oshiki, - 7'. ,L,・,,,,;i Elementary 1r shi1 15...Toy Kasuko
Claims (1)
１の排気室を形成する第１の排気筒体と、この第１の排
気筒体の上側に配置されて第２の排気室を形成する第２
の排気筒体と、種棒が貫通する透孔を有し且つ前記焼結
室と第１の排気室とを区画する第１の蓋体と、前記種棒
が貫通する透孔を有し且つ前記第１の排気室と第２の排
気室とを区画する第２の蓋体と、前記種棒が貫通する透
孔を有し且つ前記第２の排気室と外部とを区画する第３
の蓋体と、前記第２の排気室に不活性ガスを供給する不
活性ガス供給流路と、この不活性ガス供給流路に配置さ
れた流量調節弁と、前記焼結室の圧力を検出する圧力検
出器と、この圧力検出器からの信号により前記焼結室の
圧力に応じて前記流量調節弁を制御する制御装置と、前
記第１の排気室と排気処理装置とを連通させる排気流路
とを設け、前記焼結室の圧力が増加したときには前記第
２の排気室に供給する不活性ガスの量を減少させ、前記
焼結室の圧力が減少したときには前記第２の排気室に供
給する不活性ガスの量を増加させる構成としたことを特
徴とする光ファイバ母材製造装置。A first exhaust cylinder body is arranged above the furnace core tube forming the sintering chamber of the sintering furnace and forms a first exhaust chamber, and a second exhaust cylinder body is arranged above the first exhaust cylinder body. The second forming the exhaust chamber
an exhaust cylinder body, a first lid body having a through hole through which the seed rod passes and partitioning the sintering chamber and the first exhaust chamber, and a through hole through which the seed rod penetrates; a second lid that partitions the first exhaust chamber and the second exhaust chamber; and a third lid that has a through hole through which the seed rod passes and that partitions the second exhaust chamber from the outside.
a lid body, an inert gas supply channel for supplying inert gas to the second exhaust chamber, a flow rate control valve disposed in the inert gas supply channel, and a pressure in the sintering chamber detected. a control device that controls the flow rate adjustment valve according to the pressure in the sintering chamber based on a signal from the pressure detector; and an exhaust flow that communicates the first exhaust chamber and the exhaust treatment device. a channel for reducing the amount of inert gas supplied to the second exhaust chamber when the pressure in the sintering chamber increases, and supplying the inert gas to the second exhaust chamber when the pressure in the sintering chamber decreases. 1. An optical fiber preform manufacturing apparatus characterized by being configured to increase the amount of inert gas supplied.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP30605886A JPS63159232A (en) | 1986-12-22 | 1986-12-22 | Production apparatus for optical fiber preform |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP30605886A JPS63159232A (en) | 1986-12-22 | 1986-12-22 | Production apparatus for optical fiber preform |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63159232A true JPS63159232A (en) | 1988-07-02 |
Family
ID=17952540
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP30605886A Pending JPS63159232A (en) | 1986-12-22 | 1986-12-22 | Production apparatus for optical fiber preform |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63159232A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0251436A (en) * | 1988-08-11 | 1990-02-21 | Fujikura Ltd | Dehydrating sintering furnace for mother material of optical glass |
| EP1717212A1 (en) * | 2005-04-29 | 2006-11-02 | The Boc Group, Inc. | Process for consolidating a glass optical fibre preform |
| CN104098255A (en) * | 2013-04-10 | 2014-10-15 | 信越化学工业株式会社 | Sintering apparatus |
| EP2805928A1 (en) * | 2013-05-21 | 2014-11-26 | Shin-Etsu Chemical Co., Ltd. | Method and apparatus for sintering a glass preform for an optical fiber |
-
1986
- 1986-12-22 JP JP30605886A patent/JPS63159232A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0251436A (en) * | 1988-08-11 | 1990-02-21 | Fujikura Ltd | Dehydrating sintering furnace for mother material of optical glass |
| EP1717212A1 (en) * | 2005-04-29 | 2006-11-02 | The Boc Group, Inc. | Process for consolidating a glass optical fibre preform |
| CN104098255A (en) * | 2013-04-10 | 2014-10-15 | 信越化学工业株式会社 | Sintering apparatus |
| EP2789590A1 (en) * | 2013-04-10 | 2014-10-15 | Shin-Etsu Chemical Co., Ltd. | Sintering apparatus |
| JP2014201513A (en) * | 2013-04-10 | 2014-10-27 | 信越化学工業株式会社 | Sintering apparatus |
| EP2805928A1 (en) * | 2013-05-21 | 2014-11-26 | Shin-Etsu Chemical Co., Ltd. | Method and apparatus for sintering a glass preform for an optical fiber |
| US9422185B2 (en) | 2013-05-21 | 2016-08-23 | Shin-Etsu Chemical Co., Ltd. | Apparatus for sintering a glass preform for an optical fiber and sintering method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2002531366A (en) | Method for producing tubes made of vitreous material, in particular quartz glass | |
| EP1440946B1 (en) | Method and apparatus for processing a preform for an optical fibre using a burner | |
| US4440556A (en) | Optical fiber drawing using plasma torch | |
| US4813989A (en) | Apparatus for fabricating optical fiber preform | |
| EP0231022B1 (en) | Apparatus for the production of porous preform of optical fiber | |
| US4428762A (en) | Vapor-phase axial deposition system | |
| EP0200215A1 (en) | Raw material supplying device and process for using this device | |
| JPS63159232A (en) | Production apparatus for optical fiber preform | |
| CA1290149C (en) | Heat treating apparatus and method of operating heat treating apparatus | |
| JP4165879B2 (en) | Method and apparatus for manufacturing glass optical fiber preform by vapor phase growth method | |
| JPS63159231A (en) | Production apparatus for optical fiber preform | |
| JPH0340932A (en) | Accumulation device for glass fine particle | |
| JPS61197439A (en) | Production of porous glass rod and devices therefor | |
| JP2005075682A (en) | Method of manufacturing porous glass preform | |
| JPH02212325A (en) | Furnace for dehydrating and sintering optical fiber preform | |
| EP0105926B1 (en) | Vapor-phase axial deposition system | |
| JP3788301B2 (en) | Gas shunting device, porous glass base material manufacturing device, and porous glass base material manufacturing method | |
| JPS5761641A (en) | Manufacturing of optical fiber preform | |
| JPS62162636A (en) | Sintering apparatus for porous preform for optical fiber | |
| JPS63285133A (en) | Furnace for drawing optical fiber | |
| JPS6126531A (en) | Production of base material for optical fiber | |
| JPS6044258B2 (en) | synthesis torch | |
| JPH06316422A (en) | Producing device for glass preform | |
| JPS60155538A (en) | Production of porous preform for optical use | |
| JPH02283632A (en) | Deposition apparatus for fine glass particle |