JPS63159231A - Production apparatus for optical fiber preform - Google Patents
Production apparatus for optical fiber preformInfo
- Publication number
- JPS63159231A JPS63159231A JP30605786A JP30605786A JPS63159231A JP S63159231 A JPS63159231 A JP S63159231A JP 30605786 A JP30605786 A JP 30605786A JP 30605786 A JP30605786 A JP 30605786A JP S63159231 A JPS63159231 A JP S63159231A
- Authority
- JP
- Japan
- Prior art keywords
- chamber
- exhaust
- sintering
- inert gas
- 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 10
- 238000005245 sintering Methods 0.000 claims abstract description 62
- 239000011261 inert gas Substances 0.000 claims abstract description 43
- 238000000638 solvent extraction Methods 0.000 claims description 3
- 230000003247 decreasing effect Effects 0.000 claims 1
- 239000012535 impurity Substances 0.000 abstract description 7
- 239000007789 gas Substances 0.000 description 45
- 239000000463 material Substances 0.000 description 11
- 230000018044 dehydration Effects 0.000 description 8
- 238000006297 dehydration reaction Methods 0.000 description 8
- 239000004071 soot Substances 0.000 description 8
- 238000000034 method Methods 0.000 description 7
- 238000004017 vitrification Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 4
- 229910021645 metal ion Inorganic materials 0.000 description 4
- 239000012024 dehydrating agents Substances 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 239000002019 doping agent Substances 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- YBMRDBCBODYGJE-UHFFFAOYSA-N germanium dioxide Chemical compound O=[Ge]=O YBMRDBCBODYGJE-UHFFFAOYSA-N 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
- 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
- 230000006378 damage Effects 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- 239000005373 porous glass Substances 0.000 description 1
- 230000010349 pulsation 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
- C03B37/0146—Furnaces therefor, e.g. muffle tubes, furnace linings
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Physics & Mathematics (AREA)
- General Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Thermal Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Manufacture, Treatment Of Glass Fibers (AREA)
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アイバ母材製造装置に関するも
のである。DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an optical fiber preform manufacturing apparatus for obtaining an optical fiber preform by dehydrating and vitrifying an optical fiber preform soot.
(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、5i02に屈
折率調整用のドーパントとしてのGeO□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する方法がある。(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 GeO□ as a dopant for adjusting the refractive index is distributed in 5i02,
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ァイバf!1′材を製造するに
は、従来第2図に示すように、光フアイバ母材スート5
0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012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5
3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5
5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。By such a method, optical fiber f! 1' material, conventionally, as shown in FIG.
A seed rod 51 made of quartz glass with 0 formed at the tip is inserted into the core tube 52 of the sintering furnace from the tip side, and He gas and 012 gas as a dehydrating agent are supplied from the lower end of the core tube 52. The rod 51 is rotated and gradually lowered, and the heater 5
3. By heating the optical fiber base material soot 50
The optical fiber preform 54 was obtained by dehydration and vitrification. The He and C12 gases in the reactor core tube 52 are then transferred to the exhaust cylinder 5.
5 was suctioned by an exhaust treatment device through an exhaust flow path 56 connected to the exhaust flow path 56. Note that the inside of the furnace core tube 52 and the exhaust cylinder body 55
The inside of the exhaust cylinder body 55 is separated from the atmosphere by a lid body 57, and the inside of the exhaust cylinder body 55 and the atmosphere are divided by a lid body 58. The lid bodies 57 and 58 have a through hole through which the seed rod 51 passes. It is perforated.
また排気流路56には手動パルプ59が設置されている
。Further, a manual pulp 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答により変動する。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 non-uniform 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1ft52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 core 1 ft 52 changes in this way, the dehydration effect will change 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. .
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の内圧と類シールガ
ス圧との差が±201111820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. If the furnace is operated in a state where the difference between the internal pressure of the furnace core tube 52 and the similar seal gas pressure is ±201111820 or more, the furnace core tube 52 will be deformed during the long dehydration and vitrification process, leading to destruction. 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 57, causing the exhaust to flow back into the core tube 52, causing air and gas to flow from the outside. There is a risk of impurities such as metal ions entering.
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の内圧を一定にプ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 kept 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連
結されて排気室を形成する排気筒体と、種棒が貫通ずる
透孔を有し且つ前記焼結室と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排気室
と外部とを区画する第2の蓋体と、前記排気室に不活性
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R調節弁をl1l
tllする制御装置と、前記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
したときには前記排気室に供給する不活性ガスの損を減
少させ、前記焼結室の圧力が減少したときには前記排気
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 has an exhaust chamber connected to the upper side of a core tube forming a sintering chamber of a sintering furnace. an exhaust cylinder body to be formed; a first lid body having a through hole through which the seed rod passes and partitioning the sintering chamber and the exhaust chamber; and a first lid body having a through hole through which the seed rod passes through and the exhaust chamber; a second lid body that partitions the chamber and the outside; an inert gas supply channel that supplies inert gas to the exhaust chamber; a flow rate control valve disposed in the inert gas supply channel; A pressure detector detects the pressure in the sintering chamber, and a signal from the pressure detector controls the flow R control valve according to the pressure in the sintering chamber.
tll and an exhaust flow path that communicates the exhaust chamber with an exhaust treatment device to reduce loss of inert gas supplied to the exhaust chamber when the pressure in the sintering chamber increases; The structure is such that when the pressure in the sintering chamber decreases, the amount of inert gas supplied to the exhaust chamber is increased.
(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in、i1節弁を制御して、焼結室の圧力が増加し
たときには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排気室に供給する不
活性ガスの社を増加させて、炉心管の内圧を一定に保つ
。(Function) The gas supplied to the sintering chamber reaches the 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 in and i1 control valves according to the signal from the pressure detector, so that when the pressure in the sintering chamber increases, supply is supplied to the exhaust chamber. When the pressure in the sintering chamber decreases, the amount of inert gas supplied to the 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〜第 図に基づいて説
明する。(Example) Hereinafter, an example of the present invention will be described based on FIGS.
第1図は本発明の一実施例における光ファイバBl材製
造V41の概略構成図で、1は焼結炉の炉心管であり、
この炉心11には、下端からト1eガスと脱水剤として
のC12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排気筒体5が連結されている
。FIG. 1 is a schematic configuration diagram of optical fiber Bl material production V41 in one embodiment of the present invention, 1 is a core tube of a sintering furnace,
The reactor core 11 is supplied with the To 1e gas and the C12 gas as a dehydrating agent from the lower end, and the tip of the seed rod 3 having the optical fiber preform soot 2 formed at its tip is inserted from the upper side. 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 an exhaust cylinder body 5 made of, for example, quartz glass is connected to the upper side.
この排気筒体5は管状のガス排出部6及び不活性ガス導
入部7を側面に有しており、下端7ランジ部には第1の
蓋体8が、上端フランジ部には第2の蓋体9がそれぞれ
載置されている。これら第1の蓋体8及び第2の蓋体9
は、周方向2つ割りの円板状で、中心部に前記種棒3が
貫通する透孔10或は透孔11を有している。前記第1
の蓋体8は前記炉心管1により形成される焼結室12と
前記排気筒体5により形成される排気室13とを区画し
ており、前記第2の蓋体9は前記排気室13と大気とを
区画している。前記焼結室12は、一端が閉塞された管
路14に連通しており、この管路14には指示計器付の
圧力検出器15が設置されている。この圧力検出器15
は制御装置16に接続されており、圧力検出器15と制
御装@16との接続点には設定器17が接続されている
。前記不活性ガス専大部7は不活性ガス供給流路18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18には前記制御装置16により制?
IBされる流量:J4W1弁19が設置されている。前
記ガス排出部6は先端部が排気箱20に貴人しており、
この排気箱20は不活性ガス流入部21と排気ガス流出
部22とを有している。This exhaust cylinder body 5 has a tubular gas discharge part 6 and an inert gas introduction part 7 on the side surface, a first lid body 8 is provided on the flange part of the lower end 7, and a second lid part is provided on the upper end flange part. A body 9 is placed respectively. These first lid body 8 and second lid body 9
is in the shape of a disc divided into two in the circumferential direction, and has a through hole 10 or 11 in the center through which the seed rod 3 passes. Said first
The lid 8 separates a sintering chamber 12 formed by the furnace core tube 1 and an exhaust chamber 13 formed by the exhaust cylinder 5, and the second lid 9 separates the exhaust chamber 13 from the exhaust chamber 13. It is separated from the atmosphere. The sintering chamber 12 communicates with a conduit 14 whose one end is closed, and a pressure detector 15 with an indicator is installed in this conduit 14. This pressure detector 15
is connected to the control device 16, and a setting device 17 is connected to the connection point between the pressure detector 15 and the control device @16. The inert gas supply section 7 is connected to an inert gas supply device (not shown) via an inert gas supply channel 18, and the inert gas supply channel 18 is controlled by the control device 16.
IB flow rate: J4W1 valve 19 is installed. The tip of the gas exhaust section 6 is connected to the exhaust box 20,
This exhaust box 20 has an inert gas inlet 21 and an exhaust gas outlet 22.
前記不活性ガス流入部21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22は排気流路23を介して排気処理Q置24に接続
されている。なお25は光フフイバ母材スート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 21 is connected to the inert gas supply device via a pipe (not shown), and the exhaust gas outlet 22 is connected to the exhaust treatment Q unit 24 via an exhaust flow path 23. ing. Note that 25 is an optical fiber base material made by dehydrating and vitrifying the optical fiber base material soot 2.
次に作用を説明する。まず第1の蓋体8及び第2の蓋体
9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。そして光フフイバ母材スート2部分が
焼結室12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8を排気筒体5の下端フランジ部に載置し
、第2の蓋体9を排気筒体5の上端7ランジ部に載iす
る。この状態で焼結室12にHeガス及び脱水剤として
の012ガスを供給し、ヒータ4で焼結室12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、光フアイバ母材25にな
る。このとき、焼結室12に供給されたガスは、種棒3
と第1の蓋体8との間隙から排気室13に流入し、ガス
排出部6を通って排気される。そして、焼結室12の内
圧が圧力検出器15により検出され、圧力検出器15の
信号が制御装E16に供給されて、それにより制御装置
16は流過調節弁19を制御する。即ち、焼結室12の
内圧が設定器17で設定した設定値よりも大きい場合、
制御装置16は流量調節弁19を絞って排気室13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
量を減少させ、逆に焼結室12の内圧が設定器17で設
定した設定値よりも小さい場合、制御装置16は流量調
節弁19を更に開放して排気室13への不活性ガスの流
入量を増加させる。これにより排気室13の内圧が制御
され、焼結室12から種棒3と第1の蓋体8との間隙を
通って排気室13に流入する排気ガスの流はが変化して
、焼結室12の内圧が一定に保たれる。一方、ガス排出
部6から排気箱20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21から
供給されるH G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22から吸引排
気される。Next, the effect will be explained. First, the first lid 8 and the second lid 9 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 the 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 12, the first lid 8 is placed on the lower end flange of the exhaust cylinder 5, and the second Place the lid 9 on the flange portion of the upper end 7 of the exhaust cylinder 5. In this state, He gas and 012 gas as a dehydrating agent are supplied to the sintering chamber 12, the sintering chamber 12 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 25. At this time, the gas supplied to the sintering chamber 12 is
The gas flows into the exhaust chamber 13 through the gap between the gas and the first lid 8 and is exhausted through the gas exhaust section 6. Then, the internal pressure of the sintering chamber 12 is detected by the pressure detector 15, and a signal from the pressure detector 15 is supplied to the control device E16, whereby the control device 16 controls the flow control valve 19. That is, when the internal pressure of the sintering chamber 12 is higher than the set value set by the setting device 17,
The control device 16 throttles the flow rate control valve 19 to reduce the amount of inert gas such as He, Ar, or a mixture of these flowing into the exhaust chamber 13, and conversely, the internal pressure of the sintering chamber 12 is controlled by the setting device 17. If it is smaller than the set value, the control device 16 further opens the flow control valve 19 to increase the amount of inert gas flowing into the exhaust chamber 13. As a result, the internal pressure of the exhaust chamber 13 is controlled, and the flow of exhaust gas flowing from the sintering chamber 12 into the exhaust chamber 13 through the gap between the seed rod 3 and the first lid 8 changes, and the sintering The internal pressure of chamber 12 is kept constant. On the other hand, the mixed exhaust gas of exhaust gas and inert gas that has flowed into the inside of the exhaust box 20 from the gas discharge section 6 is mixed with H, G, Ar, etc., or a mixture thereof supplied from the inert gas inflow section 21. The exhaust gas is sucked and exhausted from the exhaust gas outlet 22 together with an inert gas consisting of gas.
このように、焼結室12の内圧を検出してそれに応じて
排気室13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12の内圧を常に一定に保つことができる
。しかも排気室13に不活性ガスを供給しているので、
排気室13の排気ガスは不活性ガスによりガス排出部6
から排気箱20側へ押出され、排気室13には不活性ガ
スが充満しているので、たとえ焼結室12の内圧が変動
して焼結室12に排気室13からガスが逆流しても、焼
結室12に空気或は金属イオン等の不純物が侵入するこ
とばはとんとない。しかも本実施例では排気箱20を設
け、この内部にも不活性ガス流入部21から不活性ガス
を供給しているので、排気室13及び排気箱20の内部
には不活性ガスが充満しており、焼結室12への不純物
の侵入をより確実に防止できる。この排気箱20は、排
気流路23を構成する管路内の金属イオン等の不純物が
焼結室12に侵入するのを防止するのに特に有効である
。 ″
上記実施例の装置を用いて、焼結室12にHe及びC1
2ガスを毎分10リツトル供給し、排気113にHeガ
スを毎分10リツトル供給し、不活性ガス流入部21を
閉塞して、焼結室12の内圧の±O−2s H20の変
化に対して排気室13に供給するHeガスの供給量を毎
分±5リットルの割合で変化させるように制御したとこ
ろ、焼結室12の内圧は、−1,2a*H20±0.2
sw H20の範囲で完全に安定した。In this way, since the internal pressure of the sintering chamber 12 is detected and the flow rate of the inert gas supplied to the exhaust chamber 13 is controlled accordingly, the internal pressure of the sintering chamber 12 can always be kept constant. Moreover, since inert gas is supplied to the exhaust chamber 13,
The exhaust gas in the exhaust chamber 13 is transferred to the gas exhaust section 6 by inert gas.
Since the exhaust chamber 13 is filled with inert gas, even if the internal pressure of the sintering chamber 12 fluctuates and the gas flows back into the sintering chamber 12 from the exhaust chamber 13. It is extremely likely that impurities such as air or metal ions will enter the sintering chamber 12. Moreover, in this embodiment, the exhaust box 20 is provided, and inert gas is supplied from the inert gas inlet 21 to the inside thereof, so that the inside of the exhaust chamber 13 and the exhaust box 20 are filled with inert gas. Therefore, it is possible to more reliably prevent impurities from entering the sintering chamber 12. This exhaust box 20 is particularly effective in preventing impurities such as metal ions in the pipe constituting the exhaust flow path 23 from entering the sintering chamber 12. ″ Using the apparatus of the above embodiment, He and C1 are added to the sintering chamber 12.
2 gas is supplied at 10 liters per minute, He gas is supplied at 10 liters per minute to the exhaust gas 113, and the inert gas inlet 21 is closed. When the amount of He gas supplied to the exhaust chamber 13 was controlled to change at a rate of ±5 liters per minute, the internal pressure of the sintering chamber 12 was -1.2a*H20±0.2.
Completely stable in the sw H20 range.
また、焼結室12にHe及びC1゜ガスを毎分10リツ
トル供給し、排気室13に)leガスを毎分20リツト
ル供給し、不活性ガス流入部21を閉塞して、焼結室1
2の内圧の±0.2txtx H20の変化に対して排
気室13に供給するHeガスの供給量を毎分±5リット
ルの割合で変化させるように制御したところ、焼結室1
2の内圧は、+0.4as+Ho±0.2ms H20
の範囲で完全に安定した。Furthermore, 10 liters of He and C1° gas are supplied per minute to the sintering chamber 12, 20 liters of Le gas is supplied to the exhaust chamber 13, and the inert gas inlet 21 is closed.
When controlling the supply amount of He gas to be supplied to the exhaust chamber 13 at a rate of ±5 liters per minute in response to a change in the internal pressure of sintering chamber 1 by ±0.2txtx H20,
The internal pressure of 2 is +0.4as+Ho±0.2ms H20
completely stable in the range of .
また、焼結室12にHe及びC1□ガスを毎分10リツ
トル供給し、排気室13にHeガスを毎分20リツトル
供給し、不活性ガス流入部21から排気箱20内に不活
性ガスを毎分10リツトル供給して、焼結室12の内圧
の±0.2a*H20の変化に対して排気室13に供給
する1−18ガスの供給量を毎分±5リットルの割合で
変化させるように制御したところ、焼結室12の内圧は
、+1.5smHo±0.2a* H20の範囲で完全
に安定した。In addition, 10 liters of He and C1□ gas are supplied per minute to the sintering chamber 12, 20 liters of He gas is supplied per minute to the exhaust chamber 13, and inert gas is supplied from the inert gas inlet 21 into the exhaust box 20. Supplying 10 liters per minute, the supply amount of 1-18 gas supplied to the exhaust chamber 13 is changed at a rate of ±5 liters per minute in response to a ±0.2a*H20 change in the internal pressure of the sintering chamber 12. When controlled as follows, the internal pressure of the sintering chamber 12 was completely stabilized within the range of +1.5smHo±0.2a*H20.
(別の実施例)
上記実施例においては、設定器17により焼結室12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
2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17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 12 can be set using the setting device 17.
If the reference value of the internal pressure 2 is always constant and does not need to be changed, the setting device 17 may not be provided.
また上記実施例においては、排気箱20を設けて焼結室
12への不純物の侵入を確実に防止できるようにしてい
るが、この排気1i20は必ずしも設ける必要はない。Further, in the above embodiment, the exhaust box 20 is provided to reliably prevent impurities from entering the sintering chamber 12, but the exhaust 1i20 is not necessarily required.
(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を介して
排気室に不活性ガスを供給しているので、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、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
ほとんどない。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く、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 inert gas is supplied to the exhaust chamber by controlling the flow control valve by the control device accordingly. Since the gas flow rate is controlled, the internal pressure in the sintering chamber can be kept constant at all times. Moreover, since the inert gas is supplied to the exhaust chamber through the inert gas supply channel, the exhaust gas in the exhaust chamber is pushed toward the exhaust channel by the inert gas, and the exhaust chamber is filled with inert gas. Therefore, even if the internal pressure of the sintering chamber fluctuates and gas flows back into the sintering chamber from the exhaust chamber, impurities such as air or metal ions will hardly enter the sintering chamber. From the above, it is possible to obtain an optical fiber with extremely excellent characteristics without fluctuations in the dehydration effect during the dehydration vitrification process or fluctuations in the amount of scattering dopants for adjusting the refractive index caused by fluctuations in the internal pressure of the sintering chamber. It is possible to stably produce optical fiber base materials that can achieve
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
装置の概略構成図である。
1・・・炉心管、3・・・種棒、5・・・排気筒体、8
・・・第1の蓋体、9・・・第2の蓋体、10.11・
・・透孔、12・・・焼結室、13・・・排気室、15
・・・圧力検出器、16・・・制御装置、18・・・不
活性ガス供給流路、19・・・流量調節弁、23・・・
排気流路、24・・・排気処理装置
特許出願人 三菱電線工業株式会社
lIJ・ ;1
代理人 弁理士 大食忠孝 シ、テ、、11o・−・ノ
2゛
第1図
牛
e
7・・・炉心Vt C/、 13
・・・祷気!3・・・種棒 7
5・・・圧力検出器5・−nF気+tr+s
76・−8F1111ii18・・・第7
の蓋体 78・・・不活性ゲ
ス4A船弓1路9・・・第2の量体
79・・・流量11節弁10.11・・・通孔
23・・・排気i路72・・焼!4”l
24・・・↑奔気処理装置lzFIG. 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. 1... Furnace core tube, 3... Seed rod, 5... Exhaust tube body, 8
...first lid body, 9...second lid body, 10.11.
...Through hole, 12...Sintering chamber, 13...Exhaust chamber, 15
...Pressure detector, 16...Control device, 18...Inert gas supply channel, 19...Flow rate control valve, 23...
Exhaust flow path, 24...Exhaust treatment device Patent applicant: Mitsubishi Cable Industries, Ltd. lIJ; 1 Agent: Patent attorney Tadaka Oshiki Shi, Te,, 11o...ノ2゛Figure 1 Cow e 7...・Core Vt C/, 13
...Prayer! 3... Seed stick 7
5... Pressure detector 5 -nF air+tr+s
76・-8F1111ii18...7th
Lid body 78...Inert Guess 4A bow 1st route 9...Second body
79...Flow rate 11 section valve 10.11...Through hole
23...Exhaust i-way 72...Yaki! 4”l
24...↑Air processing device lz
Claims (1)
気室を形成する排気筒体と、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排気室と外部とを
区画する第2の蓋体と、前記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。an exhaust cylinder connected to the upper side of a furnace core tube forming a sintering chamber of a sintering furnace to form an exhaust chamber; and a through hole through which a seed rod passes, and partitioning the sintering chamber and the exhaust chamber. a first lid body, a second lid body having a through hole through which the seed rod passes and partitioning the exhaust chamber from the outside; and an inert gas supply flow that supplies inert gas to the exhaust chamber. a flow rate 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 pressure detector according to the pressure in the sintering chamber. A control device that controls the flow rate adjustment valve and an exhaust flow path that communicates the exhaust chamber and the exhaust treatment device are provided, and when the pressure in the sintering chamber increases, the amount of inert gas to be supplied to the exhaust chamber. An optical fiber preform manufacturing apparatus characterized in that the amount of inert gas supplied to the exhaust chamber is increased when the pressure in the sintering chamber is decreased.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP30605786A JPS63159231A (en) | 1986-12-22 | 1986-12-22 | Production apparatus for optical fiber preform |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP30605786A JPS63159231A (en) | 1986-12-22 | 1986-12-22 | Production apparatus for optical fiber preform |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS63159231A true JPS63159231A (en) | 1988-07-02 |
Family
ID=17952527
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP30605786A Pending JPS63159231A (en) | 1986-12-22 | 1986-12-22 | Production apparatus for optical fiber preform |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS63159231A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2000264650A (en) * | 1999-03-17 | 2000-09-26 | Shinetsu Quartz Prod Co Ltd | Production of optical quartz glass for excimer laser and vertical type heating furnace |
-
1986
- 1986-12-22 JP JP30605786A patent/JPS63159231A/en active Pending
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2000264650A (en) * | 1999-03-17 | 2000-09-26 | Shinetsu Quartz Prod Co Ltd | Production of optical quartz glass for excimer laser and vertical type heating furnace |
JP4493060B2 (en) * | 1999-03-17 | 2010-06-30 | 信越石英株式会社 | Manufacturing method of optical quartz glass for excimer laser |
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