JPH06127964A - Dehydration sintering furnace for optical fiber preform - Google Patents
Dehydration sintering furnace for optical fiber preformInfo
- Publication number
- JPH06127964A JPH06127964A JP27981292A JP27981292A JPH06127964A JP H06127964 A JPH06127964 A JP H06127964A JP 27981292 A JP27981292 A JP 27981292A JP 27981292 A JP27981292 A JP 27981292A JP H06127964 A JPH06127964 A JP H06127964A
- Authority
- JP
- Japan
- Prior art keywords
- core tube
- furnace
- pressure
- optical fiber
- furnace core
- 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
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
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)
- Glass Melting And Manufacturing (AREA)
- Manufacture, Treatment Of Glass Fibers (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、ガラス微粒子を堆積し
て作られた光ファイバ母材を脱水及び透明ガラス化する
光ファイバ母材の脱水焼結炉に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber preform dehydration sintering furnace for dehydrating an optical fiber preform made by depositing glass fine particles and converting it into a transparent glass.
【０００２】[0002]
【従来の技術】図３は、従来のこの種の光ファイバ母材
の脱水焼結炉を示したものである。該光ファイバ母材の
脱水焼結炉は、脱水焼結すべき光ファイバ母材１を収容
する石英製の炉心管２と、該炉心管２の外で光ファイバ
母材１を加熱するヒータ３と、該炉心管２の外周で断熱
材４を介してヒータ３を収容している炉体５とを備えて
いる。2. Description of the Related Art FIG. 3 shows a conventional dehydration sintering furnace for optical fiber preforms of this type. The dehydration / sintering furnace for the optical fiber preform comprises a quartz core tube 2 for containing the optical fiber preform 1 to be dehydrated and sintered, and a heater 3 for heating the optical fiber preform 1 outside the core tube 2. And a furnace body 5 accommodating the heater 3 on the outer periphery of the core tube 2 with a heat insulating material 4 interposed therebetween.
【０００３】炉心管２内には、その下部のガス供給口６
からヘリウムガスの如き不活性ガスと塩化ガスの如き脱
水ガスとが供給されるようになっている。炉心管２の上
部には、ガス排気口７が設けられている。Inside the core tube 2, a gas supply port 6 at the bottom thereof is provided.
An inert gas such as helium gas and a dehydrating gas such as chloride gas are supplied from the above. A gas exhaust port 7 is provided above the core tube 2.
【０００４】炉体５内には、ヒータ３及び断熱材４が酸
化による劣化を起こさないように、下部のガス供給口８
からアルゴンガスの如き不活性ガスが供給されるように
なっている。炉心管２の上部には、ガス排気口９が設け
られている。In the furnace body 5, the lower gas supply port 8 is provided so that the heater 3 and the heat insulating material 4 do not deteriorate due to oxidation.
An inert gas such as argon gas is supplied from the. A gas exhaust port 9 is provided at the top of the core tube 2.
【０００５】更に、該光ファイバ母材の脱水焼結炉は、
炉心管２内と炉体５内とのガス圧力を比較して炉心管２
内のガス圧力が所定の圧力となるように炉心管２内のガ
ス圧力を制御するガス圧制御機構１０が設けられてい
る。該ガス圧制御機構１０は、炉心管２内と炉体５内と
のガス圧力を比較する差圧計１１と、該差圧計１１で計
測した差圧が所定以上になったとき炉心管２のガス排気
口７から排出されるガスの量を制御する電動弁１２とで
構成されている。Further, the dehydration sintering furnace for the optical fiber preform is
By comparing the gas pressures in the core tube 2 and the furnace body 5, the core tube 2
A gas pressure control mechanism 10 is provided for controlling the gas pressure in the core tube 2 so that the gas pressure in the furnace becomes a predetermined pressure. The gas pressure control mechanism 10 includes a differential pressure gauge 11 for comparing gas pressures in the core tube 2 and the furnace body 5, and a gas in the core tube 2 when the differential pressure measured by the differential pressure gauge 11 exceeds a predetermined value. The motor-operated valve 12 controls the amount of gas discharged from the exhaust port 7.
【０００６】このような光ファイバ母材の脱水焼結炉で
は、炉心管２はヒータ３による加熱のため非常に高温に
なって柔らかくなる。このとき、炉心管２内と炉体５内
との圧力差が大きくなれば、炉心管２は変形し、時には
つぶれたり、穴があいたりする。それを防止するために
は、炉心管２内の圧力を炉体５内の圧力より一定圧力だ
け高くなるように制御する必要がある。そこで差圧計１
１により炉心管２内と炉体５内との差圧を測定し、その
値により電動弁１２の開度を変化させ、炉心管２内と炉
体５内との差圧を制御する。In such a dehydration sintering furnace for optical fiber preforms, the furnace core tube 2 is heated to a very high temperature by the heater 3 and becomes soft. At this time, if the pressure difference between the inside of the furnace core tube 2 and the inside of the furnace body 5 becomes large, the furnace core tube 2 is deformed and sometimes collapses or has a hole. In order to prevent this, it is necessary to control the pressure in the core tube 2 to be higher than the pressure in the furnace body 5 by a certain pressure. So the differential pressure gauge 1
1, the differential pressure between the core tube 2 and the furnace body 5 is measured, and the opening degree of the motor-operated valve 12 is changed according to the value to control the differential pressure between the core tube 2 and the furnace body 5.
【０００７】[0007]
【発明が解決しようとする課題】しかしながら、このよ
うな従来の光ファイバ母材の脱水焼結炉では、炉心管２
内と炉体５内との差圧について、長周期の変動は制御で
きたが、短周期の変動は制御しきれない問題点があっ
た。調査の結果、炉心管２内のガスの膨張などが短周期
の炉心管２内の圧力変動を引き起こしていることがわか
った。However, in such a conventional dehydration sintering furnace for optical fiber preforms, the core tube 2 is used.
Regarding the pressure difference between the inside and the inside of the furnace body 5, long-term fluctuations could be controlled, but short-term fluctuations could not be controlled. As a result of the investigation, it was found that expansion of gas in the core tube 2 causes pressure fluctuations in the core tube 2 in a short cycle.
【０００８】この内圧変動により炉心管２が変形するこ
とが多く見られた。炉心管２が内側にへこんだ場合、該
炉心管２内に所定外径の光ファイバ母材１を入れると、
炉心管２に接触し、不良品になってしまう。また、炉心
管２が外側に膨らんだ場合、該炉心管２はヒータ３に接
触し、該炉心管２に穴があき、有害なガスが漏れること
になる。It was often found that the core tube 2 was deformed by the fluctuation of the internal pressure. When the core tube 2 is dented inward, if the optical fiber preform 1 having a predetermined outer diameter is put in the core tube 2,
It contacts the core tube 2 and becomes a defective product. Further, when the core tube 2 bulges outward, the core tube 2 comes into contact with the heater 3, and a hole is formed in the core tube 2, and harmful gas leaks.
【０００９】本発明の目的は、炉心管内の短周期的な圧
力変動を吸収できる光ファイバ母材の脱水焼結炉を提供
することにある。An object of the present invention is to provide a dehydration / sintering furnace for optical fiber preforms capable of absorbing short-term pressure fluctuations in the core tube.
【００１０】[0010]
【課題を解決するための手段】上記の目的を達成する本
発明の構成を説明すると、本発明は脱水焼結すべき光フ
ァイバ母材を収容する炉心管と、前記炉心管の外で前記
光ファイバ母材を加熱するヒータと、前記炉心管の外周
で前記ヒータを収容している炉体とを備え、前記炉心管
内と前記炉体内とに不活性ガスを供給し、前記炉心管内
と前記炉体内とのガス圧力を比較して前記炉心管内のガ
ス圧力が所定の圧力となるように前記炉心管のガス圧力
を制御するガス圧制御機構を備えた光ファイバ母材の脱
水焼結炉において、前記炉心管にはその内部圧力の変動
を吸収する圧力変動吸収容器が接続されていることを特
徴とする。The structure of the present invention that achieves the above object will be described. The present invention is directed to a core tube containing an optical fiber preform to be dehydrated and sintered, and the optical tube outside the core tube. A heater for heating the fiber preform and a furnace body accommodating the heater on the outer periphery of the furnace core tube are provided, and an inert gas is supplied into the furnace core tube and the furnace body, and the furnace core tube and the furnace In the dehydration sintering furnace of the optical fiber preform provided with a gas pressure control mechanism for controlling the gas pressure of the core tube so that the gas pressure in the core tube becomes a predetermined pressure by comparing the gas pressure with the body, A pressure fluctuation absorbing container that absorbs fluctuations in the internal pressure is connected to the core tube.
【００１１】[0011]
【作用】このように炉心管に圧力変動吸収容器を接続し
ておくと、炉心管内の短周期的な圧力変動を吸収するこ
とができる。When the pressure fluctuation absorbing container is connected to the core tube in this manner, short-term pressure fluctuations in the core tube can be absorbed.
【００１２】[0012]
【実施例】図１は、本発明に係る光ファイバ母材の脱水
焼結炉の一実施例を示したものである。なお、前述した
図３と対応する部分には、同一符号を付けて示してい
る。本実施例の光ファイバ母材の脱水焼結炉では、炉心
管２内の内部圧力の変動を吸収する圧力変動吸収容器１
３が該炉心管２のガス排気口７に接続されている。本実
施例では、この圧力変動吸収容器１３はフッ素系樹脂の
シートで形成されている。フッ素系樹脂は、耐薬品性，
耐候性に優れている。また、シートで作ると、炉心管２
内と炉体５内との±数mmＨ2 Ｏ程度の微妙な差圧を吸収
し易い。FIG. 1 shows an embodiment of a dehydration sintering furnace for optical fiber preforms according to the present invention. The parts corresponding to those in FIG. 3 described above are designated by the same reference numerals. In the dehydration sintering furnace for the optical fiber preform of this embodiment, the pressure fluctuation absorbing container 1 that absorbs fluctuations in the internal pressure in the furnace core tube 2 is used.
3 is connected to the gas exhaust port 7 of the core tube 2. In this embodiment, the pressure fluctuation absorbing container 13 is made of a fluororesin sheet. Fluorine resin has chemical resistance,
Excellent weather resistance. Also, if it is made of sheet, the core tube 2
It is easy to absorb a delicate pressure difference of about ± several mmH 2 O between the inside and the inside of the furnace body 5.
【００１３】このような光ファイバ母材の脱水焼結炉で
は、炉心管２内と炉体５内との大きな差圧は電動弁１２
で調整し、炉体５内の微妙な圧力変動は圧力変動吸収容
器１３で吸収する。In such a dewatering and sintering furnace for optical fiber preforms, a large differential pressure between the core tube 2 and the furnace body 5 causes the motor-operated valve 12 to operate.
The pressure fluctuation absorbing container 13 absorbs subtle pressure fluctuations in the furnace body 5.
【００１４】図２は、本発明で用いる圧力変動吸収容器
１３の他の例を示したものである。本実施例では、圧力
変動吸収容器１３の上に微妙な圧力αで該圧力変動吸収
容器１３が膨らもうとする力と釣り合う重り１４が乗せ
られている。FIG. 2 shows another example of the pressure fluctuation absorbing container 13 used in the present invention. In the present embodiment, a weight 14 is placed on the pressure fluctuation absorbing container 13 to balance the force with which the pressure fluctuation absorbing container 13 tries to expand with a delicate pressure α.
【００１５】このようにすると、圧力変動吸収容器１３
内の圧力がαだけ上昇しようとすれば、重り１４が押し
上げられ、圧力変動吸収容器１３内の圧力がαだけ減少
しようとすれば、重り１４が下降され、圧力変動吸収容
器１３内の圧力が一定に保たれる。In this way, the pressure fluctuation absorbing container 13
If the pressure inside is increased by α, the weight 14 is pushed up, and if the pressure inside the pressure fluctuation absorbing container 13 is reduced by α, the weight 14 is lowered and the pressure inside the pressure fluctuation absorbing container 13 is increased. Is kept constant.
【００１６】[0016]
【発明の効果】以上説明したように本発明に係る光ファ
イバ母材の脱水焼結炉では、炉心管に圧力変動吸収容器
を接続したので、炉心管内の短周期的な圧力変動を吸収
することができる。このため炉心管が短周期的な圧力変
動で変形するのを防止することができる。As described above, in the dehydration / sintering furnace for optical fiber preforms according to the present invention, the pressure fluctuation absorbing container is connected to the core tube, so that short-term pressure fluctuations in the core tube are absorbed. You can Therefore, it is possible to prevent the core tube from being deformed by a short-term pressure fluctuation.
【図面の簡単な説明】[Brief description of drawings]
【図１】本発明に係る光ファイバ母材の脱水焼結炉の一
実施例の縦断面図である。FIG. 1 is a vertical sectional view of an embodiment of a dehydration sintering furnace for an optical fiber preform according to the present invention.
【図２】本発明に係る光ファイバ母材の脱水焼結炉で用
いる圧力変動吸収容器の他の例を示す縦断面図である。FIG. 2 is a vertical cross-sectional view showing another example of the pressure fluctuation absorbing container used in the dehydration sintering furnace for the optical fiber preform according to the present invention.
【図３】従来の光ファイバ母材の脱水焼結炉の一実施例
の縦断面図である。FIG. 3 is a longitudinal sectional view of an example of a conventional dehydration sintering furnace for optical fiber preforms.
１ 光ファイバ母材 ２ 炉心管 ３ ヒータ ４ 断熱材 ５ 炉体 ６ ガス供給口 ７ ガス排気口 ８ ガス供給口 ９ ガス排気口 １０ ガス圧制御機構 １１ 差圧計 １２ 電動弁 １３ 圧力変動吸収容器 １４ 重り 1 Optical Fiber Base Material 2 Core Tube 3 Heater 4 Heat Insulating Material 5 Furnace Body 6 Gas Supply Port 7 Gas Exhaust Port 8 Gas Supply Port 9 Gas Exhaust Port 10 Gas Pressure Control Mechanism 11 Differential Pressure Meter 12 Motorized Valve 13 Pressure Fluctuation Absorption Container 14 Weight
Claims (1)
る炉心管と、前記炉心管の外で前記光ファイバ母材を加
熱するヒータと、前記炉心管の外周で前記ヒータを収容
している炉体とを備え、前記炉心管内と前記炉体内とに
不活性ガスを供給し、前記炉心管内と前記炉体内とのガ
ス圧力を比較して前記炉心管内のガス圧力が所定の圧力
となるように前記炉心管のガス圧力を制御するガス圧制
御機構を備えた光ファイバ母材の脱水焼結炉において、 前記炉心管にはその内部圧力の変動を吸収する圧力変動
吸収容器が接続されていることを特徴とする光ファイバ
母材の脱水焼結炉。1. A furnace core tube containing an optical fiber base material to be dehydrated and sintered, a heater for heating the optical fiber base material outside the furnace core tube, and a heater provided on the outer periphery of the furnace core tube. A furnace body which is provided, supplies an inert gas into the furnace core tube and the furnace body, compares the gas pressures in the furnace core tube and the furnace body, and the gas pressure in the furnace core tube becomes a predetermined pressure. In the dehydration sintering furnace of the optical fiber preform having a gas pressure control mechanism for controlling the gas pressure of the furnace core tube, a pressure fluctuation absorbing container that absorbs fluctuations in its internal pressure is connected to the furnace core tube. A dewatering and sintering furnace for optical fiber preforms.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27981292A JPH06127964A (en) | 1992-10-19 | 1992-10-19 | Dehydration sintering furnace for optical fiber preform |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27981292A JPH06127964A (en) | 1992-10-19 | 1992-10-19 | Dehydration sintering furnace for optical fiber preform |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06127964A true JPH06127964A (en) | 1994-05-10 |
Family
ID=17616267
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP27981292A Pending JPH06127964A (en) | 1992-10-19 | 1992-10-19 | Dehydration sintering furnace for optical fiber preform |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06127964A (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2001016038A1 (en) * | 1999-08-26 | 2001-03-08 | The Furukawa Electric Co., Ltd. | Porous preform vitrifying device |
| US6543257B1 (en) * | 1999-05-28 | 2003-04-08 | The Furukawa Electric Co., Ltd. | Dehydration and sintering apparatus for porous optical fiber preform |
| US6845636B2 (en) | 2000-09-01 | 2005-01-25 | Sumitomo Electric Industries, Ltd. | Apparatus for dehydrating and consolidating an optical fiber preform and method of the same |
| JP2006056773A (en) * | 2004-07-22 | 2006-03-02 | Furukawa Electric Co Ltd:The | Method of dehydrating and sintering optical fiber porous preform and furnace of dehydrating and sintering the same |
| US7849714B2 (en) | 2003-12-08 | 2010-12-14 | Fujikura Ltd. | Dehydration-sintering furnace |
| US7866189B2 (en) | 2003-12-08 | 2011-01-11 | Fujikura Ltd. | Dehydration-sintering furnace, a manufacturing method of an optical fiber preform utilizing the furnace and an optical fiber preform manufactured by the method |
| WO2012002476A1 (en) * | 2010-06-30 | 2012-01-05 | 株式会社フジクラ | Reactor core tube inspection method and production method of parent metal for silica glass optical fibre |
| CN105669019A (en) * | 2016-04-19 | 2016-06-15 | 江苏亨通光导新材料有限公司 | Manufacturing device and manufacturing method of optical fiber preform rod |
| CN112645583A (en) * | 2021-01-13 | 2021-04-13 | 烽火通信科技股份有限公司 | System and method for automatically controlling pressure in optical fiber preform sintering furnace |
-
1992
- 1992-10-19 JP JP27981292A patent/JPH06127964A/en active Pending
Cited By (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6543257B1 (en) * | 1999-05-28 | 2003-04-08 | The Furukawa Electric Co., Ltd. | Dehydration and sintering apparatus for porous optical fiber preform |
| WO2001016038A1 (en) * | 1999-08-26 | 2001-03-08 | The Furukawa Electric Co., Ltd. | Porous preform vitrifying device |
| US6748766B2 (en) | 1999-08-26 | 2004-06-15 | The Furukawa Electric Co., Ltd. | Porous preform vitrification apparatus |
| US6845636B2 (en) | 2000-09-01 | 2005-01-25 | Sumitomo Electric Industries, Ltd. | Apparatus for dehydrating and consolidating an optical fiber preform and method of the same |
| US7849714B2 (en) | 2003-12-08 | 2010-12-14 | Fujikura Ltd. | Dehydration-sintering furnace |
| US7866189B2 (en) | 2003-12-08 | 2011-01-11 | Fujikura Ltd. | Dehydration-sintering furnace, a manufacturing method of an optical fiber preform utilizing the furnace and an optical fiber preform manufactured by the method |
| JP2006056773A (en) * | 2004-07-22 | 2006-03-02 | Furukawa Electric Co Ltd:The | Method of dehydrating and sintering optical fiber porous preform and furnace of dehydrating and sintering the same |
| CN102933511A (en) * | 2010-06-30 | 2013-02-13 | 株式会社藤仓 | Reactor core tube inspection method and production method of parent metal for silica glass optical fibre |
| WO2012002476A1 (en) * | 2010-06-30 | 2012-01-05 | 株式会社フジクラ | Reactor core tube inspection method and production method of parent metal for silica glass optical fibre |
| JPWO2012002476A1 (en) * | 2010-06-30 | 2013-08-29 | 株式会社フジクラ | Method for inspecting furnace core tube and method for producing base material for silica glass optical fiber |
| JP5542932B2 (en) * | 2010-06-30 | 2014-07-09 | 株式会社フジクラ | Method for inspecting core tube and method for producing base material for silica glass optical fiber |
| US8978421B2 (en) | 2010-06-30 | 2015-03-17 | Fujikura Ltd. | Muffle tube inspection method and manufacturing method of silica glass-based optical fiber preform |
| CN105669019A (en) * | 2016-04-19 | 2016-06-15 | 江苏亨通光导新材料有限公司 | Manufacturing device and manufacturing method of optical fiber preform rod |
| WO2017181649A1 (en) * | 2016-04-19 | 2017-10-26 | 江苏亨通光导新材料有限公司 | Manufacturing device and manufacturing method for optical fiber preform rod |
| CN105669019B (en) * | 2016-04-19 | 2018-08-07 | 江苏亨通光导新材料有限公司 | The manufacturing device and its manufacturing method of preform |
| CN112645583A (en) * | 2021-01-13 | 2021-04-13 | 烽火通信科技股份有限公司 | System and method for automatically controlling pressure in optical fiber preform sintering furnace |
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