JPH0781967A - Optical fiber drawing furnace - Google Patents
Optical fiber drawing furnaceInfo
- Publication number
- JPH0781967A JPH0781967A JP22565693A JP22565693A JPH0781967A JP H0781967 A JPH0781967 A JP H0781967A JP 22565693 A JP22565693 A JP 22565693A JP 22565693 A JP22565693 A JP 22565693A JP H0781967 A JPH0781967 A JP H0781967A
- Authority
- JP
- Japan
- Prior art keywords
- optical fiber
- insulating material
- heat
- heat insulating
- furnace
- 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
- C03B37/02—Manufacture of glass fibres or filaments by drawing or extruding, e.g. direct drawing of molten glass from nozzles; Cooling fins therefor
- C03B37/025—Manufacture of glass fibres or filaments by drawing or extruding, e.g. direct drawing of molten glass from nozzles; Cooling fins therefor from reheated softened tubes, rods, fibres or filaments, e.g. drawing fibres from preforms
- C03B37/029—Furnaces therefor
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B2205/00—Fibre drawing or extruding details
- C03B2205/60—Optical fibre draw furnaces
- C03B2205/70—Draw furnace insulation
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、光ファイバ母材から光
ファイバを線引きする際に用いられる光ファイバ線引き
炉に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber drawing furnace used for drawing an optical fiber from an optical fiber preform.
【０００２】[0002]
【従来の技術】従来から、ＶＡＤ法またはＯＶＤ法を用
いて製造した光ファイバ母材を、所定の外径まで縮径す
る延伸工程やファイバ化する工程において使用される光
ファイバ線引き炉として、特開平５−７８１４２号に開
示されたものがある。この光ファイバ線引き炉は線引き
される光ファイバ母材が挿入される炉芯管と、この炉芯
管の外周に配置されて、光ファイバ母材を加熱するヒー
タと、ヒータ熱の外部漏洩を防止するためにヒータの外
周に配置された反射板および耐熱性断熱材と、これらの
構成部材を収納する炉体とを備えて構成されている。2. Description of the Related Art Conventionally, as an optical fiber drawing furnace used in a drawing step for reducing the diameter of an optical fiber preform manufactured by the VAD method or the OVD method to a predetermined outer diameter or a fiber forming step, There is one disclosed in Kaihei 5-78142. This optical fiber drawing furnace has a furnace core tube into which an optical fiber preform to be drawn is inserted, a heater arranged on the outer periphery of the furnace core tube to heat the optical fiber preform, and a heater to prevent external leakage of heat. In order to achieve this, a reflector and a heat-resistant heat insulating material arranged on the outer periphery of the heater, and a furnace body accommodating these components are configured.
【０００３】[0003]
【発明が解決しようとする課題】ところで、このような
従来の光ファイバ線引き炉には、熱逸散防止効果が不十
分であるという問題があった。熱逸散防止効果が不十分
であると、炉長方向での温度分布を急峻なものとするこ
とができず、そのため、光ファイバ母材へ効率よく熱を
伝導することができなくなって、太径の光ファイバ母材
の線引きが不可能になる、線引き中における光ファイバ
母材のコーン形状制御が不確実になるなどの不都合を発
生させていた。However, such a conventional optical fiber drawing furnace has a problem that the effect of preventing heat dissipation is insufficient. If the effect of preventing heat dissipation is insufficient, the temperature distribution in the furnace length direction cannot be made steep, so that heat cannot be efficiently conducted to the optical fiber preform and There have been problems such that it becomes impossible to draw the optical fiber preform of a diameter, and the cone shape control of the optical fiber preform during drawing becomes uncertain.
【０００４】また、熱逸散防止効果が不十分であると、
ヒータに高電力を付与しなければならなくなる結果、ヒ
ータの寿命が縮まるうえ、ヒータからのコンタミネーシ
ョン量が増大してヒータ自身の機械的強度、さらには、
このようなコンタミネーションが付着することにより光
ファイバの機械的強度を悪化させていた。If the effect of preventing heat dissipation is insufficient,
As a result of having to apply high power to the heater, the life of the heater is shortened, and the amount of contamination from the heater is increased to increase the mechanical strength of the heater itself, and further,
The attachment of such contamination deteriorates the mechanical strength of the optical fiber.
【０００５】さらにまた、熱逸散防止効果が不十分であ
ると、線引きが光ファイバの線引き温度２０００℃程度
の高温であるためにエネルギーロスが多大なものとな
り、このようなエネルギーロスをできるかぎり小さくす
るために耐熱性断熱材の厚みを増やす等の対策を取らね
ばならず、その分、炉が大型化していた。Further, if the effect of preventing heat dissipation is insufficient, the energy loss becomes large because the fiber drawing temperature is as high as about 2000 ° C. for drawing the optical fiber, and such energy loss is possible as much as possible. In order to reduce the size, measures such as increasing the thickness of the heat resistant heat insulating material had to be taken, and the furnace had to be enlarged accordingly.
【０００６】したがって、本発明においては、熱逸散防
止効果の良好な光ファイバ線引き炉の提供を目的として
いる。Therefore, it is an object of the present invention to provide an optical fiber drawing furnace having a good heat dissipation prevention effect.
【０００７】[0007]
【課題を解決するための手段】このような目的を達成す
るために、本発明においては、線引きされる光ファイバ
母材の周囲に配設された加熱体と、前記加熱体の周囲に
配設された耐熱性断熱材と、これら全体を収納する炉体
とを備えた光ファイバ線引き炉において、前記耐熱性断
熱材は炭素または炭素を含有する材料からなっていると
ともに、その嵩密度は径方向内端部が最も高く径方向外
側にいくにしたがって順次低くなっており、かつ、耐熱
性断熱材の外周面のうち、少なくとも径方向内端面が黒
鉛もしくは熱分解カーボンによって被覆されていること
に特徴を有している。In order to achieve such an object, according to the present invention, a heating body disposed around an optical fiber preform to be drawn and a heating body disposed around the heating body. In the optical fiber drawing furnace provided with the heat-resistant heat insulating material, and a furnace body for accommodating all of them, the heat-resistant heat insulating material is made of carbon or a material containing carbon, and its bulk density is in the radial direction. The inner end is the highest and becomes gradually lower toward the outer side in the radial direction, and at least the inner end surface in the radial direction of the outer peripheral surface of the heat resistant heat insulating material is covered with graphite or pyrolytic carbon. have.
【０００８】[0008]
【作用】上記構成によれば、炭素または炭素を含有する
材料からなる耐熱性断熱材は嵩密度が高いほど熱輻射効
果が高まる一方、嵩密度が低いほど熱伝導率が低下して
断熱効果が高まる。そこで、加熱体の熱が直接到達する
径方向内端部を最も嵩密度を高くして輻射効果を高める
とともに、径方向外側にいくにしたがって嵩密度を低く
して断熱効果を高めることにより耐熱性断熱材の熱逸散
防止効果は向上する。According to the above construction, the heat radiation heat insulating material made of carbon or a material containing carbon has a higher heat radiation effect as the bulk density is higher, while the heat conductivity is lower as the bulk density is lower and the heat insulating effect is higher. Increase. Therefore, the heat resistance is improved by increasing the bulk density at the radially inner end where the heat of the heating body directly reaches to increase the radiation effect, and decreasing the bulk density toward the radially outer side to increase the heat insulating effect. The heat dissipation prevention effect of the heat insulating material is improved.
【０００９】また、耐熱性断熱材の外周面のうち少なく
とも径方向内端面が黒鉛もしくは熱分解カーボンによっ
て被覆されているので、これら被覆材によって熱輻射効
果はさらに高められる。Since at least the radially inner end surface of the outer peripheral surface of the heat resistant heat insulating material is coated with graphite or pyrolytic carbon, the heat radiation effect is further enhanced by these coating materials.
【００１０】[0010]
【実施例】以下、本発明の一実施例を図面を参照して詳
細に説明する。図１は本発明の一実施例の光ファイバ線
引き炉の構成を示す一部切欠側面図である。この光ファ
イバ線引き炉１は光ファイバ母材Ａが挿入される炉芯管
２を備えている。炉芯管２は円筒形をしており例えばグ
ラファイトから構成されている。この炉芯管２の周囲に
はヒータ３が配設されている。ヒータ３は例えばカーボ
ン抵抗等から構成されている。ヒータ３の周囲には反射
板４が配設されている。反射板４はタングステンとモリ
ブデンとの合金といった耐熱性の優れた金属の円筒体か
らなっており、このように構成された反射板４が複数、
炉芯管２と同心状に配置されている。反射板４の周囲に
は反射板４を囲んで耐熱性断熱材５が配設されている。
耐熱性断熱材５はカーボンフェルトといった、炭素また
は炭素を含有した材料からなっており、厚肉の円筒体形
状をしている。さらに、耐熱性断熱材５の周囲が炉体６
によって囲まれている。なお、炉体６内や炉芯管２内に
形成された空間には図示しない不活性ガス供給手段から
不活性ガスが供給されており、この不活性ガスによって
ヒータ３や耐熱性断熱材５等の酸化消耗が防止されてい
る。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a partially cutaway side view showing the configuration of an optical fiber drawing furnace according to an embodiment of the present invention. This optical fiber drawing furnace 1 includes a furnace core tube 2 into which an optical fiber preform A is inserted. The furnace core tube 2 has a cylindrical shape and is made of, for example, graphite. A heater 3 is arranged around the furnace core tube 2. The heater 3 is composed of, for example, a carbon resistor or the like. A reflector 4 is arranged around the heater 3. The reflection plate 4 is made of a metal cylindrical body having excellent heat resistance such as an alloy of tungsten and molybdenum.
It is arranged concentrically with the furnace core tube 2. A heat resistant heat insulating material 5 is provided around the reflection plate 4 so as to surround the reflection plate 4.
The heat resistant heat insulating material 5 is made of carbon or a material containing carbon, such as carbon felt, and has a thick cylindrical shape. Further, the periphery of the heat resistant heat insulating material 5 is the furnace body 6
Is surrounded by. An inert gas is supplied to the space formed in the furnace body 6 and the furnace core tube 2 from an inert gas supply means (not shown), and the heater 3 and the heat-resistant heat insulating material 5 are supplied by the inert gas. Oxidative consumption of is prevented.
【００１１】この光ファイバ線引き炉１は耐熱性断熱材
５の構造に特徴がある。すなわち、耐熱性断熱材５はそ
の径方向内端が最も嵩密度が高く、径方向外側にいくに
したがって嵩密度が低くなっている。具体的には、例え
ば、径方向内端部の嵩密度が０．１７ｇ／ｃｍ3程度と
なっているとともに径方向外側にいくにしたがって順次
嵩密度が低くなっていき、最外端では０．１５ｇ／ｃｍ
3程度となっている。さらに、このように嵩密度に変化
を持たせた耐熱性断熱材５の周囲全面が黒鉛、もしくは
熱分解カーボンからなる被覆材７によって被覆されてい
る。The optical fiber drawing furnace 1 is characterized by the structure of the heat resistant heat insulating material 5. That is, the heat-resistant heat-insulating material 5 has the highest bulk density at the radially inner end, and the bulk density becomes lower toward the radially outer side. Specifically, for example, the bulk density of the inner end in the radial direction is about 0.17 g / cm 3, the bulk density gradually decreases toward the outer side in the radial direction, and the bulk density becomes 0. 15 g / cm
It is about 3 . Further, the entire surface of the heat-resistant heat insulating material 5 having such a change in bulk density is covered with the covering material 7 made of graphite or pyrolytic carbon.
【００１２】この光ファイバ線引き炉１は耐熱性断熱材
５を上記のように構成しているので次のような効果があ
る。すなわち、炭素または炭素を含有する材料から構成
された耐熱性断熱材５は光ファイバ線引き炉１の２００
０℃程度という炉内温度にも耐え得る性能を有している
一方、嵩密度が高いほど熱輻射効果が高く、嵩密度が低
いほど熱伝導率が低下して断熱効果が高まるという特徴
がある。そこで、ヒータ３の熱が直接到達する径方向内
端部を最も嵩密度を高くして輻射効果を高めるととも
に、径方向外側にいくにしたがって順次嵩密度を低くし
て断熱効果を高めることにより耐熱性断熱材５の熱逸散
防止効果を向上させている。また、耐熱性断熱材５の外
周面を黒鉛もしくに熱分解カーボンかなる被覆材７によ
って被覆しているので、これら被覆材７によって径方向
内端面５ａの熱輻射効果はさらに高められることにな
る。The optical fiber drawing furnace 1 has the following effects because the heat-resistant heat insulating material 5 is constructed as described above. That is, the heat-resistant heat insulating material 5 made of carbon or a material containing carbon is 200
While it has the ability to withstand a furnace temperature of about 0 ° C, the higher the bulk density is, the higher the heat radiation effect is, and the lower the bulk density is, the lower the thermal conductivity is and the higher the heat insulating effect is. . Therefore, the radial inner end where the heat of the heater 3 directly reaches has the highest bulk density to enhance the radiation effect, and the bulk density is gradually decreased toward the radially outer side to enhance the heat insulating effect. The heat dissipation effect of the heat insulating material 5 is improved. Further, since the outer peripheral surface of the heat resistant heat insulating material 5 is coated with the coating material 7 made of graphite or pyrolytic carbon, the thermal radiation effect of the radial inner end surface 5a is further enhanced by these coating materials 7. Become.
【００１３】このように構成することにより、具体的に
は、図２に示すデータのように、２００ｍｍ程度の炉長
を有する光ファイバ線引き炉において、従来の光ファイ
バ線引き炉の構成を採用した場合、図中、破線で示す炉
長方向温度分布を示すのに対して、本発明の光ファイバ
線引き炉１の構成を採用した場合には、図中実線で示す
炉長方向温度分布を示し、本発明の光ファイバ線引き炉
１は、従来のものに比べて急峻な炉長方向温度分布が得
られる。With such a configuration, specifically, as shown in the data shown in FIG. 2, in the optical fiber drawing furnace having a furnace length of about 200 mm, the conventional optical fiber drawing furnace is used. While the temperature distribution in the furnace length direction shown by the broken line is shown in the figure, when the configuration of the optical fiber drawing furnace 1 of the present invention is adopted, the temperature distribution in the furnace length direction shown by the solid line in the figure is shown. The optical fiber drawing furnace 1 of the present invention can obtain a sharper temperature distribution in the furnace length direction than the conventional one.
【００１４】さらには、本実施例の光ファイバ線引き炉
１では、耐熱性断熱材５の周囲全体を黒鉛、もしくは熱
分解カーボンからなる被覆材７で被覆しているので、耐
熱性断熱材５の表面が熱によって剥離することを防止で
き、このような剥離物によるコンタミネーションでヒー
タ３，反射板４，炉体６等の寿命が縮まるといった不都
合を防止できるという効果がある。Further, in the optical fiber drawing furnace 1 of the present embodiment, the entire periphery of the heat resistant heat insulating material 5 is covered with the covering material 7 made of graphite or pyrolytic carbon. There is an effect that the surface can be prevented from peeling due to heat, and the inconvenience of shortening the life of the heater 3, the reflection plate 4, the furnace body 6 and the like due to contamination by such peeled substances can be prevented.
【００１５】ところで、上記実施例では、単一の耐熱性
断熱材５を備え、この耐熱性断熱材５の嵩密度を順次径
方向外側にいくにしたがって低くしていたが、本発明は
このような構成に限るものではく、幾層にも同心状に互
いに密接して配設した複数の耐熱性断熱管から耐熱性断
熱材を構成するととに、これら複数の耐熱性断熱管の嵩
密接を内側のものほど高くすることによって耐熱性断熱
材を構成してもよい。In the above embodiment, a single heat-resistant heat insulating material 5 is provided, and the bulk density of this heat-resistant heat insulating material 5 is gradually lowered outward in the radial direction. However, the heat-resistant heat-insulating material is composed of a plurality of heat-resistant heat-insulating tubes that are concentrically arranged in close contact with each other in multiple layers. The heat resistant heat insulating material may be formed by increasing the height of the inner one.
【００１６】[0016]
【発明の効果】以上のように本発明によれば、熱逸散防
止効果が向上したので、炉長方向での温度分布を急峻な
ものとすることができた。そのため、光ファイバ母材に
効率よく熱を伝導することができ、太径の光ファイバ母
材であっても線引きが可能になるうえ、線引き中におけ
る光ファイバ母材のコーン形状制御を確実に行えるよう
になった。As described above, according to the present invention, the effect of preventing heat dissipation is improved, so that the temperature distribution in the furnace length direction can be made steep. Therefore, heat can be efficiently conducted to the optical fiber preform, and even a large diameter optical fiber preform can be drawn, and the cone shape control of the optical fiber preform during the drawing can be reliably performed. It became so.
【００１７】また、熱逸散防止効果が向上したので、加
熱体に付与する電力の低減が図れるようになり、加熱体
の長寿命化が図れるうえ、加熱体からのコンタミネーシ
ョン量が減少して加熱体自身や光ファイバの機械的強度
を向上させることができた。Further, since the heat dissipation prevention effect is improved, the electric power applied to the heating body can be reduced, the life of the heating body can be extended, and the amount of contamination from the heating body can be reduced. It was possible to improve the mechanical strength of the heating element itself and the optical fiber.
【００１８】さらに、熱逸散防止効果が向上してエネル
ギーロスが減少したので、このようなエネルギーロスを
減らすために耐熱性断熱材の厚みを増やす等の対策を取
る必要がなくなり、その分、炉の小型化が達成できた。Further, since the heat dissipation prevention effect is improved and the energy loss is reduced, it is not necessary to take measures such as increasing the thickness of the heat resistant heat insulating material in order to reduce the energy loss. The miniaturization of the furnace was achieved.
【図１】本発明の一実施例の光ファイバ線引き炉の構成
を示す一部切欠側面図である。FIG. 1 is a partially cutaway side view showing a configuration of an optical fiber drawing furnace according to an embodiment of the present invention.
【図２】軸長方向での温度分布データを実施例と従来例
とで比較した線図である。FIG. 2 is a diagram comparing temperature distribution data in the axial direction between an example and a conventional example.
２ 炉芯管 ３ ヒータ ５ 耐熱性断熱材 ５ａ 径方向内端面 ６ 炉体 ７ 被覆材 2 core tube 3 heater 5 heat resistant heat insulating material 5a radial inner end surface 6 furnace body 7 coating material
Claims (1)
された加熱体と、前記加熱体の周囲に配設された耐熱性
断熱材と、これら全体を収納する炉体とを備えた光ファ
イバ線引き炉であって、 前記耐熱性断熱材は炭素または炭素を含有する材料から
なっているとともに、その嵩密度は径方向内端部が最も
高く径方向外側にいくにしたがって順次低くなってお
り、かつ、耐熱性断熱材の外周面のうち少なくとも径方
向内端面が黒鉛もしくは熱分解カーボンによって被覆さ
れていることを特徴とする光ファイバ線引き炉。1. A heating body arranged around an optical fiber preform to be drawn, a heat resistant heat insulating material arranged around the heating body, and a furnace body accommodating all of them. In the optical fiber drawing furnace, the heat resistant heat insulating material is made of carbon or a material containing carbon, and the bulk density thereof is highest at the radially inner end and gradually decreases toward the radially outer side. An optical fiber drawing furnace characterized in that at least the radially inner end surface of the outer peripheral surface of the heat resistant heat insulating material is coated with graphite or pyrolytic carbon.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22565693A JPH0781967A (en) | 1993-09-10 | 1993-09-10 | Optical fiber drawing furnace |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22565693A JPH0781967A (en) | 1993-09-10 | 1993-09-10 | Optical fiber drawing furnace |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0781967A true JPH0781967A (en) | 1995-03-28 |
Family
ID=16832717
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22565693A Pending JPH0781967A (en) | 1993-09-10 | 1993-09-10 | Optical fiber drawing furnace |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0781967A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0867412A1 (en) * | 1997-03-27 | 1998-09-30 | Alcatel | Thermal insulation of a furnace for drawing optical fibres |
| JP2002211942A (en) * | 2001-01-10 | 2002-07-31 | Shin Etsu Chem Co Ltd | Drawing machine for glass perform |
| WO2006075461A1 (en) * | 2005-01-14 | 2006-07-20 | Shin-Etsu Chemical Co., Ltd. | Drawing method of optical fiber |
-
1993
- 1993-09-10 JP JP22565693A patent/JPH0781967A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0867412A1 (en) * | 1997-03-27 | 1998-09-30 | Alcatel | Thermal insulation of a furnace for drawing optical fibres |
| JP2002211942A (en) * | 2001-01-10 | 2002-07-31 | Shin Etsu Chem Co Ltd | Drawing machine for glass perform |
| WO2006075461A1 (en) * | 2005-01-14 | 2006-07-20 | Shin-Etsu Chemical Co., Ltd. | Drawing method of optical fiber |
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