JPH02124733A - Heating furnace for glass base material for optical fiber - Google Patents
Heating furnace for glass base material for optical fiberInfo
- Publication number
- JPH02124733A JPH02124733A JP27835488A JP27835488A JPH02124733A JP H02124733 A JPH02124733 A JP H02124733A JP 27835488 A JP27835488 A JP 27835488A JP 27835488 A JP27835488 A JP 27835488A JP H02124733 A JPH02124733 A JP H02124733A
- Authority
- JP
- Japan
- Prior art keywords
- core tube
- furnace core
- furnace
- optical fiber
- inner layer
- 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.)
- Granted
Links
- 238000010438 heat treatment Methods 0.000 title claims abstract description 35
- 239000011521 glass Substances 0.000 title claims abstract description 19
- 239000013307 optical fiber Substances 0.000 title claims abstract description 17
- 239000000463 material Substances 0.000 title claims description 18
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 19
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 17
- 239000011261 inert gas Substances 0.000 claims abstract description 14
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 14
- 229910052731 fluorine Inorganic materials 0.000 claims abstract description 8
- 239000011737 fluorine Substances 0.000 claims abstract description 8
- 239000002245 particle Substances 0.000 claims abstract description 6
- 239000005373 porous glass Substances 0.000 claims abstract description 5
- 239000007789 gas Substances 0.000 claims description 11
- 239000000377 silicon dioxide Substances 0.000 claims description 3
- 150000002222 fluorine compounds Chemical class 0.000 claims description 2
- PXGOKWXKJXAPGV-UHFFFAOYSA-N Fluorine Chemical compound FF PXGOKWXKJXAPGV-UHFFFAOYSA-N 0.000 claims 1
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 abstract description 7
- 239000010453 quartz Substances 0.000 abstract description 7
- 230000003647 oxidation Effects 0.000 abstract description 6
- 238000007254 oxidation reaction Methods 0.000 abstract description 6
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 abstract description 4
- 229910052757 nitrogen Inorganic materials 0.000 abstract description 2
- 239000011148 porous material Substances 0.000 abstract description 2
- 230000015572 biosynthetic process Effects 0.000 abstract 1
- 239000002585 base Substances 0.000 description 14
- 238000000034 method Methods 0.000 description 11
- 230000018044 dehydration Effects 0.000 description 6
- 238000006297 dehydration reaction Methods 0.000 description 6
- 239000001307 helium Substances 0.000 description 6
- 229910052734 helium Inorganic materials 0.000 description 6
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 6
- 239000010419 fine particle Substances 0.000 description 4
- 238000004334 fluoridation Methods 0.000 description 4
- 239000012535 impurity Substances 0.000 description 4
- 239000000835 fiber Substances 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 238000000280 densification Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000005192 partition Methods 0.000 description 2
- 238000003462 Bender reaction Methods 0.000 description 1
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 150000001721 carbon Chemical class 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 238000005352 clarification Methods 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 239000002019 doping agent Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 238000005470 impregnation Methods 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000002834 transmittance Methods 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
- C03B2201/00—Type of glass produced
- C03B2201/06—Doped silica-based glasses
- C03B2201/08—Doped silica-based glasses doped with boron or fluorine or other refractive index decreasing dopant
- C03B2201/12—Doped silica-based glasses doped with boron or fluorine or other refractive index decreasing dopant doped with fluorine
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、光ファイバ用母材の加熱炉に関し、更に詳し
くは、石英系ガラス微粒子体から成る多孔質ガラス母材
を加熱し、フッ素添加および透明化する為の加熱炉に関
する。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a heating furnace for an optical fiber base material, and more specifically, the present invention relates to a heating furnace for an optical fiber base material, and more specifically, for heating a porous glass base material made of silica-based glass fine particles, and adding fluorine to the base material. and regarding heating furnaces for transparency.
本発明の加熱炉は、ガラス母材に対づ−る不純物元素の
混入を防止することができ、かつ耐久性の優れたもので
ある。The heating furnace of the present invention can prevent contamination of impurity elements into the glass base material and has excellent durability.
［従来の技術］
ＶＡＤ法またはＯＶＤ法を用いて光ファイバ用プリフォ
ームを製造するためには、ＶＡＤ法またはＯＶＤ法で得
られたガラス微粒子積層体を脱水し、稠密・透明化する
必要がある。また屈折率調整用のドーパントであるフッ
素は、この脱水、稠密・透明化工程の進行中に添加され
ろ。これらの脱水、稠密・透明化、フッ素添加工程では
、炉芯管を持った加熱炉が使われる。そして、この炉芯
管の材質としては、アルミナ（特公昭５７−４００９６
号公報および米国特許第４，３３８，１１１号参照）、
石英ガラス（特公昭５８−５８２９９号、同５８−４２
１３６号参照）が使われていｊコ。[Prior art] In order to manufacture an optical fiber preform using the VAD method or OVD method, it is necessary to dehydrate the glass fine particle laminate obtained by the VAD method or OVD method to make it dense and transparent. . Also, fluorine, which is a dopant for adjusting the refractive index, is added during the dehydration, densification, and transparency steps. A heating furnace with a furnace core tube is used in these dehydration, densification/clarification, and fluoridation processes. The material of this furnace core tube is alumina (Special Publication No. 57-40096
(see US Pat. No. 4,338,111),
Quartz glass (Special Publication No. 58-58299, No. 58-42)
136) is used.
しかしながら、曲者では、不純物（たとえば、アルカリ
）が飛散し、製品が失透しやすいという問題点があり、
後者には不純物（銅および水酸基）が含まれ、製品の光
学吸収が増加すること、さらに耐熱性が不足していると
いう問題点があった。However, benders have the problem that impurities (e.g. alkali) scatter and the product tends to devitrify.
The latter contains impurities (copper and hydroxyl groups), which increases the optical absorption of the product and also has problems in that it lacks heat resistance.
これらの問題点を解決するため、本発明者等が検討を行
なった結果、炉芯管の材質としてはカーボンが最適であ
るとの結論に達した。カーボン炉芯管を使った場合の加
熱炉の様々な形態および使用方法については特願昭６３
−３４５９１、発明の名称：光ファイバ用ガラス母材の
加熱炉および製法）および国際出願公開ＷＯ３８１０６
１４５（ＰＣ′ｌ’／ＪＰ８８１００１５１）ｊ、：詳
しく３己されている。In order to solve these problems, the inventors of the present invention conducted studies and came to the conclusion that carbon is the most suitable material for the furnace core tube. Various forms and usage methods of heating furnaces using carbon furnace core tubes are disclosed in Japanese Patent Application No. 1983.
-34591, Title of Invention: Heating Furnace and Manufacturing Method for Glass Preform for Optical Fiber) and International Application Publication WO38106
145 (PC'l'/JP88100151)j: 3 details have been provided.
［発明が解決しようとする課題］ 従来のこの種の装置は第２図のように構成されている。[Problem to be solved by the invention] A conventional device of this type is constructed as shown in FIG.
第２図中、１〜７は後記第１図の加熱炉と同じ要素であ
り、３４．３５および３６は、３分割された炉芯管の上
部、中間部および下部を示す。この様な構造の加熱炉で
は、製品出入り時に炉芯管内に大気が混入する。そのた
めカーボン炉芯管内面の酸化がおこる。その結果、製造
されたガラス母材から作られるファイバではガラス母材
に付着するカーボンに起因して低強度部分が多くなると
ともに、炉芯管の寿命が短かくなる。この様な酸化を防
ぐ方法の一つは、既に前記特許出願に提案されている。In FIG. 2, 1 to 7 are the same elements as the heating furnace shown in FIG. 1, which will be described later, and 34, 35, and 36 indicate the upper, middle, and lower parts of the furnace core tube divided into three parts. In a heating furnace having such a structure, air enters the furnace core tube when products are taken in and out. This causes oxidation of the inner surface of the carbon furnace core tube. As a result, fibers made from the manufactured glass base material have many low-strength parts due to carbon adhering to the glass base material, and the life of the furnace core tube is shortened. One method for preventing such oxidation has already been proposed in the aforementioned patent application.
それは第３図の様な前室を持つものである。この加熱炉
は、第２図の加熱炉に加え、前室Ｉｔ、前室ガス出口１
４、前室ガス人口１５および仕切り板１６を有する。こ
の加熱炉の場合、設備の高さ（全高）が第２図のものの
１゜５倍にもなってしまう。すなわち、前記特許出願に
開示の方法では、炉芯管の酸化は防げろものの経済的な
設備とは言えなかった。It has a front chamber as shown in Figure 3. In addition to the heating furnace shown in FIG. 2, this heating furnace includes a front chamber It, a front chamber gas outlet 1
4. It has a front chamber gas port 15 and a partition plate 16. In the case of this heating furnace, the height (total height) of the equipment is 1.5 times that of the one in Figure 2. That is, although the method disclosed in the above patent application could prevent oxidation of the furnace core tube, it could not be said to be an economical equipment.
し課題を解決するための手段］
本発明は、加熱炉の発熱体の内側に配置されて加熱雰囲
気と発熱体とを隔離する炉芯管を２重構造とし、内層と
外層との間に不活性ガス雰囲気を形成することにより、
前記問題点を解決した。[Means for Solving the Problems] The present invention provides a furnace core tube which is arranged inside a heating element of a heating furnace and isolates the heating atmosphere from the heating element, and has a double structure, and there is no space between the inner layer and the outer layer. By forming an active gas atmosphere,
The above problems have been solved.
すなわち、本発明は、石英系ガラス微粒子体から成る光
ファイバ用多孔質ガラス母材を、フッ素化合物を含む気
体雰囲気中で加熱処理することにより、フッ素添加およ
び透明化して光ファイバ用ガラス母材とする加熱炉であ
って、発熱体および発熱体の内側に配置されて加熱雰囲
気と発熱体とを隔離する炉芯管の少なくとも中間部を２
重構造とし、炉芯管の内層は高純度カーボンから形成さ
れており、炉芯管の内層と外層との間に不活性ガス雰囲
気を有することを特徴とする光ファイバ母材の加熱炉を
提供するものである。That is, the present invention heat-treats a porous glass base material for optical fibers made of silica-based glass fine particles in a gas atmosphere containing a fluorine compound to add fluorine and make the glass base material for optical fibers transparent. A heating furnace comprising a heating element and at least an intermediate portion of a furnace core tube disposed inside the heating element to isolate the heating atmosphere from the heating element.
Provided is a heating furnace for an optical fiber base material, which has a heavy structure, the inner layer of the furnace core tube is made of high-purity carbon, and an inert gas atmosphere is provided between the inner layer and the outer layer of the furnace core tube. It is something to do.
本発明を添付図面を参照して説明する。The invention will now be described with reference to the accompanying drawings.
第１図は、本発明の１つの態様の、光ファイバ用母材の
加熱炉を示す概略断面図である。第１図中、ｌは多孔質
母材、２は支持棒、３は炉芯管、４は発熱体、５は炉本
体、６は不活性ガスの導入口、７は雰囲気ガス（例えば
５Ｆｌ１１ヘリウム等）の導入口である。第１図の加熱
炉の炉芯管は、′ヒータで加熱される中間部が２重構造
になっているが、炉芯管全体を２重構造にしてもよい。FIG. 1 is a schematic cross-sectional view showing a heating furnace for an optical fiber preform according to one embodiment of the present invention. In Figure 1, l is a porous base material, 2 is a support rod, 3 is a furnace core tube, 4 is a heating element, 5 is a furnace body, 6 is an inert gas inlet, 7 is an atmospheric gas (for example, 5Fl11 helium etc.). Although the furnace core tube of the heating furnace shown in FIG. 1 has a double structure in the middle portion heated by the heater, the entire furnace core tube may have a double structure.
第１図中、８は、本発明により炉芯管の内層と外層との
間に不活性ガス（例えば、窒素、ヘリウム、アルゴンな
ど）を導入する為の導入口である。In FIG. 1, 8 is an inlet for introducing an inert gas (for example, nitrogen, helium, argon, etc.) between the inner layer and outer layer of the furnace core tube according to the present invention.
［作用］
第１図の導入口８から、不活性ガスを導入することによ
り、炉芯管の内層９と外層ＩＯとの間は陽圧となる。内
層９がカーボン製である（一般的なカーボン材＝等方成
形による焼結晶はＬ Ｑ ’ｃｍ２／秒程度の透過率を
持つ）ので、導入された不活性ガスは、カーボンの気孔
を通過して炉芯管内部に吹き出す。そのため、炉芯管内
面近傍は常に不活性ガス雰囲気となり、製品出入れ時に
大気が混入しても、炉芯管内面が酸化されることはなく
なる。また、それによって、最終的に製造される光ファ
イバに低強度部分が含まれることら無くなる。[Operation] By introducing an inert gas through the inlet 8 shown in FIG. 1, a positive pressure is created between the inner layer 9 and the outer layer IO of the furnace core tube. Since the inner layer 9 is made of carbon (general carbon material = sintered crystal produced by isotropic molding has a transmittance of about L Q 'cm2/sec), the introduced inert gas passes through the pores of the carbon. It blows out inside the furnace core tube. Therefore, the vicinity of the inner surface of the furnace core tube is always in an inert gas atmosphere, and even if the atmosphere is mixed in when loading and unloading products, the inner surface of the furnace core tube will not be oxidized. It also eliminates the inclusion of low-strength portions in the final manufactured optical fiber.
さらに設備全高は今まで通りであるので、低コストな設
備となる。また、外層ＩＯにカーボン管を使う場合には
炉芯管内部から炉体（第１図５）内部への塩素、フッ素
系ガスのしみ出しも防ぐことかできる。Furthermore, the overall height of the equipment remains the same, resulting in a low-cost equipment. Furthermore, when a carbon tube is used for the outer layer IO, it is also possible to prevent chlorine and fluorine gases from seeping from the inside of the furnace core tube into the inside of the furnace body (FIG. 1, 5).
外層１０に石英管を使う場合には、石英管を冷却できる
ので、外側石英管の寿命か伸びる。If a quartz tube is used for the outer layer 10, the quartz tube can be cooled, thereby extending the life of the outer quartz tube.
［実施例］
実姉例１
第１図に示す装置をガラス微粒子積層体の脱水、フッ素
添加および透明化に使用した。[Example] Actual Example 1 The apparatus shown in FIG. 1 was used for dehydration, fluoridation, and transparency of a glass particle laminate.
不活性ガス導入口８からは、ヘリウムを１０Ｑ／分の速
度で導入した。その時、内層９と外層１０とにはさまれ
た部分の圧は、炉芯管内に対してモ３ ｍｍａｑ、炉体
内に対して＋Ｉ ｍｍａＱであった。ガラス微粒子積層
体３０本の処理を以下の条件で行った。Helium was introduced from the inert gas inlet 8 at a rate of 10 Q/min. At that time, the pressure at the portion sandwiched between the inner layer 9 and the outer layer 10 was 3 mmaQ in the furnace core tube and +1 mmaQ in the furnace body. Thirty glass particle laminates were processed under the following conditions.
第１段：脱水不純物除去工程
炉内雰囲気：ヘリウム９８％十塩素ガス２％ヒータ表面
温度＋ １，１００°Ｃ
トラバース速度・ ６肩１／分
第２段・フッ素含浸工程
炉内雰囲気：ヘリウム９７％＋Ｓ ＩＦ ４３％ヒータ
表面温度：１．３００°Ｃ
トラバース速度：Ｇｔｔｕｔｒ１分
第３段・透分化３段
炉内雰囲気：ヘリウム９７％＋５ｉＦａ３％ヒータ表面
温度： １，６００°Ｃ
トラバース速度・ ６次肩／分
全ガラス微粒子積層体の処理後も、炉芯管内面の酸化は
全く見られず、また、焼結体（透明ガラス母材）表面へ
のカーボン粉の付着は無かった。1st stage: Dehydration impurity removal process Furnace atmosphere: 98% helium, 2% decachlorine gas Heater surface temperature + 1,100°C Traverse speed: 6 shoulders 1/min 2nd stage: Fluorine impregnation process Furnace atmosphere: Helium 97 %+S IF 43% Heater surface temperature: 1.300°C Traverse speed: Gttutr 1 minute 3rd stage / permeation 3rd stage Furnace atmosphere: Helium 97% + 5iFa 3% Heater surface temperature: 1,600°C Traverse speed / 6th Even after the treatment of the shoulder/minute all-glass fine particle laminate, no oxidation was observed on the inner surface of the furnace core tube, and no carbon powder was attached to the surface of the sintered body (transparent glass base material).
得られた透明ガラス母材を延伸して製造した光ファイバ
は、９０％以上が５ 、５ ｋｇ以上の破断強度を有し
ていた。また炉体内部の発錆は無かった。More than 90% of the optical fibers manufactured by stretching the obtained transparent glass preform had a breaking strength of 5.5 kg or more. Also, there was no rust inside the furnace body.
比較例１
第２図に示す装置をガラス微粒子積層体の脱水、フッ素
添加および透明化に使用した。実施例１と同様に処理を
行なったところ、カーボン製炉芯管の内面が酸化し、１
３本口の焼結体から焼結体表面にカーボン粉か付着して
いた。このカーボン扮が付着した母材から製造したファ
イバては、５゜５ｋｇ以上の破断強度を持つものが３０
％しか無かった。炉体内部は激しく発錆していた。Comparative Example 1 The apparatus shown in FIG. 2 was used for dehydration, fluoridation, and transparency of a glass particle laminate. When the treatment was carried out in the same manner as in Example 1, the inner surface of the carbon furnace core tube was oxidized and
Carbon powder was found adhering to the surface of the three-mouthed sintered body. Fibers manufactured from the base material to which this carbon layer is attached have a breaking strength of 5.5 kg or more.
There was only %. The inside of the furnace body was severely rusted.
比較例２
第３図に示す装置をガラス微粒子積層体の脱水、フッ素
添加および透明化に使用した。３０本の処理を行なった
。カーボン製炉芯管の内面は酸化しておらず、焼結体表
面にカーボン粉が付着することら無かった。得られた先
ファイバの９０％以上は、５ 、５ ｋｇ以上の破断強
度を持っていた。また炉体内部は激しく発錆していた。Comparative Example 2 The apparatus shown in FIG. 3 was used for dehydration, fluoridation, and transparency of a glass particle laminate. Thirty pieces were processed. The inner surface of the carbon furnace core tube was not oxidized, and no carbon powder was found to adhere to the surface of the sintered body. More than 90% of the obtained pre-fibers had a breaking strength of 5.5 kg or more. Additionally, the inside of the furnace body was severely rusted.
ちなみに第３図の設備の全高は多孔質ガラス母村長の約
６倍であるのに対し、第１図の設備は約４倍であった。By the way, the total height of the equipment shown in Figure 3 is about six times that of the porous glass mother village chief, while the equipment shown in Figure 1 is about four times as tall.
［発明の効果］
１ カーボン炉芯管内面の酸化が防げる。その結果、得
られる光ファイバの低強度部分が少なくなる。また、内
側のカーホン炉芯管の寿命が伸びる。[Effects of the invention] 1. Oxidation of the inner surface of the carbon furnace core tube can be prevented. As a result, the resulting optical fiber has fewer low-strength portions. It also extends the life of the inner carphone furnace core tube.
２ 、前室を設ける方法に比して設備の全高が１／１．
５となり、低コスト設備となる。2. The total height of the equipment is 1/1 that of the method with a front chamber.
5, making it a low-cost facility.
３、炉芯管の外層にカーボン管を使うと、炉体の腐蝕が
防げる。3. Using a carbon tube for the outer layer of the furnace core tube will prevent corrosion of the furnace body.
４ 炉芯管あ外層に石英管を使った場合、不活性ガスに
よって石英炉芯管が冷され、石英炉芯管の寿命が伸びる
。4. When a quartz tube is used as the outer layer of the furnace core tube, the inert gas cools the quartz furnace tube, extending the life of the quartz furnace tube.
第１図は、本発明の加熱炉の断面図、
第２図および第３図は、従来技術の加熱炉の断面図であ
る。
１・・多孔質母材
３・・・炉芯管
５・・炉本体
７・・・雰囲気ガス導入口
９ 炉芯管内層
１１・・・前室
１５・前室ガス人口
３４ 炉芯管上部
３６・・炉芯管下部
２ ・支持棒
、１ ヒーター
６・・・不活性ガス導入口
８・・不活性ガス導入口
１０・・・炉芯管外層
１４・前室ガス出口
１６ ・仕切り仮
３５・炉芯管中間部FIG. 1 is a sectional view of a heating furnace of the present invention, and FIGS. 2 and 3 are sectional views of a heating furnace of the prior art. 1 Porous base material 3 Furnace core tube 5 Furnace body 7 Atmosphere gas inlet 9 Furnace core tube inner layer 11 Front chamber 15 Front chamber gas population 34 Furnace core tube upper part 36・Furnace core tube lower part 2 ・Support rod, 1 Heater 6...Inert gas inlet 8...Inert gas inlet 10...Furnace core tube outer layer 14・Pre-chamber gas outlet 16 ・Temporary partition 35・Middle part of furnace core tube
Claims (1)
ガラス母材を、フッ素化合物を含む気体雰囲気中で加熱
処理することにより、フッ素添加および透明化して光フ
ァイバ用ガラス母材とする加熱炉であって、発熱体およ
び発熱体の内側に配置されて加熱雰囲気と発熱体とを隔
離する炉芯管の少なくとも中間部を２重構造とし、炉芯
管の内層は高純度カーボンから形成されており、炉芯管
の内層と外層との間に不活性ガス雰囲気を有することを
特徴とする光ファイバ母材の加熱炉。1. A porous glass base material for optical fibers made of silica-based glass particles is heated in a gas atmosphere containing a fluorine compound to add fluorine and make it transparent in a heating furnace. The heating element and the furnace core tube arranged inside the heating element to isolate the heated atmosphere and the heating element have a double structure at least in the middle part, and the inner layer of the furnace core tube is made of high-purity carbon. A heating furnace for an optical fiber preform, characterized in that an inert gas atmosphere is provided between an inner layer and an outer layer of a furnace core tube.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27835488A JP2551642B2 (en) | 1988-11-01 | 1988-11-01 | Glass base material heating furnace for optical fiber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27835488A JP2551642B2 (en) | 1988-11-01 | 1988-11-01 | Glass base material heating furnace for optical fiber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02124733A true JPH02124733A (en) | 1990-05-14 |
| JP2551642B2 JP2551642B2 (en) | 1996-11-06 |
Family
ID=17596166
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP27835488A Expired - Lifetime JP2551642B2 (en) | 1988-11-01 | 1988-11-01 | Glass base material heating furnace for optical fiber |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2551642B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114436521A (en) * | 2022-04-08 | 2022-05-06 | 武汉友美科自动化有限公司 | Device and method for preparing optical fiber preform rod by plasma chemical vapor deposition outside tube |
-
1988
- 1988-11-01 JP JP27835488A patent/JP2551642B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114436521A (en) * | 2022-04-08 | 2022-05-06 | 武汉友美科自动化有限公司 | Device and method for preparing optical fiber preform rod by plasma chemical vapor deposition outside tube |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2551642B2 (en) | 1996-11-06 |
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