JP2791380B2 - Dehydration sintering furnace for optical fiber preform - Google Patents

Dehydration sintering furnace for optical fiber preform

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Publication number
JP2791380B2
JP2791380B2 JP1033454A JP3345489A JP2791380B2 JP 2791380 B2 JP2791380 B2 JP 2791380B2 JP 1033454 A JP1033454 A JP 1033454A JP 3345489 A JP3345489 A JP 3345489A JP 2791380 B2 JP2791380 B2 JP 2791380B2
Authority
JP
Japan
Prior art keywords
chamber
gas
partition wall
muffle
optical fiber
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.)
Expired - Fee Related
Application number
JP1033454A
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Japanese (ja)
Other versions
JPH02212325A (en
Inventor
光一 原田
啓一郎 塩屋
亮二 鈴木
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fujikura Ltd
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Fujikura Ltd
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Priority to JP1033454A priority Critical patent/JP2791380B2/en
Publication of JPH02212325A publication Critical patent/JPH02212325A/en
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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

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  • 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)

Description

【発明の詳細な説明】 ＜産業上の利用分野＞ 本発明は、光ファイバ母材中の水分等を除去するた
め、加熱焼成し、かつ同時に母材の透明ガラス化を図る
脱水焼結炉に関するものである。Description: TECHNICAL FIELD The present invention relates to a dehydration and sintering furnace that heats and sinters to remove moisture and the like in an optical fiber preform and simultaneously converts the preform into a vitreous transparent glass. Things.

＜従来の技術＞ 従来、このような脱水焼結炉としては、例えば第３図
に示した如き構造のものが使用されている。<Prior Art> Conventionally, as such a dehydration sintering furnace, for example, a furnace having a structure as shown in FIG. 3 is used.

この焼結炉は、内部に、VAD法等により作製された光
ファイバ母材１がガラス棒等の保持材２により懸架され
て収容される、石英製筒体等からなるマッフル３と、こ
のマッフル３の中に脱水剤を含むガスを供給するガス供
給系４と、マッフル３の外周に取り付けられ、このマッ
フル３内の光ファイバ母材１を加熱するヒータ等からな
る加熱部５と、このマッフル３上部に取り付けられ、上
記保持材２が貫通される蓋穴6aを有する蓋６とからな
る。The sintering furnace includes a muffle 3 made of a quartz cylinder or the like in which an optical fiber preform 1 manufactured by a VAD method or the like is suspended and accommodated by a holding material 2 such as a glass rod, and the muffle 3 3, a gas supply system 4 for supplying a gas containing a dehydrating agent, a heating unit 5 attached to the outer periphery of the muffle 3 and including a heater for heating the optical fiber preform 1 in the muffle 3, and a muffle 3 3 and a lid 6 having a lid hole 6a through which the holding material 2 is penetrated.

上記ガス供給系４は、脱水剤となる塩素ガス等を供給
する経路4aと、その濃度調整と空気を排除するためのヘ
リウムガス等を供給する経路4bとを有しており、これら
の両経路4a,4bからの各ガスは、夫々の流量コントロー
ラ7a,7bを通じて調整された後、合流されて、上記マッ
フル３の下部に供給されるようになっている。The gas supply system 4 has a path 4a for supplying a chlorine gas or the like serving as a dehydrating agent, and a path 4b for supplying a helium gas or the like for adjusting the concentration and eliminating air. The gases from 4a, 4b are adjusted through respective flow controllers 7a, 7b, then merged and supplied to the lower part of the muffle 3.

そして、このガス供給系４から供給されたガスは、マ
ッフル３内を上昇した後、蓋穴6aと保持材２との環状の
隙間８から、この隙間８を一種の排気口として、排気さ
れるようになっている。After the gas supplied from the gas supply system 4 rises in the muffle 3, the gas is exhausted from the annular gap 8 between the lid hole 6a and the holding member 2 using the gap 8 as a kind of exhaust port. It has become.

また、上記マッフル３の上部には、通路3a,3bを通じ
て差圧計９および風船バッファ10が接続されており、焼
結時には、マッフル３内の内圧が一定値の範囲内で保持
されるように差圧計９を監視しながら、ガスの供給をコ
ントロールして行っている。Further, a differential pressure gauge 9 and a balloon buffer 10 are connected to the upper part of the muffle 3 through passages 3a and 3b, and a differential pressure is maintained so that the internal pressure in the muffle 3 is maintained within a certain range during sintering. The gas supply is controlled while monitoring the pressure gauge 9.

＜発明が解決しようとする課題＞ ところが、このような従来の脱水焼結炉では、マッフ
ル３内の内圧コントロールにおいて、以下のような点で
未だ不十分であった。<Problems to be solved by the invention> However, such a conventional dehydration sintering furnace is still insufficient in controlling the internal pressure in the muffle 3 in the following points.

というのは、昨今、光ファイバに対する品質要求が高
くなり、母材の脱水焼結にあたっては、マッフル内の内
圧コントールを高精度で行う必要があり、また、同時に
外気の僅かな流入にも厳しく対処しなければならない。In recent years, the demand for optical fiber quality has increased, and when dewatering and sintering the preform, it is necessary to control the internal pressure inside the muffle with high precision, and at the same time severely deal with the slight inflow of outside air. Must.

しかしながら、このような観点に立った場合、上記従
来の脱水焼結炉では、ガスの排気が行われる隙間８は、
上述したように単に保持材２の外径と、この外径に対し
て少々余裕をもって作られた蓋穴6aの内径との径差から
なるものであり、その気密性は不十分で、とてもマッフ
ル内圧を高精度でコントロールすることはできない。However, from this viewpoint, in the conventional dehydration sintering furnace, the gap 8 where gas is exhausted is
As described above, it simply consists of the diameter difference between the outer diameter of the holding material 2 and the inner diameter of the lid hole 6a formed with a margin with respect to this outer diameter. The internal pressure cannot be controlled with high precision.

しかも、上記保持材２にあっては、回転しながら上下
動するものあるため、あまり隙間８を狭くすることは機
能的にも無理であり、また、例え、この隙間８をうまく
十分調整したとして、保持材２の動きにより、微妙な振
動が生じる等の問題もある。さらに、使用する保持材２
には、数種類のものがあり、かつその寸法精度にも多少
のバラ付きがあるため、やはり高い気密性の保持はあま
り望めない。In addition, since the holding member 2 moves up and down while rotating, it is impossible to narrow the gap 8 so much from a functional viewpoint. Also, for example, it is assumed that the gap 8 is adjusted sufficiently. In addition, there is also a problem that the movement of the holding member 2 causes minute vibration. Further, the holding material 2 to be used
There are several types, and there is some variation in the dimensional accuracy, so that high airtightness cannot be expected.

本発明は、このような従来の実情に鑑みてなされたも
のであり、その大きな特徴は、蓋の他に別部材として、
光ファイバ母材の保持材が極めて小さい最適の隙間をも
って貫通されるスリーブを用意し、これを、例えば隔壁
室を有する蓋の内部に着脱自在に取り付けたことにあ
る。The present invention has been made in view of such a conventional situation, and its major feature is that, in addition to the lid, as a separate member,
There is provided a sleeve through which the holding material of the optical fiber preform is penetrated with an extremely small optimum gap, and this is detachably attached to, for example, a lid having a partition chamber.

＜課題を解決するための手段＞ かゝる本発明を、より具体的に示すと、その一つは、
保持材２により懸架された光ファイバ母材１が収容され
るマッフル３と、該マッフル３中に脱水剤を含むガスを
供給するガス供給系４と、前記マッフル３内の光ファイ
バ母材１を加熱する加熱部５と、前記マッフル３上部に
取り付けられ、前記保持材２が貫通される蓋16とを備え
た光ファイバ母材の脱水焼結炉において、前記蓋16を２
重構造とし、その上下に２つの隔壁室R1,R2を設け、下
側の隔壁室R1の底壁16aにはその貫通穴17aを通じて前記
保持材２が貫通されるスリーブ17を挿入、設置する一
方、上側の隔壁室R2の底壁16bには前記スリーブ17が通
る内径の穴21を設けると共に、当該穴21よりその外径が
大きく、かつその貫通穴18aを通じて前記保持材２が貫
通されるスリーブ18を挿入、設置し、さらに、前記上側
の隔壁室R2の上端にはその中央の貫通穴を通じて前記保
持材２が貫通される上蓋部16cを開閉自在に設置して、
前記スリーブ17,18が着脱自在に取り付けられるように
する一方、前記下側の隔壁室R1にはガス供給口19を設け
ると共に、前記上側の隔壁室R2にはガス排出口20を設け
て、前記ガス供給口19から下側の隔壁室R1にガスを供給
すると共に、前記ガス排出口20及び前記上蓋部16cの貫
通穴の隙間から上側の隔壁室R2内のガスを排気するよう
にしたことを特徴とする光ファイバ母材の脱水焼結炉に
ある。<Means for Solving the Problems> The present invention will be described more specifically.
A muffle 3 in which the optical fiber preform 1 suspended by the holding material 2 is accommodated, a gas supply system 4 for supplying a gas containing a dehydrating agent into the muffle 3, and an optical fiber preform 1 in the muffle 3 In a dehydration and sintering furnace for an optical fiber preform comprising a heating unit 5 to be heated and a lid 16 mounted on the muffle 3 and through which the holding material 2 passes, the lid 16 is
A double-walled structure, two partition chambers R 1 , R 2 are provided above and below it, and a sleeve 17 through which the holding material 2 penetrates is inserted into the bottom wall 16a of the lower partition chamber R 1 through its through hole 17a. while installation, with the upper side of the bottom wall 16b of the partition chamber R 2 is provided a hole 21 of an inner diameter through which the sleeve 17, an outer diameter larger than the hole 21, and said retaining member 2 through the through hole 18a insert the sleeve 18 to be penetrated established, further, the upper end of the partition chamber R 2 of the upper is established the upper lid portion 16c which the holding member 2 is penetrated through the through hole in the center thereof openably
While the sleeve 17, 18 is to be mounted removably, the partition wall chamber R 1 of the lower provided with a gas inlet 19, said above the partition wall chamber R 2 is provided a gas outlet 20 the supplies the gas to the partition wall chamber R 1 of the lower from the gas supply port 19, so that the exhaust gas of the gas discharge port 20 and the partition wall chamber R 2 from the gap of the through hole upper of the upper lid portion 16c A dehydration sintering furnace for an optical fiber preform, characterized in that:

そして、さらに、も一つは、前記下側の隔壁室R1内に
供給するガス圧を前記マッフル３内の内圧より小さくす
る一方、当該下側の隔壁室R1内のガス圧より前記上側の
隔壁室R2内の内圧を小さくなるようにして、前記マッフ
ル３、下側の隔壁室R1及び上側の隔壁室R2間に圧力傾斜
ができるようにしたことを特徴とする請求項１記載の光
ファイバ母材の脱水焼結炉にある。Then, further, one may, while smaller than the internal pressure in the muffle 3 gas pressure supplied to the lower side of the partition wall chamber R 1, the upper side of the gas pressure of the lower side of the partition wall chamber R 1 so as to become smaller the internal pressure of the partition chamber R 2 of the muffle 3, claim 1, characterized in that to allow a pressure gradient on the lower side of the partition wall chamber R 1 and the upper between barrier ribs chamber R 2 The dehydration sintering furnace for an optical fiber preform described above.

＜作用＞ 上記の構成により、２個のスリーブ17,18は、上蓋部1
6cを開閉することによって、各隔壁室R1,R2の底壁16a,1
6bに着脱可能に設置することができ、マッフル３内の気
密性の保持が十分に行われ、また、下側の隔壁室R1への
ガス供給と上側の隔壁室R2からのガス排気によって、マ
ッフル内圧のコントールが極めて容易にできる。<Operation> With the above configuration, the two sleeves 17 and 18 are
By opening and closing the 6c, the respective partition walls chambers R 1, R 2 of the bottom wall 16a, 1
Removably can be installed in 6b, muffle 3 in the airtightness of the holding is sufficiently performed, also by the gas exhaust from the gas supply and the upper partition wall chamber R 2 of the lower side to the partition wall chamber R 1 Control of the internal pressure of the muffle can be made extremely easy.

＜実施例＞ 第１図〜第２図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。<Embodiment> Figs. 1 and 2 show an embodiment of a dehydration sintering furnace for an optical fiber preform according to the present invention.

本実施例では、蓋16の構造を２重構造（２段構造）と
し、その上下に２つの隔壁室R1,R2を作り、各室R1,R2の
底壁16a,16bには２個のスリーブ17,18を挿入、設置させ
てあり、また、下段の隔壁室R1にはガス供給口19を、上
段の隔壁室R2にはガス排出口20を夫々形成してある。な
お、上記従来のものと同一部分には同一符号を付してあ
る。In this embodiment, the structure of the lid 16 is a double structure (two-stage structure), vertically create two partition walls chamber R 1, R 2 thereof, each chamber R 1, R 2 of the bottom wall 16a, the 16b insert two sleeves 17 and 18, Yes so installed, also in the lower part of the partition wall chamber R 1 to the gas supply port 19, the upper partition wall chamber R 2 are then respectively form a gas discharge port 20. The same parts as those of the above-mentioned conventional one are denoted by the same reference numerals.

上記スリーブ17,18は、例えば石英ガラス等で作り、
夫々十分な厚さとし、また、上記蓋16の各隔壁室R1,R2
への出し入れは、例えば上端の上蓋部16cを開閉して行
う。そのため、下段の隔壁室R1に設置されるスリーブ17
は、その外径の大きさを小さめに抑え、上段の底壁（中
底）16bに開けた大きめの穴21を通るようにする。一
方、上段の隔壁室R2に設置されるスリーブ18は、少なく
とも上記穴21よりその外径を大きくして、上段底壁16b
に載るようにする。The sleeves 17, 18 are made of, for example, quartz glass or the like,
Each of the partition walls R 1 , R 2 of the lid 16 has a sufficient thickness.
For example, opening and closing of the upper lid 16c is performed by opening and closing the upper lid 16c. Therefore, sleeve 17 is placed in the lower part of the partition wall chamber R 1
Is designed to keep its outer diameter small and pass through a large hole 21 formed in the bottom wall (middle bottom) 16b of the upper stage. On the other hand, the sleeve 18 is placed upper in the partition chamber R 2, a larger outer diameter than at least the hole 21, the upper base wall 16b
So that

そして、各スリーブ17,18の中央の貫通穴17a,18aは、
夫々光ファイバ母材１の保持材２である、例えばガラス
棒が、極めて小さい最適の隙間をもって装着される穴と
する。また、必要に応じて、種々の寸法の保持材２に対
応できるように、幾つかの異なる穴径を有するスリーブ
17,18を用意しておくとよい。And the through holes 17a, 18a at the center of each sleeve 17, 18 are
Each of the holding members 2 of the optical fiber preform 1, for example, a glass rod is a hole to be mounted with an extremely small optimum gap. Further, if necessary, a sleeve having several different hole diameters so as to be able to accommodate the holding member 2 having various dimensions.
17,18 should be prepared.

従って、本焼結炉の場合、駆動時、各スリーブ17,18
と保持材２の隙間は十分に小さく、かつスリーブ17,18
自体の厚さも厚く、隙間巾が大きいため、この部分での
気密は、十分確保される。このため、マッフル３内に供
給されるガス量が少なくてもよく、マッフル内圧のコン
トロールがその分し易くなる。Therefore, in the case of this sintering furnace, each sleeve 17, 18
And the gap between the holding member 2 and the sleeve 17, 18
Since the thickness itself is large and the gap width is large, airtightness in this portion is sufficiently ensured. For this reason, the amount of gas supplied into the muffle 3 may be small, and the control of the muffle internal pressure becomes easier.

また、光ファイバ母材１の保持材２に多少の振動等が
あっても、各スリーブ17,18が当該保持材２と同一の動
きをするため、スリーブ17,18の貫通穴17a,18aとの隙間
には変化はなく、さらに、蓋16の底壁16a,16bとの隙間2
2,23もスリーブ17,18自体の重さにより常時密着される
ため、やはり高い気密性が保たれる。Further, even if the holding member 2 of the optical fiber preform 1 has some vibration or the like, since the sleeves 17 and 18 move in the same manner as the holding member 2, the through holes 17a and 18a of the sleeves 17 and 18 have There is no change in the gap between the bottom wall 16a and the bottom wall 16a, 16b of the lid 16.
Since the sleeves 2 and 23 are always in close contact with each other due to the weight of the sleeves 17 and 18 themselves, high airtightness is also maintained.

また、蓋16のガス供給口19から、適量のヘリウム量の
ガスを供給することにより、下段の隔壁室R1内には当該
ガスが充填されるため、マッフル３内および上段の隔壁
室R2に対して、一種のガスバリア層が形成されるため、
外部空気等のマッフル３内への流入を効果的に防止する
ことができる。さらに、また、マッフル３内の充填ガス
に対しても、漏れ抑止効果が期待できる。Further, the gas supply port 19 of the lid 16, by supplying an appropriate amount of helium amount of gas, since the gas is filled in the lower part of the partition wall chamber R 1, the muffle 3 and the upper partition wall chamber R 2 In contrast, a kind of gas barrier layer is formed,
Inflow of external air and the like into the muffle 3 can be effectively prevented. Further, a leakage suppressing effect can be expected for the filling gas in the muffle 3.

この下段の隔壁室R1内に充填されたガスは上段の隔壁
室R2に適宜漏れていくため、この洩れたガスは、当該隔
壁室R2のガス排気口20から外部に取り出す。Gas is filled in the lower part of the partition wall chamber R 1 for gradually leaked appropriate upper partition wall chamber R 2, the leaked gas is removed from the septum chamber R 2 of the gas outlet 20 to the outside.

この際、下段の隔壁室R1内に供給するガス圧をマッフ
ル３内の内圧より小さくし、また、この下段の隔壁室R1
の内圧より上段の隔壁室R2の内圧を小さくするように、
各内圧間に適当な圧力傾斜を設ければ、理想的なマッフ
ルの内圧コントロールが可能となる。At this time, the gas pressure supplied to the lower part of the partition wall chamber R 1 smaller than the internal pressure in the muffle 3, also in the lower partition wall chamber R 1
Of so as to reduce the upper pressure of the partition chamber R 2 from the internal pressure,
If an appropriate pressure gradient is provided between the respective internal pressures, the internal pressure of the ideal muffle can be controlled.

＜発明の効果＞ 本発明に係る光ファイバ母材の脱水焼結炉によれば、
次のような効果を得ることができる。<Effect of the Invention> According to the dehydration sintering furnace for the optical fiber preform according to the present invention,
The following effects can be obtained.

（１）．蓋16を２重構造とし、その上下に２つの隔壁室
R1,R2を設け、これらの隔壁室R1,R2の底壁16a,16b部分
に、光ファイバ母材１の保持材２が極めて小さい最適の
隙間をもって貫通される２個のスリーブ17,18を挿入、
設置してあるため、極めて良好な気密性が得られ、高精
度でのマッフル内圧のコントロールができる。(1). The lid 16 has a double structure with two partition chambers above and below it.
R 1 and R 2 are provided, and two sleeves 17 through which the holding material 2 of the optical fiber preform 1 is penetrated through the bottom walls 16 a and 16 b of these partition chambers R 1 and R 2 with an extremely small optimum gap. , 18,
Because it is installed, extremely good airtightness is obtained, and the muffle internal pressure can be controlled with high accuracy.

（２）．また、下側の隔壁室R1の底壁16aに設置される
スリーブ17の外径は、上側の隔壁室R2の底壁16bに設け
た穴21の内径より小さく、また、上側の隔壁室R2の底壁
16bに設置されるスリーブ18の外径は、上記上側の隔壁
室R2の底壁16bに設けた穴21の内径より大きいため、上
端の上蓋部16cを開いた状態で、スリーブ17、スリーブ1
8の順に着脱自在に取り付けることができ、良好な使い
勝手が得られる。(2). Further, the outer diameter of the sleeve 17 to be installed on the lower side of the partition wall chamber R 1 of the bottom wall 16a, smaller than the inner diameter of the hole 21 provided on the upper side of the bottom wall 16b of the partition chamber R 2, also, the upper partition wall chamber R 2 bottom wall
Since the outer diameter of the sleeve 18 to be installed in 16b is larger than the inner diameter of the hole 21 provided in the bottom wall 16b of the upper partition wall chamber R 2, with open upper lid portion 16c of the upper end, the sleeve 17, the sleeve 1
It can be attached detachably in the order of 8, and good usability is obtained.

（３）．そこで、予め貫通穴17a,18aの寸法の異なるス
リーブ17,18を多数用意しておけば、いろいろな寸法の
光ファイバ母材１の保持材２に迅速に対応することがで
きる。(3). Therefore, if a large number of sleeves 17 and 18 having different dimensions of the through holes 17a and 18a are prepared in advance, it is possible to quickly respond to the holding members 2 of the optical fiber preform 1 having various dimensions.

（４）．このようなスリーブ17,18の高気密性保持機能
により、ガス供給系４の使用ガス量を大幅に節約するこ
とができる。(4). With such a function of maintaining high airtightness of the sleeves 17 and 18, the amount of gas used in the gas supply system 4 can be greatly reduced.

（５）．上記のように蓋16を隔壁室R1,R2を有する構造
とし、その中にスリーブ17,18を設置し、かつ、下側の
隔壁室R1にはガス供給口19からガスを供給すると共に、
上側の隔壁室R2内のガスをガス排出口20及び上蓋部16c
の貫通穴の隙間から排気するようにしてあるため、一種
のガスバリア層が形成されて、より良好なマッフル３内
の気密性保持機能が得られると同時に、外部空気等の流
入阻止機能も得られる。(5). As described above, the lid 16 has a structure having the partition walls R 1 and R 2 , the sleeves 17 and 18 are installed therein, and gas is supplied from the gas supply port 19 to the lower partition wall R 1. Along with
Upper partition wall chamber R 2 in the gas of the gas discharge port 20 and the upper lid portion 16c
Since the gas is exhausted from the gap between the through holes, a kind of gas barrier layer is formed, and a better airtightness maintaining function in the muffle 3 can be obtained, and at the same time, a function of preventing inflow of external air and the like can be obtained. .

（６）．さらに、上記下側の隔壁室R1へのガス供給と上
側の隔壁室R2からのガス排出において、下側の隔壁室R1
内のガス圧をマッフル３内の内圧より小さくする一方、
下側の隔壁室R1内のガス圧より上側の隔壁室R2内の内圧
を小さくなるようにして、マッフル３、下側の隔壁室R1
及び上側の隔壁室R2間に圧力傾斜ができるようにすれ
ば、より一層優れたガスバリア層が形成され、略理想的
なマッフル内圧のコントロールができる。(6). Further, the gas discharge from the gas supply and the upper partition wall chamber R 2 to the partition wall chamber R 1 of the lower, the lower partition chamber R 1
While reducing the gas pressure inside the muffle 3
So as to become smaller the internal pressure of the upper partition wall chamber R 2 from the gas pressure of the lower side of the partition wall chamber R 1, the muffle 3, the lower partition chamber R 1
And if so it is pressure gradient between the upper side of the partition wall chamber R 2, a more is more excellent gas barrier layer is formed, it is controlled substantially ideal muffle pressure.

（７）．このような結果として、昨今、光ファイバに要
求されている高い水準の品質を得ることができる。(7). As a result, it is possible to obtain a high level of quality recently required for optical fibers.

【図面の簡単な説明】[Brief description of the drawings]

第１図は本発明に係る光ファイバ母材の脱水焼結炉の一
実施例を示した概略縦断面図、第２図は第１図の要部を
示した部分拡大図、第３図は従来の光ファイバ母材の脱
水焼結炉の一例を示した概略縦断面図である。 図中、 １……光ファイバ母材、 ２……保持材、 ３……マッフル、 ４……ガス供給系、 ５……加熱部、 16……蓋、 16a……下側の隔壁室の底壁、 16b……上側の隔壁室の底壁、 16c……上蓋部、 17,18……スリーブ、 19……ガス供給口、 20……ガス排気口、 21……下側の隔壁室の底壁の穴、 R1,R2……隔壁室、FIG. 1 is a schematic longitudinal sectional view showing an embodiment of a dehydration sintering furnace for an optical fiber preform according to the present invention, FIG. 2 is a partially enlarged view showing a main part of FIG. 1, and FIG. FIG. 5 is a schematic longitudinal sectional view showing an example of a conventional optical fiber preform dehydration sintering furnace. In the figure, 1 ... optical fiber preform, 2 ... holding material, 3 ... muffle, 4 ... gas supply system, 5 ... heating unit, 16 ... lid, 16a ... bottom of lower partition wall chamber Wall, 16b: Bottom wall of upper partition chamber, 16c: Upper lid, 17,18 ... Sleeve, 19 ... Gas supply port, 20 ... Gas exhaust port, 21 ... Bottom of lower partition chamber Holes in the wall, R 1 , R 2 ...

───────────────────────────────────────────────────── フロントページの続き (56)参考文献 実開 昭63−24236（ＪＰ，Ｕ) 実開 昭64−45134（ＪＰ，Ｕ) (58)調査した分野(Int.Cl.6，ＤＢ名) C03B 37/014──────────────────────────────────────────────────続 き Continuation of the front page (56) References Japanese Utility Model Sho 63-24236 (JP, U) Japanese Utility Model Sho 64-45134 (JP, U) (58) Fields surveyed (Int.Cl. 6 , DB name) C03B 37/014

Claims (2)

(57)【特許請求の範囲】(57) [Claims] 【請求項１】保持材２により懸架された光ファイバ母材
１が収容されるマッフル３と、該マッフル３中に脱水剤
を含むガスを供給するガス供給系４と、前記マッフル３
内の光ファイバ母材１を加熱する加熱部５と、前記マッ
フル３上部に取り付けられ、前記保持材２が貫通される
蓋16とを備えた光ファイバ母材の脱水焼結炉において、
前記蓋16を２重構造とし、その上下に２つの隔壁室R1,R
2を設け、下側の隔壁室R1の底壁16aにはその貫通穴17a
を通じて前記保持材２が貫通されるスリーブ17を挿入、
設置する一方、上側の隔壁室R2の底壁16bには前記スリ
ーブ17が通る内径の穴21を設けると共に、当該穴21より
その外径が大きく、かつその貫通穴18aを通じて前記保
持材２が貫通されるスリーブ18を挿入、設置し、さら
に、前記上側の隔壁室R2の上端にはその中央の貫通穴を
通じて前記保持材２が貫通される上蓋部16cを開閉自在
に設置して、前記スリーブ17,18が着脱自在に取り付け
られるようにする一方、前記下側の隔壁室R1にはガス供
給口19を設けると共に、前記上側の隔壁室R2にはガス排
出口20を設けて、前記ガス供給口19から下側の隔壁室R1
にガスを供給すると共に、前記ガス排出口20及び前記上
蓋部16cの貫通穴の隙間から上側の隔壁室R2内のガスを
排気するようにしたことを特徴とする光ファイバ母材の
脱水焼結炉。A muffle for accommodating an optical fiber preform suspended by a holding material, a gas supply system for supplying a gas containing a dehydrating agent into the muffle;
In a dehydration and sintering furnace for an optical fiber preform, comprising: a heating unit 5 for heating the optical fiber preform 1 therein; and a lid 16 attached to the upper portion of the muffle 3 and through which the holding material 2 passes.
The lid 16 has a double structure, and two partition walls R 1 , R
2 is provided, on the lower side of the partition wall chamber R 1 of the bottom wall 16a thereof through hole 17a
Insert the sleeve 17 through which the holding material 2 passes,
While installation, with the upper side of the bottom wall 16b of the partition chamber R 2 is provided a hole 21 of an inner diameter through which the sleeve 17, an outer diameter larger than the hole 21, and said retaining member 2 through the through hole 18a insert the sleeve 18 to be penetrated established, further, the upper end of the partition chamber R 2 of the upper is established the upper lid portion 16c which the holding member 2 is penetrated through the through hole in the center thereof openably said while the sleeve 17, 18 is to be mounted removably, said the lower side of the partition wall chamber R 1 provided with a gas inlet 19, the partition wall chamber R 2 of the upper is provided a gas outlet 20, From the gas supply port 19 to the lower partition chamber R 1
The supplies of gas, the gas outlet 20 and dehydrated sintered optical fiber preform, characterized in that it has from the gap of the through hole of the upper cover portion 16c so as to exhaust the gas in the upper partition wall chamber R 2 Furnace. 【請求項２】前記下側の隔壁室R1内に供給するガス圧を
前記マッフル３内の内圧より小さくする一方、当該下側
の隔壁室R1内のガス圧より前記上側の隔壁室R2内の内圧
を小さくなるようにして、前記マッフル３、下側の隔壁
室R1及び上側の隔壁室R2間に圧力傾斜ができるようにし
たことを特徴とする請求項１記載の光ファイバ母材の脱
水焼結炉。Wherein said one of the gas pressure supplied to the lower side of the partition wall chamber R 1 smaller than the internal pressure in the muffle 3, the upper partition wall chamber R from the gas pressure of the lower side of the partition wall chamber R 1 so as to become smaller the internal pressure in 2, the muffle 3, the optical fiber according to claim 1, characterized in that to allow a pressure gradient on the lower side of the partition wall chamber R 1 and the upper between barrier ribs chamber R 2 Dehydration sintering furnace for base material.
JP1033454A 1989-02-13 1989-02-13 Dehydration sintering furnace for optical fiber preform Expired - Fee Related JP2791380B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP1033454A JP2791380B2 (en) 1989-02-13 1989-02-13 Dehydration sintering furnace for optical fiber preform

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1033454A JP2791380B2 (en) 1989-02-13 1989-02-13 Dehydration sintering furnace for optical fiber preform

Publications (2)

Publication Number Publication Date
JPH02212325A JPH02212325A (en) 1990-08-23
JP2791380B2 true JP2791380B2 (en) 1998-08-27

Family

ID=12386984

Family Applications (1)

Application Number Title Priority Date Filing Date
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Country Status (1)

Country Link
JP (1) JP2791380B2 (en)

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Publication number Priority date Publication date Assignee Title
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
JP4737031B2 (en) * 2006-10-26 2011-07-27 住友電気工業株式会社 Glass base material manufacturing method and manufacturing apparatus
JP6539609B2 (en) * 2015-03-24 2019-07-03 信越化学工業株式会社 Sintering apparatus and sintering method
JP6621388B2 (en) * 2016-08-02 2019-12-18 信越化学工業株式会社 Sintering equipment
CN108585471B (en) * 2018-06-25 2021-08-17 长飞光纤光缆股份有限公司 Dehydration sintering device and method for low-water-peak optical fiber preform
CN112624600B (en) * 2021-01-12 2023-06-23 江苏法尔胜光子有限公司 Sintering furnace exhaust hood for preparing optical fiber preform and on-line adjusting method of exhaust pressure

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US4609671A (en) * 1985-06-27 1986-09-02 E. R. Squibb & Sons, Inc. 5,6-epoxy-7-oxabicycloheptane substituted amino prostaglandin analogs useful in the treatment of thrombotic disease
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Also Published As

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