JPH0211529B2 - - Google Patents
Info
- Publication number
- JPH0211529B2 JPH0211529B2 JP1203085A JP1203085A JPH0211529B2 JP H0211529 B2 JPH0211529 B2 JP H0211529B2 JP 1203085 A JP1203085 A JP 1203085A JP 1203085 A JP1203085 A JP 1203085A JP H0211529 B2 JPH0211529 B2 JP H0211529B2
- Authority
- JP
- Japan
- Prior art keywords
- furnace
- furnace body
- sealing material
- core tube
- sealing
- 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 - Lifetime
Links
- 239000003566 sealing material Substances 0.000 claims description 41
- 238000010438 heat treatment Methods 0.000 claims description 29
- 239000007789 gas Substances 0.000 claims description 22
- 239000000463 material Substances 0.000 claims description 22
- 239000011261 inert gas Substances 0.000 claims description 21
- 239000013307 optical fiber Substances 0.000 claims description 16
- 238000007789 sealing Methods 0.000 claims description 11
- 239000011810 insulating material Substances 0.000 claims description 10
- 238000000034 method Methods 0.000 claims description 9
- 238000005192 partition Methods 0.000 claims description 8
- 239000000919 ceramic Substances 0.000 claims description 6
- 239000000835 fiber Substances 0.000 claims description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 7
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 6
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 6
- 238000007796 conventional method Methods 0.000 description 4
- 230000003647 oxidation Effects 0.000 description 4
- 238000007254 oxidation reaction Methods 0.000 description 4
- 239000010453 quartz Substances 0.000 description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 4
- 229910052786 argon Inorganic materials 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 238000010030 laminating Methods 0.000 description 2
- 238000003825 pressing Methods 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- 230000005856 abnormality Effects 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 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
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)
Description
【発明の詳細な説明】
〔技術分野〕
本発明は、光フアイバ母材（多孔質母材）の脱
水、焼結および透明化を行うための抵抗加熱炉の
シール方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for sealing a resistance heating furnace for dehydrating, sintering, and making transparent an optical fiber base material (porous base material).
光フアイバ母材（以下多孔質母材という）を脱
水、焼結および透明化して光フアイバプリフオー
ムを製造するため、従来は第２図および第３図に
示すような抵抗加熱炉が使用されている。これは
光フアイバ母材が挿入され加熱される炉芯管１
と、該炉芯管１のまわりに内側から順に抵抗型の
発熱体２、断熱材３および該断熱材３を覆う炉体
４とが同軸状に設けられ、かつ前記炉芯管１は通
常炉体４よりも長く、炉体４を貫通する形で炉体
４の炉体開口部５から突出するように構成されて
いるものである。ここで、前記発熱体２や断熱材
３の部品の材料としてはカーボン、特に黒鉛を成
形したものが多く使用され、また前記炉体４は金
属製で通常は水により冷却されている。ところ
で、カーボンや黒鉛を成形してなる前記発熱体２
や断熱材３の部品は、空気中では一般に400℃を
超えると酸化によつて消失してしまう。それ故、
400℃をはるかに超え、千数百℃に達する炉体４
内での前記部品の酸化を防止すべく、通常炉体４
内は窒素やアルゴン等の不活性ガスで満たされ、
かつ外気の炉体４内への侵入を防ぐべく炉芯管１
と炉体４との隙間、すなわち、炉体開口部５はシ
ールされている。
Conventionally, a resistance heating furnace as shown in Figs. 2 and 3 has been used to produce optical fiber preforms by dehydrating, sintering, and making transparent optical fiber base materials (hereinafter referred to as porous base materials). There is. This is the furnace core tube 1 into which the optical fiber base material is inserted and heated.
A resistance-type heating element 2, a heat insulating material 3, and a furnace body 4 covering the heat insulating material 3 are coaxially provided around the furnace core tube 1 in order from the inside, and the furnace core tube 1 is arranged in a normal furnace. It is longer than the furnace body 4 and is configured to protrude from the furnace body opening 5 of the furnace body 4 so as to penetrate through the furnace body 4 . Here, the heating element 2 and the heat insulating material 3 are often made of molded carbon, especially graphite, and the furnace body 4 is made of metal and is usually cooled with water. By the way, the heating element 2 is formed by molding carbon or graphite.
In general, the heat insulating material 3 components disappear due to oxidation when the temperature exceeds 400°C in the air. Therefore,
Furnace body 4 reaching temperatures far exceeding 400℃ and reaching over 1,000℃
In order to prevent oxidation of the parts within the furnace body 4,
The inside is filled with inert gas such as nitrogen or argon,
In order to prevent outside air from entering the furnace body 4, the furnace core tube 1 is
The gap between the furnace body 4 and the furnace body opening 5 is sealed.
ところで従来行われている前記炉体開口部５の
シール方法としては、第２図の如く、ガス注入管
１４，１５，１６から窒素等の不活性ガスを注入
し、炉体４内に不活性ガスによるエアカーテンを
作る方法と、第３図の如く、炉体開口部５，５を
適当な耐熱性のシール部材７，７で塞ぎ、炉体４
内を外気から遮断する方法がある。しかし、前者
においては炉体４の隙間全域にわたつて、完全に
不活性ガスによるエアカーテンを形成するために
は注入すべき不活性ガスの量は非常に大きくな
り、不活性ガスの無駄は免れない。さらに後者の
おいてはシール部材７，７として柔軟性と耐熱性
に優れ、かつ緊密にシールできる材料がない。耐
熱性に優れたものとしては、例えば、セラミツク
フアイバ等があるが、単純にセラミツクフアイバ
を使用するだけでは充填密度を高くできないため
気密性に問題がある。それ故、前記セラミツクフ
アイバをシール部材７として使用する場合は、炉
体４内の不活性ガスの圧力を高くしなければ外気
の侵入を完全に防止できない。ところが、一般的
に石英からなる炉芯管１も炉体４内の千数百℃と
いう高温で軟化しているため、炉体４内の不活性
ガスの圧力を高くすると、この圧力で前記石英製
の炉芯管１が収縮し変形してしまう。 By the way, as a conventional method of sealing the furnace body opening 5, as shown in FIG. As shown in FIG. 3, the furnace body openings 5, 5 are closed with appropriate heat-resistant seal members 7, 7,
There are ways to isolate the inside from the outside air. However, in the former case, the amount of inert gas that must be injected is extremely large in order to completely form an air curtain of inert gas over the entire gap in the furnace body 4, and the inert gas is not wasted. do not have. Furthermore, in the latter case, there is no material for the sealing members 7, 7 that has excellent flexibility and heat resistance and can be tightly sealed. Examples of materials with excellent heat resistance include ceramic fibers, but simply using ceramic fibers does not increase the packing density, resulting in problems with airtightness. Therefore, when the ceramic fiber is used as the sealing member 7, the intrusion of outside air cannot be completely prevented unless the pressure of the inert gas within the furnace body 4 is increased. However, since the furnace core tube 1, which is generally made of quartz, is also softened at the high temperature of several thousand degrees Celsius inside the furnace body 4, when the pressure of the inert gas inside the furnace body 4 is increased, this pressure causes the quartz to melt. The furnace core tube 1 made of aluminum will shrink and become deformed.
以上の如く、前記第１図、第２図に示す従来の
方法にあつてはいずれの場合もそれぞれ問題があ
つた。 As described above, the conventional methods shown in FIGS. 1 and 2 have their own problems.
前記問題に鑑み本発明の目的は、炉体内のカー
ボン製部品の酸化防止に加え、不活性ガスの使用
量をできるだけ少なくとどめ、しかも炉芯管の材
質如何によらず該炉芯管を変形に至らしめること
なく、多孔質母材を加熱炉中で高温処理できる光
フアイバ母材用抵抗加熱炉のシール方法を提供す
ることにある。
In view of the above problems, it is an object of the present invention to prevent oxidation of carbon parts in the furnace body, to minimize the amount of inert gas used, and to prevent deformation of the furnace core tube regardless of the material of the furnace core tube. It is an object of the present invention to provide a sealing method for a resistance heating furnace for an optical fiber base material, which allows a porous base material to be subjected to high-temperature treatment in a heating furnace without causing any damage to the porous base material.
前記目的を達成すべく本発明の光フアイバ母材
用抵抗加熱炉のシール方法は、光フアイバ母材が
挿入される炉芯管と、該炉芯管のまわりに内側か
ら順に抵抗発熱体、断熱材および該断熱材を覆う
炉体とが同軸状に設けられ、前記炉芯管が前記炉
体の開口部から突出している光フアイバ母材を加
熱する加熱炉において、前記炉体の開口部と炉芯
管との隙間を耐熱性のシール材Ａで塞ぎ、該耐熱
性のシール材Ａを挟んで前記炉体の内側と外側と
を分離すると共に、前記シール材Ａの外側に前記
シール材Ａを一方の隔壁とし他方の隔壁をシール
材Ｂとするガス室を設け、前記炉体の内側と前記
ガス室とに不活性ガスを流し、前記炉体内および
ガス室の不活性ガスの圧力を大気圧より高くし、
かつ炉体内よりガス室内の圧力を高く保つように
したことを特徴とするものである。
In order to achieve the above object, the present invention provides a sealing method for a resistance heating furnace for optical fiber preforms, which includes a furnace core tube into which an optical fiber preform is inserted, and a resistance heating element and a heat insulator installed around the furnace core tube in order from the inside. In a heating furnace for heating an optical fiber base material, a heating material and a furnace body covering the heat insulating material are provided coaxially, and the furnace core tube protrudes from an opening of the furnace body. The gap with the furnace core tube is closed with a heat-resistant sealing material A, and the inside and outside of the furnace body are separated by sandwiching the heat-resistant sealing material A, and the sealing material A is placed on the outside of the sealing material A. A gas chamber is provided with B as one partition wall and sealing material B on the other partition wall, and an inert gas is flowed into the inside of the furnace body and the gas chamber to increase the pressure of the inert gas in the furnace body and the gas chamber. higher than atmospheric pressure,
It is also characterized in that the pressure in the gas chamber is maintained higher than that in the furnace body.
本発明の実施例を図を参照して詳細に説明す
る。第１図は本発明の光フアイバ母材用抵抗加熱
炉のシール方法の一実施例を示している。本図が
示すように本発明の方法は、光フアイバ母材が挿
入される、例えば石英製の炉芯管１と、該炉芯管
１のまわりに内側から順に抵抗型の発熱体２、断
熱材３および該断熱材３を覆う炉体４とが同軸状
に設けられ、前記炉芯管１が前記炉体４の炉体開
口部５から突出している光フアイバ母材を加熱す
る加熱炉において、前記炉体４の炉体開口部５
を、例えばセラミツクフアイバブランケツトを輪
切りにしたものを数枚積層させてなる耐熱性のシ
ール材Ａ８で塞ぎ、該耐熱性のシール材Ａ８を挟
んで前記炉体４の内側と外側とを分離すると共
に、前記シール材Ａ８の外側にこのシール材Ａ８
を一方の隔壁とし、かつ窒素あるいはアルゴン等
の不活性ガスが注入されるガス室１７を設ける。
ここで前記ガス室１７を設けるために、前記シー
ル材Ａ８と、該シール材Ａ８と同様にセラミツク
フアイバブランケツトを輪切りにしたものを数枚
積層せしめてなるシール材Ｂ１８とをリング１３
にて隔て、かつこれらシール材Ａ８、シール材Ｂ
１８およびリング１３を一端が前記炉体開口部５
に接続されているシール箱９に内包させる。すな
わち、前記シール材Ａ８を炉体４とガス室１７と
の隔壁とし、かつシール材Ｂ１８をガス室１７と
外気の隔壁とする。尚、符号２０はリング１３の
外側から流入する不活性ガスをリング１３の内側
に導くための連通孔であり、符号１０，１１，１
２は前記シール材Ａ８、シール材Ｂ１８にリング
１３を介して圧力を加えるためのボルト、ナツト
をふくむシール押えで、このようにしてシール材
Ａ８、シール材Ｂ１８を圧縮することで該シール
材Ａ８、シール材Ｂ１８Ａを圧密（圧力を加えて
密度高くすること）し、これらシール材Ａ８、シ
ール材Ｂ１８を通過するガス量を少なくする。す
ならち、シール材内の隙間を小さくせしめる。こ
のようにしてなる前記炉体４の内側と前記ガス室
１７とにガス注入口１４，１５，１６から、例え
ばアルゴンや窒素等の不活性ガスを送り込み、か
つ炉体４内の圧力を炉芯管１に変形をもたらさな
い程度の低い値に止めながら、ガス室１７の圧力
は外気の炉体４内への侵入を防止するのに充分な
大きさの値に調整する。尚、第１図は抵抗加熱炉
の下部の構造のみ示しているが、上部についても
同様の構造である。
Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an embodiment of the sealing method for a resistance heating furnace for optical fiber base material according to the present invention. As shown in this figure, the method of the present invention consists of a furnace core tube 1 made of, for example, quartz, into which an optical fiber base material is inserted, a resistance-type heating element 2, a heat-insulating In a heating furnace for heating an optical fiber base material, a material 3 and a furnace body 4 covering the heat insulating material 3 are provided coaxially, and the furnace core tube 1 protrudes from a furnace body opening 5 of the furnace body 4. , the furnace body opening 5 of the furnace body 4
, for example, with a heat-resistant sealing material A8 made by laminating several slices of ceramic fiber blanket, and separating the inside and outside of the furnace body 4 by sandwiching the heat-resistant sealing material A8. At the same time, this sealing material A8 is placed on the outside of the sealing material A8.
is used as one partition wall, and a gas chamber 17 into which an inert gas such as nitrogen or argon is injected is provided.
Here, in order to provide the gas chamber 17, the sealing material A8 and a sealing material B18, which is made by laminating several slices of ceramic fiber blankets similar to the sealing material A8, are attached to the ring 13.
and these sealing material A8, sealing material B
18 and ring 13, one end of which is connected to the furnace body opening 5.
It is enclosed in a seal box 9 connected to. That is, the sealing material A8 is used as a partition between the furnace body 4 and the gas chamber 17, and the sealing material B18 is used as a partition between the gas chamber 17 and the outside air. Note that reference numeral 20 is a communication hole for guiding inert gas flowing from the outside of the ring 13 into the inside of the ring 13, and reference numerals 10, 11, 1
2 is a seal presser including a bolt and a nut for applying pressure to the sealing material A8 and sealing material B18 through the ring 13, and by compressing the sealing material A8 and sealing material B18 in this way, the sealing material A8 is compressed. , the sealing material B18A is compressed (applying pressure to increase its density) to reduce the amount of gas passing through these sealing materials A8 and B18. In other words, the gap within the sealing material is made smaller. Inert gas, such as argon or nitrogen, is fed into the interior of the furnace body 4 and the gas chamber 17 from the gas inlets 14, 15, 16, and the pressure inside the furnace body 4 is reduced to the furnace core. The pressure in the gas chamber 17 is adjusted to a value large enough to prevent outside air from entering the furnace body 4, while keeping the pressure low enough not to cause deformation of the tube 1. Although FIG. 1 only shows the structure of the lower part of the resistance heating furnace, the structure of the upper part is also similar.
このようにしてなる本発明にあつては、ガス室
１７に注入された不活性ガスは、該ガス室１７か
らシール材Ａ８の圧密されてわずかしかない空隙
を通して炉体４内へ少しづつ流れ、同様に圧密さ
れたシール材Ｂ１８のわずかな空隙を通して外気
へと流れ、外気の炉体４内への侵入を防止する。
具体的には第１図に示す実施例において、炉体４
内の不活性ガスの圧力を大気圧より５mmH2O高
くし、かつガス室１７内の圧力を大気圧より30mm
H2O高くした。その結果、石英製の炉芯管１を
変形させることもなく、かつまた炉体４内の発熱
体２および断熱材３等の部品でカーボン製のもの
に全く損傷を与えることなく抵抗加熱炉の運転を
行うことができた。同時に、シール材Ａ８、シー
ル材Ｂ１８が圧密されているため、これらシール
材を通過する不活性ガスの量が少なくなり、その
結果不活性ガスの消費量が大幅に減少した。 In the present invention constructed in this manner, the inert gas injected into the gas chamber 17 gradually flows from the gas chamber 17 into the furnace body 4 through the compacted and narrow gap of the sealing material A8, Similarly, it flows into the outside air through a small gap in the sealed sealing material B18, and prevents outside air from entering the furnace body 4.
Specifically, in the embodiment shown in FIG.
The pressure of the inert gas in the gas chamber 17 is raised to 5 mmH 2 O higher than atmospheric pressure, and the pressure in the gas chamber 17 is raised to 30 mm higher than atmospheric pressure.
H2O was elevated. As a result, the resistance heating furnace can be heated without deforming the furnace core tube 1 made of quartz, and without causing any damage to parts such as the heating element 2 and the heat insulating material 3 in the furnace body 4, which are made of carbon. I was able to drive. At the same time, since the sealing material A8 and the sealing material B18 are compressed, the amount of inert gas passing through these sealing materials is reduced, and as a result, the amount of inert gas consumed is significantly reduced.
尚、前記実施例においては炉芯管１が炉体４を
貫通する構造のものについて述べたが、炉芯管１
が炉体４に対して一方のみ突出している構造のも
の、さらには抵抗加熱炉全体を横型にした構造の
ものについても本発明の方法を適用できることは
いうまでもない。 Incidentally, in the above embodiment, a structure in which the furnace core tube 1 penetrates the furnace body 4 was described, but the furnace core tube 1
Needless to say, the method of the present invention can also be applied to a structure in which only one side of the resistance heating furnace is protruded from the furnace body 4, or a structure in which the entire resistance heating furnace is horizontal.
前述の如く本発明によれば、炉体の外側にガス
室を設け、該ガス室の隔壁を圧密された耐熱性の
シール材で構成したため、炉体内の圧力は低い値
に止めながら、炉体の開口部は高い圧力の不活性
ガスで覆うことができる。しかも、この不活性ガ
スの消費量を従来の方法よりも大幅に減少でき
る。このように、少量の不活性ガスを用いて、炉
芯管に変形等の異常をもたらすことなく、炉体内
のカーボン製部品の酸化を防止しながら、多孔質
母材を加熱炉中で高温処理できる。
As described above, according to the present invention, the gas chamber is provided outside the furnace body, and the partition wall of the gas chamber is made of a compressed heat-resistant sealing material. The opening can be covered with high pressure inert gas. Furthermore, the amount of inert gas consumed can be significantly reduced compared to conventional methods. In this way, by using a small amount of inert gas, the porous base material can be treated at high temperature in a heating furnace without causing abnormalities such as deformation of the furnace core tube and while preventing oxidation of the carbon parts inside the furnace body. can.
第１図は本発明の一実施例を示す一部縦断面
図、第２図、第３図は従来の方法を示す縦断面図
である。
１……炉芯管、２……発熱体、３……断熱材、
４……炉体、５……炉体開口部、８……シール材
Ａ、９……シール箱、１８……シール材Ｂ。
FIG. 1 is a partial longitudinal sectional view showing an embodiment of the present invention, and FIGS. 2 and 3 are longitudinal sectional views showing a conventional method. 1... Furnace core tube, 2... Heating element, 3... Heat insulating material,
4...Furnace body, 5...Furnace body opening, 8...Sealing material A, 9...Sealing box, 18...Sealing material B.
Claims (1)
芯管のまわりに内側から順に抵抗発熱体、断熱材
および該断熱材を覆う炉体とが同軸状に設けら
れ、前記炉芯管が前記炉体の開口部から突出して
いる光フアイバ母材を加熱する抵抗加熱炉におい
て、前記炉体の開口部と炉芯管との隙間を耐熱性
のシール材Ａで塞ぎ、該耐熱性のシール材Ａを挟
んで前記炉体の内側と外側とを分離すると共に、
前記シール材Ａの外側に前記シール材Ａを一方の
隔壁とし他方の隔壁をシール材Ｂとするガス室を
設け、前記炉体の内側と前記ガス室とに不活性ガ
スを流し、前記炉体内およびガス室内の不活性ガ
スの圧力を大気圧より高くし、かつ炉体内よりガ
ス室内の圧力を高く保つようにしたことを特徴と
する光フアイバ母材用抵抗加熱炉のシール方法。 ２ 前記耐熱性のシール材Ａおよびシール材Ｂは
セラミツクフアイバからなることを特徴とする特
許請求の範囲第１項記載の光フアイバ母材用抵抗
加熱炉のシール方法。 ３ 前記耐熱性のシール材Ａおよびシール材Ｂは
圧密されていることを特徴とする特許請求の範囲
第１項または第２項記載の光フアイバ母材用抵抗
加熱炉のシール方法。[Scope of Claims] 1. A furnace core tube into which an optical fiber preform is inserted, and a resistance heating element, a heat insulating material, and a furnace body covering the heat insulating material are provided coaxially around the furnace core tube in order from the inside. In a resistance heating furnace for heating an optical fiber base material in which the furnace core tube protrudes from the opening of the furnace body, a gap between the opening of the furnace body and the furnace core tube is filled with a heat-resistant sealing material A. Separating the inside and outside of the furnace body by sandwiching the heat-resistant sealing material A,
A gas chamber is provided outside the sealing material A, and the sealing material A is used as one partition wall, and the other partition wall is used as the sealing material B. An inert gas is caused to flow inside the furnace body and into the gas chamber. and a method for sealing a resistance heating furnace for optical fiber base material, characterized in that the pressure of the inert gas in the gas chamber is made higher than atmospheric pressure, and the pressure in the gas chamber is kept higher than in the furnace body. 2. The sealing method for a resistance heating furnace for optical fiber base material according to claim 1, wherein the heat-resistant sealing material A and the sealing material B are made of ceramic fiber. 3. The method for sealing a resistance heating furnace for optical fiber base material according to claim 1 or 2, wherein the heat-resistant sealing material A and the sealing material B are consolidated.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1203085A JPS61174134A (en) | 1985-01-25 | 1985-01-25 | Sealing method of resistance heating furnace for optical fiber base material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1203085A JPS61174134A (en) | 1985-01-25 | 1985-01-25 | Sealing method of resistance heating furnace for optical fiber base material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61174134A JPS61174134A (en) | 1986-08-05 |
| JPH0211529B2 true JPH0211529B2 (en) | 1990-03-14 |
Family
ID=11794203
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1203085A Granted JPS61174134A (en) | 1985-01-25 | 1985-01-25 | Sealing method of resistance heating furnace for optical fiber base material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61174134A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4973440B2 (en) * | 2007-10-18 | 2012-07-11 | 住友電気工業株式会社 | Glass article heating method and induction furnace |
-
1985
- 1985-01-25 JP JP1203085A patent/JPS61174134A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61174134A (en) | 1986-08-05 |
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| EXPY | Cancellation because of completion of term |