JP2005248339A

JP2005248339A - Carbonizing oven

Info

Publication number: JP2005248339A
Application number: JP2004057093A
Authority: JP
Inventors: Hiroshige Inada; 浩成稲田; Nobuyuki Yamamoto; 伸之山本; Yasuto Tokoro; 靖人所; Toshihiko Nishida; 俊彦西田; Satoshi Nagatsuka; 悟志長束
Original assignee: Mitsubishi Rayon Co Ltd
Current assignee: Mitsubishi Rayon Co Ltd
Priority date: 2004-03-02
Filing date: 2004-03-02
Publication date: 2005-09-15
Anticipated expiration: 2024-03-02
Also published as: JP4386426B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carbonizing oven eliminating drawbacks involved in the established technology, thereby attaining both production cost and utility cost reduction in carbon fiber production, improvement in carbon fiber production process productivity and carbon fiber quality improvement. <P>SOLUTION: The carbonizing oven comprises a heating oven and a seal chamber provided with a flameproofed fiber entrance and a carbon fiber exit for the heating oven, wherein the seal chamber is vertically movable with the transfer plane for flame-proofed fiber as the boundary, and the flame-proofed fiber is continuously carbonized in an inert atmosphere. In this carbonizing oven, it is preferable to have a chamber provided with a feed port via which an inert gas is fed in between the heating oven and the seal chamber. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

本発明は、耐炎化繊維を焼成処理して炭素繊維を製造する炭素化炉に関する。
さらに詳しくは、耐炎化繊維を連続的に導入する入口、炭素繊維を連続的に導出する出口を有しており、加熱炉内で高温の不活性気体により耐炎化繊維を炭素繊維に変換する炉であって、特に、耐炎化繊維・炭素繊維に接触することなく、入口・出口からの不活性気体の漏れを低減することができるシール室を有する炭素化炉に関する。 The present invention relates to a carbonization furnace for producing a carbon fiber by firing a flame-resistant fiber.
More specifically, a furnace that has an inlet for continuously introducing flame-resistant fibers and an outlet for continuously discharging carbon fibers, and converts the flame-resistant fibers into carbon fibers by a high-temperature inert gas in a heating furnace. In particular, the present invention relates to a carbonization furnace having a seal chamber that can reduce leakage of an inert gas from the inlet / outlet without contacting the flameproof fiber / carbon fiber.

炭素繊維は、他の繊維と比較して優れた比強度、比弾性率、金属と比較して優れた比抵抗、高い耐薬品性など多くの優れた特性を有し、その優れた各種特性を利用して樹脂との複合材料用の補強繊維他工業用途に、またスポーツ、航空宇宙分野に幅広く利用されている。 Carbon fiber has many excellent properties, such as superior specific strength and specific modulus compared to other fibers, superior specific resistance compared to metals, and high chemical resistance. It is widely used for reinforcing fibers for composite materials with resins and other industrial applications, and in the sports and aerospace fields.

炭素繊維は、ポリアクリロニトリル、レーヨン等の前駆体糸条を酸化性雰囲気中２００〜３００℃で耐炎化処理した耐炎化繊維を窒素、アルゴン等の不活性雰囲気中８００〜２０００℃以上で炭素化処理することによって得られる。さらに、温度１５００〜３０００℃で黒鉛化を行い、引張弾性率の一段と高い黒鉛繊維を製造することも行われている。本発明では、炭素化と黒鉛化を合わせて単に炭素化と称している。これら炭素化・黒鉛化製造工程では、生産効率を上げるため、炭素化・黒鉛化炉内で耐炎化繊維を多糸条並べて走行させ、所定の処理を施すことが多い。 Carbon fiber is carbonized at 800-2000 ° C or higher in an inert atmosphere such as nitrogen, argon, etc. It is obtained by doing. Furthermore, graphitization is performed at a temperature of 1500 to 3000 ° C. to produce a graphite fiber having a higher tensile modulus. In the present invention, carbonization and graphitization are simply referred to as carbonization. In these carbonization / graphitization production processes, in order to increase production efficiency, a flameproof fiber is often run side by side in a carbonization / graphitization furnace and subjected to a predetermined treatment.

耐炎化繊維の炭素化炉への導入・炭素化炉から導出のために設けられている入口・出口には、抵抗を設けて加熱炉内への空気の流入・加熱炉外への不活性気体の流出を極力抑えるようにシールすることによって、加熱炉内の温度・雰囲気の適正化・均一化を図り、高品質な炭素繊維を得ようとするのが普通ある。
このシールとしては、処理される耐炎化繊維にダメージをあたえないように、ラビリンスシールに代表される非接触型のシールが用いられているが、熱対策、掃除等のメンテナンスの面で不十分であった。 Inlet / outlet provided for introducing flame-resistant fiber into / from the carbonization furnace and providing resistance to inflow / inflow of air into the heating furnace / inert gas to the outside of the heating furnace In order to minimize the outflow of water, the temperature and atmosphere in the heating furnace are usually optimized and uniformed to obtain high-quality carbon fibers.
As this seal, a non-contact type seal typified by a labyrinth seal is used so as not to damage the flame-resistant fiber to be treated. there were.

特許文献１、２には、ハニカム材で構成された多数のセルを多数設けた二次元的なシール室を用いて、幅方向へのラビリンス効果と軽量化とを達成する方法、雰囲気ガス流の乱れによる耐炎化繊維に与えるダメージを極力抑える方法が示されている。 In Patent Documents 1 and 2, a method for achieving a labyrinth effect in the width direction and weight reduction using a two-dimensional seal chamber provided with a large number of cells made of a honeycomb material, an atmospheric gas flow A method of suppressing damage to flame-resistant fibers due to disturbance as much as possible is shown.

この方法では、シール室本体が煩雑な構造となり、シール機構や加熱炉内の掃除を含めたメンテナンスが困難であるといった問題点があった。 In this method, the seal chamber body has a complicated structure, and there is a problem that maintenance including cleaning of the seal mechanism and the heating furnace is difficult.

さらに、特許文献３〜６には液体シールを用いる方法が示されている。これらの方法では、液体の蒸発に細かな配慮が必要であると同時に、蒸発水分の炉内への進入を防止するため、シール装置の構造自体が煩雑なものとなるといった問題があった。 Furthermore, Patent Documents 3 to 6 show a method using a liquid seal. In these methods, there is a problem that fine consideration is required for the evaporation of the liquid, and at the same time, the structure of the sealing device itself becomes complicated in order to prevent the evaporated water from entering the furnace.

特開昭６１−９７４６１号公報JP-A-61-97461 特開昭６２−２４３８３１号公報JP-A-62-243831 特開昭６２−１０５８９号公報Japanese Patent Laid-Open No. 62-10589 特開昭６２−１６２０２１号公報JP-A-62-162021 特開昭５１−１１６２２４号公報JP 51-116224 A 特開昭５１−１１９８３４号公報JP-A-51-119834

本発明では、加熱炉炉内全域にわたり斑のない雰囲気をつくることができ、耐炎化繊維に与えるダメージを極力抑え、シール室・加熱炉内の掃除等のメンテナンス性が良好な、炭素化炉を提供することを目的とする。 In the present invention, a carbonization furnace that can create a spotless atmosphere over the entire area of the heating furnace, suppresses damage to the flame resistant fiber as much as possible, and has good maintainability such as cleaning of the seal chamber and heating furnace. The purpose is to provide.

本発明は、加熱炉とこの加熱炉の耐炎化繊維入口および炭素繊維出口のそれぞれ設置されたシール室からなり、シール室が耐炎化繊維の移送面を境として、独立して上下方向に移動する、耐炎化繊維を不活性雰囲気中で連続的に炭素化する炭素化炉を要旨とする。 The present invention comprises a heating furnace and a seal chamber in which the flameproofing fiber inlet and carbon fiber outlet of the heating furnace are respectively installed, and the sealing chamber moves independently in the vertical direction with the flameproofing fiber transfer surface as a boundary. The gist is a carbonization furnace that continuously carbonizes flame-resistant fibers in an inert atmosphere.

本発明によれば、以下の効果が得られる。
１）加熱炉内全域にわたり斑のない雰囲気をつくることができる。
２）耐炎化繊維に与えるダメージを極力抑えることができ、炭素繊維の品質品位が向上する。
３）シール室、加熱炉ともにメンテナンス性が良好である。
４）炭素繊維の製造に占めるユーティリティー費低減により製造コスト低減が可能である。 According to the present invention, the following effects can be obtained.
1) It is possible to create a spotless atmosphere throughout the heating furnace.
2) The damage given to the flameproof fiber can be suppressed as much as possible, and the quality of the carbon fiber is improved.
3) Good maintainability in both the seal chamber and the heating furnace.
4) Manufacturing costs can be reduced by reducing utility costs in the production of carbon fibers.

以下、本発明の炭素化炉を図面に基づき詳細に説明する。
図１は、本発明の炭素化炉の耐炎化繊維入口と加熱炉の前方部分をのたて断面を示した図である。 Hereinafter, the carbonization furnace of this invention is demonstrated in detail based on drawing.
FIG. 1 is a view showing a vertical cross section of a flameproof fiber inlet of a carbonization furnace and a front part of a heating furnace of the present invention.

図１において、耐炎化繊維１は、シール室上部２Aとシール室下部２Bとの間に形成された間隙を通過して、加熱炉内５に導入される。そして、耐炎化繊維は炭素繊維に転換され、シール室上部とシール室下部（いずれも図示せず）との間に形成された間隙を通過して外部へ導出される。 In FIG. 1, the flameproof fiber 1 is introduced into the heating furnace 5 through a gap formed between the seal chamber upper portion 2A and the seal chamber lower portion 2B. The flameproof fiber is converted into carbon fiber, and is led out through a gap formed between the upper part of the seal chamber and the lower part of the seal chamber (both not shown).

シール室上部２Aとシール室下部２Bは、それぞれ別個に高さ調節機３A、３Bにより上下方向に移動することができ、両者の間に形成された間隙の大きさはこれにより調節することが可能である。シール室内部や加熱炉内部の清掃を行う際には、シール室上部２Aとシール室下部２Bを大きく上下に上げ下げして間隙広くすることができる。 The seal chamber upper part 2A and the seal chamber lower part 2B can be moved vertically by the height adjusters 3A and 3B, respectively, and the size of the gap formed between them can be adjusted accordingly. It is. When cleaning the inside of the seal chamber or the inside of the heating furnace, the upper portion 2A of the seal chamber and the lower portion 2B of the seal chamber can be greatly raised and lowered to widen the gap.

加熱炉内の不活性気体は、たとえば、図１に示したように加熱炉とシール室との間に設けた部屋に不活性気体を供給する供給口４から吐出され、図示していない排気孔から排出される。排気孔は導出側のシール室と加熱炉炉との間に吐出孔と同様に部屋を設け、そこに設けることが好ましい。 The inert gas in the heating furnace is discharged from a supply port 4 for supplying an inert gas to a room provided between the heating furnace and the seal chamber as shown in FIG. Discharged from. The exhaust hole is preferably provided in the same manner as the discharge hole between the outlet-side seal chamber and the furnace and is provided there.

加熱炉内の不活性気体は、大気圧より若干高めに維持することが必要である。 It is necessary to maintain the inert gas in the heating furnace slightly higher than the atmospheric pressure.

シール室上部とシール室下部には、耐炎化繊維（炭素繊維）の進行方向に対して直角方向に隔壁２個以上を設けて形成した膨張室を２段以上有する。膨張室の大きさは、前記間隙とともに、導入する耐炎化繊維（導出する炭素繊維）の厚み、揺れの大きさに応じて調整することが肝要である。 The upper portion of the seal chamber and the lower portion of the seal chamber have two or more expansion chambers formed by providing two or more partition walls in a direction perpendicular to the traveling direction of the flameproof fiber (carbon fiber). It is important to adjust the size of the expansion chamber according to the thickness of the flame-resistant fiber (derived carbon fiber) to be introduced and the magnitude of the shaking, together with the gap.

（実施例）
以下、実施例により本発明を具体的に説明する。
以下の条件は全ての実施例、比較例で同じである。
耐炎化繊維：総繊度１０００テックスの耐炎化繊維
投入繊維数：２００本
加熱炉有効幅：１．３ｍ
処理時間：１．５分
加熱炉内温度：１０００℃
不活性気体供給流量：２００Ｎｍ^３／時間 (Example)
Hereinafter, the present invention will be described specifically by way of examples.
The following conditions are the same in all examples and comparative examples.
Flame-resistant fiber: Number of fibers with flame-resistant fiber with a total fineness of 1000 tex: 200 Heating furnace effective width: 1.3 m
Processing time: 1.5 minutes Heating furnace temperature: 1000 ° C
Inert gas supply flow rate: 200 Nm ³ / hour

シール室上部とシール室下部とに膨張室をそれぞれ２段有する炭素化炉を用い、シール室間隙１０ｍｍとして炭素化を行った。このとき、シール室間隙からの吹出し風量は、５０Nm^３／時間であった。加熱炉内幅方向の風速斑が５％以内と小さく、得られた炭素繊維は強度および品位共に良好なものであった。 Carbonization was performed with a seal chamber gap of 10 mm using a carbonization furnace having two stages of expansion chambers in the upper and lower seal chambers. At this time, the amount of air blown from the gap between the seal chambers was 50 Nm ³ / hour. The wind speed variation in the width direction in the heating furnace was as small as 5% or less, and the obtained carbon fiber was good in both strength and quality.

シール室間隙を１５ｍｍにしたほかは実施例１と同様に炭素化を行った。シール室間隙からの吹出し風量は、６０Nm^３／時間であった。加熱炉内幅方向の風速斑が５％以内と小さく、得られた炭素繊維は強度および品位共に良好なものであった。 Carbonization was performed in the same manner as in Example 1 except that the seal chamber gap was 15 mm. The amount of air blown from the gap between the seal chambers was 60 Nm ³ / hour. The wind speed variation in the width direction in the heating furnace was as small as 5% or less, and the obtained carbon fiber was good in both strength and quality.

シール室上部とシール室下部とに膨張室をそれぞれ４段有する炭素化炉を用い、シール室間隙１０ｍｍとして炭素化を行った。このとき、シール室間隙からの吹出し風量は、３０Nm^３／時間であった。加熱炉内幅方向の風速斑が３％以内と小さく、得られた炭素繊維は強度および品位共に良好なものであった。 Carbonization was performed with a seal chamber gap of 10 mm using a carbonization furnace having four stages of expansion chambers in the upper portion of the seal chamber and the lower portion of the seal chamber. At this time, the amount of air blown from the gap between the seal chambers was 30 Nm ³ / hour. The wind speed variation in the width direction in the heating furnace was as small as 3% or less, and the obtained carbon fiber was good in both strength and quality.

シール室間隙を１５ｍｍにしたほかは実施例３と同様に炭素化を行った。シール室間隙からの吹出し風量は、４０Nm^３／時間であった。加熱炉内幅方向の風速斑が３％以内と小さく、得られた炭素繊維は強度および品位共に良好なものであった。 Carbonization was performed in the same manner as in Example 3 except that the seal chamber gap was 15 mm. The amount of air blown from the seal chamber gap was 40 Nm ³ / hour. The wind speed variation in the width direction in the heating furnace was as small as 3% or less, and the obtained carbon fiber was good in both strength and quality.

本発明の炭素化炉の耐炎化繊維入口と加熱炉の前方部分をのたて断面を示した図The figure which showed the vertical cross section of the flameproof fiber inlet of the carbonization furnace of this invention, and the front part of a heating furnace

Explanation of symbols

１耐炎化繊維
２A シール室上部
２B シール室下部
３A 高さ調節機
３B 高さ調節機
４不活性気体供給口
５加熱炉内
６ヒータ 1 Flame-resistant fiber 2A Upper part of seal chamber 2B Lower part of seal chamber 3A Height adjuster 3B Height adjuster 4 Inert gas supply port 5 Heating furnace 6 Heater

Claims

A flame-resistant fiber consisting of a heating furnace and a seal chamber in which the flame-resistant fiber inlet and carbon fiber outlet of the heating furnace are respectively installed, and the seal chamber moves up and down independently from the flame-resistant fiber transfer surface. A carbonization furnace that continuously carbonizes in an inert atmosphere.

2. The carbonization furnace according to claim 1, further comprising a chamber provided with a supply port for supplying an inert gas between the heating furnace and the seal chamber.