JP2010133059A - Flameproofing furnace, and method for producing carbon fiber using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flameproofing furnace for producing high-quality carbon fibers while improving the operating ratio, and reducing maintenance cost of the flameproofing furnace, and to provide a method for producing the carbon fibers using the flameproofing furnace. <P>SOLUTION: The flameproofing furnace includes: a heat-treating chamber for running a precursor fiber bundle for the carbon fibers a plurality of turns, blowing hot air, and carrying out a flameproofing treatment in the interior thereof; a hot-air circuit for circulating the hot air in the heat-treating chamber; a regulating mechanism for regulating the air velocity of the hot air in the initial running zone to 10-50% of that in the other running zones; and a discharging path for discharging the hot air passing through the initial running zone to the outside of a hot-air circulating system comprising the heat-treating chamber and hot-air circuit. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

本発明は、耐炎化炉及びこれを用いた炭素繊維の製造方法に関する。   The present invention relates to a flameproofing furnace and a method for producing carbon fiber using the same.

炭素繊維は比強度、比弾性率、耐熱性、耐薬品性に優れていることから、各種素材の強化材として有用であり、航空宇宙用途、レジャー用途、一般産業用途等の幅広い分野で使用されている。炭素繊維は、強度を要求される箇所に用いられることが多いため、極めて高い特性の均一性と安定性を備えている必要がある。
一般に、ポリアクリロニトリル系繊維束から炭素繊維束を製造する方法としては、ポリアクリロニトリル系重合体の単繊維を数千から数万本束ねた繊維束（以下、炭素繊維前駆体繊維束と称する。）を、耐炎化炉に送入し、２００〜３００℃に熱せられた空気等の酸化性雰囲気の熱風に晒すことにより耐炎化処理した後、得られた耐炎化繊維束を炭素化炉に送入し、３００〜１０００℃の不活性ガス雰囲気中で加熱処理（前炭素化処理）し、さらに１０００℃以上の不活性ガス雰囲気で満たされた炭素化炉で加熱処理（炭素化処理）する方法が知られている。また、中間材料である耐炎化繊維は、その燃え難い性能を活かして、難燃性織布向けの素材としても広く用いられている。耐炎化処理は炭素繊維前駆体繊維束の発熱を伴う酸化反応であり、耐炎化の途中で単繊維同士が融着しやすい。単繊維が融着した耐炎化繊維束は例えばその後の炭素化処理において、毛羽や糸切れの発生、及び各種特性の低下を引き起こしやすい。 Since carbon fiber is excellent in specific strength, specific elastic modulus, heat resistance, and chemical resistance, it is useful as a reinforcing material for various materials and is used in a wide range of fields such as aerospace applications, leisure applications, and general industrial applications. ing. Since carbon fibers are often used in places where strength is required, it is necessary to have extremely high uniformity of properties and stability.
Generally, as a method for producing a carbon fiber bundle from a polyacrylonitrile fiber bundle, a fiber bundle obtained by bundling thousands to tens of thousands of single fibers of a polyacrylonitrile polymer (hereinafter referred to as a carbon fiber precursor fiber bundle). Was sent to a flameproofing furnace and exposed to hot air in an oxidizing atmosphere such as air heated to 200 to 300 ° C., and then the resulting flameproofed fiber bundle was sent to a carbonization furnace In addition, there is a method of performing heat treatment (pre-carbonization treatment) in an inert gas atmosphere at 300 to 1000 ° C., and further performing heat treatment (carbonization treatment) in a carbonization furnace filled with an inert gas atmosphere at 1000 ° C. or higher. Are known. In addition, the flame-resistant fiber, which is an intermediate material, is widely used as a material for flame-retardant woven fabrics by taking advantage of its incombustible performance. The flameproofing treatment is an oxidation reaction accompanied by heat generation of the carbon fiber precursor fiber bundle, and the single fibers are easily fused together during the flameproofing. The flame-resistant fiber bundle in which the single fibers are fused is liable to cause fluff and yarn breakage and to deteriorate various properties in the subsequent carbonization treatment, for example.

耐炎化繊維の融着を回避するためには、例えば炭素繊維前駆体繊維束に油剤を付与する方法が知られており、それを目的として多くの油剤が検討されている。その中でも、高い耐熱性を有し、かつ融着を効果的に抑えることから、シリコ−ン系油剤がよく用いられている。 工業生産規模の耐炎化処理には、熱風循環方式の耐炎化炉が広く用いられている。熱風循環方式の耐炎化炉は、炭素繊維前駆体繊維束に耐炎化処理を行う熱処理室と、熱風を加熱し循環させるための熱風循環路とによる熱風循環系を有する。熱風循環系によって熱風を何度も繰り返し利用できるため、熱風循環方式の耐炎化炉は、熱エネルギーの損失を少なくできるという利点がある。しかしながら、熱風循環方式の耐炎化炉は、熱風中に滞留する不純物が耐炎化炉内の熱風中に長期にわたり滞留しやすいという欠点がある。特に、炭素繊維前駆体繊維束に付与されたシリコ−ン系油剤は、耐炎化処理の高熱によってその一部が揮発し、熱風中に滞留しやすい。この揮発物は次第に固化して粉塵となり、耐炎化炉内に蓄積したり、耐炎化処理中の炭素繊維前駆体繊維束に付着する。炭素繊維前駆体繊維束に付着した粉塵の付着点は、その後の炭素化処理における毛羽の発生や単糸切れの発生起点となり、得られる炭素繊維束の品質を著しく低下させてしまう。   In order to avoid the fusion of flame resistant fibers, for example, a method of applying an oil agent to a carbon fiber precursor fiber bundle is known, and many oil agents have been studied for that purpose. Among these, silicone oils are often used because they have high heat resistance and effectively suppress fusion. For the industrial production scale flameproofing treatment, a hot air circulation type flameproofing furnace is widely used. The hot air circulation type flameproofing furnace has a hot air circulation system including a heat treatment chamber for performing a flameproofing treatment on the carbon fiber precursor fiber bundle and a hot air circulation path for heating and circulating the hot air. Since the hot air can be repeatedly used by the hot air circulation system, the hot air circulation type flameproof furnace has an advantage that the loss of heat energy can be reduced. However, the hot air circulation type flameproofing furnace has a drawback that impurities staying in the hot air tend to stay in the hot air in the flameproofing furnace for a long time. In particular, a part of the silicone-based oil applied to the carbon fiber precursor fiber bundle volatilizes due to the high heat of the flameproofing treatment, and tends to stay in the hot air. This volatile matter gradually solidifies into dust and accumulates in the flameproofing furnace or adheres to the carbon fiber precursor fiber bundle during the flameproofing treatment. The adhesion point of the dust adhering to the carbon fiber precursor fiber bundle becomes a starting point of fluff generation and single yarn breakage in the subsequent carbonization treatment, and the quality of the obtained carbon fiber bundle is remarkably deteriorated.

耐炎化炉内に滞留する粉塵の大部分は、前記で説明したシリコーン系油剤由来の粉塵であるが、それ以外にも、例えばシリコーン油剤以外の油剤成分の凝集物、炭素繊維前駆体繊維束から発生するタール成分の凝集物、炭素繊維前駆体繊維束に付着した粉塵、耐炎化炉内に流入する外気に含まれる粉塵、及びそれらの複合物からなる粉塵等が挙げられる。これらの粉塵が耐炎化炉内に滞留すると、熱風吹出口の吹出し面に設けられた風速整流用の多孔板が目詰まりを起こして閉塞し、熱風の循環を滞らせてしまう。熱処理室内の熱風の循環が滞ると、炭素繊維前駆体繊維束の除熱が円滑に行われず、炭素繊維前駆体繊維束の糸切れを誘発してしまう。糸切れした炭素繊維前駆体繊維束は、さらに他の炭素繊維前駆体繊維束に絡む等して、他の走行域を走行する炭素繊維先駆体繊維束の糸切れを誘発し、耐炎化炉の安定運転を妨げる原因となる。従って、従来の耐炎化炉では、長期にわたって耐炎化処理工程を稼動させ続けることは困難であり、時に稼動を停止して炉内清掃を行う必要がある。しかし、粒径が数μｍ程度の微粒子を完全に除去することは困難であり、特に大型設備の場合には炉内清掃に要する人員、時間を多大に費やすこととなる。熱風循環方式の耐炎化炉において、炉の稼働率向上、及びメンテナンス費用低減を図るには、耐炎化炉内の粉塵を低減することが有効である。粉塵を低減するには、粉塵の生成要因を取り除く、或いは生成された粉塵を熱風循環系から排出する等が考えられる。 Most of the dust staying in the flameproofing furnace is dust derived from the silicone-based oil described above, but in addition, for example, aggregates of oil agent components other than silicone oil, carbon fiber precursor fiber bundles Examples include agglomerates of generated tar components, dust attached to the carbon fiber precursor fiber bundle, dust contained in the outside air flowing into the flameproofing furnace, and dust composed of a composite thereof. If these dusts stay in the flameproofing furnace, the perforated plate for wind speed rectification provided on the outlet surface of the hot air outlet will be clogged and blocked, and the circulation of hot air will be delayed. If the circulation of hot air in the heat treatment chamber is delayed, the heat removal of the carbon fiber precursor fiber bundle is not performed smoothly, and thread breakage of the carbon fiber precursor fiber bundle is induced. The broken carbon fiber precursor fiber bundles are further entangled with other carbon fiber precursor fiber bundles to induce thread breakage of the carbon fiber precursor fiber bundles traveling in other traveling areas, and It may cause a hindrance to stable operation. Therefore, in the conventional flameproofing furnace, it is difficult to keep the flameproofing process operating for a long time, and it is sometimes necessary to stop the operation and clean the furnace. However, it is difficult to completely remove fine particles having a particle size of about several μm, and particularly in the case of a large facility, a great amount of personnel and time are required for cleaning the inside of the furnace. In a hot air circulation type flameproofing furnace, it is effective to reduce dust in the flameproofing furnace in order to improve the operating rate of the furnace and reduce maintenance costs. In order to reduce the dust, it is conceivable to remove the generation factor of the dust or to discharge the generated dust from the hot air circulation system.

この課題に対し、例えば特許文献１では、熱風循環路に排気口を設けた耐炎化炉が提案されている。この耐炎化炉によれば、炉内清掃後の再稼動前に、熱風循環系の熱風を排気口から熱風循環系の外に排気するので、耐炎化炉内に残留する粉塵を低減でき、以って再稼動後の初期に生じる耐炎化繊維束の品質低下を防ぐことができるとしている。しかしながら、特許文献１では、耐炎化炉の再稼動後の初期に生じる耐炎化繊維束の品質低下を防ぐことはできるものの、粉塵の発生を抑制できるわけではないため、耐炎化炉の清掃の頻度を低減することはできない。
特開平８−３１１７２３号公報 In response to this problem, for example, Patent Document 1 proposes a flameproof furnace in which an exhaust port is provided in a hot air circulation path. According to this flameproofing furnace, the hot air in the hot air circulation system is exhausted from the exhaust port to the outside of the hot air circulation system before restarting after cleaning the inside of the furnace, so that dust remaining in the flameproofing furnace can be reduced. Thus, it is possible to prevent deterioration in the quality of the flame-resistant fiber bundle that occurs in the initial stage after re-operation. However, in Patent Document 1, although it is possible to prevent deterioration in the quality of the flame-resistant fiber bundle that occurs in the initial stage after the reactivation of the flame-resistant furnace, it is not possible to suppress the generation of dust, so the frequency of cleaning the flame-resistant furnace is low. Can not be reduced.
JP-A-8-31723

本発明は、耐炎化炉の稼働率向上、及びメンテナンス費用低減を図りつつ、高品質の炭素繊維を生産するための耐炎化炉と、これを用いた炭素繊維の製造方法を提供することを目的とする。 An object of the present invention is to provide a flameproofing furnace for producing high-quality carbon fiber while improving the operating rate of the flameproofing furnace and reducing maintenance costs, and a method for producing carbon fiber using the same. And

前記の課題を達成するために、本発明は以下の構成を採用した。
[１] その内部で、炭素繊維前駆体繊維束を複数回走行させ、かつ熱風を吹き付けて耐炎化処理する熱処理室と、
前記熱処理室内の熱風を循環させる熱風循環路と、
初期走行域の熱風の風速を、その他走行域の風速の１０〜５０％に調整する調整機構と、
前記初期走行域を通過した熱風を、前記熱処理室と前記熱風循環路からなる熱風循環系の外に排出する排出路と、
を備えた耐炎化炉。 In order to achieve the above object, the present invention adopts the following configuration.
[1] Inside thereof, a heat treatment chamber for running the carbon fiber precursor fiber bundle a plurality of times and spraying hot air to make it flameproof,
A hot air circulation path for circulating hot air in the heat treatment chamber;
An adjustment mechanism for adjusting the wind speed of the hot air in the initial travel area to 10 to 50% of the wind speed in the other travel areas;
A discharge path for discharging the hot air that has passed through the initial traveling area out of the hot air circulation system including the heat treatment chamber and the hot air circulation path;
A flameproof furnace equipped with

[２] 熱処理室の内部で炭素繊維前駆体繊維束を複数回走行させ、かつ熱風を吹き付けて耐炎化処理を行う炭素繊維の製造方法であって、
初期走行域の熱風の風速を、その他走行域の風速の１０〜５０％とし、
前記その他走行域を通過した熱風を、熱風循環路を介して前記熱処理室の内部で循環させ、
前記初期走行域を通過した熱風を、前記熱処理室と前記熱風循環路からなる熱風循環系の外に排出する、
炭素繊維の製造方法。 [2] A carbon fiber manufacturing method in which a carbon fiber precursor fiber bundle is run a plurality of times inside a heat treatment chamber and a flameproofing treatment is performed by blowing hot air.
The wind speed of the hot air in the initial travel area is 10-50% of the wind speed in the other travel areas,
The hot air that has passed through the other traveling area is circulated inside the heat treatment chamber via a hot air circulation path,
The hot air that has passed through the initial traveling area is discharged out of the hot air circulation system that includes the heat treatment chamber and the hot air circulation path.
A method for producing carbon fiber.

本発明の耐炎化炉及び炭素繊維の製造方法によれば、高品質な炭素繊維を得ることができ、かつ耐炎化炉の長期的な連続稼動が可能となる。   According to the flameproofing furnace and carbon fiber manufacturing method of the present invention, high-quality carbon fiber can be obtained, and long-term continuous operation of the flameproofing furnace becomes possible.

図１に示すように、本発明の耐炎化炉１０は、熱処理室２と、前記熱処理室２内の熱風を循環させるための熱風循環路８とを備えた熱風循環方式の耐炎化炉である。この耐炎化炉は、熱処理室２外の側壁に設けられたガイドロール３を用いて、炭素繊維前駆体繊維束１を折り返しながら熱処理室２の内部を複数回走行させ、かつ炭素繊維前駆体繊維束１に熱風を吹き付けて耐炎化処理する。
前記熱処理室２は、炭素繊維前駆体繊維束１の初期走行域に配された熱風吹出口４ａ及び熱風排出口５ａと、その他走行域に配された熱風吹出口４及び熱風排出口５とを備える。また、熱風循環路８の経路途中には、熱風を加熱する加熱器６と、熱風の送風器７と、初期走行域を通過する熱風量を調整する調整機構１８とが配されている。
ここで初期走行域とは、炭素繊維前駆体繊維束１の密度ρ₀、耐炎化の反応停止時の密度ρ_∞、初期走行域通過後の密度ρとしたとき、下式（１）から求める耐炎化進行度が５以下である範囲をいう。
耐炎化進行度 ＝（ρ−ρ₀）／（ρ_∞−ρ₀）×１００ ・・・・式（１） As shown in FIG. 1, the flameproofing furnace 10 of the present invention is a hot air circulation type flameproofing furnace having a heat treatment chamber 2 and a hot air circulation path 8 for circulating hot air in the heat treatment chamber 2. . This flameproofing furnace uses the guide roll 3 provided on the side wall outside the heat treatment chamber 2 to run the inside of the heat treatment chamber 2 a plurality of times while turning the carbon fiber precursor fiber bundle 1 back, and the carbon fiber precursor fibers. The bundle 1 is subjected to flameproofing treatment by blowing hot air.
The heat treatment chamber 2 includes a hot air outlet 4a and a hot air outlet 5a disposed in the initial traveling area of the carbon fiber precursor fiber bundle 1, and a hot air outlet 4 and a hot air outlet 5 disposed in the other traveling area. Prepare. In the middle of the hot air circulation path 8, a heater 6 that heats the hot air, a blower 7 for the hot air, and an adjustment mechanism 18 that adjusts the amount of the hot air passing through the initial travel area are arranged.
Here, the initial running area is obtained from the following equation (1) when the density ρ ₀ of the carbon fiber precursor fiber bundle 1, the density ρ _∞ at the time of stopping the flame resistance reaction, and the density ρ after passing through the initial running area. It refers to a range in which the progress of flame resistance is 5 or less.
Flameproofing progression = (ρ−ρ ₀ ) / (ρ _∞ −ρ ₀ ) × 100 (1)

炭素繊維前駆体繊維束１は、熱処理室２の側壁に設けたスリットから熱処理室２内に送入され、熱処理室２内を直線的に走行した後、対面の側壁のスリットから熱処理室２外に一旦送出され、熱処理室２外の側壁に設けられたガイドロール３によって折り返され、再び熱処理室２内に送入される。このように、炭素繊維前駆体繊維束１は複数のガイドロール３によって複数回折り返すことで、熱処理室２の内部を複数回走行し、熱処理室２内を全体として図１の下から上に向けて移動する。なお、炭素繊維前駆体繊維１の折り返し回数は特に限定されず、耐炎化炉の規模等によって適宜設計される。
炭素繊維前駆体繊維束１は、このように熱処理室２の内部を走行している間に、熱風吹出口４a及び４から吹き付けられる熱風によって耐炎化処理される。なお、図示しないが、炭素繊維前駆体繊維束１は、紙面に対して垂直な方向即ち水平方向に複数本並行させてシート状に引き揃えられた形態を有している。 The carbon fiber precursor fiber bundle 1 is fed into the heat treatment chamber 2 from a slit provided on the side wall of the heat treatment chamber 2 and travels linearly in the heat treatment chamber 2, and then passes through the slit on the opposite side wall from the heat treatment chamber 2. And is then turned back by the guide roll 3 provided on the side wall outside the heat treatment chamber 2 and again fed into the heat treatment chamber 2. As described above, the carbon fiber precursor fiber bundle 1 is diffracted multiple times by the plurality of guide rolls 3 so that the carbon fiber precursor fiber bundle 1 travels inside the heat treatment chamber 2 a plurality of times, and the inside of the heat treatment chamber 2 as a whole is directed from bottom to top in FIG. Move. In addition, the frequency | count of folding of the carbon fiber precursor fiber 1 is not specifically limited, It designs suitably by the scale etc. of a flame-proofing furnace.
The carbon fiber precursor fiber bundle 1 is flameproofed by hot air blown from the hot air outlets 4a and 4 while traveling inside the heat treatment chamber 2 in this manner. Although not shown, the carbon fiber precursor fiber bundle 1 has a form in which a plurality of carbon fiber precursor fiber bundles 1 are arranged in parallel in a direction perpendicular to the paper surface, that is, in the horizontal direction.

本発明の耐炎化炉１０は、初期走行域を通過した熱風を、熱処理室２と熱風循環路８からなる熱風循環系の外に排出する排出路１１を備える。初期走行域において、熱風は、熱風吹出口４aから吹き込まれ、熱処理室２の初期走行域を流れ、熱風排出口５ａから排出路１１に導かれて、熱風循環系の外に排出される。排出路１１には、排気ファン１２を設けて、熱風排出口５ａからの熱風の排出を補助するのが好ましい。
熱風吹出口４及び４ａは、その吹き出し面に多孔板等の抵抗体及びハニカム等の整流部材（ともに不図示）を配して圧力損失を持たせるのが好ましい。これにより、熱処理室２内に吹き込む熱風は整流され、熱風がより均一な風速で熱処理室２の内部に吹き込まれる。熱風排出口５及び５ａは、熱風吹出口４と同様に、その吸い込み面に多孔板等の抵抗体を配して圧力損失を持たせてもよい。 The flameproofing furnace 10 of the present invention includes a discharge path 11 that discharges hot air that has passed through the initial traveling area to the outside of the hot air circulation system including the heat treatment chamber 2 and the hot air circulation path 8. In the initial travel region, hot air is blown from the hot air outlet 4a, flows through the initial travel region of the heat treatment chamber 2, is guided to the discharge path 11 from the hot air discharge port 5a, and is discharged out of the hot air circulation system. It is preferable to provide an exhaust fan 12 in the discharge path 11 to assist the discharge of hot air from the hot air discharge port 5a.
The hot air outlets 4 and 4a are preferably provided with pressure loss by arranging a resistor such as a perforated plate and a rectifying member such as a honeycomb (both not shown) on the blowing surface. Thereby, the hot air blown into the heat treatment chamber 2 is rectified, and the hot air is blown into the heat treatment chamber 2 at a more uniform wind speed. Similarly to the hot air outlet 4, the hot air outlets 5 and 5 a may be provided with a pressure loss by arranging a resistor such as a perforated plate on the suction surface.

熱処理室２は、初期走行域以外のその他走行域において熱処理室２と熱風循環路８からなる熱風循環系を有している。その他走行域では、熱風は熱風吹出口４から熱処理室２内に吹き込まれ、熱処理室２内部を矢印の方向すなわち排出口５側に向かって、炭素繊維前駆体繊維束１の走行方向と平行に流れる。熱風は、熱風排出口５から熱風循環路８に導かれる。そして、熱風循環路８の途中に設けられた加熱器６によって所望の温度に制御され、送風器７によって風速が制御される。そして再び熱風吹出口４から熱処理室２の内部に吹き込まれる。こうして、熱処理室２内には、常に所定の温度と風速の熱風が流れるようになっている。   The heat treatment chamber 2 has a hot air circulation system including the heat treatment chamber 2 and the hot air circulation path 8 in other travel regions other than the initial travel region. In the other traveling area, the hot air is blown into the heat treatment chamber 2 from the hot air outlet 4, and the inside of the heat treatment chamber 2 is directed in the direction of the arrow, that is, toward the discharge port 5, in parallel with the traveling direction of the carbon fiber precursor fiber bundle 1. Flowing. Hot air is guided from the hot air outlet 5 to the hot air circulation path 8. Then, a desired temperature is controlled by a heater 6 provided in the hot air circulation path 8, and the wind speed is controlled by a blower 7. Then, it is blown again into the heat treatment chamber 2 from the hot air outlet 4. Thus, hot air having a predetermined temperature and wind speed always flows in the heat treatment chamber 2.

なお、本発明の耐炎化炉１０に用いられる加熱器６としては、所望の機能を有していれば特に限定されず、例えば電気ヒーター等の公知の加熱器を用いればよい。送風器７に関しても、所望の機能を有していれば特に限定されず、例えば軸流ファン等の公知の送風器を用いればよい。
また熱処理室２は、その他走行域において炭素繊維前駆体繊維束１から発生するＨＣＮ等のガスの濃度を一定値以下に抑えるため、これらのガスを含んだ熱風を、熱風循環系の外に排出するための排気ファン１６、及びガスを処理するための排ガス燃焼装置１７を備えることが好ましい。 The heater 6 used in the flameproofing furnace 10 of the present invention is not particularly limited as long as it has a desired function. For example, a known heater such as an electric heater may be used. The blower 7 is not particularly limited as long as it has a desired function. For example, a known blower such as an axial fan may be used.
Further, the heat treatment chamber 2 discharges hot air containing these gases out of the hot air circulation system in order to keep the concentration of gas such as HCN generated from the carbon fiber precursor fiber bundle 1 below a certain value in other traveling regions. It is preferable to include an exhaust fan 16 for exhaust gas and an exhaust gas combustion device 17 for processing gas.

初期走行域の風速は、その他走行域の風速の１０％〜５０％とする。１０％以上あれば、炭素繊維前駆体繊維束を加熱、昇温する効果が十分得られる。また、５０％以下であれば熱風を系外に排出することによる熱ロスと排出したガスを処理するために必要なエネルギーロスを低く抑えることができる。
初期走行域の風速をその他走行域の風速の１０％〜５０％とするには、例えば熱風循環路８から初期走行域の熱風吹出口４ａまでの間にダンパー１８を設け、風量を調節すればよい。この際、その他走行域の熱風吹出口４までの間にダンパー１９を設けると、より風量の制御が容易となる。また、熱風吹出し口４，４ａに設置する整流部材の開口率を変えたり、流路の圧力損失を変えたりすることで同様の効果を得ることも可能である。
また例えば図２に示す耐炎化炉２０のように、初期走行域とその他走行域との間に仕切り板９を設けることも可能である。仕切り板９を設けることで、熱処理室２内を初期走行域に該当する熱処理区画２ａとその他走行域に該当する熱処理区画２ｂとに区分けでき、初期走行域を流れる熱風を効率的に熱風排出口５ａに導くことができる。なお、仕切り板９は、熱処理区画２ａと熱処理区画２ｂとの間を完全に仕切っていてもよいが、部分的に仕切っているだけでもよい。なお、図２の耐炎化炉２０の符号について、図１の耐炎化炉１０の各構成と同様の構成物に関しては、便宜上、図１と同じ符号を付して、説明を省略する。 The wind speed in the initial travel area is 10% to 50% of the wind speed in the other travel areas. If it is 10% or more, the effect of heating and raising the temperature of the carbon fiber precursor fiber bundle is sufficiently obtained. Moreover, if it is 50% or less, the heat loss by discharging | emitting hot air out of a system and the energy loss required in order to process the discharged | emitted gas can be suppressed low.
In order to set the wind speed in the initial travel area to 10% to 50% of the wind speed in the other travel areas, for example, a damper 18 is provided between the hot air circulation path 8 and the hot air outlet 4a in the initial travel area, and the air volume is adjusted. Good. At this time, if the damper 19 is provided between the hot air outlet 4 in the other traveling area, the air volume can be controlled more easily. It is also possible to obtain the same effect by changing the opening ratio of the rectifying member installed in the hot air outlets 4 and 4a or changing the pressure loss of the flow path.
For example, like the flameproof furnace 20 shown in FIG. 2, it is also possible to provide the partition plate 9 between the initial travel area and the other travel areas. By providing the partition plate 9, the inside of the heat treatment chamber 2 can be divided into a heat treatment section 2a corresponding to the initial travel area and a heat treatment section 2b corresponding to the other travel area, and hot air flowing through the initial travel area can be efficiently discharged into the hot air outlet. 5a. The partition plate 9 may completely partition between the heat treatment compartment 2a and the heat treatment compartment 2b, or may only partly partition. For the reference numerals of the flameproofing furnace 20 in FIG. 2, the same reference numerals as those in FIG.

炭素繊維前駆体繊維束１からのシリコーン系油剤の揮発物は、初期走行域にて大量に発生する。初期走行域は通常熱処理室２内へ最初に送入された直後から数分の間に相当する。そのため、初期走行域を流れた熱風中には、シリコーン系油剤の揮発物が多く含まれている。ゆえに、初期走行域を通過した熱風を、熱風循環系の外へ排出してやれば、熱風循環系に滞留するシリコーン系油剤の揮発物を大幅に低減させることができる。該揮発物の滞留を低減できれば、該揮発物から生じる粉塵の発生も減少する。
このように、本発明の耐炎化炉１０は、熱エネルギーの損失が少ないという熱風循環方式の利点を有しながら、熱風循環方式の欠点である粉塵の滞留を低減できる。ゆえに、耐炎化炉内の清掃の頻度を低減できるため、従来の耐炎化炉に比べてメンテナンス費用を大幅に軽減できる。また、耐炎化炉の長期的な連続稼動が可能となることで、耐炎化繊維の生産性が向上できる。さらには、粉塵による耐炎化繊維の品質低下を抑えることができるので、高品質な耐炎化繊維束を均一かつ安定して製造できる。 A large amount of the volatile matter of the silicone-based oil agent from the carbon fiber precursor fiber bundle 1 is generated in the initial traveling region. The initial running area usually corresponds to a few minutes immediately after being first fed into the heat treatment chamber 2. For this reason, the hot air flowing through the initial travel region contains a large amount of volatile substances of silicone oil. Therefore, if the hot air that has passed through the initial travel region is discharged out of the hot air circulation system, the volatiles of the silicone-based oil that stays in the hot air circulation system can be greatly reduced. If the retention of the volatile matter can be reduced, the generation of dust generated from the volatile matter is also reduced.
Thus, the flameproofing furnace 10 of the present invention can reduce the retention of dust, which is a drawback of the hot air circulation system, while having the advantage of the hot air circulation system that there is little loss of thermal energy. Therefore, since the frequency of cleaning in the flameproofing furnace can be reduced, the maintenance cost can be greatly reduced as compared with the conventional flameproofing furnace. In addition, the long-term continuous operation of the flameproofing furnace becomes possible, so that the productivity of the flameproofing fiber can be improved. Furthermore, since the quality deterioration of the flame-resistant fiber due to dust can be suppressed, a high-quality flame-resistant fiber bundle can be produced uniformly and stably.

初期走行域から循環系の外に排出される熱風中には、シリコーン系油剤の揮発物の他に、炭素繊維前駆体繊維束１が耐炎化する際に発生するＨＣＮ等のガス等も含まれている。従って、排出経路に排ガス燃焼装置１３を設けて、初期走行域から循環系の外に排出される熱風に含まれるシリコーン系油剤の揮発物を固体の酸化珪素粒子に酸化し、かつＨＣＮ等のガスも酸化処理することが好ましい。
また、熱風排出口５ａからの熱風中には、粉塵が多く含まれるため、粉塵を集塵するための集塵装置１４を排出経路に設けることが好ましい。
なお、排ガス燃焼装置１３としては、所望の機能を有していれば特に限定されず、公知の排ガス燃焼装置を用いればよい。また、集塵装置１４に関しても、所望の機能を有していれば特に限定されず、例えばバグフィルター等の公知の集塵装置を用いればよい。また、排ガス燃焼装置１３及び集塵装置１４は単数に限定されず、機能分担や性能強化等を目的として複数設けてもよい。 The hot air discharged from the initial running area to the outside of the circulation system includes gas such as HCN generated when the carbon fiber precursor fiber bundle 1 becomes flame resistant in addition to the volatiles of the silicone-based oil agent. ing. Therefore, the exhaust gas combustion device 13 is provided in the discharge path to oxidize the volatiles of the silicone-based oil contained in the hot air discharged out of the circulation system from the initial traveling region into solid silicon oxide particles, and to gas such as HCN Is preferably oxidized.
Moreover, since a lot of dust is contained in the hot air from the hot air discharge port 5a, it is preferable to provide a dust collecting device 14 for collecting the dust in the discharge path.
The exhaust gas combustion device 13 is not particularly limited as long as it has a desired function, and a known exhaust gas combustion device may be used. The dust collector 14 is not particularly limited as long as it has a desired function. For example, a known dust collector such as a bag filter may be used. Further, the exhaust gas combustion device 13 and the dust collection device 14 are not limited to a single number, and a plurality may be provided for the purpose of sharing functions or enhancing performance.

また、熱処理室２から熱風が排出されることにより失われる空気を補うために、外気取入口１５を設けて、そこから外気（酸化性気体）を補充してもよい。外気取入口１５の設置場所は、所望の機能を果せれば特に限定されないが、好ましくは循環路８の加熱器６上流に配置される。これにより、取り込んだ外気を加熱器６で加熱してから熱処理室２内に送り込むことができる。なお、外気取入口１５には、外気に混入する粉塵等を除去するためにフィルタ（不図示）を備えていることが好ましい。外気取入口１５からの外気の取り込みには、送風ファンや調整弁（ともに不図示）等を用いて、その取り込み量を制御してもよいし、排出手段からの熱風の排出に応じて受動的に取り込まれてもよい。   Moreover, in order to supplement the air lost when hot air is discharged from the heat treatment chamber 2, an outside air intake 15 may be provided to replenish outside air (oxidizing gas) therefrom. The installation location of the outside air inlet 15 is not particularly limited as long as it can perform a desired function, but is preferably disposed upstream of the heater 6 in the circulation path 8. Thereby, the taken-out outside air can be sent into the heat treatment chamber 2 after being heated by the heater 6. The outside air inlet 15 is preferably provided with a filter (not shown) in order to remove dust and the like mixed in the outside air. The intake of outside air from the outside air intake 15 may be controlled by using a blower fan, a regulating valve (both not shown) or the like, or passively according to the discharge of hot air from the discharge means. May be included.

さらには、排出手段に設けた廃熱回収装置（不図示）によって、排出路１１を通過する熱風から廃熱回収を行い、回収された廃熱を外気取入口１５から取り込まれる外気の加熱に用いることもできる。これにより、あらかじめ加熱した外気を耐炎化炉１０内に送り込むことができ、加熱器６の負担を低減できる。なお、排ガス燃焼装置に廃熱回収装置を組み込むこともできる。   Further, the waste heat recovery device (not shown) provided in the discharge means recovers waste heat from the hot air passing through the discharge path 11 and uses the recovered waste heat for heating the outside air taken in from the outside air inlet 15. You can also. Thereby, the external air heated previously can be sent in into the flame-proofing furnace 10, and the burden of the heater 6 can be reduced. Note that a waste heat recovery device can be incorporated into the exhaust gas combustion device.

なお、本発明の耐炎化炉は前駆体繊維束１が上から下に移動する場合にも同様に構成することができる。また前記においては、いわゆる横型耐炎化炉について説明したが、熱処理室２が上下方向に延びる縦型耐炎化炉も全く同様に構成することができる。   Note that the flameproofing furnace of the present invention can be similarly configured when the precursor fiber bundle 1 moves from top to bottom. In the above description, a so-called horizontal flameproofing furnace has been described. However, a vertical flameproofing furnace in which the heat treatment chamber 2 extends in the vertical direction can be configured in exactly the same manner.

また、本発明の耐炎化炉１０、２０は炭素繊維の製造工程で複数使用してもよい。なお、シリコーン油剤由来の揮発物は、その大部分が耐炎化処理の初期において発生するため、複数の耐炎化炉を用いた炭素繊維の製造においては、少なくとも最初の耐炎化処理を行う耐炎化炉に、本発明の耐炎化炉１０、２０を用いることが好ましい。これにより、前駆体繊維束１からの揮発物を熱処理室２内から効率よく取り除くことができ、揮発物が凝集して発生する粉塵の量を抑制できる。よって、本発明の耐炎化炉１０、２０を用いれば、複数の耐炎化炉を使用した場合においても、複数の耐炎化炉の長期的な連続運転が可能となる。
また、本発明の耐炎化炉１０、２０は、主に炭素繊維を得るための前駆体繊維束１の耐炎化処理に好ましく用いられるが、他にも、例えば糸やフィルム、シート等といった各種の熱処理にも使用できる。 Moreover, you may use multiple flameproofing furnaces 10 and 20 of this invention in the manufacturing process of carbon fiber. In addition, since most of the volatiles derived from the silicone oil are generated at the initial stage of the flameproofing treatment, in the production of carbon fiber using a plurality of flameproofing furnaces, a flameproofing furnace that performs at least the first flameproofing treatment. In addition, it is preferable to use the flameproofing furnaces 10 and 20 of the present invention. Thereby, the volatile matter from the precursor fiber bundle 1 can be efficiently removed from the heat treatment chamber 2, and the amount of dust generated by aggregation of the volatile matter can be suppressed. Therefore, if the flameproofing furnaces 10 and 20 of the present invention are used, a plurality of flameproofing furnaces can be operated continuously for a long time even when a plurality of flameproofing furnaces are used.
The flameproofing furnaces 10 and 20 of the present invention are preferably used mainly for the flameproofing treatment of the precursor fiber bundle 1 for obtaining carbon fibers, but various other types such as yarns, films, sheets, etc. Can also be used for heat treatment.

次に、本発明の耐炎化炉１０、２０を用いた炭素繊維の製造方法について説明する。本発明の炭素繊維の製造方法に用いられる炭素繊維前駆体繊維としては、ポリアクリロニトリル系繊維、ピッチ系繊維、フェノール系繊維等の公知の炭素繊維前駆体繊維を挙げることができるが、コストと性能のバランスから、好ましくはポリアクリロニトリル系繊維が用いられる。
ポリアクリロニトリル系繊維は、アクリルニトリル系重合体を有機溶剤あるいは無機溶剤に溶解し、通常用いられる方法にて紡糸されるが、特にその紡糸方法、及び紡糸条件に制限はない。 Next, the manufacturing method of the carbon fiber using the flameproofing furnaces 10 and 20 of this invention is demonstrated. Examples of the carbon fiber precursor fiber used in the carbon fiber production method of the present invention include known carbon fiber precursor fibers such as polyacrylonitrile fiber, pitch fiber, phenol fiber, etc., but cost and performance From the above balance, polyacrylonitrile fibers are preferably used.
Polyacrylonitrile fibers are prepared by dissolving an acrylonitrile polymer in an organic solvent or an inorganic solvent and spinning by a commonly used method, but the spinning method and spinning conditions are not particularly limited.

アクリロニトリル系重合体の成分の割合としては特に制限はないが、アクリロニトリル単位を８５重量％以上、より好ましくは９０重量％以上を含有する重合体を使用する。アクリロニトリル系重合体としては、アクリロニトリル単独重合体またはアクリロニトリル共重合体を用いることができる。
アクリロニトリル共重合体は、アクリロニトリルと共重合しうる単量体と、アクリロニトリル単量体との共重合生成物である。アクリロニトリルと共重合しうる単量体としては、メチル（メタ）アクリレ−ト、エチル（メタ）アクリレ−ト、プロピル（メタ）アクリレ−ト、ブチル（メタ）アクリレ−ト、ヘキシル（メタ）アクリレ−ト等の（メタ）アクリル酸エステル類、塩化ビニル、臭化ビニル、塩化ビニリデン等のハロゲン化ビニル類、（メタ）アクリル酸、イタコン酸、クロトン酸等の酸類及びそれらの塩類や、マレイン酸イミド、フェニルマレイミド、（メタ）アクリルアミド、スチレン、α−メチルスチレン、酢酸ビニル、更にはスチレンスルホン酸ソ−ダ、アリルスルホン酸ソ−ダ、β−スチレンスルホン酸ソ−ダ、メタアリルスルホン酸ソ−ダ等のスルホン基を含む重合性不飽和単量体、２−ビニルピリジン、２−メチル−５−ビニルピリジン等のピリジン基を含む重合性不飽和単量体、等が挙げられる。 Although there is no restriction | limiting in particular as a ratio of the component of an acrylonitrile type | system | group polymer, The polymer containing 85 weight% or more of acrylonitrile units, More preferably, 90 weight% or more is used. As the acrylonitrile-based polymer, an acrylonitrile homopolymer or an acrylonitrile copolymer can be used.
The acrylonitrile copolymer is a copolymerized product of a monomer copolymerizable with acrylonitrile and an acrylonitrile monomer. Monomers that can be copolymerized with acrylonitrile include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and hexyl (meth) acrylate. (Meth) acrylic acid esters such as vinyl chloride, vinyl halides such as vinyl chloride, vinyl bromide and vinylidene chloride, acids such as (meth) acrylic acid, itaconic acid and crotonic acid and their salts, and maleic acid imide , Phenylmaleimide, (meth) acrylamide, styrene, α-methylstyrene, vinyl acetate, styrene sulfonate, allyl sulfonate, β-styrene sulfonate, methallyl sulfonate Polymerizable unsaturated monomers containing a sulfone group such as 2-vinylpyridine, 2-methyl-5-vinylpyridine and the like Examples thereof include polymerizable unsaturated monomers containing a gin group.

アクリロニトリル系重合体の重合法については、従来公知の溶液重合、懸濁重合、乳化重合等を適用できる。アクリロニトリル系重合体の溶液作製に使用される溶媒としては、ジメチルスルホキシド、ジメチルアセトアミド、ジメチルホルムアミド、塩化亜鉛水溶液、硝酸等の公知の溶媒を使用できる。なお、アクリロニトリル系重合体の紡糸方法には、湿式紡糸法、乾湿式紡糸法、乾式紡糸法等の公知の紡糸方法を適用できる。
このようにして得られた凝固糸は、次いで一次延伸される。一次延伸の方法としては、公知の方法を用いることができるが、好ましくは浴中延伸が用いられる。浴中延伸は、５０〜９８℃程度の凝固糸を凝固浴中または延伸浴中で延伸する延伸方法である。浴中延伸は、凝固糸に対して１回または２回以上行われる。この他にも、一部空中延伸した後に浴中延伸する等、複数の延伸方法を組み合わせてもよい。また、一次延伸の前後、あるいは一次延伸と同時に、公知の方法による洗浄処理を行ってもよい。 As the polymerization method for the acrylonitrile-based polymer, conventionally known solution polymerization, suspension polymerization, emulsion polymerization and the like can be applied. As the solvent used for preparing the acrylonitrile polymer solution, known solvents such as dimethyl sulfoxide, dimethylacetamide, dimethylformamide, zinc chloride aqueous solution, nitric acid and the like can be used. In addition, known spinning methods such as a wet spinning method, a dry and wet spinning method, and a dry spinning method can be applied to the spinning method of the acrylonitrile-based polymer.
The coagulated yarn thus obtained is then primarily drawn. As a method for primary stretching, a known method can be used, but stretching in a bath is preferably used. Stretching in a bath is a stretching method in which a coagulated yarn of about 50 to 98 ° C. is stretched in a coagulation bath or in a stretching bath. The drawing in the bath is performed once or twice or more on the coagulated yarn. In addition to this, a plurality of stretching methods such as partially stretching in the air and then stretching in the bath may be combined. Moreover, you may perform the washing process by a well-known method before and after primary extending | stretching, or simultaneously with primary extending | stretching.

このようにして得られたポリアクリロニトリル系繊維からなる炭素繊維前駆体繊維束１には、次いで油剤処理が行われ、さらに二次延伸処理が行われる。油剤処理において、シリコーン系化合物を含む油剤（シリコーン系油剤）を用いることが好ましい。   The carbon fiber precursor fiber bundle 1 made of the polyacrylonitrile fiber thus obtained is then subjected to an oil agent treatment and further subjected to a secondary stretching treatment. In the oil treatment, it is preferable to use an oil containing a silicone compound (silicone oil).

油剤処理によって、紡糸工程における前駆体繊維束１の収束性、柔軟性、平滑性、工程安定性、及び帯電防止性が向上する。さらに耐炎化処理及び炭素化処理における、通過性、収束性、及び融着防止性が向上する。
特に、シリコーン系油剤は、炭素繊維前駆体繊維束１に対して優れた収束性と工程安定性を与えることができ、さらに耐炎化処理及び炭素化処理における優れた通過性を得ることができ、特に炭素化処理での融着防止に顕著な効果を発揮する。
なお、シリコーン系油剤に含まれるシリコーン系化合物としては、アミノ変性シリコーンが好ましく用いられる。アミノ変性シリコーンの中でも、特に側鎖1級アミノ変性シリコーン、側鎖１,２級アミノ変性シリコーン、あるいは両末端アミノ変性シリコーンが好ましく用いられる。 The oil agent treatment improves the convergence, flexibility, smoothness, process stability, and antistatic properties of the precursor fiber bundle 1 in the spinning process. Furthermore, in the flame resistance treatment and the carbonization treatment, passability, convergence, and anti-fusing properties are improved.
In particular, the silicone-based oil agent can give excellent convergence and process stability to the carbon fiber precursor fiber bundle 1, and can further obtain excellent permeability in flameproofing treatment and carbonization treatment, In particular, it has a remarkable effect in preventing fusion in the carbonization treatment.
An amino-modified silicone is preferably used as the silicone compound contained in the silicone oil. Among amino-modified silicones, side-chain primary amino-modified silicone, side-chain 1, secondary amino-modified silicone, or both-end amino-modified silicone is particularly preferably used.

炭素繊維前駆体繊維束１に油剤を付与する方法については特に制限はないが、一般に、油剤と水を含む処理液が入った油剤処理槽に、炭素繊維前駆体繊維束１を浸漬させて油剤を付着させるのが、工業的な面から好ましい。
油剤処理による炭素繊維前駆体繊維束１の油剤の付着量は、乾燥した炭素繊維前駆体繊維束１に対して０．１〜３．０質量％が好ましい。油剤の付着量を調整する方法としては、例えば処理液中の油剤濃度の調整、または炭素繊維前駆体繊維束１に浸漬させた処理液をニップロール等によって絞ることで調整できる。 Although there is no restriction | limiting in particular about the method of providing an oil agent to the carbon fiber precursor fiber bundle 1, Generally, the carbon fiber precursor fiber bundle 1 is immersed in the oil agent treatment tank containing the process liquid containing an oil agent and water, and an oil agent It is preferable from the industrial aspect to attach the slag.
As for the adhesion amount of the oil agent of the carbon fiber precursor fiber bundle 1 by an oil agent process, 0.1-3.0 mass% is preferable with respect to the dried carbon fiber precursor fiber bundle 1. FIG. As a method of adjusting the adhesion amount of the oil agent, for example, the oil agent concentration in the treatment liquid can be adjusted, or the treatment liquid immersed in the carbon fiber precursor fiber bundle 1 can be adjusted by squeezing with a nip roll or the like.

油剤処理された炭素繊維前駆体繊維束１は乾燥された後、本発明の耐炎化炉１０または２０に送入され、耐炎化処理される。
炭素繊維前駆体繊維束１の耐炎化条件としては、２００〜３００℃の熱風中、緊張あるいは延伸条件下で、好ましくは耐炎化処理後の耐炎化繊維の密度が１.３０ｇ／ｃｍ^３〜１.４０ｇ／ｃｍ^３になるまで耐炎化処理するのが好ましい。１.３０ｇ／ｃｍ^３未満では耐炎化が不充分であり、耐炎化処理後に行われる前炭素化処理や炭素化処理の際に単糸間の融着を生じやすく、得られる炭素繊維束の品質が低下する。また、耐炎化繊維の密度が１.４０ｇ／ｃｍ^３を超えると、前炭素化処理や炭素化処理の際に、耐炎化繊維束に酸素が過度に導入され、最終的な炭素繊維の内部構造が緻密にならず、得られる炭素繊維束の品質が低下する。 The carbon fiber precursor fiber bundle 1 treated with the oil agent is dried and then fed into the flameproofing furnace 10 or 20 of the present invention to be flameproofed.
As the flameproofing conditions of the carbon fiber precursor fiber bundle 1, the density of the flameproofed fiber after the flameproofing treatment is preferably 1.30 g / cm ³ to 1 in a hot air at 200 to 300 ° C. under tension or stretching conditions. It is preferable to carry out the flameproofing treatment until it becomes .40 g / cm ³ . If it is less than 1.30 g / cm ³ , the flame resistance is insufficient, and the pre-carbonization treatment or the carbonization treatment performed after the flame resistance treatment tends to cause fusion between single yarns, and the quality of the obtained carbon fiber bundle. Decreases. Further, when the density of the flameproof fiber exceeds 1.40 g / cm ³ , oxygen is excessively introduced into the flameproof fiber bundle during the pre-carbonization treatment or carbonization treatment, and the final internal structure of the carbon fiber is obtained. Does not become dense, and the quality of the obtained carbon fiber bundle is deteriorated.

一方、耐炎化繊維束を焼成加工して難燃性織布等の耐熱製品を製造する場合は、それに用いる耐炎化繊維束の密度は１.４０ｇ／ｃｍ^３を超えていても構わない。ただし、１.５０ｇ／ｃｍ^３を超えると、耐炎化繊維束を焼成加工する時間が長くなるため、経済的に好ましくない。 On the other hand, when a heat-resistant product such as a flame-retardant woven fabric is produced by firing the flame-resistant fiber bundle, the density of the flame-resistant fiber bundle used therefor may exceed 1.40 g / cm ³ . However, if it exceeds 1.50 g / cm ³ , the time for firing the flameproof fiber bundle becomes longer, which is not economically preferable.

本発明の耐炎化炉１０または２０の熱処理室２内を満たす熱風（酸化性気体）としては、酸素を含む気体であれば特に制限されないが、工業生産の面からすると、空気を用いるのが経済面、安全面で特に優れている。また、酸化能力を調整する目的で、熱風中の酸素濃度を変更することもできる。   The hot air (oxidizing gas) that fills the heat treatment chamber 2 of the flameproofing furnace 10 or 20 of the present invention is not particularly limited as long as it contains oxygen, but from the viewpoint of industrial production, it is economical to use air. It is particularly excellent in terms of safety and safety. Further, the oxygen concentration in the hot air can be changed for the purpose of adjusting the oxidation ability.

耐炎化処理によって得られた耐炎化繊維束は、次いで炭素化炉に送入されて前炭素化処理される。前炭素化処理における最高温度は５５０〜８００℃が好ましい。
３００〜５００℃の温度領域においては、５００℃／分以下の昇温速度で前炭素化処理を行うのが、炭素繊維の機械的特性を向上させるために好ましい。より好ましくは３００℃／分以下である。
炭素化炉内を満たす不活性雰囲気としては、窒素、アルゴン、ヘリウム等の公知の不活性雰囲気を採用できるが、経済性の面から窒素が好ましい。 The flame-resistant fiber bundle obtained by the flame resistance treatment is then fed into a carbonization furnace and pre-carbonized. The maximum temperature in the pre-carbonization treatment is preferably 550 to 800 ° C.
In the temperature range of 300 to 500 ° C., it is preferable to perform the pre-carbonization treatment at a heating rate of 500 ° C./min or less in order to improve the mechanical properties of the carbon fiber. More preferably, it is 300 degrees C / min or less.
As the inert atmosphere that fills the carbonization furnace, a known inert atmosphere such as nitrogen, argon, or helium can be adopted, but nitrogen is preferable from the viewpoint of economy.

前炭素化処理によって得られた前炭素化繊維束は、次いで炭素化炉に送入されて炭素化処理される。炭素繊維の機械的特性を向上させるためには、１２００〜３０００℃の不活性雰囲気中、１０００〜１２００℃の温度領域において、５００℃／分以下の昇温速度で炭素化処理するのが好ましい。
不活性雰囲気については、窒素、アルゴン、ヘリウム等の公知の不活性雰囲気を採用できるが、経済性の面から窒素が好ましい。 The pre-carbonized fiber bundle obtained by the pre-carbonization treatment is then fed into a carbonization furnace and carbonized. In order to improve the mechanical properties of the carbon fiber, it is preferable to perform carbonization treatment at a temperature increase rate of 500 ° C./min or less in a temperature range of 1000 to 1200 ° C. in an inert atmosphere of 1200 to 3000 ° C.
As the inert atmosphere, a known inert atmosphere such as nitrogen, argon, helium or the like can be adopted, but nitrogen is preferable from the viewpoint of economy.

このようにして得られた炭素繊維束には、必要に応じて、炭素繊維束の取り扱い性や、マトリックス樹脂との親和性を向上させるため、サイジング剤を付与してもよい。サイジング剤の種類としては、所望の特性を得ることができれば特に限定されないが、例えば、エポキシ樹脂、ポリエーテル樹脂、エポキシ変性ポリウレタン樹脂、ポリエステル樹脂を主成分としたサイジング剤が挙げられる。サイジング剤の付与は公知の方法を用いることができる。
さらに炭素繊維束には、必要に応じて、繊維強化複合材料マトリックス樹脂との親和性及び接着性の向上を目的とした電解酸化処理や酸化処理を行ってもよい。 The carbon fiber bundle obtained in this manner may be provided with a sizing agent as necessary in order to improve the handleability of the carbon fiber bundle and the affinity with the matrix resin. The type of the sizing agent is not particularly limited as long as desired characteristics can be obtained, and examples thereof include a sizing agent mainly composed of an epoxy resin, a polyether resin, an epoxy-modified polyurethane resin, and a polyester resin. A known method can be used to apply the sizing agent.
Further, the carbon fiber bundle may be subjected to electrolytic oxidation treatment or oxidation treatment for the purpose of improving the affinity and adhesiveness with the fiber reinforced composite material matrix resin as necessary.

本発明よれば、熱風循環系に存在する粉塵を効率的に除去できるので、耐炎化炉１０の長期的な連続稼動が可能になる。これにより、粉塵除去に要するメンテナンス費用が低減でき、かつ耐炎化繊維の生産性が向上できる。また、熱処理室２内の粉塵の滞留が低減されるため、糸切れのない耐炎化繊維を得ることができ、ひいては高品質な炭素繊維を製造が可能となる。   According to the present invention, dust existing in the hot air circulation system can be efficiently removed, so that the flameproof furnace 10 can be continuously operated for a long time. Thereby, the maintenance cost required for dust removal can be reduced, and the productivity of the flameproof fiber can be improved. Moreover, since the accumulation of dust in the heat treatment chamber 2 is reduced, flameproof fibers without yarn breakage can be obtained, and as a result, high-quality carbon fibers can be produced.

以下に、実施例によって本発明をさらに具体的に説明するが、本発明はこれらによって限定されない。なお、実施例の評価方法は次の方法に拠った。
＜含有シリコーン量（Ｓｉ付着量）測定＞
ポリアクリロニトリル系繊維束からなる炭素繊維前駆体繊維束１及び耐炎化繊維束の測定サンプルを、縦２ｃｍ、横４ｃｍ、幅０．５ｃｍのアクリル樹脂製板に隙間無く横方向に均一に巻いてから、通常の蛍光Ｘ線分析方法により蛍光Ｘ線強度を測定し、含有シリコーン量、すなわちＳｉ付着量（蛍光Ｘ線強度、単位：ｃｐｓ）を求めた。なお、測定サンプルの巻き作業は、測定サンプルが全て同一の巻き長になるように行った。なお、蛍光Ｘ線強度の測定器には、蛍光Ｘ線分析装置（リガク社製、型式ＺＳＸ１００ｅ）を用いた。
炭素繊維前駆体繊維束１及び耐炎化繊維束への油剤の付着斑、あるいは測定誤差等を考慮し、測定時間毎のサンプルの測定数はｎ＝１０とし、その平均値を求めてＳｉ付着量とした。
前記測定によって求められた炭素繊維前駆体繊維束１のＳｉ付着量をＡ１、また、前記測定によって得られた耐炎化繊維束のＳｉ付着量をＡ２とし、下記式（２）で計算して得られた値をＳｉ残存率とした。
Ｓｉ残存率（％）＝Ａ２／Ａ１×１００ ・・・・式（２） Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto. In addition, the evaluation method of the Example was based on the following method.
<Measurement of contained silicone amount (Si adhesion amount)>
After the carbon fiber precursor fiber bundle 1 and the flame-resistant fiber bundle made of polyacrylonitrile fiber bundle are uniformly wound in the horizontal direction without any gaps on an acrylic resin plate having a length of 2 cm, a width of 4 cm, and a width of 0.5 cm. Then, the fluorescent X-ray intensity was measured by an ordinary fluorescent X-ray analysis method, and the amount of silicone contained, that is, the Si adhesion amount (fluorescent X-ray intensity, unit: cps) was determined. The measurement sample was wound so that all the measurement samples had the same winding length. Note that a fluorescent X-ray analyzer (model ZSX100e, manufactured by Rigaku Corporation) was used as a measuring device for fluorescent X-ray intensity.
Considering the adhesion spot of the oil agent on the carbon fiber precursor fiber bundle 1 and the flameproof fiber bundle, or measurement error, the number of samples measured per measurement time is set to n = 10, and the average value is obtained to determine the amount of Si attached. It was.
Obtained by calculating the following formula (2), assuming that the Si adhesion amount of the carbon fiber precursor fiber bundle 1 obtained by the measurement is A1, and the Si adhesion amount of the flame-resistant fiber bundle obtained by the measurement is A2. The obtained value was defined as the Si residual ratio.
Si residual ratio (%) = A2 / A1 × 100 (2)

アクリロニトリル共重合体を、共重合体濃度が２１質量％となるようにジメチルアセトアミドに溶解して紡糸原液とした。この紡糸原液を２４０００ホールのノズルを用いて濃度７０質量％、温度３５℃のジメチルアセトアミド水混合溶媒溶液中に吐出して湿式紡糸した。次に、凝固繊維を空中延伸にて１．５倍の延伸を行った後、さらに沸水中で浴中延伸して３倍の延伸を行い、同時に洗浄及び脱溶剤も行った。
その後、油剤の水分散液が入った油剤処理槽に凝固繊維を浸漬し、油剤を１．０質量％付着させた後、１４０℃の加熱ローラにて乾燥し、加圧水蒸気中にて３倍延伸し、単繊維繊度１．２ｄｔｅｘのポリアクリロニトリル系繊維束からなる炭素繊維前駆体繊維束１を得た。炭素繊維前駆体繊維束１のＳｉ付着量は、５０８０ｃｐｓであった。
なお、前記で用いた油剤の水分散液は、以下の原料と方法を用いて調製された。まず、油剤主剤には両末端アミノ変性シリコーン（２５℃での粘度５００ｃＳｔ、アミノ当量５７００ｇ／モル）、油剤乳化物にはノニオン系乳化剤（ポリオキシエチレンステアリルエーテル［エチレンオキサイド：１２モル、ＨＬＢ：１３．９］）を用い、これらの混合物にイオン交換水を加え、ホモミキサーで乳化し、さらに乳化粒径が０．３μｍになるよう高圧ホモジナイザーで圧力を調整して二次乳化を行うことで調製して、油剤の水分散液とした。 The acrylonitrile copolymer was dissolved in dimethylacetamide so that the copolymer concentration was 21% by mass to obtain a spinning dope. This spinning dope was discharged into a dimethylacetamide water mixed solvent solution having a concentration of 70% by mass and a temperature of 35 ° C. using a 24000 hole nozzle, and was wet-spun. Next, the coagulated fiber was stretched 1.5 times by air stretching, and further stretched in a bath in boiling water to stretch 3 times, and at the same time, washing and solvent removal were performed.
Thereafter, the coagulated fiber is dipped in an oil agent treatment tank containing an aqueous dispersion of the oil agent, and 1.0 mass% of the oil agent is attached, and then dried with a heating roller at 140 ° C., and stretched three times in pressurized steam. Thus, a carbon fiber precursor fiber bundle 1 composed of a polyacrylonitrile fiber bundle having a single fiber fineness of 1.2 dtex was obtained. The Si adhesion amount of the carbon fiber precursor fiber bundle 1 was 5080 cps.
The aqueous dispersion of the oil used above was prepared using the following raw materials and method. First, an oil-based main agent is an amino-modified silicone (both ends at 25 ° C., viscosity 500 cSt, amino equivalent 5700 g / mol), and an oil-based emulsion is a nonionic emulsifier (polyoxyethylene stearyl ether [ethylene oxide: 12 mol, HLB: 13). 9]), ion-exchanged water is added to these mixtures, emulsified with a homomixer, and further subjected to secondary emulsification by adjusting the pressure with a high-pressure homogenizer so that the emulsified particle size becomes 0.3 μm. Thus, an aqueous dispersion of the oil was prepared.

炭素繊維前駆体繊維束１を空気中２４０℃で２４、４８、７２ｈｒと処理時間を変えて耐炎化処理を行ったところ、密度が１．６ｇ／ｃｍ^３で変化しなくなった。よって反応停止時の密度は１．６ｇ／ｃｍ^３である。 When the carbon fiber precursor fiber bundle 1 was subjected to flameproofing treatment at 240 ° C. in air for 24, 48, and 72 hours with different treatment times, the density did not change at 1.6 g / cm ³ . Accordingly density during quenching is 1.6 g / cm ^3.

この炭素繊維前駆体繊維束１を、４台の耐炎化炉に連続して送入し、耐炎化処理を４回に分けて行った。
まず、１回目の耐炎化処理として、図２に示す本発明の耐炎化炉２０を用いた。熱風吹出口４、４ａ及び熱風排出口５，５ａには、繊維束に均一に酸化性雰囲気ガスが接触するよう、孔直径４ｍｍで開口率３０％の多孔板を設置した。熱処理室２内の温度は２３０℃、風速は３ｍ／ｓに設定し、炭素繊維前駆体繊維束１を１５分間かけて緊張下に耐炎化処理した。なお、炭素繊維前駆体繊維束１の初期走行域に相当する熱処理区画２ａ内の風速は熱処理室２の５０％である１．５ｍ／ｓ、走行時間は３．８分であった。 This carbon fiber precursor fiber bundle 1 was continuously fed into four flameproofing furnaces, and the flameproofing treatment was divided into four times.
First, the flameproofing furnace 20 of the present invention shown in FIG. 2 was used as the first flameproofing process. At the hot air outlets 4 and 4a and the hot air outlets 5 and 5a, a perforated plate having a hole diameter of 4 mm and an aperture ratio of 30% was installed so that the oxidizing atmosphere gas was in uniform contact with the fiber bundle. The temperature in the heat treatment chamber 2 was set to 230 ° C., the wind speed was set to 3 m / s, and the carbon fiber precursor fiber bundle 1 was flameproofed under tension over 15 minutes. The wind speed in the heat treatment section 2a corresponding to the initial travel region of the carbon fiber precursor fiber bundle 1 was 1.5 m / s, which is 50% of the heat treatment chamber 2, and the travel time was 3.8 minutes.

１回目の耐炎化処理で耐炎化処理された炭素繊維前駆体繊維１を、次に、図３に示す構造の従来の耐炎化炉３０に送入し、２〜４回目の耐炎化処理を行った。耐炎化炉３０の熱処理室２内には、耐炎化炉２０と同様の多孔板を設置し、設定温度をそれぞれ２３５、２４３、２５４とし、炭素繊維前駆体繊維束１を各１５分間かけて、緊張下に耐炎化処理した。
初期走行域通過後の繊維束の密度は１．１９ｇ／ｃｍ^３、４回の耐炎化処理によって得られた耐炎化繊維束は、１.３５ｇ／ｃｍ^３の耐炎化密度を有していた。初期走行域での耐炎化の進行度は２．５であった。なお、図３の耐炎化炉３０に付した各構成の符号において、図１の耐炎化炉１０の各構成と同様の構成には、図１と同じ符号を付して、説明を省略する。 Next, the carbon fiber precursor fiber 1 subjected to the flame resistance treatment in the first flame resistance treatment is fed into the conventional flame resistance furnace 30 having the structure shown in FIG. 3 and subjected to the flame resistance treatment for the second to fourth times. It was. In the heat treatment chamber 2 of the flameproofing furnace 30, a porous plate similar to the flameproofing furnace 20 is installed, the set temperatures are set to 235, 243, and 254, respectively, and the carbon fiber precursor fiber bundle 1 is taken for 15 minutes each, Flameproofing was applied under tension.
The density of the fiber bundle after passing through the initial traveling region was 1.19 g / cm ³ , and the flame-resistant fiber bundle obtained by the four times flame-proofing treatment had a flame-resistant density of 1.35 g / cm ³ . The progress of flame resistance in the initial running region was 2.5. In addition, in the code | symbol of each structure attached | subjected to the flameproofing furnace 30 of FIG. 3, the code | symbol same as each structure of the flameproofing furnace 10 of FIG. 1 is attached | subjected, and description is abbreviate | omitted.

耐炎化炉２０の初期走行域において、炭素繊維前駆体繊維１の供給速度を変えて耐炎化処理を行った際の炭素繊維前駆体繊維束１の時間経過毎のＳｉ残存率を図４に示す。炭素繊維前駆体繊維１に付着しているＳｉ残存量は、耐炎化炉２０への送入から０．５分の間に急激に低下し、０．５分後のＳｉ残存率は９３．９％、２分後では９３．５％、１０分後では９１．２％であった。なお、耐炎化繊維束のＳｉ残存率は、８７．０％であった。これらの情報から、耐炎化進行度と残存率の相関(近似)を図５に示す。シリコーン系油剤からの揮発物は、その大部分が耐炎化炉への送入後の初期に発生していることが確認された。本実施例における耐炎化炉２０の熱処理室２ａの滞在時間は３．８分だったので、大部分の揮発物は、排出手段によって熱風循環系の外に排出されたと推察された。
２週間にわたり前記の耐炎化処理を継続したが、耐炎化炉２０及び従来の耐炎化炉３０において、多孔板の目詰まりは発生しなかった。 FIG. 4 shows the Si residual rate of the carbon fiber precursor fiber bundle 1 for each time passage when the flame resistance treatment is performed by changing the supply speed of the carbon fiber precursor fiber 1 in the initial running region of the flameproofing furnace 20. . The remaining amount of Si adhering to the carbon fiber precursor fiber 1 rapidly decreases in 0.5 minutes after being fed into the flameproofing furnace 20, and the remaining Si rate after 0.5 minutes is 93.9. %, 93.5% after 2 minutes, and 91.2% after 10 minutes. Note that the Si residual ratio of the flameproofed fiber bundle was 87.0%. From these pieces of information, the correlation (approximation) between the progress of flame resistance and the remaining rate is shown in FIG. It was confirmed that most of the volatiles from the silicone-based oil were generated in the initial stage after being fed into the flameproofing furnace. Since the residence time of the heat treatment chamber 2a of the flameproofing furnace 20 in this example was 3.8 minutes, it was assumed that most of the volatiles were discharged out of the hot air circulation system by the discharge means.
Although the above flameproofing treatment was continued for 2 weeks, clogging of the perforated plate did not occur in the flameproofing furnace 20 and the conventional flameproofing furnace 30.

１回目の耐炎化処理において、熱処理区画２ａ内の風速は熱処理室２の約１７％である０．５ｍ／ｓとした以外は、実施例１と同様にして、密度１.３５ｇ／ｃｍ^３の耐炎化繊維束を得た。初期走行域通過後の繊維束の密度は１．１８２ｇ／ｃｍ^３、耐炎化の進行度は０．５であった。耐炎化炉２０の初期走行域において、炭素繊維前駆体繊維１の供給速度を変えて耐炎化処理を行った際の炭素繊維前駆体繊維束１の時間経過毎のＳｉ付着率を図６に示す。炭素繊維前駆体繊維１に付着しているＳｉ付着量は、耐炎化炉２０への送入から２分の間に急激に低下し、１分後のＳｉ残存率は９７．５％、２分後では９３．８％、５分後では９３．７％であった。これらの情報から、耐炎化進行度と残存率の相関(近似)を図７に示す。実施例１と同様、シリコーン系油剤からの揮発物は、その大部分が耐炎化炉への送入後の初期に発生していることが確認され、２週間にわたり前記の耐炎化処理を継続したが、多孔板の目詰まりは発生しなかった。 In the first flameproofing treatment, a density of 1.35 g / cm ³ was obtained in the same manner as in Example 1 except that the wind speed in the heat treatment section 2a was 0.5 m / s, which is about 17% of the heat treatment chamber 2. A flame resistant fiber bundle was obtained. The density of the fiber bundle after passing through the initial traveling region was 1.182 g / cm ³ , and the progress of flame resistance was 0.5. FIG. 6 shows the Si adhesion rate for each time passage of the carbon fiber precursor fiber bundle 1 when the flame resistance treatment is performed by changing the supply rate of the carbon fiber precursor fiber 1 in the initial running region of the flameproofing furnace 20. . The amount of Si adhering to the carbon fiber precursor fiber 1 sharply decreases in 2 minutes after feeding into the flameproofing furnace 20, and the Si remaining rate after 1 minute is 97.5%, 2 minutes. After 93.8%, after 5 minutes it was 93.7%. From these pieces of information, the correlation (approximation) between the progress of flame resistance and the remaining rate is shown in FIG. As in Example 1, it was confirmed that most of the volatiles from the silicone-based oil were generated in the initial stage after being fed into the flame-proofing furnace, and the flame-proofing treatment was continued for 2 weeks. However, clogging of the perforated plate did not occur.

＜比較例１＞
１回目の耐炎化処理に図３の従来の耐炎化炉３０を用いたこと以外は、実施例１と同様にして、密度１.３５ｇ／ｃｍ^３の耐炎化繊維束を得た。また、得られた耐炎化繊維束のＳｉ残存率は８６．８％であった。
この状態にて耐炎化処理を継続したが、運転開始９日目になって、１回目の耐炎化処理に用いていた従来の耐炎化炉３０で、前駆体繊維１の糸切れが多発した。運転を停止して従来の耐炎化炉３０内を観察すると、熱処理室２に設けた多孔板が粉塵により目詰まりしていた。 <Comparative Example 1>
A flame-resistant fiber bundle having a density of 1.35 g / cm ³ was obtained in the same manner as in Example 1 except that the conventional flame-proofing furnace 30 of FIG. 3 was used for the first flame-proofing treatment. Moreover, Si residual ratio of the obtained flame-resistant fiber bundle was 86.8%.
In this state, the flameproofing treatment was continued. However, on the 9th day from the start of operation, yarn breakage of the precursor fiber 1 occurred frequently in the conventional flameproofing furnace 30 used for the first flameproofing treatment. When the operation was stopped and the inside of the conventional flameproofing furnace 30 was observed, the porous plate provided in the heat treatment chamber 2 was clogged with dust.

前記の実施例１、２及び比較例１によって、本発明の耐炎化炉２０は、シリコーン系油剤からの揮発物の大部分が熱風循環系の外に排出されるため、従来の耐炎化炉３０に比して熱処理室２内の粉塵の発生を抑制でき、これにより、耐炎化炉の長期的な連続稼動が可能であると評価された。 According to Examples 1 and 2 and Comparative Example 1 described above, the flameproofing furnace 20 of the present invention has a conventional flameproofing furnace 30 because most of the volatiles from the silicone oil are discharged out of the hot air circulation system. It was evaluated that the generation of dust in the heat treatment chamber 2 can be suppressed as compared with the above, and that the flameproofing furnace can be operated continuously for a long time.

本発明の耐炎化炉及び炭素繊維の製造方法によれば、熱エネルギーの損失が少ないという熱風循環方式の利点を有しながら、熱風循環方式の欠点である粉塵の滞留を低減できる。従って、耐炎化炉の清掃に伴うメンテナンス費用が低減でき、かつ耐炎化炉の長期的な連続稼動が可能になることで、耐炎化繊維束の生産効率を向上できる。
また、本発明の耐炎化炉は、熱風循環系内の粉塵の滞留を低減できるので、熱風吹出口の閉塞が起こりにくい。従って、本発明の耐炎化炉を用いた炭素繊維の製造方法によれば、熱風の循環が長期にわたり安定して行われるので、前駆体繊維束の糸切れを低減できる。また、粉塵が低減されるので、前駆体繊維束への粉塵の付着も低減される。ゆえに、高品質な炭素繊維を得ることができる。
複数の耐炎化炉を用いた炭素繊維の製造において、少なくとも最初の耐炎化処理を行う耐炎化炉に本発明の耐炎化炉を用いれば、前駆体繊維束から発生する揮発物を熱風循環系の外に排出できるため、最初の耐炎化炉及びそれ以降の耐炎化炉おける糸切れや発火を減少できる。これにより、高品質な耐炎化繊維を得ることができ、以って高品質な炭素繊維が製造できる。 According to the flameproofing furnace and the carbon fiber manufacturing method of the present invention, it is possible to reduce dust retention, which is a disadvantage of the hot air circulation system, while having the advantage of the hot air circulation system that there is little loss of thermal energy. Therefore, the maintenance cost accompanying the cleaning of the flameproofing furnace can be reduced, and the flameproofing furnace can be operated continuously for a long time, so that the production efficiency of the flameproofing fiber bundle can be improved.
Moreover, since the flameproofing furnace of the present invention can reduce the accumulation of dust in the hot air circulation system, the hot air outlet is not easily blocked. Therefore, according to the carbon fiber manufacturing method using the flameproofing furnace of the present invention, hot air is circulated stably over a long period of time, so that yarn breakage of the precursor fiber bundle can be reduced. Moreover, since dust is reduced, adhesion of dust to the precursor fiber bundle is also reduced. Therefore, a high quality carbon fiber can be obtained.
In the production of carbon fibers using a plurality of flameproofing furnaces, if the flameproofing furnace of the present invention is used in at least the first flameproofing furnace, the volatile matter generated from the precursor fiber bundle is removed from the hot air circulation system. Since it can discharge outside, yarn breakage and ignition in the first flameproofing furnace and the subsequent flameproofing furnaces can be reduced. Thereby, a high-quality flameproof fiber can be obtained, and thus a high-quality carbon fiber can be produced.

本発明の耐炎化炉を示す概略側面図である。It is a schematic side view which shows the flameproofing furnace of this invention. 本発明の別形態の耐炎化炉を示す概略側面図である。It is a schematic side view which shows the flameproofing furnace of another form of this invention. 従来の耐炎化炉を示す概略側面図である。It is a schematic side view which shows the conventional flameproofing furnace. 風速１．５ｍ／ｓにおける炭素繊維前駆体繊維束のＳｉ残存率と耐炎化処理時間との関係を示した図である。It is the figure which showed the relationship between Si residual rate of a carbon fiber precursor fiber bundle in wind speed 1.5m / s, and flameproofing treatment time. 初期走行域の風速１．５ｍ／ｓ条件時の耐炎化進行度と炭素繊維前駆体繊維束のＳｉ残存率との関係を示した図である。It is the figure which showed the relationship between the flameproofing progress degree at the time of the wind speed of 1.5 m / s of an initial travel area, and Si residual rate of a carbon fiber precursor fiber bundle. 風速０．５ｍ／ｓにおける炭素繊維前駆体繊維束のＳｉ残存率と耐炎化処理時間との関係を示した図である。It is the figure which showed the relationship between Si residual rate of the carbon fiber precursor fiber bundle in a wind speed of 0.5 m / s, and flameproofing treatment time. 初期走行域の風速０．５ｍ／ｓ条件時の耐炎化進行度と前駆体繊維束のＳｉ残存率との関係を示した図である。It is the figure which showed the relationship between the flameproofing progress degree at the time of the wind speed of 0.5 m / s of an initial travel area, and Si residual rate of a precursor fiber bundle.

符号の説明Explanation of symbols

１ 炭素繊維前駆体繊維束
２ 熱処理室
２ａ、２ｂ 熱処理区画
３ ガイドロール
４、４ａ 熱風吹出口
５、５ａ 熱風排出口
６ 加熱器
７ 送風器
８ 熱風循環路
９ 仕切り板
１０、２０ 耐炎化炉
１１ 排出路
１２、１６ 排気ファン
１３、１７ 排ガス燃焼装置
１４ 集塵装置
１５ 外気取り入れ口
１８、１９ ダンパー
３０ 従来の耐炎化炉 DESCRIPTION OF SYMBOLS 1 Carbon fiber precursor fiber bundle 2 Heat treatment chamber 2a, 2b Heat treatment section 3 Guide roll 4, 4a Hot air outlet 5, 5a Hot air outlet 6 Heater 7 Air blower 8 Hot air circulation path 9 Partition plate 10, 20 Flame resistance furnace 11 Exhaust passages 12 and 16 Exhaust fans 13 and 17 Exhaust gas combustion device 14 Dust collector 15 Outside air intake port 18 and 19 Damper 30 Conventional flameproofing furnace

Claims (2)

その内部で、炭素繊維前駆体繊維束を複数回走行させ、かつ熱風を吹き付けて耐炎化処理する熱処理室と、
前記熱処理室内の熱風を循環させる熱風循環路と、
初期走行域の熱風の風速を、その他走行域の風速の１０〜５０％に調整する調整機構と、
前記初期走行域を通過した熱風を、前記熱処理室と前記熱風循環路からなる熱風循環系の外に排出する排出路と、
を備えた耐炎化炉。 Inside, a heat treatment chamber for running the carbon fiber precursor fiber bundle a plurality of times and spraying hot air to make it flameproof,
A hot air circulation path for circulating hot air in the heat treatment chamber;
An adjustment mechanism for adjusting the wind speed of the hot air in the initial travel area to 10 to 50% of the wind speed in the other travel areas;
A discharge path for discharging the hot air that has passed through the initial traveling area out of the hot air circulation system including the heat treatment chamber and the hot air circulation path;
A flameproof furnace equipped with 熱処理室の内部で炭素繊維前駆体繊維束を複数回走行させ、かつ熱風を吹き付けて耐炎化処理を行う炭素繊維の製造方法であって、
初期走行域の熱風の風速を、その他走行域の風速の１０〜５０％とし、
前記その他走行域を通過した熱風を、熱風循環路を介して前記熱処理室の内部で循環させ、
前記初期走行域を通過した熱風を、前記熱処理室と前記熱風循環路からなる熱風循環系の外に排出する、
炭素繊維の製造方法。
A carbon fiber manufacturing method for running a carbon fiber precursor fiber bundle a plurality of times inside a heat treatment chamber and performing a flame resistance treatment by blowing hot air,
The wind speed of the hot air in the initial travel area is 10-50% of the wind speed in the other travel areas,
The hot air that has passed through the other traveling area is circulated inside the heat treatment chamber via a hot air circulation path,
The hot air that has passed through the initial traveling area is discharged out of the hot air circulation system that includes the heat treatment chamber and the hot air circulation path.
A method for producing carbon fiber.

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