JP3891955B2 - Paper machine and paper making method - Google Patents

Description

【００４０】
この式（１）において、上下差圧ΔＰ，湿紙脱水抵抗係数Ｒ_mat，ワイヤ脱水抵抗係数Ｒ_wが一定であるとし、脱水速度ｖと水粘度μとの関係に着目すると、脱水速度ｖは水粘度μと反比例の関係にある。また、水粘度μと湿紙温度との間には、湿紙温度が高くなると水粘度μは小さくなるという関係がある。つまり、湿紙温度が高くなると脱水速度ｖは大きくなるという関係がある。
【００４１】
通常、このダルシー則に従って、加熱蒸気により湿紙１は昇温されるため脱水速度が大きくなり脱水率が大きくなっていくが、これと同時に、原料濃度が増加するに従って脱水抵抗が増加するため、図３に示すような山なりの特性となり、蒸気供給状態に対応した最も効率のよい原料濃度が存在するのである。
【００４２】
したがって、脱水率を向上させるには、このような特性を考慮し、湿紙１の原料濃度に応じて最適な蒸気供給量を設定することが好ましい。このため、本抄紙機には、図１に示すように、蒸気ボックス６上流側近傍に、且つ、湿紙１幅方向において各蒸気供給室６ｅの位置に対応する位置（即ち、湿紙１の加熱対象箇所）に、湿紙１の水分率〔原料濃度に対応する，原料濃度（％）＝１００−水分率（％）〕を検出する水分率センサ（原料濃度検出手段）１３が設けられている（図１では１つのみ示す）。
【００４３】
そして、コントローラ１２は、各蒸気供給室６ｅを通過する湿紙１の温度が目標湿紙温度（湿紙１の原料濃度に対応するように予め設定された目標温度）になるように、各水分率センサ１３からの検出情報に基づいて、各バルブ１１の開閉動作を調整し各蒸気供給室６ｅの蒸気供給状態をリアルタイムで制御するようになっている。例えば、ある地点に蒸気供給室６ｅが配置され、この地点に進入する湿紙１の基準原料濃度が１２％であるものとして、もし水分率センサ１３により湿紙１の原料濃度が１０％であると検出されたら、コントローラ１２は蒸気供給量を増加させるようにバルブ１１を制御し、もし水分率センサ１３により湿紙１の原料濃度が１４％であると検出されたら、コントローラ１２は蒸気供給量を低減させるようにバルブ１１を制御する。
【００４４】
また、蒸気ボックス６内及びサクションボックス７内の各分割領域単位で蒸気の噴射状態及び蒸気の吸引状態を調整することができるので、湿紙１幅方向における脱水調整を容易に行なうことができる。
【００４５】
さらに、ワイヤ３ａを介して湿紙１に蒸気を供給するので、蒸気ボックス６の先端開口部６ｇ周縁と湿紙１とが接触して湿紙１が破壊されてしまうことはなく、また、高温の蒸気が湿紙１に直接接触することにより生じるパルプの変質や変色を防止することができる。つまり、従来のような湿紙１に直接蒸気を吹き付ける構成の場合、湿紙１に損傷を与えないように蒸気ボックス６と湿紙１との間に隙間を設ける必要があり蒸気放出が多大であったが、本抄紙機では湿紙１の両面をワイヤ３ａ，３ｂで支持するツインワイヤを用いているため、蒸気ボックス６をワイヤに接触させることで湿紙１に損傷を与えないようにして上記の隙間をなくすことができ、従来に比べて蒸気放出量を抑制できる。すなわち、蒸気の損失を防止でき、供給蒸気を効率良く利用することができる。
【００４６】
また、蒸気ボックス６のシール部材６ｃにより蒸気ボックス６内の密閉性が確保されるので、蒸気ボックス６の内部から外部への蒸気放出をさらに抑制することができる。
【００４７】
さらに、従来は、湿紙１内部に蒸気を浸透させることにより湿紙１を昇温して脱水する点に着目しているため、蒸気が浸透しやすい状態、即ち、フォーマ最終部の湿紙１の「脱水完了前」であって湿紙１が多孔質の状態又は空隙が形成された状態となる位置に蒸気ボックス６０及びサクションボックス７０〔図８（ａ），（ｂ）参照〕を設置する必要があった。一方、本抄紙機では、サクションボックス７の吸引作用により、湿紙１表面付近で凝縮した高温水と湿紙１内部の水分とを置換することで湿紙１を昇温して脱水する点についても着目しているため、従来のように必ずしも湿紙１内部に蒸気を浸透させる必要がない。
【００４８】
つまり、従来は蒸気ボックスを脱水完了前の位置（即ち、フォーマ出口付近）に設置しなければならなかったのに対して、本発明によれば、より上流側に設置することが可能である。これにより、フォーマにおける湿紙１の脱水を上流側から促進することが可能になる。しかも、本抄紙機では、上述のように湿紙１の原料濃度状態に応じて最適な蒸気供給を行なうので、加熱脱水効率を高めることができる。したがって、フォーマにおける脱水を極めて効率良く行なうことが可能になり、ひいてはフォーマのコンパクト化が可能となり、フォーマの設置スペースを縮小できる効果もある。
【００４９】
また、本抄紙機の蒸気凝縮による熱伝達効率は、従来の蒸気浸透による熱伝達効率の約２５倍であり、従来と比べると非常に高効率である。したがって、従来は湿紙１の昇温が不十分であったためサクションボックス７０下流側にサクションボックス９を設置したとしても高い脱水効果は得られないが、本抄紙機では湿紙１が十分に昇温されているため、サクションボックス７下流側のサクションロール８やサクションボックス１４により高い脱水効果が得られ、湿紙１の脱水を促進することが可能である。
【００５０】
なお、本実施形態では蒸気ボックス６及びサクションボックス７の内部空間を分割して各分割領域単位で蒸気の噴射状態及び蒸気の吸引状態の調整を行なう構成としたが、湿紙１幅方向における原料濃度差を無視できる場合にはこれらの内部空間を分割しない（即ち、仕切壁６ｄ，７ｄを設けない）構成としてもよい。また、この場合、各水分率センサ１３から代表原料濃度（例えば湿紙の幅方向中央部）を得て、この代表原料濃度に基づいて目標湿紙温度まで昇温するのに必要な蒸気供給状態を設定するようにしてもよい。あるいは、湿紙１幅方向において１箇所（例えば湿紙１の幅方向中央部）のみに水分率センサ１３を設置し、この水分率センサ１３から得られる原料濃度に基づいて目標湿紙温度まで昇温するのに必要な蒸気供給状態を設定するようにしてもよい。
【００５１】
さらに、本実施形態では、水分率センサ１３からの検出情報に基づいてコントローラ１２によりバルブ１１の開閉動作を自動調整するように構成したが、水分率センサ１３からの検出情報に基づいてバルブ開閉動作を作業者が手動で行なうようにしてもよい。
また、本実施形態では、蒸気ボックス６及びサクションボックス７を、紙層を形成するフォーマにそなえる構成としたが、フォーマ下流側のプレスパート（フォーマで紙層形成された紙原料層を加圧して水分をさらに脱水するパート）にそなえてももちろんよい。
【００５２】
〔２〕第２実施形態
次に、本発明の第２実施形態としての抄紙機について説明する。
図４に示すように、本抄紙機は、第１実施形態の構成に加えて、サクションボックス７下流側の近接した位置にさらにもう１つのサクションボックス７Ａを備えて構成されている。
【００５３】
第１実施形態でも説明したように、蒸気ボックス６内では昇温過程が進行中であり、蒸気ボックス６内に進入した湿紙１は蒸気ボックス６内で次第に昇温されるが湿紙１全体が昇温されるまでには遅れが発生する。そこで、本抄紙機では、蒸気ボックス６内で昇温され脱水効果が高くなった状態の湿紙１を、サクションボックス７Ａによりさらに脱水するようになっている。また、サクションボックス７Ａは、脱水効果が高くなった状態の湿紙１を吸引するので、サクションボックス７の吸引力と等しくてもさらなる脱水を行なうことが可能であるが、サクションボックス７Ａの吸引力をサクションボックス７の吸引力よりも大きく設定することが好ましい。これにより、より効率良く脱水することができ、脱水率を向上させることができる。
【００５４】
〔３〕第３実施形態
次に、本発明の第３実施形態としての抄紙機について説明する。
図５に示すように、本抄紙機は、第１実施形態の構成において、サクションボックス７の下流側端部が、蒸気ボックス６の下流側端部よりも下流側にくるように配置されて構成されている。
【００５５】
上述したように、蒸気ボックス６で湿紙１全体が昇温されるまでには遅れが発生するため、サクションボックス７を下流側へずらして配置することで、より効率良く湿紙１を脱水することができ、脱水率をより向上させることができる。
なお、本実施形態では、第１実施形態に係るサクションボックス７を下流側へ所定距離だけずらして配置する構成としたが、第１実施形態に係るサクションボックス７の上流側端部はそのままの位置で固定し、サクションボックス７の下流側端部だけを蒸気ボックス６の下流側端部よりも下流側に位置するように構成してもよい。
【００５６】
〔４〕第４実施形態
次に、本発明の第４実施形態としての抄紙機について説明する。
図６に示すように、本抄紙機は、第１実施形態の構成において、蒸気ボックス６上流側端部の近傍に、上流側に向けて気体を噴射する気体噴射装置（シール手段）１４を備えて構成されている。また、この気体噴射装置１４が、上流側に向けて湿紙に対する噴射角θを約１５〜４０°として気体を噴射することが好ましい。
【００５７】
これにより、伴流空気の蒸気ボックス６内への進入をより確実に抑制することができる。なお、この気体噴射装置１４により伴流空気を十分に抑制できる場合は、蒸気ボックス６上流側のシール部材６ｃはなくてもよい。
【００５８】
〔５〕第５実施形態
次に、本発明の第５実施形態としての抄紙機について説明する。
図７に示すように、本抄紙機は、第１実施形態に係る蒸気ボックス６及びサクションボックス７のユニットを２組備えて構成されている。具体的には、蒸気ボックス６（第１の加熱手段）６及びサクションボックス７のユニットと、蒸気ボックス（第２の加熱手段）６′及びサクションボックス７′とを設け、また、蒸気ボックス６により湿紙１の一面側に蒸気を供給するとともに、蒸気ボックス６′により湿紙１の他面側にも蒸気を供給する構成とする。これにより、湿紙１の両面を均一に脱水することができ、表裏差の少ない両面均一な製品を製造することが可能となる。
【００５９】
〔６〕その他
以上、本発明の実施形態について説明したが、本発明は上記の実施形態に限定されるものではなく、本発明の趣旨を逸脱しない範囲で種々変形して実施することができる。
【００６０】
一般に、蒸気ボックス６の設置位置は設計上予め決められることになるが、この設置位置における湿紙１の原料濃度（基準原料濃度）も設計段階で予測できるため、抄紙機では、この基準原料濃度に対応する目標湿紙温度となるように蒸気供給が行なわれればよい。本実施形態では、水分率センサ１３により実際の湿紙１の原料濃度状態を検出し、蒸気ボックス６を通過する湿紙１の原料濃度が上記の基準原料濃度とずれが生じた場合、このずれを補正するためにフィードバク制御により蒸気ボックス６の蒸気供給量を調整するように構成したが、このような原料濃度のずれがほとんど無視できる場合、水分率センサ１３を設けずに、オープンループで常に一定の蒸気を供給するように構成してもよい。
【００６１】
また、湿紙１の温度を検出する手段を設け、この検出情報に基づくフィードバック制御により、湿紙１が目標湿紙温度となるように蒸気供給を調整してもよい。このようにしても、効率良く湿紙１を昇温して脱水することが可能であり、脱水率を向上させることができる。
【００６２】
また、蒸気ボックス６の下流側に、高温空気を湿紙１に吹き付けて高温空気の衝突噴流により湿紙１を加熱する空気噴流式加熱手段を設けてもよい。このように構成することで、蒸気ボックス６で昇温状態となった湿紙１をさらに昇温することができ、サクションロール８やサクションボックス９等による脱水効率を向上させることが可能となる。
【００６３】
さらに、蒸気ボックス６は湿紙１の水分率が高い状態で用いると効果が高いため湿紙１の水分率が高いフォーマに設置するのが好ましいが、プレスパート上流部（入口付近）に設置してもよい。また、空気噴流式加熱手段は、フォーマにおける湿紙１の水分率よりも低い状態に用いると効果が高いためフォーマよりも湿紙１の水分率が低いプレスパートに設置するのが好ましいが、フォーマ下流部（出口付近）に設置してもよい。
【００６４】
また、上記の実施形態では、蒸気ボックス６内の密閉性を確保するためにシール部材をワイヤ３ａに当接するように構成したが、蒸気ボックス６内の密閉性が確保できれば、シール部材６ｃをワイヤ３ａに近接するように構成してもよい。また、蒸気ボックス６の先端開口部６ｇがワイヤ３ａに当接又は近接することで蒸気ボックス６内の密閉性を確保できれば、特にシール部材６ｃを設けなくてもよい。
【００６５】
また、本発明は必ずしもツインワイヤに限定されるものではなく、紙原料層の片面だけを保持する片面長網であっても良い。
【００６６】
【発明の効果】
以上詳述したように、請求項１〜５記載の本発明の抄紙機によれば、水分を除去するパートで、調整手段により、紙原料層が予め設定された目標温度になるように、蒸気式加熱手段を通過する際の紙原料層の原料濃度状態に対応して蒸気式加熱手段による蒸気供給状態を調整するので、より効率良く紙原料層を昇温して脱水することが可能である。これにより、脱水率を向上させることができる。
また、蒸気式加熱手段には紙原料層への蒸気の供給を案内する蒸気ボックスが設けられ、該蒸気ボックスは、先端の開口部周縁をワイヤに当接又は近接させるようにして配置されているので、蒸気を効率良く紙原料層へ供給することができる。
さらに、第１のサクションボックスにより、紙原料層を挟んで蒸気ボックスと反対側に蒸気ボックスから噴射された蒸気を吸引するので、紙原料層表面で凝縮した高温水を紙原料層内部まで浸透させることができる。
加えて、蒸気ボックスの走行方向下流に、上記の第１のサクションボックスの他にさらに紙原料層の水分を吸収して除去する装置がそなえられているので、紙原料層全体が昇温した状態で脱水が可能となる。
特に、請求項４記載の本発明の抄紙機によれば、紙原料層の走行方向第２のサクションボックスの吸引力は、上流側の第１のサクションボックスの吸引力よりも大きく設定されているので、上流側の蒸気ボックスで昇温状態となった紙原料層の水分をさらに脱水することができ、脱水率をより向上させることができる。
【００６７】
請求項６記載の本発明の抄紙機によれば、蒸気ボックスの先端の開口部周縁には、蒸気ボックスの内外をシールするシール手段が設けられているので、蒸気をより効率良く紙原料層へ供給することができる。
【００６８】
請求項７記載の本発明の抄紙機によれば、シール手段は、蒸気ボックスの先端開口部周縁に取り付けられてワイヤに当接するシール部材であるので、蒸気ボックス内の密閉性を高めることができ、蒸気を紙原料層に効率良く供給することができる。
請求項８記載の本発明の抄紙機によれば、シール手段は、蒸気ボックスの先端開口部周縁よりも紙原料層の走行方向上流側に設けられ、気体を噴射することにより紙原料層の伴流の蒸気ボックス内への進入を抑制する気体噴射装置であるので、伴流空気の蒸気ボックス内への進入をより確実に抑制することができ、蒸気を紙原料層に効率良く供給することができる。
【００６９】
請求項９記載の本発明の抄紙機によれば、第１のサクションボックスの紙原料層の走行方向下流側端部は、蒸気ボックスの走行方向下流側端部よりも下流側に配置されているので、昇温状態の紙原料層の水分をさらに脱水することができ、脱水率をより向上させることができる。
【００７１】
請求項１０記載の本発明の抄紙機によれば、蒸気ボックス内が紙原料層の幅方向に複数に分割されると共に、第１のサクションボックス内が、蒸気ボックス内の分割と対応するように紙原料層の幅方向に複数に分割され、蒸気ボックス内及び第１のサクションボックス内の各分割領域単位で蒸気の噴射状態及び蒸気の吸引状態の調整が可能になっているので、各分割領域単位で脱水率を調整することができる。
【００７２】
請求項１１記載の本発明の抄紙機によれば、蒸気式加熱手段により供給される蒸気は、紙原料層に衝突噴流として作用することにより紙原料層を加熱するので、より効率良く紙原料層を昇温させて脱水することができる。
請求項１２記載の本発明の抄紙機によれば、調整手段を自動調整する制御手段をそなえているので、蒸気供給状態を自動で調整することができる。
【００７３】
請求項１３記載の本発明の抄紙機によれば、制御手段は、原料濃度検出手段による検出情報に基づいて、紙原料層が該目標温度まで昇温するように蒸気式加熱手段による蒸気供給状態を制御するので、最適な脱水効率が得られる蒸気供給状態に調整することができる。
請求項１４記載の本発明の抄紙機によれば、蒸気式加熱手段の設置箇所よりも紙原料層の走行方向下流側に、紙原料層を加熱する加熱手段として、紙原料層に高温空気を吹き付けて高温空気の衝突噴流により紙原料層を加熱する空気噴流式加熱手段がそなえられているので、蒸気式加熱手段において昇温状態となった紙原料層をさらに昇温して脱水することができ、脱水率をさらに向上させることができる。
【００７４】
請求項１５記載の本発明の抄紙機によれば、加熱手段として、紙原料層の一面から加熱を行なう第１の加熱手段と、紙原料層の他面から加熱を行なう第２の加熱手段とが、設けられているので、紙原料層の両面を均一に脱水することが可能である。
請求項１６記載の本発明の抄紙方法によれば、紙原料層が予め設定された目標温度になるように、加熱対象箇所における紙原料層に蒸気を供給し蒸気の凝縮作用により紙原料層を加熱して、その後、紙原料層から水分を吸収して除去するので、より効率良く紙原料層を昇温して脱水することが可能である。これにより、脱水率を向上させることができる。
【図面の簡単な説明】
【図１】本発明の第１実施形態としての抄紙機を模式的に示す構成図である。
【図２】本発明の第１実施形態に係る蒸気ボックス及びサクションボックスを模式的に示すもので、（ａ）は湿紙走行方向の断面図、（ｂ）は（ａ）のＡ−Ａ断面図である。
【図３】本発明の第１実施形態としての湿紙の原料濃度に対する脱水率（脱水促進効果）の変化を示すグラフである。
【図４】本発明の第２実施形態としての抄紙機を模式的に示す構成図である。
【図５】本発明の第３実施形態としての抄紙機を模式的に示す構成図である。
【図６】本発明の第４実施形態としての抄紙機を模式的に示す構成図である。
【図７】本発明の第５実施形態としての抄紙機を模式的に示す構成図である。
【図８】従来の抄紙機に係る蒸気ボックス及びサクションボックスを模式的に示すもので、（ａ）は湿紙走行方向の断面図、（ｂ）は（ａ）のＡ−Ａ断面図である。
【符号の説明】
１ 湿紙（紙原料層）
１ａ パルプ懸濁液（紙原料液）
２ ヘッドボックス
３ａ，３ｂ ワイヤ
４ フォーミングロール
５ ブレードシュー
６，６′，６０ 蒸気ボックス（蒸気式加熱手段）
６ａ 蒸気ボックス本体
６ｂ 保温体
６ｃ シール部材（シール手段）
６ｄ 仕切壁
６ｅ 蒸気供給室
６ｆ 蒸気導入口
６ｇ 先端開口部
７，７Ａ，７′，７０ サクションボックス
７ｄ 仕切壁
７ｅ 吸引室
７ｆ 吸引口
７ｇ 先端開口部
８ サクションロール
９ サクションボックス
１０ 蒸気発生源
１１ バルブ（調整手段）
１２ コントローラ（制御手段）
１３ 水分率センサ（原料濃度検出手段）
１４ 気体噴射装置（シール手段）[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a paper machine and a paper making method for performing paper making by removing moisture while running a paper raw material layer.
[0002]
[Prior art]
In general, in a paper machine, a pulp suspension (paper raw material liquid) sprayed from a head box is held in layers by a wire or the like, and moisture is removed while running the paper raw material layer (hereinafter also referred to as wet paper). Paper making is done.
Various dewatering methods have been developed for paper machines. For example, in Patent Document 1, as shown in FIG. 8A, a wet path is formed on a running path in a final part of a former (also referred to as a forming part or a paper layer forming part). A paper machine having a steam box 60 for supplying steam to the surface of the paper 1 is disclosed.
[0003]
In such a paper machine, the steam from the steam generation source 10 is supplied to the steam box 60 through the steam introduction pipe, and condensed by bringing the steam into contact with the wet paper 1 held on the wire 30 to transfer heat. To do.
In the final part of the former, the wet paper web 1 is considered to be in a state before completion of dehydration, that is, a state in which dehydration has progressed to form a void or a porous state. By sucking the lower surface of the wet paper 1 through the vapor, the vapor enters such voids and pores and penetrates into the wet paper 1. As a result, the latent heat of the steam is converted into sensible heat of water, the wet paper is heated, and the dehydration rate is improved.
[0004]
The dewatering rate of the wet paper web 1 running on the former is not uniform, and in general, the dewatering rate is lower at the center portion in the width direction of the wet paper paper 1 than at the left and right end portions in the width direction. Therefore, as shown in FIG. 8 (b), in order to bring a larger amount of steam into contact with the central portion in the width direction of the wet paper web 1 whose dehydration rate is relatively low than in the left and right sides in the width direction, A plurality of steam supply chambers 61 are formed in the width direction, and the valve 11 opening corresponding to each steam supply chamber 61 is appropriately operated, so that the steam supply chamber 61 located at the center in the width direction A technique for supplying a larger amount of steam than the steam in the steam supply chamber 61 located on the side has been developed.
[0005]
Patent Document 2 also discloses a technique for raising the temperature of wet paper by bringing steam into contact with the wet paper in this way.
[0006]
[Patent Document 1]
JP 55-137293 A
[Patent Document 2]
US Pat. No. 5,149,401
[0007]
[Problems to be solved by the invention]
By the way, while the present inventors have repeatedly conducted extensive research on the dewatering rate of wet paper by steam heating, even if the steam supply amount is increased to further increase the dewatering rate, the dewatering rate may decrease. I found out. This is considered to be caused by an increase in the amount of steam supplied and an increase in the amount of condensed water.
[0008]
However, the above-described conventional paper machine does not pay attention to such a dehydration rate change with respect to the steam supply amount, and it cannot be said that an optimum steam supply amount is necessarily set, and the dewatering is performed efficiently. In terms, there are still challenges.
The present invention has been conceived in view of the above-described problems, and an object of the present invention is to provide a paper machine and a paper making method in which a paper raw material layer can be dehydrated more efficiently in a paper machine.
[0009]
[Means for Solving the Problems]
  For this reason, the paper machine of the present invention according to claim 1 is a paper machine that performs paper making by removing water while holding the paper raw material liquid jetted from the head box in a layered state and running the paper raw material layer.A forming part that forms the paper layer by dehydrating water while the paper raw material liquid ejected from the head box is held in layers and running the paper raw material layerAre provided as heating means for heating the paper raw material layer (wet paper) in order to promote the water removal,It has a steam box that guides the supply of steam to the paper raw material layer and is arranged so that the peripheral edge of the opening at the tip is in contact with or close to the wire.Steam-type heating means for supplying steam to the paper raw material layer and heating the paper raw material layer by the condensing action of the steam; and the steam-type heating means so that the paper raw material layer has a preset target temperature. Adjusting means for adjusting the steam supply state by the steam heating means in correspondence with the raw material concentration state of the paper raw material layer when passing throughA first suction box that is provided on the opposite side of the steam box with the paper raw material layer interposed therebetween, and sucks the steam injected from the steam box; And a device for absorbing and removing moisture from the paper raw material layer.It is characterized by having.
[0010]
Note that the steam here is not limited to saturated steam, and may be, for example, heated steam, moist air, or the like. In addition, the raw material concentration state of the paper raw material layer is detected in real time and the steam supply amount is adjusted based on this detection information, or the raw material concentration state of the paper raw material layer is obtained in advance, and this is obtained in advance. The steam supply amount may be adjusted based on the raw material concentration state.
[0011]
  The paper machine of the present invention described in claim 2 is the configuration described in claim 1,The apparatus that absorbs and removes moisture includes a second suction box.It is characterized by that.
  According to a third aspect of the present invention, there is provided a paper machine according to the first or second aspect, wherein the apparatus for absorbing and removing moisture includes a suction roll.
  According to a fourth aspect of the present invention, in the configuration of the second or third aspect, the suction force of the second suction box is set larger than the suction force of the first suction box. It is characterized by.
[0012]
  Claim5The paper machine according to the present invention described in claimIn any one of 1-4In the described configuration, the forming part is configured as a twin wire former having wires on both sides of the paper raw material layer. The present invention is not necessarily limited to the twin wire, and may be a single-sided long net that holds only one side of the paper raw material layer.
[0013]
ContractClaim6The paper machine according to the present invention described in claim5In the described configuration, sealing means for sealing the inside and outside of the steam box is provided at the periphery of the opening at the tip of the steam box.
[0014]
  Claim7The paper machine according to the present invention described in claim6In the described configuration, the sealing means is a sealing member that is attached to the peripheral edge of the tip opening of the steam box and abuts against the wire.
  Claim8The paper machine according to the present invention described in claim6In the configuration described above, the sealing means is provided upstream of the peripheral edge of the opening of the steam box in the running direction of the paper raw material layer, and the steam box in the wake of the paper raw material layer by jetting gas It is characterized by being a gas injection device that suppresses entry into the interior. In this case, it is preferable that the gas injection device injects the gas toward the upstream side with an injection angle with respect to the wet paper being about 15 to 40 °.
[0015]
ContractThe paper machine of the present invention according to claim 9 is a claim.In any one of 1-8In the described configuration, theFirstThe downstream end portion in the running direction of the paper raw material layer of the suction box is characterized in that it is disposed downstream of the downstream end portion in the running direction of the steam box.
[0017]
  Claim10The paper machine according to the present invention described in claim1-9In the configuration according to any one of the above, the inside of the steam box is divided into a plurality in the width direction of the paper raw material layer, and theFirstThe inside of the suction box is divided into a plurality in the width direction of the paper raw material layer so as to correspond to the division in the steam box.FirstIt is characterized in that the steam injection state and the steam suction state can be adjusted for each divided region in the suction box.
[0018]
  Claim 11The paper machine according to the present invention described in claim 110In the configuration according to any one of the above, the steam supplied by the steam heating means heats the paper raw material layer by acting as a collision jet on the paper raw material layer.
  Claim 12The paper machine according to the present invention described in claim 1 to 1.1The configuration described in any one of the above is characterized in that a control means for automatically adjusting the adjusting means is provided.
[0019]
  Claim 13The paper machine according to the present invention described in claim 12In the configuration described above, a raw material concentration detecting means for detecting a raw material concentration of the paper raw material layer when passing through the steam heating means is provided in the vicinity of the steam heating means. Based on the detection information by the raw material concentration detection means, the steam supply state by the steam heating means is controlled so that the paper raw material layer is heated to the target temperature. Further, the raw material concentration detecting means is, for example, a moisture content sensor, and the raw material concentration can be estimated from the moisture content of the paper raw material layer detected by the moisture content sensor.
[0020]
  Claim 14The paper machine according to the present invention described in claim 1 to 1.3In the configuration according to any one of the above, as the heating means for heating the paper raw material layer on the downstream side in the running direction of the paper raw material layer from the installation location of the steam heating means, And an air jet type heating means for heating the paper raw material layer by the impinging jet of the high-temperature air.
[0021]
  Claim 15The paper machine according to the present invention described in claim 1 to 1.4In the structure according to any one of the above, as the heating means, a first heating means for heating from one side of the paper raw material layer, and a second heating means for heating from the other side of the paper raw material layer; Is provided.
  Claim 16Papermaking of the present invention as describedMethodIs a paper-making method in which the paper raw material liquid ejected from the head box is held in layers and paper is made by removing moisture while the paper raw material layer is runningSoAndIn a forming part in which the paper raw material liquid ejected from the head box is held in layers and water is dehydrated while the paper raw material layer is running to form a paper layer.Steam is supplied to the paper raw material layer at the location to be heated so that the paper raw material layer reaches a preset target temperature, and the paper raw material layer is heated by the condensing action of the steam.And sucking the vapor jetted from the opposite side across the paper raw material layer,furtherThatOn the downstream sideIt is characterized by absorbing and removing moisture from the paper raw material layer. As described above, the steam here is not limited to saturated steam, but may be, for example, heated steam, humid air, or the like.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[1] First embodiment
1 to 3 are diagrams for explaining a paper machine as a first embodiment of the present invention. FIG. 1 is a schematic diagram showing the paper machine, and FIG. 2 is a schematic diagram of a steam box and a suction box. FIG. 3A is a cross-sectional view in the wet paper running direction, FIG. 3B is a cross-sectional view taken along line AA in FIG. 3A, and FIG. It is a graph which shows.
[0023]
In this paper machine, as shown in FIG. 1, a twin wire former is adopted, and when a pulp suspension (paper raw material liquid) 1a is jetted and supplied between the wires 3a and 3b by the head box 2, these wires are used. 3a and 3b are held in layers to form a wet paper (paper raw material layer) 1. This wet paper 1 is dehydrated by bending the forming roll 4 for dehydration by the tension of the wires 3a and 3b, or by curving the conveyance path. Is dehydrated by a blade shoe 5 or the like.
[0024]
Here, on the downstream side of the blade shoe 5, the wet paper 1 is heated by the steam box 6, and is sucked and dehydrated by a suction box 7 installed so as to sandwich the steam box 6 and the wet paper 1. Is done. Here, the steam box 6 and the suction box 7 according to the present embodiment will be described in more detail.
As shown in FIGS. 2 (a) and 2 (b), a steam box (steam heating means) 6 as a heating means comprises a steam box body 6a, a heat retaining body 6b, and a seal member (seal means) 6c. ing.
[0025]
The steam box main body 6a has, for example, a machine length of about 100 to 1000 mm in the running direction, and the internal space is divided into a plurality of steam supply chambers 6e by partition walls 6d in the width direction of the wet paper web 1. Each of the steam supply chambers 6d divided by the partition wall 6d has a steam inlet 6f for taking in the steam from the steam generation source 10, and a tip opening 6g on the surface facing the wire 3a. Yes. In the present embodiment, a seal member 6c is provided at the tip opening 6g of the steam box body 6a, and the seal member 6c is in contact with the wire 3a.
[0026]
Moreover, the temperature of the wires 3a and 3b and the wet paper web 1 can be heated to about 40-100 degreeC by supplying the vapor | steam from the vapor | steam generation source 10 to each vapor | steam supply chamber 6e. The supplied steam can also act on the wet paper 1 as a collision jet, so that the wet paper 1 can be efficiently heated.
The heat retaining body 6b is a heat retaining structure having, for example, a heat insulating material or a heat insulating layer, or a heating device such as an electric heater, a heating steam jacket, and a high temperature air jacket, and is attached to the outer wall of the steam box body 6a. It is designed to keep warm. Thereby, steam condensation and dew condensation on the inner wall surface of the steam box body 6a (that is, the inner wall surface of the steam supply chamber 6e) can be prevented.
[0027]
The seal member 6c is mounted on the periphery of the tip opening 6g of each steam supply chamber 6e so as to contact the wire 3a, and functions to seal the inside and outside of the steam box body 6a and each steam supply chamber 6e. . Thereby, the airtightness of the inside of the steam box main body 6a and each steam supply chamber 6e is ensured. For this sealing member 6c, for example, an elastic material such as rubber is suitable from the viewpoint of sealing properties. However, since heat resistance is also required, a heat resistant material such as bakelite is also suitable. Of course, a material having both elasticity and heat resistance such as heat-resistant rubber is more preferable.
[0028]
Without the seal member 6c, the wake air enters from the gap between the upstream side of the tip opening 6g and the wire 3a, so that the contact of the steam with the wet paper 1 may be hindered. The steam can be reliably brought into contact with the entire wet paper web 1 in each steam supply chamber 6e. That is, it is possible to prevent the efficiency (condensation adhesion efficiency) of vapor condensing and adhering to the wet paper 1 from decreasing.
[0029]
A valve (adjusting means) 11 is provided for each supply pipe connected to each steam supply chamber 6e, and steam supplied to the steam box 6 is supplied from the steam generation source 10 via these valves 11. It has come to be. Further, by controlling the opening / closing operation of each valve 11 by the controller 12, the steam supply amount in the steam supply chamber 6e can be adjusted separately. Note that the steam referred to in the present embodiment may be any of saturated steam, heated steam, and humid air.
[0030]
The suction box 7 has, for example, the same length as the steam box 6 or a shorter length than the steam box 6, and the internal space has the same width as the steam box body 6 a in the width direction of the wet paper web 1 and a plurality of suction chambers by the partition walls. 7e. Each suction chamber 7e divided by the partition wall 7d is formed with a suction port 7f connected to a suction device (not shown) and a tip opening 7g on the surface facing the wire 3b. Furthermore, the suction box 7 is installed so that the tip opening 7g contacts the surface of the wire 3b.
[0031]
In general, the steam box 6 and the wires 3a and 3b are set to have the same width. However, for example, when the width of the steam box 6 is larger than the width of the wires 3a and 3b, steam is exposed from the exposed portion of the tip opening 6g. In order to prevent leakage, it is preferable that a member that prevents (or closes to) the exposed portion to prevent vapor leakage is provided. In the present embodiment, the width of the suction box 7 is formed to be substantially equal to the width of the steam box 6, and this suction box 7 functions as the above member.
[0032]
Then, the wet paper web 1 is heated and heated by such a steam box 6 and a suction box 7 so as to be dehydrated. Specifically, the steam supplied into the steam box 6 is condensed near the surface of the wire 3a and the surface of the wet paper 1 to become high-temperature water. Then, the hot water enters the wet paper 1 by the suction action of the suction box 7, and the entire wet paper 1 is heated by the heat transfer of the high temperature water, and the water inside the wet paper 1 is sucked by the suction box 7. Thus, the wet paper 1 is dehydrated.
[0033]
  Further, the temperature raising process is in progress in such a steam box 6, and the wet paper 1 entering the steam box 6 is gradually heated in the steam box 6, but the entire wet paper 1 is heated. There will be a delay. Therefore, in the paper machine, as shown in FIG. 1, the wet paper 1 in a state where the temperature is raised in the steam box 6 and the dehydration effect is increased, the suction roll 8 and the suction box 9 installed downstream of the steam box 6. To dehydrate further. That is, the suction roll 8 and the suction box 9 absorb and remove moisture from the wet paper 1 by suction (suction).It is like that. Thereby, it can dehydrate more efficiently and can improve a dehydration rate.
[0034]
By the way, as described above, the present inventors have found that the dehydration rate may decrease even if the steam supply amount is increased in order to further increase the dehydration rate. This is thought to be because the amount of heat supplied increases as the amount of steam supplied increases, while the amount of water that condenses into water increases, leading to an increase in moisture content. How to set is important.
[0035]
Therefore, it was examined how the dehydration rate changes according to the paper raw material concentration of the wet paper 1 under a certain suction condition. The result is shown in FIG.
FIG. 3 shows dehydration improvement characteristics due to the temperature rise effect when the steam supply amount is large and small, and dehydration reduction characteristics due to the dehydration resistance when the suction pressure is constant.
[0036]
For example, as shown by the lines M1 and M2 in FIG. 3, the characteristics of the dehydration promoting effect due to the steam supply are less in moisture content as the raw material concentration is higher, regardless of whether the steam supply amount is large or small. Since the mass is low, the heat capacity is reduced, the temperature rise of the wet paper 1 is increased, and the dehydration rate is increased (that is, the dehydration rate is improved by the temperature rising effect of the wet paper 1). As can be seen by comparing the lines M1 and M2, the dehydration rate is naturally higher when the steam supply amount is large (M1) than when it is small (M2).
[0037]
On the other hand, when the suction pressure is constant, as shown by the line S in FIG. 3, the characteristic of the dehydration promoting effect by suction increases the dehydration resistance and the dehydration rate as the raw material concentration increases.
Therefore, when the steam supply is large, the sum of the dehydration promoting effect by the steam supply shown by the line M1 and the dehydration promoting effect by the suction shown by the line S is a characteristic of the substantial dehydration promoting effect, As shown by the line L1 in FIG. 3, this dehydration promoting effect has a mountainous characteristic that it gradually decreases after increasing to a certain raw material concentration.
[0038]
Similarly, when the steam supply amount is small, the characteristics of the substantial dehydration promotion effect are the sum of the dehydration promotion effect by the steam supply shown by the line M2 and the dehydration promotion effect by the suction shown by the line S. That is, the line L2.
In general, the dewatering speed v corresponding to the dewatering improvement rate is expressed by equation (1) according to Darcy's law.
[0039]
[Expression 1]

[0040]
In this equation (1), the vertical pressure difference ΔP, the wet paper web dewatering resistance coefficient R_mat, Wire dehydration resistance coefficient R_wIs constant, and paying attention to the relationship between the dehydration rate v and the water viscosity μ, the dehydration rate v is inversely proportional to the water viscosity μ. Further, there is a relationship between the water viscosity μ and the wet paper temperature that the water viscosity μ decreases as the wet paper temperature increases. That is, there is a relationship that the dewatering speed v increases as the wet paper temperature increases.
[0041]
Usually, according to the Darcy law, the wet paper 1 is heated by the heated steam, so the dehydration rate increases and the dehydration rate increases. At the same time, the dehydration resistance increases as the raw material concentration increases. As shown in FIG. 3, there is a mountain characteristic, and the most efficient raw material concentration corresponding to the steam supply state exists.
[0042]
Therefore, in order to improve the dehydration rate, it is preferable to set an optimum steam supply amount according to the raw material concentration of the wet paper 1 in consideration of such characteristics. For this reason, as shown in FIG. 1, the paper machine has a position corresponding to the position of each steam supply chamber 6e in the vicinity of the upstream side of the steam box 6 and in the width direction of the wet paper web 1 (that is, the wet paper web 1). A moisture content sensor (raw material concentration detecting means) 13 for detecting the moisture content of the wet paper web 1 (corresponding to the raw material concentration, raw material concentration (%) = 100−water content (%)) is provided in the heating target portion). (Only one is shown in FIG. 1).
[0043]
Then, the controller 12 sets each moisture so that the temperature of the wet paper 1 passing through each steam supply chamber 6e becomes a target wet paper temperature (a preset target temperature corresponding to the raw material concentration of the wet paper 1). Based on the detection information from the rate sensor 13, the opening / closing operation of each valve 11 is adjusted, and the steam supply state of each steam supply chamber 6e is controlled in real time. For example, assuming that the steam supply chamber 6e is arranged at a certain point and the reference raw material concentration of the wet paper 1 entering this point is 12%, the raw material concentration of the wet paper 1 is 10% by the moisture percentage sensor 13. Is detected, the controller 12 controls the valve 11 so as to increase the steam supply amount. If the moisture content sensor 13 detects that the raw material concentration of the wet paper 1 is 14%, the controller 12 determines the steam supply amount. The valve 11 is controlled so as to reduce.
[0044]
In addition, since the steam injection state and the steam suction state can be adjusted for each divided region in the steam box 6 and the suction box 7, dewatering adjustment in the width direction of the wet paper web 1 can be easily performed.
[0045]
Further, since steam is supplied to the wet paper 1 via the wire 3a, the wet paper 1 is not destroyed by contact between the peripheral edge of the tip opening 6g of the steam box 6 and the wet paper 1, and the high temperature. It is possible to prevent pulp deterioration and discoloration caused by direct contact of the steam with the wet paper web 1. In other words, in the case of a configuration in which steam is directly blown onto the wet paper 1 as in the prior art, it is necessary to provide a gap between the steam box 6 and the wet paper 1 so that the wet paper 1 is not damaged, and steam discharge is great. However, since this paper machine uses twin wires that support both sides of the wet paper 1 with the wires 3a and 3b, the wet paper 1 is not damaged by bringing the steam box 6 into contact with the wire. The above gap can be eliminated, and the amount of vapor released can be suppressed as compared with the conventional case. That is, steam loss can be prevented and the supplied steam can be used efficiently.
[0046]
Moreover, since the sealing property in the steam box 6 is ensured by the sealing member 6c of the steam box 6, it is possible to further suppress the release of steam from the inside of the steam box 6 to the outside.
[0047]
Further, conventionally, attention has been paid to the point that the wet paper 1 is heated and dehydrated by allowing the vapor to penetrate into the wet paper 1, so that the vapor easily penetrates, that is, the wet paper 1 at the last part of the former. The steam box 60 and the suction box 70 (see FIGS. 8 (a) and 8 (b)) are installed in a position “before completion of dehydration” and where the wet paper web 1 is in a porous state or in a state where voids are formed. There was a need. On the other hand, in the present paper machine, the wet paper 1 is heated and dehydrated by substituting the hot water condensed near the surface of the wet paper 1 with the water inside the wet paper 1 by the suction action of the suction box 7. Therefore, it is not always necessary to allow the vapor to penetrate into the wet paper web 1 as in the prior art.
[0048]
That is, in the past, the steam box had to be installed at a position before the completion of dehydration (that is, near the former outlet), but according to the present invention, it can be installed more upstream. Thereby, dehydration of the wet paper web 1 in the former can be promoted from the upstream side. Moreover, in the present paper machine, the optimum steam supply is performed according to the raw material concentration state of the wet paper 1 as described above, so that the heat dehydration efficiency can be increased. Therefore, dehydration in the former can be performed very efficiently, and the former can be made compact, and the space for installing the former can be reduced.
[0049]
Moreover, the heat transfer efficiency by the steam condensation of this paper machine is about 25 times the heat transfer efficiency by the conventional steam permeation, which is very high compared to the conventional one. Therefore, since the temperature of the wet paper web 1 has been insufficient in the past, even if the suction box 9 is installed on the downstream side of the suction box 70, a high dehydration effect cannot be obtained. Since it is warm, a high dehydration effect is obtained by the suction roll 8 and the suction box 14 on the downstream side of the suction box 7, and the dehydration of the wet paper 1 can be promoted.
[0050]
In the present embodiment, the internal space of the steam box 6 and the suction box 7 is divided to adjust the steam injection state and the steam suction state for each divided region. When the density difference can be ignored, the internal space may not be divided (that is, the partition walls 6d and 7d are not provided). Further, in this case, a steam supply state necessary for obtaining a representative raw material concentration (for example, a central portion in the width direction of the wet paper) from each moisture percentage sensor 13 and raising the temperature to the target wet paper web temperature based on the representative raw material concentration. May be set. Alternatively, the moisture content sensor 13 is installed only at one location in the width direction of the wet paper web 1 (for example, the central portion in the width direction of the wet paper web 1), and the temperature reaches the target wet paper web temperature based on the raw material concentration obtained from the moisture content sensor 13. A steam supply state necessary for heating may be set.
[0051]
Further, in the present embodiment, the controller 12 automatically adjusts the opening / closing operation of the valve 11 based on the detection information from the moisture content sensor 13, but the valve opening / closing operation is performed based on the detection information from the moisture content sensor 13. May be performed manually by the operator.
In the present embodiment, the steam box 6 and the suction box 7 are provided with a former that forms a paper layer. However, a press part on the downstream side of the former (the paper raw material layer formed with the former is pressurized). Of course, it is also possible to prepare a part for further dehydration of water.
[0052]
[2] Second embodiment
Next, a paper machine as a second embodiment of the present invention will be described.
As shown in FIG. 4, in addition to the configuration of the first embodiment, the present paper machine is configured to further include another suction box 7A at a position close to the downstream side of the suction box 7.
[0053]
As described in the first embodiment, the temperature raising process is in progress in the steam box 6, and the wet paper 1 that has entered the steam box 6 is gradually heated in the steam box 6. There is a delay before the temperature rises. Therefore, in the paper machine, the wet paper 1 in a state where the temperature is raised in the steam box 6 and the dehydration effect is enhanced is further dehydrated by the suction box 7A. Further, since the suction box 7A sucks the wet paper 1 in a state where the dewatering effect is enhanced, it is possible to perform further dewatering even if it is equal to the suction force of the suction box 7, but the suction force of the suction box 7A. Is preferably set larger than the suction force of the suction box 7. Thereby, it can dehydrate more efficiently and can improve a dehydration rate.
[0054]
[3] Third embodiment
Next, a paper machine as a third embodiment of the present invention will be described.
As shown in FIG. 5, the paper machine is configured such that, in the configuration of the first embodiment, the downstream end of the suction box 7 is located downstream of the downstream end of the steam box 6. Has been.
[0055]
As described above, since there is a delay until the entire wet paper web 1 is heated in the steam box 6, the wet paper web 1 can be dehydrated more efficiently by shifting the suction box 7 to the downstream side. And the dehydration rate can be further improved.
In the present embodiment, the suction box 7 according to the first embodiment is arranged so as to be shifted by a predetermined distance to the downstream side, but the upstream end of the suction box 7 according to the first embodiment remains in the same position. The downstream end of the suction box 7 may be positioned on the downstream side of the downstream end of the steam box 6.
[0056]
[4] Fourth embodiment
Next, a paper machine as a fourth embodiment of the present invention will be described.
As shown in FIG. 6, the paper machine includes a gas injection device (seal means) 14 for injecting gas toward the upstream side in the vicinity of the upstream end of the steam box 6 in the configuration of the first embodiment. Configured. Moreover, it is preferable that this gas injection apparatus 14 injects gas toward the upstream side by making the injection angle θ with respect to the wet paper about 15 to 40 °.
[0057]
Thereby, the approach of the wake air into the steam box 6 can be more reliably suppressed. In addition, when the wake air can be sufficiently suppressed by the gas injection device 14, the seal member 6c on the upstream side of the steam box 6 may be omitted.
[0058]
[5] Fifth embodiment
Next, a paper machine as a fifth embodiment of the present invention will be described.
As shown in FIG. 7, the paper machine is configured to include two sets of a steam box 6 and a suction box 7 according to the first embodiment. Specifically, a unit of a steam box 6 (first heating means) 6 and a suction box 7, a steam box (second heating means) 6 ′ and a suction box 7 ′ are provided. Steam is supplied to one side of the wet paper 1 and steam is also supplied to the other side of the wet paper 1 by the steam box 6 ′. Thereby, both surfaces of the wet paper web 1 can be dehydrated uniformly, and it becomes possible to manufacture a product with uniform both sides with little difference between the front and back sides.
[0059]
[6] Other
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.
[0060]
Generally, the installation position of the steam box 6 is determined in advance by design, but since the raw material concentration (reference raw material concentration) of the wet paper 1 at this installation position can also be predicted at the design stage, the paper machine has this reference raw material concentration. It is only necessary to supply steam so as to achieve the target wet paper web temperature corresponding to. In this embodiment, when the moisture content sensor 13 detects the actual raw material concentration state of the wet paper 1 and the raw material concentration of the wet paper 1 that passes through the steam box 6 deviates from the above-mentioned reference raw material concentration, this deviation occurs. In order to correct the above, the steam supply amount of the steam box 6 is adjusted by feedback control. However, when such a deviation in the raw material concentration can be almost ignored, the moisture content sensor 13 is not provided and an open loop is used. You may comprise so that a fixed vapor | steam may always be supplied.
[0061]
Also, a means for detecting the temperature of the wet paper 1 may be provided, and the steam supply may be adjusted so that the wet paper 1 reaches the target wet paper temperature by feedback control based on this detection information. Even in this case, the wet paper web 1 can be efficiently heated and dehydrated, and the dehydration rate can be improved.
[0062]
Moreover, you may provide the air jet type heating means which sprays high temperature air on the wet paper 1 and heats the wet paper 1 by the collision jet of high temperature air in the downstream of the steam box 6. FIG. With this configuration, the wet paper 1 that has been heated in the steam box 6 can be further heated, and the dewatering efficiency of the suction roll 8 and the suction box 9 can be improved.
[0063]
Further, the steam box 6 is preferably installed in a former having a high moisture content of the wet paper 1 because it is highly effective when used in a state where the wet paper 1 has a high moisture content. May be. In addition, since the air jet heating means is highly effective when used in a state where the moisture content of the wet paper web 1 is lower than that of the wet paper web 1 in the former, it is preferably installed in the press part where the water content of the wet paper web 1 is lower than that of the former. You may install in a downstream part (near exit).
[0064]
Further, in the above embodiment, the sealing member is configured to abut on the wire 3a in order to ensure the sealing property in the steam box 6. However, if the sealing property in the steam box 6 can be secured, the sealing member 6c is connected to the wire. You may comprise so that it may adjoin to 3a. In addition, the seal member 6c may not be provided as long as the end opening 6g of the steam box 6 is in contact with or close to the wire 3a to ensure the airtightness in the steam box 6.
[0065]
The present invention is not necessarily limited to the twin wire, and may be a single-sided long net that holds only one side of the paper raw material layer.
[0066]
【The invention's effect】
  As detailed above, claims 1 to5According to the paper machine of the present invention described above, in the part for removing moisture, the adjusting means causes the paper raw material layer to pass through the steam heating means so that the paper raw material layer has a preset target temperature. Since the steam supply state by the steam heating means is adjusted in accordance with the raw material concentration state, the paper raw material layer can be heated and dehydrated more efficiently. Thereby, a dehydration rate can be improved.
  Further, the steam heating means is provided with a steam box for guiding the supply of steam to the paper raw material layer, and the steam box is arranged so that the peripheral edge of the opening at the tip is in contact with or close to the wire. Therefore, steam can be efficiently supplied to the paper raw material layer.
Further, the first suction box sucks the steam injected from the steam box on the opposite side of the steam box across the paper material layer, so that the high temperature water condensed on the surface of the paper material layer penetrates into the inside of the paper material layer. be able to.
In addition, in addition to the first suction box, a device for absorbing and removing moisture from the paper raw material layer is provided downstream of the steam box in the running direction, so that the temperature of the entire paper raw material layer is raised. Can be dehydrated.
  In particular, according to the paper machine of the present invention described in claim 4, the suction force of the second suction box in the running direction of the paper raw material layer is set to be larger than the suction force of the first suction box on the upstream side. Therefore, it is possible to further dehydrate the water content of the paper raw material layer heated in the upstream steam box, and to further improve the dehydration rate.
[0067]
ContractClaim6According to the described paper machine of the present invention, since the sealing means for sealing the inside and outside of the steam box is provided at the periphery of the opening at the tip of the steam box, steam can be supplied to the paper raw material layer more efficiently. Can do.
[0068]
  Claim7According to the paper machine of the present invention described above, the sealing means is a sealing member that is attached to the peripheral edge of the opening of the end of the steam box and abuts against the wire. The paper raw material layer can be efficiently supplied.
  Claim8According to the paper machine of the present invention described above, the sealing means is provided on the upstream side in the running direction of the paper raw material layer from the peripheral edge of the opening of the steam box, and the wake vapor of the paper raw material layer is injected by injecting gas. Since the gas injection device suppresses entry into the box, entry of wake air into the steam box can be more reliably suppressed, and steam can be efficiently supplied to the paper raw material layer.
[0069]
ContractAccording to the paper machine of the present invention described in claim 9,FirstSince the downstream end portion in the running direction of the paper raw material layer of the suction box is disposed downstream of the downstream end portion in the running direction of the steam box, the moisture in the heated paper raw material layer can be further dehydrated. And the dehydration rate can be further improved.
[0071]
  Claim10According to the paper machine of the present invention described, the inside of the steam box is divided into a plurality in the width direction of the paper raw material layer,FirstThe inside of the suction box is divided into a plurality of width directions of the paper raw material layer so as to correspond to the division in the steam box.FirstSince the steam injection state and the steam suction state can be adjusted for each divided region unit in the suction box, the dehydration rate can be adjusted for each divided region unit.
[0072]
  Claim11According to the described paper machine of the present invention, the steam supplied by the steam heating means heats the paper raw material layer by acting as a collision jet on the paper raw material layer, so that the temperature of the paper raw material layer is increased more efficiently. Can be dehydrated.
  Claim 12According to the paper machine of the present invention described above, since the control means for automatically adjusting the adjusting means is provided, the steam supply state can be automatically adjusted.
[0073]
  Claim 13According to the described paper machine of the present invention, the control means controls the steam supply state by the steam heating means based on the detection information by the raw material concentration detection means so that the paper raw material layer is heated to the target temperature. Therefore, it can be adjusted to a steam supply state in which optimum dewatering efficiency can be obtained.
  Claim 14According to the paper machine of the present invention, the high temperature air is blown to the paper raw material layer as a heating means for heating the paper raw material layer on the downstream side in the running direction of the paper raw material layer from the installation location of the steam heating means. Air jet type heating means for heating the paper raw material layer by the impinging jet of air is provided, so the paper raw material layer that has been heated in the steam type heating means can be further heated to dehydrate it. The rate can be further improved.
[0074]
  Claim 15According to the paper machine of the present invention, the first heating means for heating from one side of the paper raw material layer and the second heating means for heating from the other side of the paper raw material layer are provided as the heating means. Therefore, both surfaces of the paper raw material layer can be dehydrated uniformly.
  Claim 16According to the papermaking method of the present invention described, steam is supplied to the paper raw material layer at the location to be heated so that the paper raw material layer reaches a preset target temperature, and the paper raw material layer is heated by the condensation action of the steam. Thereafter, moisture is absorbed and removed from the paper raw material layer, so that the temperature of the paper raw material layer can be increased and dehydrated more efficiently. Thereby, a dehydration rate can be improved.
[Brief description of the drawings]
FIG. 1 is a configuration diagram schematically showing a paper machine as a first embodiment of the present invention.
FIGS. 2A and 2B schematically show a steam box and a suction box according to a first embodiment of the present invention, in which FIG. 2A is a cross-sectional view in the wet paper running direction, and FIG. FIG.
FIG. 3 is a graph showing a change in dewatering rate (dehydration promoting effect) with respect to the raw paper concentration of the wet paper as the first embodiment of the present invention.
FIG. 4 is a configuration diagram schematically showing a paper machine as a second embodiment of the present invention.
FIG. 5 is a configuration diagram schematically showing a paper machine as a third embodiment of the present invention.
FIG. 6 is a configuration diagram schematically showing a paper machine as a fourth embodiment of the present invention.
FIG. 7 is a configuration diagram schematically showing a paper machine as a fifth embodiment of the present invention.
FIGS. 8A and 8B schematically show a steam box and a suction box according to a conventional paper machine, where FIG. 8A is a cross-sectional view in the wet paper running direction, and FIG. 8B is a cross-sectional view along AA in FIG. .
[Explanation of symbols]
1 Wet paper (paper raw material layer)
1a Pulp suspension (paper raw material liquid)
2 Headbox
3a, 3b wire
4 Forming roll
5 Blade shoe
6, 6 ', 60 Steam box (steam heating means)
6a Steam box body
6b Insulation body
6c Seal member (sealing means)
6d partition wall
6e Steam supply room
6f Steam inlet
6g Tip opening
7,7A, 7 ', 70 Suction box
7d partition wall
7e Suction chamber
7f Suction port
7g Tip opening
8 Suction roll
9 Suction box
10 Steam source
11 Valve (Adjustment means)
12 Controller (control means)
13 Moisture content sensor (raw material concentration detection means)
14 Gas injection device (sealing means)

Claims (16)

In the paper machine that holds the paper raw material liquid jetted from the head box in layers and removes moisture while running this paper raw material layer,
In order to promote the removal of moisture in the forming part that forms the paper layer by dehydrating the paper raw material liquid ejected from the head box while holding the paper raw material layer in a running state. Provided with a steam box that guides the supply of steam to the paper raw material layer and is arranged so that the peripheral edge of the opening at the tip is in contact with or close to the wire. Steam-type heating means for supplying steam to the paper raw material layer and heating the paper raw material layer by the condensing action of the steam;
The steam supply state by the steam heating means is adjusted in accordance with the raw material concentration state of the paper raw material layer when passing through the steam heating means so that the paper raw material layer has a preset target temperature. Adjusting means ;
A first suction box provided on the opposite side of the steam box across the paper raw material layer and sucking the steam injected from the steam box;
A paper machine comprising: a device provided on the downstream side of the downstream end portion in the running direction of the steam box, and a device for absorbing and removing moisture from the paper raw material layer . The apparatus for absorbing and removing moisture includes a second suction box.
The paper machine according to claim 1, wherein: The apparatus for absorbing and removing the moisture includes a suction roll.
The paper machine according to claim 1 or 2, characterized by the above. 4. The paper machine according to claim 2 , wherein the suction force of the second suction box is set larger than the suction force of the first suction box. The paper machine according to any one of claims 1 to 4, wherein the forming part is configured as a twin wire former having wires on both sides of the paper raw material layer. The paper machine according to any one of claims 1 to 5 , wherein sealing means for sealing the inside and outside of the steam box is provided at the periphery of the opening at the tip of the steam box. 7. The paper machine according to claim 6 , wherein the sealing means is a sealing member that is attached to a peripheral edge of a front end opening of the steam box and abuts against the wire. The sealing means is provided upstream of the peripheral edge of the opening of the steam box in the running direction of the paper raw material layer, and the wake of the paper raw material layer enters the steam box by injecting gas. The paper machine according to claim 6 , wherein the paper machine is a gas injection device to be suppressed. The running direction downstream side end portion of the paper raw material layer of the first suction box is characterized in that it is arranged downstream of the running direction downstream side end portion of the steam box, according to claim 1 9. The paper machine according to any one of items 8 . With the evaporated in air box is divided into a plurality in the width direction of the paper raw material layer, the inside first suction box, into a plurality of the width direction of the paper raw material layer so as to correspond to the split in the vapor box Divided,
Wherein the the evaporated adjustment of the suction state of the injection state and steam of the steam in the divided region unit in the gas box and the first suction box is enabled, one of the preceding claims 1 The paper machine described in the paragraph. Vapor supplied by the steam heating means, characterized by heating the said paper raw material layer by acting as a collision jet into the paper material layer, according to any one of claims 1-10 Paper machine. The paper machine according to any one of claims 1 to 11 , further comprising control means for automatically adjusting the adjusting means. A raw material concentration detecting means for detecting the raw material concentration of the paper raw material layer when passing through the steam heating means is provided in the vicinity of the steam heating means,
The control means controls a steam supply state by the steam heating means so that the paper raw material layer is heated to the target temperature based on detection information by the raw material concentration detection means. claim 1 2 paper machine according. As a heating means for heating the paper raw material layer on the downstream side in the running direction of the paper raw material layer from the place where the steam heating means is installed, high-temperature air is blown to the paper raw material layer and the high-temperature air impinges on the paper raw material layer. wherein the air jet type heating means for heating the paper stock layer is provided, the paper machine according to any one of claims 1 to 1 3. As the heating means, a first heating means for heating from one side of the paper raw material layer and a second heating means for heating from the other side of the paper raw material layer are provided. , paper machine according to any one of claims 1 to 1 4. A paper making method for making paper by removing moisture while running the paper raw material layer while holding the paper raw material liquid jetted from the head box in a layer form,
The paper raw material layer reaches a preset target temperature in a forming part in which the paper raw material liquid ejected from the head box is held in layers and water is dehydrated while the paper raw material layer is running to form the paper layer. As described above, the steam is supplied to the paper raw material layer at the heating target location, the paper raw material layer is heated by the condensing action of the steam, and the steam jetted from the opposite side across the paper raw material layer is sucked. A papermaking method, further comprising absorbing and removing moisture from the paper raw material layer on the downstream side .

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