JP3767822B2

JP3767822B2 - Resin coating repair method and dehydration processing apparatus

Info

Publication number: JP3767822B2
Application number: JP2003069533A
Authority: JP
Inventors: 忍佐伯; 良治小林; 正記栗林; 盛男岩本; 良一黒木
Original assignee: Dai Ichi High Frequency Co Ltd
Current assignee: Dai Ichi High Frequency Co Ltd
Priority date: 2003-03-14
Filing date: 2003-03-14
Publication date: 2006-04-19
Anticipated expiration: 2023-03-14
Also published as: JP2004276360A

Description

【０００１】
【発明の属する技術分野】
この発明は、樹脂被覆の補修方法および脱水処理装置に関し、詳しくは、樹脂被覆した鋼管等が使用されて被覆が損傷したときその損傷部に樹脂被覆を再形成するための技術に関する。
【０００２】
【従来の技術】
金属露出部に防食被覆（ライニング）を施すに際して、被覆用の樹脂材料原料として粉体樹脂を選定し、金属露出部を裏側から加熱し、吹付装置を用いて金属露出面およびその周辺に粉体樹脂を吹き付ける防食被覆施工方法が知られている（例えば特許文献１，４参照）。
また、金属条材等に樹脂被覆するに際して、被覆用粉体樹脂を多孔質シート状に成形し、これを被覆対象物に当てがい、加熱溶融させて樹脂被覆層を形成する手法が知られている（例えば特許文献２参照）。
更にまた、金属管類の内面に樹脂被覆層を形成するに際して、被覆対象部位から空気を吸引除去して又はしながら、被覆対象部位に粉体樹脂を充填し、加熱融着させる手法が知られている（例えば特許文献３参照）。
【０００３】
これらは、平坦な鋼板や真っ直ぐな鋼管などに適用可能なことはもちろん、新規の施工時に被覆されず局所的に残っていた樹脂被覆対象部分（例えば溶接個所）や，継手部，分岐部，湾曲部などにも適用可能であり、さらに、被覆損傷部の補修にも適用されている。
更には、樹脂被覆された金属部材を対象にその被覆損傷部を補修する場合、傷んだ被覆を除去し、更にそれで出来た被覆欠落部とその周りの正常被覆とを補修対象領域として、その表面に清浄処理を施し、それから、上述の手法を用いて、被覆欠落部を覆う樹脂被覆を再形成している。
【０００４】
【特許文献１】
特開平０１−３１０７６３号公報（第１頁、第１図）
【特許文献２】
特開昭６２−２４２５１９号公報（第１頁、第１図〜第１０図）
【特許文献３】
特開昭６０−２２２１７７号公報（第１頁、第１図）
【特許文献４】
特開昭６０−１１０３６８号公報（第１頁、第２図）
【０００５】
【発明が解決しようとする課題】
ところが、新規の被覆形成と異なり、使用後の補修では、補修部の再形成被覆やその近傍の既存被覆に不具合が発生することがあった。具体的には、被覆に凹凸が発現したり、一部の被覆が母材から剥離してしまう等々である。従来は、このような不具合は、被覆内部の傷みに気づかないで損傷被覆を正常被覆として除去せずに残したことに起因して発生するものと解釈して、再形成した被覆を除去するとともに、その周りの既存被覆も除去して、被覆欠落部を広げてから、あらためて被覆の再形成をやり直していた。
【０００６】
しかしながら、長年に亘る補修業務の遂行とそれに伴う調査や分析の結果、上記のような不具合の発生原因としては、内部損傷の見落としよりも、被覆の含水の影響の方が大きい、ということが判明した。長期に及ぶ通水使用や水中での使用などによって吸水がなされて、被覆の含水量が０．１mass％近くに増えていると、被覆融着のための加熱時（２５０℃前後に加熱されることが多い）に、被覆に含まれていた水分が突沸して、被覆の下や被覆層内あるいは被覆層間に膨れが生じて、被覆の凹凸や一部剥離の状態が発生する確率が高くなるのである。
この発明は、このような知見に基づいて創案されたものであり、的確な樹脂被覆の補修方法を実現することを目的とする。
また、本発明は、そのような補修方法の実行に好適な道具を実現することも目的とする。
【０００７】
【課題を解決するための手段】
このような課題を解決するために案出された本発明の請求項１記載の樹脂被覆の補修方法は、樹脂被覆を有する部材に生じている被覆欠落部を補修すべく、この被覆欠落部が含まれるように設定した補修対象領域に樹脂被覆を再形成するに当り、樹脂材料を層状に展着させる被覆層形成操作に先だって、前記補修対象領域の既存樹脂被覆に、これを加熱して被覆中の水分を追い出す脱水処理を施しておく、というものである。
【０００８】
このような樹脂被覆の補修方法にあっては、脱水処理が被覆層形成操作に先行して行われ、この脱水処理で被覆欠落部とその周りが加熱される。そして、被覆欠落部の周りに残っている既存の被覆について、被覆表面ばかりか被覆の内部や被覆下の境界面・接合面からも、脱水がなされる。
これにより、被覆層形成操作で融着のため加熱を行っても含水の突沸は起きないので、不所望な被覆の凹凸等が発生しなくなる。また、被覆層形成操作で加熱を伴わない塗装等を行って補修する場合でも、接着性が改善される。そのため、適切な補修がやり直し不要で確実に行えることとなる。
したがって、この発明によれば、的確な樹脂被覆の補修方法を実現することができる。
【０００９】
また、本発明の請求項２記載の樹脂被覆の補修方法は、上記の樹脂被覆の補修方法であって、赤外線を被覆面に照射して被覆に直接入熱する手法と、被覆の下地を構成する母材に直接入熱し、この熱を母材上の被覆に伝熱させる手法とを編成して、前記補修対象領域に樹脂被覆を再形成するための加熱を行う、ことを特徴とする。
また、本発明の請求項３記載の樹脂被覆の補修方法は、上記の樹脂被覆の補修方法であって、前記脱水処理では前記赤外線を被覆面に照射して加熱し、前記被覆層形成操作では母材に直接入熱して加熱する、ことを特徴とする。
【００１０】
また、本発明の請求項４記載の樹脂被覆の補修方法は、上記の樹脂被覆の補修方法であって、前記脱水処理と前記被覆層形成操作との双方に亘り、被覆の下地を構成する母材に直接入熱して、この熱が母材上の被覆に伝熱されることによって、前記補修対象領域に樹脂被覆を再形成するための加熱が行われる、ことを特徴とする。
また、本発明の請求項５記載の樹脂被覆の補修方法は、上記の樹脂被覆の補修方法であって、母材に対する直接入熱を誘導加熱等の大入熱加熱手段にて行う、ことを特徴とする。
また、本発明の請求項６記載の樹脂被覆の補修方法は、上記の樹脂被覆の補修方法であって、母材より赤外線吸収率の高い塗料を母材に塗り、そこに赤外線（赤外線の含まれる可視光線も含む）を照射することで、母材に対する直接入熱を行う、ことを特徴とする。
【００１１】
また、本発明の請求項７記載の樹脂被覆の補修方法は、上記の樹脂被覆の補修方法であって、前記脱水処理で加熱部位を囲って減圧することを特徴とする。
また、本発明の請求項８記載の樹脂被覆の補修方法は、上記の樹脂被覆の補修方法であって、前記脱水処理で加熱部位を囲って通気することを特徴とする。
また、本発明の請求項９記載の樹脂被覆の補修方法は、上記の樹脂被覆の補修方法であって、前記脱水処理で加熱部位に開放状態で通気することを特徴とする。
また、本発明の請求項１０記載の樹脂被覆の補修方法は、上記の樹脂被覆の補修方法であって、通気する際に温風又は熱風を通気することを特徴とする。
これらのうち何れか一つを行う又は複数を併用することにより、補修部位の脱水が能率良く行える。
【００１２】
このような補修方法の実行に好適な道具として案出された本発明の請求項１１記載の樹脂被覆の脱水処理装置は、赤外線（赤外線の含まれる可視光線も含む）を発する加熱源が格納されており且つ樹脂被覆を有する部材の下地を構成している母材の被覆欠落部およびその周りに前記赤外線を照射するための開口が形成されている（箱状や殻状の）囲体と、前記囲体への給気を行う給気手段と、前記囲体からの排気を行う排気手段とを備えたものである。
【００１３】
このような樹脂被覆の脱水処理装置にあっては、樹脂被覆を有する部材の被覆面に囲体を当てて脱水に使用されるが、その際、開口が被覆欠落部とその周りを囲んだ状態で、作動させられる。そうすると、加熱源から発した赤外線が系外に散逸することなく脱水対象部位に集中して照射される。これにより、被覆欠落部の周りの被覆が加熱されて、そこから水分が蒸発する（加熱により、被覆表面からの水分の蒸発と、被覆中水分の被覆表面への拡散補給が促進される）。この水蒸気は、次々に囲体内へ飛び立って来るが、給気手段と排気手段とによる囲体内への通気によって直ぐに運び出される。これにより、被覆層形成操作に先行する脱水処理が能率良く行われる。したがって、この発明によれば、的確な樹脂被覆の補修方法の実行に好適な脱水処理装置を実現することができる。
【００１４】
また、本発明の請求項１２記載の樹脂被覆の脱水処理装置は、上記の脱水処理装置であって、前記給気手段に給気加熱手段が付加されたものである。
このような樹脂被覆の脱水処理装置にあっては、囲体への通気に際して温風・熱風が送り込まれるので、脱水能率が一層良くなる。
【００１５】
さらに、本発明の請求項１３記載の樹脂被覆の脱水処理装置は、樹脂被覆を有する部材の被覆欠落部およびその周りを囲うための開口が形成されている囲体と、前記囲体への給気を行う給気手段と、この給気手段に付設された給気加熱手段と、前記囲体からの排気を行う排気手段とを備えたものである。
このような樹脂被覆の脱水処理装置にあっては、囲体への通気が行われ、その際に温風・熱風が送り込まれるので、その温風・熱風によって脱水対象部位が加熱されて、そこから水分が蒸発し、その蒸気が送風で運びさられるので、例え囲体内に加熱源が内蔵されていなくても、被覆層形成操作に先行する脱水処理が能率良く行われる。したがって、この発明によれば、的確な樹脂被覆の補修方法の実行に好適な脱水処理装置を実現することができる。
【００１６】
また、本発明の請求項１４記載の樹脂被覆の脱水処理装置は、上記の脱水処理装置であって、前記被覆欠落部の周りの被覆を対象にして表面温度を測定する被覆表面温度検出手段と、前記樹脂被覆の下地を構成している母材の裏面（すなわち前記被覆欠落部の存する面を表としたときの裏面）を対象にして温度測定を行う母材裏面温度検出手段と、それらの検出結果に基づいて前記被覆欠落部の周りの被覆と前記母材との境界面（すなわち被覆下の接合面）の推定温度を算出する界面温度演算手段と、（少なくとも初期段階では）前記推定温度を水の沸点以下に抑えるように前記加熱源および前記給気加熱手段のうち何れか一方または双方の動作制御を行う界面温度制御手段とを備えたものである。
このような樹脂被覆の脱水処理装置にあっては、被覆下での突沸を招きかねない過熱が確実に回避されるので、被覆層形成操作に先行する脱水処理が能率良く且つ的確に行われる。
【００１７】
また、本発明の請求項１５記載の樹脂被覆の脱水処理装置は、上記の脱水処理装置であって、前記被覆欠落部の周りの被覆を対象にして含水率対応物理量を測定する含水率検出手段と、その検出結果に基づいて脱水状態が被覆層形成操作に適う程であるか否かを判別する脱水状態判別手段と、その判別結果に基づいて脱水処理を停止する又はそのための導入処置（例えば停止予約や停止催促）を行う脱水処理停止手段とを備えたものである。
このような樹脂被覆の脱水処理装置にあっては、脱水が十分であれば、それ以上の無駄な脱水処理は省かれるので、被覆層形成操作に先行する脱水処理が極めて能率良く行われる。
【００１８】
また、本発明の請求項１６記載の樹脂被覆の脱水処理装置は、上記の脱水処理装置であって、前記囲体に着脱可能な筒体からなり一端は鞍の縁の形状に形成され他端は前記囲体への装着時に前記開口のところに連結されるアダプタを備えたものである。
このような樹脂被覆の脱水処理装置にあっては、簡素で安価なアダプタを付け替えることで、容易に、径の異なる被覆管に共用される。これにより、被覆層形成操作に先行する脱水処理が能率良く且つ簡便に行える。
【００１９】
【発明の実施の形態】
図１は、本発明の樹脂被覆の補修方法を手順に従って例示しており、（ａ）〜（ｅ）何れも補修部位の縦断端面図である。
ここでは（図１（ａ）参照）、以前に母材１の表面（図では上側の面）に樹脂被覆されて被覆２が形成され、被覆２を海水等に曝して長年使用された後、検査によっ被覆損傷部２ａが発見されたため、被覆損傷部２ａのところに新たな樹脂被覆を再形成する、という補修処理を説明する。
【００２０】
母材１は、鋼管や，ステンレス鋼管，ダクタイル鋳鉄管などの鉄鋼系管材が典型的であるが、鉄鋼系の板材や、あるいは銅系など非鉄金属製の部材でも良く、更にはアルミナなどセラミック製の管体等であっても良い。
被覆２を形成している材料は、ポリエチレンが典型的であるが、その他の熱可塑性樹脂、更には反応硬化性樹脂であっても良く、例えばポリプロピレンや，ポリオレフィン，ポリアミド，フッ素樹脂，ポリエステル，ポリウレタン，エポキシ樹脂，フェノール樹脂なども用いられる。これらの樹脂には、多くの場合、耐候性向上等のため、カーボンブラックや，酸化チタン等の顔料が配合されている。ポリエチレンの場合、通常は融点１２０℃〜１３０℃のものが使用されている。被覆２の厚さは、ポリエチレンの場合、大抵、１ｍｍ〜３ｍｍである。
【００２１】
このような被覆損傷部２ａの補修では、下地の精整処理と脱水処理と清浄処理と被覆層形成操作とが、その順に行われる。
先ず、精整処理では（図１（ｂ）参照）、被覆２のうち被覆損傷部２ａとその周りの被覆が除去されて、母材１の表面が露出し、被覆欠落部２ｂが形成される。被覆欠落部２ｂの縁には、その部分の断面がテーパ状になるよう、緩い傾斜が付けられる。そして、この被覆欠落部２ｂと周辺被膜２ｃとを合わせた領域が補修対象領域となる。
【００２２】
次の脱水処理では（図１（ｃ）参照）、被覆欠落部２ｂとその周りの周辺被覆２ｃとが加熱される。この加熱は、周辺被覆２ｃに吸収された余分な水分を蒸発させて除去するためなので、含水の突沸を招かないような温度で、被覆２側から、行われる。具体的には、後述する脱水処理装置１０の作用部２０のシール部材２２を被覆２上に当接させて、加熱部位すなわち脱水対象部位である被覆欠落部２ｂ及び周辺被覆２ｃを、囲体２１で囲い、加熱源４０から赤外線を照射して加熱し、通気手段３０にて通気する。その通気に際しては、脱水能率向上のため、囲体２１内に温風又は熱風を通気しながら、囲体２１内を減圧させるような排気も行う。
【００２３】
清浄処理では（図１（ｄ）参照）、サンディング等が行われて、被覆欠落部２ｂにおける母材１の表面酸化膜や、周辺被覆２ｃ表面の変性層が、除去される。周辺被覆２ｃは約５０ｍｍ幅の環状領域が清浄にされる。
ここまでの各処理すなわち精整処理と脱水処理と清浄処理は、前処理なので、被覆欠落部２ｂに被覆材を付けない状態で行われる。そして、周辺被覆２ｃに膨れ等の不良が生じていないことを確認したら次の主処理を行う。
【００２４】
被覆層形成操作は（図１（ｅ）参照）、被覆欠落部２ｂに被覆材を付けて行われる。すなわち、被覆欠落部２ｂ及び周辺被覆２ｃを補修用被覆材３にて覆うとともに、母材１の裏面（図では下側の面）から母材１を加熱する。被覆材３は、被覆２と全く同質のものでも，一部変性させたものでも，異質のものでも良く、要は被覆２と融着ないしは接着する被覆用樹脂であれば良い。その形態は、粉体でも（例えば特許文献１，３，４参照）、粉体樹脂成形シート（例えば特許文献２参照）でも、良い。被覆材３を密着させて取り付けることができれば、押圧器具や，吹付装置，給排装置などのライニング用具４（例えば特許文献１〜４参照）は用いても用いなくても良い。
【００２５】
母材１を加熱する加熱装置５は、誘導加熱装置が使い易いが、被覆２と被覆材３とを融着させるためにそれらの融点まで母材１を加熱できれば、他の装置や加熱手法でも良く、例えば火炎加熱や電熱線からの伝熱加熱でも良い。
こうして、この樹脂被覆の補修方法にあっては、被覆欠落部２ｂを被覆し周辺被覆２ｃに重なる新たな樹脂被覆が形成される。
なお、被覆材３がエポキシ樹脂など反応硬化性樹脂の場合、特に、液状塗料を用いて被覆層形成を行う場合、その施工に際して前記水分の突沸が起るような加熱を行わないことも多いが、その場合でも、脱水処理を含んだ前処理を行うことで、補修であっても新規被覆と同等の強い接着力が安定して示される。
【００２６】
また、上述の補修方法では、脱水処理に際して補修対象領域の被覆欠落部２ｂ及び周辺被覆２ｃを囲って加熱したが、補修対象領域を開放した状態で脱水処理を行っても良い。例えば、ポールやアーム等で加熱源４０を支持して補修対象領域を加熱するようにしても良い。さらに、通気は、扇風機を用いた送風等で行うようにしても良く、ドライヤー等を用いて温風を吹き付けるのも良い。
【００２７】
また、上述の補修方法では、脱水処理時には被覆側からだけ加熱し被覆層形成操作時には母材裏面側からだけ加熱したが（この方式には、各工程の加熱手段がより好適な方の手法に一元化されることで各工程毎の温度制御等が簡単になるとか、あるいは、時間のかかる脱水処理には安価な赤外線源付き装置の複数基を複数の補修個所に並列的に適用して脱水処理の能率を上げたりできるといった利点がある）、脱水処理時にも被覆層形成操作時にも被覆側からだけ加熱するようにしても良く、脱水処理時にも被覆層形成操作時にも母材裏面側からだけ加熱するようにしても良い（これらの方式には加熱手段が一つだけで済むという利点がある）。母材裏面からの入熱だけでも、伝熱によって、被覆が加熱される。あるいは、脱水処理時には被覆側と母材裏面側との両方から加熱し被覆層形成操作時には母材裏面側からだけ加熱するようにしても良く、脱水処理時には被覆側からだけ加熱し被覆層形成操作時には被覆側と母材裏面側との両方から加熱するようにしても良く、脱水処理時にも被覆層形成操作時にも被覆側と母材裏面側との両方から加熱するようにしても良い（被覆側と母材裏面側との両方から加熱することにより、脱水処理や被覆層形成操作の所要時間が短縮される）。
【００２８】
図２に示した脱水処理装置１０を詳述する。図２は、（ａ）が脱水処理装置１０全体の斜視図、（ｂ）が作用部２０を斜め下から見上げた斜視図、（ｃ）が作用部２０の正面図、（ｄ）が作用部２０の縦断端面図である。
【００２９】
この脱水処理装置１０は、囲体２１を主体とする作用部２０と、それにフレキシブルな配管で連通接続された通気手段３０と、加熱源４０とそれに給電線で接続された電源ユニット４１とからなる加熱手段と、電源ユニット４１と放射温度計５１とに信号ケーブルで接続されたコントローラ５０とを備えている。そのうち加熱源４０と放射温度計５１は、囲体２１に内蔵されて、囲体２１の内底（図示の姿勢では天井）に装着されている。通気手段３０と電源ユニット４１とコントローラ５０は、作用部２０から離して設置しうるようになっている。
【００３０】
囲体２１は、丈夫で耐熱性や気密性にも優れた例えばフェノール樹脂（例えばベークライト）の板から作られ、概ね直方体状に形成されるが、その一面は開放されて開口２３を成している。開口２３の縁のなす囲体２１の端部（図では下端）には、シール部材２２が一巡して付設されていて、作用部２０を補修対象物に当接させたとき囲体２１内の空間を気密にできるようになっている。なお、必須でなく図示を割愛したが囲体２１には運搬用のアイボルトや，把手，固定治具取付用突片なども適宜付設される。
【００３１】
通気手段３０は、絞り弁３１とヒータ３２（吸気加熱手段）と給気管３３とからなり外から囲体２１の中へ空気を導き入れる給気手段と、排気管３４とブロワー３５とからなり囲体２１の中から外へ空気を排出する排気手段とに大別される。通気の量と減圧の程度は、絞り弁３１での絞り具合とブロワー３５の運転状態によって、設定や調節がなされ、その通気の量とヒータ３２の通電量とによって、囲体２１に送り込まれる空気の温度が設定・調節されるようになっている。もっとも、このような構成は一例にすぎず、ブロワー３５は、排気側ではなく給気側に配置されてもよいし、給排気両方に配置されても良い。ブロワー３５として掃除機を用いることもできる。
【００３２】
加熱源４０は、赤外線ランプや遠赤外線ランプが使い易いが、開口２３から赤外線を含む光線を照射できれば他の発熱源でも良く、一様な照射を能率良く行うべく例えば囲体２１の内底に複数個が列設される。
電源ユニット４１は、コントローラ５０の制御に従って、加熱源４０への給電を断続することで或いは給電量を加減することで、加熱状態を調節する。
放射温度計５１も、囲体２１の内底に設けられるが、これは、被覆欠落部２ｂでなく周辺被覆２ｃの表面温度を測定するよう、隅の方に設置される。その測定値（温度Ｔｃ）がコントローラ５０に随時送出されるようになっている。
【００３３】
コントローラ５０は、プログラマブルなコンピュータやシーケンサ等からなり、温度Ｔｃを監視して、それが目標値になるよう、加熱源４０の動作制御を行う。制御方式は、固定値制御に限らず、目標値可変の追従制御でも、単純な比例制御でも、それより複雑なＰＩＤ制御や最適制御でも良い。温度Ｔｃが画面に数値やグラフで表示されるようにもなっている。
【００３４】
このような脱水処理装置１０は、上述したように脱水処理で使用され（図１（ｃ）参照）、その際には、作用部２０のシール部材２２が被覆欠落部２ｂ及び周辺被覆２ｃを囲いながら被覆２表面に密着させられ、通気手段３０の通気状態が調節され、加熱源４０の動作がコントローラ５０によって制御される。
そして、例えば、囲体２１の内部空間が約１００Ｌで、被覆２が融点１２５℃のポリエチレンの場合、通気量は約０．１Ｌ／ｓ、送風温度は約２０℃、減圧代は約０．０１ＭＰａ（すなわち大気圧≒０．１ＭＰａより少し低い０．０９ＭＰａ前後になっている）で、温度Ｔｃは１２５℃±２℃にされる。
この状態が、予備実験等にて既知となっている必要時間以上たとえば４時間に亘って維持され、それによって周辺被覆２ｃが十分に脱水する。
【００３５】
図３（ａ）に補修部位および作用部の縦断端面図とコントローラ等のブロック図を示した脱水処理装置６０を説明する。
【００３６】
この脱水処理装置６０が上述した脱水処理装置１０と相違するのは、母材裏面温度検出手段として熱電対６１が追加された点と、界面温度演算手段として推定演算ルーチンが追加された点である。
熱電対６１は、母材裏面１ｂの温度を測定するため、母材裏面１ｂに着脱しうるものが採用され又は適当な治具で母材裏面１ｂに取り付けられて、測定した温度Ｔｂをコントローラ５０に送出するようになっている。
【００３７】
推定演算ルーチンは、コントローラ５０に追加インストールされたプログラムであり、これによって、コントローラ５０は、熱電対６１で測定した温度Ｔｂと放射温度計５１で測定した温度Ｔｃとから周辺被覆２ｃと母材１との境界面の推定温度Ｔａを算出するようになっている。メニュー選択画面やパラメータ設定画面などで、母材１の材質および厚さと、被覆２の材質および厚さとを入力すると、熱伝達率Ｋｂ，Ｋｃがデータベース等から求められ、それを用いた適宜な算出式たとえば比例按分の式［Ｔｂ＋（Ｔｃ−Ｔｂ）×Ｋｃ／（Ｋｂ＋Ｋｃ）］等を用いて温度Ｔａが算出される。また、コントローラ５０は、温度制御ルーチンが、温度Ｔａを目標値に追従させるよう一部改造されている。さらに、制御目標が、横軸に時間を採り縦軸に温度を採ったグラフで設定できるようにも改造されている（図３（ｂ）〜（ｄ）参照）。
【００３８】
このような脱水処理装置６０を脱水処理で使用すると、きめ細かく温度Ｔａを制御することが可能となり、含水の突沸を確実に回避しつつ周辺被覆２ｃを十分に脱水させることができる。
例えば（図３（ｂ）参照）、温度Ｔａを、先ず水の沸点より少し低い一定温度に一定時間だけ維持し、次いで、被覆２の融点より少し低い温度に上げて維持することができ、そうすることにより、高い確度で適切な脱水がなされる。
【００３９】
また（図３（ｃ）参照）、温度Ｔａの推定誤差の悪影響を軽減する等のために、沸点近傍での温度Ｔａを、沸点より少し低い温度，沸点に等しい温度，沸点より少し高い温度の３段階に変化させることもできる。
さらに、（図３（ｄ）参照）、周辺被覆２ｃの断面テーパ部分の過熱を回避する等のために、沸点近傍までの温度Ｔａの立ち上がりを緩やかなものにすることもできる。
【００４０】
図４に示した脱水処理装置７０を説明する。図４は、その構成を示し、（ａ）が補修部位および作用部２０の縦断端面図とコントローラ５０等のブロック図、（ｂ）がコントローラ５０の処理の概要フローチャートである。
【００４１】
この脱水処理装置７０が上述した脱水処理装置１０と相違するのは、含水率検出手段として容量センサ７１及び含水率測定器７２が追加された点と、コントローラ５０が脱水状態判別手段および脱水処理停止手段として機能するようプログラム改造がなされた点である。
容量センサ７１と含水率測定器７２は、周辺被覆２ｃの誘電率が含水率に応じて変わることに基づき、容量センサ７１を周辺被覆２ｃに添着して含水率測定器７２を作動させると、含水率対応物理量として静電容量を測定し、所定の演算を行って含水率Ｗを求め、これを検出結果としてコントローラ５０に随時送出するようになっている。
【００４２】
コントローラ５０は、脱水処理として上述の温度制御を行うのに加え、それと並行して（図４（ｂ）参照）、含水率Ｗに基づいて周辺被覆２ｃの脱水状態が被覆層形成操作に適う程であるか否かを判別するとともに（ステップＳ１，Ｓ２）、その判別結果に基づいて脱水処理を停止する（ステップＳ３〜Ｓ５）。
具体的には、含水率測定器７２から含水率Ｗを入力し（ステップＳ１）、これが所定の閾値αより小さくなったかを調べる（ステップＳ２）。含水率Ｗが閾値αより大きいか等しい間は（ステップＳ２のＮｏ）、含水率Ｗのチェックを繰り返す（ステップＳ１，Ｓ２）。
【００４３】
含水率Ｗが閾値αを下回ったときは（ステップＳ２のＹｅｓ）、待ち時間を設定し（ステップＳ３）、その時間が経過するのを待って（ステップＳ４）、脱水処理を停止する（ステップＳ５）。脱水処理の停止は、制御ルーチンに指示して電源ユニット４１から加熱源４０への給電を止めるのでも良く、脱水した旨の画面表示や音声での案内を行ってオペレータに停止操作を催促するのでも良い。待ち時間は、含水率Ｗの測定誤差等による脱水不足を確実に無くすためのものであり、不要のときはゼロにされる。また、閾値αは、被覆２の材質等に基づいて設定されるものであり、例えば、ポリエチレンでは０．０３mass％程度にされる。
【００４４】
このような脱水処理装置７０を脱水処理で使用することにより、周辺被覆２ｃの脱水状態がリアルタイムで的確に把握され、それに基づいて、周辺被覆２ｃが脱水したときには十分な脱水状態を確認したうえで、脱水処理が停止される。そのため、余分な脱水処理が切り上げられるので、その分だけ脱水処理が短縮される。しかも、脱水不足の心配も無い。
【００４５】
図５に示した脱水処理装置を説明する。図５は、その構造を示し、（ａ）が作用部２０を斜め上から見下ろした斜視図、（ｂ）が作用部２０を斜め下から見上げた斜視図、（ｃ）が或るアダプタ８０の斜視図、（ｄ）がそのアダプタ８０の正面図、（ｅ）がそのアダプタ８０の側面図、（ｆ）が別のアダプタ９１の側面図、（ｇ）が他のアダプタ９１の側面図である。
【００４６】
この作用部２０が上述したものと相違するのは、囲体２１が角形から円筒状に改造された点と、囲体２１に着脱されるアダプタ８０が追加された点である。アダプタ９０，９１も追加されている。
囲体２１は（図５（ａ），（ｂ）参照）、一端が閉塞され他端が開放された円筒体からなり、開放端２１ａには赤外線照射のための開口２３が形成されている。また、開放端２１ａの近傍には、囲体２１の外周面を一周するリング８３が装着されている。
【００４７】
アダプタ８０は（図５（ｃ）〜（ｅ）参照）、両端開放の短い筒体からなり、上端８１（他端）は平らに切り落としたままであるが、下端（一端）は、湾曲して切り落とされて鞍の縁の形状になっており、ここにはシール部材２２が装着されている。アダプタ８０の外周面にはフック８２も取り付けられている。アダプタ８０の内径は囲体２１の外径より僅かに大きく形成されており、そのため、開放端２１ａを上端８１に差し込んで、フック８２をリング８３に掛けると、アダプタ８０が作用部２０に装着されて、上端８１が開口２３のところに連結されるようになっている。逆に、フック８２をリング８３から外せば、アダプタ８０を囲体２１から取り外せるようになっている。
【００４８】
アダプタ９０，９１も、アダプタ８０と同様のものであるが、シール部材２２装着端部の湾曲状態（鞍の縁の形状）が少し異なっている。具体的には、アダプタ８０は大径管の外周面にフィットするよう湾曲が緩やかで、アダプタ９０は小径管の外周面にフィットするよう湾曲が強くなっている。アダプタ９１の下端は管内面にフィットするような鞍の縁の形状になっている。
【００４９】
このような脱水処理装置の使用態様を図５（ｈ）の斜視図を引用して説明する。この場合、脱水処理で使用する囲体２１に着脱可能な複数・多数のアダプタ８０，９０，９１のうちから、被覆２を補修しようとする母材１の管径に適合するもの例えばアダプタ８０を選出し、これを囲体２１に装着する。それから、シール部材２２を母材１の補修部位の周りに密着させる。その際、配管が邪魔になるような場合には、フック８２を弛めて囲体２１を軸回転させて、配管の向きを変えると良い。後は、上述したのと同様にして、脱水処理が行われる。
【００５０】
径の異なる他の管の外周面を補修するときには、作用部２０からアダプタ８０を外して代わりに例えばアダプタ９０を装着する。管の内周面を補修するときには、作用部２０に例えばアダプタ９１を装着する。
こうして、この樹脂被覆の脱水処理装置にあっては、アダプタの付け替えによって、平板に限らず、いろいろな径の管材に、同じ装置を共用することができるので、便利で経済的である。
【００５１】
図６に示した脱水処理装置１００を説明する。図６は、その構造および使用方法を示し、（ａ）が装置全体の斜視図、（ｂ）が補修部位および作用部の縦断端面図である。
この脱水処理装置１００が上述した脱水処理装置１０と最も相違するのは、作用部２０から加熱源４０が取り除かれた点である。
これに伴い、温風・熱風を被覆欠落部２ｂと周辺被覆２ｃへ的確に吹き付けるために、給気管３３の先端が囲体２１の内部へ入り込んで、或いは給気管３３の延長部材に相当する筒状部材が囲体２１の内部に追加されて、その吹出口が開口２３の中央に向けられている。
【００５２】
また、コントローラ５０による温度管理は、ヒータ３２の発熱量を可変制御することで行われるようになっている。さらに、ブロワー３５が、絞り弁３１のあったところ即ち給気管３３側に移って、送風を行うようになっている。ブロワー３５に代わって排気塔３６が排気管３４に連結されている。排気塔３６は、煙突状のもので、排気を上空へ放出するようになっているが、温風・熱風を作用部２０から直に放出しても良い状況下では不要である。囲体２１内を減圧しない構成であって多少の空気漏れは問題にならないのでシール部材２２も省かれている。
【００５３】
このような脱水処理装置１００を脱水処理で使用すると、給気管３３から被覆欠落部２ｂ及び周辺被覆２ｃに温風・熱風が吹き付けられ、この温風・熱風によって補修部位の脱水が行われる。赤外線照射等による加熱は無いので、処理時間の短縮には通気温度が高めにされる。排気は排気塔３６にて上空へ向けて放出されるので、本装置の作用部２０は管内でも使用可能である。囲体２１内の減圧が無くなり、それに伴って開口２３のところで負圧吸引力が働くことも無くなって、作用部２０が補修部位に吸着することも無いため、管内面に使用するときは例えば伸縮治具を突っ張らせて作用部２０を固定したり、管外面に使用するときは例えばワイヤー等の締結具で作用部２０を固定したり、平板に使用するときは例えば重石で作用部２０を固定すると良い。
【００５４】
なお、この脱水処理装置１００についても、脱水処理装置６０の如く、突沸の確実な回避のため、母材裏面温度検出手段としての熱電対６１や界面温度演算手段としての推定演算ルーチンを追加して、きめ細かな温度制御を行うようにしても良い。
また、脱水処理装置７０の如く、脱水処理の短縮のため、含水率検出手段としての容量センサ７１及び含水率測定器７２や脱水状態判別手段および脱水処理停止手段として機能するプログラムを追加して、周辺被覆２ｃの脱水状態がリアルタイムで把握されるようにしても良い。
さらに、図５の脱水処理装置の如く、囲体２１をアダプタ８０，９０，９１等と着脱自在なものに改造して、種々の径の管体補修に共用できるようにしても良い。
【００５５】
【実施例】
被覆層形成操作に先だって脱水処理を行うことの有効性を確認するために、含水テストピースを作成して、その被覆２に脱水処理装置１０を作用させ、脱水処理後の外観を調べた。
テストピースは、１５０ｍｍ×９０ｍｍ×９ｍｍの鋼板を母材１とし、これに融点１２５℃のポリエチレンを被覆して２ｍｍ厚さの被覆２を形成した後、５０℃の海水槽内に浸漬したものである。浸漬期間は約６ヶ月である。
【００５６】
脱水処理装置１０は、開口２３が５００ｍｍ×５００ｍｍで、加熱源４０には、３００Ｗの赤外線ランプが４個採用されている。これらのランプは、被覆２から１００ｍｍ〜２００ｍｍ程度たとえば１５０ｍｍ離れたところに設置されて、開口２３内をほぼ一様に加熱するようになっている。通気手段３０にて、送風するときは、約２０℃の乾燥空気を約０．１Ｌ／ｓの流量で供給し、減圧するときは、大気圧から０．０１ＭＰａほど低くなるようにした。
【００５７】
そして、被覆２表面の水分は拭き取っても脱水処理を省いて被覆層形成操作を行ったときには、被覆２の下に膨れが多数発生して、外観不良が明白であった。また、脱水処理は行っても、被覆２の融点１２５℃を超える１３０℃に被覆表面温度を０．５時間保持したときは、被覆２の表面に凹凸が発現するとともに、被覆２が劣化したため、被覆層形成操作を行うに至らなかった。
これに対し、被覆２の表面温度を融点１２５℃以下に保持する脱水処理を行ったときは、脱水処理で異常発生が無いので被覆層形成操作を行ったが、脱水処理時の被覆表面温度と保持時間などの条件によって、被覆層形成操作で不具合が発生する場合と発生しない場合とがある。
【００５８】
具体的には、脱水処理で被覆２の表面温度を１１５℃に５時間保持したときは、後の被覆層形成操作で被覆２の下に膨れが発生して外観不良が見つかった。これは脱水不足と見られる。
被覆２の表面温度を同じ１１５℃に保持する脱水処理でも、１０時間保持すると、被覆層形成操作で被覆２の下に発生する膨れが少なくなり、不具合の程度が軽減されたが、まだ脱水不足と見られる。
脱水処理で被覆２の表面温度を１１５℃に保持する時間がより長期の２４時間に及んだときは、良好な補修結果が得られ、十分に脱水したものと見られる。
【００５９】
また、脱水処理で被覆２の表面温度を１２０℃に５時間保持したときは、後の被覆層形成操作で被覆２の下に少し膨れが発生して外観不良となった。これも脱水不足と見られる。
被覆２の表面温度を同じ１２０℃に保持する脱水処理でも、１０時間保持したときは、良好な補修結果が得られ、十分に脱水したものと見られる。
【００６０】
さらに、脱水処理で被覆２の表面温度を１２５℃に４時間しか保持しなかったときは、被覆層形成操作で被覆２の下に少し膨れが発生して外観不良となった。しかし、脱水処理で被覆２の表面温度を１２５℃に５時間保持したときは、良好な補修結果が得られ、十分に脱水したものと見られる。
被覆２の表面温度を同じ１２５℃に保持する脱水処理でも、送風を併用したときは４時間で、減圧も併用したときは３．５時間で、十分に脱水して、良好な補修結果が得られた。
【００６１】
【その他】
母材に対する直接入熱は、誘導加熱やガス加熱といった大入熱加熱手段の他、赤外線を照射する加熱方法も、有用である。前者の大入熱加熱には、加熱を能率良く行えるという利点があるのに対し、後者の赤外線照射加熱には、比較的簡単で制御性にも優れた装置が使えて簡便に行えるという利点がある。両者の併用も可能であり、例えば樹脂被覆の加熱に赤外線加熱と誘導加熱を併用すると、表裏両面から入熱されるため、伝熱時間が片面加熱の１／４（過渡期）〜１／２（定常期）に短縮される。これにより、熱伝導しにくい樹脂被覆では、大きなメリットを享受することができる。また、異種の又は同種の装置を並列に設置して、同時稼動あるいは交互稼動させても良い。
【００６２】
赤外線源の具体例としては、近年多用されている可視光成分の感知し難い遠赤外線源の他、可視光混じりの赤熱ヒーターや、赤色電球、白熱電球が挙げられる。
赤外線吸収率の高い塗料としては、カーボン入りの塗料が使い易い。金属母材は、一般に赤外線吸収率が数％しかないので、そのままでは赤外線照射加熱を使いずらいが、上述の塗料で黒塗りすることで、赤外線照射加熱を能率良く行うことができる。なお、樹脂被覆は一般に赤外線吸収率が数十％と高いので、そのままでも赤外線照射加熱に適している。
【００６３】
【発明の効果】
以上の説明から明らかなように、本発明の樹脂被覆の補修方法にあっては、脱水処理を被覆層形成操作に先行させることにより、適切な補修をやり直し不要で確実に行えることとなる。
また、脱水処理では被覆側から加熱し被覆層形成操作では母材側から加熱することや、脱水処理で加熱部位を囲って減圧すること、脱水処理で加熱部位を囲って又は開放して通気すること、通気する際に温風又は熱風を通気することも行うことにより、補修部位の脱水が能率良く行えることとなる。
【００６４】
また、本発明の樹脂被覆の脱水処理装置にあっては、囲体に加熱源と給排気手段とを組み合わせて、局所加熱による脱水ばかりか通気による水蒸気除去も行われるようにもしたことにより、被覆層形成操作に先行する脱水処理が能率良く行われて、的確な樹脂被覆の補修方法の実行に役立つ。
また、本発明の他の樹脂被覆の脱水処理装置にあっては、囲体への通気に際して温風・熱風が供給されるようにもしたことにより、脱水能率が一層良くなる。さらに、本発明の別の樹脂被覆の脱水処理装置にあっては、囲体に供給された温風・熱風によって脱水対象部位が加熱されるようにしたことにより、被覆層形成操作に先行する脱水処理が能率良く行われて、的確な樹脂被覆の補修方法の実行に役立つ。
【００６５】
また、境界面の温度を推定して沸点以下に抑えるようにもした脱水処理装置にあっては、被覆下の過熱が確実に回避されて、被覆層形成操作に先行する脱水処理が能率良く且つ的確に行われる。また、含水率を検出して脱水状態を判別するようにもした脱水処理装置にあっては、無駄な脱水処理が省かれて、被覆層形成操作に先行する脱水処理が極めて能率良く行われる。また、着脱式アダプタを備えた脱水処理装置にあっては、径の異なる被覆管に共用可能となって、被覆層形成操作に先行する脱水処理が能率良く且つ簡便に行える。
【図面の簡単な説明】
【図１】本発明の樹脂被覆の補修方法について、（ａ）〜（ｅ）何れも補修部位の縦断端面図である。
【図２】本発明の樹脂被覆の脱水処理装置について、（ａ）が装置全体の斜視図、（ｂ）が作用部を斜め下から見上げた斜視図、（ｃ）が作用部の正面図、（ｄ）が作用部の縦断端面図である。
【図３】本発明の樹脂被覆の脱水処理装置について、（ａ）が補修部位および作用部の縦断端面図とコントローラ等のブロック図、（ｂ）〜（ｄ）が何れも温度変化のグラフである。
【図４】本発明の樹脂被覆の脱水処理装置について、（ａ）が補修部位および作用部の縦断端面図とコントローラ等のブロック図、（ｂ）がコントローラの処理の概要フローチャートである。
【図５】本発明の樹脂被覆の脱水処理装置について、（ａ）が作用部を斜め上から見下ろした斜視図、（ｂ）が作用部を斜め下から見上げた斜視図、（ｃ）が或るアダプタの斜視図、（ｄ）がそのアダプタの正面図、（ｅ）がそのアダプタの側面図、（ｆ）が別のアダプタの側面図、（ｇ）が他のアダプタの側面図、（ｈ）がアダプタ使用状態の斜視図である。
【図６】本発明の樹脂被覆の脱水処理装置について、（ａ）が装置全体の斜視図、（ｂ）が補修部位および作用部の縦断端面図である。
【符号の説明】
１母材（鋼板、鋼管、樹脂被覆の対象物）
１ａ境界面（接合面、被覆下面、母材表面）
１ｂ母材裏面
２被覆（熱可塑性樹脂層、防食被覆層、樹脂被覆）
２ａ被覆損傷部（補修必要部位）
２ｂ被覆欠落部（補修対象部位、加熱部位）
２ｃ周辺被覆（被覆欠落部の周り、加熱部位、脱水対象部位）
３被覆材（シート状樹脂、粉体樹脂、熱可塑性樹脂）
４ライニング用具（吹付装置、押圧器具、給排装置）
５加熱装置（誘導加熱、火炎加熱、伝熱加熱、融着用加熱手段）
１０脱水処理装置（樹脂被覆の脱水処理装置）
２０作用部（補修対象部位への設置部分）
２１囲体（箱体、殻体、筒体、補修対象部位を囲う部材）
２２シール部材（当接端部気密手段）
２３開口（赤外線照射口）
３０通気手段（給気手段、排気手段、減圧手段、温風・熱風供給手段）
３１絞り弁（給気手段、減圧手段）
３２ヒータ（給気手段、給気加熱手段）
３３給気管（送風用配管、給気手段）
３４排気管（減圧用配管、排気手段）
３５ブロワー（排気手段、減圧手段）
４０加熱源（赤外線ランプ、赤外線出射手段）
４１電源ユニット（加熱調整部）
５０コントローラ（演算手段、判別手段、制御手段）
５１放射温度計（被覆表面温度検出手段）
６０脱水処理装置（樹脂被覆の脱水処理装置）
６１熱電対（母材裏面温度検出手段）
７０脱水処理装置（樹脂被覆の脱水処理装置）
７１容量センサ（含水率対応物理量測定手段、含水率検出手段）
７２含水率測定器（物理量変換部、含水率検出手段）
８０アダプタ（筒体）
８１上端（囲体の開口のところに連結される他端）
８２フック（囲体とアダプタとの着脱手段）
８３リング（囲体とアダプタとの着脱手段）
９０アダプタ（筒体）[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resin coating repair method and a dehydration apparatus, and more particularly to a technique for re-forming a resin coating on a damaged portion when a resin-coated steel pipe or the like is used and the coating is damaged.
[0002]
[Prior art]
When applying an anti-corrosion coating (lining) to the exposed metal part, powder resin is selected as a raw material for the coating material, the exposed metal part is heated from the back side, and a powder is applied to the exposed metal surface and its surroundings using a spraying device. An anticorrosion coating construction method for spraying resin is known (see, for example, Patent Documents 1 and 4).
In addition, when coating a metal strip or the like with a resin, a technique is known in which a coating powder resin is formed into a porous sheet, applied to a coating target, and heated and melted to form a resin coating layer. (For example, refer to Patent Document 2).
Furthermore, when forming the resin coating layer on the inner surface of the metal tube, there is known a method of filling and heat-sealing the powder resin to the coating target site while sucking or removing air from the coating target site. (For example, refer to Patent Document 3).
[0003]
These can be applied to flat steel plates and straight steel pipes, as well as resin-covered parts that remain locally without being covered during new construction (for example, welds), joints, branching parts, curved parts It can also be applied to parts and the like, and is also applied to repair of damaged parts of the coating.
Furthermore, when repairing a damaged part of a resin-coated metal member, the damaged part is removed, and the part of the part that is not covered and the normal part around it are used as the repair target area. The resin coating is then re-formed using the above-described technique.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 01-310663 (first page, FIG. 1)
[Patent Document 2]
Japanese Patent Laid-Open No. 62-242519 (first page, FIGS. 1 to 10)
[Patent Document 3]
JP-A-60-222177 (1st page, FIG. 1)
[Patent Document 4]
JP-A-60-110368 (first page, FIG. 2)
[0005]
[Problems to be solved by the invention]
However, unlike the new coating formation, in the repair after use, a defect may occur in the reformed coating of the repaired part or the existing coating in the vicinity thereof. Specifically, unevenness appears in the coating, a part of the coating peels off from the base material, and so on. Conventionally, such a defect is interpreted as occurring due to leaving the damaged coating without removing it as a normal coating without noticing the damage inside the coating, and removing the re-formed coating. Then, the existing coating around it was also removed to widen the missing portion of the coating, and then the coating was reformed again.
[0006]
However, as a result of many years of repair work and the accompanying investigations and analyses, it was found that the cause of the above-mentioned problems was that the moisture content of the coating was greater than the oversight of internal damage. did. When water is absorbed due to long-term water use or use in water, and the moisture content of the coating increases to near 0.1 mass%, it is heated to around 250 ° C. during heating for coating fusion In many cases, the moisture contained in the coating suddenly boils, causing swelling under the coating, in the coating layer, or between the coating layers, and the probability of occurrence of unevenness or partial peeling of the coating increases. It is.
The present invention has been created based on such knowledge, and an object thereof is to realize an accurate method for repairing a resin coating.
Another object of the present invention is to realize a tool suitable for executing such a repair method.
[0007]
[Means for Solving the Problems]
The resin coating repair method according to claim 1 of the present invention, which has been devised to solve such a problem, is provided with a coating missing portion for repairing a coating missing portion occurring in a member having a resin coating. Before re-forming the resin coating on the repair target area set to be included, the existing resin coating in the repair target area is heated and coated prior to the coating layer forming operation in which the resin material is spread in layers. A dehydration process is performed to expel the moisture inside.
[0008]
In such a resin coating repair method, the dehydration process is performed prior to the coating layer forming operation, and the coating missing part and its surroundings are heated by this dehydration process. Then, the existing coating remaining around the coating missing portion is dehydrated not only from the coating surface but also from the inside of the coating and the boundary surface / joint surface under the coating.
As a result, even if heating for fusion is performed in the coating layer forming operation, bumping of water does not occur, so that undesired coating irregularities and the like do not occur. Further, even when repair is performed by performing coating or the like without heating in the coating layer forming operation, the adhesiveness is improved. For this reason, appropriate repairs can be performed reliably without the need for redoing.
Therefore, according to the present invention, an accurate resin coating repair method can be realized.
[0009]
A repair method for a resin coating according to claim 2 of the present invention is the repair method for the resin coating described above, comprising a method of directly applying heat to the coating by irradiating the coated surface with infrared rays, and a base of the coating A method of directly inputting heat into the base material to be heated and transferring the heat to the coating on the base material, and performing heating for re-forming the resin coating in the repair target region.
The repair method for a resin coating according to claim 3 of the present invention is the repair method for the resin coating described above, wherein in the dehydration treatment, the infrared ray is irradiated to the coated surface and heated, and in the coating layer forming operation, It is characterized in that the base material is directly heated and heated.
[0010]
A repair method for a resin coating according to claim 4 of the present invention is the repair method for a resin coating described above, wherein the mother of the base of the coating covers both the dehydration treatment and the coating layer forming operation. Heat is directly applied to the material, and the heat is transferred to the coating on the base material, whereby heating for re-forming the resin coating on the repair target region is performed.
The repair method for the resin coating according to claim 5 of the present invention is the repair method for the resin coating, wherein direct heat input to the base material is performed by a large heat input heating means such as induction heating. Features.
A repair method for a resin coating according to claim 6 of the present invention is a repair method for the resin coating described above, wherein a coating material having an infrared absorption rate higher than that of the base material is applied to the base material, and infrared (including infrared rays) is applied thereto. In other words, the base material is directly subjected to heat input.
[0011]
According to a seventh aspect of the present invention, there is provided a method for repairing a resin coating, wherein the resin coating is repaired by depressurizing a heated portion in the dehydration process.
A repair method for a resin coating according to claim 8 of the present invention is the above-described repair method for a resin coating, characterized in that the dehydration treatment encloses a heated portion and ventilates.
A repair method for a resin coating according to claim 9 of the present invention is the repair method for a resin coating described above, wherein the dehydration treatment vents the heated portion in an open state.
A repair method for a resin coating according to claim 10 of the present invention is the repair method for the resin coating described above, wherein hot air or hot air is ventilated when ventilating.
By performing any one of these or using a plurality of these in combination, dehydration of the repair site can be performed efficiently.
[0012]
The resin-coated dehydration apparatus according to claim 11 of the present invention devised as a tool suitable for execution of such a repair method stores a heating source that emits infrared rays (including visible rays including infrared rays). And an enclosure (box-like or shell-like) in which an opening for irradiating the infrared rays is formed around the coating missing portion of the base material constituting the base of the member having a resin coating, The air supply means for supplying air to the enclosure and the exhaust means for exhausting from the enclosure are provided.
[0013]
In such a resin-coated dehydration processing apparatus, the enclosure is applied to the coating surface of the member having the resin coating and used for dehydration. At this time, the opening surrounds the coating missing part and the surrounding area. It is operated by. If it does so, the infrared rays emitted from the heating source are concentrated and irradiated to the dehydration target site without being dissipated outside the system. As a result, the coating around the missing coating portion is heated, and moisture is evaporated therefrom (evaporation of moisture from the coating surface and diffusion replenishment of moisture in the coating to the coating surface are promoted by heating). The water vapor jumps one after another into the enclosure, but is immediately carried out by the ventilation of the enclosure by the air supply means and the exhaust means. Thereby, the dehydration process preceding the coating layer forming operation is efficiently performed. Therefore, according to the present invention, it is possible to realize a dehydration apparatus suitable for executing an accurate resin coating repair method.
[0014]
According to a twelfth aspect of the present invention, there is provided a resin-coated dewatering apparatus according to the above-described dewatering apparatus, wherein an air supply heating means is added to the air supply means.
In such a resin-coated dewatering apparatus, warm air and hot air are sent in when ventilating the enclosure, so that the dewatering efficiency is further improved.
[0015]
Furthermore, the resin-coated dewatering apparatus according to claim 13 of the present invention includes an enclosure in which a coating missing portion of a member having a resin coating and an opening for surrounding the enclosure are formed, and supply to the enclosure. An air supply means for supplying air, an air supply heating means attached to the air supply means, and an exhaust means for exhausting air from the enclosure.
In such a resin-coated dewatering apparatus, ventilation to the enclosure is performed, and warm air / hot air is sent at that time, and the dehydration target part is heated by the warm air / hot air. Since the water evaporates and the steam is carried by blowing air, the dehydration process preceding the coating layer forming operation is efficiently performed even if no heating source is built in the enclosure. Therefore, according to the present invention, it is possible to realize a dehydration apparatus suitable for executing an accurate resin coating repair method.
[0016]
According to a fourteenth aspect of the present invention, there is provided the dewatering apparatus for resin coating according to the above-described dewatering apparatus, comprising: a coating surface temperature detecting means for measuring a surface temperature of the coating around the coating missing portion. , A base material back surface temperature detecting means for performing temperature measurement on the back surface of the base material constituting the base of the resin coating (that is, the back surface when the surface where the coating lacking portion is present), and those Interface temperature calculating means for calculating an estimated temperature of a boundary surface between the coating around the coating missing portion and the base material (that is, a bonding surface under the coating) based on a detection result; and (at least at an initial stage) the estimated temperature Is provided with interface temperature control means for controlling the operation of one or both of the heating source and the supply air heating means so as to keep the temperature below the boiling point of water.
In such a resin-coated dewatering apparatus, overheating that may cause bumping under the coating is reliably avoided, so that the dewatering process prior to the coating layer forming operation is performed efficiently and accurately.
[0017]
Further, the resin-coated dewatering apparatus according to claim 15 of the present invention is the above-described dewatering apparatus, wherein the moisture content detecting means measures the moisture content-corresponding physical quantity for the coating around the missing coating portion. And a dehydration state determination means for determining whether or not the dehydration state is suitable for the coating layer forming operation based on the detection result, and the dehydration process is stopped based on the determination result or an introduction treatment for the purpose (for example, And dehydration stop means for performing stop reservation and stop prompting).
In such a resin-coated dehydration apparatus, if the dehydration is sufficient, a further unnecessary dehydration process is omitted, so that the dehydration process preceding the coating layer forming operation is performed very efficiently.
[0018]
The resin-coated dewatering apparatus according to claim 16 of the present invention is the above-described dewatering apparatus, comprising a cylindrical body detachably attached to the enclosure, wherein one end is formed in the shape of a rim. Is provided with an adapter connected to the opening when mounted on the enclosure.
In such a resin-coated dewatering apparatus, a simple and inexpensive adapter is easily replaced, so that the resin-coated dewatering apparatus can be easily used for cladding tubes having different diameters. Thereby, the dehydration process preceding the coating layer forming operation can be performed efficiently and easily.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates the method for repairing a resin coating according to the present invention in accordance with the procedure, and (a) to (e) are longitudinal end views of the repair site.
Here (see FIG. 1 (a)), the surface of the base material 1 (the upper surface in the figure) was previously resin-coated to form the coating 2, and the coating 2 was exposed to seawater and used for many years. Since the coating damaged part 2a was discovered by the inspection, a repair process of re-forming a new resin coating at the coating damaged part 2a will be described.
[0020]
The base material 1 is typically a steel pipe such as a steel pipe, stainless steel pipe or ductile cast iron pipe, but may be a steel plate or a non-ferrous metal member such as copper or a ceramic such as alumina. It may be a tube or the like.
The material forming the coating 2 is typically polyethylene, but may be other thermoplastic resins or further reaction curable resins, such as polypropylene, polyolefin, polyamide, fluororesin, polyester, polyurethane. Epoxy resins and phenol resins are also used. In many cases, pigments such as carbon black and titanium oxide are blended with these resins in order to improve weather resistance. In the case of polyethylene, one having a melting point of 120 ° C to 130 ° C is usually used. The thickness of the coating 2 is usually 1 mm to 3 mm in the case of polyethylene.
[0021]
In such repair of the damaged coating portion 2a, the ground preparation processing, dehydration processing, cleaning processing, and coating layer forming operation are performed in that order.
First, in the refining process (see FIG. 1B), the coating damaged portion 2a and the surrounding coating are removed from the coating 2, the surface of the base material 1 is exposed, and the coating missing portion 2b is formed. . The edge of the covering missing portion 2b is gently inclined so that the cross section of the portion becomes tapered. And the area | region which match | combined this covering missing part 2b and the peripheral coating 2c becomes a repair object area | region.
[0022]
In the next dehydration process (see FIG. 1C), the coating missing portion 2b and the surrounding coating 2c around it are heated. Since this heating is performed to evaporate and remove excess moisture absorbed by the peripheral coating 2c, the heating is performed from the coating 2 side at a temperature that does not cause water impingement. Specifically, a seal member 22 of an action unit 20 of the dehydration processing apparatus 10 to be described later is brought into contact with the coating 2 to cover the coating missing portion 2b and the peripheral coating 2c, which are heating sites, that is, sites to be dehydrated. And heated by irradiating infrared rays from the heating source 40, and ventilated by the ventilation means 30. At the time of the ventilation, in order to improve the dewatering efficiency, exhaust is performed such that the inside of the enclosure 21 is depressurized while warm air or hot air is passed through the enclosure 21.
[0023]
In the cleaning process (see FIG. 1 (d)), sanding or the like is performed, and the surface oxide film of the base material 1 and the modified layer on the surface of the peripheral coating 2c in the coating missing portion 2b are removed. The peripheral coating 2c is cleaned in an annular region having a width of about 50 mm.
Each process so far, that is, the refining process, the dehydrating process, and the cleaning process are pre-processing, and are performed in a state where no covering material is attached to the covering missing portion 2b. Then, if it is confirmed that there is no defect such as swelling in the peripheral coating 2c, the next main processing is performed.
[0024]
The covering layer forming operation (see FIG. 1 (e)) is performed by attaching a covering material to the covering missing portion 2b. That is, the covering missing portion 2b and the peripheral covering 2c are covered with the repair covering material 3, and the base material 1 is heated from the back surface (the lower surface in the drawing) of the base material 1. The covering material 3 may be the same as the covering 2, a partly modified one, or a different one, and may be any covering resin that is fused or bonded to the covering 2. The form may be a powder (see, for example, Patent Documents 1, 3, and 4) or a powder resin molded sheet (see, for example, Patent Document 2). As long as the covering material 3 can be attached in close contact, a lining tool 4 (see, for example, Patent Documents 1 to 4) such as a pressing device, a spraying device, and a supply / discharge device may or may not be used.
[0025]
As the heating device 5 for heating the base material 1, an induction heating device is easy to use. However, if the base material 1 can be heated to the melting point in order to fuse the coating 2 and the coating material 3, other devices and heating methods can be used. For example, flame heating or heat transfer heating from a heating wire may be used.
Thus, in this resin coating repair method, a new resin coating is formed which covers the coating missing portion 2b and overlaps the peripheral coating 2c.
In addition, when the coating material 3 is a reaction curable resin such as an epoxy resin, particularly when the coating layer is formed using a liquid paint, heating that causes the sudden boiling of the water during the construction is not often performed. Even in such a case, by performing the pretreatment including the dehydration treatment, a strong adhesive force equivalent to that of the new coating can be stably exhibited even in the repair.
[0026]
Further, in the above-described repair method, heating is performed while surrounding the covering missing portion 2b and the peripheral covering 2c in the repair target area during the dehydration process, but the dehydration process may be performed with the repair target area open. For example, the region to be repaired may be heated by supporting the heating source 40 with a pole or an arm. Further, the ventilation may be performed by blowing air using a fan, or warm air may be blown using a dryer or the like.
[0027]
In the above repair method, heating is performed only from the coating side during the dehydration process, and heating is performed only from the back side of the base material during the coating layer forming operation (the heating means in each step is a more suitable method for this method). Centralization makes it easy to control the temperature for each process, etc., or for time-consuming dehydration processing, multiple units of inexpensive devices with an infrared source are applied in parallel to multiple repair locations. In addition, it may be heated only from the coating side during the dehydration process or during the coating layer forming operation, or only from the back side of the base material during the dehydrating process or during the coating layer forming operation. You may make it heat (these systems have the advantage that only one heating means is required). Even with only heat input from the back surface of the base material, the coating is heated by heat transfer. Alternatively, heating may be performed from both the coating side and the base material back side during dehydration processing, and heating may be performed only from the base material back side during coating layer forming operation, and heating may be performed only from the coating side during dehydration processing. Sometimes it may be heated from both the coating side and the back side of the base material, or it may be heated from both the coating side and the back side of the base material during the dehydration process and the coating layer forming operation (covering Heating from both the side and the back side of the base material shortens the time required for dehydration and coating layer formation operations).
[0028]
The dehydration processing apparatus 10 shown in FIG. 2 will be described in detail. 2A is a perspective view of the entire dehydration apparatus 10, FIG. 2B is a perspective view of the action part 20 as viewed from obliquely below, FIG. 2C is a front view of the action part 20, and FIG. 20 is a longitudinal end view of FIG.
[0029]
The dehydrating apparatus 10 includes an action unit 20 mainly composed of an enclosure 21, a ventilation means 30 connected in communication with flexible piping, a heating source 40, and a power supply unit 41 connected to the power supply line. A heating means, and a controller 50 connected to the power supply unit 41 and the radiation thermometer 51 by a signal cable are provided. Among them, the heating source 40 and the radiation thermometer 51 are built in the enclosure 21 and attached to the inner bottom of the enclosure 21 (the ceiling in the illustrated posture). The ventilation means 30, the power supply unit 41, and the controller 50 can be set apart from the action unit 20.
[0030]
The enclosure 21 is made of a plate of, for example, a phenol resin (for example, bakelite) that is strong and excellent in heat resistance and airtightness, and is formed in a substantially rectangular parallelepiped shape, but one side thereof is opened to form an opening 23. Yes. A seal member 22 is attached to the end (lower end in the figure) of the enclosure 21 formed by the edge of the opening 23 so that the inside of the enclosure 21 is brought into contact with the object to be repaired. The space can be made airtight. Although not shown and omitted, the enclosure 21 is appropriately provided with an eyebolt for transportation, a handle, a protrusion for attaching a fixing jig, and the like.
[0031]
The ventilation means 30 includes a throttle valve 31, a heater 32 (intake heating means), and an air supply pipe 33. The air supply means 30 includes an air supply means for introducing air into the enclosure 21 from the outside, an exhaust pipe 34, and a blower 35. It is roughly divided into exhaust means for exhausting air from inside the body 21 to the outside. The amount of ventilation and the degree of pressure reduction are set and adjusted according to the degree of throttling at the throttle valve 31 and the operating state of the blower 35, and the air sent into the enclosure 21 by the amount of ventilation and the amount of current supplied to the heater 32. The temperature is set and adjusted. However, such a configuration is merely an example, and the blower 35 may be disposed on the air supply side instead of the exhaust side, or may be disposed on both the air supply and exhaust sides. A vacuum cleaner can also be used as the blower 35.
[0032]
As the heating source 40, an infrared lamp or a far-infrared lamp is easy to use, but any other heat source may be used as long as it can irradiate light including infrared rays from the opening 23. A plurality are arranged.
The power supply unit 41 adjusts the heating state by intermittently supplying power to the heating source 40 or by adjusting the power supply amount according to the control of the controller 50.
A radiation thermometer 51 is also provided on the inner bottom of the enclosure 21, but is installed near the corner so as to measure the surface temperature of the peripheral coating 2 c instead of the coating missing portion 2 b. The measured value (temperature Tc) is sent to the controller 50 as needed.
[0033]
The controller 50 includes a programmable computer, a sequencer, and the like, monitors the temperature Tc, and controls the operation of the heating source 40 so that it becomes a target value. The control method is not limited to fixed value control, and may be follow-up control with variable target value, simple proportional control, or more complicated PID control or optimal control. The temperature Tc is also displayed on the screen as a numerical value or a graph.
[0034]
Such a dehydrating apparatus 10 is used in the dehydrating process as described above (see FIG. 1C), and in this case, the seal member 22 of the action unit 20 surrounds the coating missing part 2b and the peripheral coating 2c. While being in close contact with the surface of the coating 2, the ventilation state of the ventilation means 30 is adjusted, and the operation of the heating source 40 is controlled by the controller 50.
For example, when the inner space of the enclosure 21 is about 100 L and the coating 2 is a polyethylene having a melting point of 125 ° C., the air flow rate is about 0.1 L / s, the air blowing temperature is about 20 ° C., and the pressure reducing allowance is about 0.01 MPa. The temperature Tc is set to 125 ° C. ± 2 ° C. (that is, about 0.09 MPa which is slightly lower than atmospheric pressure≈0.1 MPa).
This state is maintained over a necessary time known in preliminary experiments or the like, for example, for 4 hours, so that the peripheral coating 2c is sufficiently dehydrated.
[0035]
The dehydrating apparatus 60 will be described with reference to FIG. 3 (a) showing a longitudinal end view of a repaired part and an action part and a block diagram of a controller and the like.
[0036]
The dehydrating apparatus 60 is different from the dehydrating apparatus 10 described above in that a thermocouple 61 is added as a base material back surface temperature detecting means and an estimation calculating routine is added as an interface temperature calculating means. .
In order to measure the temperature of the base material back surface 1b, the thermocouple 61 employs a material that can be attached to and detached from the base material back surface 1b or is attached to the base material back surface 1b with an appropriate jig. To send to.
[0037]
The estimation calculation routine is a program additionally installed in the controller 50, whereby the controller 50 uses the temperature Tb measured by the thermocouple 61 and the temperature Tc measured by the radiation thermometer 51 to determine the peripheral coating 2 c and the base material 1. The estimated temperature Ta of the boundary surface is calculated. When the material and thickness of the base material 1 and the material and thickness of the covering 2 are input on the menu selection screen, parameter setting screen, etc., the heat transfer coefficients Kb and Kc are obtained from a database or the like, and an appropriate calculation using them is performed. The temperature Ta is calculated using an equation, for example, a proportional proration method [Tb + (Tc−Tb) × Kc / (Kb + Kc)]. The controller 50 is partially modified so that the temperature control routine causes the temperature Ta to follow the target value. Furthermore, the control target has been modified so that it can be set by a graph in which time is plotted on the horizontal axis and temperature is plotted on the vertical axis (see FIGS. 3B to 3D).
[0038]
When such a dehydration apparatus 60 is used in the dehydration process, the temperature Ta can be finely controlled, and the peripheral coating 2c can be sufficiently dehydrated while reliably avoiding the sudden boiling of water.
For example (see FIG. 3 (b)), the temperature Ta can first be maintained at a constant temperature slightly lower than the boiling point of water for a certain period of time, and then maintained at a temperature slightly lower than the melting point of the coating 2, so By doing so, appropriate dehydration is performed with high accuracy.
[0039]
Moreover, in order to reduce the adverse effect of the estimation error of the temperature Ta (see FIG. 3C), the temperature Ta in the vicinity of the boiling point is a temperature slightly lower than the boiling point, a temperature equal to the boiling point, and a temperature slightly higher than the boiling point. It can also be changed in three stages.
Furthermore, the rise of the temperature Ta up to the vicinity of the boiling point can be made gentle in order to avoid overheating of the tapered section of the peripheral coating 2c (see FIG. 3D).
[0040]
The dehydration processing apparatus 70 shown in FIG. 4 will be described. 4A and 4B show the configuration, in which FIG. 4A is a longitudinal sectional end view of the repair site and the action unit 20 and a block diagram of the controller 50 and the like, and FIG. 4B is a schematic flowchart of processing of the controller 50.
[0041]
The dehydrating apparatus 70 is different from the dehydrating apparatus 10 described above in that a capacity sensor 71 and a moisture content measuring device 72 are added as moisture content detecting means, and the controller 50 stops the dehydrated state determining means and the dehydrating process. The program was modified to function as a means.
When the capacitance sensor 71 and the moisture content measuring device 72 are attached to the peripheral coating 2c and the moisture content measuring device 72 is operated based on the fact that the dielectric constant of the peripheral coating 2c changes according to the moisture content, The capacitance is measured as a rate-corresponding physical quantity, a predetermined calculation is performed to determine the moisture content W, and this is sent to the controller 50 as a detection result as needed.
[0042]
In addition to performing the above-described temperature control as the dehydration process, the controller 50 (see FIG. 4 (b)), in parallel with that, the dewatering state of the peripheral coating 2c is suitable for the coating layer forming operation based on the moisture content W. Is determined (steps S1 and S2), and the dehydration process is stopped based on the determination result (steps S3 to S5).
Specifically, the moisture content W is input from the moisture content measuring device 72 (step S1), and it is checked whether or not this is smaller than a predetermined threshold value α (step S2). While the moisture content W is greater than or equal to the threshold value α (No in step S2), the moisture content W check is repeated (steps S1 and S2).
[0043]
When the moisture content W falls below the threshold value α (Yes in Step S2), a waiting time is set (Step S3), and the dehydration process is stopped (Step S5) after waiting for the time to elapse (Step S4). ). The dehydration process may be stopped by instructing the control routine to stop the power supply from the power supply unit 41 to the heating source 40, and prompting the operator to perform a stop operation by providing a screen display and audio guidance indicating that the dehydration has been performed. But it ’s okay. The waiting time is for surely eliminating insufficient dehydration due to a measurement error of the moisture content W or the like, and is set to zero when unnecessary. Further, the threshold value α is set based on the material of the covering 2 and the like, and is set to about 0.03 mass% for polyethylene, for example.
[0044]
By using such a dehydration apparatus 70 in the dehydration process, the dewatering state of the peripheral coating 2c is accurately grasped in real time, and on the basis of this, after confirming the sufficient dewatering state when the peripheral coating 2c is dehydrated. The dehydration process is stopped. Therefore, the extra dehydration process is rounded up, and the dehydration process is shortened accordingly. Moreover, there is no worry of insufficient dehydration.
[0045]
The dehydration processing apparatus shown in FIG. 5 will be described. 5A and 5B show the structure of the adapter 80. FIG. 5A is a perspective view of the action portion 20 as viewed from obliquely above, FIG. 5B is a perspective view of the action portion 20 as viewed from obliquely below, and FIG. (D) is a front view of the adapter 80, (e) is a side view of the adapter 80, (f) is a side view of another adapter 91, and (g) is a side view of the other adapter 91. .
[0046]
This action part 20 is different from that described above in that the enclosure 21 has been modified from a square shape into a cylindrical shape and an adapter 80 that is attached to and detached from the enclosure 21 is added. Adapters 90 and 91 are also added.
The enclosure 21 (see FIGS. 5A and 5B) is a cylindrical body that is closed at one end and opened at the other end, and an opening 23 for infrared irradiation is formed at the open end 21a. A ring 83 that goes around the outer peripheral surface of the enclosure 21 is attached in the vicinity of the open end 21a.
[0047]
The adapter 80 (see FIGS. 5 (c) to 5 (e)) is a short cylinder with both ends open, and the upper end 81 (the other end) remains cut off flat, but the lower end (one end) is curved and cut off. It is in the shape of a heel edge, and a seal member 22 is attached here. A hook 82 is also attached to the outer peripheral surface of the adapter 80. The inner diameter of the adapter 80 is formed to be slightly larger than the outer diameter of the enclosure 21. Therefore, when the open end 21 a is inserted into the upper end 81 and the hook 82 is hung on the ring 83, the adapter 80 is attached to the action portion 20. Thus, the upper end 81 is connected to the opening 23. Conversely, the adapter 80 can be removed from the enclosure 21 by removing the hook 82 from the ring 83.
[0048]
The adapters 90 and 91 are also the same as the adapter 80, but are slightly different in the curved state (the shape of the edge of the heel) of the seal member 22 mounting end. Specifically, the adapter 80 is gently curved to fit the outer peripheral surface of the large-diameter tube, and the adapter 90 is strongly curved to fit the outer peripheral surface of the small-diameter tube. The lower end of the adapter 91 is in the shape of a ridge that fits the inner surface of the tube.
[0049]
The usage mode of such a dehydration apparatus will be described with reference to the perspective view of FIG. In this case, a plurality of adapters 80, 90, 91 that can be attached to and detached from the enclosure 21 used in the dehydration process are adapted to the pipe diameter of the base material 1 to be repaired, for example, the adapter 80. This is selected and attached to the enclosure 21. Then, the seal member 22 is brought into close contact with the repair site of the base material 1. At this time, if the piping is in the way, the direction of the piping may be changed by loosening the hook 82 and rotating the enclosure 21 about the axis. Thereafter, the dehydration process is performed in the same manner as described above.
[0050]
When repairing the outer peripheral surface of another pipe having a different diameter, the adapter 80 is removed from the action portion 20 and, for example, the adapter 90 is attached. When repairing the inner peripheral surface of the pipe, for example, an adapter 91 is attached to the action portion 20.
Thus, the resin-coated dewatering apparatus is convenient and economical because the same apparatus can be used not only for flat plates but also for pipes of various diameters by changing adapters.
[0051]
The dehydration processing apparatus 100 shown in FIG. 6 will be described. 6A and 6B show the structure and method of use, in which FIG. 6A is a perspective view of the entire apparatus, and FIG. 6B is a longitudinal end view of a repair site and an action part.
This dehydration apparatus 100 is most different from the dehydration apparatus 10 described above in that the heating source 40 is removed from the action unit 20.
Accordingly, the tip of the air supply pipe 33 enters the inside of the enclosure 21 or a tube corresponding to an extension member of the air supply pipe 33 in order to blow hot air and hot air on the covering missing part 2b and the peripheral covering 2c accurately. A shaped member is added to the inside of the enclosure 21, and the outlet is directed to the center of the opening 23.
[0052]
The temperature management by the controller 50 is performed by variably controlling the amount of heat generated by the heater 32. Further, the blower 35 moves to the place where the throttle valve 31 is located, that is, to the air supply pipe 33 side and blows air. An exhaust tower 36 is connected to the exhaust pipe 34 in place of the blower 35. The exhaust tower 36 has a chimney-like shape and discharges the exhaust to the sky. However, the exhaust tower 36 is unnecessary in a situation where the hot air or hot air may be discharged directly from the action unit 20. Since the inside of the enclosure 21 is not depressurized, and some air leakage does not become a problem, the seal member 22 is also omitted.
[0053]
When such a dehydrating apparatus 100 is used in the dehydrating process, warm air and hot air are blown from the air supply pipe 33 to the covering missing portion 2b and the peripheral covering 2c, and the repaired portion is dehydrated by the warm air and hot air. Since there is no heating by infrared irradiation or the like, the aeration temperature is increased to shorten the processing time. Since the exhaust gas is discharged toward the sky by the exhaust tower 36, the action unit 20 of the present apparatus can be used in the pipe. The decompression in the enclosure 21 is eliminated, and accordingly, the negative pressure suction force does not work at the opening 23, and the action portion 20 is not adsorbed to the repair site. Fixing the action part 20 by stretching a jig, fixing the action part 20 with a fastener such as a wire when using it on the outer surface of the pipe, and fixing the action part 20 with eg heavy stone when using it on a flat plate Good.
[0054]
In addition, the dehydration processing apparatus 100 also includes a thermocouple 61 as a base material back surface temperature detection means and an estimation calculation routine as an interface temperature calculation means in order to reliably avoid bumping like the dehydration processing apparatus 60. Fine temperature control may be performed.
In addition, like the dehydration apparatus 70, in order to shorten the dehydration process, a capacity sensor 71 as a moisture content detection unit, a moisture content measuring device 72, a dehydration state determination unit, and a program functioning as a dehydration process stop unit are added. The dewatering state of the peripheral coating 2c may be grasped in real time.
Furthermore, the enclosure 21 may be modified so as to be detachable from the adapters 80, 90, 91, etc., as in the dehydrating apparatus of FIG. 5, so that it can be used for repairing pipes of various diameters.
[0055]
【Example】
In order to confirm the effectiveness of performing the dehydration process prior to the coating layer forming operation, a water-containing test piece was prepared, the dehydration apparatus 10 was applied to the coating 2, and the appearance after the dehydration process was examined.
The test piece is made of a steel plate of 150 mm × 90 mm × 9 mm as a base material 1, coated with polyethylene having a melting point of 125 ° C. to form a coating 2 having a thickness of 2 mm, and then immersed in a 50 ° C. seawater tank. is there. The soaking period is about 6 months.
[0056]
In the dehydration apparatus 10, the opening 23 is 500 mm × 500 mm, and four 300 W infrared lamps are employed as the heating source 40. These lamps are installed at a distance of about 100 mm to 200 mm, for example 150 mm, from the coating 2 to heat the inside of the opening 23 substantially uniformly. When ventilating with the ventilation means 30, dry air at about 20 ° C. was supplied at a flow rate of about 0.1 L / s, and when the pressure was reduced, the pressure was reduced from atmospheric pressure to about 0.01 MPa.
[0057]
And even if the moisture on the surface of the coating 2 was wiped off, when the coating layer forming operation was carried out without the dehydration process, many blisters occurred under the coating 2, and the appearance defect was obvious. In addition, even when the dehydration treatment is performed, when the coating surface temperature is maintained at 130 ° C. exceeding the melting point 125 ° C. of the coating 2 for 0.5 hour, unevenness appears on the surface of the coating 2 and the coating 2 deteriorates. The coating layer forming operation was not performed.
On the other hand, when the dehydration process was performed to keep the surface temperature of the coating 2 at a melting point of 125 ° C. or lower, the coating layer formation operation was performed because there was no abnormality in the dehydration process. Depending on conditions such as holding time, there may be a case where a defect occurs in the coating layer forming operation and a case where it does not occur.
[0058]
Specifically, when the surface temperature of the coating 2 was maintained at 115 ° C. for 5 hours by dehydration, swelling occurred under the coating 2 in a subsequent coating layer forming operation, and an appearance defect was found. This appears to be insufficient dehydration.
Even when the surface temperature of the coating 2 is kept at the same 115 ° C., if it is kept for 10 hours, the swelling generated under the coating 2 in the coating layer forming operation is reduced and the degree of malfunction is reduced, but the dehydration is still insufficient. It is seen.
When the time during which the surface temperature of the coating 2 is maintained at 115 ° C. for the dehydration process is longer than 24 hours, good repair results are obtained, and it is considered that the surface has been sufficiently dehydrated.
[0059]
Further, when the surface temperature of the coating 2 was kept at 120 ° C. for 5 hours by dehydration, a slight swelling occurred under the coating 2 in the subsequent coating layer forming operation, resulting in poor appearance. This is also seen as insufficient dehydration.
Even in the dehydration treatment in which the surface temperature of the coating 2 is kept at the same 120 ° C., when it is held for 10 hours, a good repair result is obtained, and it is considered that the film has been sufficiently dehydrated.
[0060]
Furthermore, when the surface temperature of the coating 2 was maintained at 125 ° C. for only 4 hours by dehydration, a slight swelling occurred under the coating 2 during the coating layer forming operation, resulting in poor appearance. However, when the surface temperature of the coating 2 is maintained at 125 ° C. for 5 hours by dehydration, good repair results are obtained and it is considered that the surface has been sufficiently dehydrated.
Even in the dehydration process in which the surface temperature of the coating 2 is kept at the same 125 ° C., the dewatering process is sufficient for 4 hours when using air blowing and 3.5 hours when using decompression together. It was.
[0061]
[Others]
For direct heat input to the base material, in addition to high heat input heating means such as induction heating and gas heating, a heating method of irradiating infrared rays is also useful. The former large heat input heating has the advantage that the heating can be carried out efficiently, whereas the latter infrared irradiation heating has the advantage that it can be carried out easily using a relatively simple device with excellent controllability. is there. Both can be used together. For example, when infrared heating and induction heating are used together for heating the resin coating, heat is input from both the front and back surfaces, so the heat transfer time is from 1/4 (transition period) to 1/2 (one-sided heating). (Stationary phase). As a result, a resin coating that hardly conducts heat can enjoy a great merit. Also, different or similar devices may be installed in parallel and operated simultaneously or alternately.
[0062]
Specific examples of the infrared source include a far-infrared source that is difficult to detect a visible light component that has been frequently used in recent years, a red-light heater mixed with visible light, a red light bulb, and an incandescent light bulb.
As a paint having a high infrared absorption rate, a paint containing carbon is easy to use. Since the metal base material generally has an infrared absorption rate of only a few percent, it is difficult to use the infrared irradiation heating as it is, but the infrared irradiation heating can be efficiently performed by black coating with the above-mentioned paint. The resin coating generally has a high infrared absorptivity of several tens of percent, so that it is suitable as it is for infrared irradiation heating.
[0063]
【The invention's effect】
As is apparent from the above description, in the resin coating repair method of the present invention, the dehydration process is preceded by the coating layer forming operation, so that appropriate repair can be performed again and reliably.
Also, in the dehydration process, heating is performed from the coating side, and in the coating layer forming operation, heating is performed from the base material side. In addition, when the aeration is performed, warm air or hot air is also ventilated, so that dehydration of the repaired portion can be efficiently performed.
[0064]
In the resin-coated dehydration processing apparatus of the present invention, the heating source and the air supply / exhaust means are combined with the enclosure so that not only dehydration by local heating but also water vapor removal by ventilation is performed. The dehydration process preceding the coating layer forming operation is efficiently performed, which helps to perform an accurate resin coating repair method.
Further, in another resin-coated dewatering apparatus of the present invention, the dewatering efficiency is further improved by supplying warm air and hot air when ventilating the enclosure. Furthermore, in another resin-coated dehydration apparatus of the present invention, the dehydration target part is heated by the warm air / hot air supplied to the enclosure, so that the dehydration preceding the coating layer forming operation is performed. The treatment is performed efficiently and helps to execute an accurate resin coating repair method.
[0065]
Further, in the dehydration processing apparatus that estimates the boundary surface temperature and keeps it below the boiling point, overheating under the coating is reliably avoided, and the dehydration processing preceding the coating layer forming operation is efficient and It is done accurately. Further, in the dehydration processing apparatus that detects the water content and discriminates the dehydrated state, the wasteful dehydration process is omitted, and the dehydration process preceding the coating layer forming operation is performed very efficiently. Moreover, in the dehydration processing apparatus provided with the detachable adapter, it can be shared with the cladding tubes having different diameters, and the dehydration processing prior to the coating layer forming operation can be performed efficiently and easily.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a longitudinal end view of a repaired part of a resin coating repair method according to the present invention.
2A is a perspective view of the entire apparatus, FIG. 2B is a perspective view of the working portion viewed obliquely from below, and FIG. 2C is a front view of the working portion. (D) is a vertical end view of the action portion.
3A is a longitudinal sectional end view of a repaired part and an action part, a block diagram of a controller, etc., and FIGS. 3B to 3D are graphs showing temperature changes. FIG. is there.
4A is a longitudinal sectional end view of a repaired part and an action part, a block diagram of a controller, etc., and FIG. 4B is a schematic flowchart of a process of the controller in the resin-coated dewatering apparatus of the present invention.
5A is a perspective view in which the working part is looked down obliquely from above, FIG. 5B is a perspective view in which the working part is looked up obliquely from below, and FIG. (D) is a front view of the adapter, (e) is a side view of the adapter, (f) is a side view of another adapter, (g) is a side view of the other adapter, (h) ) Is a perspective view of the adapter in use.
6A is a perspective view of the entire apparatus, and FIG. 6B is a longitudinal end view of a repaired part and an action part of the resin-coated dewatering apparatus of the present invention.
[Explanation of symbols]
1 Base material (steel plate, steel pipe, object of resin coating)
1a Boundary surface (joint surface, coating bottom surface, base material surface)
1b Base material back
2 Coating (thermoplastic resin layer, anticorrosion coating layer, resin coating)
2a Covered damaged part (repair required part)
2b Cover missing part (repair target part, heated part)
2c Peripheral coating (around coating missing part, heated part, dehydration target part)
3 Coating materials (sheet resin, powder resin, thermoplastic resin)
4 Lining tools (spraying device, pressing device, supply / discharge device)
5 Heating device (Induction heating, flame heating, heat transfer heating, fusion heating means)
10 Dehydration processing equipment (Resin coating dehydration processing equipment)
20 Action part (installation part to repair target part)
21 Enclosure (Box, shell, cylinder, member enclosing the repair target part)
22 Sealing member (contact end airtight means)
23 Opening (Infrared irradiation port)
30 Ventilation means (air supply means, exhaust means, decompression means, hot air / hot air supply means)
31 Throttle valve (supplying means, pressure reducing means)
32 Heater (air supply means, air supply heating means)
33 Air supply pipe (pipe for air supply, air supply means)
34 Exhaust pipe (decompression pipe, exhaust means)
35 Blower (exhaust means, decompression means)
40 Heating source (infrared lamp, infrared emitting means)
41 Power supply unit (heating adjustment part)
50 controller (calculation means, discrimination means, control means)
51 Radiation thermometer (Coating surface temperature detection means)
60 Dewatering equipment (resin dewatering equipment)
61 Thermocouple (base material back surface temperature detection means)
70 Dewatering equipment (resin-coated dewatering equipment)
71 Capacitance sensor (moisture content corresponding physical quantity measuring means, moisture content detecting means)
72 Moisture content measuring device (physical quantity conversion unit, moisture content detection means)
80 Adapter (cylinder)
81 Upper end (the other end connected to the opening of the enclosure)
82 Hook (detaching means between the enclosure and adapter)
83 Ring (detachment means between enclosure and adapter)
90 Adapter (cylinder)

Claims

A coating that spreads the resin material in layers when re-forming the resin coating in the area to be repaired so that this coating missing portion is included in order to repair the missing coating portion occurring in the member having the resin coating. Prior to the layer forming operation, the existing resin coating in the region to be repaired is subjected to a dehydration process in which the existing resin coating is heated to expel moisture in the coating, and the coating surface of the existing resin coating Detecting the temperature, the coating surface temperature is set over the holding time sufficient to dehydrate the water content of the existing resin coating to a water content of less than 0.1 mass %, which can avoid bumping of the water. A method of repairing a resin coating, characterized in that the dehydration treatment is performed by maintaining the heated state below the melting point of the existing resin coating.

When performing the dehydration process, based on an enclosure in which an opening is formed, a heat source stored in the enclosure, a coating surface temperature detection unit attached to the enclosure, and a detection temperature of the coating surface temperature detection unit Using a dehydration apparatus having a surface temperature control means for controlling the operation of the heating source, surrounding the repair target area with the enclosure by bringing the opening side into contact with the member to be repaired, The coating surface temperature is detected by the coating surface temperature detection means, and the coating surface temperature is kept below the melting point of the existing resin coating for a holding time sufficient to sufficiently dehydrate the water content of the existing resin coating. The method for repairing a resin coating according to claim 1, wherein the control is performed by the surface temperature control means.

A heating condition for holding the coating surface temperature at 115 ° C. for 24 hours or more, a heating condition for holding the coating surface temperature at 120 ° C. for 10 hours or more, and a heating condition for holding the coating surface temperature at 125 ° C. for 5 hours or more. 3. The method of repairing a resin coating according to claim 1, wherein the dehydration treatment is performed on the member for which the existing resin coating is polyethylene under a heating condition.

The dehydration treatment is performed on the member whose repair is made of polyethylene for the existing resin coating under heating conditions in which the surface temperature of the coating is maintained at 125 ° C. for 4 hours or more while ventilating the heating site. The method for repairing a resin coating according to claim 1 or 2.

In performing the dehydration treatment, in addition to maintaining the coating surface temperature below the melting point of the existing resin coating, the base material back surface temperature is set for the back surface of the base material constituting the base of the resin coating. Detect and calculate the estimated temperature of the boundary surface between the existing resin coating and the base material based on the base material back surface temperature and the coating surface temperature, and adjust the heating so that the estimated temperature is kept below the boiling point of water The method for repairing a resin coating according to claim 1, wherein:

The dehydration processing apparatus detects a base material back surface temperature for the back surface of the base material constituting the base of the resin coating, and the base material back surface temperature and the coating surface temperature. Interface temperature calculation means for calculating an estimated temperature of the boundary surface between the existing resin coating and the base material based on the above, and an interface temperature control for controlling the operation of the heating source so as to keep the estimated temperature below the boiling point of water Means for controlling the temperature of the boundary surface with the interface temperature control means while performing the control for the coating surface temperature with the surface temperature control means when performing the dehydration process. The method for repairing a resin coating according to claim 2, wherein the repair is performed.

6. The method for repairing a resin coating according to claim 1 or 5, wherein the dehydration treatment is performed while the pressure is reduced around the heating site.

The dehydration apparatus includes an air supply unit that supplies air to the enclosure, and an exhaust unit that exhausts air from the enclosure, and the exhaust unit performs the dehydration process. The method of repairing a resin coating according to claim 2 or 6, wherein the air supply means ventilates the enclosure while decompressing the enclosure.

The dehydration treatment is performed on the member whose repair is made of polyethylene for the existing resin coating under heating conditions in which the coating surface temperature is maintained at 125 ° C for 3.5 hours or more. 8. The method for repairing a resin coating according to 8.

Prior to the dehydration treatment, the cylinder is detachably attached to the enclosure, and one end is formed in the shape of a heel and the other end is an adapter connected to the opening when mounted on the enclosure. The outer shape of the target is fitted to the dehydration apparatus with the one end adapted to the outer shape, and then the one end of the adapter is brought into contact with the member to be repaired, thereby opening the opening side of the enclosure. The method of repairing a resin coating according to any one of claims 2, 6, and 8, wherein the dehydration process is performed by contacting the member.

Heat for re-forming the resin coating in the repair target area is a method of directly applying heat to the coating by irradiating the coating surface with infrared rays, and directly applying heat to the base material constituting the base of the coating. The method for repairing a resin coating according to any one of claims 1 to 10, wherein a method of transferring heat to the coating on the material is knitted.

The resin coating according to claim 11, wherein in the dehydration treatment, heating is performed by a technique of irradiating the coated surface with infrared rays, and in the coating layer forming operation, heating is performed by a technique of directly inputting heat to a base material. Repair method.

Heat for re-forming the resin coating on the repair target region is directly applied to the base material constituting the base of the coating over both steps of the dehydration process and the coating layer forming operation, and this heat is applied to the base material. The method for repairing a resin coating according to claim 1, wherein the method is performed by a method of transferring heat to the coating of the resin.

The method for repairing a resin coating according to any one of claims 11 to 13, wherein the means for directly inputting heat into the base material is high heat input heating means such as induction heating.

The means for directly inputting heat into the base material is a heating method in which a paint having an infrared absorption rate higher than that of the base material is applied and irradiated with infrared light. Repair method of resin coating as described in 4.