JP3592877B2

JP3592877B2 - Spraying method for irregular refractories

Info

Publication number: JP3592877B2
Application number: JP03070597A
Authority: JP
Inventors: 泰史小野; 煌江上; 克美野中; 晃中田
Original assignee: AGC Ceramics Co Ltd
Current assignee: AGC Ceramics Co Ltd
Priority date: 1997-02-14
Filing date: 1997-02-14
Publication date: 2004-11-24
Anticipated expiration: 2017-02-14
Also published as: JPH10227576A

Description

【０００１】
【発明の属する技術分野】
本発明は、強度と嵩比重が大きい不定形耐火物を施工する不定形耐火物の吹付施工方法に関する。
【０００２】
【従来の技術】
不定形耐火物の吹付施工では、型枠を必要とする流し込みによる施工方法に比べて、施工作業を省力化できるという利点があり、このため、従来から不定形耐火物の吹付施工方法が実施されている。
【０００３】
従来の吹付施工方法は、いわゆる乾式の吹付であり、流動性のない乾いた不定形耐火物用粉体組成物を、圧縮空気をキャリアーとして、配管もしくはゴムホースで施工現場に搬送し、吹付ノズルで不定形耐火物が必要とする水分を注入して吹付ノズルから吹付施工している。
【０００４】
しかし、このような方法では、不定形耐火物用粉体組成物の坏土中の細かい、例えば０．１ｍｍ以下の耐火性粉末の粒子の分散状態と濡れが不充分な状態で吹付施工されるため、吹付施工された不定形耐火物の坏土中には多くの空気が取り込まれ、その結果、吹付施工された不定形耐火物の施工体は流し込み施工によるものと比べて気孔率が大きくかつ嵩比重が小さくなるため、耐食性などの耐火物性能が劣るものであった。
【０００５】
一方、上記乾式の吹付施工用の不定形耐火物用粉体組成物に、本来吹付ノズルで添加する必要量の水分を予め添加混練したのち、圧縮空気をキャリアーとして配管もしくはゴムホースで施工現場に空気搬送し、吹付ノズルで吹き付ける湿式吹付施工することも知られているが、この乾式の吹付施工用の不定形耐火物用粉体組成物に水を加えて混練したものは、吹き付け後のダレを防止するために、坏土の粘性を増加する粘土等の成分や、アルミナセメントの硬化時間を早めることで粘性を急激に増加する成分などを含むことが必須であって、その結果坏土の粘性が大きくなりすぎて、空気搬送時に脈動が発生したり、著しくは配管内で閉塞を起こしたりする等の問題を有していた。
【０００６】
また、これらを回避する手段として、特願平８−１１６６２１号に記載の不定形耐火物の吹付施工方法が提案されており、この方法はそれなりに有用な方法であるが下記の問題を有していた。
【０００７】
すなわち、不定形耐火物用粉体組成物に水を加えて混練した自己流動性を有する坏土を圧送ポンプによって吹付ノズルに送り、吹付ノズルの手前に設けた圧縮空気注入口および急結剤注入口からそれぞれ圧縮空気と急結剤を注入して吹付施工するものであるが、圧縮空気の注入量を過度に多くすると、不定形耐火物用粉体組成物の混練した坏土に含まれる必須成分である耐火性骨材が分離して吹付ノズルで飛散するなどの問題点を有していた。
【０００８】
【発明が解決しようとする課題】
本発明の目的は、従来技術が有していた前述の課題を解決し、施工に際して一層の省力化が可能で、周囲への粉塵の飛散が少なく、施工体の気孔率が小さくかつ嵩比重が大きく、耐火物としての特性に優れた不定形耐火物の吹付施工方法を提供することにある。
【０００９】
【問題を解決するための手段】
上記目的を達成するために、本発明の不定形耐火物の吹付施工方法は、耐火性骨材、アルミナ及び／又はヒュームドシリカからなる平均粒径１０μｍ以下の耐火性超微粉を含む耐火性粉末、並びに少量の分散剤を含む不定形耐火物用粉体組成物に水を加えて混練し、得られる混練坏土を、上端内径50mm，下端内径100mm，高さ150mmで上下端が開口した円錐台形状のコーン型に流し込んで充たした後、前記コーン型を上方に抜き取って60秒間静置したときの広がり直径が160mm以上となる自己流動性を有するようにせしめ、次いで該坏土を、該坏土の脱泡工程と定量供給工程を備えた空気搬送装置に高圧空気を吹き込むことにより、先端部に吹付ノズルを接続した輸送管内を通して空気搬送し、搬送された坏土中に、急結剤注入口より所要量の急結剤を注入して、前記吹付ノズルにより吹付施工することを特徴とする。
【００１０】
【発明の実施の形態】
本発明の吹付施工方法の主な特徴は、自己流動性を有する不定形耐火物の坏土を施工現場へ空気搬送する点である。この方法によれば、予め所要の水分が混合された不定形耐火物の坏土を空気搬送により施工現場へ送るので、予め所要の水分を混合し混練することによって坏土中の水の分布が均一になり、かつ十分脱泡することができる。また、空気搬送中に坏土中に空気が再混入することもなく吹付施工される。その結果として気孔率が小さく嵩比重の大きい不定形耐火物の施工体が得られる。
【００１１】
本発明の吹付施工方法では、輸送管の先端部に接続された吹付ノズルの付近で急結剤が注入されるので、吹付ノズルから吹き付けられる坏土は、注入された急結剤により急速に自己流動性が低下し、このため垂直な壁面や、天井の壁面に吹付施工しても坏土が壁面から流れ落ちたり脱落することもなく施工できる。
【００１２】
さらに、自己流動性を有する坏土を輸送管先端部で急結することが可能であるため、自己流動性を有する坏土として粘性の低い組成や硬化時間を十分に長く
（例えば、混練後２時間以上自己流動性を保持可能な程度）保持できる組成物を選定可能であり、従来の乾式の吹付施工用の不定形耐火物用粉体組成物に水を加えて混練したものの吹付施工方法で見られる空気搬送時の脈動や、配管内部での閉塞を解消でき、吹き付け後に健全な吹付施工体が得られるなどの優れた特徴を有する。
【００１３】
吹付ノズル付近で急結剤を注入する際、吹付ノズルに直接設けた急結剤注入口より注入しても構わないが、吹付ノズルと輸送管との間に１００ｍｍ以上、好ましくは２００ｍｍ以上のノズル配管を配設し、そのノズル配管又はノズル配管と輸送管との接続部に設けた急結剤注入口から急結剤を注入するようにすれば、吹付ノズルから吐き出すまでの間に坏土と急結剤を均一に混合することができ、その結果急結剤の添加量を減少することができるとともに、急結剤の偏りによる耐火性能の劣化を防止することができる。
【００１４】
本発明では、空気搬送は混練坏土の脱泡工程と定量供給工程を望ましくは備えていることを特徴とする。脱泡工程および定量供給工程のより好ましい態様としては、複数のポケットを有するローターを備えた空気搬送装置（吹付装置）において、ポケットへ坏土を自重で投入する導管を設け、この導管で坏土に振動を与えることにより混練中に坏土に混入された空気を著しく低減することができる。また、ある程度粘性の高い坏土でも加振することにより完全な供給を行い、長時間の使用においても空気搬送量の定量性を維持できる。
【００１５】
空気搬送においては、高圧空気をキャリアーとして坏土を搬送するが、坏土の供給速度が一定でないと坏土の搬送圧力損失が変動し、結果として空気流量も変動するため脈動が発生し、その結果吹付ノズル先端での坏土吐出量が変動するため、施工後の組織が不均一になる等の問題を起こすが、本発明の空気搬送は混練坏土の脱泡工程と定量供給工程を備えていることでこれらの問題を回避できるなどの優れた特徴を有する。
【００１６】
また、脱泡工程と定量供給工程後の空気搬送では、材料吐出口部に２００ｍｍ以上の輸送管直線部を有することで材料坏土の吐出抵抗を低減でき、また材料坏土が輸送管内に付着し、著しくは閉塞するなどの問題を回避することができるという優れた特徴を有する。
【００１７】
本発明の空気搬送では、配管もしくはゴムホースを用いて坏土の輸送を行い、通常吹付ノズルの手前は１０ｍ程度のゴムホースとして作業者が吹付ノズルを自在に操作して吹付施工を行うものであるが、作業者が持つゴムホース部分の内部は坏土が空気中に浮遊した状態にあるので非常に軽量であり、作業労力を軽減することができる。
【００１８】
本発明では、坏土の流動性をコーン型を用いて評価する。すなわち、概ね２０℃の温度下で、不定形耐火物用粉体組成物に約２０℃の水を加えて混練した直後の坏土を上端内径５０ｍｍ，下端内径１００ｍｍ，高さ１５０ｍｍで上下端が開口した円錐台形状のコーン型に混練直後の坏土を流し込んで満たし、コーン型を上方に抜き取って６０秒間静置したときの広がり直径（２方向の広がりを測定した平均値、以下フロー値という）で表示する。
【００１９】
坏土はフロー値が１５０ｍｍ以上あれば自己流動性を呈する。しかし、空気搬送を安定して行うためには、坏土のフロー値は１６０ｍｍ以上、さらには１８０ｍｍ以上とするのが好ましい。フロー値の大きい坏土を使用すれば、空気搬送の抵抗を軽減し、搬送する配管もしくはホースの直径を小さくすることができ、坏土の長距離輸送を実現できる。
【００２０】
本発明で使用する粉体組成物は、耐火性骨材，耐火性粉末および少量の分散剤を含むものである。耐火性粉末は耐火性骨材の隙間を埋めて耐火性骨材を結合する結合部を形成する。耐火性骨材としては、アルミナ，ボーキサイト，ダイアスポアー，ムライト，バン土頁岩，シャモット，ケイ石，パイロフィライト，シリマナイト，アンダリュサイト，クロム鉄鉱，スピネル，マグネシア，ジルコニア，ジルコン，クロミア，窒化ケイ素，窒化アルミニウム，炭化ケイ素，炭化ホウ素，黒鉛などの炭素，ホウ化チタンおよびホウ化ジルコニウムから選ばれる１種以上が好ましい。
【００２１】
耐火性粉末としては、アルミナセメント，アルミナ，チタニア，ボーキサイト，ダイアスポア，ムライト，バン土頁岩，シャモット，パイロフィライト，シリマナイト，アンダリュサイト，ケイ石，クロム鉄鉱，スピネル，マグネシア，ジルコニア，ジルコン，クロミア，窒化ケイ素，窒化アルミニウム，炭化ケイ素，炭化ホウ素，ホウ化チタン，ホウ化ジルコニウムおよびヒュームドシリカなどの無定形シリカから選ばれる１種以上であって、平均粒径が３０μｍ以下のものが好ましい。
【００２２】
これらの耐火性粉末の一部として、アルミナやヒュームドシリカなどの平均粒径が１０μｍ以下、好ましくは５μｍ以下の耐火性超微粉を使用すると、組成物の坏土に加える水の量を減らすことができ、かつ混練後の坏土に良好な自己流動性を付与できる。
【００２３】
耐火性粉末の一部としてアルミナセメントを使用すれば、アルミナセメントが不定形耐火物の結合剤として機能し、施工体は常温から高温までの広い範囲において強度を保持できる。
【００２４】
良好な自己流動性を坏土に付与するための手段として、使用する耐火性骨材および耐火性粉末の種類に合わせて選定した粉末の分散剤を粉体組成物に配合しておくのが好ましい。分散剤としては、ポリメタリン酸塩類，ポリカルボン酸塩類，ポリアクリル酸塩類およびβ−ナフタレンスルホン酸塩類から選ばれる１種以上が好ましく、粉体組成物の耐火性骨材と耐火性粉末の合量１００重量部に対して０．０２〜１重量部添加しておくのが好ましい。
【００２５】
不定形耐火物用粉体組成物に加える水分は、施工された不定形耐火物の気孔率を小さくして耐火物としての良好な特性を確保できるように、粉体組成物１００重量部に対して１５重量部以下、さらには１２重量部以下とするのが好ましい。坏土の水分が少なければ、坏土中に含まれる耐火性骨材が沈降して坏土が不均質化するのを抑制でき、気孔率が小さく均質な組織の不定形耐火物の施工体が得られる。
【００２６】
坏土に注入する急結剤としては、粉末又は液体のものが使用可能である。液体の急結剤を使用する場合は、過度に液体(通常水を使用する)を増加すると吹付後の施工体の緻密性を低下するので好ましくない。
【００２７】
粉末の急結剤の搬送には粉末の添加量を均一に制御可能な装置が好ましく使用でき、通常は圧縮空気をキャリアーとして急結剤を搬送する装置が使用される。
【００２８】
また、液体の急結剤も供給量を均一に制御可能な液体ポンプが好ましく、使用する急結剤の種類に応じて適宜選定が必要であるが、プランジャーポンプ，ダイヤフラムポンプなどが好適とされる。
【００２９】
粉体の急結剤としては、アルミン酸ナトリウム，アルミン酸カリウム，アルミン酸カルシウムなどのアルミン酸塩類、炭酸ナトリウム，炭酸カリウム，重炭酸ナトリウム，重炭酸カリウム等の炭酸塩、硫酸ナトリウム，硫酸カリウム，硫酸マグネシウムなどの硫酸塩、ＣａＯ・Ａｌ_２Ｏ_３，１２ＣａＯ・７Ａｌ_２Ｏ_３，ＣａＯ・２Ａｌ_２Ｏ_３，３ＣａＯ・Ａｌ_２Ｏ_３，３ＣａＯ・３Ａｌ_２Ｏ_２・ＣａＦ_２，１１ＣａＯ・７Ａｌ_２Ｏ_３・ＣａＦ_２などのカルシウムアルミネート類、酸化カルシウム，水酸化カルシウムおよびこれらの複合塩または混合物から選ばれる１種以上が使用できる。また、液体の急結剤の場合は、上記粉体の急結剤を水などで分散した溶液として使用することができる。
【００３０】
粉体の急結剤の注入量は、耐火性骨材と耐火性粉末の合量１００重量部に対して乾量基準の重量で０．０５〜３重量部とするのが好ましく、すなわち０．０５重量部以下では急結速度が不充分で吹き付け施工後の坏土にダレが発生する。また、３重量部より多く注入すると急速に硬化して吹付施工が困難になる等の問題が生ずる。さらに、液体急結剤の注入量も水などで希釈し分散する前の実質粉末急結剤部分で０．０５〜３重量部とするのが好ましい。
【００３１】
特に、粉体の急結剤を使う場合に、急結剤添加装置による添加過程で、ブリッジングや潮解を起こし、閉塞する場合があるが、この場合は、耐火性粉末の粒子を加えると、吐出を円滑にすることができるので好ましい。
【００３２】
また、耐火性骨材と耐火性粉体の合量１００重量部に対して、０．００３〜０．２重量部の硬化遅延剤を添加すれば、混練した坏土の可使時間を好ましい範囲である２〜６時間程度まで延長でき、気温が高い夏場でも充分に可使時間を確保でき、安定して耐火物を吹付施工できる。硬化遅延剤には、シュウ酸，ホウ酸，りんご酸，クエン酸などの弱酸が好ましく使用できる。
【００３３】
【実施例】
以下、本発明の実施例について、図面を参照しながら詳細に説明する。なお、（表１）は、例１〜例６が本発明の吹き付けによる実施例、例７〜例９が流し込みによる比較例、例１０が吹き付けによる比較例を示したものである。
【００３４】
【表１】

【００３５】
（例１〜例６）
例１，２および４，５，６には、耐火性骨材として、Ａｌ_２Ｏ_３，ＳｉＯ_２およびＦｅ_２Ｏ_３の含有量がそれぞれ４３重量％，５３重量％および０．９重量％であって、粒径が１．６８〜５ｍｍの粗粒、粒径が０．１〜１．６８ｍｍの中粒、および粒径が０．０２〜０．１ｍｍで平均粒径が０．０３ｍｍの細粒からなるシャモット質骨材を用い、例３にはＡｌ_２Ｏ_３，ＳｉＯ_２およびＦｅ_２Ｏ_３の含有量がそれぞれ８９重量％，７重量％および１．３重量％であって、粒径が１．６８〜５ｍｍの粗粒、粒径が０．１〜１．６８ｍｍの中粒、および粒径が０．０２〜０．１ｍｍで平均粒径が０．０２ｍｍの細粒からなるボーキサイト質骨材を用いた。
【００３６】
耐火物の結合部を構成する耐火性粉末として、Ａｌ_２Ｏ_３とＣａＯの含有量がそれぞれ５５重量％と３６重量％で平均粒径が９μｍのアルミナセメント、Ａｌ_２Ｏ_３の純度が９９．６重量％で平均粒径が４．３μｍのバイヤーアルミナおよびＳｉＯ_２の純度が９３重量％で平均粒径が０．８μｍのヒュームドシリカを用いた。また分散剤としてＰ_２Ｏ_５とＮａ_２Ｏの含有量がそれぞれ６０．４重量％と３９．６重量％のテトラポリリン酸ナトリウムの粉末を用いた。
【００３７】
耐火性骨材と耐火性粉末および分散剤を混合して（表１）に示す粉体組成物を調合し、各組成物に（表１）に示す量の水（耐火性骨材と耐火性粉末は内掛け重量％、他はいずれも外掛け重量％）を加え、５００ｋｇ容量のボルテックスミキサー中で３分間混練して坏土とした。各坏土の流動性は、混練した坏土を上端内径５０ｍｍ，下端内径１００ｍｍ，高さ１５０ｍｍで上下端が開口した円錐台形状のコーン型に混練直後の坏土を流し込んで充たし、コーン型を上方に抜き取って６０秒間静置したときの広がり直径を２方向についてノギスで測定し、その平均値をフロー値とした。
【００３８】
例１から例４および例６では、粉末急結剤として粒径が８００μｍ以下で平均粒径が約１５０μｍの粉末であって、アルミン酸ナトリウム（約２０％の結晶水を含む）と炭酸ナトリウムを３：１の重量比で含むものを用いた。
【００３９】
例５では、液体急結剤を用い、その処方は上記粉末急結剤１００重量部を水１０００重量部で予め混合分散して使用した。（表１）では、液体急結剤中の実質的な粉末急結剤の添加量を示した。
【００４０】
吹付は図１に示す吹付施工装置によって行った。すなわち、図１の吹付施工装置を使用し、垂直な鉄板からなる壁面（アンカーは設けず）に約１００ｍｍの厚みに吹き付けるため、吹付ノズルと鉄板の距離を約１０００ｍｍになるように空気圧を調整するとともに、吹付速度を、混練した坏土で４ｔｏｎ／時間となるように調整して吹付施工を行った。施工は概ね２０℃の気温下で行った。
【００４１】
図１において、１はミキサー、３は坏土の空気搬送装置、５は輸送管、６は急結剤注入口、７はノズル配管、８は吹付ノズル、４は急結剤の添加装置、９は急結剤の輸送管、１０はエアーコンプレッサー、１１は空気ヘッダー、１２はエアードライヤー、１３，１４，１５，１６はエアーホースである。
【００４２】
ミキサー１で混練された自己流動性を有する坏土は、坏土の脱泡工程および定量供給工程を備える空気搬送装置３に矢印２のように投入され、輸送管５を通して空気搬送される。さらに空気搬送された坏土は、急結剤注入口６で急結剤を注入された後、ノズル配管７を通過し、吹付ノズル８より吹付施工される。なお、空気搬送装置３の駆動源である高圧空気は、エアーコンプレッサー１０からエアーホース１３，空気ヘッダー１１，エアーホース１４を通して供給される。
【００４３】
本実施例では、輸送管５，ノズル配管７は呼び径４０Ａであって、長さがそれぞれ２０ｍおよび２００ｍｍのゴムホースにより行った。また、急結剤注入口６は、内径で概ね輸送管５及びノズル配管７と同一であるＹ型形状のノズル管を用いた。
【００４４】
例１〜例４および例６では、定量的に粉末急結剤を注入するために、ディスクフィーダーを備える急結剤の添加装置４（本実施例では、日本プライブリコ社製のＱガン）を用い、エアーコンプレッサー１０からエアーホース１３、空気ヘッダー１１、エアーホース１５を通して高圧空気を除湿するエアードライヤー１２を通過した高圧空気を搬送源として使用した。さらに急結剤の添加装置４からは、急結剤の輸送管９を通して空気とともに急結剤を急結剤注入口６へ搬送した。
【００４５】
例５では、液体急結剤を用いており、図１における急結剤の添加装置４，エアードライヤー１２，エアーホース１５の代わりに、３連式のプランジャポンプを取り付けて、急結剤の輸送管９により液体急結剤を急結剤注入口６へ送った。なおこの場合、液体急結剤を液体ポンプにより圧力注入したが、液体急結剤を坏土に注入する前に、高圧空気を注入して高圧空気とともにミスト状とした液体急結剤を坏土に注入する方法も好ましく実施できる。
【００４６】
また、例４では、急結剤注入口６およびノズル配管７を設けずに、輸送管５と吹付ノズル８を直結し、粉末急結剤を高圧空気の混合した状態で直接吹付ノズル８に注入した。
【００４７】
図２および図３は、本実施例で使用した、坏土の脱泡工程および定量供給工程を備えた空気搬送装置３の詳細な構成を示したものである。なお、図３は図２のＡ方向から見た図である。２１は坏土２２を投入するホッパー、２３は坏土２２を下方へ導く導管、この導管２３には、粘性が高い坏土２２においてもスムーズに下方に流れるように振動を与える振動機２４が設けられている。２５は回転軸で、その周囲に配置された複数のポケット２６からなる循環ポケット群を回転させる。２７は高圧空気をポケット２６に吹き込む空気吹き込み管であって、図１のエアーホース１４が接続される。２８は材料の吐出管、２９は吐出管２８を支える支持金具である。吐出管２８は比較的長い直線部Ｂ（本実施例では直線距離で４００ｍｍとした）とそれに連続して比較的緩やかな曲がり部Ｃを有し、この吐出管２８の先には、図１の輸送管５が接続される。
【００４８】
本発明の脱泡工程および定量供給工程は、回転する複数のポケット２６へ坏土２２を自重で投入する導管２３を設け、この導管２３を通る坏土２２に対して振動機２４で振動を与えて坏土２２に含まれる空気を排除する。これにより複数のポケット２６への空気混入を著しく低減し、かつある程度粘性の高い坏土２２でも完全な供給を行うことが実現され、長時間の使用においても空気搬送量の定量性を維持することができる。
【００４９】
また、材料吐出管が２００ｍｍ以上の直線部Ｂを有することで、直線部を流れる坏土２２の空送流速が充分大きくなり、すなわち、曲がり部での流動抵抗に打ち勝つ運動エネルギーを与えることで材料坏土２２の吐出をスムーズに行い、かつ吐出抵抗を低減でき、また材料坏土２２が搬送経路に付着し著しくは閉塞するなどの問題を回避可能であるなど優れた特徴を有する。
【００５０】
例６の場合は、坏土２２の脱泡工程および定量供給工程を以下の条件で行った例である。すなわち、図２における振動機２４を動作させず、また、吐出管２８の直線部Ｂを長さ１５０ｍｍとして行い、それ以外の条件は例１と同様に行った。坏土２２の搬送時に輸送管５のゴムホースでやや脈動傾向が見られたが、例７の流し込み施工されたものと比較して施工体の嵩比重や物性はほとんど変わらない結果となった。
【００５１】
例１から例６に示す本発明の吹付施工では、吹付施工時のリバウンドと粉塵の発生がほとんどなく、特に吹付ノズル先端での耐火性骨材の分離・飛散なども見られず、従来の吹付施工方法と比べて施工歩留まりと作業環境は極めて良好であった。
【００５２】
施工壁面に厚さ約１００ｍｍに吹付施工した施工体を概ね２０℃の室内に２４時間放置し、各施工体から約３０ｃｍ×３０ｃｍの大きさの施工体試料を採取し、採取した試料を１１０℃で２４時間乾燥した後、ＪＩＳＲ２２０５に規定された方法に準じて気孔率と嵩比重を測定した。
【００５３】
（例７〜例１０）
例７〜例９は、それぞれ例１，例２，例３の坏土２２を、内寸４０ｍｍ×４０ｍｍ×１６０ｍｍの型枠に流し込み成形した不定形耐火物施工体について求めた結果である。（表１）に示された例１〜例３の本発明方法による吹付施工で得られた不定形耐火物の施工体の嵩比重や物性は、例７〜例９のそれと比較してほとんど劣らないことがわかる。また、例４で示すように粉末急結剤を吹付ノズル８で直接添加する場合や例５で示すように液体急結剤を使用する場合においても、例７の流し込み成形した場合との比較において、本発明の吹付施工により得られた不定形耐火物の施工体の嵩比重や物性がほとんど劣らないことがわかる。
【００５４】
例１０は、図１における空気搬送装置３の代わりに圧送ポンプを用いて吹き付けを行った例である。ダブルピストン式の圧送ポンプを用いて、吹付ノズルと壁面との距離が１０００ｍｍになるように空気圧を調整し、吹付速度を、混練した坏土２２で４ｔｏｎ／時間となるように調整して吹付施工を行い、それ以外の条件は例３と同様に行ったが、先端ノズル部分で耐火性骨材のリバウンドが顕著に見られたため、サンプルの採取は行っていない。
【００５５】
【発明の効果】
以上説明したように、本発明によれば、吹付施工した不定形耐火物の施工体の気孔率や嵩比重、その他の物性は、従来の型枠流し込み方法で得られる施工体のそれと比較して遜色なく、しかも、吹付による粉塵の飛散等で環境を汚染することも少ない。また、一層の省力化が可能になり、作業員への負担が軽減されるとともに、作業能率が著しく向上するという優れた効果を奏する。
【図面の簡単な説明】
【図１】本発明の実施例において使用された吹付施工装置のブロック図である。
【図２】同吹付施工装置における坏土の空気搬送装置の断面図である。
【図３】図２のＡ−Ａ矢視図である。
【符号の説明】
１…ミキサー、３…坏土の空気搬送装置、４…急結剤の添加装置、５…坏土の輸送管、６…急結剤注入口、７…ノズル配管、８…吹付ノズル、９…急結剤の輸送管、１０…エアーコンプレッサー、１１…空気ヘッダー、１２…エアードライヤー、２１…ホッパー、２２…坏土、２３…導管、２４…振動機、２６…ポケット、２７…空気吹き込み管、２８…吐出管。[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a method for spraying an irregular-shaped refractory for constructing an irregular-shaped refractory having a large strength and a large specific gravity.
[0002]
[Prior art]
The spraying of irregular-shaped refractories has the advantage that the construction work can be labor-saving compared to the casting method that requires a formwork.Therefore, the method of spraying irregular-shaped refractories has been implemented. ing.
[0003]
The conventional spraying method is a so-called dry spraying method, in which a dry, non-flowable dry amorphous refractory powder composition is conveyed to a construction site using compressed air as a carrier by piping or a rubber hose, and sprayed by a spray nozzle. Moisture required by irregular-shaped refractories is injected and sprayed from a spray nozzle.
[0004]
However, in such a method, finely dispersed in the kneaded material of the amorphous refractory powder composition, for example, 0.1 mm or less of the refractory powder particles are sprayed in an insufficiently dispersed state and wet state. Therefore, a lot of air is taken into the clay of the sprayed irregular shaped refractory, and as a result, the porosity of the sprayed irregular shaped refractory construction body is larger than that of the cast construction and Since the bulk specific gravity was small, refractory performance such as corrosion resistance was inferior.
[0005]
On the other hand, after the necessary amount of water to be originally added by the spray nozzle is added and kneaded to the powder composition for the amorphous refractory for dry spraying in advance, the compressed air is used as a carrier and piping or a rubber hose is used to bring air to the work site. It is also known to carry out wet spraying by spraying with a spray nozzle.However, a mixture obtained by adding water to the powder composition for an amorphous refractory for dry spraying and kneading the same is to remove dripping after spraying. In order to prevent this, it is essential to include a component such as clay that increases the viscosity of the clay, and a component that rapidly increases the viscosity by accelerating the setting time of the alumina cement. Has become too large, causing problems such as pulsation at the time of pneumatic conveyance and significant blockage in the piping.
[0006]
As a means for avoiding these problems, a method of spraying irregular-shaped refractories described in Japanese Patent Application No. Hei 8-116621 has been proposed. This method is useful as such, but has the following problems. I was
[0007]
That is, the self-fluidizing clay obtained by adding water to the amorphous refractory powder composition and kneading the mixture is sent to the spray nozzle by a pressure pump, and a compressed air injection port provided in front of the spray nozzle and a quick setting agent injection. Injection is performed by injecting compressed air and quick-setting agent from the inlet, respectively, but if the injection amount of compressed air is excessively large, the essential amount contained in the kneaded clay of the powder composition for amorphous refractory There has been a problem that the refractory aggregate as a component is separated and scattered by a spray nozzle.
[0008]
[Problems to be solved by the invention]
An object of the present invention is to solve the above-mentioned problems of the prior art, to further reduce labor during construction, to reduce scattering of dust to the surroundings, to reduce the porosity of the construction body, and to reduce the bulk specific gravity. It is an object of the present invention to provide a method for spraying an amorphous refractory which is large and has excellent characteristics as a refractory.
[0009]
[Means to solve the problem]
In order to achieve the above object, a method for spraying an amorphous refractory according to the present invention comprises a refractory powder comprising a refractory aggregate, alumina and / or fumed silica, and a refractory ultrafine powder having an average particle size of 10 μm or less. In addition, water is added to and kneaded with the amorphous refractory powder composition containing a small amount of a dispersant, and the obtained kneaded clay is a cone having upper and lower ends opened at an upper end inner diameter of 50 mm, a lower end inner diameter of 100 mm, and a height of 150 mm. after fills poured into cone trapezoidal, the cone-shaped spreading diameter when left to stand for 60 seconds withdrawn upwardly allowed to have a self-fluidity greater than or equal to 160 mm, then該坏earth, By blowing high-pressure air into an air transfer device having a defoaming step and a fixed-quantity supply step of the kneaded material, the kneaded material is air-conveyed through a transport pipe connected to a spray nozzle at a tip portion, and rapidly formed in the conveyed kneaded material. The required amount of quick-setting agent from the By entering, characterized by spraying installation by the spray nozzle.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
The main feature of the spraying construction method of the present invention is that the kneaded clay of an amorphous refractory having self-flowing property is pneumatically conveyed to a construction site. According to this method, since the kneaded clay of the irregular-shaped refractory in which the required moisture is previously mixed is sent to the construction site by air conveyance, the water distribution in the kneaded clay is determined by mixing and kneading the required moisture in advance. It can be uniform and sufficiently defoamed. In addition, spraying is performed without air being re-mixed into the kneaded material during air conveyance. As a result, a construction body of an amorphous refractory having a small porosity and a large bulk specific gravity is obtained.
[0011]
In the spraying construction method of the present invention, since the quick-setting agent is injected near the spraying nozzle connected to the tip of the transport pipe, the kneaded material sprayed from the spraying nozzle is rapidly self-generated by the injected quick-setting agent. Fluidity is reduced, and therefore, even when sprayed on a vertical wall surface or a ceiling wall surface, the clay can be applied without falling or falling off the wall surface.
[0012]
Further, since the clay having self-fluidity can be rapidly kneaded at the tip of the transport pipe, the composition having low viscosity and the hardening time are sufficiently long as the clay having self-fluidity. It is possible to select a composition that can maintain self-fluidity for more than an hour). It has excellent features such as observable pulsation during air conveyance and obstruction in the piping, and a sound sprayed construction can be obtained after spraying.
[0013]
When the quick setting agent is injected near the spray nozzle, the quick setting agent may be injected from a quick setting agent injection port provided directly on the spray nozzle, but a nozzle of 100 mm or more, preferably 200 mm or more between the spray nozzle and the transport pipe. If a pipe is arranged and the quick-setting agent is injected from the quick-setting agent injection port provided at the connection between the nozzle pipe or the nozzle pipe and the transport pipe, the clay and the clay are discharged before being discharged from the spray nozzle. The quick-setting agent can be uniformly mixed, and as a result, the amount of the quick-setting agent added can be reduced, and deterioration of the fire resistance performance due to unevenness of the quick-setting agent can be prevented.
[0014]
The present invention is characterized in that the pneumatic conveyance preferably includes a defoaming step of the kneaded clay and a quantitative supply step. As a more preferable embodiment of the defoaming step and the quantitative supply step, in a pneumatic conveying device (spraying device) provided with a rotor having a plurality of pockets, a conduit for charging the clay by its own weight into the pockets is provided. By vibrating the material, air mixed into the kneaded material during kneading can be significantly reduced. In addition, even if the clay has high viscosity to some extent, complete supply can be performed by vibrating, and the quantitativeness of the air conveyance amount can be maintained even when used for a long time.
[0015]
In the air conveyance, the kneaded material is transferred using high-pressure air as a carrier, but when the supply speed of the kneaded material is not constant, the transfer pressure loss of the kneaded material fluctuates, and as a result, the air flow rate also fluctuates, and pulsation occurs. As a result, the discharge amount of the kneaded clay at the tip of the spray nozzle fluctuates, causing a problem such as an uneven structure after application.However, the air conveyance according to the present invention includes a defoaming step and a constant-quantity supply step of the kneaded kneaded clay. By doing so, it has excellent features such as the ability to avoid these problems.
[0016]
In the air conveyance after the defoaming step and the fixed-quantity supply step, the discharge resistance of the material kneaded material can be reduced by having the transport pipe linear portion of 200 mm or more at the material discharge port, and the material kneaded material adheres to the inside of the transport pipe. However, it has an excellent feature that a problem such as remarkable blockage can be avoided.
[0017]
In the pneumatic conveyance of the present invention, the kneaded material is transported by using a pipe or a rubber hose, and a blowing hose is usually operated by a worker who freely operates the blowing nozzle as a rubber hose of about 10 m before the blowing nozzle. The inside of the rubber hose portion held by the worker is very light because the clay is floating in the air, so that the working labor can be reduced.
[0018]
In the present invention, the fluidity of the clay is evaluated using a cone type. That is, at about 20 ° C., the kneaded clay immediately after adding water of about 20 ° C. to the amorphous refractory powder composition at a temperature of about 20 ° C., and having an upper end inner diameter of 50 mm, a lower end inner diameter of 100 mm, a height of 150 mm, and upper and lower ends. The diameter of the spread when the kneaded clay immediately after kneading is poured into an open truncated cone-shaped cone mold and the cone mold is withdrawn upward and allowed to stand for 60 seconds (an average value obtained by measuring the spread in two directions, hereinafter referred to as a flow value) ).
[0019]
The kneaded material exhibits self-fluidity if the flow value is 150 mm or more. However, in order to stably carry the air, the flow value of the clay is preferably 160 mm or more, more preferably 180 mm or more. If the clay having a large flow value is used, the resistance of air conveyance can be reduced, the diameter of the pipe or hose to be conveyed can be reduced, and long distance transportation of the clay can be realized.
[0020]
The powder composition used in the present invention contains a refractory aggregate, a refractory powder and a small amount of a dispersant. The refractory powder fills the gaps between the refractory aggregates to form a joint that joins the refractory aggregates. Examples of refractory aggregates include alumina, bauxite, diaspore, mullite, ban shale, chamotte, silica, pyrophyllite, silymanite, andalusite, chromite, spinel, magnesia, zirconia, zircon, chromia, silicon nitride, One or more selected from carbon such as aluminum nitride, silicon carbide, boron carbide and graphite, titanium boride and zirconium boride are preferred.
[0021]
Examples of the refractory powder include alumina cement, alumina, titania, bauxite, diaspore, mullite, ban shale, chamotte, pyrophyllite, sillimanite, andalusite, quartzite, chromite, spinel, magnesia, zirconia, zircon, chromia , Silicon nitride, aluminum nitride, silicon carbide, boron carbide, titanium boride, zirconium boride, and amorphous silica such as fumed silica, and preferably has an average particle size of 30 μm or less.
[0022]
As a part of these refractory powders, when the average particle size of alumina or fumed silica is 10 μm or less, preferably 5 μm or less, the amount of water to be added to the clay of the composition is reduced. And good self-fluidity can be imparted to the kneaded clay.
[0023]
If alumina cement is used as a part of the refractory powder, the alumina cement functions as a binder for the amorphous refractory, and the construction body can maintain strength in a wide range from normal temperature to high temperature.
[0024]
As a means for imparting good self-flowability to the clay, it is preferable that a powder dispersant selected according to the type of refractory aggregate and refractory powder to be used is blended in the powder composition. . The dispersant is preferably at least one selected from polymetaphosphates, polycarboxylates, polyacrylates and β-naphthalenesulfonates, and the total amount of the refractory aggregate and refractory powder of the powder composition. It is preferable to add 0.02 to 1 part by weight to 100 parts by weight.
[0025]
Moisture added to the powder composition for the amorphous refractory is to reduce the porosity of the applied amorphous refractory to ensure good properties as a refractory, based on 100 parts by weight of the powder composition It is preferably 15 parts by weight or less, more preferably 12 parts by weight or less. If the water content of the kneaded clay is low, it is possible to suppress the refractory aggregate contained in the kneaded clay from settling and the kneaded clay from becoming heterogeneous. can get.
[0026]
As the quick setting agent to be injected into the kneaded material, a powder or a liquid can be used. When a liquid quick-setting agent is used, it is not preferable to excessively increase the liquid (usually using water) because the denseness of the construction body after spraying decreases.
[0027]
A device capable of uniformly controlling the amount of powder to be added can be preferably used for the transfer of the powder quick-setting admixture. Usually, a device for conveying the quick-setting admixture using compressed air as a carrier is used.
[0028]
Further, the liquid quick-setting agent is also preferably a liquid pump capable of uniformly controlling the supply amount, and it is necessary to appropriately select a liquid quick-setting agent according to the type of the quick-setting agent to be used. A plunger pump, a diaphragm pump, and the like are preferable. You.
[0029]
Examples of powder quick setting agents include aluminates such as sodium aluminate, potassium aluminate and calcium aluminate, carbonates such as sodium carbonate, potassium carbonate, sodium bicarbonate and potassium bicarbonate, sodium sulfate, potassium sulfate, and the like. sulfates such as magnesium _{_{_{_{sulfate, CaO · Al 2 O 3,}}}} 12CaO · 7Al 2 O 3, CaO · 2Al 2 O 3, 3CaO · Al 2 O 3, 3CaO · 3Al 2 O 2 · CaF 2, 11CaO · 7Al 2 O _At least one selected from calcium aluminates such as 3.CaF ₂ , calcium oxide, calcium hydroxide, and composite salts or mixtures thereof can be used. In the case of a liquid quick setting agent, the powder quick setting agent can be used as a solution in which water is dispersed.
[0030]
The amount of the powder quick setting agent to be injected is preferably 0.05 to 3 parts by weight on a dry basis with respect to 100 parts by weight of the total amount of the refractory aggregate and the refractory powder. If the amount is less than 05 parts by weight, the rapid setting speed is insufficient, and dripping occurs in the kneaded material after spraying. Further, if more than 3 parts by weight is injected, there is a problem that the material is rapidly cured and spraying becomes difficult. Further, the injection amount of the liquid quick-setting admixture is preferably 0.05 to 3 parts by weight in the substantial powder quick-setting admixture before being diluted and dispersed with water or the like.
[0031]
In particular, when using a powder quick-setting admixture, bridging or deliquescence may occur during the addition process using the quick-setting additive adding device, and the plug may be clogged.In this case, when particles of the refractory powder are added, This is preferable because the discharge can be made smooth.
[0032]
If 0.003 to 0.2 parts by weight of a curing retarder is added to 100 parts by weight of the total amount of the refractory aggregate and the refractory powder, the pot life of the kneaded clay is in a preferable range. It can be extended to about 2 to 6 hours, so that the pot life can be sufficiently secured even in summer when the temperature is high, and the refractory can be sprayed stably. Weak acids such as oxalic acid, boric acid, malic acid and citric acid can be preferably used as the curing retarder.
[0033]
【Example】
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In Table 1, Examples 1 to 6 show Examples by spraying of the present invention, Examples 7 to 9 show Comparative Examples by casting , and Example 10 show Comparative Examples by spraying .
[0034]
[Table 1]

[0035]
(Examples 1 to 6)
In Examples 1, 2 and 4, 5, 6, the content of Al ₂ O ₃ , SiO ₂ and Fe ₂ O ₃ as the refractory aggregate was 43% by weight, 53% by weight and 0.9% by weight, respectively. Coarse particles having a particle size of 1.68 to 5 mm, medium particles having a particle size of 0.1 to 1.68 mm, and fine particles having a particle size of 0.02 to 0.1 mm and an average particle size of 0.03 mm. In Example 3, the content of Al ₂ O ₃ , SiO ₂ and Fe ₂ O ₃ was 89% by weight, 7% by weight and 1.3% by weight, respectively. Consisting of coarse particles of 1.68 to 5 mm, medium particles of 0.1 to 1.68 mm in diameter, and fine particles of 0.02 to 0.1 mm in particle diameter and 0.02 mm in average particle diameter Aggregate was used.
[0036]
As the refractory powder constituting the coupling portion of the refractory, _Al 2 _{O 3} and CaO average particle diameter 9μm alumina cement content is 55 wt% and 36 wt% each, the purity of _Al 2 _{O 3} is 99. Bayer alumina having an average particle diameter of 4.3 μm and fumed silica having a purity of 93% by weight and SiO ₂ having an average particle diameter of 0.8 μm were used. As the dispersant, powder of sodium tetrapolyphosphate having contents of P ₂ O ₅ and Na ₂ O of 60.4% by weight and 39.6% by weight, respectively, was used.
[0037]
The powder composition shown in (Table 1) is prepared by mixing the refractory aggregate, the refractory powder and the dispersant, and the amount of water (refractory aggregate and fire resistance) shown in (Table 1) is added to each composition. The powder was added by inner weight%, and the others were added by outer weight%), and kneaded in a 500 kg vortex mixer for 3 minutes to obtain a clay. The fluidity of each kneaded clay is determined by pouring the kneaded kneaded clay immediately after kneading into a cone-shaped cone having an upper end inner diameter of 50 mm, a lower end inner diameter of 100 mm, a height of 150 mm, and open upper and lower ends. The spread diameter when the sample was pulled out and allowed to stand for 60 seconds was measured with calipers in two directions, and the average value was defined as the flow value.
[0038]
In Examples 1 to 4 and 6, the powder quick-setting agent is a powder having a particle diameter of 800 μm or less and an average particle diameter of about 150 μm, and contains sodium aluminate (containing about 20% water of crystallization) and sodium carbonate. Those containing at a weight ratio of 3: 1 were used.
[0039]
In Example 5, a liquid quick-setting admixture was used, and 100 parts by weight of the above-mentioned powder quick-setting admixture were previously mixed and dispersed in 1000 parts by weight of water. Table 1 shows the substantial amount of the powder quick-setting additive in the liquid quick-setting additive.
[0040]
Spraying was performed by the spraying construction apparatus shown in FIG. In other words, the air pressure is adjusted so that the distance between the spray nozzle and the iron plate is about 1000 mm in order to use the spraying construction apparatus shown in FIG. 1 to spray the wall of a vertical steel plate (without anchors) to a thickness of about 100 mm. At the same time, the spraying speed was adjusted with the kneaded clay to 4 ton / hour, and spraying was performed. The construction was performed at a temperature of approximately 20 ° C.
[0041]
In FIG. 1, 1 is a mixer, 3 is an air conveying device for kneaded material, 5 is a transport pipe, 6 is a quick-setting agent injection port, 7 is a nozzle pipe, 8 is a spray nozzle, 4 is a quick-setting agent adding device, 9 Is a transport pipe for a quick-setting agent, 10 is an air compressor, 11 is an air header, 12 is an air dryer, and 13, 14, 15, and 16 are air hoses.
[0042]
The kneaded clay having self-fluidity kneaded by the mixer 1 is introduced as shown by an arrow 2 into an air transport device 3 having a defoaming step and a constant-quantity supply step of the kneaded clay, and is pneumatically transported through a transport pipe 5. Further, the kneaded material conveyed by air is injected with the quick setting agent at the quick setting agent injection port 6, passes through the nozzle pipe 7, and is sprayed from the spray nozzle 8. The high-pressure air, which is the driving source of the air transfer device 3, is supplied from the air compressor 10 through the air hose 13, the air header 11, and the air hose 14.
[0043]
In the present embodiment, the transport pipe 5 and the nozzle pipe 7 are formed of rubber hoses having a nominal diameter of 40A and lengths of 20 m and 200 mm, respectively. As the quick-setting agent injection port 6, a Y-shaped nozzle pipe whose inner diameter is substantially the same as the transport pipe 5 and the nozzle pipe 7 is used.
[0044]
In Examples 1 to 4 and 6, in order to quantitatively inject the powder quick-setting agent, a quick-setting agent addition device 4 having a disk feeder (in this example, a Q gun manufactured by Nippon Pribrico Co., Ltd.) was used. The high-pressure air passed through an air dryer 12 for dehumidifying the high-pressure air from an air compressor 10 through an air hose 13, an air header 11, and an air hose 15 was used as a transport source. Further, the quick-setting agent was conveyed to the quick-setting agent inlet 6 together with air from the quick-setting agent adding device 4 through a quick-setting agent transport pipe 9.
[0045]
In Example 5, a liquid quick-setting agent is used, and instead of the quick-setting agent adding device 4, the air dryer 12, and the air hose 15 in FIG. 1, a triple-type plunger pump is attached to transport the quick-setting agent. The liquid quick-setting agent was sent to the quick-setting agent inlet 6 through the pipe 9. In this case, the liquid quick-setting agent was pressure-injected by the liquid pump, but before the liquid quick-setting agent was injected into the kneaded material, high-pressure air was injected into the kneaded material to form a mist-like liquid quick-setting agent. Is also preferably carried out.
[0046]
In Example 4, the transporting pipe 5 was directly connected to the spray nozzle 8 without providing the quick-setting agent injection port 6 and the nozzle pipe 7, and the powder quick-setting agent was directly injected into the spray nozzle 8 in a state of mixing high-pressure air. did.
[0047]
FIG. 2 and FIG. 3 show a detailed configuration of the pneumatic conveying device 3 used in the present embodiment and provided with a kneaded clay defoaming step and a quantitative supply step. FIG. 3 is a diagram viewed from the direction A in FIG. Reference numeral 21 denotes a hopper for charging the kneaded clay 22, 23 denotes a conduit for guiding the kneaded clay 22 downward, and a vibrator 24 for vibrating the kneaded clay 22 so as to smoothly flow downward even in the highly viscous kneaded clay 22 is provided. Have been. A rotation shaft 25 rotates a circulation pocket group including a plurality of pockets 26 arranged around the rotation shaft. Reference numeral 27 denotes an air blowing pipe for blowing high-pressure air into the pocket 26, to which the air hose 14 of FIG. 1 is connected. Reference numeral 28 denotes a discharge pipe for the material, and 29 denotes a support fitting for supporting the discharge pipe 28. The discharge pipe 28 has a relatively long straight portion B (in this embodiment, the linear distance is 400 mm) and a relatively gentle bend C continuously from the straight portion B. The transport pipe 5 is connected.
[0048]
In the defoaming step and the constant-quantity supply step of the present invention, a conduit 23 for charging the clay 22 by its own weight into a plurality of rotating pockets 26 is provided, and vibration is applied to the clay 22 passing through the conduit 23 by a vibrator 24. To remove the air contained in the clay 22 . This significantly reduces air entrapment into the plurality of pockets 26 and achieves complete supply even with the clay 22 having a certain degree of viscosity, and maintains the quantitativeness of the air transport amount even during long-term use. Can be.
[0049]
In addition, since the material discharge pipe has the straight portion B of 200 mm or more, the air flow velocity of the clay 22 flowing in the straight portion becomes sufficiently large, that is, the material is provided by imparting kinetic energy that overcomes the flow resistance in the bent portion. smoothly perform ejection of the clay 22, and reduces the discharge resistance, also significantly material clay 22 adheres to the conveyance path having excellent characteristics such as being possible to avoid problems such as clogging.
[0050]
The case of Example 6 is an example in which the defoaming step and the quantitative supply step of the clay 22 were performed under the following conditions. That is, the vibrator 24 in FIG. 2 was not operated, the straight section B of the discharge pipe 28 was set to have a length of 150 mm, and the other conditions were the same as in Example 1. Although a slight pulsation tendency was observed with the rubber hose of the transport pipe 5 when the kneaded material 22 was transferred, the bulk specific gravity and the physical properties of the construction body were hardly changed as compared with the case where the casting was performed in Example 7.
[0051]
In the spraying construction of the present invention shown in Examples 1 to 6, there is almost no rebound and dust generation during the spraying construction, and particularly no separation or scattering of the refractory aggregate at the tip of the spraying nozzle is observed. Compared with the construction method, the construction yield and working environment were extremely good.
[0052]
The construction body sprayed to a thickness of about 100 mm on the construction wall surface was left in a room at approximately 20 ° C. for 24 hours, and a construction body sample having a size of about 30 cm × 30 cm was collected from each construction body. After drying for 24 hours, the porosity and the bulk specific gravity were measured according to the method specified in JIS R2205.
[0053]
(Examples 7 to 10)
Examples 7 to 9 are the results obtained for irregularly shaped refractory constructions in which the clay 22 of Example 1, Example 2, and Example 3 was cast into a mold having an inner size of 40 mm x 40 mm x 160 mm. The bulk specific gravity and physical properties of the refractory molded bodies obtained by spraying according to the method of the present invention of Examples 1 to 3 shown in (Table 1) are almost inferior to those of Examples 7 to 9. I understand that there is no. Also, in the case where the powder quick-setting agent is directly added by the spray nozzle 8 as shown in Example 4 or the case where the liquid quick-setting agent is used as shown in Example 5, in comparison with the case where the casting is carried out in Example 7. It can be seen that the bulk specific gravity and the physical properties of the irregularly shaped refractory construction body obtained by the spraying construction of the present invention are hardly inferior.
[0054]
Example 10 is an example in which spraying is performed using a pressure feed pump instead of the air transfer device 3 in FIG. Using a double piston type pressure pump, the air pressure is adjusted so that the distance between the spray nozzle and the wall surface is 1000 mm, and the spray speed is adjusted so that the kneaded clay 22 becomes 4 ton / hour. The other conditions were the same as in Example 3, but no sample was collected because rebound of the refractory aggregate was remarkably observed at the tip nozzle portion.
[0055]
【The invention's effect】
As described above, according to the present invention, the porosity and the bulk specific gravity of the construction body of the spray-formed irregular-shaped refractory, and other physical properties are compared with those of the construction body obtained by the conventional casting method. There is no inferiority to the environment due to scattering of dust by spraying. Further, it is possible to further reduce labor, to reduce the burden on the worker, and to achieve an excellent effect that the working efficiency is remarkably improved.
[Brief description of the drawings]
FIG. 1 is a block diagram of a spray application device used in an embodiment of the present invention.
FIG. 2 is a sectional view of a kneaded material air transfer device in the spraying construction device.
FIG. 3 is a view as viewed in the direction of arrows AA in FIG. 2;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Mixer 3 Air-conveying device of kneaded material 4 ... Addition device of quick-setting agent 5 ... Conveying pipe of kneaded material 6 ... Quick-setting agent inlet 7 ... Nozzle piping 8 ... Blowing nozzle 9 ... 10: Air compressor, 11: Air header, 12: Air dryer, 21: Hopper, 22: Clay, 23: Conduit, 24: Vibrator, 26: Pocket, 27: Air blowing pipe, 28 ... Discharge pipe.

Claims

Water is added to a refractory powder including a refractory aggregate, alumina and / or a refractory ultrafine powder having an average particle diameter of 10 μm or less composed of fumed silica, and an amorphous refractory powder composition including a small amount of a dispersant. The obtained kneaded clay is poured into a truncated cone-shaped cone having an upper end inner diameter of 50 mm, a lower end inner diameter of 100 mm, a height of 150 mm, and an open upper and lower end, and is filled. seconds standing spread diameter upon the allowed to have a self-fluidity greater than or equal to 160 mm, then the該坏soil, the high pressure air to the air transport apparatus having a defoaming step and the dosing steps該坏soil By blowing, the air is conveyed through the transport pipe connected to the spray nozzle at the tip, and the required amount of quick-setting agent is injected into the conveyed clay from the quick-setting agent injection port, and spraying is performed by the spray nozzle. Indefinite form characterized by Spray construction method of fire products.

2. The quick-setting agent according to claim 1, further comprising a nozzle pipe between the spray nozzle and the transport pipe, and injecting a quick-setting agent from a quick-setting agent injection port provided at the nozzle pipe or at a connection between the transport pipe and the nozzle pipe. Spray construction method for irregular refractories.

3. The method for spraying irregular shaped refractories according to claim 1, wherein the quick-setting agent is a powder, the quick-setting agent is carried by compressed air, and the quick-setting agent is injected together with the compressed air from a quick-setting agent injection port. .

The method for spraying irregular shaped refractories according to claim 1 or 2, wherein the quick-setting agent is a liquid, and the quick-setting agent is transported by a liquid pump and injected through a quick-setting agent injection port.

The kneaded kneaded material to be pneumatically conveyed, when discharging the material by compressed air after the defoaming step and the fixed-quantity supply step, spraying the irregular-shaped refractory according to any one of claims 1 to 4 through a straight section of a transport pipe of 200 mm or more. Construction method.

The method of spraying irregular shaped refractories according to any one of claims 1 to 5, wherein the refractory powder contains alumina cement as a part.