JP2004160371A

JP2004160371A - Crusher and crushing method

Info

Publication number: JP2004160371A
Application number: JP2002329951A
Authority: JP
Inventors: Tetsuya Tanaka; 哲也田中; Nobuyasu Makino; 信康牧野; Hideyuki Santo; 秀行山東
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 2002-11-13
Filing date: 2002-11-13
Publication date: 2004-06-10
Anticipated expiration: 2022-11-13
Also published as: JP4025179B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a crusher apparatus with which a crushed particle having a required particle size can be obtained in a high efficiency by improving the colliding and crushing efficiency in a crushing chamber and to shorten the production grade changing time. <P>SOLUTION: This crusher is provided with two or more crushing nozzles 5, the crushing chamber 4 in which a supplied material to be crushed is crushed by the compressed air jetted from the nozzles 5 and a rotor 3 at least. The crushed material made to flow in the rotor 3 from the chamber 4 is sorted into fine powder and coarse powder by centrifugation. The nozzles 5 are arranged so that the compressed air jetted from one of the nozzles 5 is made to collide primarily against that jetted from other nozzles 5 together with the material to be crushed. A secondary collision means 6 is arranged so that the compressed air and crushed material after being subjected to the primary collision is made to collide secondarily against the secondary collision means 6. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は電子写真、静電記録、静電印刷などにおける静電荷像を現像するための乾式トナーの粉砕装置並びに粉砕方法に関し、特に流動層式粉砕装置、粉砕方法に関する。
【０００２】
【従来の技術】
従来から、ミクロンオーダーの粉体材料を製造する流動層式粉砕装置は、複数の粉砕ノズル、粉砕室、および粉砕室の上方に回転するロータによって構成されている。かかる流動層式粉砕装置においては、供給された粉体材料は複数の粉砕ノズルから噴射される圧縮空気によって加速され、粉体材料同士が衝突し粉砕作用を受け、さらに粉砕された粉体材料は粉砕室の上方に設けられた回転するロータ方向に導かれ、所望の粒径以下の粉体材料はロータの内側に回収され、所望の粒径以上の粉体材料はロータの外側に導かれ再び粉砕室に戻り粉砕作用を受ける。
【０００３】
図４に基づいて、従来の流動層式粉砕装置の構成、動作を詳しく説明する。
図４は従来の流動層式粉砕装置の断面図であり、図４において、１は粉体材料が供給される供給管を、２はエアーと共に粉砕された粉体材料が排出される排気管を、３は粉砕された粉体材料を分級するロータを、４は粉砕室を、５は粉砕室４に送り込まれる圧縮空気を搬送する粉砕ノズルをそれぞれ示す。なお、粉砕装置本体全体は略円筒状の筐体からなる。
【０００４】
図４に示す従来の粉砕装置においては、先ず、粉砕室４内部には一定量の粉体材料が充満され、次に粉砕ノズル５から圧縮空気が搬送され、該対向する粉砕ノズル５から供給された空気は、対向する各々の粉砕ノズル５の出口延長線が交わる付近、即ち粉砕室４の中心軸付近で衝突する。このとき空気に導かれ加速された粉体材料も、粉砕室４の中心軸付近で衝突し、粉砕作用を受ける。一方、排気管２と連通する吸引ファン等の吸引器（図示せず）により吸引を行なうと、粉砕された粉体材料は、排気管２に向かう。このとき、粉砕室４上部に設置されているロータ３が回転しているので、所望の粒径に粉砕された粉体材料は排気管２より排出されるが、所望の粒径よりも大きな粉体材料はロータ３の遠心力によってロータ３の外側に導かれ粉砕室４の壁面を沿って下方に導かれ、再び粉砕作用を受けることとなる。また、所望の粒径に粉砕された粉体材料は排気管２より排出されるため、粉砕室４内部の粉体材料の量は減少することから、供給管１より粉体材料を供給し、常に粉砕室４内部の粉体材料の量が一定になるように設定すれば連続粉砕を行う。
【０００５】
このように、従来の流動層式粉砕装置においては連続粉砕は可能である。
しかしながら、従来の流動層式粉砕装置においては、所望の粒径を得るためには粉砕室内部でのくり返し粉砕が必要であり、粉砕効率を低下させる原因の一つになっている。
【０００６】
粉砕効率を向上させるための装置としては、例えば、特開２０００−００５６２１号公報（特許文献１）がある。特許文献１には、衝突部材をその中心が粉砕室の中心軸上に位置するように設置し、当該部材に対して、被粉砕物を含む高速ガスを垂直に噴射させ、被粉砕物を、衝突部材に衝突させることにより粉砕し、所望粒径の粉砕物を効率よく得ることが開示されている。
【０００７】
しかしながら、特許文献１に開示されている流動層式粉砕装置においては、ノズルから噴射される高速ガス、さらに粉砕室内部の被粉砕物を、衝突部材に衝突させる際に、粉砕ノズル圧力を上げなければならないという問題がある。なぜなら、図４に示すような、従来の流動層式粉砕装置においては、高速ガスが対向するノズルから噴射されるので、粉体材料同士が高速ガスと共に加速された相対速度を持って衝突し粉砕作用を受けるのに対し、特許文献１の装置においては、高速ガスと共に粉体材料同士の相対速度が加速されることがないので、図４に示す装置と同様な粉砕効果を得るには、粉砕ノズル圧力を上げて、より高速で被粉砕物を衝突部材に衝突させなければならないからである。また、ノズルから噴射された高速ガスによって被粉砕物は衝突部材に衝突するものの、所望の粒径を得るためには粉砕室内部でのくり返し粉砕が必要であり、粉砕効率を低下させる原因の一つになっている。
【０００８】
更に、近年の高画質化要求に伴い、粉砕装置には、小粒径化、少量多品種に対応するために、従来の装置よりも品種切り替え時間を短縮することが望まれている。
【０００９】
【特許文献１】
特開２０００−００５６２１号公報
【００１０】
【発明が解決しようとする課題】
本発明は、これらの問題点を解決するためのものであり、粉砕装置の粉砕室内での衝突粉砕効率向上を達成し、必要とする大きさの範囲の粒子を高効率で粉砕することができる粉砕装置の提供することを第一の課題とし、品種切り替え時間を短縮することを第二の課題とする。
【００１１】
【課題を解決するための手段】
本発明によれば、以下に示す粉砕装置および粉砕方法が提供される。
〔１〕複数の粉砕ノズルと、該粉砕ノズルから噴射される圧縮空気によって供給された粉体材料を粉砕する粉砕室と、回転するロータとを少なくとも有し、該粉砕室から該ロータ内部に流入する粉体材料を微粉と粗粉とに遠心分級する、粉砕装置において、該複数の粉砕ノズルから噴射される圧縮空気どうしが粉体材料を伴って一次衝突するように各粉砕ノズルを設け、該一次衝突した圧縮空気及び粉体材料が二次衝突する二次衝突手段を設けたことを特徴とする粉砕装置。
〔２〕前記二次衝突手段が、粉砕ノズルから噴射される圧縮空気どうしが粉体材料を伴って一次衝突する位置の上方及び／又は下方に設けられた衝突部材に、該一次衝突した圧縮空気及び粉体材料が二次衝突する手段であることを特徴とする前記〔１〕に記載の粉砕装置。
〔３〕前記衝突部材が円筒と円錐を組み合わせた形状からなり、該円錐がその底面を円筒の一方の底面に接するように設けられた形状であることを特徴とする前記〔２〕に記載の粉砕装置。
〔４〕前記衝突部材を構成する円錐の頂点が、粉砕ノズルから噴射される圧縮空気どうしが粉体材料を伴って一次衝突する位置の１０〜５００ｍｍ真上及び／又は真下に位置するように、二次衝突部材を設けることを特徴とする前記〔３〕に記載の粉砕装置。
〔５〕前記衝突部材の高さが調節可能であることを特徴とする前記〔２〕〜〔４〕のいずれかに記載の粉砕装置。
〔６〕前記二次衝突部材が着脱可能であることを特徴とする前記〔２〕〜〔５〕のいずれかに記載の粉砕装置。
〔７〕前記二次衝突部材が耐摩耗処理を施されていることを特徴とする前記〔２〕〜〔６〕のいずれかに記載の粉砕装置。
〔８〕前記粉砕ノズルが２〜８個設けられていることを特徴とする前記〔１〕〜〔７〕のいずれかに記載の粉砕装置。
〔９〕前記粉砕ノズルが、粉砕室の縦方向の中心軸を中心とする同心円上に等間隔に設けられていることを特徴とする前記〔１〕〜〔８〕のいずれかに記載の粉砕装置。
〔１０〕前記粉砕ノズルの出口方向が、水平方向を基準にして上下２０°以内を向いていることを特徴とする前記〔１〕〜〔９〕のいずれかに記載の粉砕装置。
〔１１〕複数の粉砕ノズルから圧縮空気を噴射し、該圧縮空気どうしを粉体材料を伴わせて粉砕室の中で一次衝突させて、該粉体材料を粉砕する粉砕方法において、該一次衝突した圧縮空気及び粉体材料を二次衝突させる手段を設けることを特徴とする粉砕方法。
〔１２〕前記二次衝突手段が、粉砕ノズルから噴射される圧縮空気どうしを粉体材料を伴わせて一次衝突させる位置の上方及び／又は下方に設けられた衝突部材に、該一次衝突した圧縮空気及び粉体材料を二次衝突させる手段であることを特徴とする前記〔１１〕に記載の粉砕方法。
〔１３〕前記衝突部材が円筒と円錐からなり、該円錐がその底面を円筒の一方の底面に接するように設けられた形状であることを特徴とする前記〔１２〕に記載の粉砕方法。
〔１４〕前記衝突部材を構成する円錐の頂点が、粉砕ノズルから噴射される圧縮空気どうしを一次衝突させる位置の１０〜５００ｍｍ真上及び／又は真下に位置するように、衝突部材を設けることを特徴とする前記〔１３〕に記載の粉砕方法。
〔１５〕前記衝突部材を構成する円錐の頂点の位置を粉砕条件に対応させて上下させることを特徴とする前記〔１２〕〜〔１４〕のいずれかに記載の粉砕方法。
〔１６〕前記複数の粉砕ノズルの各々の出口方向が、水平方向を基準にして上下２０°以内を向くように設定して、該複数の粉砕ノズルから圧縮空気を噴射することを特徴とする前記〔１１〕〜〔１５〕いずれかに記載の粉砕方法。
〔１７〕前記粉砕ノズルに供給する圧縮空気の元圧力を０．２〜１．０ＭＰａに設定することを特徴とする前記〔１１〕〜〔１６〕のいずれかに記載の粉砕方法。
〔１８〕前記二次衝突させた粉体材料を、回転するロータに流入させて、微粉と粗粉とに遠心分級することを特徴とする前記〔１１〕〜〔１７〕のいずれかに記載の粉砕方法。
〔１９〕前記ロータの回転周速度が、２０〜７０ｍ／ｓであることを特徴とする前記〔１８〕に記載の粉砕方法。
【００１２】
【発明の実施の形態】
以下、図面に基づいて本発明の粉砕装置および粉砕方法について詳細に説明する。まず、本発明の粉砕装置について説明する。
本発明の粉砕装置は、複数の粉砕ノズルと、該粉砕ノズルから噴射される圧縮空気によって供給された粉体材料を粉砕する粉砕室と、回転するロータとを少なくとも有する。本発明の粉砕装置は、このように構成されているので、粉砕室内で粉砕材料を微粉と粗粉に粉砕し、さらに粉砕された微粉と粗粉を回転するロータで遠心分級することができる。
【００１３】
本発明の粉砕装置の好ましい一例を図１に示す。尚、図１は本発明の粉砕装置の一例を示す断面図である。但し、図１は本発明を限定するものではない。
図１に示す態様の粉砕装置においては、複数の粉砕ノズル５と、粉砕ノズル５から噴射される圧縮空気によって供給された粉体材料を粉砕する粉砕室４と、回転するロータ３とを有する。本発明においては、図１に示すように、ロータ３は粉砕室４の上部に設けられていることが好ましい。ロータ３が粉砕室４の上部に設けられていると、粉砕された微粉と粗粉を粉砕室４から直接ロータ３内部に流入させて、微粉と粗粉とに遠心分級することができる。
【００１４】
粉砕室４の形状に制限はないが、粉体材料を均一に供給し均一に粉砕することができるという観点から、通常は円筒状が好ましい。又、粉砕室４の大きさにも制限はないが、多量の粉体材料を効率的に粉砕できるという観点から、内径１００〜１０００ｍｍ、高さ３００〜３０００ｍｍが好ましく、内径３００〜９００ｍｍ、高さ７００〜２７００ｍｍがより好ましく、内径５００〜８００ｍｍ、高さ１０００〜２５００ｍｍが更に好ましい。
【００１５】
本発明の粉砕装置においては、複数の粉砕ノズル５が、該粉砕ノズル５から噴射される圧縮空気どうしが粉体材料を伴って一次衝突するように設けられている。この一次衝突により、供給された粉体材料は最初の破砕作用を受ける。
【００１６】
粉砕ノズル５の数に制限はないが、２〜８個の粉砕ノズルを用いることが好ましく、２〜６個の粉砕ノズルを用いることがより好ましく、３〜４個の粉砕ノズルを用いることが更に好ましい。単一の粉砕ノズルでは、圧縮空気どうしを粉体材料を伴って一次衝突させることができない。一方、粉砕ノズル５の数が多すぎると、装置の製作が煩雑となり、破砕効率がかえって低下する虞がある。
【００１７】
粉砕ノズル５は、噴射される圧縮空気どうしが粉砕室の中心軸上で衝突するように、粉砕室の縦方向の中心軸を中心とする同心円上に設けることが好ましく、粉体材料が均一に衝突するように、該同心円上に等間隔（当角度）で設けることが好ましい。但し、本明細書において、圧縮空気どうしが粉砕室の中心軸上で衝突するとは、粉砕室の中心軸上付近で衝突することを含む意味である。
【００１８】
粉砕ノズル５の出口方向は、水平方向を基準にして上下２０°以内を向いていることが好ましく、上下１５°以内を向いていることがより好ましく、上下１０°以内を向いていることが更に好ましく、０°（水平方向）を向いていることが特に好ましい。該方向が、上下２０°を超えると、粉砕効率が悪くなる虞がある。
【００１９】
本発明の粉砕装置においては、前記一次衝突した圧縮空気及び粉体材料が二次衝突する二次衝突手段が設けられている。かかる二次衝突手段により、前記一次衝突後の粉体材料をさらに衝突させると、粉砕確率が増加するため、粉砕室での粉砕効率を向上させることができる。
【００２０】
本発明における二次衝突手段は、粉砕ノズル５から噴射される圧縮空気どうしが粉体材料を伴って一次衝突する位置１３（図１に示す。）の上方及び／又は下方に設けられた衝突部材に、該一次衝突した圧縮空気及び粉体材料が二次衝突する手段であることが好ましい。かかる二次衝突部材を設けることにより、粉体材料を二次衝突させると粉砕確率が確実に増加するため、粉砕室での粉砕効率を確実に向上させることができる。
【００２１】
本発明において、粉砕ノズル５から噴射される圧縮空気どうしが粉体材料を伴って一次衝突する位置１３は、具体的には、粉砕ノズル５の中心線１２どうしが交わる位置によって定められる。
【００２２】
上記衝突部材は、図１に示すように、一次衝突する位置１３の下方に設けてもよく、図２に示すように、一次衝突する位置１３の上方に設けてもよく、図３に示すように、一次衝突する位置１３の上方と下方の双方に設けてもよい。
以下、下方に設けた二次衝突部材を第一衝突部材６、上方に設けた二次衝突部材を第二衝突部材７という。
【００２３】
本発明における二次衝突部材は、特にその形状に制限はないが、衝突板に確実に粉体材料が衝突するような形状および、寸法が必要であり、衝突板の後流も考慮する必要がある。かかる観点から、該二次衝突部材は、図５、図６に示すように、円筒と円錐からなり、該円錐がその底面を円筒の一方の底面に接するように設けられた形状であることが好ましく、該円錐の頂点が一次衝突する位置１３を向くように設けられていることが好ましい。
【００２４】
また、二次衝突部材を構成する円錐の底面の半径は、２〜２００ｍｍが好ましく、高さは５〜１００ｍｍが好ましい。また、該円筒の半径は、２〜２００ｍｍが好ましく、高さは５〜２００ｍｍが好ましい。
【００２５】
また、二次衝突部材は、粉砕条件に柔軟に対応でき、所望の粉体材料の粉砕効率を得るために、その高さが調節可能であることが好ましい。該高さを調整する方法としては、例えば、図５に示すように、二次衝突部材を構成する円筒を分割可能に、互いに嵌め込むことができるように構成したり、図６に示すように、分割可能に構成してボルト１１で固定することが挙げられる。但し、本発明は、このような方法に限定するものではない。
【００２６】
本発明において、二次衝突部材を設ける位置は、水平方向は粉砕室４のほぼ中央、垂直方向は、粉砕ノズル５から噴射される圧縮空気どうしが一次衝突する位置１３を基準として、ノズル出口径以上離れたところに設置されていることが好ましい。具体的には、衝突部材を構成する円錐の頂点が、粉砕ノズルから噴射される圧縮空気どうしが一次衝突する位置１３の１０〜５００ｍｍ真上及び／又は真下方に位置するように、二次衝突部材を設けることが好ましく、１０〜３００ｍｍ真上及び／又は真下方にに設けることがより好ましく、１０〜２００ｍｍ真上及び／又は真下方に位置するように設けることが更に好ましい。
【００２７】
本発明においては、二次衝突部材が着脱可能であることが、粉体材料の処理量、平均粒径等の条件変更に対して容易に対応でき、切り替え時間の短縮化も図れるので好ましい。二次衝突部材が着脱可能とするための脱着機構としては、図５、図６に示すように、ネジ止め８、９等が挙げられる。
【００２８】
又、該二次衝突部材は耐摩耗処理を施されていることが、その摩耗を防止し連続粉砕時に所望の粉体材料の粉砕効率を達成することができるので好ましい。耐摩耗処理としては、例えばチタンによるライニング処理を施すことが挙げられる。
【００２９】
次に、本発明の粉砕方法に図面に基づいて説明する。本発明方法は、例えば前述した図１に示す態様の粉砕装置を用いることにより、好ましく実施することができる。
本発明方法においては、まず複数の粉砕ノズル５から圧縮空気を噴射し、該圧縮空気どうしを粉体材料を伴わせて粉砕室４の中で一次衝突させて、該粉体材料を粉砕する。本発明においては、この一次衝突により粉砕された粉体材料を圧縮空気と共に二次衝突させる手段が設けられている。該二次衝突させる手段を設けると、粉砕確率が増加するため、粉体材料の粉砕効率を向上させることができる。
【００３０】
本発明方法においては、粉体材料は、供給管１より供給され、粉砕された微粉は排気管２より排出される。排出された粉体材料に相当する量の粉体材料を適宜供給することにより、連続粉砕が可能となる。粉体の供給量は、１〜１０００ｋｇ／ｈｒが好ましく、１０〜５００ｋｇ／ｈｒがより好ましく、５０〜１００ｋｇ／ｈｒが更に好ましい。
【００３１】
本発明における上記二次衝突手段は、図１に示すように、粉砕ノズルから噴射される圧縮空気どうしを粉体材料を伴わせて一次衝突させる位置１３の上方及び／又は下方に設けられた衝突部材６、７に、該一次衝突した圧縮空気及び粉体材料が二次衝突する手段であることが好ましい。かかる二次衝突部材が設けられていると、粉砕確率が確実に増加するため、粉体材料の粉砕効率を確実に向上させることができる。
【００３２】
上記衝突部材は、図１に示すように、一次衝突する位置１３の下方に設けてもよく（第一衝突部材６）、図２に示すように、一次衝突する位置１３の上方に設けてもよく（第二衝突部材７）、図３に示すように、一次衝突する位置１３の上方と下方の双方に設けてもよい。
【００３３】
本発明方法における二次衝突部材は、特にその形状に制限はないが、衝突板に確実に粉体材料が衝突するような形状および、寸法が必要であり、衝突板の後流も考慮する必要がある。かかる観点から、該二次衝突部材は、図５、図６に示すように、円筒と円錐からなり、該円錐がその底面を円筒の一方の底面に接するように設けられた形状であることが好ましく、該円錐の頂点が一次衝突する位置１３を向くように設けることが好ましい。
【００３４】
また、上記二次衝突部材は、粉砕条件に柔軟に対応でき、所望の粉体材料の粉砕効率を得るために、その高さが５〜５００ｍｍの範囲で調節可能であることが好ましい。
【００３５】
本発明本発明方法において、二次衝突部材を設ける位置は、水平方向は粉砕室４のほぼ中央、垂直方向は、粉砕ノズル５から噴射される圧縮空気どうしが一次衝突する位置１３を基準として、ノズル出口径以上離れたところに設置されていることが好ましい。具体的には、衝突部材を構成する円錐の頂点が、粉砕ノズルから噴射される圧縮空気どうしが一次衝突する位置１３の１０〜５００ｍｍ真上及び／又は真下方に位置するように、二次衝突部材を設けることが好ましく、１０〜３００ｍｍ真上及び／又は真下方にに設けることがより好ましく、１０〜２００ｍｍ真上及び／又は真下方に位置するように設けることが更に好ましい。
【００３６】
本発明方法においては、上記粉砕ノズル５の出口方向は、水平方向を基準にして上下２０°以内を向いていることが好ましく、上下１５°以内を向いていることがより好ましく、上下１０°以内を向いていることが更に好ましく、０°（水平方向）を向いていることが特に好ましい。該方向が、上下２０°を超えると、粉砕効率が悪くなる虞がある。
【００３７】
本発明方法においては、粉砕ノズルに供給する圧縮空気の元圧力は０．２〜１．０ＭＰａに設定することが好ましい。元圧力がかかる範囲内であれば、所望する粉砕効率が得られるが、該元圧力が０．２ＭＰａ未満の場合は、圧縮空気の圧力が低すぎて、粉体材料を伴って粉砕できない虞がある。一方、１．０ＭＰａを超える場合は、粉体材料が所望の粒子径よりも小さい割合が多くなるという過粉砕状態になることや、粉砕ノズル内部の流れに衝撃波が発生し、速度ロスを生じる場合がある。
【００３８】
本発明方法においては、前記二次衝突させた粉体材料を回転するロータに流入させて、微粉と粗粉とに遠心分級することが好ましく、該ロータ３は、図１に示すように、粉砕室４の上部に設けられていることが、粉砕された微粉と粗粉を粉砕室から直接ロータ３内部に流入させて微粉と粗粉とに遠心分級することができるので、より好ましい。
【００３９】
二次衝突させた粉体材料を回転するロータに流入させるには、排気管２と連通する吸引ファン等の吸引器（図示せず）により吸引すればよい。このようにすると、粉砕された粉体材料は、排気管２に向かう途中で、粉砕室４上部に設置されているロータ３内に流入するので、回転するロータ３により粉体材料を分級することができる。このとき、所望の粒径に粉砕された粉体材料は排気管２より排出されるが、所望の粒径よりも大きな粉体材料はロータ３の遠心力によってロータ３の外側に導かれ粉砕室４の壁面を沿って下方に導かれ、再び粉砕作用を受ける。
【００４０】
上記ロータの回転周速度は、２０〜７０ｍ／ｓが好ましい。該回転周速度がかかる範囲内であれば、所望する分級効率を得られるが、２０ｍ／ｓであれば分級効率が低下する虞がある。一方、７０ｍ／ｓを越える場合は、ロータによる遠心力が大きくなりすぎ、吸引ファン等の吸引器により回収されるべき粉体材料が再び粉砕室に戻り、粉砕作用を受けることとなり、粉体材料が所望の粒子径よりも小さい割合が多くなるという過粉砕状態になる虞がある。
【００４１】
【実施例】
次に、本実施例に基づき本発明を詳細に説明する。
本実施例においては、スチレンーアクリル共重合体樹脂８５重量部とカーボンブラック１５重量部の混合物を溶融混練、冷却し、これをハンマーミルで粗粉砕した粉体材料を、図１に示す態様の粉砕装置を用いて粉砕を行った。
【００４２】
（実施例１）
図１に示す態様の、粉砕室内径６００ｍｍ、粉砕装置高さ約１０００ｍｍ、粉砕ノズル出口径１５．０ｍｍの３個の粉砕ノズル５が粉砕室４の壁に沿って、等間隔（当角度）で、粉砕ノズルの出口方向が、水平方向を基準にして０°（水平方向）を向くように設けられた粉砕装置を用いた。また、一次衝突する位置１３は、粉砕室のほぼ中心軸上となるように粉砕ノズル５を取り付けた。
【００４３】
第一次衝突板６の位置を粉砕ノズル５の中心線どうしが交わる位置（即ち、圧縮空気どうしが粉体材料を伴って一次衝突する位置１３）よりも６０ｍｍ真下に設置し、上記組成の粉体材料を供給し、粉砕ノズルに供給する圧縮空気の元圧力０．６ＭＰａ、ロータ３の回転周速度を４５ｍ／ｓに設定して、粉体材料を粉砕した。得られた微粉体は、体積平均粒径６．５μｍ（コールターカウンタによる測定）、４μｍ以下の微粉含有率（個数％）４９％、１６μｍ以上の粗粉含有率（重量％）１．０％であり、粉砕処理量は６０Ｋｇ／ｈｒであった。
【００４４】
（実施例２）
実施例１と同様の粉砕装置を用い、図２に示すように、粉砕ノズル５の中心線どうしが交わる位置よりも６０ｍｍ真上に第二衝突板７を設置した。上記組成の粉体材料を供給し、圧縮空気の元圧力０．６ＭＰａ、ロータ３の回転周速度を４５ｍ／ｓに設定し、他は実施例１と同条件で粉体材料を粉砕した。得られた微粉体は、体積平均粒径６．５μｍ（コールターカウンタによる測定）、４μｍ以下の微粉含有率（個数％）５０％、１６μｍ以上の粗粉含有率（重量％）１．１％であり、粉砕処理量は６２Ｋｇ／ｈｒであった。
【００４５】
（実施例３）
実施例１と同様の粉砕装置を用い、図３に示すように、粉砕ノズル５の中心線どうしが交わる位置より６０ｍｍ真下に第一次衝突板６を設置し、６０ｍｍ真上上に第二次衝突板７を設置した。上記組成の粉体材料を供給し、圧縮空気の元圧力０．６ＭＰａ、ロータ３の回転周速度を４５ｍ／ｓに設定し、他は実施例１と同条件で粉体材料を粉砕した。得られた微粉体は、体積平均粒径６．５μｍ（コールターカウンタによる測定）、４μｍ以下の微粉含有率（個数％）４５％、１６μｍ以上の粗粉含有率（重量％）０．７％であり、粉砕処理量は６４Ｋｇ／ｈｒであった。
【００４６】
（実施例４）
第一衝突板６を脱着可能とした以外は、実施例１と同様に粉体材料を粉砕してから、清掃切替を実施した。その結果、清掃切替時間について、実施例１に比べ約１０％の短縮が可能となった。
【００４７】
（実施例５）
第二衝突板７を脱着可能とした以外は、実施例２と同様に粉体材料を粉砕してから、清掃切替を実施した。その結果、清掃切替時間について、実施例２に比べ約１０％の短縮が可能となった。
【００４８】
（実施例６）
チタンによりライニング処理を施した第一衝突板６を設置した以外は、実施例１と同様に粉体材料を粉砕した結果、摩耗耐久性が従来よりも概ね２倍向上した。
【００４９】
（実施例７）
チタンによりライニング処理を施した第二衝突板７を設置した以外は、実施例２と同様に粉体材料を粉砕した結果、摩耗耐久性が従来よりも概ね２倍向上した。
【００５０】
（比較例１）
第一衝突板６を設置しない以外は、実施例１と同様の装置を用い、圧縮空気の元圧力０．６ＭＰａ、ロータ３の回転周速度４５ｍ／ｓに設定し、実施例１と同様に粉体材料を粉砕した。得られた微粉体は、体積平均粒径６．５μｍ（コールターカウンタによる測定）、４μｍ以下の微粉含有率（個数％）５２％、１６μｍ以上の粗粉含有率（重量％）１．２％であり、粉砕処理量は５５Ｋｇ／ｈｒであった。
【００５１】
なお、本発明は上記実施例に限定されるものではなく、特許請求の範囲内の記載であれば多種の変形や置換可能であることは言うまでもない。
【００５２】
【発明の効果】
以上説明したように、本発明の粉砕装置は、複数の粉砕ノズルと、該粉砕ノズルから噴射される圧縮空気によって供給された粉体材料を粉砕する粉砕室と、回転するロータとを少なくとも有し、該粉砕室から該ロータ内部に流入する粉体材料を微粉と粗粉とに遠心分級する、粉砕装置であり、該複数の粉砕ノズルから噴射される圧縮空気どうしが粉体材料を伴って一次衝突するように各粉砕ノズルを設け、該一次衝突した圧縮空気及び粉体材料が二次衝突する二次衝突手段を設けたので、粉砕装置の粉砕室内での衝突粉砕効率向上を達成し、必要とする大きさの範囲の粒子を高効率で粉砕することができる。
【００５３】
上記二次衝突手段が、円筒と円錐を組み合わせた形状からなり、該円錐がその底面を円筒の一方の底面に接するように設けられた形状の衝突部材を、粉砕ノズルから噴射される圧縮空気どうしが粉体材料を伴って一次衝突する位置の上方及び／又は下方に設ける手段である場合、衝突板に確実に粉体材料が衝突し、衝突板の後流も好ましいものとなるので、衝突粉砕効率がより向上する。
【００５４】
上記衝突部材を着脱可能にすることにより、粉体材料の処理量、平均粒径等の条件変更に対して容易に対応でき、切り替え時間の短縮化も図れる。
【００５５】
また、衝突部材の高さを粉砕条件に応じて調節することにより、粉砕条件に柔軟に対応でき、所望の粉体材料の粉砕効率を得ることができる。
【００５６】
更に、衝突部材に耐摩耗処理を施すことにより、連続粉砕時における二次衝突手段の摩耗を防止でき、所望の粉体材料の粉砕効率を向上できる。
【図面の簡単な説明】
【図１】本発明の粉砕装置の一例を示す断面図である。
【図２】本発明の粉砕装置の他の一例を示す断面図である。
【図３】本発明の粉砕装置の他の一例を示す断面図である。
【図４】従来の粉砕装置の構成を示す断面図である。
【図５】本発明の衝突部材の一例を示す部分断面図である。
【図６】本発明の衝突部材の他の一例を示す部分断面図である。
【符号の説明】
１：供給管
２：排気管
３：ロータ
４：粉砕室
５：粉砕ノズル
６：第一衝突板
７：第二衝突板
８：第一衝突板脱着機構
９：第二衝突板脱着機構
１０：第一衝突板位置調節機構
１１：第二衝突板位置調節機構
１２：ノズル中心線
１３：粉砕ノズルから噴射される圧縮空気どうしが一次衝突する位置[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a pulverizing apparatus and a pulverizing method for a dry toner for developing an electrostatic image in electrophotography, electrostatic recording, electrostatic printing, and the like, and particularly to a fluidized bed pulverizing apparatus and a pulverizing method.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a fluidized-bed pulverizing apparatus for producing a powder material on the order of microns includes a plurality of pulverizing nozzles, a pulverizing chamber, and a rotor rotating above the pulverizing chamber. In such a fluidized bed pulverizer, the supplied powder material is accelerated by compressed air injected from a plurality of pulverizing nozzles, and the powder materials collide with each other and undergo a pulverizing action. The powder material having a desired particle size or less is collected inside the rotor, and the powder material having a desired particle size or more is guided to the outside of the rotor. It returns to the grinding chamber and receives the grinding action.
[0003]
The configuration and operation of the conventional fluidized bed pulverizer will be described in detail with reference to FIG.
FIG. 4 is a cross-sectional view of a conventional fluidized bed pulverizer. In FIG. 4, reference numeral 1 denotes a supply pipe through which the powder material is supplied, and 2 denotes an exhaust pipe through which the pulverized powder material is discharged together with air. Reference numeral 3 denotes a rotor for classifying the pulverized powder material, reference numeral 4 denotes a pulverizing chamber, and reference numeral 5 denotes a pulverizing nozzle for conveying compressed air sent into the pulverizing chamber 4. In addition, the whole crushing apparatus main body consists of a substantially cylindrical housing.
[0004]
In the conventional pulverizing apparatus shown in FIG. 4, first, a certain amount of powder material is filled in the pulverizing chamber 4, and then compressed air is conveyed from the pulverizing nozzle 5 and supplied from the opposing pulverizing nozzle 5. The crushed air collides near the intersection of the exit extension lines of the opposing crushing nozzles 5, that is, near the central axis of the crushing chamber 4. At this time, the powder material guided and accelerated by the air also collides near the central axis of the crushing chamber 4 and receives a crushing action. On the other hand, when suction is performed by a suction device (not shown) such as a suction fan communicating with the exhaust pipe 2, the pulverized powder material is directed to the exhaust pipe 2. At this time, since the rotor 3 installed in the upper part of the pulverizing chamber 4 is rotating, the powder material pulverized to a desired particle size is discharged from the exhaust pipe 2, but the powder material larger than the desired particle size is discharged. The body material is guided to the outside of the rotor 3 by the centrifugal force of the rotor 3 and is guided downward along the wall surface of the crushing chamber 4 to be subjected to the crushing action again. Further, since the powder material crushed to a desired particle size is discharged from the exhaust pipe 2, the amount of the powder material in the crushing chamber 4 is reduced. If the amount of the powder material in the crushing chamber 4 is always set to be constant, continuous crushing is performed.
[0005]
Thus, continuous pulverization is possible in the conventional fluidized bed pulverizer.
However, in a conventional fluidized-bed pulverizer, repeated pulverization in a pulverization chamber is required to obtain a desired particle size, which is one of the causes of lowering pulverization efficiency.
[0006]
As an apparatus for improving the pulverizing efficiency, for example, there is JP-A-2000-005621 (Patent Document 1). In Patent Literature 1, a collision member is installed such that the center thereof is located on the center axis of the grinding chamber, and a high-speed gas including the material to be crushed is vertically injected to the member, and the material to be crushed is It is disclosed that the material is pulverized by colliding with a collision member to efficiently obtain a pulverized product having a desired particle size.
[0007]
However, in the fluidized bed pulverizer disclosed in Patent Document 1, when the high-speed gas injected from the nozzle and the object to be pulverized in the pulverization chamber collide with the collision member, the pulverization nozzle pressure must be increased. There is a problem that must be. This is because, in a conventional fluidized bed pulverizer as shown in FIG. 4, since high-speed gas is injected from an opposed nozzle, powder materials collide with the high-speed gas at an accelerated relative speed and pulverize. On the other hand, in the apparatus disclosed in Patent Document 1, the relative speed between the powder materials is not accelerated together with the high-speed gas. Therefore, in order to obtain the same pulverizing effect as the apparatus shown in FIG. This is because it is necessary to raise the nozzle pressure and cause the crushed object to collide with the collision member at a higher speed. Although the object to be crushed collides with the collision member by the high-speed gas injected from the nozzle, repeated pulverization in the pulverization chamber is necessary to obtain a desired particle size, which is one of the causes of a reduction in pulverization efficiency. It is one.
[0008]
Further, in accordance with recent demand for higher image quality, it is desired that the crushing apparatus has a shorter type switching time than a conventional apparatus in order to cope with a small particle size and a small number of varieties.
[0009]
[Patent Document 1]
JP 2000-005621 A
[0010]
[Problems to be solved by the invention]
The present invention has been made to solve these problems, and achieves improved collision crushing efficiency in a crushing chamber of a crusher, and can crush particles in a required size range with high efficiency. A first object is to provide a crushing apparatus, and a second object is to reduce the time required to switch types.
[0011]
[Means for Solving the Problems]
According to the present invention, a crushing device and a crushing method described below are provided.
[1] At least a plurality of pulverizing nozzles, a pulverizing chamber for pulverizing the powder material supplied by the compressed air injected from the pulverizing nozzle, and a rotating rotor, which flow into the rotor from the pulverizing chamber In a pulverizer, the powder material to be centrifugally classified into fine powder and coarse powder is provided.Each of the pulverization nozzles is provided so that compressed air injected from the plurality of pulverization nozzles primarily collide with the powder material. A pulverizing device comprising a secondary collision means for performing a secondary collision of compressed air and powder material which have primary collision.
[2] The secondary collision means applies the compressed air that has primarily collided to a collision member provided above and / or below a position where the compressed air injected from the pulverizing nozzles primarily collide with the powder material. And a means for secondary collision of the powder material with the powder material.
[3] The collision member according to [2], wherein the collision member has a shape in which a cylinder and a cone are combined, and the cone has a shape provided such that a bottom surface thereof is in contact with one bottom surface of the cylinder. Crushing equipment.
[4] so that the apex of the cone that constitutes the collision member is located 10 to 500 mm directly above and / or below the position where the compressed air injected from the pulverizing nozzles primarily collide with the powder material, The crusher according to the above [3], further comprising a secondary collision member.
[5] The crusher according to any one of [2] to [4], wherein the height of the collision member is adjustable.
[6] The crusher according to any one of [2] to [5], wherein the secondary collision member is detachable.
[7] The crushing device according to any one of [2] to [6], wherein the secondary collision member is subjected to a wear resistance treatment.
[8] The crusher according to any one of [1] to [7], wherein 2 to 8 crushing nozzles are provided.
[9] The grinding according to any one of [1] to [8], wherein the grinding nozzles are provided at equal intervals on a concentric circle centered on a longitudinal central axis of the grinding chamber. apparatus.
[10] The crushing device according to any one of [1] to [9], wherein an outlet direction of the crushing nozzle is oriented within 20 ° vertically with respect to a horizontal direction.
[11] In the pulverization method of injecting compressed air from a plurality of pulverizing nozzles and causing the compressed air to collide with the powder material in a pulverizing chamber to pulverize the powder material, Characterized by providing a means for secondary collision of compressed air and powder material.
[12] The secondary collision means presses the compressed air which has been subjected to the primary collision with a collision member provided above and / or below a position where the compressed air injected from the pulverizing nozzle is primarily collided with the powder material. The pulverization method according to the above [11], wherein the pulverization method is a means for performing a secondary collision of air and a powder material.
[13] The crushing method according to [12], wherein the collision member comprises a cylinder and a cone, and the cone has a shape provided such that a bottom surface thereof is in contact with one bottom surface of the cylinder.
[14] Providing the collision member such that the apex of the cone constituting the collision member is located 10 to 500 mm directly above and / or directly below the position where the compressed air injected from the pulverizing nozzles primarily collide with each other. The pulverization method according to the above [13], which is characterized in that:
[15] The crushing method according to any one of [12] to [14], wherein the position of the vertex of the cone constituting the collision member is moved up and down in accordance with crushing conditions.
[16] The outlet direction of each of the plurality of crushing nozzles is set so as to face within 20 ° vertically with respect to a horizontal direction, and the compressed air is injected from the plurality of crushing nozzles. [11] The pulverization method according to any one of [15] to [15].
[17] The grinding method according to any one of [11] to [16], wherein the original pressure of the compressed air supplied to the grinding nozzle is set to 0.2 to 1.0 MPa.
[18] The powder according to any one of [11] to [17], wherein the powder material subjected to the secondary collision is caused to flow into a rotating rotor and centrifugally classified into fine powder and coarse powder. Grinding method.
[19] The pulverization method according to [18], wherein the rotational peripheral speed of the rotor is 20 to 70 m / s.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the pulverizing apparatus and the pulverizing method of the present invention will be described in detail with reference to the drawings. First, the crushing device of the present invention will be described.
The pulverizing device of the present invention has at least a plurality of pulverizing nozzles, a pulverizing chamber for pulverizing a powder material supplied by compressed air injected from the pulverizing nozzles, and a rotating rotor. Since the crushing device of the present invention is configured as described above, the crushed material can be crushed into fine powder and coarse powder in the crushing chamber, and the crushed fine powder and coarse powder can be centrifugally classified by a rotating rotor.
[0013]
FIG. 1 shows a preferred example of the pulverizing apparatus of the present invention. FIG. 1 is a sectional view showing an example of the pulverizing device of the present invention. However, FIG. 1 does not limit the present invention.
The pulverizing apparatus of the embodiment shown in FIG. 1 includes a plurality of pulverizing nozzles 5, a pulverizing chamber 4 for pulverizing a powder material supplied by compressed air injected from the pulverizing nozzle 5, and a rotating rotor 3. In the present invention, as shown in FIG. 1, it is preferable that the rotor 3 is provided above the pulverizing chamber 4. When the rotor 3 is provided in the upper part of the pulverizing chamber 4, the pulverized fine powder and coarse powder can flow directly into the rotor 3 from the pulverizing chamber 4 and classified into fine powder and coarse powder by centrifugation.
[0014]
Although the shape of the crushing chamber 4 is not limited, a cylindrical shape is usually preferable from the viewpoint that the powder material can be uniformly supplied and crushed uniformly. Also, the size of the crushing chamber 4 is not limited, but from the viewpoint that a large amount of powdered material can be efficiently crushed, the inner diameter is preferably 100 to 1000 mm and the height is 300 to 3000 mm, and the inner diameter is 300 to 900 mm. 700 to 2700 mm is more preferable, the inner diameter is 500 to 800 mm, and the height is 1000 to 2500 mm.
[0015]
In the pulverizing device of the present invention, the plurality of pulverizing nozzles 5 are provided such that the compressed air injected from the pulverizing nozzles 5 primarily collide with the powder material. Due to this primary collision, the supplied powder material undergoes the first crushing action.
[0016]
Although the number of the crushing nozzles 5 is not limited, it is preferable to use 2 to 8 crushing nozzles, more preferably to use 2 to 6 crushing nozzles, and more preferably to use 3 to 4 crushing nozzles. preferable. With a single grinding nozzle, compressed air cannot be primarily impinged with powdered material. On the other hand, if the number of the crushing nozzles 5 is too large, the production of the apparatus becomes complicated, and the crushing efficiency may be rather reduced.
[0017]
The crushing nozzle 5 is preferably provided on a concentric circle centered on the longitudinal center axis of the crushing chamber so that the compressed air to be injected collides on the center axis of the crushing chamber. It is preferable to provide the concentric circles at equal intervals (equivalent angles) so as to collide with each other. However, in the present specification, the term “collision of compressed air on the central axis of the pulverizing chamber” means a collision near the central axis of the pulverizing chamber.
[0018]
The outlet direction of the pulverizing nozzle 5 is preferably oriented within 20 ° vertically with respect to the horizontal direction, more preferably oriented within 15 ° vertically, and more preferably oriented within 10 ° vertically. It is particularly preferable to be oriented at 0 ° (horizontal direction). If the direction exceeds 20 ° vertically, the crushing efficiency may be deteriorated.
[0019]
In the pulverizing device of the present invention, a secondary collision means for performing the secondary collision of the compressed air and the powder material which have been subjected to the primary collision is provided. When the powder material after the primary collision is further collided by the secondary collision means, the probability of pulverization increases, so that the pulverization efficiency in the pulverization chamber can be improved.
[0020]
The secondary collision means in the present invention is a collision member provided above and / or below a position 13 (shown in FIG. 1) where compressed air injected from the pulverizing nozzles 5 primarily collide with powdered material. In addition, it is preferable that the compressed air and the powder material, which have been subjected to the primary collision, be subjected to secondary collision. By providing such a secondary collision member, when the powder material is subjected to secondary collision, the probability of pulverization is surely increased, so that the pulverization efficiency in the pulverization chamber can be reliably improved.
[0021]
In the present invention, the position 13 at which the compressed air injected from the crushing nozzles 5 primarily collides with the powder material is determined by the position where the center lines 12 of the crushing nozzles 5 intersect.
[0022]
The collision member may be provided below the primary collision position 13 as shown in FIG. 1, or may be provided above the primary collision position 13 as shown in FIG. Alternatively, it may be provided both above and below the primary collision position 13.
Hereinafter, the secondary collision member provided below is referred to as a first collision member 6, and the secondary collision member provided above is referred to as a second collision member 7.
[0023]
The secondary collision member in the present invention is not particularly limited in its shape, but must have a shape and dimensions so that the powder material surely collides with the collision plate, and also need to consider the wake of the collision plate. is there. From this viewpoint, as shown in FIGS. 5 and 6, the secondary collision member may have a shape in which a cylinder and a cone are provided, and the cone is provided so that its bottom surface is in contact with one bottom surface of the cylinder. It is preferable that the apex of the cone be provided so as to face the primary collision position 13.
[0024]
Further, the radius of the bottom surface of the cone constituting the secondary collision member is preferably 2 to 200 mm, and the height is preferably 5 to 100 mm. The radius of the cylinder is preferably 2 to 200 mm, and the height is preferably 5 to 200 mm.
[0025]
Further, it is preferable that the height of the secondary collision member can be adjusted flexibly so as to be able to flexibly cope with the pulverization conditions and to obtain the desired pulverization efficiency of the powder material. As a method of adjusting the height, for example, as shown in FIG. 5, a cylinder constituting a secondary collision member can be divided so as to be fitted into each other, or as shown in FIG. , And fixed by bolts 11. However, the present invention is not limited to such a method.
[0026]
In the present invention, the position at which the secondary collision member is provided is substantially the center of the crushing chamber 4 in the horizontal direction, and the nozzle outlet diameter is determined in the vertical direction with respect to the position 13 at which the compressed air injected from the crushing nozzle 5 primarily collides. It is preferable that it is installed at a distance as described above. Specifically, the secondary collision is performed such that the apex of the cone constituting the collision member is located 10 to 500 mm directly above and / or below the position 13 where the compressed air injected from the pulverizing nozzles primarily collide with each other. The member is preferably provided, more preferably provided directly above and / or below 10 to 300 mm, and even more preferably provided directly above and / or below 10 to 200 mm.
[0027]
In the present invention, it is preferable that the secondary collision member be detachable since it can easily cope with a change in the conditions such as the processing amount of the powder material and the average particle diameter, and the switching time can be shortened. As the attachment / detachment mechanism for making the secondary collision member detachable, as shown in FIGS. 5 and 6, screwing 8, 9 and the like can be mentioned.
[0028]
Further, it is preferable that the secondary collision member is subjected to a wear-resistant treatment, because the wear can be prevented and a desired powder material crushing efficiency can be achieved at the time of continuous crushing. As the wear-resistant treatment, for example, a lining treatment with titanium can be given.
[0029]
Next, the pulverizing method of the present invention will be described with reference to the drawings. The method of the present invention can be preferably carried out, for example, by using the pulverizing apparatus of the embodiment shown in FIG.
In the method of the present invention, compressed air is first injected from a plurality of pulverizing nozzles 5, and the compressed air is primarily collided with the powdered material in the pulverizing chamber 4 to pulverize the powdered material. In the present invention, a means is provided for causing the powder material pulverized by the primary collision to undergo secondary collision with compressed air. Providing the secondary collision means increases the probability of crushing, so that the efficiency of crushing the powder material can be improved.
[0030]
In the method of the present invention, the powder material is supplied from a supply pipe 1 and the pulverized fine powder is discharged from an exhaust pipe 2. By appropriately supplying an amount of powder material corresponding to the discharged powder material, continuous pulverization becomes possible. The supply amount of the powder is preferably 1 to 1000 kg / hr, more preferably 10 to 500 kg / hr, and still more preferably 50 to 100 kg / hr.
[0031]
As shown in FIG. 1, the secondary collision means according to the present invention includes a collision provided above and / or below a position 13 in which compressed air injected from a pulverizing nozzle is primarily collided with a powder material. It is preferable that the compressed air and the powder material that have primarily collided with the members 6 and 7 are secondary collision means. If such a secondary collision member is provided, the pulverization probability is surely increased, so that the pulverization efficiency of the powder material can be reliably improved.
[0032]
The collision member may be provided below the primary collision position 13 as shown in FIG. 1 (first collision member 6), or may be provided above the primary collision position 13 as shown in FIG. Often, the second collision member 7 may be provided both above and below the primary collision position 13 as shown in FIG.
[0033]
The secondary collision member in the method of the present invention is not particularly limited in its shape, but the secondary collision member needs to have a shape and dimensions such that the powder material surely collides against the collision plate, and also consider the wake of the collision plate. There is. From this viewpoint, as shown in FIGS. 5 and 6, the secondary collision member may have a shape in which a cylinder and a cone are provided, and the cone is provided so that its bottom surface is in contact with one bottom surface of the cylinder. Preferably, the apex of the cone is provided so as to face the primary collision position 13.
[0034]
In addition, it is preferable that the height of the secondary collision member can be adjusted in a range of 5 to 500 mm so that the secondary collision member can flexibly cope with pulverization conditions and obtain a desired pulverization efficiency of the powder material.
[0035]
In the method of the present invention, the position at which the secondary collision member is provided is substantially the center of the crushing chamber 4 in the horizontal direction, and the position 13 at which the compressed air injected from the crushing nozzle 5 primarily collides with each other in the horizontal direction. It is preferable to be installed at a position apart from the nozzle outlet diameter. Specifically, the secondary collision is performed such that the apex of the cone constituting the collision member is located 10 to 500 mm directly above and / or below the position 13 where the compressed air injected from the pulverizing nozzles primarily collide with each other. The member is preferably provided, more preferably provided directly above and / or below 10 to 300 mm, and even more preferably provided directly above and / or below 10 to 200 mm.
[0036]
In the method of the present invention, the outlet direction of the pulverizing nozzle 5 is preferably oriented within 20 ° vertically with respect to the horizontal direction, more preferably oriented within 15 ° vertically, and within 10 ° vertically. More preferably, and particularly preferably 0 ° (horizontal direction). If the direction exceeds 20 ° vertically, the crushing efficiency may be deteriorated.
[0037]
In the method of the present invention, the original pressure of the compressed air supplied to the pulverizing nozzle is preferably set to 0.2 to 1.0 MPa. If the original pressure is within the range, the desired pulverization efficiency can be obtained, but if the original pressure is less than 0.2 MPa, the pressure of the compressed air is too low, and there is a possibility that the pulverization cannot be performed with the powder material. is there. On the other hand, if the pressure exceeds 1.0 MPa, the powder material may be in an over-pulverized state in which the proportion smaller than the desired particle diameter is increased, or a shock wave may be generated in the flow inside the pulverizing nozzle to cause a speed loss. There is.
[0038]
In the method of the present invention, it is preferable that the powder material subjected to the secondary collision is caused to flow into a rotating rotor and classified into fine powder and coarse powder by centrifugal classification. As shown in FIG. It is more preferable that the fine powder and the coarse powder are provided in the upper part of the chamber 4 because the fine powder and the coarse powder can flow directly into the inside of the rotor 3 from the grinding chamber and are centrifugally classified into the fine powder and the coarse powder.
[0039]
In order to cause the powder material subjected to the secondary collision to flow into the rotating rotor, the powder material may be sucked by a suction device (not shown) such as a suction fan communicating with the exhaust pipe 2. In this way, the pulverized powder material flows into the rotor 3 installed above the pulverization chamber 4 on the way to the exhaust pipe 2, so that the powder material is classified by the rotating rotor 3. Can be. At this time, the powder material pulverized to the desired particle size is discharged from the exhaust pipe 2, but the powder material larger than the desired particle size is guided to the outside of the rotor 3 by centrifugal force of the rotor 3 and is crushed. 4 is guided downward along the wall surface and is again subjected to the pulverizing action.
[0040]
The rotational peripheral speed of the rotor is preferably 20 to 70 m / s. If the rotational peripheral speed is within this range, a desired classification efficiency can be obtained, but if it is 20 m / s, the classification efficiency may be reduced. On the other hand, when the speed exceeds 70 m / s, the centrifugal force of the rotor becomes too large, and the powder material to be recovered by the suction device such as the suction fan returns to the grinding chamber again and receives the grinding action. However, there is a possibility that an excessively pulverized state may occur in which the ratio of particles having a particle size smaller than the desired particle size increases.
[0041]
【Example】
Next, the present invention will be described in detail based on the present embodiment.
In this example, a mixture of 85 parts by weight of a styrene-acrylic copolymer resin and 15 parts by weight of carbon black was melt-kneaded, cooled, and coarsely pulverized with a hammer mill to obtain a powder material having the form shown in FIG. The pulverization was performed using a pulverizer.
[0042]
(Example 1)
In the embodiment shown in FIG. 1, three crushing nozzles 5 having a crushing chamber diameter of 600 mm, a crushing device height of about 1000 mm, and a crushing nozzle outlet diameter of 15.0 mm are formed along the wall of the crushing chamber 4 at equal intervals (at the same angle). A pulverizing device was used in which the outlet direction of the pulverizing nozzle was oriented at 0 ° (horizontal direction) with respect to the horizontal direction. Further, the crushing nozzle 5 was attached so that the position 13 for the primary collision was substantially on the center axis of the crushing chamber.
[0043]
The position of the primary impingement plate 6 is set 60 mm below the position where the center lines of the pulverizing nozzles 5 intersect (that is, the position 13 where the compressed air primarily impinges with the powder material), and the powder having the above composition is placed. The powder material was pulverized by supplying the body material and setting the original pressure of the compressed air supplied to the pulverizing nozzle at 0.6 MPa and the rotational peripheral speed of the rotor 3 at 45 m / s. The obtained fine powder had a volume average particle diameter of 6.5 μm (measured by a Coulter counter), a fine powder content of 4 μm or less (number%) of 49%, and a coarse powder content of 16 μm or more (% by weight) of 1.0%. The pulverization amount was 60 kg / hr.
[0044]
(Example 2)
Using the same crushing apparatus as in Example 1, as shown in FIG. 2, the second impingement plate 7 was installed directly above the position where the center lines of the crushing nozzles 5 intersect with each other by 60 mm. The powder material having the above composition was supplied, and the raw material pressure of the compressed air was set at 0.6 MPa, the rotational peripheral speed of the rotor 3 was set at 45 m / s, and the powder material was ground under the same conditions as in Example 1 except for the above. The obtained fine powder had a volume average particle diameter of 6.5 μm (measured by a Coulter counter), a fine powder content of 4 μm or less (number%) of 50%, and a coarse powder content of 16 μm or more (% by weight) of 1.1%. The pulverization amount was 62 Kg / hr.
[0045]
(Example 3)
As shown in FIG. 3, the primary collision plate 6 was installed 60 mm directly below the position where the center lines of the grinding nozzles 5 intersect, and the secondary collision plate 6 The collision plate 7 was installed. The powder material having the above composition was supplied, and the raw material pressure of the compressed air was set at 0.6 MPa, the rotational peripheral speed of the rotor 3 was set at 45 m / s, and the powder material was ground under the same conditions as in Example 1 except for the above. The obtained fine powder had a volume average particle size of 6.5 μm (measured by a Coulter counter), a fine powder content of 4 μm or less (number%) of 45%, and a coarse powder content of 16 μm or more (% by weight) of 0.7%. The pulverization amount was 64 kg / hr.
[0046]
(Example 4)
Except that the first collision plate 6 was detachable, the cleaning was switched after the powder material was crushed in the same manner as in Example 1. As a result, the cleaning switching time can be reduced by about 10% as compared with the first embodiment.
[0047]
(Example 5)
Except that the second collision plate 7 was made removable, the cleaning was switched after the powder material was crushed in the same manner as in Example 2. As a result, the cleaning switching time can be reduced by about 10% compared to the second embodiment.
[0048]
(Example 6)
Except that the first impact plate 6 lined with titanium was provided, the powder material was pulverized in the same manner as in Example 1, and as a result, the wear durability was almost twice as high as that of the conventional one.
[0049]
(Example 7)
Except for installing the second impact plate 7 lined with titanium, the powder material was crushed in the same manner as in Example 2, and as a result, the wear durability was almost twice as high as that of the conventional one.
[0050]
(Comparative Example 1)
Except that the first impingement plate 6 was not installed, the same apparatus as in Example 1 was used, and the original pressure of the compressed air was set to 0.6 MPa and the rotational peripheral speed of the rotor 3 was set to 45 m / s. The body material was crushed. The obtained fine powder had a volume average particle size of 6.5 μm (measured by a Coulter counter), a fine powder content (number%) of 4 μm or less, 52%, and a coarse powder content (weight%) of 16 μm or more, 1.2%. The pulverization amount was 55 kg / hr.
[0051]
It should be noted that the present invention is not limited to the above embodiment, and it goes without saying that various modifications and substitutions can be made within the scope of the claims.
[0052]
【The invention's effect】
As described above, the pulverizing device of the present invention has at least a plurality of pulverizing nozzles, a pulverizing chamber for pulverizing the powder material supplied by the compressed air injected from the pulverizing nozzle, and a rotating rotor. A pulverizing apparatus for centrifugally classifying a powder material flowing into the rotor from the pulverizing chamber into fine powder and coarse powder, wherein compressed air jetted from the plurality of pulverizing nozzles is primarily mixed with the powder material. Each pulverizing nozzle is provided so as to collide, and secondary collision means is provided for the secondary collision of the compressed air and the powder material which have been primary collided. Can be pulverized with high efficiency.
[0053]
The secondary collision means has a shape in which a cylinder and a cone are combined, and the cone has a shape in which the bottom surface is in contact with one bottom surface of the cylinder. Is a means provided above and / or below the position where the primary collision occurs with the powder material, the powder material surely collides with the collision plate, and the wake of the collision plate also becomes favorable. Efficiency is further improved.
[0054]
By making the collision member detachable, it is possible to easily cope with changes in conditions such as the amount of powder material to be processed and the average particle diameter, and to shorten the switching time.
[0055]
In addition, by adjusting the height of the collision member in accordance with the crushing conditions, it is possible to flexibly respond to the crushing conditions and to obtain a desired crushing efficiency of the powder material.
[0056]
Furthermore, by performing abrasion resistance treatment on the collision member, abrasion of the secondary collision means during continuous grinding can be prevented, and the efficiency of grinding the desired powder material can be improved.
[Brief description of the drawings]
FIG. 1 is a sectional view showing an example of a pulverizing device of the present invention.
FIG. 2 is a sectional view showing another example of the pulverizing device of the present invention.
FIG. 3 is a sectional view showing another example of the pulverizing device of the present invention.
FIG. 4 is a cross-sectional view showing a configuration of a conventional crusher.
FIG. 5 is a partial sectional view showing an example of the collision member of the present invention.
FIG. 6 is a partial sectional view showing another example of the collision member of the present invention.
[Explanation of symbols]
1: Supply pipe
2: Exhaust pipe
3: Rotor
4: crushing room
5: crushing nozzle
6: First collision plate
7: Second collision plate
8: First collision plate attachment / detachment mechanism
9: Second collision plate attachment / detachment mechanism
10: First collision plate position adjustment mechanism
11: second collision plate position adjustment mechanism
12: Nozzle center line
13: Position where compressed air injected from the pulverizing nozzle collide with each other

Claims

A plurality of pulverizing nozzles, a pulverizing chamber for pulverizing a powder material supplied by compressed air injected from the pulverizing nozzle, and a rotating rotor, and powder flowing into the rotor from the pulverizing chamber. In the pulverizer, which classifies the material into fine powder and coarse powder by centrifugation, in a pulverizing apparatus, each pulverizing nozzle is provided so that compressed air injected from the plurality of pulverizing nozzles first collide with the powder material, and the primary collision is performed. A pulverizer comprising a secondary collision means for performing secondary collision of compressed air and a powder material.

The secondary collision means applies the compressed air and the powder that have primarily collided to a collision member provided above and / or below a position where the compressed air injected from the pulverizing nozzles primarily collide with the powder material. The crushing device according to claim 1, wherein the material is a means for secondary collision.

The crushing device according to claim 2, wherein the collision member has a shape obtained by combining a cylinder and a cone, and the cone has a shape provided such that a bottom surface thereof is in contact with one bottom surface of the cylinder.

The secondary collision is performed such that the apex of the cone constituting the collision member is located 10 to 500 mm directly above and / or below the position where the compressed air injected from the pulverizing nozzles primarily collide with the powder material. The crushing device according to claim 3, further comprising a member.

The crushing device according to any one of claims 2 to 4, wherein the height of the collision member is adjustable.

The crushing device according to any one of claims 2 to 5, wherein the secondary collision member is detachable.

The crushing device according to any one of claims 2 to 6, wherein the secondary collision member has been subjected to a wear-resistant treatment.

The crushing device according to any one of claims 1 to 7, wherein 2 to 8 crushing nozzles are provided.

The crushing device according to any one of claims 1 to 8, wherein the crushing nozzles are provided at equal intervals on a concentric circle centered on a longitudinal central axis of the crushing chamber.

The crushing device according to any one of claims 1 to 9, wherein the outlet direction of the crushing nozzle is oriented within 20 ° vertically with respect to the horizontal direction.

In a pulverizing method of injecting compressed air from a plurality of pulverizing nozzles and causing the compressed air to primarily collide with a powder material in a pulverizing chamber to pulverize the powder material into fine powder and coarse powder, A pulverization method, comprising: means for performing a secondary collision between the compressed air and the powder material which have been subjected to the primary collision.

The secondary collision means applies the compressed air and the powder that have primarily collided to a collision member provided above and / or below a position where the compressed air injected from the pulverizing nozzle is primarily collided with the powder material. The pulverizing method according to claim 11, wherein the pulverizing means is a means for causing a secondary collision of the body material.

The grinding method according to claim 12, wherein the collision member comprises a cylinder and a cone, and the cone has a shape provided such that a bottom surface thereof is in contact with one bottom surface of the cylinder.

The collision member is provided such that the apex of the cone constituting the collision member is located directly above and / or below 10 to 500 mm of the position where the compressed air injected from the pulverizing nozzles primarily collide with each other. The pulverization method according to claim 13.

The grinding method according to any one of claims 12 to 14, wherein a position of a vertex of a cone constituting the collision member is moved up and down in accordance with grinding conditions.

The outlet direction of each of the plurality of crushing nozzles is set so as to face within 20 degrees vertically with respect to the horizontal direction, and compressed air is injected from the plurality of crushing nozzles. 15. The pulverization method according to any one of 15).

The grinding method according to any one of claims 11 to 16, wherein the original pressure of the compressed air supplied to the grinding nozzle is set to 0.2 to 1.0 MPa.

The pulverization method according to any one of claims 11 to 17, wherein the powder material that has been subjected to the secondary collision is caused to flow into a rotating rotor, and is subjected to centrifugal classification into fine powder and coarse powder.

The grinding method according to claim 18, wherein the rotation peripheral speed of the rotor is 20 to 70 m / s.