JP3592520B2

JP3592520B2 - Airflow classifier

Info

Publication number: JP3592520B2
Application number: JP11010998A
Authority: JP
Inventors: 賢一上原; 信康牧野; 智行佐藤
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 1998-04-07
Filing date: 1998-04-07
Publication date: 2004-11-24
Anticipated expiration: 2018-04-07
Also published as: JPH11290785A

Description

【０００１】
【発明の属する技術分野】
本発明は、電子写真トナー等の微粒子粉体を所定の粒度に分級するために旋回気流を利用する気流式分級装置に関する。
【０００２】
【従来の技術】
一般に、電子写真トナー等の微粒子粉体を所定の粒度に分級するために旋回気流を利用する気流式分級装置が用いられている。例えば図１５に示すように、この気流式分級装置は、流入口（１１）から一次空気と共に供給される粉体材料（１２）を分散し、排気と共に超微粉を排出する分散室（１３）と、分散室（１３）下方に連続して設けられて、分散室（１３）から流入する粉体材料（１２）を、微粉と粗粉とに遠心分離する分級室（１４）とを有する。最近では分散室（１３）の旋回風速を制御し、また分級室（１４）における分級粒度を変更することが可能な回転ローター（１５）を分散室上部に有している。
【０００３】
しかしながら、このような気流式分級装置（図１５）を稼働するにあたっては、分級室（１４）で微粉側に含まれて排出される粗粉の他に、流入口（１１）から分散室（１３）に流入する粉体材料（１２）の流速と、分級室（１２）内部に定常的に発生している旋回風速が異なるため、質量差より粉体材料（１２）の加速状態の格差が発生して、乱流領域、強度の拡大から遠心力のバラツキが多くなり、超微粉と共に排出される粗粉も多くなる。
【０００４】
また、分散室（１３）からの排出粗粉を減少する操作を行なうことで、分散室（１３）の機能とする超微粉の排出も減少するため、分級室（１４）の超微粉割合が増し、超微粉の持つファンデルワールス力により、凝集の影響が受けやすくなり、分級装置を有する生産工程での製品歩留まりの低下を招いている。
【０００５】
【発明が解決しようとする課題】
本発明は、上記のような問題点を改善するべくなされたもので、その目的は、分散室から排出される粉体材料中の粗粉を減少させ、かつ分級室に流入する超微粉を削減することのできる気流式分級装置を提供することにある。
【０００６】
【課題を解決するための手段】
上記目的は、本発明の（１）「搬送空気と共に供給される粉体材料を分散し、超微粉を分離廃棄する回転式ローターを有し、分散する分散室と、該分散室の下方に連続して該分散室から流入する粉体材料を微粉と粗粉とに遠心分級する分級室を有する気流式分級装置において、前記分散室内のローターより排気される空気量をＱ１、分散室に流入する空気量をＱ２としたとき、下記式（１）で示される関係式を満足する設定、もしくは構造を形成されることを特徴とする気流式分級装置。
【０００７】
【数４】

」、（２）「前記分級装置の分散室に粉体材料が流入する流入口が分散室壁面に沿い、接線方向に位置し、分散室に接する法線方向寸法をＷ、流入する分散内径をＤ、ローター径をｄとした（Ｗ、Ｄ、ｄはｍｍで表わした値）とき下記式（３）で示される関係式を満足する構造を特徴とする前記第（１）項に記載の気流式分級装置。
【０００８】
【数５】

」、（３）「前記分級装置の分散室に粉体材料が流入する流入口法線方向寸法Ｗが、該流入口に設けられた可変式邪魔板により任意に変更可能な構造であることを特徴とする前記第（１）項に記載の気流式分級装置。」、（４）「前記分級装置の分散室に粉体材料が流入する流入口法線方向寸法Ｗが、ローター回転数の変動等に応じ、自動で流入口法線方向寸法Ｗを形成する機構を有することを特徴とする前記第（１）項に記載の気流式分級装置。」、（５）「前記分級装置の流入口より分散室内部に、流入方向に対して垂直もしくは流入方向に対して若干の角度傾いて配置されたガイドベーンを単枚もしくは複数枚有することを特徴とする前記第（１）項に記載の気流式分級装置。」、（６）「前記分級装置の分散室に粉体材料供給する供給配管内部に粉体材料を加速させる機能を設けることを特徴とする前記第（１）項に記載の気流式分級装置。」、（７）「前記分級装置の分散室に粉体材料が流入する流入口部に、開口面積を変更可能な邪魔板を有することを特徴とする前記第（１）項に記載の気流式分級装置。」、（８）「前記分級装置のローター回転数等に応じ、供給配管内部に設けた粉体材料加速器、または流入口部に設けた邪魔板の位置設定を単独、あるいは同時に自動で制御する機能を有することを特徴とする前記第（１）項に記載の気流式分級装置。」、（９）「前記分散室内のローター位置を粉体材料が流入する流入口下部よりローター上面までの距離をＨ、分散室内径をＤ、ローター径をｄとし（Ｈ、Ｄ、ｄはｍｍ単位で表わした値）たとき、下記式（４）で示される関係式を満足する構造であることを特徴とする請求項１に記載の気流式分級装置。
【０００９】
【数６】

」、（１０）「前記分級装置の分散室に粉体材料が流入する流入口の高さ寸法Ｙにおける分散室内壁面の一部が、ローター高さ位置の分散室内径より大きく、分散室の流入口位置の内壁とその下の位置の内壁との間に段差をもつ構造が形成されたことを特徴とする前記第（１）項に記載の気流式分級装置。」、（１１）「前記分級装置の分散室に粉体材料が流入する流入口下部とローター部の間内にて、内壁面の少なくとも一部に邪魔板を円周方向に設けた構造が形成されたことを特徴とする前記第（１）項に記載の気流式分級装置。」により達成される。
【００１０】
【発明の実施の形態】
以下、本発明を図によって詳細に説明する。
【００１１】
前記第（１）項記載の気流式分級装置についてその構成を図１に示す。
分散室（１０３）上部には、回転ローター（１０５）と、その上部に該回転ローター（１０５）を稼働させるための駆動系（１０６）と、分散室（１０３）への流入空気を回転ローター（１０５）内部を通過し排気、かつ粉体材料（１０２）に含まれる超微粉を排出する排気管（１０７）が、具備されている。この回転ローター（１０５）の構成を図２にて示すと、回転ローター（１０５）は円周方向に放射状、あるいは法線に対し一定方向に角度を有した複数の羽根（１０８）と羽根外周部から流入した空気、及び粉体材料（１０２）に含まれる超微粉を排出する排出孔（１０９）で構成されている。
前記第（１）項記載の気流式分級装置は、このとき、回転ローター（１０５）より排気される空気量をＱ１、分散室に流入する空気量をＱ２としたとき、下記式（１）で示される関係式を満足する設定、もしくは構造であることを特徴とするものである。
【００１２】
【数７】
Ｑ１＜Ｑ２＜５×Ｑ１・・・式（１）
【００１３】
分散室（１０３）に流入する空気量Ｑ２は、式（１）の下限を下回ることで、分級室（１０４）から分散室（１０３）に空気が流入し、分散室（１０３）内の粉体材料（１０２）の濃度が上昇し、粉体材料（１０２）の凝集による気流式分級装置（１００）の歩留まりが低下する。また、上限を上回ることで分散室（１０３）に流入した粉体材料（１０２）は、急激に分級室（１０４）に供給されるため、回転ローター（１０５）による超微粉の排出量は低下する。
【００１４】
この装置は、下記式（２）で示される関係式を満足する設定、もしくは構造である場合にさらに好ましい。
【００１５】
【数８】
Ｑ１＜Ｑ２＜３×Ｑ１・・・式（２）
【００１６】
つぎに、前記第（２）項記載の気流式分級装置についてその構成を図３に示す。この装置の場合は、図１に記載した気流式分級装置に関し、分散室（１０３）に接する流入口（１０１）が分散室（１０３）の接線方向より外壁面に沿って接合し、かつ、その流入口（１０１）の幅Ｗが法線基準で下記式（３）より形成されることで、流入粉体材料（１０２）が分散室（１０３）の旋回風速に同調する以前に直接回転ローター（１０５）部に達することを防ぎ、分散室（１０３）から排出される超微粉中の粗粉を減少することを特徴とする。
【００１７】
【数９】
（Ｄ−ｄ）／２×０．２≦Ｗ≦（Ｄ−ｄ）／２×０．９・・・式（３）
【００１８】
流入口（１０１）の幅Ｗは、式（３）の下限を下回ることで流入口（１０１）部の圧損が増大し、乱流度合いが大きくなる。
また、上限を上回ることで流入口（１０１）から流入する粉体材料（１０２）が加速されないまま回転ローター（１０５）に接触する可能性が高くなり、分散室（１０３）から排出される超微粉中の粗粉の割合が多くなる。
【００１９】
さらに前記第（３）項記載の装置についてその構成を図４に示す。
この装置においては前記第（２）項の装置について記載された流入口（１０１）に、可変式邪魔板（１１０）を設け、回転ローター（１０５）の周速、粉体材料（１０２）の粒径、粉体材料（１０２）の投入量に対し、粉体材料（１０２）の流入時ローター（１０５）に直接衝突を防ぐべく、幅Ｗを任意に設定することが可能であることを特徴とする。
【００２０】
さらに前記第（４）項記載の装置についてその構成を図５に示す。
この装置においては前記第（３）項の装置について記載された流入口（１０１）に設けた可変式邪魔板（１１０）による流入幅を、回転ローター（１０５）の周速の設定により、粉体材料（１０２）の粒径、粉体材料（１０２）の投入量による幅Ｗを適切に設定することが可能であることを特徴とする。該気流式分級装置（図１）の分級粒径の微調整は通常回転ローター（１０５）の回転数の変更により行なわれる。この回転数変化を自動で読み取り、外部制御系、例えば、回転検出器を通し、ドライバー（１１１）とモーター（１１２）の組み合わせにより、流入口（１０１）の幅Ｗが予め相関の取れた値に設定される。
また、この入力因子に粉体材料（１０２）の粒径や物性等も加えることが可能である。
【００２１】
さらに前記第（５）項記載の装置についてその構成を図６に示す。
この装置においては、前記第（２）項の装置について記載された流入口（１０１）の内周側端部（１１３）より、分散室（１０３）内部回転ローター（１０５）と分散室（１０３）壁面との間に向け、流入方向に垂直もしくは垂直に対し若干の角度があるガイドベーン（１１４）を有することで、分散室（１０３）に流入直後の加速不良となる粉体材料（１０２）中が回転ローター（１０５）から排気される空気による向心力により、すでに回転ローター（１０５）方向に飛散した粗粉が排出されることを防ぐことを特徴とするものである。ガイドベーン（１１４）の長さは分散室（１０３）に対する流入口（１０１）の進入方向とその法線が垂直で交わる点（１１５）以上あることが望ましい。ガイドベーン（１１４）と分散室（１０３）により形成される流入口（１０１）の幅Ｗは上記制約に準ずる。
【００２２】
さらにまた前記第（６）項記載の装置についてその構成を図７に示す。
この装置の場合には、前記分級機における分散室（１０３）に粉体材料（１０２）を供給する供給配管（１１６）内部に、粉体材料（１０２）を加速させる機能（１１７）を設け、粉体材料（１０２）のすべての速度Ｖ２が、分散室（１０３）に流入する地点で、分散室（１０３）旋回風速Ｖ１と同等の接線方向速度を有することで、超微粉中の粗粉を減少させる機能を持つことを特徴とするものである。
【００２３】
さらにまた前記第（７）項記載の装置についてその構成を図８に示す。
この装置は、供給配管（１１６）の粉体材料（１０２）、加速機能（１１７）が内部に用いられた前記分級装置の分散室（１０３）に粉体材料（１０２）が流入する流入口（１０１）部に、邪魔板（１１８）を開口面に設け、少なくとも一部を可変する構造を持つことで流入口（１０１）の開口断面積の変更が可能となり、前記第（１）項記載の装置における回転ローター（１０５）からの排気空気量Ｑ１と、分散室（１０３）に流入される空気量Ｑ２の関係、加速機能（１１７）の影響を加味したうえで維持し、かつ分散室（１０３）内部旋回風速Ｖ１と流入口（１０１）部風速Ｖ２を任意に設定可能な機能を持つことを特徴とする。
【００２４】
また更に前記第（８）項記載の装置についてその構成を図９に示す。
この分級装置は、前記第（１）項記載の分級装置機における回転ローター（１０５）からの排気空気量Ｑ１と分散室（１０３）に流入される空気量Ｑ２の関係、及び分散室（１０３）内部旋回風速Ｖ１と流入口（１０１）部風速Ｖ２を適正値にするため、例えばローター（１０５）回転数あるいはローター（１０５）を通過する空気量Ｑ１に応じ、供給配管（１１６）内部に設けた粉体材料加速器（１１７）に使用される空気量、または流入口部に設けた邪魔板（１１８）の位置設定等を単独、あるいは同時に自動で制御する機能を有することを特徴とする。
【００２５】
また更に前記第（９）項記載の装置についてその構成を図１０に示す。
この分級装置では、分散室（１０３）上部回転ローターは、供給口（１０１）から流入する粉体材料（１０２）が均一かつ定常的な旋回速度となる加速時間が得られるよう、供給口（１０１）の下部（１１９）と回転ローター（１０５）上部との隙間（１２０）が、分散室（１０３）内径Ｄ、回転ローター（１０５）径ｄにて、下記式（４）より形成されていることを特徴とする。
【００２６】
【数１０】
Ｄ／（Ｄ−ｄ）×１≦Ｈ≦Ｄ／（Ｄ−ｄ）×２５・・・式（４）
【００２７】
隙間（１２０）は式（４）の下限を下回ることで粉体材料（１０２）の回転ローター（１０５）に達するまでの加速時間が縮小され、分散室（１０３）内において粉体材料（１０２）が充分、かつ均一な分級が行なわれなくなる。また、上限を上回ることで分散室（１０３）の高さ方向寸法が大きくなり、回転ローター（１０５）から分散室（１０３）空気中に充分旋回力が加わらないことから、分散室（１０３）より排出される超微粉中の粗粉の割合が多くなる。
【００２８】
また更に前記第（１０）項記載の装置についてその構成を図１１、１２に示す。この装置は、前記分級装置の分散室（１０３）に粉体材料（１０２）が流入する流入口（１０１）の高さ寸法Ｙにおける分散室内径（Ｄ_１）が、回転ローター（１０５）高さ位置の分散室内径（ｄ_１）より大なる構造を形成され、分散室（１０３）に流入した粉体材料（１０２）が重力の影響を受けず、回転ローター（１０５）の上部で分散室（１０３）内部の旋回風速に近づいた後、回転ローター（１０５）を通過する機能を持つことを特徴とするものである。
【００２９】
また更に前記第（１１）項記載の装置についてその構成を図１３、１４に示す。この分級装置は、前記分級装置の分散室（１０３）に粉体材料（１０２）が流入する流入口（１０１）の高さ寸法Ｙに流入口下部に邪魔板（１２１）を円周方向に設け、分散室（１０３）に流入し粉体材料（１０２）が重力の影響を受けず、回転ローター（１０５）の上部で分散室（１０３）内部の旋回風速に近づいた後、回転ローター（１０５）を通過する機能を持つことを特徴とする。
【００３０】
比較例１の装置についてその構成を図１５に示す。
分散室（１３）上部には、回転ローター（１５）とその上部に該回転ローター（１５）を稼働させるための駆動系（１６）と分散室（１３）への流入空気を回転ローター（１５）内部を通過し排気、かつ粉体材料（１２）に含まれる超微粉を排出する排気管（１７）が具備されている。この回転ローター（１５）は、円周方向に放射状あるいは法線に対し一定方向に角度を有した複数の羽根と、羽根外周部から流入した空気及び粉体材料（１２）に含まれる超微粉を排出する排出孔で構成されている。
【００３１】
【実施例】
（実施例１）
前記第（１）項の装置の実施例として以下に示す。
スチレンアクリル共重合体８５重量％と帯電制御剤３重量％、及びカーボンブラック１２重量％の混合物を、エクストルーダーにて溶融混練し、圧延冷却固化させた後、ハンマーミルにて粗粉砕し、次にこの粗粉砕物をジェットミルにて重量平均粒子径７．０μｍに微粉砕して微粉砕物を得た。この微粉砕物を図１に示す本発明の気流式分級装置で、分散室内径２２０ｍｍ、ローター径１２０ｍｍにて、回転ローター外周部周速６０ｍ／ｓ、ローター排気孔を通過する空気量を分散室流入口より投入した粉体材料（１０２）の内、４重量％がローター排気孔より排出される値に設定し、微粉分級を行なった結果、分散室から排出された超微粉中の４μｍ以上の製品分の割合は５５重量％であった。
また、このとき分散室に流入する空気量Ｑ２、及びローターより排気される空気量Ｑ１はそれぞれ１．０ｍ^３／ｍｉｎ、０．８ｍ^３／ｍｉｎであった。
【００３２】
（実施例２）
前記第（２）項の装置の実施例として以下に示す。
スチレンアクリル共重合体８５重量％と帯電制御剤３重量％、及びカーボンブラック１２重量％の混合物を、エクストルーダーにて溶融混練し、圧延冷却固化させた後、ハンマーミルにて粗粉砕し、次にこの粗粉砕物をジェットミルにて重量平均粒子径７．０μｍに微粉砕して微粉砕物を得た。この微粉砕物を図３に示す本発明の気流式分級装置で、分散室内径２２０ｍｍ、ローター径１２０ｍｍ、分散室上部とローター上部が同高さ、流入口幅２５ｍｍにて、回転ローター外周部周速６０ｍ／ｓ、ローター排気孔を通過する空気量を分散室流入口より投入した粉体材料の内、４重量％がローター排気孔より排出される値に設定し、微粉分級を行なった結果、分散室から排出された超微粉中の４μｍ以上の製品分の割合は５０重量％であった。
【００３３】
（実施例３）
前記第（３）項の装置の実施例として以下に示す。
スチレンアクリル共重合体８５重量％と帯電制御剤３重量％、及びカーボンブラック１２重量％の混合物を、エクストルーダーにて溶融混練し、圧延冷却固化させた後、ハンマーミルにて粗粉砕し、次にこの粗粉砕物をジェットミルにて重量平均粒子径７．０μｍに微粉砕して微粉砕物を得た。この微粉砕物を図４に示す本発明の気流式分級装置で、分散室内径２２０ｍｍ、ローター径１２０ｍｍ、流入口幅２０ｍｍにて、回転ローター外周部周速７０ｍ／ｓ、ローター排気孔を通過する空気量を分散室流入口より投入した粉体材料の内、４重量％がローター排気孔より排出される値に設定し、微粉分級を行なった結果、分散室から排出された超微粉中の４μｍ以上の製品分の割合は５０重量％であった。
【００３４】
（実施例４）
前記第（４）項の装置の実施例として以下に示す。
スチレンアクリル共重合体８５重量％と帯電制御剤３重量％、及びカーボンブラック１２重量％の混合物を、エクストルーダーにて溶融混練し、圧延冷却固化させた後、ハンマーミルにて粗粉砕し、次にこの粗粉砕物をジェットミルにて重量平均粒子径７．０μｍに微粉砕して微粉砕物を得た。この微粉砕物を図５に示す本発明の気流式分級装置で、分散室内径２２０ｍｍ、ローター径１２０ｍｍ、分散室上部とローター上部が同高さ、このとき流入口幅は自動演算により２２ｍｍを設定、回転ローター外周部周速６５ｍ／ｓ、ローター排気孔を通過する空気量を分散室流入口より投入した粉体材料の内、４重量％がローター排気孔より排出される値に設定し、微粉分級を行なった結果、分散室から排出された超微粉中の４μｍ以上の製品分の割合は５０重量％であった。
【００３５】
（実施例５）
前記第（５）項の装置の実施例として以下に示す。
スチレンアクリル共重合体８５重量％と帯電制御剤３重量％、及びカーボンブラック１２重量％の混合物を、エクストルーダーにて溶融混練し、圧延冷却固化させた後、ハンマーミルにて粗粉砕し、次にこの粗粉砕物をジェットミルにて重量平均粒子径７．０μｍに微粉砕して微粉砕物を得た。この微粉砕物を図６に示す本発明の気流式分級装置で、分散室内径２２０ｍｍ、ローター径１２０ｍｍ、分散室上部とローター上部が同高さでガイドベーンを設置、流入口幅２５ｍｍにて、回転ローター外周部周速６０ｍ／ｓ、ローター排気孔を通過する空気量を分散室流入口より投入した粉体材料の内、４重量％がローター排気孔より排出される値に設定し、微粉分級を行なった結果、分散室から排出された超微粉中の４μｍ以上の製品分の割合は４７重量％であった。
【００３６】
（実施例６）
前記第（６）項の装置の実施例として以下に示す。
スチレンアクリル共重合体８５重量％と帯電制御剤３重量％、及びカーボンブラック１２重量％の混合物を、エクストルーダーにて溶融混練し、圧延冷却固化させた後、ハンマーミルにて粗粉砕し、次にこの粗粉砕物をジェットミルにて重量平均粒子径７．０μｍに微粉砕して微粉砕物を得た。この微粉砕物を図７に示す本発明の気流式分級装置で、分散室内径２２０ｍｍ、ローター径１２０ｍｍ、流入口幅２５ｍｍ、回転ローター外周部周速６０ｍ／ｓ、供給配管内に粉体材料加速機能としてエジェクター方式を用い、粉体材料を約３０ｍ／ｓまで加速し、ローター排気孔を通過する空気量を分散室流入口より投入した粉体材料の内、４重量％がローター排気孔より排出される値に設定し、微粉分級を行なった結果、分散室から排出された超微粉中の４μｍ以上の製品分の割合は５５重量％であった。
また、このとき分散室に流入する空気量Ｑ２、及びローターより排気される空気量Ｑ１はそれぞれ２．５ｍ^３／ｍｉｎ、０．８ｍ^３／ｍｉｎであった。
【００３７】
（実施例７）
前記第（７）項の装置の実施例として以下に示す。
スチレンアクリル共重合体８５重量％と帯電制御剤３重量％、及びカーボンブラック１２重量％の混合物を、エクストルーダーにて溶融混練し、圧延冷却固化させた後、ハンマーミルにて粗粉砕し、次にこの粗粉砕物をジェットミルにて重量平均粒子径７．０μｍに微粉砕して微粉砕物を得た。この微粉砕物を図８に示す本発明の気流式分級装置で、分散室内径２２０ｍｍ、ローター径１２０ｍｍ、流入口幅２５ｍｍ、回転ローター外周部周速６０ｍ／ｓ、粉体材料加速機能としてエジェクター方式を用い、粉体材料を約３０ｍ／ｓまで加速し、ローター排気孔を通過する空気量を分散室流入口より投入した粉体材料の内、４重量％がローター排気孔より排出される値に設定し、微粉分級を行なった結果、分散室から排出された超微粉中の４μｍ以上の製品分の割合は４５重量％であった。
また、このとき分散室流入口に設けた邪魔板にて分散室に流入する空気量Ｑ２、及びローターより排気される空気量Ｑ１を、それぞれ１．０ｍ^３／ｍｉｎ、０．８ｍ^３／ｍｉｎに設定した。
【００３８】
（実施例８）
前記第（８）項の装置の実施例として以下に示す。
スチレンアクリル共重合体８５重量％と帯電制御剤３重量％、及びカーボンブラック１２重量％の混合物を、エクストルーダーにて溶融混練し、圧延冷却固化させた後、ハンマーミルにて粗粉砕し、次にこの粗粉砕物をジェットミルにて重量平均粒子径７．０μｍに微粉砕して微粉砕物を得た。この微粉砕物を図９に示す本発明の気流式分級装置で、分散室内径２２０ｍｍ、ローター径１２０ｍｍ、流入口幅２５ｍｍにて、回転ローター外周部周速７０ｍ／ｓ、粉体材料加速機能としてエジェクター方式を用い、粉体材料を約３５ｍ／ｓまで加速し、ローター排気孔を通過する空気量を分散室流入口より投入した粉体材料の内、４重量％がローター排気孔より排出される値に設定し、微粉分級を行なった結果、分散室から排出された超微粉中の４μｍ以上の製品分の割合は４０重量％であった。
また、このとき制御系は、自動で分散室流入口に設けた邪魔板にて分散室に流入する空気量Ｑ２、及びローターより排気される空気量Ｑ１を、それぞれ１．０ｍ^３／ｍｉｎ、０．８ｍ^３／ｍｉｎに設定した。
【００３９】
（実施例９）
前記第（９）項の装置の実施例として以下に示す。
スチレンアクリル共重合体８５重量％と帯電制御剤３重量％、及びカーボンブラック１２重量％の混合物を、エクストルーダーにて溶融混練し、圧延冷却固化させた後、ハンマーミルにて粗粉砕し、次にこの粗粉砕物をジェットミルにて重量平均粒子径７．０μｍに微粉砕して微粉砕物を得た。この微粉砕物を図１０に示す本発明の気流式分級装置で、分散室内径２２０ｍｍ、ローター径１２０ｍｍ、流入口幅２５ｍｍ、供給口下部とローター上部が作る隙間３０ｍｍにて、回転ローター外周部周速６０ｍ／ｓ、ローター排気孔を通過する空気量を分散室流入口より投入した粉体材料の内、４重量％がローター排気孔より排出される値に設定し、微粉分級を行なった結果、分散室から排出された超微粉中の４μｍ以上の製品分の割合は４２重量％であった。
のである。
【００４０】
（実施例１０）
前記第（１０）項の装置の実施例として以下に示す。
スチレンアクリル共重合体８５重量％と帯電制御剤３重量％、及びカーボンブラック１２重量％の混合物を、エクストルーダーにて溶融混練し、圧延冷却固化させた後、ハンマーミルにて粗粉砕し、次にこの粗粉砕物をジェットミルにて重量平均粒子径７．０μｍに微粉砕して微粉砕物を得た。この微粉砕物を図１１、１２に示す本発明の気流式分級装置で、分散室内径２２０ｍｍ、ローター径１２０ｍｍ、分散室下部とローター上部が作る隙間３０ｍｍ、流入口幅２５ｍｍにて、回転ローター外周部周速６０ｍ／ｓ、ローター排気孔を通過する空気量を分散室流入口より投入した粉体材料の内、４重量％がローター排気孔より排出される値に設定し、微粉分級を行なった結果、分散室から排出された超微粉中の４μｍ以上の製品分の割合は３８重量％であった。
このとき分散室内にて流入口の高さ位置のみ、流入口より２７０°の範囲で分散室内径がローター部より最大５０ｍｍ大きな構造とした。
【００４１】
（実施例１１）
前記第（１１）項の装置の実施例として以下に示す。
スチレンアクリル共重合体８５重量％と帯電制御剤３重量％、及びカーボンブラック１２重量％の混合物を、エクストルーダーにて溶融混練し、圧延冷却固化させた後、ハンマーミルにて粗粉砕し、次にこの粗粉砕物をジェットミルにて重量平均粒子径７．０μｍに微粉砕して微粉砕物を得た。この微粉砕物を図１３、１４に示す本発明の気流式分級装置で、分散室内径２２０ｍｍ、ローター径１２０ｍｍ、分散室下部とローター上部が作る隙間３０ｍｍ、流入口幅２５ｍｍにて、分散室内面に接し、流入口下部より扇角２７０°にて最大幅２５ｍｍとなる邪魔板を円周方向に設け、回転ローター外周部周速６０ｍ／ｓ、ローター排気孔を通過する空気量を分散室流入口より投入した粉体材料の内、４重量％がローター排気孔より排出される値に設定し、微粉分級を行なった結果、分散室から排出された超微粉中の４μｍ以上の製品分の割合は３８重量％であった。
【００４２】
（比較例１）
比較例１の実施例として以下に示す。
スチレンアクリル共重合体８５重量％と帯電制御剤３重量％、及びカーボンブラック１２重量％の混合物を、エクストルーダーにて溶融混練し、圧延冷却固化させた後、ハンマーミルにて粗粉砕し、次にこの粗粉砕物をジェットミルにて重量平均粒子径７．０μｍに微粉砕して微粉砕物を得た。この微粉砕物を図１５に示す気流式分級装置で、分散室内径２２０ｍｍ、ローター径１２０ｍｍにて、回転ローター外周部周速６０ｍ／ｓ、ローター排気孔を通過する空気量を分散室流入口より投入した粉体材料（１２）の内、４重量％がローター排気孔より排出される値に設定し、微粉分級を行なった結果、分散室から排出された超微粉中の４μｍ以上の製品分の割合は６０重量％であった。
また、このとき分散室に流入する空気量Ｑ２、及びローターより排気される空気量Ｑ１は、それぞれ０．６ｍ^３／ｍｉｎ、０．８ｍ^３／ｍｉｎであった。
【００４３】
上記をまとめたものを表１に示す。
【００４４】
【表１】

【００４５】
【発明の効果】
以上、詳細かつ具体的な説明から明らかなように、本発明の気流式分級装置は、分散室で遠心分離により超微粉を排出する際、すべての粒径の粉体材料（１０２）が、同じ旋回速度にすることが可能となることから排出された超微粉中に含まれる粗粉の割合を削減することが可能となり、粗粉の回収率が増すことから歩留まりが向上する。
また、粉体材料（１０２）の物性や分級条件の設定いかんで、給排風量、流入口法線方向寸法、分散内径、ローター径等の組み合わせ、ガイドベーン、邪魔板、ローター上下機構等の設置および運転の組合せにより更に回収率を向上させることが可能となる。
また、分散室で超微粉が削除し易くなることで、分級室に流入する粉体材料（１０２）中からより多くの超微粉ができることから、超微粉のみ、あるいはその他の粒子との凝集が原因となる歩留まり低下を防ぐことができるという極めて優れた効果を奏するものである。
【図面の簡単な説明】
【図１】本発明の気流式分級装置を示した図である。
【図２】本発明の気流式分級装置における回転ローターの構成例を示した図である。
【図３】本発明における法線方向寸法の関係式を満足する気流式分級装置例を示した図である。
【図４】本発明の、流入口幅が任意に設定可能な構造をもつ気流式分級装置例を示した図である。
【図５】本発明の、流入口幅を自動で形成する機能をもつ気流式分級装置例を示した図である。
【図６】本発明の、ガイドベーンを有する気流式分級装置例を示した図である。
【図７】本発明の、粉体材料を加速させる機能を設けた気流式分級装置例を示した図である。
【図８】本発明の、粉体材料流入口に位置の可変可能な邪魔板を設けた気流式分級装置例を示した図である。
【図９】本発明の、粉体材料加速器および邪魔板を自動で制御する機能をもつ気流式分級装置例を示した図である。
【図１０】本発明における粉体材料流入口下部からローター上面までの距離を満足する気流式分級装置例を示した図である。
【図１１】本発明の、分散室流入口の内壁面の一部がローター部の内径より大きく、段差をもつ気流式分級装置の一例を示した図である。
【図１２】本発明の、分散室流入口の内壁面の一部がローター部の内径より大きく、段差をもつ気流式分級装置の一例を示した図である。
【図１３】本発明の、分散室流入口下部とローター部の間内に邪魔板を設けた気流式分級装置の一例を示した図である。
【図１４】本発明の、分散室流入口下部とローター部の間内に邪魔板を設けた気流式分級装置の一例を示した図である。
【図１５】従来の気流式分級装置を示した図である。
【符号の説明】
１１流入口
１２粉体材料
１３分散室
１４分級室
１５回転ローター
１６駆動系
１７排気管
１０１流入口
１０２粉体材料
１０３分散室
１０４分級室
１０５回転ローター
１０６駆動系
１０７排気管
１０８羽根
１０９排出孔
１１０邪魔板
１１１ドライバー
１１２モーター
１１３内周側端部
１１４ガイドベーン
１１５流入口の進行方向と法線が垂直に交わる点
１１６供給配管
１１７加速させる機能
１１８邪魔板
１１９下部
１２０隙間
１２１邪魔板[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an airflow classifier that uses a swirling airflow to classify fine particle powder such as electrophotographic toner into a predetermined particle size.
[0002]
[Prior art]
Generally, an airflow classifier that uses a swirling airflow to classify fine particle powders such as electrophotographic toner into a predetermined particle size is used. For example, as shown in FIG. 15, the air-flow classifier includes a dispersion chamber (13) for dispersing a powder material (12) supplied together with primary air from an inlet (11) and discharging ultrafine powder together with exhaust gas. , Dispersion room (13) A classification chamber () which is provided continuously below and centrifugally separates the powder material (12) flowing from the dispersion chamber (13) into fine powder and coarse powder. 14 ). Recently, a rotating rotor (15) capable of controlling the swirling wind speed of the dispersion chamber (13) and changing the classification particle size in the classification chamber (14) is provided at the upper part of the dispersion chamber.
[0003]
However, when operating such an airflow classifier (FIG. 15), in addition to the coarse powder contained and discharged on the fine powder side in the classifying chamber (14), the dispersion chamber (13) is introduced from the inlet (11). ) Differs from the flow velocity of the powder material (12) flowing into the classification chamber (12) due to the difference between the mass difference and the acceleration state of the powder material (12). As a result, the dispersion of the centrifugal force increases due to the turbulence region and the increase in the strength, and the coarse powder discharged together with the ultrafine powder also increases.
[0004]
In addition, by performing the operation of reducing the coarse powder discharged from the dispersion chamber (13), the discharge of the ultrafine powder serving as the function of the dispersion chamber (13) also decreases, so that the ratio of the ultrafine powder in the classification chamber (14) increases. In addition, the Van der Waals force of the ultrafine powder is liable to be affected by agglomeration, resulting in a decrease in product yield in a production process having a classifier.
[0005]
[Problems to be solved by the invention]
The present invention has been made to solve the above problems, and an object thereof is to provide a dispersion chamber. From It is an object of the present invention to provide an airflow classifier capable of reducing coarse powder in a discharged powder material and reducing ultrafine powder flowing into a classification chamber.
[0006]
[Means for Solving the Problems]
The object of the present invention is to provide (1) a rotary chamber for dispersing a powder material supplied together with carrier air and separating and discarding ultrafine powder, and a dispersing chamber for dispersing, and a continuous dispersing chamber below the dispersing chamber. Then, in an airflow classifier having a classifying chamber for centrifugally classifying the powder material flowing from the dispersion chamber into fine powder and coarse powder, the amount of air exhausted from a rotor in the dispersion chamber flows into the dispersion chamber in Q1. An airflow classifier characterized in that a setting or a structure is formed that satisfies the relational expression represented by the following expression (1) when the air amount is Q2.
[0007]
(Equation 4)

(2) "The inlet for the powder material to flow into the dispersion chamber of the classifier is located tangentially along the wall of the dispersion chamber, the dimension in the normal direction contacting the dispersion chamber is W, and the inner diameter of the dispersion flowing in is defined as W. D, rotor diameter is d (W, D and d are values expressed in mm) The airflow classification device according to the above (1), characterized in that the structure satisfies the relational expression represented by the following expression (3).
[0008]
(Equation 5)

", (3)" Dimensions in the normal direction of the inlet at which the powder material flows into the dispersion chamber of the classifier " W is , By the variable baffle provided at the inlet Arbitrarily changeable structure Being The airflow classifier according to the above (1), characterized in that: (4) "A mechanism in which the normal dimension W of the inlet port where the powder material flows into the dispersion chamber of the classification device automatically forms the normal dimension W of the inlet port in accordance with fluctuations in the number of rotations of the rotor and the like." The air-flow classification device according to the above item (1), "(5)" in the dispersion chamber from the inlet of the classification device. , Against the inflow direction Vertical or Slightly inclined with respect to the inflow direction The airflow classification device according to the above (1), wherein the airflow classification device has one or a plurality of guide vanes. (6) The airflow classification device according to the above (1), wherein a function of accelerating the powder material is provided inside a supply pipe for supplying the powder material to the dispersion chamber of the classification device. ", (7)" Previous At the inlet where powder material flows into the dispersion chamber of the classifier With a baffle plate that can change the opening area The airflow classification device according to the above (1), wherein: (8) "A function to automatically or independently control the position setting of the powder material accelerator provided inside the supply pipe or the baffle plate provided at the inlet, depending on the rotor speed of the classifier, etc. (9) "The position of the rotor in the dispersion chamber is determined by measuring the distance from the lower part of the inlet into which the powder material flows in to the upper surface of the rotor. H, dispersion chamber diameter D, rotor diameter d (H, D and d are values expressed in mm) The airflow classification device according to claim 1, wherein the structure satisfies a relational expression represented by the following expression (4).
[0009]
(Equation 6)

(10) “In the height dimension Y of the inflow port through which the powder material flows into the dispersion chamber of the classifier” Dispersion room Inner wall One Part is at the rotor height position Dispersion room Larger than the inner diameter, Between the inner wall at the inlet of the dispersion chamber and the inner wall below it The airflow classification device according to the above (1), wherein a structure having a step is formed. (11) "A structure in which a baffle plate is provided on at least a part of the inner wall surface in the circumferential direction between the lower portion of the inlet where the powder material flows into the dispersion chamber of the classifier and the rotor portion is formed. The air-flow classification device according to the above mode (1), "
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings.
[0011]
FIG. 1 shows the configuration of the airflow classifier according to the above item (1).
Above the dispersion chamber (103), a rotating rotor (105), a drive system (106) for operating the rotating rotor (105) above the rotating rotor (105), and air flowing into the dispersion chamber (103) are supplied to the rotating rotor (103). 105) An exhaust pipe (107) for passing the inside and exhausting and discharging the ultrafine powder contained in the powder material (102) is provided. FIG. 2 shows the configuration of the rotating rotor (105). The rotating rotor (105) is composed of a plurality of blades (108) radially extending in a circumferential direction or having an angle in a certain direction with respect to a normal line, and a blade outer peripheral portion. And a discharge hole (109) for discharging the ultra-fine powder contained in the powder material (102) and the air flowing in from the air.
In this case, the airflow classifier according to the above item (1) has the following formula (1), where Q1 is the amount of air exhausted from the rotary rotor (105) and Q2 is the amount of air flowing into the dispersion chamber. The setting or the structure satisfies the relational expression shown.
[0012]
(Equation 7)
Q1 <Q2 <5 × Q1 Equation (1)
[0013]
When the amount of air Q2 flowing into the dispersion chamber (103) is below the lower limit of the equation (1), air flows from the classification chamber (104) into the dispersion chamber (103), and the powder in the dispersion chamber (103) The concentration of the material (102) increases, and the yield of the airflow classifier (100) due to the aggregation of the powder material (102) decreases. Further, the powder material (102) that has flowed into the dispersion chamber (103) by exceeding the upper limit is rapidly supplied to the classification chamber (104), so that the discharge amount of the ultrafine powder by the rotating rotor (105) decreases. .
[0014]
This device is more preferable when the setting or the structure satisfies the relational expression represented by the following expression (2).
[0015]
(Equation 8)
Q1 <Q2 <3 × Q1 Equation (2)
[0016]
Next, FIG. 3 shows the configuration of the airflow classifier described in the above item (2). In the case of this device, the airflow classifier shown in FIG. Relation The inflow port (101) in contact with the dispersion chamber (103) is joined along the outer wall from the tangential direction of the dispersion chamber (103), and the width W of the inflow port (101) is expressed by the following formula (normal). 3) prevents the inflowing powder material (102) from directly reaching the rotating rotor (105) before synchronizing with the swirling wind speed of the dispersion chamber (103), and discharging from the dispersion chamber (103). It is characterized in that the coarse powder in the ultra-fine powder is reduced.
[0017]
(Equation 9)
(D−d) /2×0.2≦W≦ (D−d) /2×0.9 Expression (3)
[0018]
When the width W of the inflow port (101) is below the lower limit of the expression (3), the pressure loss at the inflow port (101) increases, and the degree of turbulence increases.
Further, by exceeding the upper limit, the possibility that the powder material (102) flowing from the inlet (101) comes into contact with the rotating rotor (105) without being accelerated increases, and the ultrafine powder discharged from the dispersion chamber (103) is increased. The proportion of coarse powder in the inside increases.
[0019]
FIG. 4 shows the configuration of the device described in the above item (3).
In this device, a variable baffle (110) is provided at the inlet (101) described in the device of the above item (2), and the peripheral speed of the rotary rotor (105) and the particle size of the powder material (102) are changed. The width W can be arbitrarily set with respect to the diameter and the input amount of the powder material (102) in order to prevent direct collision with the rotor (105) when the powder material (102) flows. I do.
[0020]
FIG. 5 shows the configuration of the device described in the above item (4).
In this device, the inflow width of the variable baffle (110) provided at the inflow port (101) described in the device of the above item (3) is adjusted by setting the peripheral speed of the rotary rotor (105). It is characterized in that it is possible to appropriately set the width W depending on the particle size of the material (102) and the input amount of the powder material (102). Fine adjustment of the classification particle size of the airflow type classification device (FIG. 1) is usually performed by changing the rotation speed of the rotary rotor (105). This change in the number of revolutions is automatically read, and through an external control system, for example, a rotation detector, the width W of the inflow port (101) is set to a value correlated in advance by a combination of the driver (111) and the motor (112). Is set.
It is also possible to add the particle size and physical properties of the powder material (102) to this input factor.
[0021]
FIG. 6 shows the configuration of the device described in the above item (5).
In this apparatus, the dispersion chamber (103) and the internal rotation rotor (105) and the dispersion chamber (103) start from the inner peripheral end (113) of the inflow port (101) described in the apparatus of the above item (2). Aim between the wall and In the inflow direction Vertical or some angle to vertical There is By having the guide vanes (114), the powder material (102), which has poor acceleration immediately after flowing into the dispersion chamber (103), is centrifugal force generated by the air exhausted from the rotary rotor (105), so that the rotary rotor (105) is already used. ) Scatter in the direction Was It is characterized in that coarse powder is prevented from being discharged. The length of the guide vane (114) is desirably equal to or longer than the point (115) where the direction of entry of the inflow port (101) into the dispersion chamber (103) and the normal line intersect perpendicularly. The width W of the inflow port (101) formed by the guide vane (114) and the dispersion chamber (103) conforms to the above restrictions.
[0022]
FIG. 7 shows the configuration of the device described in the above item (6).
In the case of this apparatus, a function (117) for accelerating the powder material (102) is provided inside a supply pipe (116) for supplying the powder material (102) to the dispersion chamber (103) in the classifier. At the point where all the velocities V2 of the powder material (102) flow into the dispersion chamber (103), they have a tangential velocity equivalent to the swirling wind velocity V1 of the dispersion chamber (103), so that coarse powder in the ultrafine powder can be removed. It is characterized by having a function of reducing.
[0023]
FIG. 8 shows the configuration of the device described in the above item (7).
This apparatus comprises an inflow port (102) into which a powder material (102) flows into a dispersion chamber (103) of the classifier in which a powder material (102) of a supply pipe (116) and an acceleration function (117) are used. In the section (101), a baffle plate (118) is provided on the opening surface, and at least a part of the structure is made variable, so that the cross-sectional area of the opening of the inflow port (101) can be changed. The relationship between the amount of exhaust air Q1 from the rotary rotor (105) in the apparatus and the amount of air Q2 flowing into the dispersion chamber (103), the influence of the acceleration function (117) is taken into account, and the dispersion chamber (103) is maintained. ) It has a function of arbitrarily setting the internal swirling wind speed V1 and the inflow port (101) portion wind speed V2.
[0024]
FIG. 9 shows the configuration of the apparatus described in the above item (8).
The classifier according to the above item (1) has a relationship between the amount of exhaust air Q1 from the rotary rotor (105) and the amount of air Q2 flowing into the dispersion chamber (103), and the dispersion chamber (103). In order to make the internal swirling wind speed V1 and the inflow port (101) section wind speed V2 appropriate values, for example, they are provided inside the supply pipe (116) according to the rotation speed of the rotor (105) or the amount of air Q1 passing through the rotor (105). It has a function of automatically controlling the amount of air used in the powder material accelerator (117) or the position setting of the baffle plate (118) provided at the inflow port, alone or simultaneously.
[0025]
FIG. 10 shows the configuration of the device described in the above item (9).
In this classifier, the rotating rotor at the upper part of the dispersion chamber (103) is provided with the supply port (101) so that the powder material (102) flowing from the supply port (101) has a uniform and steady turning speed. ) Lower part (119) and rotating rotor (105) Upper part The gap (120) is formed by the following formula (4) with the inner diameter D of the dispersion chamber (103) and the diameter d of the rotating rotor (105).
[0026]
(Equation 10)
D / (D−d) × 1 ≦ H ≦ D / (D−d) × 25 Expression (4)
[0027]
When the gap (120) is below the lower limit of the formula (4), the acceleration time required for the powder material (102) to reach the rotating rotor (105) is reduced, and the powder material (102) is dispersed in the dispersion chamber (103). However, sufficient and uniform classification cannot be performed. In addition, when the height exceeds the upper limit, the dimension in the height direction of the dispersion chamber (103) increases, and a sufficient swirling force is not applied from the rotating rotor (105) to the air in the dispersion chamber (103). The proportion of coarse powder in the discharged ultrafine powder increases.
[0028]
11 and 12 show the configuration of the device described in the above (10). This apparatus has a height Y of an inlet (101) through which the powder material (102) flows into the dispersion chamber (103) of the classifier. Dispersion room Inner diameter (D ₁ ) Is the height of the rotating rotor (105). Dispersion room Inner diameter (d ₁ )Than Big The powder material (102) flowing into the dispersion chamber (103) is not affected by gravity and approaches the swirling wind speed inside the dispersion chamber (103) above the rotating rotor (105). It has a function of passing through the rotating rotor (105).
[0029]
13 and 14 show the configuration of the device described in the above (11). In this classifier, a baffle plate (121) is provided circumferentially below the inlet at the height Y of the inlet (101) through which the powder material (102) flows into the dispersion chamber (103) of the classifier. After flowing into the dispersion chamber (103) and the powder material (102) is not affected by gravity and approaches the swirling wind speed inside the dispersion chamber (103) above the rotating rotor (105), the rotating rotor (105) It has a function of passing through.
[0030]
FIG. 15 shows the configuration of the device of Comparative Example 1.
In the upper part of the dispersion chamber (13), a rotary rotor (15), a drive system (16) for operating the rotary rotor (15) on the upper part thereof, and the air flowing into the dispersion chamber (13) are supplied to the rotary rotor (15). An exhaust pipe (17) is provided for exhausting through the inside and discharging ultrafine powder contained in the powder material (12). The rotary rotor (15) is provided with a plurality of blades radially or circumferentially at an angle with respect to a normal line, and air flowing from the blade outer periphery and ultrafine powder contained in the powder material (12). It consists of a discharge hole for discharging.
[0031]
【Example】
(Example 1)
An embodiment of the device of the above item (1) will be described below.
A mixture of 85% by weight of a styrene acrylic copolymer, 3% by weight of a charge control agent, and 12% by weight of carbon black is melt-kneaded by an extruder, rolled, cooled and solidified, and coarsely ground by a hammer mill. This coarsely pulverized product was finely pulverized with a jet mill to a weight average particle size of 7.0 μm to obtain a finely pulverized product. This finely pulverized product is subjected to an air flow classification device of the present invention shown in FIG. 1 and a dispersion chamber diameter of 220 mm and a rotor diameter of 120 mm. Of the powder material (102) charged from the inlet, 4% by weight was set to a value that is discharged from the rotor exhaust hole, and the fine powder was classified. As a result, 4 μm or more of the ultrafine powder discharged from the dispersion chamber was separated. The product fraction was 55% by weight.
At this time, the air amount Q2 flowing into the dispersion chamber and the air amount Q1 exhausted from the rotor are each 1.0 m. ³ / Min, 0.8m ³ / Min.
[0032]
(Example 2)
An example of the device of the above item (2) will be described below.
A mixture of 85% by weight of a styrene acrylic copolymer, 3% by weight of a charge control agent, and 12% by weight of carbon black is melt-kneaded by an extruder, rolled, cooled and solidified, and coarsely ground by a hammer mill. This coarsely pulverized product was finely pulverized with a jet mill to a weight average particle size of 7.0 μm to obtain a finely pulverized product. The finely pulverized product was subjected to an airflow type classification device of the present invention shown in FIG. 3 by using a dispersion chamber having a diameter of 220 mm, a rotor diameter of 120 mm, an upper portion of the dispersion chamber and an upper portion of the rotor having the same height, and an inlet width of 25 mm. At a speed of 60 m / s, the amount of air passing through the rotor exhaust hole was set to a value at which 4% by weight of the powder material charged from the dispersion chamber inlet was discharged from the rotor exhaust hole, and the fine powder was classified. The proportion of the product having a size of 4 μm or more in the ultrafine powder discharged from the dispersion chamber was 50% by weight.
[0033]
(Example 3)
An example of the device of the above item (3) will be described below.
A mixture of 85% by weight of a styrene acrylic copolymer, 3% by weight of a charge control agent, and 12% by weight of carbon black is melt-kneaded by an extruder, rolled, cooled and solidified, and coarsely ground by a hammer mill. This coarsely pulverized product was finely pulverized with a jet mill to a weight average particle size of 7.0 μm to obtain a finely pulverized product. This finely pulverized product is passed through a rotor exhaust hole at a peripheral speed of 70 m / s at an inner diameter of a dispersion chamber of 220 mm, a diameter of a rotor of 120 mm, and an inlet width of 20 mm by a gas flow classifier of the present invention shown in FIG. The amount of air was set to a value such that 4% by weight of the powder material charged from the inlet of the dispersion chamber was discharged from the rotor exhaust hole, and the fine powder was classified. As a result, 4 μm in the ultrafine powder discharged from the dispersion chamber was determined. The proportion of the above products was 50% by weight.
[0034]
(Example 4)
An example of the device of the above item (4) will be described below.
A mixture of 85% by weight of a styrene acrylic copolymer, 3% by weight of a charge control agent, and 12% by weight of carbon black is melt-kneaded by an extruder, rolled, cooled and solidified, and coarsely ground by a hammer mill. This coarsely pulverized product was finely pulverized with a jet mill to a weight average particle size of 7.0 μm to obtain a finely pulverized product. This finely pulverized product is subjected to an airflow classification device of the present invention shown in FIG. 5 and the dispersion chamber diameter is 220 mm, the rotor diameter is 120 mm, the upper part of the dispersion chamber and the upper part of the rotor are the same height, and the inlet width is set to 22 mm by automatic calculation. The peripheral speed of the rotating rotor is 65 m / s, and the amount of air passing through the rotor exhaust hole is set to a value such that 4% by weight of the powder material input from the dispersion chamber inlet is discharged from the rotor exhaust hole. As a result of classification, the proportion of the product of 4 μm or more in the ultrafine powder discharged from the dispersion chamber was 50% by weight.
[0035]
(Example 5)
An example of the device of the above item (5) will be shown below.
A mixture of 85% by weight of a styrene acrylic copolymer, 3% by weight of a charge control agent, and 12% by weight of carbon black is melt-kneaded by an extruder, rolled, cooled and solidified, and coarsely ground by a hammer mill. This coarsely pulverized product was finely pulverized with a jet mill to a weight average particle size of 7.0 μm to obtain a finely pulverized product. This finely pulverized product is subjected to an airflow classification device of the present invention shown in FIG. 6, a dispersion chamber diameter of 220 mm, a rotor diameter of 120 mm, a guide vane installed at the same height in the dispersion chamber upper part and the rotor upper part, and an inlet width of 25 mm. The outer peripheral portion of the rotating rotor has a peripheral velocity of 60 m / s, and the amount of air passing through the rotor exhaust hole is set to a value such that 4% by weight of the powder material input from the inlet of the dispersion chamber is discharged from the rotor exhaust hole. As a result, the proportion of the product having a size of 4 μm or more in the ultrafine powder discharged from the dispersion chamber was 47% by weight.
[0036]
(Example 6)
An example of the device of the above item (6) will be described below.
A mixture of 85% by weight of a styrene acrylic copolymer, 3% by weight of a charge control agent, and 12% by weight of carbon black is melt-kneaded by an extruder, rolled, cooled and solidified, and coarsely ground by a hammer mill. This coarsely pulverized product was finely pulverized with a jet mill to a weight average particle size of 7.0 μm to obtain a finely pulverized product. This finely pulverized product is subjected to a powder classifier of the present invention shown in FIG. 7 by means of a dispersion chamber having a diameter of 220 mm, a rotor diameter of 120 mm, an inlet width of 25 mm, a peripheral speed of a rotary rotor of 60 m / s, and a powder material accelerating into a supply pipe. Using the ejector method as a function, the powder material is accelerated to about 30 m / s, and 4% by weight of the powder material discharged from the rotor exhaust port through the rotor exhaust port is discharged by 4% by weight of the amount of air passing through the rotor exhaust port. As a result of fine powder classification, the proportion of products having a particle size of 4 μm or more in the ultrafine powder discharged from the dispersion chamber was 55% by weight.
At this time, the air amount Q2 flowing into the dispersion chamber and the air amount Q1 exhausted from the rotor are each 2.5 m. ³ / Min, 0.8m ³ / Min.
[0037]
(Example 7)
An example of the device of the above item (7) will be described below.
A mixture of 85% by weight of a styrene acrylic copolymer, 3% by weight of a charge control agent, and 12% by weight of carbon black is melt-kneaded by an extruder, rolled, cooled and solidified, and coarsely ground by a hammer mill. This coarsely pulverized product was finely pulverized with a jet mill to a weight average particle size of 7.0 μm to obtain a finely pulverized product. This finely pulverized product is subjected to an air flow classification device of the present invention shown in FIG. 8 using a dispersion chamber inner diameter of 220 mm, a rotor diameter of 120 mm, an inlet width of 25 mm, a peripheral speed of a rotary rotor of 60 m / s, and an ejector method as a powder material accelerating function. The powder material is accelerated to about 30 m / s by using the above method, and the amount of air passing through the rotor exhaust hole is reduced to a value such that 4% by weight of the powder material input from the inlet of the dispersion chamber is discharged from the rotor exhaust hole. As a result of setting and performing fine powder classification, the proportion of the product of 4 μm or more in the ultrafine powder discharged from the dispersion chamber was 45% by weight.
At this time, the amount of air Q2 flowing into the dispersion chamber through the baffle provided at the inlet of the dispersion chamber and the amount of air Q1 exhausted from the rotor are each 1.0 m. ³ / Min, 0.8m ³ / Min.
[0038]
(Example 8)
An embodiment of the device of the above item (8) will be shown below.
A mixture of 85% by weight of a styrene acrylic copolymer, 3% by weight of a charge control agent, and 12% by weight of carbon black is melt-kneaded by an extruder, rolled, cooled and solidified, and coarsely ground by a hammer mill. This coarsely pulverized product was finely pulverized with a jet mill to a weight average particle size of 7.0 μm to obtain a finely pulverized product. This finely pulverized product is subjected to the airflow classifier of the present invention shown in FIG. 9 with a dispersion chamber inner diameter of 220 mm, a rotor diameter of 120 mm, an inlet width of 25 mm, a peripheral speed of the outer periphery of the rotary rotor of 70 m / s, and a powder material accelerating function. Using the ejector method, the powder material is accelerated to about 35 m / s, and 4% by weight of the powder material, which is supplied from the inlet of the dispersion chamber by the amount of air passing through the rotor exhaust hole, is discharged from the rotor exhaust hole. As a result of setting the value to a value and performing fine powder classification, the proportion of products having a particle size of 4 μm or more in the ultrafine powder discharged from the dispersion chamber was 40% by weight.
At this time, the control system automatically reduces the amount of air Q2 flowing into the dispersion chamber by the baffle provided at the inlet of the dispersion chamber and the amount of air Q1 exhausted from the rotor by 1.0 m. ³ / Min, 0.8m ³ / Min.
[0039]
(Example 9)
An embodiment of the device of the above item (9) will be shown below.
A mixture of 85% by weight of a styrene acrylic copolymer, 3% by weight of a charge control agent, and 12% by weight of carbon black is melt-kneaded by an extruder, rolled, cooled and solidified, and coarsely ground by a hammer mill. This coarsely pulverized product was finely pulverized with a jet mill to a weight average particle size of 7.0 μm to obtain a finely pulverized product. This finely pulverized product is subjected to an airflow classification device of the present invention shown in FIG. 10 using a dispersion chamber diameter of 220 mm, a rotor diameter of 120 mm, an inlet width of 25 mm, Supply port At a gap of 30 mm formed between the lower part and the upper part of the rotor, 4% by weight of the powder material charged into the dispersion chamber inlet by the amount of air passing through the rotor exhaust hole at a peripheral speed of 60 m / s at the peripheral portion of the rotary rotor was used. As a result of setting the value to a value discharged more and performing fine powder classification, the proportion of the product of 4 μm or more in the ultrafine powder discharged from the dispersion chamber was 42% by weight.
It is.
[0040]
(Example 10)
An embodiment of the device of the above item (10) will be shown below.
A mixture of 85% by weight of a styrene acrylic copolymer, 3% by weight of a charge control agent, and 12% by weight of carbon black is melt-kneaded by an extruder, rolled, cooled and solidified, and coarsely ground by a hammer mill. This coarsely pulverized product was finely pulverized with a jet mill to a weight average particle size of 7.0 μm to obtain a finely pulverized product. The finely pulverized product is subjected to the air-flow classifier of the present invention shown in FIGS. 11 and 12 using a rotor inside diameter of 220 mm, a rotor diameter of 120 mm, a gap formed by the lower part of the dispersion chamber and the upper part of the rotor of 30 mm, and an inlet width of 25 mm. At a peripheral speed of 60 m / s, the amount of air passing through the rotor exhaust hole was set to a value such that 4% by weight of the powder material input from the dispersion chamber inlet was discharged from the rotor exhaust hole, and fine powder classification was performed. As a result, the ratio of the product of 4 μm or more in the ultrafine powder discharged from the dispersion chamber was 38% by weight.
At this time, only the height position of the inflow port in the dispersion chamber was set so that the diameter of the dispersion chamber was at most 50 mm larger than the rotor portion within a range of 270 ° from the inflow port.
[0041]
(Example 11)
An embodiment of the device of the above item (11) will be shown below.
A mixture of 85% by weight of a styrene acrylic copolymer, 3% by weight of a charge control agent, and 12% by weight of carbon black is melt-kneaded by an extruder, rolled, cooled and solidified, and coarsely ground by a hammer mill. This coarsely pulverized product was finely pulverized with a jet mill to a weight average particle size of 7.0 μm to obtain a finely pulverized product. The finely pulverized product is subjected to an airflow classifier of the present invention shown in FIGS. 13 and 14 using a dispersion chamber inner diameter of 220 mm, a rotor diameter of 120 mm, a gap formed between the lower part of the dispersion chamber and the upper part of the rotor of 30 mm, and an inlet width of 25 mm. And a baffle plate having a maximum width of 25 mm at a fan angle of 270 ° from the lower part of the inlet is provided in the circumferential direction, and the peripheral speed of the outer periphery of the rotating rotor is 60 m / s, and the amount of air passing through the rotor exhaust hole is determined by the inlet of the dispersion chamber. Of the powder materials charged, 4% by weight was set to a value that was discharged from the rotor exhaust hole, and the fine powder was classified. As a result, the proportion of the product of 4 μm or more in the ultrafine powder discharged from the dispersion chamber was as follows: 38% by weight.
[0042]
(Comparative Example 1)
An example of Comparative Example 1 is shown below.
A mixture of 85% by weight of a styrene acrylic copolymer, 3% by weight of a charge control agent, and 12% by weight of carbon black is melt-kneaded by an extruder, rolled, cooled and solidified, and coarsely ground by a hammer mill. This coarsely pulverized product was finely pulverized with a jet mill to a weight average particle size of 7.0 μm to obtain a finely pulverized product. This finely pulverized product is subjected to an airflow classifier shown in FIG. 15 and a flow rate of air passing through a rotor exhaust hole at a peripheral speed of an outer peripheral portion of the rotor of 60 m / s at a dispersion chamber diameter of 220 mm and a rotor diameter of 120 mm from a dispersion chamber inlet. A value of 4% by weight of the charged powder material (12) was set to a value that is discharged from the rotor exhaust hole, and the fine powder was classified. As a result, the amount of the product of 4 μm or more in the ultrafine powder discharged from the dispersion chamber was determined. The proportion was 60% by weight.
At this time, the air amount Q2 flowing into the dispersion chamber and the air amount Q1 exhausted from the rotor are each 0.6 m. ³ / Min, 0.8m ³ / Min.
[0043]
Table 1 summarizes the above.
[0044]
[Table 1]

[0045]
【The invention's effect】
As apparent from the detailed and specific description above, the air-flow classifier of the present invention, when discharging ultrafine powder by centrifugation in the dispersion chamber, the powder material (102) of all particle diameters is the same. Since the swirling speed can be set, the ratio of the coarse powder contained in the discharged ultrafine powder can be reduced, and the recovery rate of the coarse powder increases, thereby improving the yield.
In addition, by setting the physical properties and classification conditions of the powder material (102), a combination of air supply / discharge air volume, inlet normal direction size, dispersion inner diameter, rotor diameter, etc., guide vanes, baffle plates, rotor up / down mechanism, etc. It is possible to further improve the recovery rate by a combination of and operation.
In addition, since the ultrafine powder is easily removed in the dispersion chamber, more ultrafine powder is generated from the powder material (102) flowing into the classification chamber, so that only the ultrafine powder or aggregation with other particles is caused. This is an extremely excellent effect that the yield can be prevented from lowering.
[Brief description of the drawings]
FIG. 1 is a view showing an airflow classifier of the present invention.
FIG. 2 is a diagram showing a configuration example of a rotary rotor in an airflow classifier of the present invention.
FIG. 3 is a diagram showing an example of an airflow classifier that satisfies a relational expression of a normal dimension in the present invention.
FIG. 4 is a view showing an example of an airflow classifier having a structure in which an inlet width can be arbitrarily set according to the present invention.
FIG. 5 is a view showing an example of an airflow classifier having a function of automatically forming an inlet width according to the present invention.
FIG. 6 is a view showing an example of an airflow classifier having guide vanes according to the present invention.
FIG. 7 is a view showing an example of an airflow classifier provided with a function of accelerating a powder material according to the present invention.
FIG. 8 is a diagram showing an example of an airflow classifier in which a baffle plate whose position can be varied is provided at a powder material inlet, according to the present invention.
FIG. 9 is a view showing an example of an airflow classifier having a function of automatically controlling a powder material accelerator and a baffle plate according to the present invention.
FIG. 10 is a diagram showing an example of an airflow classifier that satisfies the distance from the lower part of the powder material inlet to the upper surface of the rotor in the present invention.
FIG. 11 is a view showing an example of an airflow type classification device according to the present invention in which a part of the inner wall surface of the inlet of the dispersion chamber is larger than the inner diameter of the rotor portion and has a step.
FIG. 12 is a view showing an example of an airflow type classification device according to the present invention, in which a part of the inner wall surface of the inlet of the dispersion chamber is larger than the inner diameter of the rotor part and has a step.
FIG. 13 is a diagram showing an example of an airflow classifier having a baffle plate provided between a lower part of a dispersion chamber inlet and a rotor part according to the present invention.
FIG. 14 is a view showing an example of an airflow classifier having a baffle plate provided between a lower part of a dispersion chamber inlet and a rotor part according to the present invention.
FIG. 15 is a view showing a conventional airflow classifier.
[Explanation of symbols]
11 Inlet
12 Powder material
13 Distribution room
14 Classification room
15 Rotating rotor
16 Drive system
17 Exhaust pipe
101 Inlet
102 Powder material
103 Distribution room
104 Classification room
105 rotating rotor
106 drive system
107 exhaust pipe
108 feather
109 outlet
110 Baffle
111 Driver
112 motor
113 Inner circumference end
114 Guide Vane
115 Point where the direction of flow and the normal line intersect perpendicularly
116 Supply piping
117 Acceleration Function
118 Baffle
119 bottom
120 gap
121 Baffle

Claims

Dispersing the powder material supplied together with the carrier air, a dispersion chamber having a rotary rotor for separating and disposing of ultrafine powder, and a powder material continuously flowing in from the dispersion chamber below the dispersion chamber. In an airflow classifier having a classifying chamber for centrifugally classifying fine powder and coarse powder, when the amount of air exhausted from the rotor in the dispersion chamber is Q1 and the amount of air flowing into the dispersion chamber is Q2, the following equation ( An airflow classifier having a setting or a structure that satisfies the relational expression shown in 1).

The inflow port where the powder material flows into the dispersion chamber of the classifier is located tangentially along the wall of the dispersion chamber, the normal dimension in contact with the dispersion chamber is W, the internal diameter of the dispersion flowing is D, and the rotor diameter is d. The air-flow classification device according to claim 1, wherein a structure that satisfies a relational expression represented by the following expression (3) when (W, D, and d are values expressed in mm ) is satisfied.

2. A structure in which a dimension W in a normal direction of an inlet at which a powder material flows into a dispersion chamber of the classifier can be arbitrarily changed by a variable baffle provided at the inlet. 2. An airflow classification device according to item 1.

An inlet normal dimension W in which the powder material flows into the dispersion chamber of the classification device has a mechanism for automatically forming the inlet normal dimension W according to fluctuations in the rotor rotation speed and the like. The airflow type classification device according to claim 1.

2. The method according to claim 1, further comprising: a single or a plurality of guide vanes arranged perpendicularly to the inflow direction or slightly inclined with respect to the inflow direction, inside the dispersion chamber from the inflow port of the classification device. An airflow classifier as described.

The airflow classification device according to claim 1, wherein a function of accelerating the powder material is provided inside a supply pipe for supplying the powder material to the dispersion chamber of the classification device.

The inlet portion powder material flows into the dispersion chamber before Symbol classifier, air classifier according to claim 1, characterized in that it comprises a baffle plate capable of changing the opening area.

According to the rotor speed or the like of the classifier, the powder material accelerator provided inside the supply pipe, or has a function to automatically control the position setting of the baffle plate provided at the inlet, alone or simultaneously at the same time. The airflow type classification device according to claim 1.

The position of the rotor in the dispersion chamber is defined as the distance from the lower part of the inlet into which the powder material flows into the upper surface of the rotor, H as the diameter of the dispersion chamber, and d as the rotor diameter (H, D, and d are values expressed in mm). The airflow classification device according to claim 1, wherein the structure satisfies a relational expression represented by the following expression (4).

Part of the dispersion chamber wall at the height Y of the inlet port of the powder material flows into the dispersion chamber of the classifier is greater than the dispersion chamber inner diameter of the rotor height, and the inner wall of the inlet position of the dispersion chamber The airflow classification device according to claim 1, wherein a structure having a step is formed between the inner wall and a lower inner wall .

A structure in which a baffle plate is provided in a circumferential direction on at least a part of the inner wall surface, between the lower portion of the inflow port where the powder material flows into the dispersion chamber of the classification device and the rotor portion, The airflow type classification device according to claim 1.