JP3712432B2

JP3712432B2 - Aggregate supply control method in asphalt plant

Info

Publication number: JP3712432B2
Application number: JP31316994A
Authority: JP
Inventors: 雅也松島; 昇奥村
Original assignee: 日工株式会社; 日工電子工業株式会社
Priority date: 1994-12-16
Filing date: 1994-12-16
Publication date: 2005-11-02
Anticipated expiration: 2020-11-02
Also published as: JPH08170305A

Description

【０００１】
【産業上の利用分野】
本発明は、道路舗装材であるアスファルト合材を製造するアスファルトプラントの骨材供給制御方法に関する。
【０００２】
【従来の技術】
一般にアスファルトプラントにおいては、各種骨材を種別毎に貯蔵する骨材ホッパから所望の割合で骨材を切り出し、骨材搬送用ベルコンにより加熱装置であるドライヤに送り込み、ドライヤにより加熱した後にプラント本体上部に持ち上げ、振動篩により粒径別に篩い分けて下位に配設する骨材貯蔵ビンの区画室に粒径別に一時貯蔵する。そして出荷要請に基づいて製造するアスファルト合材の配合に基づいて各種粒径の骨材を各区画室より払い出し、所定量計量してアスファルト等の他の材料と共にミキサにより混合してアスファルト合材を製造している。
【０００３】
そして合材製造時の骨材供給量の制御は、出荷する合材種別に応じて各骨材ホッパより所定の割合で骨材を払い出し、搬送途中に配設したコンベヤスケールにより総骨材供給量を測定し、設定された総骨材供給量に達すると骨材の払い出しを停止するように制御している。
【０００４】
【発明が解決しようとする課題】
しかしながら、上記従来の骨材供給制御方法では出荷合材に使用する総骨材量を供給することができるのであるが、骨材貯蔵ビンの各区画室に分配貯蔵された骨材量は、骨材ホッパにおける骨材粒度の変動や、スクリーンの篩効率、目詰まり等により過不足が生じることがある。このため、不足が生じないように骨材を多めに供給することもあって、一部の区画室では骨材の過剰供給によるオーバーフローが生じたり、また出荷終了後に多量の残材が残ることもあって煩わしい残材抜き取り作業をしなくてはならないこともある。
【０００５】
本発明は上記の点に鑑み、アスファルト合材の出荷量に応じて適正な骨材量を骨材貯蔵ビンに供給し、出荷終了後に骨材貯蔵ビンに骨材が残材として極力残らないようにした効率の良いアスファルトプラントの骨材供給制御方法を提供することを目的とする。
【０００６】
【課題を解決するための手段】
本発明は上記の目的を達成するために、請求項１の骨材供給制御方法は、骨材貯蔵ビンの各区画室に貯蔵量を検出するレベル計を配設すると共に、該レベル計よりの信号により骨材供給量を制御する骨材供給制御装置を具備し、骨材ホッパより骨材を供給する時に、予め、出荷しようとするアスファルト合材の出荷予定量と配合比とから各骨材の供給量を演算し、演算した各骨材の供給量を骨材貯蔵ビンの各区画室に供給したときに各骨材が到達する骨材貯蔵レベルを演算して目標レベルとして設定し、骨材供給中にアスファルト合材の出荷が行われておれば、アスファルト合材を１バッチ製造出荷する毎に予め設定した目標レベルより１バッチ分の骨材貯蔵レベルを減算して目標レベルを再設定し、レベル計により検出した各区画室の骨材貯蔵レベルが前記目標レベルに達した時点で骨材の供給を停止するようにしたことを特徴としている。
【０００７】
また、請求項２記載の骨材供給制御方法は、前記骨材供給中は、所定のタイミング毎に前記レベル計によって各区画室の骨材貯蔵レベルを検出し、検出した前回と今回との骨材貯蔵レベル差と、この間に各区画室から払い出された骨材量とより各区画室への骨材の実供給割合を演算し、該実供給割合と出荷合材の骨材配合比に差異があるならば、出荷合材の各区画室の骨材使用量に対して特定の区画室への骨材供給に過不足有りと判断し、各区画室への骨材の実供給割合が出荷合材の骨材配合比に近付くように各可変速フィーダの切り出し割合を逐次補正して、出荷合材の各区画室の骨材使用量に対して過不足なく各区画室へ骨材を供給するようにしたことを特徴としている。
【０００８】
【作用】
本発明の請求項１記載の骨材供給制御方法によれば、骨材供給時に出荷予定量とその配合比とより所要骨材量を演算すると共に、その所要骨材量から骨材貯蔵ビンの各区画室に貯蔵する時の目標レベルを演算して設定し、この目標レベルと各区画室に配設したレベル計によって検出した骨材の貯蔵レベルとが一致すると骨材の供給を停止するものである。そして出荷が行われている間は、１バッチ毎に骨材貯蔵ビンより払い出した１バッチ分の骨材量を先に設定した目標レベルより減算して再度目標レベルを設定し、レベル計により検出した骨材貯蔵レベルが再設定した目標レベルに達した時点で骨材の供給を停止する。このことにより出荷に必要な分だけの骨材量を供給することになり、出荷終了時には骨材貯蔵ビンに骨材が残材として残留するのが少なくなるのである。
【０００９】
また、請求項２記載の骨材供給制御方法によれば、前記骨材供給中に、レベル計によって各区画室の骨材貯蔵レベルを検出し、検出した前回と今回との骨材貯蔵レベル差より各区画室に粒径別に分配される骨材の実供給割合を演算する。そして実供給割合と出荷合材の骨材配合比に差異があるならば、各区画室への骨材の実供給割合が出荷合材の骨材配合比に近付くように可変速フィーダの切り出し割合を逐次補正し、出荷合材の使用骨材量に見合った骨材供給を常に行うものである。これによって出荷途中においても骨材を過不足なく骨材貯蔵ビンに供給していけるので、出荷中に一部骨材の過小供給による骨材切れを起こすこともなく、また各骨材の貯蔵量が目標レベルに到達するのがほぼ同時期となって効率の良い骨材供給を行うことができる。
【００１０】
【実施例】
以下本発明の実施例を図面に基づいて説明する。
【００１１】
１ａ〜１ｄは骨材を種別毎に貯蔵する骨材ホッパであり、可変速フィーダ２ａ〜２ｄにより所定量の骨材を切り出し、引出しコンベヤ３、計量コンベヤ４を介して骨材加熱装置であるドライヤ５に投入し、ドライヤ５内を通過する間にバーナ６の熱風により所定の温度まで加熱昇温する。
【００１２】
加熱した骨材はバケットエレベータ７によりプラント本体上部まで持ち上げ、振動篩８により骨材を粒径別に篩い分け、内部を複数に区画した骨材貯蔵ビン９に粒径別に貯蔵される。９ａ〜９ｄは砂利大、砂利中、砂利小及び砂の粒径別に骨材を貯蔵する区画室であり、それぞれの区画室９ａ〜９ｄには骨材貯蔵レベルを検出するレベル計１０を配設している。図示したレベル計は静電容量式レベル計を利用した連続式レベル計であるが、このほかに区画室を独立させてロードセルを利用したり、また、非連続式レベル計のトルクモータ式及び熱伝対などを多数使用することにより、連続して骨材貯蔵レベルを計測するようにしても良い。
【００１３】
１１は骨材ホッパ１ａ〜１ｄの骨材の切り出しを制御する骨材供給制御装置であって、レベル計１０よりのデータや操作盤１２とのデータを送受信する送受信部１３、取り込んだレベルデータより各種演算を行う演算部１４、各種データを記憶する記憶部１５、各種設定データを入力する入力部１６及び骨材ホッパ１ａ〜１ｄの可変速フィーダ２ａ〜２ｄの速度を設定する速度設定器１７を備える共に、これらの各要素を制御する制御部１８を備えている。
【００１４】
前記骨材ホッパ１ａ〜１ｄからの骨材の切り出し制御は、出荷合材の骨材配合に応じた切り出し割合にて各種骨材を切り出したり、また骨材貯蔵ビン９の各区画室９ａ〜９ｄのレベル計１０により各区画室９ａ〜９ｄの骨材貯蔵レベルを検出し、この骨材貯蔵レベルから各区画室への骨材供給割合や貯蔵量を演算し、これをフィードバックして骨材の切り出し速度を補正し、出荷合材の骨材使用量に対し過不足なしに骨材を供給するようにしている。
【００１５】
そして各区画室９ａ〜９ｄに貯蔵された各種粒径の骨材は、出荷合材の骨材配合に基づいて区画室９ａ〜９ｄから下位に設けた骨材計量槽１９に払い出して計量し、石粉計量槽２０及びアスファルト計量槽２１で計量した石粉及び溶融アスファルトと共にミキサ２２に投入して所定時間混合してアスファルト合材を製造している。
【００１６】
次に、骨材貯蔵ビン９の骨材貯蔵レベルに基づいて骨材の供給制御を行う方法について、図２、図３のフローチャートにより説明する。図中のＳ１〜Ｓ２２はフローチャートの各手順を表わすステップを示す。
【００１７】
先ず、運転を開始する前に初期設定としてアスファルト合材の品種及びその配合等を操作盤１２に登録する（Ｓ１）。また、骨材供給時に、アスファルト合材の品種に対応させて各骨材ホッパ１ａ〜１ｄからの骨材切り出し速度を設定するための切り出し割合の登録を行う（Ｓ２）。そして骨材の総供給量を設定すれば切り出し割合から各骨材ホッパ１ａ〜１ｄの切り出し速度が決定される。なお、アスファルト合材の品種により決定した各骨材の切り出し割合に応じて各骨材ホッパ１ａ〜１ｄの切り出し速度を直接入録しても良い。
【００１８】
前記登録が完了すれば更に他の合材種類について登録を継続するか否かを判断し（Ｓ３）、終了ならばＥＮＤに進み登録操作を終了し、継続する場合はステップＳ１に戻って製造する全ての合材種類について登録作業を行う。
【００１９】
次に、プラントの運転を開始して操作盤１２に出荷する合材種類及び出荷予定量を入力すると、骨材供給制御装置１１側ではデータ送受信部１３を介して出荷合材の配合内容を受信し（Ｓ４）、続いて出荷予定量を受信する（Ｓ５）。配合内容を受信すると、次に配合内容に見合った各骨材ホッパ１ａ〜１ｄの切り出し割合を読み込む（Ｓ６）。また、出荷合材の配合内容と出荷予定量に基づいて必要とされる各骨材の供給量を演算して設定する（Ｓ７）。このとき、演算して求めた各骨材供給量に割り増し供給量としてプラスαを加味して供給量が不足しないように考慮しておくと良い。
【００２０】
また、各骨材供給量が設定されると、各骨材供給量に基づく骨材貯蔵ビン９の骨材貯蔵の目標レベルの演算が行われる（Ｓ８）。この骨材貯蔵ビンの目標レベルは、各骨材供給量を骨材貯蔵ビン９の対応する区画室９ａ〜９ｄに送り込んだ時に各骨材が到達する骨材貯蔵レベルである。この骨材貯蔵レベルは空量を０％、満量を１００％として％表示にて表わすと良い。なお、各骨材供給量が対応する区画室９ａ〜９ｄに貯蔵できる量であるなら問題ないが、量的に多くて全量を供給した時にオーバーフローする場合には、とりあえずはその区画室の貯蔵量の９０％を目標レベルとし、骨材の出荷払い出しがあればその目標レベルを逐次修正していく。
【００２１】
前記目標レベルは骨材貯蔵ビンに貯蔵する最終的な目標貯蔵レベルであるので、実際の骨材切り出し停止は、目標レベルから搬送過程中に滞留している骨材量を差し引いた骨材貯蔵レベルに達した時点で骨材の切り出しを停止する必要がある。このため、目標レベルより搬送過程に滞留する骨材量を差し引いた予測目標レベルの演算を行い、これを骨材供給制御の目標レベルとして設定する（Ｓ９）。
【００２２】
予測目標レベルの設定が完了すると骨材供給の開始が可能となる。骨材の供給開始スイッチＯＮにより設定された各骨材の切り出し割合に基づいて速度設定器１７から各骨材ホッパ１ａ〜１ｄの可変速フィーダ２ａ〜２ｄに対して切り出し速度が指令され、各骨材ホッパ１ａ〜１ｄから所定量の骨材が切り出される（Ｓ１０）。この骨材の切り出し開始と共に移送タイマーを起動させる（Ｓ１１）。この移送タイマーは、切り出された骨材が骨材貯蔵ビン９まで到達する時間を設定している。
【００２３】
そして移送タイマーがカウントアップして各骨材ホッパ１ａ〜１ｄから切り出した骨材が骨材貯蔵ビン９に供給され始めると、プラントの稼動状況を検出してアスファルト合材の出荷（骨材の払い出し）が行われているか否かを判断する（Ｓ１２）。そしてアスファルト合材の出荷が行われていなければ、骨材の払い出しなしに骨材貯蔵ビン９の骨材貯蔵レベルが徐々に上昇している状態であり、骨材貯蔵レベルを所定の時間間隔毎で測定するための測定用タイマーがカウントアップしたか否かを判断し、まだカウントアップされていなければカウントアップ待ちとなり、カウントアップされていれば、各区画室９ａ〜９ｄに配設したレベル計１０より各骨材の貯蔵レベルを受信する（Ｓ１４）。このように受信した骨材貯蔵レベルは操作盤１２の画面上に逐次表示してオペレータが監視しやすいようにする。
【００２４】
また、アスファルト合材の出荷が行われている時には、１バッチ処理分の時間間隔にて骨材貯蔵レベルを測定するようにしている。そこで１バッチ分の混練が完了したか否かを判断し（Ｓ１５）、まだ完了していない場合は混練完了待ちとなり、混練が完了すれば次のステップに移る。先ず、１バッチ分の骨材を払い出したので、骨材貯蔵の予想目標レベルが１バッチ分減少するはずであるからこの分の修正を行う必要がある。
【００２５】
そこで、予測目標レベルから１バッチ分払い出した骨材量に相当するレベル量を差し引き、その値を予測目標レベルとして再設定する（Ｓ１６）。なお、この１バッチ分の骨材払い出しによってどの程度のレベル（％）低下となるかは、予め区画室９ａ〜９ｂ毎、更に好ましくは各区画室９ａ〜９ｂの貯蔵レベルの高さ位置毎に適宜計算して設定しておく。
【００２６】
前記のように、予測目標レベルは出荷中であれば１バッチ毎に修正されて設定されることになる。
【００２７】
次に、ステップＳ１４に進み、各骨材貯蔵レベルの受信を行う。各区画室９ａ〜９ｄより各骨材の貯蔵レベルを受信すると、次に前回分の貯蔵レベルと今回分の貯蔵レベルを比較してその差より各骨材貯蔵ビンの実供給割合の演算を行う（Ｓ１７）。この実供給割合は、前回貯蔵レベル検出時と今回貯蔵レベル検出時の間に各区画室９ａ〜９ｄに実質的に供給された骨材量の割合を示すものである。なお、この間に骨材が払い出されたのであれば、それを考慮して実供給割合を演算する。
【００２８】
この演算された各区画室９ａ〜９ｄへの実供給割合と出荷合材の骨材配合比とを比較し（Ｓ１８）、差があるか否かを判断する（Ｓ１９）。両者に差がある時は出荷合材の使用骨材量に対し特定の骨材の供給が過不足ありということであるので、実供給割合が出荷合材の骨材配合比に近付くように各骨材ホッパ１ａ〜１ｄよりの切り出し割合を補正する（Ｓ２０）。例えば、可変速フィーダ１ａを５％増、可変速フィーダ１ｂを３％減等。なお、どの程度の差異が生ずれば切り出し割合をどの程度補正するかは予め決めておく。また、出荷合材の骨材配合比とは、出荷合材における各種粒径の骨材の構成比であって、その骨材粒径は各区画室９ａ〜９ｄにそれぞれ貯蔵されるものと対応している。
【００２９】
前記のように各区画室９ａ〜９ｄの実供給割合と骨材配合比に差が出るのは、骨材ホッパ１ａ〜１ｄにおける骨材粒度の変動や、また合成供給される骨材の篩い分けが理想通りに行われていないからである。したがって、骨材貯蔵ビン９の各区画室９ａ〜９ｄに出荷合材の骨材配合に見合った骨材量が貯蔵されていくように骨材の切り出し割合の補正量を演算し、速度設定器１７から可変速フィーダ２ａ〜２ｄに対し速度補正を行い、出荷合材に対し各種骨材を過不足なく供給しようとするものである。
【００３０】
なお、骨材の切り出し割合の補正にあたっては、その補正量は次の点に考慮して補正量を決定する。先ず、補正によって骨材の合成粒度が所定の範囲から外れないようにする。また、砂等の割合が多くなり過ぎてドライヤの能力以上の切り出し割合にならないようにする。そして、補正値はオペレータが容易に把握できるように表示装置に表示する等である。
【００３１】
次いで、ステップＳ２１に進んで各骨材の貯蔵レベルが予測目標レベルに達したか否かの判断を行う。またステップ１９において差がない場合はそのままステップＳ２１に進んで各骨材の貯蔵レベルが予測目標レベルに達したか否かの判断を行う。予測目標レベルに達していない場合にはステップＳ１２に戻り、出荷の確認から再度一連の操作を繰り返す。また予測目標レベルに達すると、更に次回の出荷があるか否か判断し（Ｓ２２）、出荷がある場合はステップＳ４に戻って配合内容の受信から一連の操作を繰り返し、出荷がない場合にはＥＮＤに進んで骨材供給を停止する。骨材の供給を停止すれば搬送過程中の骨材が骨材貯蔵ビンに投入された時点で各区画室９ａ〜９ｄは所望の貯蔵レベルに到達する。
【００３２】
このようにして、出荷予定量とその配合比とより各骨材の供給量を演算し、その各骨材供給量より骨材貯蔵ビン９の各区画室９ａ〜９ｄに対する目標となる貯蔵レベルを設定し、アスファルト合材出荷中は１バッチ毎にその目標レベルを更新していく。なお、出荷待ちの状態で骨材供給が行われている時にはその目標レベルは更新されない。そしてレベル計により検出した骨材貯蔵レベルが目標レベルと一致すると骨材の供給を停止するので、出荷に必要な骨材量のみを骨材貯蔵ビン８に供給して貯蔵でき、これによって出荷作業終了後の残材量も少なくなって残材抜き取り作業も短時間にて処理できる。更には特定の骨材の供給過剰もなくて骨材の加熱量も最小限に留めることができて燃費も削減できるのである。
【００３３】
また、骨材貯蔵ビンの各区画室９ａ〜９ｄに分配貯蔵される骨材の貯蔵レベルを検出して実供給割合を演算し、この実供給割合と出荷合材の骨材配合比とを比較し、差があればその差値量に基づく切り出し量の補正を行って各区画室９ａ〜９ｄに貯蔵される骨材量の割合を骨材供給配合比に近づけるように供給制御を行っており、これによって出荷合材に対し適正量の骨材が過不足なく常に供給されることとなり、一部骨材の過小供給による骨材切れを起こすこともなくて運転操作が楽になり、また各骨材の貯蔵量が目標レベルに到達するのがほぼ同時期となって効率の良い骨材供給を行うことができるのである。
【００３４】
なお、本発明においては、各区画室９ａ〜９ｂへ骨材の実供給割合と出荷合材の骨材配合比とを比較して各可変速フィーダ２ａ−２ｄの切り出し割合を補正するようにしているが、これを各区画室９ａ〜９ｂへの骨材の実供給量と、出荷合材の骨材配合比から演算した各骨材の設定供給量を比較して各可変速フィーダ２ａ−２ｄの切り出し量を補正するようにしても単位時間当たりの総骨材供給量がほぼ一定に設定されているので、両者は本質的には同等であり、本発明の技術範囲に属するものである。
【００３５】
【発明の効果】
以上のように本発明に係る請求項１記載の骨材供給制御方法にあっては、骨材貯蔵ビン９の各区画室９ａ〜９ｄに貯蔵量を検出するレベル計１０を配設すると共に、該レベル計１０よりの信号により骨材供給量を制御する骨材供給制御装置１１を備え、予め、出荷しようとするアスファルト合材の出荷予定量とその配合比から各骨材の供給量を演算し、その各骨材供給量より骨材貯蔵ビン９の各区画室９ａ〜９ｄに貯蔵する時に各骨材が到達する目標レベルを演算して設定し、骨材供給中にアスファルト合材の出荷が行われておれば、１バッチ毎に払い出した骨材分の貯蔵レベルを設定した目標レベルより差し引いて目標レベルを更新して再設定し、レベル計１０により検出した骨材貯蔵レベルが前記目標レベルと一致すると骨材ホッパ１ａ〜１ｄよりの骨材の切り出しを停止するようにしたので、出荷しようとするアスファルト合材に必要な骨材量のみを供給して骨材貯蔵ビンに貯蔵でき、出荷終了時には残材として残留する骨材も極力少なくなり、面倒な残材抜き取り作業も短時間にて処理でき、また過剰な骨材を加熱することがなくて燃費節減による省エネルギー化を図ることができる。
【００３６】
また、請求項２記載の骨材供給制御方法にあっては、前記骨材供給中は、所定のタイミング毎に前記レベル計１０によって各区画室９ａ〜９ｄの骨材貯蔵レベルを検出し、検出した前回と今回との骨材貯蔵レベル差と、この間に各区画室９ａ〜９ｄから払い出された骨材量とより各区画室９ａ〜９ｄへの骨材の実供給割合を演算し、該実供給割合と出荷合材の骨材配合比に差異があるならば、出荷合材の各区画室９ａ〜９ｄの骨材使用量に対して特定の区画室への骨材供給に過不足有りと判断し、各区画室９ａ〜９ｄへの骨材の実供給割合が出荷合材の骨材配合比に近付くように可変速フィーダ２ａ〜２ｄの切り出し割合を逐次補正するようにしたので、出荷途中においても出荷合材に対し骨材を過不足なく供給することができ、出荷中に一部骨材の過小供給による骨材切れを起こすこともなく、また各骨材の貯蔵量の目標レベルへの到達がほぼ同時期となって効率の良い骨材供給を行うことができるのである。
【図面の簡単な説明】
【図１】本発明の骨材供給制御方法を採用するアスファルトプラントの概略構成を示す説明図である。
【図２】本発明の骨材供給制御方法の手順を示すフローチャートである。
【図３】本発明の骨材供給制御方法の手順を示すフローチャートである。
【符号の説明】
１ａ〜１ｄ…骨材ホッパー２ａ〜２ｄ…可変速フィーダ
３…引出しコンベヤ４…計量コンベヤ
５…ドライヤ９…骨材貯蔵ビン
９ａ〜９ｄ…区画室１０…レベル計
１１…骨材供給制御装置１２…操作盤[0001]
[Industrial application fields]
The present invention relates to an aggregate supply control method for an asphalt plant that manufactures an asphalt mixture that is a road pavement material.
[0002]
[Prior art]
Generally, in an asphalt plant, the aggregate is cut out at a desired ratio from an aggregate hopper that stores various aggregates for each type, sent to a dryer, which is a heating device, using a bell-conveyor for transporting aggregates, heated by the dryer, and then the upper part of the plant body And is temporarily stored according to particle size in a compartment of an aggregate storage bin disposed below by sieving by particle size with a vibrating sieve. Based on the composition of the asphalt mixture to be manufactured based on the shipping request, aggregates of various particle sizes are dispensed from each compartment, weighed in a predetermined amount, and mixed with other materials such as asphalt by a mixer to manufacture the asphalt mixture are doing.
[0003]
Then, the aggregate supply amount at the time of manufacturing the composite material is controlled by the aggregate scale supplied from the aggregate hopper at a predetermined ratio according to the type of the composite material to be shipped, and by the conveyor scale arranged in the middle of transportation. Is measured, and when the set total aggregate supply amount is reached, the aggregate delivery is controlled to stop.
[0004]
[Problems to be solved by the invention]
However, in the above-described conventional aggregate supply control method, it is possible to supply the total amount of aggregate used for shipping composite, but the aggregate amount distributed and stored in each compartment of the aggregate storage bin is the aggregate amount. Excess or deficiency may occur due to changes in aggregate particle size in the hopper, screen sieving efficiency, clogging and the like. For this reason, a large amount of aggregate may be supplied so that there is no shortage, overflow in some compartments may occur due to excessive supply of aggregate, and a large amount of residual material may remain after shipment is completed. In some cases, it may be necessary to perform annoying remaining material extraction work.
[0005]
In view of the above points, the present invention supplies an appropriate aggregate amount to the aggregate storage bin according to the shipment amount of the asphalt mixture, so that the aggregate remains in the aggregate storage bin as much as possible after the shipment. An object of the present invention is to provide an efficient aggregate supply control method for an asphalt plant.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, the aggregate supply control method according to claim 1 is provided with a level meter for detecting the storage amount in each compartment of the aggregate storage bin, and a signal from the level meter. It is equipped with an aggregate supply control device that controls the aggregate supply amount by means of the above, and when supplying aggregate from the aggregate hopper, the aggregate amount of each asphalt mixture to be shipped is determined in advance from the planned shipment amount and mixing ratio. Calculate the supply amount, calculate the aggregate storage level reached by each aggregate when the calculated aggregate supply amount is supplied to each compartment of the aggregate storage bin, set it as the target level, and supply the aggregate If the asphalt mixture is shipped, the aggregate storage level for one batch is subtracted from the preset target level every time one batch of asphalt mixture is manufactured and shipped, and the target level is reset. Aggregate of each compartment detected by level meter Built level is characterized in that so as to stop the supply of the aggregate upon reaching the target level.
[0007]
The aggregate supply control method according to claim 2, wherein during the aggregate supply, the aggregate storage level of each compartment is detected by the level meter at every predetermined timing, and the previous and current aggregates detected are detected. a storage level difference, calculates the actual feed rate of the aggregate to the aggregate amount more each compartment paid out from the compartment during this time, there is a difference in the aggregate the compounding ratio of the said actual feed rate shipment mixture member Therefore, it is judged that there is an excess or deficiency in the aggregate supply to the specific compartment relative to the aggregate usage of each compartment of the shipping composite , and the actual supply ratio of the aggregate to each compartment is the bone of the shipping composite. The ratio of cutting out of each variable speed feeder was sequentially corrected so as to approach the material mixture ratio, and the aggregate was supplied to each compartment without excess or deficiency with respect to the amount of aggregate used in each compartment of the shipping mixture. It is a feature.
[0008]
[Action]
According to the aggregate supply control method of claim 1 of the present invention, the required aggregate amount is calculated from the planned shipment amount and its blending ratio at the time of aggregate supply, and the aggregate storage bin is calculated from the required aggregate amount. The target level for storage in each compartment is calculated and set. When this target level matches the aggregate storage level detected by the level meter arranged in each compartment, the aggregate supply is stopped. . While shipment is in progress, subtract the aggregate amount for one batch paid out from the aggregate storage bin for each batch from the previously set target level, set the target level again, and detect with the level meter When the aggregate storage level reaches the reset target level, the aggregate supply is stopped. As a result, the amount of aggregate necessary for shipment is supplied, and the aggregate remains as a remaining material in the aggregate storage bin at the end of shipment.
[0009]
Moreover, according to the aggregate supply control method of claim 2, during the aggregate supply, the aggregate storage level of each compartment is detected by a level meter, and from the detected aggregate storage level difference between the previous time and this time The actual supply ratio of aggregate distributed to each compartment by particle size is calculated. And if there is a difference between the actual supply ratio and the aggregate composition ratio of the shipping composite, the cutting rate of the variable speed feeder should be set so that the actual supply ratio of the aggregate to each compartment approaches the aggregate composition ratio of the shipping composite. The correction is made sequentially and the aggregate supply corresponding to the amount of aggregate used in the shipping composite is always performed. As a result, the aggregate can be supplied to the aggregate storage bin without any excess or deficiency even during shipment, so that there is no shortage of aggregate due to insufficient supply of aggregate during shipment, and the storage amount of each aggregate Can reach the target level almost at the same time, and the aggregate can be supplied efficiently.
[0010]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0011]
Reference numerals 1a to 1d denote aggregate hoppers that store aggregates for each type. A predetermined amount of aggregate is cut out by variable speed feeders 2a to 2d, and is a dryer that is an aggregate heating device via a drawer conveyor 3 and a weighing conveyor 4. 5 and heated to a predetermined temperature by hot air from the burner 6 while passing through the dryer 5.
[0012]
The heated aggregate is lifted up to the upper part of the plant main body by the bucket elevator 7, the aggregate is screened according to the particle size by the vibrating sieve 8, and stored in the aggregate storage bin 9 divided into a plurality of insides according to the particle size. 9a to 9d are compartments for storing aggregates according to gravel large, medium gravel, small gravel, and sand particle size, and level meters 10 for detecting the aggregate storage level are arranged in the respective compartments 9a to 9d. are doing. The illustrated level meter is a continuous level meter using a capacitance type level meter, but in addition to this, a load cell is used with the compartment being made independent, and the torque motor type and heat of the non-continuous level meter are also used. The aggregate storage level may be continuously measured by using a large number of transmissions.
[0013]
11 is an aggregate supply control device that controls the cutting of the aggregates of the aggregate hoppers 1a to 1d. The transmission / reception unit 13 transmits and receives data from the level meter 10 and data with the operation panel 12, and the acquired level data. A calculation unit 14 that performs various calculations, a storage unit 15 that stores various data, an input unit 16 that inputs various setting data, and a speed setting unit 17 that sets the speeds of the variable speed feeders 2a to 2d of the aggregate hoppers 1a to 1d. In addition, a control unit 18 that controls each of these elements is provided.
[0014]
The aggregate cut-out control from the aggregate hoppers 1a to 1d is performed by cutting various aggregates at a cut-out ratio corresponding to the aggregate composition of the shipping composite, or for each of the compartments 9a to 9d of the aggregate storage bin 9 The level meter 10 detects the aggregate storage level of each of the compartments 9a to 9d, calculates the aggregate supply ratio and storage amount to each compartment from this aggregate storage level, and feeds back this to determine the aggregate cutting speed. It corrects and supplies the aggregate without excess and deficiency with respect to the aggregate usage of the shipping composite.
[0015]
And the aggregates of various particle sizes stored in the respective compartments 9a to 9d are dispensed from the compartments 9a to 9d to the aggregate measuring tank 19 provided below based on the aggregate composition of the shipping composite, and are measured. The asphalt mixture is manufactured by putting the mixture into the mixer 22 together with the stone powder and molten asphalt measured in the measuring tank 20 and the asphalt measuring tank 21 and mixing them for a predetermined time.
[0016]
Next, a method for controlling the aggregate supply based on the aggregate storage level of the aggregate storage bin 9 will be described with reference to the flowcharts of FIGS. S1 to S22 in the figure indicate steps representing each procedure in the flowchart.
[0017]
First, before starting the operation, the asphalt mixture type and its blending are registered in the operation panel 12 as an initial setting (S1). Further, at the time of supplying the aggregate, the cutout ratio for setting the aggregate cutout speed from each of the aggregate hoppers 1a to 1d corresponding to the type of asphalt composite is registered (S2). And if the aggregate supply amount is set, the cutting speed of each aggregate hopper 1a-1d will be determined from the cutting ratio. It should be noted that the cutting speeds of the aggregate hoppers 1a to 1d may be directly registered in accordance with the cutting ratio of each aggregate determined by the type of asphalt mixture.
[0018]
If the registration is completed, it is determined whether or not to continue the registration for another type of mixture (S3). If the registration is completed, the process proceeds to END to end the registration operation. If the registration is continued, the process returns to step S1 to manufacture. Register for all types of composites.
[0019]
Next, when the operation of the plant is started and the type of mixture to be shipped to the operation panel 12 and the planned shipment amount are input, the aggregate supply control device 11 side receives the content of the shipping mixture via the data transmission / reception unit 13. Then (S4), and then the planned shipping amount is received (S5). When the blending content is received, the cut-out ratios of the respective aggregate hoppers 1a to 1d corresponding to the blending content are read (S6). Moreover, the supply amount of each aggregate required based on the mixing | blending content of a shipping compound material and a shipping scheduled amount is calculated and set (S7). At this time, it is preferable to take into consideration that the supply amount is not insufficient by adding an additional α to the aggregate supply amount obtained by calculation and adding a plus α.
[0020]
When each aggregate supply amount is set, calculation of the target level of aggregate storage of the aggregate storage bin 9 based on each aggregate supply amount is performed (S8). The target level of the aggregate storage bin is an aggregate storage level that each aggregate reaches when each aggregate supply amount is sent to the corresponding compartments 9a to 9d of the aggregate storage bin 9. The aggregate storage level may be expressed as a percentage, with 0% empty and 100% full. In addition, there is no problem if each aggregate supply amount is an amount that can be stored in the corresponding compartments 9a to 9d. However, if the amount is large and overflows when the entire amount is supplied, the storage amount of the compartment is for the time being. 90% of the target level is set as a target level, and if the aggregate is delivered and delivered, the target level is sequentially corrected.
[0021]
Since the target level is the final target storage level to be stored in the aggregate storage bin, the actual aggregate cut-off is the aggregate storage level obtained by subtracting the aggregate amount remaining during the transport process from the target level. It is necessary to stop the cutting of the aggregate when reaching the above. For this reason, a predicted target level is calculated by subtracting the aggregate amount staying in the conveyance process from the target level, and this is set as the target level for aggregate supply control (S9).
[0022]
When the setting of the predicted target level is completed, the aggregate supply can be started. Based on the cutting ratio of each aggregate set by the aggregate supply start switch ON, the cutting speed is commanded from the speed setter 17 to the variable speed feeders 2a to 2d of the aggregate hoppers 1a to 1d. A predetermined amount of aggregate is cut out from the material hoppers 1a to 1d (S10). The transfer timer is started simultaneously with the start of the cutting of the aggregate (S11). This transfer timer sets the time for the cut aggregate to reach the aggregate storage bin 9.
[0023]
When the transfer timer counts up and aggregates cut out from the aggregate hoppers 1a to 1d begin to be supplied to the aggregate storage bin 9, the operation status of the plant is detected and asphalt mixture is shipped (disposal of aggregate). ) Is determined (S12). If the asphalt mixture is not shipped, the aggregate storage level of the aggregate storage bin 9 is gradually increased without discharging the aggregate, and the aggregate storage level is set at a predetermined time interval. It is determined whether or not the measurement timer for measuring in (1) has been counted up, and if it has not been counted up yet, it will wait for counting up, and if it has been counted up, the level meter 10 provided in each of the compartments 9a to 9d. Thus, the storage level of each aggregate is received (S14). The aggregate storage level received in this way is sequentially displayed on the screen of the operation panel 12 so that the operator can easily monitor it.
[0024]
Moreover, when the asphalt mixture is shipped, the aggregate storage level is measured at a time interval corresponding to one batch process. Therefore, it is determined whether or not one batch of kneading has been completed (S15). If it has not been completed, the process waits for the completion of kneading. First, since one batch of aggregate has been dispensed, the expected target level of aggregate storage should be reduced by one batch, so this amount needs to be corrected.
[0025]
Therefore, the level amount corresponding to the aggregate amount paid out for one batch is subtracted from the predicted target level, and the value is reset as the predicted target level (S16). It should be noted that the level (%) of the reduction in the amount of aggregate delivered for one batch is appropriately determined in advance for each compartment 9a to 9b, more preferably for each storage level height position of each compartment 9a to 9b. Calculate and set.
[0026]
As described above, the predicted target level is corrected and set for each batch when shipping.
[0027]
Next, it progresses to step S14 and each aggregate storage level is received. When the storage level of each aggregate is received from each of the compartments 9a to 9d, the storage level for the previous time and the storage level for the current time are compared, and the actual supply ratio of each aggregate storage bin is calculated from the difference ( S17). This actual supply ratio indicates the ratio of the amount of aggregate substantially supplied to each of the compartments 9a to 9d between the previous storage level detection and the current storage level detection. If the aggregate is paid out during this period, the actual supply ratio is calculated in consideration thereof.
[0028]
The calculated actual supply ratio to each of the compartments 9a to 9d is compared with the aggregate composition ratio of the shipping composite (S18), and it is determined whether there is a difference (S19). When there is a difference between the two, it means that there is an excess or deficiency in the supply of specific aggregates relative to the amount of aggregate used in the shipping composite, so each actual supply ratio approaches the aggregate composition ratio of the shipping composite. The cut-out ratio from the aggregate hoppers 1a to 1d is corrected (S20). For example, the variable speed feeder 1a is increased by 5% and the variable speed feeder 1b is decreased by 3%. Note that it is determined in advance how much difference is generated and how much the cutout ratio is corrected. The aggregate composition ratio of the shipping composite is the composition ratio of aggregates of various particle sizes in the shipping composite, and the aggregate particle size corresponds to that stored in each of the compartments 9a to 9d. ing.
[0029]
As described above, the difference in the actual supply ratio and the aggregate blending ratio of the respective compartments 9a to 9d is due to the change in the aggregate particle size in the aggregate hoppers 1a to 1d and the screening of the aggregate to be supplied synthetically. This is because it is not performed as ideal. Accordingly, the correction amount of the aggregate cutting ratio is calculated so that the aggregate amount corresponding to the aggregate composition of the shipping composite is stored in each of the compartments 9a to 9d of the aggregate storage bin 9, and the speed setting unit 17 Therefore, the speed of the variable speed feeders 2a to 2d is corrected so as to supply various aggregates to the shipping composite material without excess or deficiency.
[0030]
When correcting the aggregate cutout ratio, the correction amount is determined in consideration of the following points. First, the aggregate particle size of the aggregate is prevented from deviating from a predetermined range by correction. Also, make sure that the proportion of sand, etc. is not too high, and that it does not exceed the capacity of the dryer. The correction value is displayed on a display device so that the operator can easily grasp it.
[0031]
Next, the process proceeds to step S21 to determine whether or not the storage level of each aggregate has reached the predicted target level. If there is no difference in step 19, the process proceeds to step S21 as it is to determine whether or not the storage level of each aggregate has reached the predicted target level. If the predicted target level has not been reached, the process returns to step S12, and a series of operations are repeated again from the confirmation of shipment. When the predicted target level is reached, it is further determined whether or not there is a next shipment (S22). If there is a shipment, the process returns to step S4 and the series of operations is repeated from the receipt of the blending contents. Proceed to END to stop the aggregate supply. If the supply of the aggregate is stopped, each of the compartments 9a to 9d reaches a desired storage level when the aggregate in the conveying process is put into the aggregate storage bin.
[0032]
In this manner, the supply amount of each aggregate is calculated from the planned shipment amount and its blending ratio, and the target storage level for each of the compartments 9a to 9d of the aggregate storage bin 9 is set from the aggregate supply amount. And during shipment of asphalt mixture, the target level is updated every batch. It should be noted that the target level is not updated when aggregate is being supplied while waiting for shipment. When the aggregate storage level detected by the level meter coincides with the target level, the aggregate supply is stopped, so that only the aggregate amount necessary for shipment can be supplied to the aggregate storage bin 8 and stored. The amount of remaining material after completion is reduced, and the remaining material extraction operation can be processed in a short time. Furthermore, there is no excessive supply of specific aggregates, the amount of heating of the aggregates can be kept to a minimum, and fuel consumption can be reduced.
[0033]
Moreover, the storage level of the aggregate distributed and stored in each of the compartments 9a to 9d of the aggregate storage bin is detected to calculate the actual supply ratio, and the actual supply ratio and the aggregate composition ratio of the shipping composite are compared. If there is a difference, the cutout amount is corrected based on the difference value amount, and the supply control is performed so that the ratio of the aggregate amount stored in each of the compartments 9a to 9d approaches the aggregate supply ratio. As a result, an appropriate amount of aggregate is always supplied without excess or deficiency with respect to the shipping composite, and there is no shortage of aggregate due to insufficient supply of some aggregates, and operation is easy. The storage amount reaches the target level almost at the same time, and efficient aggregate supply can be performed.
[0034]
In the present invention, the actual supply ratio of the aggregate to each of the compartments 9a to 9b is compared with the aggregate mixing ratio of the shipping composite, and the cut-out ratio of each variable speed feeder 2a-2d is corrected. However, this is compared with the actual supply amount of the aggregate to each of the compartments 9a to 9b and the set supply amount of each aggregate calculated from the aggregate mixture ratio of the shipping composite, and each variable speed feeder 2a-2d is cut out Even if the amount is corrected, since the total aggregate supply amount per unit time is set to be substantially constant, both are essentially the same and belong to the technical scope of the present invention.
[0035]
【The invention's effect】
As described above, in the aggregate supply control method according to claim 1 of the present invention, the level meter 10 for detecting the storage amount is disposed in each of the compartments 9a to 9d of the aggregate storage bin 9, and the An aggregate supply control device 11 that controls the aggregate supply amount by a signal from the level meter 10 is provided, and the aggregate supply amount is calculated in advance from the planned shipment amount of the asphalt mixture to be shipped and its blend ratio. The target level reached by each aggregate when it is stored in the respective compartments 9a to 9d of the aggregate storage bin 9 from the aggregate supply amount is calculated and set , and the asphalt mixture is shipped during the aggregate supply. If it has been performed, the storage level of the aggregate dispensed for each batch is subtracted from the set target level, the target level is updated and reset, and the aggregate storage level detected by the level meter 10 is the target level. The aggregate hopper 1a Since the cutting of the aggregate from ~ 1d is stopped, only the amount of aggregate necessary for the asphalt mixture to be shipped can be supplied and stored in the aggregate storage bin, and remains as a remaining material at the end of shipment Aggregates are reduced as much as possible, and troublesome work of extracting remaining materials can be processed in a short time. Also, excessive aggregates are not heated and energy saving can be achieved by reducing fuel consumption.
[0036]
In the aggregate supply control method according to claim 2, during the aggregate supply, the aggregate storage level of each of the compartments 9 a to 9 d is detected and detected by the level meter 10 at every predetermined timing. The actual supply ratio of the aggregate to each of the compartments 9a to 9d is calculated from the difference in the aggregate storage level between the previous time and this time, and the amount of aggregate paid out from each of the compartments 9a to 9d in the meantime. If there is a difference in the aggregate composition ratio of the shipping composite , it is determined that there is an excess or deficiency in the aggregate supply to the specific compartment relative to the aggregate usage of each compartment 9a-9d of the shipping composite, Since the cutting ratio of the variable speed feeders 2a to 2d is sequentially corrected so that the actual supply ratio of the aggregate to each of the compartments 9a to 9d approaches the aggregate mixing ratio of the shipping composite, Aggregate can be supplied to the material without excess and deficiency. It without causing aggregate breakage caused by under-supply of the aggregate, also it is possible to perform good aggregate supply efficiency is almost the same period is reaching the target level of the storage amount of the aggregate.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a schematic configuration of an asphalt plant that employs an aggregate supply control method of the present invention.
FIG. 2 is a flowchart showing a procedure of an aggregate supply control method of the present invention.
FIG. 3 is a flowchart showing a procedure of an aggregate supply control method of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1a-1d ... Aggregate hopper 2a-2d ... Variable speed feeder 3 ... Drawer conveyor 4 ... Metering conveyor 5 ... Dryer 9 ... Aggregate storage bins 9a-9d ... Compartment 10 ... Level meter 11 ... Aggregate supply control device 12 ... Operation board

Claims

骨材を種別毎に貯蔵して可変速フィーダにより切り出し量を自在に制御可能とした骨材ホッパーから所望の割合で骨材を切り出し、加熱装置であるドライヤにより加熱後、プラント本体の骨材貯蔵ビンの各区画室に粒径別に一時貯蔵し、製造するアスファルト合材の配合に基づいて各種粒径の骨材を所定量計量し、ミキサによりアスファルト等の他の材料と共に混合してアスファルト合材を製造するアスファルトプラントにおいて、前記骨材貯蔵ビンの各区画室に貯蔵量を検出するレベル計を配設すると共に、該レベル計よりの信号により骨材供給量を制御する骨材供給制御装置を具備し、骨材ホッパより骨材を供給する時に、予め、出荷しようとするアスファルト合材の出荷予定量と配合比とから各骨材の供給量を演算し、演算した各骨材の供給量を骨材貯蔵ビンの各区画室に供給したときに各骨材が到達する骨材貯蔵レベルを演算して目標レベルとして設定し、骨材供給中にアスファルト合材の出荷が行われておれば、アスファルト合材を１バッチ製造出荷する毎に予め設定した目標レベルより１バッチ分の骨材貯蔵レベルを減算して目標レベルを再設定し、レベル計により検出した各区画室の骨材貯蔵レベルが前記目標レベルに達した時点で骨材の供給を停止するようにしたことを特徴とするアスファルトプラントの骨材供給制御方法。Aggregate is stored for each type, aggregate is cut at a desired ratio from an aggregate hopper whose amount can be controlled freely by a variable speed feeder, heated by a dryer that is a heating device, and then stored in the plant body Temporarily store by grain size in each compartment of the bottle, measure a predetermined amount of aggregate of various particle sizes based on the composition of the asphalt mixture to be manufactured, mix with other materials such as asphalt with a mixer and mix the asphalt mixture In the asphalt plant to be manufactured, a level meter for detecting the storage amount is disposed in each compartment of the aggregate storage bin, and an aggregate supply control device for controlling the aggregate supply amount by a signal from the level meter is provided. When the aggregate is supplied from the aggregate hopper, the aggregate supply amount is calculated from the planned shipment amount and the mixing ratio of the asphalt mixture to be shipped in advance. The supply amount by calculating the aggregate storage levels each bone material reaches when supplied to each compartment of the aggregate storage bin and set as the target level, I is carried out shipment of asphalt mixture into aggregate supply For example, every time one batch of asphalt mixture is manufactured and shipped, subtract the aggregate storage level for one batch from the preset target level, reset the target level, and detect the aggregate storage level of each compartment detected by the level meter. An aggregate supply control method for an asphalt plant, wherein aggregate supply is stopped when the target level reaches the target level.

前記骨材供給中は、所定のタイミング毎に前記レベル計によって各区画室の骨材貯蔵レベルを検出し、検出した前回と今回との骨材貯蔵レベル差と、この間に各区画室から払い出された骨材量とより各区画室への骨材の実供給割合を演算し、該実供給割合と出荷合材の骨材配合比に差異があるならば、出荷合材の各区画室の骨材使用量に対して特定の区画室への骨材供給に過不足有りと判断し、各区画室への骨材の実供給割合が出荷合材の骨材配合比に近付くように各可変速フィーダの切り出し割合を逐次補正して、出荷合材の各区画室の骨材使用量に対して過不足なく各区画室へ骨材を供給するようにしたことを特徴とする請求項１記載のアスファルトプラントの骨材供給制御方法。During the aggregate supply, the aggregate storage level of each compartment is detected by the level meter at every predetermined timing, and the aggregate storage level difference between the previous time and the current time detected and paid out from each compartment in the meantime. calculates the actual feed rate of the aggregate to the aggregate amount more each compartment, if there is a difference in the aggregate the compounding ratio of said actual feed rate and shipping mixture material, aggregate usage of each compartment of the shipping mixture member Therefore, it is judged that there is an excess or deficiency in the aggregate supply to specific compartments, and the cutout ratio of each variable speed feeder is adjusted so that the actual supply ratio of aggregate to each compartment approaches the aggregate composition ratio of the shipping mixture The aggregate supply of the asphalt plant according to claim 1, wherein the aggregate is supplied to each compartment without excess or deficiency with respect to the amount of aggregate used in each compartment of the shipping composite. Control method.