【０００１】
【発明の属する技術分野】
本発明は、油槽内の浄化装置に係り、産業用油槽あるいはＯＦケーブル（油封入ケーブル）用圧力油槽内の油を浄化する油槽内の浄化装置に関するものである。
【０００２】
【従来の技術】
ＯＦケーブル油槽のうちで、ＳＰＴ（特殊圧力油槽）では、近年、外油が著しく劣化し内部のセルに錆が進行していることが確認されている。
【０００３】
上記のＳＰＴは圧縮機を利用した空気加圧式の給油装置であり、図６に示す構成により、セル油槽１４内でセル１６を介して内油１２の圧力すなわちＯＦケーブル１０の絶縁油の圧力を調整して、ＯＦケーブル１０の通電による絶縁油の膨張・収縮を補償する機能を発揮している。
【０００４】
すなわち、空気をＯＦケーブルの絶縁油に直接接しさせて加圧する圧力調整したのでは、絶縁油の劣化など電気的特性の変化に影響を及ぼすため、まず、セル油槽１４内で収縮・膨張可能なセル１６を介することにより、絶縁油（内油１２）を空気と接しさせることなく別の油（外油１８）に圧力伝達し、そして、この別の油を調圧油槽２０において空気加圧して圧力調整することにより、絶縁油の圧力調整をするようにしている。
ＳＰＴの具体的な構成は、図６に示すように、ＯＦケーブル１０の絶縁油通路をセル油槽１４内のセル１６内に通じ（セル１６内の収容油を内油１２という）、セル１６内圧力をＯＦケーブル１０の絶縁油通路と同じ圧力とする。そして、セル油槽１４内には、そのセル１６外周に圧力伝達用の油（外油）１８を収容し、この外油１８を調圧油槽２０に導いている。この調圧油槽２０内では外油１８上層の空気層２２に加圧・圧力制御装置（コンプレッサ２４ａ、高圧タンク２４ｂ、減圧弁２４ｃ）２４から圧力空気が送給され、この圧力空気により、外油１８の圧力を調整できるようになっている。
【０００５】
しかしながら、コンプレッサ２４ａ起動の都度、調圧油槽２０に多量の空気が供給されるので、この空気中の酸素が外油１８自身の成分と反応して酸化劣化させてしまい、油中に水分が発生しセル１６が腐食に至ることが分かっている。したがって、セル油槽の腐食が進行しないように、劣化した外油中の水分や腐食生成物類を除去する必要がある。そのため、セル油槽１４内の劣化した外油を排出または改善するためには、油そのものを入れ替える必要がある。
【０００６】
ＯＦケーブルのセル油槽１４の場合、油の排出または改善の際には、ＯＦケーブル１０の送電を停止した状態で、次の手順で行う。まず、セル油槽内の油量が安定するまでの数時間を作業待機する。その後、タンク上面に位置するフランジを開口し、タンク内の大量の油（外油）をポンプを使用して排出する。タンク内が空になったことを確認して、新油を注入する。タンク内の脱気のため補強枠を施した仮フランジを据え付け、仮フランジを介してタンク内部の真空引きを行う。そして、油量調整後、本フランジを取りつけ、作業を終了する。
【０００７】
しかしながら、前記のセル油槽内の外油の交換方法では、ケーブル送電の停止が必須と成り、大量の廃油処理や費やす労力および時間を要することが課題となる。また、セル油槽の構造が、外油の入れ替えを考慮した設計ではないため、外部に通じるコネクタが極端に少なく作業性が悪い。さらには、油槽本体は密閉型の圧力容器であり、内部の腐食・油の変色などの内部異常を視覚的に確認できないなどの課題がある。
なお、セル油槽も含めて一般に油槽では、種類によって、内部に複雑な構造物を内蔵した構造や、または、圧力制御が必要な構造のものがあり、内部残留した油および残留成分の入れ替えが十分かつ完全にはできないものが存在する。この場合、タンクそのものを交換することになり、多額の費用がかかる。
【０００８】
なお、この種に関する先行技術文献として、外ガス型圧力油槽に関する特許文献１が挙げられる。この特許文献１では、ＯＦケーブル線路において負荷遮断や負荷の急激な油量減少が生じた場合においても、必要な線路油圧を維持できるガス容量をもったＯＦケーブル用外ガス型圧力油槽が開示されている。
【０００９】
【特許文献１】
特開平１０−２０１０７４号公報
【００１０】
【発明が解決しようとする課題】
本発明は、前記従来の問題点を解消するためのものであって、油槽内の油が劣化して交換あるいは浄化の必要なときに、油槽内の構造に拘わらずに、劣化した油槽内の油の効率的な排出あるいは循環浄化を可能にし、したがって、例えばＯＦケーブルの特殊圧力油槽であってもケーブルの送電を止めることなく外油の循環浄油を可能にする、油槽内の浄化装置を提供することを目的としている。
【００１１】
【課題を解決するための手段】
本発明は、上部に油の入り口を設け、下部に油の出口を設けた油槽内の浄化装置であって、下部の油の出口から油槽内の油を排出可能状態として上部の油の入り口から油槽内に清浄な油を送り込む送油部と、前記油槽内に送り込む清浄な油の温度を油槽内に収容されている油の温度よりも高くする加熱部を油送り込み経路に設けたことを特徴とする油槽内の浄化装置である。
本発明によれば、油槽内に上部から送り込む清浄な油が既に油槽内にある油よりも温度が高く比重が軽いので、入り込む油が油槽内の油と交じり合わずに油槽内に上方に溜まり、その溜まる油量が徐々に増えて行き圧力が高くなり、この圧力により油槽内の油が下方に押されて下部の出口から押し出される。したがって、油槽内の油を大量であったとしても作業性良く交換・浄化できる。また、上部開口から入った油で内部の油を押し出して交換出来るので、油槽内の圧力を加えたままで油の交換・浄化ができるので、例えばＯＦケーブルのＳＰＴ（特殊圧力油槽）であっても、運転中の加圧下でも油の交換・浄化ができ、作業性が高い。また、温度の高い比重の軽い油を上部入り口から押し入れるので、油槽内の複雑な内部構造でも細部で押し込んだ油と既存の油とが混じりあいにくく、油の完全な交換・浄化を簡単な作業で行える。なお、上部の入り口から入れる油は浄化した油でも新油でも本発明の範囲内である。
なお、加熱部で加熱する清浄油の槽内油との温度差は、７〜１０℃が好ましい。
【００１２】
なお、本発明においては、下部の油の出口から排出される油を浄化し、浄化した油を上部の油の入り口から清浄な油として送油部から送り込み可能にした油浄化部を有したことが好適である。これにより、排出された油を油浄化部で浄化した後に清浄な油として循環使用でき、新しい油の使用を少なくできる。なお、浄化部は例えば活性アルミナ（Ａｌ２Ｏ３）を主成分とする吸着用フィルタを使用することが好ましく、活性アルミナで劣化した油中の水分や腐食生成物を十分に除去できる。
また、本発明においては、浄化部への油の入側と出側をバイパスバルブを開くことにより連通可能にするバイパス通路を設け、バイパスバルブを開けてバイパス通路を介して油を浄化部で繰り返し循環可能にすることが好適である。これにより、繰り返し浄化部に循環して一回では除去できない油中の水分や腐食生成物を十分かつ完全に除去できる。
また、本発明によっては、下部の油の出口から排出された油を油浄化部に通して上部の油の入り口から油槽内に清浄な油を送り込んで油槽内の油を浄化した後に、油槽の上部から油を抜き出しこの抜き出した油を油槽の下部から送り込んで、油槽内の油を撹拌する撹拌手段を設け、撹拌後に再度油槽内の油を浄化するようにしたことが好適である。これにより、油槽内の油を浄化後に、油槽内の部分に残留した水分や腐食生成物などがあってもこの撹拌することにより混じりあい、再度油の浄化をおこなうことにより、完全に油から除去できる。
また、本発明は、ＯＦケーブルのセル油槽に適用するのが好ましいが、その他、一般的な油槽の油交換や浄化に用いるのももちろん好適である。
【００１３】
【発明の実施の形態】
以下、図面を参照して本発明の実施の形態を説明する。
【００１４】
本発明の実施形態は、ＯＦケーブル用のセル油槽に浄化装置にかかるものであり、図１は、本実施形態における浄化装置の全体図を油経路とともに示すものである。前記した図と同様部分に同一の番号を付している。この実施形態の浄化装置は、例えば図６に示した空気加圧式の給油装置（ＳＰＴ）に適用して実施するものであり、図１では、ＯＦケーブル、調圧油槽は図示を省略して、セル油槽１４周りの浄化装置を中心に図示している。
【００１５】
図１に示すように、セル油槽１４は、その内部に複数のセル１６を横方向に配列設置した概略ドラム形状を呈しており、上部（最上部が好ましい）に油の入り口３０ａを設け、底に近い側部下部に油の出口３０ｂを設けたセル油槽１４内の油を浄化する装置である。
下部の油の出口３０ｂにはそれを開閉する元バルブ３２ｂが設けられ、この元バルブ３２ｂを開けることにより出口３０ｂからセル油槽１４内の油を排出可能状態として、上部の油の入り口３０ａから油槽内に清浄な油を送り込む送油部３４と、前記セル油槽１４内に送り込む清浄な油の温度をセル油槽１４内に収容されている油の温度よりも高くする加熱部３６を油送り込み経路３８に設けたものである。加熱部３６は入り口３０ａ付近の送り込み経路の管路に温度調整用のヒータを設置したものであり、セル油槽１４に送り込む清浄な油を目標設定温度に制御可能になっている。この加熱部３６は、入り口３０ａの近傍に設けた方が温度制御を効率的に行えるので好ましい。
【００１６】
詳細には、油送り込み経路３８上には、下部出口３０ｂの元バルブ３２ｂに繋いだ管路が緊急遮断電磁弁４０ａと、送油部３４としての循環ポンプ３４ａと、流量計４２と、浄化部４４としての活性アルミナからなる吸着用フィルタと緊急遮断電磁弁４０ｂとが設けられる。
このようにして、セル油槽１４内に下部の油の出口３０ｂから排出される油を浄化部４４で浄化し、浄化した油を上部の油の入り口３０ａから清浄な油として送油部３４から送り込み可能にした油浄化部４４を有している。
【００１７】
また浄化部４４への油の入側と出側をバイパスバルブ４６を開くことにより連通可能にするバイパス通路４８を設け、バイパスバルブ４６を開けてバイパス通路４８を介して油を浄化部４４で繰り返し循環可能にする。
なお、前記緊急遮断電磁弁４０ａ、４０ｂ、循環ポンプ３４ａには、制御警報盤５０からの信号で作動する。この制御警報盤５０には、警報機付きの連成計へ信号を出力するようになっている。
【００１８】
実施形態では、油槽内に上部から送り込む清浄な油が油槽内の油よりも温度が高く比重が軽いので、油槽内の油と交じり合わずに油槽内に上方から入り込み、これにより、油槽内の油が下部の出口から押し出される。温度の高い比重の軽い油を上部入り口から押し入れるので、油槽内の複雑な内部構造でも細部で押し込んだ油と既存の油とが混じりあいにくく、油の完全な交換・浄化を簡単な作業で行える。
【００１９】
発明者は、本発明の有用性を確認すべく、セル油槽に送り込む油を加熱せずに交換浄化した従来装置と、セル油槽に送り込む油を加熱する本発明装置とを比較検証した。
検証の結果、実機およびモデルについて検証した結果、従来装置で浄油すると図２に示すように、セル油槽１４の上側の入り口３０ａから入った油がセル１６の存在などで出口３０ｂに向かう部分的な特定の流路（パス）を形成してしまい、特定の流路５２周辺の油が流れ出て置換され（改善域５２）浄化されるが、それ以外の流路がセル１６で影響されて油は流れず置換されず（未改善域５４）、浄油効率が非常に悪かったことを確認した。これは、セル油槽１４内のセルやスペーサなどの複雑な形状であり、前記の特定の流路（パス）が形成されることが原因であると判明した。
【００２０】
そこで、本発明では、本発明装置で浄油し加熱して比重差を付けて上側の入り口３０ａから浄油を入れると、図３の（ａ）に示すように、セル油槽１４内に上部から送り込む清浄な油がすでにセル油槽内に入っている油よりも温度が高く比重が軽いので、油槽内の油と交じり合わずに油槽内の上方に溜まり、その溜まる油量が増えて行き、これにより、油槽内の油に下方に向けて圧力が加わり下部の出口３０ｂから押し出され、セル油槽１４内の油が完全に置換できた。したがって、油槽内の油を大量であったとしても作業性良く交換・浄化できることが分かった。
【００２１】
また、下部の油の出口３０ｂから排出された油を油浄化部に通して上部の油の入り口３０ａからセル油槽１４内に清浄な油を送り込んでセル油槽内の油を浄化した後に、図３（ｂ）に示すように、送油部３４の循環ポンプを逆転させて、セル油槽１４の上部の入口３０ａから油を抜き出しこの抜き出した油を油槽の下部の出口３０ｂから送り込んで、セル油槽１４内の油を撹拌する（撹拌手段に相当）。そして、撹拌後に再度油槽内の油を浄化するようにすることが望ましい。これにより、油槽内の油を浄化後に、油槽内の部分に残留した水分や腐食生成物などがあってもこの撹拌することにより混じりあい、再度油の浄化をおこなうことにより、完全に油から除去できる。
【００２２】
ＳＰＴ全体の具体的な浄油手順は、図４に示すように、まず、図示しない調圧油槽を清掃し（手順１）、そのセル油槽１４内の油を図３（ａ）のように正方向つまり加熱した油を入り口３０ａから入れて出口３０ｂからの排油を浄化して循環させて清浄化する（手順２）。
【００２３】
そして、図３（ｂ）のように逆に撹拌して（逆循環させて）（手順３）、循環回数が何回になったかを判断する（手順４）。この循環回数は油槽の大きさ、油中水分量より決定することが好ましい。
【００２４】
そして、油を分析し（油中の水分量）（手順５）、水分量が例えば５０ｐｐｍ以下、好ましくは９０ｐｐｍ×０．５（裕度）＝４５ｐｐｍになるまで（手順６）上記の清浄化の手順１〜４を繰り返す。なお、９０ｐｐｍは油中飽和水分量である。
【００２５】
図５は、具体的なセル油槽について、上記図４の手順にて浄化した結果の油中水分量を検出した結果である。この場合、当初、油槽内の油の平均水分量が１３０ｐｐｍと想定した。外油量が約１４７０リットルであり、浄化した油（上油）の加温時には油槽内の油（下油）より７〜８℃高く加温しており、加温循環は９．５時間行い槽内の油を１．５巡させた。この際に外油の約８０％が効率的に排出され浄化後に戻された。
【００２６】
そして、循環停止を３日間行った後、撹拌を１．５時間行った。この場合、循環停止時には、油槽下部に残っている水分の多い油、および調整油槽から移動してきた水分の多い油の影響で平均の水分量が増えている。油槽内平均水分量が８０ｐｐｍあった。
【００２７】
そして、再度、加温循環を６時間行い槽内の油を１巡させた。その後、１時間撹拌した後、加温循環は３．５時間行い槽内の油を０．５巡させた。終了後、槽内平均水分量が３２ｐｐｍであった。
このように、上記の油槽内の油に対して循環を３回撹拌２回行うことにより（循環運転時間の合計約２３．５時間（約４日間の内）水分減少率７５％（１３０ｐｐｍから３２ｐｐｍに減少）であり、１巡目の循環（加熱循環）で約８０％の油が効率的に排出された。１巡目終了後、油槽上下の水分量に差が発生したが、撹拌によりその差が縮まった。撹拌により油槽全体の水分量がほぼ均一になることが確認された。２回目の撹拌が終了した時点で、十分な浄油効果が得られた。全体的に、当初油槽内平均水分量が平均１３０ｐｐｍあったものを、本発明装置で浄化後３２ｐｐｍとなり、加熱循環から撹拌へそして加熱循環することにより、槽内油を高い能力で清浄化できたことが理解される。
【００２８】
なお、上記の浄化のための加温循環、撹拌循環、循環停止などの作業時間や回数は一例であって、油槽構造や水分量などの各種条件に応じて適切に変更設定できる。
また、本発明で浄化する油槽は、セル油槽がもっとも好ましい、その他の一般用産業機器の油槽内の浄化に用いることももちろんである。
【００２９】
【発明の効果】
以上のように本発明によれば、油槽内の油を大量であったとしても作業性良く交換・浄化できる。また、上部開口から入った油で内部の油を押し出して交換出来るので、油槽内の圧力を加えたままで油の交換・浄化が可能であり、例えばＯＦケーブルのＳＰＴ（特殊圧力油槽）であっても、運転中の加圧下でも油の交換・浄化ができ、作業性が高い。また、温度の高い比重の軽い油を上部入り口から押し入れるので、油槽内の複雑な内部構造でも細部で押し込んだ油と既存の油とが混じりあいにくく、油の完全な交換・浄化を簡単な作業で行える。
【００３０】
なお、本発明においては、下部の油の出口から排出される油を浄化し、浄化した油を上部の油の入り口から清浄な油として送油部から送り込み可能にした油浄化部を有したことにすれば、排出された油を油浄化部で浄化した後に清浄な油として循環使用でき、新しい油の使用を少なくできる。
また、本発明においては、浄化部への油の入側と出側をバイパスバルブを開くことにより連通可能にするバイパス通路を設け、バイパスバルブを開けてバイパス通路を介して油を浄化部で繰り返し循環可能にすることにより、繰り返し浄化部に循環して一回では除去できない油中の水分や腐食生成物を十分かつ完全に除去できる。
【００３１】
また、本発明においては、下部の油の出口から排出された油を油浄化部に通して上部の油の入り口から油槽内に清浄な油を送り込んで油槽内の油を浄化した後に、油槽の上部から油を抜き出しこの抜き出した油を油槽の下部から送り込んで、油槽内の油を撹拌する撹拌手段を設け、撹拌後に再度油槽内の油を浄化するようにしたことにより、油槽内の油を浄化後に、油槽内の部分に残留した水分や腐食生成物などがあってもこの撹拌することにより混じりあい、再度油の浄化をおこなうことにより、完全に油から除去できる等の効果を奏する。
【図面の簡単な説明】
【図１】本発明に係る実施形態をセル油槽の外油の浄化装置示す一部断面図を含む配管図である。
【図２】従来装置で浄油中の油に特定の流路の形成される概念説明図である。
【図３】（ａ）、（ｂ）はセル油槽の加温循環と逆方向の循環（撹拌）の流路を模式的に示す説明図である。
【図４】本実施例装置による具体的によ浄油手順を示すフロー図である。
【図５】セル油槽の浄化結果の説明図である。
【図６】従来の浄油装置を用いたＯＦケーブルの外油の浄化装置の説明図である。
【符号の説明】
１０ ＯＦケーブル
１２ 内油
１４ セル油槽
１６ セル
１８ 外油
３０ａ 入り口
３０ｂ 出口
３２ａ、３２ｂ 元バルブ
３４ 送油部
３６ 加熱部
３８ 油送り込み経路
４０ａ、４０ｂ 緊急遮断電磁弁
４２ 流量計
４４ 浄化部
４６ バイパスバルブ
４８ バイパス通路[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a purification device in an oil tank, and more particularly to a purification device in an oil tank for purifying oil in an industrial oil tank or a pressure oil tank for an OF cable (oil-filled cable).
[0002]
[Prior art]
Of the OF cable oil tanks, in SPT (special pressure oil tanks), in recent years, it has been confirmed that the outer oil has significantly deteriorated and rust has progressed in the internal cells.
[0003]
The SPT is an air pressurized oil supply device using a compressor. The configuration shown in FIG. 6 reduces the pressure of the internal oil 12, that is, the pressure of the insulating oil of the OF cable 10 through the cell 16 in the cell oil tank 14. By adjusting, the function of compensating for the expansion and contraction of the insulating oil due to the energization of the OF cable 10 is exhibited.
[0004]
That is, if the pressure is adjusted such that the air is brought into direct contact with the insulating oil of the OF cable and the pressure is adjusted, the change in the electrical characteristics such as the deterioration of the insulating oil is affected. Through the cell 16, the pressure of the insulating oil (inner oil 12) is transmitted to another oil (outer oil 18) without contact with air, and the other oil is air-pressurized in the pressure adjusting oil tank 20. By adjusting the pressure, the pressure of the insulating oil is adjusted.
As shown in FIG. 6, the specific configuration of the SPT is such that the insulating oil passage of the OF cable 10 is connected to the cell 16 in the cell oil tank 14 (the oil contained in the cell 16 is referred to as the internal oil 12). The pressure is the same as that of the insulating oil passage of the OF cable 10. In the cell oil tank 14, oil (external oil) 18 for transmitting pressure is stored on the outer periphery of the cell 16, and the external oil 18 is guided to the pressure regulating oil tank 20. In the pressure regulating oil tank 20, pressurized / pressure control devices (compressor 24a, high pressure tank 24b, pressure reducing valve 24c) 24 supply compressed air to the air layer 22 above the outer oil 18, and the compressed air The pressure of 18 can be adjusted.
[0005]
However, a large amount of air is supplied to the pressure regulating oil tank 20 every time the compressor 24a is started, so that oxygen in the air reacts with the components of the outer oil 18 itself to cause oxidative deterioration, and water is generated in the oil. It has been found that the cell 16 leads to corrosion. Therefore, it is necessary to remove moisture and corrosion products in the deteriorated outer oil so that the corrosion of the cell oil tank does not progress. Therefore, in order to discharge or improve the deteriorated outer oil in the cell oil tank 14, it is necessary to replace the oil itself.
[0006]
In the case of the cell oil tank 14 of the OF cable, when discharging or improving the oil, the power transmission of the OF cable 10 is stopped and the following procedure is performed. First, the operation waits for several hours until the amount of oil in the cell oil tank is stabilized. Thereafter, the flange located on the upper surface of the tank is opened, and a large amount of oil (outside oil) in the tank is discharged using a pump. Make sure that the tank is empty and fill it with new oil. A temporary flange provided with a reinforcing frame is installed for deaeration of the tank, and the inside of the tank is evacuated via the temporary flange. After the oil amount is adjusted, the flange is attached, and the operation is completed.
[0007]
However, in the above-described method of replacing the external oil in the cell oil tank, it is necessary to stop the power transmission of the cable, and there is a problem that a large amount of waste oil processing and labor and time are required. Further, since the structure of the cell oil tank is not designed in consideration of the replacement of the external oil, the number of connectors leading to the outside is extremely small, and the workability is poor. Furthermore, the main body of the oil tank is a closed type pressure vessel, and there is a problem that internal abnormalities such as internal corrosion and discoloration of oil cannot be visually confirmed.
In general, depending on the type of oil tank including the cell oil tank, there is a structure with a built-in complex structure or a structure that requires pressure control, and the replacement of oil and residual components remaining inside is sufficient. And there are things that cannot be completely done. In this case, the tank itself needs to be replaced, which costs a lot of money.
[0008]
As a prior art document relating to this type, there is Patent Document 1 relating to an external gas type pressure oil tank. Patent Document 1 discloses an outer gas pressure oil tank for an OF cable having a gas capacity capable of maintaining a required line oil pressure even when a load interruption or a sudden decrease in the oil amount of the load occurs in the OF cable line. ing.
[0009]
[Patent Document 1]
JP-A-10-201074
[Problems to be solved by the invention]
The present invention has been made to solve the above-mentioned conventional problems, and when the oil in the oil tank is deteriorated and needs to be replaced or purified, regardless of the structure in the oil tank, the oil in the deteriorated oil tank is reduced. A purifying device in an oil tank that enables efficient drainage or circulating purification of oil, and thus enables circulating oil purification of external oil without stopping power transmission of a cable even in a special pressure oil tank of an OF cable, for example. It is intended to provide.
[0011]
[Means for Solving the Problems]
The present invention is a purification device in an oil tank in which an oil inlet is provided in an upper portion and an oil outlet is provided in a lower portion, wherein the oil in the oil tank can be discharged from the lower oil outlet so that the oil in the oil tank can be discharged from the upper oil inlet. An oil feeding section for feeding clean oil into the oil tank and a heating section for increasing the temperature of the clean oil fed into the oil tank higher than the temperature of the oil contained in the oil tank are provided in the oil feeding path. It is a purification device in the oil tank.
According to the present invention, since the temperature of the clean oil fed from the upper portion into the oil tank and the specific gravity thereof are lower than those of the oil already in the oil tank, the oil entering the oil tank is accumulated upward in the oil tank without intermingling with the oil in the oil tank. The amount of accumulated oil gradually increases, and the pressure increases. This pressure causes the oil in the oil tank to be pushed downward and pushed out from the lower outlet. Therefore, even if the amount of oil in the oil tank is large, it can be exchanged and purified with good workability. Also, since the oil inside can be pushed out and replaced with the oil that has entered through the upper opening, the oil can be exchanged and purified while the pressure in the oil tank is being applied. For example, even if the SPT (special pressure oil tank) of an OF cable is used, Oil can be exchanged and purified even under pressure during operation, and workability is high. In addition, since light oil with high specific gravity and high temperature is pushed in from the upper entrance, even if the internal structure inside the oil tank is complicated, the oil pushed in in detail and the existing oil are difficult to mix, and complete replacement and purification of the oil is easy. Can be done by work. It should be noted that the oil supplied from the upper inlet is either purified oil or new oil within the scope of the present invention.
The temperature difference between the clean oil heated in the heating unit and the oil in the tank is preferably 7 to 10 ° C.
[0012]
In the present invention, an oil purifying unit that purifies oil discharged from an outlet of a lower oil and allows the purified oil to be sent from an oil feeding unit as clean oil from an inlet of an upper oil is provided. Is preferred. As a result, the discharged oil can be circulated and used as clean oil after being purified by the oil purification section, and the use of new oil can be reduced. The purifying section preferably uses, for example, an adsorption filter mainly composed of activated alumina (Al 2 O 3 ), and can sufficiently remove moisture and corrosion products in oil degraded by activated alumina.
Further, in the present invention, a bypass passage is provided to enable communication between an inlet and an outlet of oil to the purifying section by opening a bypass valve, and the bypass valve is opened, and oil is repeatedly passed through the bypass passage at the purifying section. Preferably, it is recyclable. This makes it possible to satisfactorily and completely remove water and corrosion products in the oil that cannot be removed once by circulating through the purification section.
Also, according to the present invention, the oil discharged from the lower oil outlet is passed through the oil purifier to feed clean oil into the oil tank from the upper oil inlet to purify the oil in the oil tank, and then the oil tank is cleaned. It is preferable that an oil is extracted from the upper part, the extracted oil is sent from the lower part of the oil tank, and a stirring means for stirring the oil in the oil tank is provided, and after the stirring, the oil in the oil tank is purified again. As a result, after purifying the oil in the oil tank, even if there is residual moisture or corrosion products in the oil tank, they are mixed by this stirring, and the oil is completely removed by purifying the oil again. it can.
In addition, the present invention is preferably applied to a cell oil tank of an OF cable, but is of course also suitably used for oil exchange and purification of a general oil tank.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0014]
The embodiment of the present invention relates to a purification device in a cell oil tank for an OF cable, and FIG. 1 shows an overall view of the purification device in this embodiment together with an oil path. The same parts as those in the above-mentioned drawings are denoted by the same reference numerals. The purifying device of this embodiment is applied to, for example, an air pressurized oil supply device (SPT) shown in FIG. 6. In FIG. 1, an OF cable and a pressure regulating oil tank are omitted from illustration. The figure mainly illustrates a purification device around the cell oil tank 14.
[0015]
As shown in FIG. 1, the cell oil tank 14 has a general drum shape in which a plurality of cells 16 are arranged in a horizontal direction, and an oil inlet 30a is provided at an upper portion (preferably the uppermost portion). This is a device for purifying oil in a cell oil tank 14 provided with an oil outlet 30b at a lower portion on the side close to.
The lower oil outlet 30b is provided with a base valve 32b for opening and closing the lower oil outlet 30b. By opening the base valve 32b, the oil in the cell oil tank 14 can be discharged from the outlet 30b. An oil feeding section 34 for feeding clean oil into the inside and a heating section 36 for making the temperature of the clean oil fed into the cell oil tank 14 higher than the temperature of the oil contained in the cell oil tank 14 through an oil feeding path 38. It is provided in. The heating unit 36 is provided with a heater for adjusting temperature in a pipe of a feeding path near the entrance 30a, and can control clean oil fed into the cell oil tank 14 to a target set temperature. The heating unit 36 is preferably provided near the entrance 30a because the temperature control can be performed efficiently.
[0016]
Specifically, on the oil feed path 38, a pipe line connected to the main valve 32b of the lower outlet 30b is provided with an emergency shutoff solenoid valve 40a, a circulation pump 34a as an oil feed section 34, a flow meter 42, and a purification section. An adsorption filter 44 made of activated alumina and an emergency shutoff solenoid valve 40b are provided.
In this manner, the oil discharged from the lower oil outlet 30b into the cell oil tank 14 is purified by the purifier 44, and the purified oil is sent from the oil feeder 34 as clean oil from the upper oil inlet 30a. It has an enabled oil purification section 44.
[0017]
Further, a bypass passage 48 is provided to enable communication between the oil inlet side and the oil outlet side by opening the bypass valve 46, and the bypass valve 46 is opened, and the oil is repeated by the purifier 44 via the bypass passage 48. Enable circulation.
The emergency shutoff solenoid valves 40a and 40b and the circulation pump 34a are operated by a signal from the control and warning panel 50. The control alarm panel 50 outputs a signal to a compound meter equipped with an alarm.
[0018]
In the embodiment, since the temperature of the clean oil fed from the top into the oil tank is higher than the oil in the oil tank and the specific gravity is light, the clean oil enters the oil tank from above without intermingling with the oil in the oil tank, and thereby, the inside of the oil tank Oil is forced out of the lower outlet. Light oil with high specific gravity is pushed in from the upper entrance, so even if the internal structure inside the oil tank is complicated, the oil that has been pushed in with the details is difficult to mix with the existing oil, and complete replacement and purification of the oil can be easily performed. I can do it.
[0019]
In order to confirm the usefulness of the present invention, the inventor compared and verified a conventional device that exchanged and purified the oil fed into the cell oil tank without heating it, and a device according to the present invention that heated the oil fed into the cell oil tank.
As a result of the verification, as a result of verification of the actual machine and the model, when oil is purified by the conventional apparatus, as shown in FIG. 2, the oil entering from the upper inlet 30 a of the cell oil tank 14 partially goes to the outlet 30 b due to the presence of the cell 16. A specific flow path (path) is formed, and the oil around the specific flow path 52 flows out and is replaced (improved area 52) to be purified. Did not flow and was not replaced (the unimproved area 54), and it was confirmed that the oil purification efficiency was extremely poor. This is a complicated shape such as a cell and a spacer in the cell oil tank 14, and it has been found that the specific flow path (path) is formed.
[0020]
Therefore, in the present invention, when the oil is purified by the device of the present invention and heated to give a specific gravity difference and the purified oil is introduced from the upper entrance 30a, as shown in FIG. The temperature of the clean oil to be sent is higher and the specific gravity is lower than that of the oil already in the cell oil tank, so it accumulates above the oil tank without intermingling with the oil in the oil tank, and the amount of accumulated oil increases. As a result, the oil in the oil tank was pressed downward and was pushed out from the lower outlet 30b, and the oil in the cell oil tank 14 was completely replaced. Therefore, it was found that even if a large amount of oil in the oil tank was used, the oil could be exchanged and purified with good workability.
[0021]
Further, after the oil discharged from the lower oil outlet 30b is passed through the oil purifier, clean oil is fed into the cell oil tank 14 from the upper oil inlet 30a to purify the oil in the cell oil tank. As shown in (b), the circulating pump of the oil feed unit 34 is reversed to extract oil from the upper inlet 30a of the cell oil tank 14 and feed the extracted oil from the lower outlet 30b of the oil tank to the cell oil tank 14 The oil inside is stirred (corresponding to stirring means). It is desirable to purify the oil in the oil tank again after the stirring. As a result, after purifying the oil in the oil tank, even if there is residual moisture or corrosion products in the oil tank, they are mixed by this stirring, and the oil is completely removed by purifying the oil again. it can.
[0022]
As shown in FIG. 4, a specific oil purification procedure for the entire SPT is as follows. First, a pressure regulating oil tank (not shown) is cleaned (procedure 1), and the oil in the cell oil tank 14 is corrected as shown in FIG. The direction, that is, the heated oil is introduced from the inlet 30a, and the drained oil from the outlet 30b is purified and circulated to purify (procedure 2).
[0023]
Then, as shown in FIG. 3 (b), the mixture is stirred in reverse (reversely circulated) (procedure 3) to determine the number of circulations (procedure 4). The number of circulations is preferably determined based on the size of the oil tank and the water content in the oil.
[0024]
Then, the oil is analyzed (moisture content in the oil) (procedure 5), and the water content is, for example, 50 ppm or less, preferably 90 ppm × 0.5 (margin) = 45 ppm (procedure 6). Repeat steps 1-4. Note that 90 ppm is the saturated water content in oil.
[0025]
FIG. 5 shows the result of detecting the water content in oil as a result of purifying the specific cell oil tank by the procedure of FIG. In this case, it was initially assumed that the average water content of the oil in the oil tank was 130 ppm. The amount of external oil is about 1470 liters, and when the purified oil (upper oil) is heated, it is heated 7-8 ° C higher than the oil in the oil tank (lower oil), and the heating circulation is performed for 9.5 hours. The oil in the tank was cycled 1.5 times. At this time, about 80% of the external oil was efficiently discharged and returned after purification.
[0026]
Then, after the circulation was stopped for 3 days, the stirring was performed for 1.5 hours. In this case, when the circulation is stopped, the average amount of water increases due to the effect of the oil remaining in the lower part of the oil tank and the oil moving from the adjusting oil tank. The average water content in the oil tank was 80 ppm.
[0027]
Then, heating circulation was performed again for 6 hours, and the oil in the tank was cycled once. Then, after stirring for 1 hour, heating circulation was performed for 3.5 hours, and the oil in the tank was circulated 0.5 times. After completion, the average water content in the tank was 32 ppm.
In this way, by circulating the oil in the above oil tank three times and stirring it twice (for a total of about 23.5 hours of circulation operation time (of about 4 days), the water reduction rate is 75% (from 130 ppm to 32 ppm). Approximately 80% of the oil was efficiently discharged in the first cycle (heating circulation) .After the first cycle, there was a difference in the amount of water above and below the oil tank. It was confirmed that the water content of the entire oil tank became almost uniform by stirring, and a sufficient oil-purifying effect was obtained when the second stirring was completed. The average water content was 130 ppm on average, and was 32 ppm after purification by the apparatus of the present invention. It is understood that the oil in the tank could be cleaned with high performance by changing from heating circulation to stirring and heating circulation.
[0028]
The operation time and the number of times of the heating circulation, the stirring circulation, the circulation stop, and the like for the above-described purification are merely examples, and can be appropriately changed and set according to various conditions such as the oil tank structure and the amount of water.
The oil tank to be purified in the present invention is most preferably a cell oil tank. Of course, it can be used for purification in oil tanks of other general industrial equipment.
[0029]
【The invention's effect】
As described above, according to the present invention, even if the amount of oil in the oil tank is large, it can be exchanged and purified with good workability. Also, since the oil inside can be pushed out and replaced with the oil that has entered through the upper opening, the oil can be exchanged and purified while the pressure in the oil tank is being applied. For example, the SPT (special pressure oil tank) of an OF cable can be used. In addition, oil can be exchanged and purified even under pressure during operation, and workability is high. In addition, since light oil with high specific gravity and high temperature is pushed in from the upper entrance, even if the internal structure inside the oil tank is complicated, the oil pushed in in detail and the existing oil are difficult to mix, and complete replacement and purification of the oil is easy. Can be done by work.
[0030]
In the present invention, an oil purifying unit that purifies oil discharged from an outlet of a lower oil and allows the purified oil to be sent from an oil feeding unit as clean oil from an inlet of an upper oil is provided. According to this, the discharged oil can be circulated and used as clean oil after being purified by the oil purification section, and the use of new oil can be reduced.
Further, in the present invention, a bypass passage is provided to enable communication between an inlet and an outlet of oil to the purifying section by opening a bypass valve, and the bypass valve is opened, and oil is repeatedly passed through the bypass passage at the purifying section. By enabling circulation, moisture and corrosion products in oil which cannot be removed by one cycle by repeatedly circulating to the purification section can be sufficiently and completely removed.
[0031]
Further, in the present invention, the oil discharged from the lower oil outlet is passed through the oil purifier to feed clean oil into the oil tank from the upper oil inlet to purify the oil in the oil tank. By extracting the oil from the upper part, feeding the extracted oil from the lower part of the oil tank, and providing a stirring means for stirring the oil in the oil tank, and purifying the oil in the oil tank again after stirring, the oil in the oil tank is removed. After the purification, even if there is moisture or corrosion products remaining in the portion in the oil tank, they are mixed by this stirring, and by purifying the oil again, it is possible to completely remove the oil from the oil.
[Brief description of the drawings]
FIG. 1 is a piping diagram including a partial cross-sectional view showing a device for purifying external oil of a cell oil tank according to an embodiment of the present invention.
FIG. 2 is a conceptual explanatory view in which a specific flow path is formed in oil during oil purification in a conventional apparatus.
FIGS. 3A and 3B are explanatory views schematically showing flow paths of circulation (stirring) in a direction opposite to the heating circulation of the cell oil tank.
FIG. 4 is a flowchart showing a specific oil purification procedure by the apparatus of the present embodiment.
FIG. 5 is an explanatory diagram of a purification result of a cell oil tank.
FIG. 6 is an explanatory view of a conventional apparatus for purifying oil outside an OF cable using an oil purifier.
[Explanation of symbols]
10 OF Cable 12 Inner Oil 14 Cell Oil Tank 16 Cell 18 Outer Oil 30a Inlet 30b Outlet 32a, 32b Main Valve 34 Oil Feeding Unit 36 Heating Unit 38 Oil Feeding Path 40a, 40b Emergency Shutoff Solenoid Valve 42 Flow Meter 44 Purification Unit 46 Bypass Valve 48 Bypass passage
