JP3618696B2 - Explosion-proof container cooling device - Google Patents

Description

【００１１】
耐圧防爆容器の外表面の温度上昇限度が表１のように定められているから、温度上昇を抑制するために耐圧防爆容器の内部を冷却する必要がある。従来の冷却方法のうち最も簡単なものは、別段の措置を講じることなく、耐圧防爆容器の表面から自然熱放散させるものである。容器の表面積を考慮してその熱放散による熱平衡温度を温度上昇限度以下に設計すればよい。しかし、自然熱放散は熱輻射や大気への熱伝導のメカニズムに依存し、電気装置群の発熱量が増大すると対応できない。耐圧防爆容器に放熱フィンを取り付ける場合もあるが、冷却能力とコストの点から不十分である。
【００１２】
冷却効率の高い方法は、耐圧防爆容器の外表面に水冷パイプを巻回して強制水冷する方法である。この方法は冷却効率が高いが、水冷パイプの容器への取付構造が複雑になり、また水流駆動用の電動ポンプを外部の爆発性雰囲気の中で運転しなければならないという問題がある。水冷方式に替えて耐圧防爆容器を強制空冷する場合でも同様の問題が発生する。
【００１３】
従がって、本発明に係る耐圧防爆容器の冷却装置は、耐圧防爆容器の内外の温度差だけを駆動源として用いることにより、耐圧防爆容器の内部を継続的に冷却でき、しかも爆発性雰囲気内において使用しても全く爆発を誘導しない冷却手段を提供する事を目的とする。また、このような冷却装置を開発する事により、発熱電気装置として例えばパソコンを例示すれば、このパソコンをガラス板を有した耐圧防爆容器内に配置して、爆発性雰囲気の中でパソコン操作を継続的に可能とする耐圧防爆容器を提供することを目的とする。
【００１４】
【課題を解決するための手段】
請求項１の発明は、中央に貫通孔２２ａを有する長さ寸法が２５ｍｍ以上の２の環状突起２２を上方部の壁面に突設した耐圧防爆容器２と、当該耐圧防爆容器２の内部空間の下方部に配設固定した電気装置４と、前記電気装置４の上方部に位置して耐圧防爆容器２の内部空間内に冷媒出口を冷媒入口よりも上方に位置せしめて配設固定され、冷媒液体の吸熱蒸発により耐熱防爆容器２の内部空間を冷却する蒸発器６と、挿入部２６と蓋部２８とから形成され、前記貫通孔２２ａ内へ０．２ｍｍ以下の間隙Ｇをもって挿入部２６が耐圧防爆容器２の内部から挿入されると共に蓋部２８の外周側の内面２３が環状突起２２の端面２３へ密着され、且つ中央部に挿入孔２４ａが形成された連結部材２４と、空調により耐圧防爆容器２の内部温度より低温度に保持された外部空間内に位置して耐圧防爆容器２の上方に配設され、放熱により冷媒ガスを凝縮させる凝縮器８と、前記一方の連結部材２４の挿入孔２４ａ内へ挿通せしめてこれに気密状に溶接されると共に耐圧防爆容器２の内部空間側の端部が前記蒸発器６の冷媒入口側へ、また耐圧防爆容器２の外方側の端部が凝縮器８の冷媒出口側へ夫々連結された冷媒導入管２０と、前記他方の連結部材２４の挿入管２４ａ内へ挿通せしめてこれに気密状に溶接されると共に、耐圧防爆容器２の内部空間側の端部が前記蒸発器６の冷媒出口側へ、また、耐圧防爆容器２の外方側の端部が凝縮器８の冷媒入口側へ夫々連結された冷媒導出管１２と、前記凝縮器８の上部に配設され、凝縮器８で熱交換をした外部爆発性雰囲気をその内部を通して上方へ排出することにより、外部爆発性雰囲気を循環させる凝縮塔８ｂとから構成したことを発明の基本構成とするものである。
【００１５】
請求項２の発明は、中央に貫通孔２２ａを有する長さ寸法が２５ｍｍ以上の２の環状突起２２を下方部の壁面に突設した耐圧防爆容器２と、当該耐圧防爆容器２の内部空間の中方部に配設固定した電気装置４と、前記電気装置４の下方部に位置して耐圧防爆容器２の内部空間内に冷媒出口を冷媒入口よりも上方に位置せしめて配設固定され、冷媒液体の吸熱蒸発により耐熱防爆容器２の内部空間を冷却する蒸発器６と、挿入部２６と蓋部２８とから形成され、前記貫通孔２２ａ内へ０．２ｍｍ以下の間隙Ｇをもって挿入部２６が耐圧防爆容器２の内部から挿入されると共に蓋部２８の外周側の内面２３が環状突起２２の端面２３へ密着され、且つ中央部に挿入孔２４ａが形成された連結部材２４と、空調により耐圧防爆容器２の内部温度より低温度に保持された外部空間内に位置して耐圧防爆容器２の上方に配設され、放熱により冷媒ガスを凝縮させる凝縮器８と、前記一方の連結部材２４の挿入孔２４ａ内へ挿通せしめてこれに気密状に溶接されると共に耐圧防爆容器２の内部空間側の端部が前記蒸発器６の冷媒入口側へ、また耐圧防爆容器２の外方側の端部が凝縮器８の冷媒出口側へ夫々連結された冷媒導入管２０と、前記他方の連結部材２４の挿入管２４ａ内へ挿通せしめてこれに気密状に溶接されると共に、耐圧防爆容器２の内部空間側の端部が前記蒸発器６の冷媒出口側へ、また、耐圧防爆容器２の外方側の端部が凝縮器８の冷媒入口側へ夫々連結された冷媒導出管１２と、前記耐圧防爆容器６の内部に設けた蒸発器６の下方に設けた内部ファン４０と、前記耐圧防爆容器６の内部に設けたモータにより駆動され、凝縮器８へ送風をする外部ファン４１とから構成したことを発明の基本構成とするものである。
【００２０】
【発明の実施の形態】
以下に、本発明に係る耐圧防爆容器の冷却装置の実施形態を図面に従がって詳細に説明する。
【００２１】
図１は、耐圧防爆容器の冷却装置の実施形態の概略断面図である。耐圧防爆容器２は爆発性雰囲気Ａの中に配置されているため、耐圧防爆容器２の内部も侵入した爆発性雰囲気Ｂによって充満されている。
【００２２】
耐圧防爆容器２の中には火花を発生する可能性のある電気装置４が配置されており、電気装置４が発した火花放電で内部爆発性雰囲気Ｂが爆発したとしても、爆発による火炎は耐圧防爆容器２により遮断されるために、外部爆発性雰囲気Ａの誘爆は阻止されている。
【００２３】
電気装置４は運転により絶えず熱エネルギーを発生するから、耐圧防爆容器２の内部には熱が溜まり、その結果、内部の温度は高温度Ｔ_Ｂに保持される。電気装置４の消費電力が大きくなったり、複数の電気装置４が集積されると、その高温度Ｔ_Ｂも当然上昇する。これに対し、外部爆発性雰囲気Ａは安全を期するために空調により低温度Ｔ_Ａに保持される。
【００２４】
このように、一般的にＴ_Ｂ＞Ｔ_Ａの関係は成立しているが、空調条件や電気装置の消費電力、また取り扱う爆発性気体の種類に応じて、Ｔ_Ａ・Ｔ_Ｂの具体的な値は多少変動する。
【００２５】
本発明の冷却装置は、高温度Ｔ_Ｂと低温度Ｔ_Ａの温度差を駆動力としている。即ち、耐圧防爆容器２の中には蒸発器６が配置され、この蒸発器６の中で高温度Ｔ_Ｂにより冷媒が液体から気体へと蒸発し、この吸熱蒸発を通して内部が冷却される。
【００２６】
耐圧防爆容器２の外部には凝縮器８が配置されており、外部低温度Ｔ_Ａにより冷媒が気体から液体へと凝縮され、この凝縮過程で熱は外部爆発性雰囲気Ａに放出され、この熱は空調作用により更に外部へと放出される。
【００２７】
蒸発器６には蒸発管１０が包含されており、この蒸発管１０は導出管１２及び導出バルブ１４を介して凝縮管１６に連続している。凝縮管１６は凝縮器８の中を通り、導入バルブ１８及び導入管２０を介して蒸発管１０に連続している。
【００２８】
図１には、蒸発器６の中における蒸発管１０の配管構造や、凝縮器８の中における凝縮管１６の配管構造は具体的に表していない。これらの配管構造は公知の構造から種々に選択できる。
【００２９】
導入管１２と耐圧防爆容器２の挿通構造は、環状突起２２と連結部材２４によって構成される。つまり、耐圧防爆容器２に貫通孔２２ａを有した環状突起２２を形成し、この貫通孔２２ａの中に挿通孔２４ａを有した連結部材２４を嵌着する。前記導出管１２はこの挿通孔２４ａの中に挿入されている。
【００３０】
導入管２０と耐圧防爆容器２の挿通構造は、前述した導入管１２と耐圧防爆容器２の挿通構造と同様である。蒸発管１０、導出管１２、導出バルブ１４、凝縮管１６、導入バルブ１８及び導入管２０は液密状に連続配管され、この配管内に冷媒Ｆが充填されている。
【００３１】
冷媒Ｆとしては公知のガスを使用できる。冷媒Ｆは、低温度Ｔ_Ａでは液体であり、高温度Ｔ_Ｂで気体になるガスであればよい。換言すれば、Ｔ_Ａ＜沸点＜Ｔ_Ｂの条件が成立すればよいが、沸点は封入圧力に依存する。従がって、低温度Ｔ_Ａと高温度Ｔ_Ｂが決った段階で、上記の沸点条件を満足するように、使用するガスの封入圧力が決められる。
【００３２】
一般的な作業現場では、低温度はＴ_Ａ＝１５℃〜３０℃、高温度はＴ_Ｂ＝３５℃〜５０℃であることが多い。ガスの安全性や１気圧での標準沸点の観点から、冷媒としてフロンや代替フロンが用いられることが多い。しかし、条件が合致する限り、フロン以外のガスも使用できる。
【００３３】
フロンとしては、ＣＦＣ−１１、ＣＦＣ−１２、ＣＦＣ−１３、ＣＦＣ−１１３、ＣＦＣ−１１４、ＣＦＣ−１１５、ＨＣＦＣ−２２、ＨＣＦＣ−１２３、ＨＣＦＣ−１２４、ＨＣＦＣ−２２５ａａ、ＨＣＦＣ−１４１ｂ、ＨＣＦＣ−１４２ｂ、ＨＣＦＣ−４０１、ＨＣＦＣ−４０８Ａ、ＨＣＦＣ−４０９Ａなどが利用される。しかし、オゾン層を破壊するものとして禁止されているフロンや将来禁止される虞のあるフロンは使用しない方が望ましい。
【００３４】
代替フロンとしては、ＨＦＣ−２３、ＨＦＣ−３２、ＨＦＣ−１２５、ＨＦＣ−１３４ａ、ＨＦＣ−１４３ａ、ＨＦＣ−１５２ａ、ＨＦＣ−２２７ｅａ、ＨＦＣ−２４５ｃａ、ＨＦＣ−４０４Ａ、ＨＦＣ−４０７Ａ、ＨＦＣ−４１０Ａ、ＨＦＣ−５０７Ａ、ＴＳ−０１２などが利用できる。
【００３５】
その他の冷媒、例えば、Ｈｅ、Ｈ_２、Ｎｅ、Ｎ_２、Ａｒ、Ｏ_２、ＣＦ_４、Ｎ_２Ｏ、ＣＦ_３ＣＦ_３、ＣＯ_２、ＣＦ_２ＣＦ_２、ＣＨ_３ＣＨＣＨ_２、ＣＨ_３ＣＨ_２ＣＨ_３、ＣＦ_３ＣＦ_２ＣＦ_３、ＮＨ_３、ＣＦ_３ＣＦ_２ＯＣＨ_３、ＣＨ（ＣＨ_３）_３、ＳＯ_２、Ｃ_４Ｆ_８、ＣＨ_３ＣＨ_２ＣＨ_２ＣＨ_３、ＣＦ_３ＣＦ_２ＯＣＨ_３、Ｈ_２Ｏ等も条件が合致する範囲において使用する事ができる。
【００３６】
蒸発器６では冷媒Ｆが蒸発して矢印ｂ方向に上昇し、導出管１２を矢印ｃ方向に移動する。更に、冷媒Ｆは凝縮器８を矢印ｄ方向に下降し、導入管２０を矢印ａ方向に移動して、以後循環を繰り返す。
【００３７】
外部低温度Ｔ_Ａと内部高温度Ｔ_Ｂの温度差が大きいほど、冷媒Ｆの循環率は大きくなる。つまり、蒸発器６で冷媒Ｆが蒸発する場合、液体中に微小気泡が生成して沸騰し、この微小気泡に作用する浮力の大きさにガスの循環速度が依存し、前記温度差が大きいほど循環速度が大きくなる。例えば、平均的にＴ_Ａ＝２５℃、Ｔ_Ｂ＝４５℃であれば十分に冷媒の循環が継続するが、温度条件がこれらの値に限定されない事は前述したとおりである。
【００３８】
図１では、蒸発器６と蒸発管１０を傾斜させた場合を示しているが、直立させてもよい。また、傾斜させる場合には傾斜角度も自在に設定する事ができる。蒸発管１０を傾斜させると冷媒の循環が効率的になる。蒸発器６は吸熱構造をとり、凝縮器８は放熱構造をとるように設計される。
【００３９】
図２は蒸発器と凝縮器を具体化した実施形態の概略断面図である。蒸発器６は傾斜蒸発管１０ａの周りに多数の吸熱用フィン１１を積層して形成されている。この吸熱用フィン１１により熱を吸収して、冷媒Ｆを強力に気化させて冷却作用を発揮させている。勿論、蒸発管１０を繰り返し蛇行させたジグザグ蒸発管に成形しても構わない。
【００４０】
凝縮器８の中では、放熱を効率化させるために、凝縮管１６はジグザグ状に配置されたジグザグ凝縮管１６ａとなっている。このジグザグ行路の中で、効率的な放熱が生起して気体が液体へと凝縮する。放熱効率を向上させるために、他の公知の構造を採用する事もできる。
【００４１】
図３は図１の部分拡大図であり、導入管１２及び導出管２０と耐圧防爆容器２との連結状態が示されている。連結部材２４は長さＬの挿入部２６と蓋部２８から構成され、蓋部２８の直径は環状突起２２の外径と同一に形成されている。つまり、蓋部２８は環状突起２２の上端面２３に当接され、接触面は上端接合部３２を形成して、連結部材２４を環状突起２２に圧入している。
【００４２】
内部爆発が生じた場合には、蓋部２８は内部の爆圧により上端面２３側に圧接され、上端接合部３２は密着によって隙間がなくなり、この上端接合部３２を通って火炎が外部に逸走することはない。
【００４３】
火炎の逸走を遮断するには、連結部材２４が貫通孔２２ａに隙間無く嵌着されることが望ましい。しかし、実際には寸法上のクリアランスがあるため、挿入部２６の外周には微小な環状の隙間Ｇが形成されることが多い。この隙間Ｇを通した火炎の逸走を遮断するためには、隙間Ｇは次のように法令が規定する寸法サイズに形成される必要がある。
【００４４】
隙間Ｇが隙間厚Ｄ及び隙間長さＬを有するとすると、隙間厚Ｄが０．２ｍｍ以下に、隙間長さＬが２５ｍｍ以上に設計されると、この隙間Ｇを通じて内部爆発の火炎が外部に逸走しないことが実験的に裏付けられており、この隙間のサイズは同時に法定されている。
【００４５】
もちろん、隙間厚Ｄがゼロに近いほど火炎遮断機能は高くなるが、実際には隙間厚Ｄをゼロにする加工は困難であり、隙間厚Ｄが０．２ｍｍ以下になるような精度で連結部材２０が研削加工され、火炎逸走の遮断が図られる。
【００４６】
上述したように、上端接合部３２は単に圧入しただけで溶接やネジ締め等の部材固定を行なっていない。部材固定しなくても火炎逸走が生じないためであり、また連結部材の圧入だけの方が組立てが簡単である。しかし、溶接やネジ締めなどの手段を排するわけではなく、必要に応じて付加的に施す事も可能である。
【００４７】
連結部材２４の挿通孔２４ａには導入管１２又は導出管２０が挿入され、蓋部２８と導入管１２又は導出管２０との円周状の接触部には管部溶接部３０が形成される。この管部溶接部３０により連結部材２４と導入管１２又は導出管２０とは一体化される。
【００４８】
管部溶接部３０が円周状に隙間を完全に遮蔽すると、この隙間を通じた火炎逸走は生じない。管部溶接部３０の円周距離は短いから、通常は管部溶接部３０により隙間を完全に遮断することが行なわれる。
【００４９】
管部溶接部３０に加えて、導入管１２又は導出管２０を挿通孔２４ａに密着状に挿通することが望ましい。密着しておれば火炎の逸走はないからである。密着が加工精度から困難である場合には、前述と同様の寸法精度を有した微小な隙間が導入管１２又は導出管２０と挿通孔２４ａとの接触面に形成される。つまり、この隙間は０．２ｍｍ以下の厚みと２５ｍｍ以上の長さを有するように設計されることにより、この隙間を通しての火炎逸走は遮断できる。
【００５０】
図４は本発明に係る耐圧防爆容器の冷却装置における冷媒動作の説明図である。この図では、蒸発管１０及び凝縮管１６の構造は簡略化して示されている。即ち、蒸発管１０、導出管１２、凝縮管１６及び導入管２０が連結されて四角状の配管状態で配置されている。
【００５１】
冷媒Ｆは配管の下部では冷媒液体Ｆ_Ｌとして存在し、配管の上部では冷媒ガスＦ_Ｇとして存在している。耐圧防爆容器２の中では、内部高温度Ｔ_Ｂにより冷媒液体Ｆ_Ｌは微細な気泡３４を発生しながら沸騰する。この沸騰過程で、耐圧防爆容器２の内部から熱を吸収し、内部を冷却する。また、この沸騰浮力により冷媒ガスＦ_Ｇは上昇力を得て矢印ｂ方向に移動する。
【００５２】
この冷媒ガスＦ_Ｇの上昇力は循環力となり、矢印ｃ方向に移動して冷媒ガスＦ_Ｇは外部低温度Ｔ_Ａと接触するようになる。更に、矢印ｄ方向に下降する中で、冷媒ガスＦ_Ｇは熱を放出して凝縮、即ち液化される。冷媒ガスＦ_Ｇは冷媒液体Ｆ_Ｌへと液化された後、この冷媒液体Ｆ_Ｌは矢印ａ方向へと移動する。
【００５３】
冷媒Ｆはこの循環を繰り返しながら、耐圧防爆容器２の内部を冷却し、外部に放出された熱量は容器外の空調作用により更に外部へと運ばれる。このようにして、本発明装置により耐圧防爆容器２の内部が内外の温度差だけを駆動力として冷却される。従って、この冷却装置は電気的動力を全く使用しないので火花が発生する事は無く、爆発性気体の雰囲気内で使用しても極めて安全である。
【００５４】
図５はパソコン用の耐圧防爆容器の冷却装置の概略構成図である。この装置は前述してきた冷却装置をパソコン用に具体的に適用したものである。耐圧防爆容器２の中には、電気装置４としてパソコン装置一式、即ちディスプレイ４ａ及びパソコン本体４ｂが配置されている。これらのパソコン装置は電気火花を発する危険性を有しているため耐圧防爆容器２の中に配置される。
【００５５】
他方、キーボード４ｃは外部爆発性雰囲気Ａの中に配置されている。キーボードは一般に火花を発する危険性がないと云われているので、この実施例ではキーボードに対する防爆化は考慮されていない。耐圧防爆容器２にはガラス窓が設けられており、耐圧防爆容器２の中のディスプレイ４ａを見ながらキーボード操作が行なわれる。
【００５６】
蒸発器６には上面に蒸発塔６ｂが形成されており、蒸発器６の全体は耐圧防爆容器２の上方に配置されている。パソコン装置の排熱により内部爆発性雰囲気Ｂは矢印ｅ方向へと上昇し、この高温雰囲気を多数の吸熱用フィン１１と接触させて、冷媒Ｆを吸熱蒸発させる。一方、高温雰囲気は熱交換後にやや低温化し、矢印ｆ方向へと降下し、耐圧防爆容器２の中で循環する。
【００５７】
外部爆発性雰囲気Ａの中にある凝縮器８は耐圧防爆容器２の上方に配置されており、その上面には煙突状の凝縮塔８ｂが立設されている。凝縮器８の下面には多数の放熱用フィン８ａが垂設されている。
【００５８】
外部爆発性雰囲気Ａは空調されているため低温度Ｔ_Ｂとなっている。一方、冷媒ガスＦ_Ｇは導出管１２を矢印ｃ方向に上昇して凝縮器８の中に進入する。外部爆発性雰囲気Ａは対流しながら凝縮器８へと矢印ｇ方向に上昇し、放熱用フィン８ａと接触し吸熱して高温化し、その過程で冷媒ガスＦ_Ｇは冷却されて冷媒液体Ｆ_Ｌへと凝縮される。
【００５９】
冷媒液体Ｆ_Ｌは導入管２０を矢印ａ方向へと下降して蒸発器６へと帰還する。他方、高温化した外部雰囲気は凝縮塔８ｂの中を高く上昇し、矢印ｉ方向に排出されて外部爆発性雰囲気Ａの大循環が生起する。凝縮塔８ｂから排出されると、下降する間に空調によって外部雰囲気は冷却され、再び矢印ｇ方向へと進入して対流の大循環を繰り返す。
【００６０】
凝縮塔８ｂを高く構成している理由は、外部爆発性雰囲気Ａを大循環させ、この緩慢な大循環過程の中で空調によって外部雰囲気を効果的に冷却させるためである。下降した段階では冷却されており、再び凝縮器８の中に進入して熱交換が効率的に行なわれる。
【００６１】
図５に示す耐圧防爆容器の冷却装置は無動力で作動し、耐圧防爆容器２の内部高温度Ｔ_Ｂと外部低温度Ｔ_Ａの温度差が冷却駆動力の原因となっている。このような装置構成とすれば、パソコン装置を耐圧防爆容器２の中に配置して、外部爆発性雰囲気Ａの中でパソコン作業を実現できる。
【００６２】
図６はコンプレッサーを用いたパソコン用耐圧防爆容器の冷却装置の概略斜視図である。この実施形態は、外部爆発性雰囲気Ａが空調されない場合を示し、外部温度Ｔ_Ａと内部温度Ｔ_Ｂにほとんど温度差がないか、逆にＴ_Ａ＞Ｔ_Ｂとなるような場合も含む。従って、図１〜図５がＴ_Ａ＜Ｔ_Ｂを前提としているのと対照的である。冷媒Ｆの圧縮と循環駆動をコンプレッサー４２を用いて行なうもので、耐圧防爆容器２の内部を強制冷却する方式である。
【００６３】
パソコン用デスク３８の上には耐圧防爆容器２とキーボード４ｃが載置されており、耐圧防爆容器２の中にパソコン装置としてディスプレイ４ａとパソコン本体４ｂが収納されている。ガラス板２ａを透視しながらキーボード４ｃを操作してパソコン作業を行なう。
【００６４】
耐圧防爆容器２の底部には、内部ファン４０と、その上に蒸発器６が配置されている。耐圧防爆容器２の背面にはワイヤ状の凝縮器８が配置され、パソコン用デスク３８の下段テーブルにはコンプレッサー４２が配置されている。このコンプレッサー４２は外部爆発性雰囲気Ａの中に露出されているため、防爆型のコンプレッサーが使用されている。このコンプレッサー４２を耐圧防爆容器２内に配置する場合には非防爆型のコンプレッサーで構わない。
【００６５】
コンプレッサー４２から蒸発器６には導入管２０が連結され、蒸発器６から凝縮器８には導出管１２が連結され、凝縮器８からコンプレッサー４２には圧縮管４４が連結されて冷媒循環路が構成されている。
【００６６】
内部ファン４０によって内部爆発性雰囲気Ｂが蒸発器６の中に矢印ｍ方向へと吸い込まれ、高温度Ｔ_Ｂの内部雰囲気によって冷媒液体Ｆ_Ｌは吸熱蒸発して冷媒ガスＦ_Ｇとなる。この過程で内部爆発性雰囲気Ｂは冷却され、再びパソコンの発熱で高温度Ｔ_Ｂとなり、内部循環を反復する。
【００６７】
蒸発した冷媒ガスＦ_Ｇは導出管１２を矢印ｃ方向に上昇して凝縮器８に進入する。凝縮器８の中で冷媒ガスＦ_Ｇは外部爆発性雰囲気Ａと接触して放熱しながら凝縮する。外部爆発性雰囲気Ａは空調されていないから、吸収した熱は自然循環によって外部雰囲気全体に拡散する。
【００６８】
凝縮器８で形成された冷媒Ｆは圧縮管４４を矢印ｋ方向へと降下し、コンプレッサー４２へと循環する。そしてコンプレッサー４２により圧縮されて完全に液化した後、導入管２０を介して矢印ａ方向へと供給され、蒸発器６へと帰還する。このコンプレッサー４２は導出管１２の途中に連結してもよく、またその場合でも耐圧防爆容器２の内部に配置されてもよい。内部配置では非防爆型のコンプレッサーでもよいが、外部配置する場合には安全のため防爆型コンプレッサーが用いられる。
【００６９】
このパソコン用の冷却装置は、コンプレッサー４２と内部ファン４０という動力装置を使用している点で図５の装置と異なっている。この実施例では耐圧防爆容器２の中にパソコン装置を収納しているが、任意の電気装置を収納できることは云うまでもない。
【００７０】
図７は外部ファンを用いた耐圧防爆容器の冷却装置の概略構成図である。この実施形態の特徴は、外部低温度ＴＡと内部高温度ＴＢの温度差が小さくなってきた場合に、凝縮器をファンで送風して凝縮効率を高めることである。耐圧防爆容器２の中には任意の電気装置４が配置されている。耐圧防爆容器２の下方には内部ファン４０と蒸発器６が配置され、内部ファン４０により高温度Ｔ_Ｂの内部爆発性雰囲気Ｂが矢印ｍ方向に蒸発器６の中に圧送されてゆく。
【００７１】
蒸発器６と熱交換した内部爆発性雰囲気Ｂは電気装置４で暖められ、矢印ｎ方向へと対流し、耐圧防爆容器２の中に対流循環が形成される。
【００７２】
耐圧防爆容器２の上面の左右には支持杆４６ａ、４６ａが立設され、その上端に支持台４６が設けられている。この支持台４６の上には凝縮器８が配置されている。この凝縮器８の下面に対向して外部ファン４１が設けられ、この外部ファン４１のモータ部は耐圧防爆容器２の中に収容されている。従って、電気火花を発生する可能性のある部材は全て耐圧防爆容器２の中に収容している。
【００７３】
蒸発器６で形成された冷媒ガスＦ_Ｇは導出管１２を通って矢印ｃ方向に上昇し、凝縮器８に進入する。外部爆発性雰囲気Ａは空調により低温度Ｔ_Ａに冷却されているが、空調力が弱い場合には凝縮効率が悪くなるから、外部ファン４１により外部爆発性雰囲気Ａを矢印ｇ方向に凝縮器８へと吹き込んで、凝縮効率を高める作用をする。
【００７４】
冷媒ガスＦ_Ｇは凝縮器８の中で熱を失って冷媒液体Ｆ_Ｌへと変化する。この冷媒液体Ｆ_Ｌは導入管２０の中を矢印ａ方向に流下し、蒸発器６に帰還する。また、熱を吸収して高温化した外部爆発性雰囲気Ａは空調によって冷却される。再び、このサイクルを繰り返しながら、耐圧防爆容器２の中は継続的に冷却され続けることになる。
【００７５】
この図７の冷却装置も、内部ファン４０とともに外部ファン４１という動力装置を利用して、温度差に基づく冷媒循環を継続させるもので、半動力方式といってもよい。このように、本発明では完全無動力方式から半動力方式までを含みながら、爆発性雰囲気の中で動作する電気装置の冷却装置を実現したものである。
【００７６】
本発明は上記実施形態に限定されるものではなく、本発明の技術的思想を逸脱しない範囲における種々の変形例や設計変更などをその技術的範囲内に包含することは云うまでもない。
【００７７】
【発明の効果】
請求項１の発明によれば、耐圧防爆容器の内外の温度差だけで冷媒を循環駆動して耐圧防爆容器の内部を冷却するから、冷却装置として電気装置が全く不要になり、爆発性雰囲気において使用しても極めて安全な冷却装置を提供できる。しかも蒸発器と凝縮器を耐圧防爆容器の内外に配置して配管するだけであるから、任意の構造の耐圧防爆容器に対しても配設が可能で、冷却効果を確実に発揮する事ができる。
【００７８】
請求項２の発明によれば、蒸発器と凝縮器を接続する配管は耐圧防爆容器の内部において爆発が生じても破断しない耐爆強度を有しているから、配管系を通して火炎が外部に逸走する危険性は無い。しかも、配管と耐圧防爆容器との結合部においても火炎逸走が生じない隙間設計がなされているから、耐圧防爆容器内において爆発が生じても、外部まで誘爆する危険性は無く、構造上の安全性が保障されている。
【００７９】
請求項３の発明によれば、前記凝縮器の上に煙突状の凝縮塔を立設し、凝縮器で熱交換した外部爆発性雰囲気を凝縮塔の上から排出させて外部爆発性雰囲気を大循環させているから、熱交換で温度上昇した外部爆発性雰囲気を大循環の中で空調により急速に冷却させることができ、外部爆発性雰囲気の低温度を保持して冷却装置の継続性と安定性を確保する。
【００８０】
請求項４の発明によれば、耐圧防爆容器の中に内部ファンを配置するから、内部爆発性雰囲気を循環させることにより、内部爆発性雰囲気と蒸発器との熱交換を円滑化し、配置された電気装置の排熱を蒸発器により冷媒へと強制移動することができる。
【００８１】
請求項５の発明によれば、外部と内部の温度差が小さくなった場合に、凝縮器の近傍にファンを配置して外部爆発性雰囲気を強制循環させ、外部爆発性雰囲気と凝縮器との熱交換を強化することにより、電気装置の冷却効率を向上させることができる。
【００８２】
請求項６の発明によれば、外部雰囲気が空調されないで外部温度が高温化した場合に、蒸発器と凝縮器の間にコンプレッサーを接続し、蒸発器と凝縮器の間の冷媒循環と冷媒の圧縮を強制的に行なわせることができ、発熱する電気装置を内蔵した耐圧防爆容器内を強制的に冷却することができる。
【図面の簡単な説明】
【図１】耐圧防爆容器の冷却装置の実施形態の概略断面図である。
【図２】蒸発器と凝縮器を具体化した実施形態の概略断面図である。
【図３】図１の部分拡大図である。
【図４】耐圧防爆容器の冷却装置における冷媒動作の説明図である。
【図５】パソコン用の耐圧防爆容器の冷却装置の概略構成図である。
【図６】コンプレッサーを用いたパソコン用の耐圧防爆容器の冷却装置の概略斜視図である。
【図７】ファンを用いた耐圧防爆容器の冷却装置の概略構成図である。
【符号の説明】
２は耐圧防爆容器、４は電気装置、４ａはディスプレイ、４ｂはパソコン本体、４ｃはキーボード、６は蒸発器、６ｂは蒸発塔、８は凝縮器、８ａは放熱用フィン、１０は蒸発管、１０ａは傾斜蒸発管、１１は吸熱用フィン、１２は導出管、１４は導出バルブ、１６は凝縮管、１６ａはジグザグ凝縮管、１８は導入バルブ、２０は導入管、２２は環状突起、２２ａは貫通孔、２３は上端面、２４は連結部材、２４ａは挿通孔、２６は挿入部、２８は蓋部、３０は管部溶接部、３２は上端接合部、３４は気泡、３８はパソコン用デスク、４０は内部ファン、４１は外部ファン、４２はコンプレッサー、４４は圧縮管、４６は支持台、４６ａは支持杆、Ａは外部爆発性雰囲気、Ｂは内部爆発性雰囲気、Ｄは隙間厚、Ｇは隙間、Ｆは冷媒、Ｆ_Ｇは冷媒ガス、Ｆ_Ｌは冷媒液体、Ｌは隙間長さ、Ｔ_Ａは外部低温度、Ｔ_Ｂは内部高温度。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pressure-proof explosion-proof container in which an electric device having a possibility of spark discharge is arranged inside, and the flame does not escape outside the container even if it is applied to the internal explosive atmosphere and explodes. Inside the explosion-proof container, the internal atmosphere becomes hot due to the heat generated by the electrical equipment, while the external space is kept at a relatively low temperature by air conditioning or the like, and this temperature difference is used to circulate the refrigerant between the internal space and the external space. In addition, the present invention relates to a cooling device for a flameproof container that absorbs heat of the internal space and releases it to the external space to cool the internal space.
[0002]
[Prior art]
In general, establishments that use flammable gases or flammable liquids must be careful when handling equipment because the atmosphere is explosive. Especially for electrical devices used in explosive atmospheres, there is a possibility that sparks may be generated while the electrical devices are in operation. There is a danger of causing great damage and damage.
[0003]
Therefore, it is obliged to take explosion-proof measures for electrical devices used in explosive atmospheres. For example, the Industrial Safety and Health Law stipulates that unless an explosion-proof certification is obtained, it must not be transferred, rented, or installed as an explosion-proof device.
[0004]
Occupational safety and health regulations also stipulate that when electrical equipment is used in locations where there is a risk of reaching explosive concentrations, it must be used only for explosion-proof electrical equipment that has explosion-proof performance. . For example, even when a personal computer is used in an explosive atmosphere, it is necessary to make the personal computer explosion-proof.
[0005]
The explosion-proof structure of each electrical device is stipulated in the factory electrical equipment explosion-proof guidelines, and it is required to design the overall and detailed structure of the electrical devices to satisfy the provisions of this guideline.
[0006]
For example, when explaining the explosion-proof structure of an electric motor, the parts that generate electric sparks even during normal operation, such as slip rings, commutators, and starting contacts must be explosion-proof, and the allowable restraint time is set to 5 seconds or more. The structure and function are finely defined such that the size of the air gap between the rotor and the rotor is designed to be a predetermined value or less. However, if an explosion-proof electric motor that satisfies these conditions is made, the cost is several to several tens of times that of a normal electric motor. The increase in price due to such explosion-proofing is the same in other electric devices.
[0007]
Therefore, instead of explosion-proofing the individual electric devices, the inventor integrates an electric device or a group of electric devices having a risk of generating an electric spark in one explosion-proof container, and within the explosion-proof container. Even if the explosive gas inside the container explodes due to the generated spark, a refrigerator-freezer having a structure in which the flame does not leak to the outside (runaway) has been completed, and this invention has been disclosed as Japanese Patent No. 2994350.
[0008]
[Problems to be solved by the invention]
Certainly, if the electric device group is integrated in a sturdy explosion-proof container, there is an advantage that the individual electric devices need not be explosion-proof. However, since the electric device is also an electric heating element, if the electric device or the electric device group is sealed in the explosion-proof container, the internal temperature of the explosion-proof container increases rapidly. This high temperature has a risk of heating the explosion-proof container and igniting and exploding an external explosive atmosphere in contact with the container.
[0009]
Therefore, according to the ignition temperature of the explosive gas, the temperature rise limit of the outer surface of the pressure-proof explosion-proof container is set in the factory electrical equipment explosion-proof guidelines. The degree of ignition of explosive gas to be handled is classified into six stages G1 to G6, and the temperature rise limit is determined as shown in Table 1 for each ignition degree.
[0010]

[0011]
Since the temperature rise limit of the outer surface of the explosion-proof container is determined as shown in Table 1, it is necessary to cool the inside of the explosion-proof container in order to suppress the temperature rise. The simplest of the conventional cooling methods is to dissipate natural heat from the surface of the explosion-proof container without taking any other measures. Considering the surface area of the container, the thermal equilibrium temperature due to the heat dissipation may be designed to be below the temperature rise limit. However, natural heat dissipation depends on the mechanism of heat radiation and heat conduction to the atmosphere, and cannot cope with an increase in the amount of heat generated by the electrical device group. Although heat radiation fins may be attached to the explosion-proof container, it is insufficient from the viewpoint of cooling capacity and cost.
[0012]
A method with high cooling efficiency is a method in which a water cooling pipe is wound around the outer surface of the explosion proof container and forced water cooling is performed. Although this method has high cooling efficiency, there is a problem in that the structure for mounting the water cooling pipe to the container is complicated, and the electric pump for driving the water flow must be operated in an external explosive atmosphere. The same problem occurs even when the explosion-proof container is forcibly air-cooled instead of the water cooling method.
[0013]
Accordingly, the cooling device for the explosion-proof container according to the present invention can continuously cool the inside of the explosion-proof container by using only the temperature difference between the inside and outside of the explosion-proof container as a driving source, and has an explosive atmosphere. It is an object of the present invention to provide a cooling means that does not induce an explosion at all even when used inside. In addition, by developing such a cooling device, for example, a personal computer as a heat generating electrical device, this personal computer is placed in an explosion-proof container having a glass plate so that the personal computer can be operated in an explosive atmosphere. The object is to provide an explosion-proof container that can be made continuously.
[0014]
[Means for Solving the Problems]
The invention of claim 1Two annular protrusions 22 having a through hole 22a in the center and having a length of 25 mm or more are disposed on and fixed to the lower part of the inner space of the explosion-proof container 2 and the explosion-proof container 2 projecting from the upper wall surface. The electric device 4 is positioned above the electric device 4 and fixed in the interior space of the explosion-proof container 2 with the refrigerant outlet positioned above the refrigerant inlet, and is heat-resistant and explosion-proof by endothermic evaporation of the refrigerant liquid. The evaporator 6 that cools the internal space of the container 2, the insertion part 26, and the lid part 28 are formed. The insertion part 26 is inserted into the through-hole 22 a from the inside of the explosion-proof container 2 with a gap G of 0.2 mm or less. The inner surface 23 on the outer peripheral side of the lid portion 28 is brought into close contact with the end surface 23 of the annular protrusion 22 and the insertion member 24 is formed at the center portion, and the internal temperature of the explosion-proof container 2 by air conditioning. Kept at low temperature It is located in the partial space and is disposed above the explosion-proof container 2, and is inserted into the condenser 8 for condensing the refrigerant gas by heat radiation and the insertion hole 24a of the one connecting member 24 so as to be airtight. While being welded, the end on the inner space side of the explosion-proof container 2 is connected to the refrigerant inlet side of the evaporator 6, and the outer end of the explosion-proof container 2 is connected to the refrigerant outlet side of the condenser 8. The refrigerant introduction pipe 20 and the insertion pipe 24a of the other connecting member 24 are inserted into the insertion pipe 24a and are airtightly welded thereto, and the end portion on the inner space side of the pressure-proof explosion-proof container 2 is the refrigerant of the evaporator 6. The refrigerant outlet pipe 12 is connected to the outlet side, and the outer end of the explosion-proof container 2 is connected to the refrigerant inlet side of the condenser 8, and the condenser 8 is provided above the condenser 8. Exhaust explosive atmosphere that has been heat-exchanged at More, in which the basic configuration of the invention that was formed from the condensation column 8b for circulating external explosive atmosphere.
[0015]
The invention of claim 2Two annular protrusions 22 having a through hole 22a in the center and having a length of 25 mm or more are disposed on and fixed to the middle part of the interior space of the explosion-proof container 2 and the explosion-proof container 2 projecting from the lower wall surface. The electric device 4 is positioned below the electric device 4 and fixed in the interior space of the explosion-proof explosion-proof container 2 with the refrigerant outlet positioned above the refrigerant inlet. The evaporator 6 that cools the internal space of the container 2, the insertion part 26, and the lid part 28 are formed. The insertion part 26 is inserted into the through-hole 22 a from the inside of the explosion-proof container 2 with a gap G of 0.2 mm or less. The inner surface 23 on the outer peripheral side of the lid portion 28 is brought into close contact with the end surface 23 of the annular protrusion 22 and the insertion member 24 is formed at the center portion, and the internal temperature of the explosion-proof container 2 by air conditioning. Kept at low temperature It is located in the partial space and is disposed above the explosion-proof container 2, and is inserted into the condenser 8 for condensing the refrigerant gas by heat radiation and the insertion hole 24a of the one connecting member 24 so as to be airtight. While being welded, the end on the inner space side of the explosion-proof container 2 is connected to the refrigerant inlet side of the evaporator 6, and the outer end of the explosion-proof container 2 is connected to the refrigerant outlet side of the condenser 8. The refrigerant introduction pipe 20 and the insertion pipe 24a of the other connecting member 24 are inserted into the insertion pipe 24a and are airtightly welded thereto, and the end portion on the inner space side of the pressure-proof explosion-proof container 2 is the refrigerant of the evaporator 6. A refrigerant outlet tube 12 in which the outer end of the explosion-proof container 2 is connected to the refrigerant inlet side of the condenser 8, and the evaporator 6 provided inside the explosion-proof container 6, respectively. An internal fan 40 provided at the bottom and provided inside the explosion-proof container 6 Driven by chromatography motor, in which the basic configuration of the invention that was constructed from external fan 41. for the blower to the condenser 8.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a cooling device for a flameproof container according to the present invention will be described below in detail with reference to the drawings.
[0021]
FIG. 1 is a schematic cross-sectional view of an embodiment of a cooling device for a flameproof container. Since the explosion-proof container 2 is disposed in the explosive atmosphere A, the inside of the explosion-proof container 2 is also filled with the explosive atmosphere B that has entered.
[0022]
An electric device 4 that can generate a spark is arranged in the explosion-proof container 2, and even if the internal explosive atmosphere B is exploded by a spark discharge generated by the electric device 4, the flame due to the explosion is pressure-resistant. Since it is blocked by the explosion-proof container 2, the explosion of the external explosive atmosphere A is prevented.
[0023]
Since the electric device 4 constantly generates thermal energy during operation, heat is accumulated in the explosion-proof container 2, and as a result, the internal temperature is high._BRetained. When the power consumption of the electric device 4 increases or when a plurality of electric devices 4 are integrated, the high temperature T_BOf course also rises. On the other hand, the external explosive atmosphere A has a low temperature T due to air conditioning to ensure safety._ARetained.
[0024]
Thus, in general, T_B> T_AHowever, depending on the air conditioning conditions, the power consumption of the electrical equipment, and the type of explosive gas to be handled, T_A・ T_BThe specific value of fluctuates somewhat.
[0025]
The cooling device of the present invention has a high temperature T_BAnd low temperature T_AIs the driving force. That is, an evaporator 6 is disposed in the explosion-proof container 2, and the high temperature T_BAs a result, the refrigerant evaporates from liquid to gas, and the inside is cooled through this endothermic evaporation.
[0026]
A condenser 8 is arranged outside the explosion-proof container 2, and an external low temperature T_AAs a result, the refrigerant is condensed from gas to liquid, and in this condensation process, heat is released to the external explosive atmosphere A, and this heat is further released to the outside by air conditioning.
[0027]
The evaporator 6 includes an evaporation pipe 10, and the evaporation pipe 10 is connected to a condensation pipe 16 via a lead-out pipe 12 and a lead-out valve 14. The condenser pipe 16 passes through the condenser 8 and continues to the evaporator pipe 10 via the inlet valve 18 and the inlet pipe 20.
[0028]
In FIG. 1, the piping structure of the evaporation pipe 10 in the evaporator 6 and the piping structure of the condensation pipe 16 in the condenser 8 are not specifically shown. These piping structures can be variously selected from known structures.
[0029]
The insertion structure of the introduction pipe 12 and the explosion-proof container 2 is constituted by an annular protrusion 22 and a connecting member 24. That is, the annular protrusion 22 having the through hole 22a is formed in the explosion-proof container 2, and the connecting member 24 having the insertion hole 24a is fitted into the through hole 22a. The outlet tube 12 is inserted into the insertion hole 24a.
[0030]
The insertion structure of the introduction tube 20 and the explosion-proof container 2 is the same as the insertion structure of the introduction tube 12 and the explosion-proof container 2 described above. The evaporation pipe 10, the outlet pipe 12, the outlet valve 14, the condenser pipe 16, the introduction valve 18, and the introduction pipe 20 are continuously liquid-tightly piped, and the refrigerant F is filled in the pipe.
[0031]
As the refrigerant F, a known gas can be used. Refrigerant F has a low temperature T_AIs liquid and has a high temperature T_BAny gas can be used as long as it becomes a gas. In other words, T_A<Boiling point <T_BHowever, the boiling point depends on the sealing pressure. Therefore, low temperature T_AAnd high temperature T_BIs determined, the sealing pressure of the gas to be used is determined so as to satisfy the above boiling point condition.
[0032]
In typical work sites, low temperatures are T_A= 15-30 ° C, high temperature is T_BIt is often 35 ° C. to 50 ° C. From the viewpoint of gas safety and standard boiling point at 1 atm, Freon and alternative Freon are often used as refrigerants. However, gases other than chlorofluorocarbons can be used as long as the conditions are met.
[0033]
CFC-11, CFC-12, CFC-13, CFC-113, CFC-114, CFC-115, HCFC-22, HCFC-123, HCFC-124, HCFC-225aa, HCFC-141b, HCFC- 142b, HCFC-401, HCFC-408A, HCFC-409A, etc. are used. However, it is desirable not to use chlorofluorocarbons that are prohibited to destroy the ozone layer or chlorofluorocarbons that may be prohibited in the future.
[0034]
Alternative CFCs include HFC-23, HFC-32, HFC-125, HFC-134a, HFC-143a, HFC-152a, HFC-227ea, HFC-245ca, HFC-404A, HFC-407A, HFC-410A, HFC -507A, TS-012, etc. can be used.
[0035]
Other refrigerants such as He, H₂, Ne, N₂, Ar, O₂, CF₄, N₂O, CF₃CF₃, CO₂, CF₂CF₂, CH₃CHCH₂, CH₃CH₂CH₃, CF₃CF₂CF₃, NH₃, CF₃CF₂OCH₃, CH (CH₃)₃, SO₂, C₄F₈, CH₃CH₂CH₂CH₃, CF₃CF₂OCH₃, H₂O or the like can be used within a range where the conditions are met.
[0036]
In the evaporator 6, the refrigerant F evaporates and rises in the direction of arrow b, and moves the outlet pipe 12 in the direction of arrow c. Further, the refrigerant F moves down the condenser 8 in the direction of arrow d, moves the introduction pipe 20 in the direction of arrow a, and thereafter repeats circulation.
[0037]
External low temperature T_AAnd internal high temperature T_BThe greater the temperature difference, the greater the circulation rate of the refrigerant F. That is, when the refrigerant F evaporates in the evaporator 6, microbubbles are generated and boiled in the liquid, the gas circulation speed depends on the buoyancy acting on the microbubbles, and the larger the temperature difference, the larger the temperature difference. Increases circulation speed. For example, on average T_A= 25 ° C, T_BAs long as = 45 ° C., the refrigerant continues to circulate sufficiently, but as described above, the temperature condition is not limited to these values.
[0038]
Although FIG. 1 shows the case where the evaporator 6 and the evaporator tube 10 are inclined, they may be made upright. In the case of tilting, the tilt angle can be freely set. When the evaporation pipe 10 is inclined, the circulation of the refrigerant becomes efficient. The evaporator 6 is designed to have an endothermic structure, and the condenser 8 is designed to have a heat dissipating structure.
[0039]
FIG. 2 is a schematic cross-sectional view of an embodiment embodying an evaporator and a condenser. The evaporator 6 is formed by laminating a number of endothermic fins 11 around the inclined evaporator tube 10a. Heat is absorbed by the endothermic fins 11, and the refrigerant F is strongly vaporized to exert a cooling action. Of course, the evaporator tube 10 may be formed into a zigzag evaporator tube meandering repeatedly.
[0040]
In the condenser 8, the condenser tube 16 is a zigzag condensing tube 16 a arranged in a zigzag shape in order to improve heat dissipation efficiency. In this zigzag route, efficient heat dissipation occurs and the gas condenses into a liquid. In order to improve the heat dissipation efficiency, other known structures can be employed.
[0041]
FIG. 3 is a partially enlarged view of FIG. 1, and shows a connection state between the introduction pipe 12 and the lead-out pipe 20 and the explosion-proof container 2. The connecting member 24 includes an insertion portion 26 having a length L and a lid portion 28, and the diameter of the lid portion 28 is the same as the outer diameter of the annular protrusion 22. That is, the lid portion 28 is in contact with the upper end surface 23 of the annular protrusion 22, and the contact surface forms the upper end joint portion 32, so that the connecting member 24 is press-fitted into the annular protrusion 22.
[0042]
When an internal explosion occurs, the lid portion 28 is pressed against the upper end surface 23 side by the internal explosion pressure, and the upper end joint portion 32 disappears due to close contact, and the flame escapes to the outside through the upper end joint portion 32. Never do.
[0043]
In order to block the escape of the flame, it is desirable that the connecting member 24 is fitted in the through hole 22a without any gap. However, since there is actually a dimensional clearance, a small annular gap G is often formed on the outer periphery of the insertion portion 26. In order to block the escape of the flame through the gap G, the gap G needs to be formed in a size size stipulated by laws and regulations as follows.
[0044]
Assuming that the gap G has a gap thickness D and a gap length L, when the gap thickness D is designed to be 0.2 mm or less and the gap length L is set to 25 mm or more, the flame of the internal explosion is exposed to the outside through the gap G. It has been experimentally confirmed that it does not run away, and the size of this gap is simultaneously legal.
[0045]
Of course, the closer the gap thickness D is to zero, the higher the flame blocking function is. However, in reality, it is difficult to make the gap thickness D zero, and the connecting member is accurate so that the gap thickness D is 0.2 mm or less. 20 is ground and the flame escape is cut off.
[0046]
As described above, the upper end joint portion 32 is simply press-fitted and does not fix a member such as welding or screw tightening. This is because flame escape does not occur even if the member is not fixed, and the assembly is simpler only by press-fitting the connecting member. However, means such as welding and screw tightening are not eliminated, and they can be additionally provided as necessary.
[0047]
The introduction pipe 12 or the lead-out pipe 20 is inserted into the insertion hole 24 a of the connecting member 24, and a pipe welded part 30 is formed at the circumferential contact portion between the lid portion 28 and the lead-in pipe 12 or the lead-out pipe 20. . The connecting member 24 and the introduction pipe 12 or the lead-out pipe 20 are integrated by the pipe welded portion 30.
[0048]
When the pipe welded part 30 completely shields the gap circumferentially, no flame escape occurs through the gap. Since the circumferential distance of the pipe welded portion 30 is short, the gap is usually completely blocked by the pipe welded portion 30.
[0049]
In addition to the pipe welded part 30, it is desirable to insert the introduction pipe 12 or the lead-out pipe 20 in close contact with the insertion hole 24a. This is because there is no flame escape if they are in close contact. When close contact is difficult due to processing accuracy, a minute gap having the same dimensional accuracy as described above is formed on the contact surface between the introduction tube 12 or the lead-out tube 20 and the insertion hole 24a. That is, the gap is designed to have a thickness of 0.2 mm or less and a length of 25 mm or more, so that flame escape through the gap can be blocked.
[0050]
FIG. 4 is an explanatory view of the refrigerant operation in the cooling device for the explosion-proof container according to the present invention. In this figure, the structures of the evaporation pipe 10 and the condensation pipe 16 are shown in a simplified manner. That is, the evaporation pipe 10, the outlet pipe 12, the condenser pipe 16 and the introduction pipe 20 are connected and arranged in a square pipe state.
[0051]
The refrigerant F is a refrigerant liquid F at the lower part of the pipe._LAs the refrigerant gas F at the top of the pipe_GExist as. Inside the explosion-proof container 2, the internal high temperature T_BRefrigerant liquid F_LBoils while generating fine bubbles 34. In this boiling process, heat is absorbed from the inside of the explosion-proof container 2 and the inside is cooled. In addition, this boiling buoyancy causes the refrigerant gas F_GMoves in the direction of the arrow b with an ascending force.
[0052]
This refrigerant gas F_GThe ascending force becomes a circulatory force and moves in the direction of arrow c to move the refrigerant gas F_GIs the external low temperature T_ACome into contact with. Furthermore, while descending in the direction of the arrow d, the refrigerant gas F_GReleases heat and condenses or liquefies. Refrigerant gas F_GIs refrigerant liquid F_LAfter being liquefied, the refrigerant liquid F_LMoves in the direction of arrow a.
[0053]
The refrigerant F cools the inside of the explosion-proof explosion-proof container 2 while repeating this circulation, and the amount of heat released to the outside is further carried to the outside by an air conditioning action outside the container. In this way, the apparatus of the present invention cools the inside of the explosion-proof container 2 using only the temperature difference between the inside and outside as a driving force. Therefore, since this cooling device does not use any electric power, no spark is generated, and it is extremely safe to use in an atmosphere of explosive gas.
[0054]
FIG. 5 is a schematic configuration diagram of a cooling device for a flameproof container for a personal computer. This apparatus is a specific application of the above-described cooling apparatus for a personal computer. In the explosion-proof container 2, a set of personal computer devices, that is, a display 4a and a personal computer main body 4b are arranged as the electric device 4. Since these personal computer devices have a risk of generating electric sparks, they are disposed in the explosion-proof container 2.
[0055]
On the other hand, the keyboard 4c is disposed in the external explosive atmosphere A. Since it is generally said that the keyboard has no risk of sparks, this embodiment does not consider explosion protection for the keyboard. The explosion-proof container 2 is provided with a glass window, and a keyboard operation is performed while viewing the display 4 a in the explosion-proof container 2.
[0056]
An evaporator 6 b is formed on the upper surface of the evaporator 6, and the entire evaporator 6 is disposed above the explosion-proof container 2. The internal explosive atmosphere B rises in the direction of arrow e due to the exhaust heat of the personal computer device, and this high temperature atmosphere is brought into contact with a large number of heat absorbing fins 11 so that the refrigerant F is absorbed and evaporated. On the other hand, the high-temperature atmosphere is slightly lowered after heat exchange, falls in the direction of arrow f, and circulates in the explosion-proof container 2.
[0057]
The condenser 8 in the external explosive atmosphere A is disposed above the explosion-proof container 2, and a chimney-shaped condensing tower 8b is erected on the upper surface thereof. A large number of heat radiation fins 8 a are suspended from the lower surface of the condenser 8.
[0058]
External explosive atmosphere A is air-conditioned and has a low temperature T_BIt has become. On the other hand, refrigerant gas F_GMoves up the outlet tube 12 in the direction of arrow c and enters the condenser 8. The external explosive atmosphere A rises in the direction of the arrow g to the condenser 8 while convection, contacts the heat radiation fin 8a and absorbs heat to increase the temperature, and in the process, the refrigerant gas F_GIs cooled and the refrigerant liquid F_LIt is condensed into.
[0059]
Refrigerant liquid F_LLowers the introduction pipe 20 in the direction of arrow a and returns to the evaporator 6. On the other hand, the high-temperature external atmosphere rises high in the condensation tower 8b and is discharged in the direction of arrow i, causing a general circulation of the external explosive atmosphere A. When discharged from the condensing tower 8b, the external atmosphere is cooled by air conditioning while descending, enters again in the direction of arrow g, and repeats the general circulation of convection.
[0060]
The reason why the condensing tower 8b is configured to be high is to circulate the external explosive atmosphere A in a large circulation and to effectively cool the external atmosphere by air conditioning in this slow general circulation process. In the lowered stage, it is cooled and enters the condenser 8 again, so that heat exchange is performed efficiently.
[0061]
The cooling device for the explosion-proof container shown in FIG. 5 operates without power, and the internal high temperature T of the explosion-proof container 2._BAnd external low temperature T_AThis temperature difference causes the cooling driving force. If it is such an apparatus structure, a personal computer apparatus can be arrange | positioned in the explosion-proof container 2, and a personal computer work can be implement | achieved in the external explosive atmosphere A. FIG.
[0062]
FIG. 6 is a schematic perspective view of a cooling device for a PC explosion-proof container using a compressor. This embodiment shows the case where the external explosive atmosphere A is not air-conditioned, and the external temperature T_AAnd internal temperature T_BThere is almost no temperature difference between_A> T_BThis includes cases where Accordingly, FIGS._A<T_BThis is in contrast to the premise that The refrigerant F is compressed and circulated using the compressor 42, and the inside of the pressure-proof explosion-proof container 2 is forcibly cooled.
[0063]
An explosion-proof container 2 and a keyboard 4c are placed on the personal computer desk 38. A display 4a and a personal computer main body 4b are housed in the explosion-proof container 2 as a personal computer device. The personal computer is operated by operating the keyboard 4c while seeing through the glass plate 2a.
[0064]
An internal fan 40 and an evaporator 6 are disposed on the bottom of the explosion-proof container 2. A wire-shaped condenser 8 is disposed on the back surface of the explosion-proof container 2, and a compressor 42 is disposed on the lower table of the personal computer desk 38. Since the compressor 42 is exposed in the external explosive atmosphere A, an explosion-proof compressor is used. When the compressor 42 is arranged in the explosion-proof container 2, a non-explosion-proof compressor may be used.
[0065]
The introduction pipe 20 is connected from the compressor 42 to the evaporator 6, the outlet pipe 12 is connected from the evaporator 6 to the condenser 8, and the compression pipe 44 is connected from the condenser 8 to the compressor 42, so that the refrigerant circulation path is formed. It is configured.
[0066]
The internal fan 40 sucks the internal explosive atmosphere B into the evaporator 6 in the direction of the arrow m, and the high temperature T_BDepending on the internal atmosphere of the refrigerant liquid F_LEndothermic evaporation refrigerant gas F_GIt becomes. In this process, the internal explosive atmosphere B is cooled, and the high temperature T is generated again by the heat generated by the personal computer._BAnd the internal circulation is repeated.
[0067]
Evaporated refrigerant gas F_GMoves up the outlet tube 12 in the direction of arrow c and enters the condenser 8. Refrigerant gas F in the condenser 8_GCondenses in contact with the external explosive atmosphere A while releasing heat. Since the external explosive atmosphere A is not air-conditioned, the absorbed heat is diffused throughout the external atmosphere by natural circulation.
[0068]
The refrigerant F formed in the condenser 8 descends in the direction of the arrow k in the compression pipe 44 and circulates to the compressor 42. Then, after being compressed by the compressor 42 and completely liquefied, it is supplied in the direction of arrow a through the introduction pipe 20 and returned to the evaporator 6. This compressor 42 may be connected in the middle of the outlet pipe 12, and even in that case, it may be arranged inside the explosion-proof container 2. The internal arrangement may be a non-explosion-proof type compressor, but an external explosion-proof type compressor is used for safety.
[0069]
This personal computer cooling apparatus is different from the apparatus shown in FIG. 5 in that a power device such as a compressor 42 and an internal fan 40 is used. In this embodiment, the personal computer device is accommodated in the explosion-proof container 2, but it goes without saying that any electrical device can be accommodated.
[0070]
FIG. 7 is a schematic configuration diagram of a cooling device for a flameproof container using an external fan. The feature of this embodiment is that when the temperature difference between the external low temperature TA and the internal high temperature TB becomes small, the condenser is blown by a fan to increase the condensation efficiency. An optional electric device 4 is arranged in the explosion-proof container 2. An internal fan 40 and an evaporator 6 are arranged below the explosion-proof container 2, and the internal fan 40 causes a high temperature T._BThe internal explosive atmosphere B is pumped into the evaporator 6 in the direction of arrow m.
[0071]
The internal explosive atmosphere B heat-exchanged with the evaporator 6 is heated by the electric device 4 and is convected in the direction of arrow n, so that a convection circulation is formed in the explosion-proof explosion-proof container 2.
[0072]
Support rods 46a and 46a are erected on the left and right of the upper surface of the explosion-proof container 2, and a support base 46 is provided at the upper end thereof. A condenser 8 is disposed on the support base 46. An external fan 41 is provided facing the lower surface of the condenser 8, and the motor part of the external fan 41 is accommodated in the explosion-proof container 2. Therefore, all members that may generate electric sparks are accommodated in the explosion-proof container 2.
[0073]
Refrigerant gas F formed in the evaporator 6_GRises in the direction of arrow c through the outlet tube 12 and enters the condenser 8. External explosive atmosphere A has low temperature T by air conditioning_AHowever, when the air-conditioning power is weak, the condensation efficiency is deteriorated. Therefore, the external explosive atmosphere A is blown into the condenser 8 in the direction of the arrow g by the external fan 41 to increase the condensation efficiency. .
[0074]
Refrigerant gas F_GLoses heat in the condenser 8 and the refrigerant liquid F_LTo change. This refrigerant liquid F_LFlows down in the direction of the arrow a through the introduction pipe 20 and returns to the evaporator 6. In addition, the external explosive atmosphere A that has been heated to a high temperature is cooled by air conditioning. Again, the inside of the explosion-proof container 2 is continuously cooled while repeating this cycle.
[0075]
The cooling device of FIG. 7 also uses a power device called the external fan 41 together with the internal fan 40 to continue the refrigerant circulation based on the temperature difference, and may be called a half power system. As described above, the present invention realizes a cooling device for an electric device that operates in an explosive atmosphere while including a completely non-powered system to a half-powered system.
[0076]
The present invention is not limited to the above-described embodiment, and it goes without saying that various modifications, design changes, and the like within the technical scope of the present invention are included in the technical scope.
[0077]
【The invention's effect】
According to the first aspect of the present invention, since the refrigerant is circulated and driven only by the temperature difference between the inside and outside of the explosion-proof container to cool the inside of the explosion-proof container, an electric device is completely unnecessary as a cooling device, and in an explosive atmosphere A cooling device that is extremely safe to use can be provided. In addition, since the evaporator and condenser are simply placed inside and outside the explosion-proof container, piping is possible, so it can be installed on any explosion-proof container with any structure, and the cooling effect can be demonstrated reliably. .
[0078]
According to the invention of claim 2, since the piping connecting the evaporator and the condenser has explosion-proof strength that does not break even if an explosion occurs inside the explosion-proof container, the flame escapes to the outside through the piping system. There is no danger of doing. In addition, the gap between the piping and the explosion-proof container is designed so that no flame escape occurs, so there is no risk of explosion to the outside even if an explosion occurs in the explosion-proof container. Sex is guaranteed.
[0079]
According to the invention of claim 3, a chimney-like condensing tower is erected on the condenser, and the external explosive atmosphere heat-exchanged by the condenser is discharged from the condensing tower to greatly increase the external explosive atmosphere. Because it circulates, the external explosive atmosphere that has risen in temperature due to heat exchange can be rapidly cooled by air conditioning in the general circulation, maintaining the low temperature of the external explosive atmosphere, and the continuity and stability of the cooling system Ensure sex.
[0080]
According to the invention of claim 4, since the internal fan is disposed in the explosion-proof container, the internal explosive atmosphere is circulated to facilitate heat exchange between the internal explosive atmosphere and the evaporator. The exhaust heat of the electric device can be forcibly transferred to the refrigerant by the evaporator.
[0081]
According to the invention of claim 5, when the temperature difference between the outside and the inside becomes small, a fan is disposed in the vicinity of the condenser to forcibly circulate the external explosive atmosphere, and the external explosive atmosphere and the condenser are By enhancing heat exchange, the cooling efficiency of the electric device can be improved.
[0082]
According to the sixth aspect of the present invention, when the external atmosphere is not air-conditioned and the external temperature becomes high, a compressor is connected between the evaporator and the condenser, and the refrigerant circulation between the evaporator and the condenser and the refrigerant The compression can be forcibly performed, and the inside of the pressure-proof explosion-proof container containing the electric device that generates heat can be forcibly cooled.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of an embodiment of a cooling device for a flameproof container.
FIG. 2 is a schematic cross-sectional view of an embodiment embodying an evaporator and a condenser.
FIG. 3 is a partially enlarged view of FIG. 1;
FIG. 4 is an explanatory diagram of refrigerant operation in the cooling device for the explosion-proof container.
FIG. 5 is a schematic configuration diagram of a cooling device for a flameproof container for a personal computer.
FIG. 6 is a schematic perspective view of a cooling device for an explosion-proof container for a personal computer using a compressor.
FIG. 7 is a schematic configuration diagram of a cooling device for a flameproof container using a fan.
[Explanation of symbols]
2 is an explosion-proof container, 4 is an electric device, 4a is a display, 4b is a personal computer body, 4c is a keyboard, 6 is an evaporator, 6b is an evaporation tower, 8 is a condenser, 8a is a heat radiation fin, 10 is an evaporation tube, 10a is an inclined evaporation pipe, 11 is an endothermic fin, 12 is a discharge pipe, 14 is a discharge valve, 16 is a condensation pipe, 16a is a zigzag condensation pipe, 18 is an introduction valve, 20 is an introduction pipe, 22 is an annular projection, 22a is Through hole, 23 is upper end surface, 24 is a connecting member, 24a is an insertion hole, 26 is an insertion part, 28 is a lid part, 30 is a welded part of a pipe part, 32 is an upper end joint part, 34 is a bubble, 38 is a desk for a personal computer , 40 is an internal fan, 41 is an external fan, 42 is a compressor, 44 is a compression tube, 46 is a support base, 46a is a support rod, A is an external explosive atmosphere, B is an internal explosive atmosphere, D is a gap thickness, G Is a gap, F is a refrigerant, F_GIs refrigerant gas, F_LIs the refrigerant liquid, L is the gap length, T_AIs the external low temperature, T_BIs the internal high temperature.

Claims (2)

Two annular protrusions 22 having a through hole 22a in the center and having a length of 25 mm or more are disposed on and fixed to the lower part of the inner space of the explosion-proof container 2 and the explosion-proof container 2 projecting from the upper wall surface. The electric device 4 is positioned above the electric device 4 and fixed in the interior space of the explosion-proof container 2 with the refrigerant outlet positioned above the refrigerant inlet, and is heat-resistant and explosion-proof by endothermic evaporation of the refrigerant liquid. The evaporator 6 that cools the internal space of the container 2, the insertion part 26, and the lid part 28 are formed. The insertion part 26 is inserted into the through-hole 22 a from the inside of the explosion-proof container 2 with a gap G of 0.2 mm or less. The inner surface 23 on the outer peripheral side of the lid portion 28 is brought into close contact with the end surface 23 of the annular protrusion 22 and the insertion member 24 is formed at the center portion, and the internal temperature of the explosion-proof container 2 by air conditioning. Kept at low temperature It is located in the partial space and is disposed above the explosion-proof container 2, and is inserted into the condenser 8 for condensing the refrigerant gas by heat radiation and the insertion hole 24a of the one connecting member 24 so as to be airtight. While being welded, the end on the inner space side of the explosion-proof container 2 is connected to the refrigerant inlet side of the evaporator 6, and the outer end of the explosion-proof container 2 is connected to the refrigerant outlet side of the condenser 8. The refrigerant introduction pipe 20 and the insertion pipe 24a of the other connecting member 24 are inserted into the insertion pipe 24a and are airtightly welded thereto, and the end portion on the inner space side of the pressure-proof explosion-proof container 2 is the refrigerant of the evaporator 6. The refrigerant outlet pipe 12 is connected to the outlet side, and the outer end of the explosion-proof container 2 is connected to the refrigerant inlet side of the condenser 8, and the condenser 8 is provided above the condenser 8. Exhaust explosive atmosphere that has been heat-exchanged at More, the cooling device of Flameproof爆容device characterized by being configured and a condensation column 8b for circulating external explosive atmosphere. Two annular protrusions 22 having a through hole 22a in the center and having a length of 25 mm or more are disposed on and fixed to the middle part of the interior space of the explosion-proof container 2 and the explosion-proof container 2 projecting from the lower wall surface. The electric device 4 is positioned below the electric device 4 and fixed in the interior space of the explosion-proof explosion-proof container 2 with the refrigerant outlet positioned above the refrigerant inlet. The evaporator 6 that cools the internal space of the container 2, the insertion part 26, and the lid part 28 are formed. The insertion part 26 is inserted into the through-hole 22 a from the inside of the explosion-proof container 2 with a gap G of 0.2 mm or less. The inner surface 23 on the outer peripheral side of the lid portion 28 is brought into close contact with the end surface 23 of the annular protrusion 22 and the insertion member 24 is formed at the center portion, and the internal temperature of the explosion-proof container 2 by air conditioning. Kept at low temperature It is located in the partial space and is disposed above the explosion-proof container 2, and is inserted into the condenser 8 for condensing the refrigerant gas by heat radiation and the insertion hole 24a of the one connecting member 24 so as to be airtight. While being welded, the end on the inner space side of the explosion-proof container 2 is connected to the refrigerant inlet side of the evaporator 6, and the outer end of the explosion-proof container 2 is connected to the refrigerant outlet side of the condenser 8. The refrigerant introduction pipe 20 and the insertion pipe 24a of the other connecting member 24 are inserted into the insertion pipe 24a and are airtightly welded thereto, and the end portion on the inner space side of the pressure-proof explosion-proof container 2 is the refrigerant of the evaporator 6. A refrigerant outlet tube 12 in which the outer end of the explosion-proof container 2 is connected to the refrigerant inlet side of the condenser 8, and the evaporator 6 provided inside the explosion-proof container 6, respectively. An internal fan 40 provided at the bottom and provided inside the explosion-proof container 6 Driven by over motor, the cooling device of Flameproof爆容device, characterized in that it consisted external fan 41. for the blower to the condenser 8.

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