JPH0711597B2 - Removal method of powder adhered and accumulated in pneumatic tube - Google Patents
Removal method of powder adhered and accumulated in pneumatic tubeInfo
- Publication number
- JPH0711597B2 JPH0711597B2 JP1072467A JP7246789A JPH0711597B2 JP H0711597 B2 JPH0711597 B2 JP H0711597B2 JP 1072467 A JP1072467 A JP 1072467A JP 7246789 A JP7246789 A JP 7246789A JP H0711597 B2 JPH0711597 B2 JP H0711597B2
- Authority
- JP
- Japan
- Prior art keywords
- powder
- pneumatic tube
- dry ice
- fine particles
- hopper
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Cleaning In General (AREA)
- Air Transport Of Granular Materials (AREA)
Description
この発明は、空気輸送方式により粉末を移送させる気送
管の内面に付着あるいは滞留した粉末を、効果的かつ確
実に除去するための方法に関するものである。 特にこの発明は、水を用いて気送管内を洗浄する方法が
制限される分野、例えばプルトニウムやウラン化合物等
の核燃料物質粉末が気送管内に付着・滞留した場合に、
この粉末を除去、回収する除染方法等に有用である。The present invention relates to a method for effectively and reliably removing powder that has adhered to or accumulated on the inner surface of a pneumatic tube for transferring powder by an air transportation method. In particular, the present invention is a field where the method of cleaning the inside of the air feeding pipe with water is limited, for example, when nuclear fuel substance powder such as plutonium or uranium compound adheres to or remains in the air feeding pipe,
It is useful as a decontamination method for removing and collecting this powder.
空気輸送方式により粉末を気送管内を通して所望箇所へ
移送する場合、気送管内面だけでなく気送のために必要
な設備、例えばサイクロンやホッパー内に粉末が付着あ
るいは滞留し、そのまま運転を続けると気送ラインの閉
塞を生じて工程が停止することもある。 特にプルトニウムやウラン化合物等の核燃料物質を取扱
う場合には、臨界管理や保障措置の観点からその量を常
に把握し、不明在庫を極力少なくする必要があり、気送
管内に付着・滞留する核燃料物質粉末を確実に除去、回
収しなくてはならない。また、使用する核燃料物質を変
更する場合にも、気送管内に残留する粉末を除去してお
かないと品質管理上問題が発生する。 気送管内に付着・滞留した粉末を除去する従来の方法と
しては、除去装置を用いて機械的に除去する方法、水ま
たはその他の液体を気送管内に流して洗浄する方法、あ
るいは砂等を圧空等により気送管内に吹込んで洗浄する
方法がある。When the powder is transferred to the desired location through the pneumatic tube by the air transportation method, the powder adheres to or stays not only on the internal surface of the pneumatic tube but also on the equipment necessary for pneumatic transportation, for example, cyclone or hopper, and the operation is continued as it is. The process may stop due to blockage of the pneumatic line. Especially when dealing with nuclear fuel materials such as plutonium and uranium compounds, it is necessary to constantly grasp the amount from the viewpoint of criticality control and safeguards, and to reduce the unknown inventory as much as possible. The powder must be reliably removed and collected. Further, even when changing the nuclear fuel material to be used, quality control problems occur unless the powder remaining in the pneumatic tube is removed. As a conventional method for removing the powder adhering to and staying in the pneumatic tube, a mechanical removal method using a removing device, a method of flowing water or other liquid into the pneumatic tube for washing, or sand is used. There is a method of cleaning by blowing it into the pneumatic tube with compressed air or the like.
しかしながら、上記したような機械的除去方法は、気送
管の曲りの部分における除去が困難であったり、気送管
が長い場合には除去装置が大型化せざるを得ず、さらに
は気送のために必要な設備であるサイクロンやホッパー
内に粉末の除去ができないといった欠点がある。 また核燃料物質粉末の気送管の場合には、気送管内に付
着・滞留している粉末が核物質であるため水などの液体
による洗浄は制限され、さらに固体を吹込む方法におい
ては、その固体の回収および核燃料物質粉末との分離の
点で困難を生じる。 そこでこの発明の目的は、上述した従来技術における欠
点を解消し、気送管内に付着・滞留した粉末の除去を、
気送管の形状や長さに関係なく効果的かつ確実に行うこ
とができる方法を提供することである。 さらにこの発明の目的は、洗浄媒体として水などの液体
を用いることなく、さらには回収が困難でかつ粉末との
分離が困難な固体洗浄媒体を用いることなく、気送管内
に付着・滞留した粉末を確実に除去、回収することがで
きる方法を提供することである。 この発明のもう１つの目的は、核燃料物質粉末の気送管
内さらには気送のために必要なサイクロンやホッパー内
に付着・滞留した粉末を効果的に除去、回収して除染す
る方法を提供することである。However, the mechanical removal method as described above is difficult to remove in the bent portion of the air feeding tube, or the removal device has to be increased in size when the air feeding tube is long. Therefore, there is a drawback that the powder cannot be removed in the cyclone and the hopper, which are necessary facilities. Further, in the case of the pneumatic tube of the nuclear fuel material powder, since the powder adhering and staying in the pneumatic tube is the nuclear material, washing with a liquid such as water is limited. Difficulties arise in terms of solid recovery and separation from nuclear fuel material powder. Therefore, an object of the present invention is to eliminate the above-mentioned drawbacks in the conventional technique, and to remove the powder adhered and accumulated in the pneumatic tube.
An object of the present invention is to provide a method that can be effectively and reliably performed regardless of the shape and length of the pneumatic tube. Further, the object of the present invention is to use the powder adhered and stayed in the pneumatic tube without using a liquid such as water as a cleaning medium, and further without using a solid cleaning medium which is difficult to collect and is difficult to separate from the powder. It is an object of the present invention to provide a method capable of reliably removing and recovering. Another object of the present invention is to provide a method for effectively removing and recovering powder adhering to and accumulating in a cyclone or a hopper required for pneumatic transportation of nuclear fuel material powder and further for decontamination. It is to be.
すなわちこの発明による気送管内付着・滞留粉末の除去
方法は、気送管内にドライアイス微粒子を気送すること
によって、該気送管内面に付着あるいは滞留した粉末を
除去することを特徴とするものである。That is, the method for removing the powder adhering to and staying in the pneumatic tube according to the present invention is characterized in that the powder adhering to or staying on the inner surface of the pneumatic tube is removed by pneumatically feeding dry ice fine particles into the pneumatic tube. Is.
圧空等で気送管内に気送されたドライアイス微粒子は、
その衝撃力で気送管内あるいはサイクロンやホッパー内
に付着あるいは滞留している粉末を効果的に剥離、除去
する。 ドライアイス（固体二酸化炭素）は、比重が1.56で硬度
は低いため、これによる衝撃力を気送管内面やサイクロ
ン、ホッパー等の機器類に与えても、損傷を与える心配
はない。 ドライアイス微粒子は気送管内を粉末と同様な経路を経
て移動するため、粉末が付着・滞留しやすい部分にも集
中的に作用して、そこに付着・滞留している粉末を確実
に除去することができる。 また、気送管内に単に付着・滞留しただけでなくその場
所で固化して水洗浄では除去できないような粉末でも、
ドライアイス微粒子の衝撃力により効果的に剥離、除去
できる。 除去された粉末はドライアイス微粒子と共に取出すだけ
で、ドライアイス微粒子は昇華してしまうため、ドライ
アイスと粉末とを分離する作業を行わずとも、除去した
粉末を確実に回収することができる。またドライアイス
微粒子が気送管内に残留した場合でも、ドライアイスは
その場で昇華するため不純物として気送管内に残ること
はない。The dry ice particles that have been pneumatically transported into the pneumatic tube by compressed air,
The impact force effectively separates and removes the powder adhering to or staying in the pneumatic tube, cyclone or hopper. Since dry ice (solid carbon dioxide) has a specific gravity of 1.56 and a low hardness, there is no risk of damaging it even if the impact force is applied to the inner surface of the pneumatic tube, cyclones, hoppers, and other devices. Since the dry ice particles move in the pneumatic tube through the same path as the powder, they also act intensively on the part where the powder easily adheres and stays, and reliably removes the powder that adheres and stays there. be able to. In addition, even if the powder not only adheres and stays in the pneumatic tube but solidifies at that location and cannot be removed by water washing,
It can be effectively peeled and removed by the impact force of dry ice particles. The removed powder is simply taken out together with the dry ice fine particles, and the dry ice fine particles are sublimated. Therefore, the removed powder can be reliably recovered without performing the operation of separating the dry ice and the powder. Even if the dry ice fine particles remain in the air delivery tube, the dry ice does not remain in the air delivery tube as an impurity because it sublimes on the spot.
添付の図面は、一般的な核燃料物質粉末の気送管装置の
概略図である。通常の使用方法では、グローブボックス
Ａ内の粉末１を気送管２を介してグローブボックスＢ内
に設置したサイクロン３へ気送し、ここで固−気分離を
行い、固体の粉末のみホッパー４内に溜める。その後ホ
ッパー４より粉末を取出して引続く次のプロセス処理装
置（図示せず）へ移送する。気送管２を介しての粉末１
の気送は、グローブボックスＣ内に設置したブロアー５
により気送管２およびサイクロン３、ホッパー４内を負
圧にすることによりなされる。図中、番号６はサイクロ
ンに内装されたフィルターであり、番号２′は気送管の
分岐管である。この分岐管２′からは、別のグローブボ
ックス（図示せず）からの別の種類または同種の核燃料
物質粉末が気送され混合される。かような気送工程を実
施する過程で、気送管2,2′内面、サイクロン３内面、
ホッパー４内面、フィルター６表面等に粉末が付着ある
いは滞留する。 このような付着・滞留粉末の除去をこの発明の方法に従
って実施する場合には、粉末１に代えて単にドライアイ
ス微粒子を粉末と同様にして気送管内に気送すれば良
い。気送されたドライアイス微粒子は、粉末と同じ経路
を経て、気送管２、サイクロン３、ホッパー４、フィル
ター６を移送され、従って、粉末が特に付着・滞留しや
すい部分にドライアイス微粒子が気送され、効果的かつ
確実に付着・滞留粉末を除去する。 このとき使用するドライアイス微粒子の大きさは、気送
されうる寸法であればよく、一般的には直径2mm程度に
予め調製した微粒子が好ましく使用できる。 除去された粉末は、ドライアイス微粒子との混合物とし
てホッパー４から取出したのちドライアイス微粒子のみ
を昇華させることにより、回収することができる。ある
いはまた、除去された粉末とドライアイス微粒子との混
合物をホッパー４から取出すことなく、ホッパー内でド
ライアイス微粒子が昇華するのをまってもよい。 実施例 添付図面に示したような気送管装置のモックアップ機を
作製し、酸化アルミニウム粉末（Al2O3,粒度＃8000,平
均粒径１μ）を気送した。次いで、気送管、サイクロ
ン、ホッパーに残留した酸化アルミニウム粉末を除去す
るために、直径約2mmのドライアイス微粒子を気送管に
気送した。残留粉末の回収率を測定した結果を下表に示
す。 １回目 ２回目 粉末気送量 1000 ｇ 1000 ｇ 粉末付着量 587.9g 431.3g ドライアイス気送量 2200 ｇ 1000 ｇ 付着粉末回収量 537.5g 426.8g 回収率 91 ％ 99 ％ これらの結果からわかるように、１回目は91％、２回目
は99％、２回の平均で95％の回収率で、気送管、サイク
ロン、ホッパー内に付着・滞留した粉末を除去、回収す
ることができた。The accompanying drawings are schematic views of a general nuclear fuel material powder pneumatic tube device. In a normal use method, the powder 1 in the glove box A is pneumatically sent via a pneumatic tube 2 to a cyclone 3 installed in the glove box B, where solid-gas separation is performed, and only the solid powder hopper 4 is used. Store inside. After that, the powder is taken out from the hopper 4 and transferred to the subsequent process processing device (not shown). Powder 1 via pneumatic tube 2
Blower 5 installed in the glove box C
The inside of the pneumatic tube 2, the cyclone 3, and the hopper 4 are made to have a negative pressure. In the figure, reference numeral 6 is a filter installed in the cyclone, and reference numeral 2'is a branch pipe of the pneumatic tube. From this branch pipe 2 ′, another kind or the same kind of nuclear fuel material powder from another glove box (not shown) is pneumatically fed and mixed. In the process of performing such an air feeding process, the inner surfaces of the air feeding pipes 2 and 2 ′, the inner surface of the cyclone 3,
The powder adheres to or accumulates on the inner surface of the hopper 4, the surface of the filter 6, and the like. When such adhering / retaining powder is removed according to the method of the present invention, instead of the powder 1, dry ice fine particles may be simply fed into the air feeding tube in the same manner as the powder. The dry ice fine particles sent by air are transferred through the air feeding pipe 2, the cyclone 3, the hopper 4, and the filter 6 through the same route as that of the powder, so that the dry ice fine particles become hot to the portion where the powder is particularly likely to adhere and stay. Delivered and effectively and surely removing adhered and accumulated powder. The size of the dry ice fine particles used at this time may be any size as long as it can be transported by air, and generally fine particles prepared in advance with a diameter of about 2 mm can be preferably used. The removed powder can be recovered by extracting it from the hopper 4 as a mixture with the dry ice particles and then sublimating only the dry ice particles. Alternatively, the dry ice fine particles may be allowed to sublime in the hopper without taking out the mixture of the removed powder and the dry ice fine particles from the hopper 4. Example A mock-up machine of a pneumatic tube device as shown in the attached drawings was prepared, and aluminum oxide powder (Al 2 O 3 , grain size # 8000, average grain size 1 μ) was pneumatically transported. Next, in order to remove the aluminum oxide powder remaining on the air feeding tube, cyclone, and hopper, dry ice fine particles having a diameter of about 2 mm were air fed to the air feeding tube. The results of measuring the recovery rate of the residual powder are shown in the table below. As can be seen from the first second powder pneumatically weight 1000 g 1000 g powder coating weight 587.9g 431.3g dry ice vapor feed amount 2200 g 1000 g adhering powder recovery amount 537.5g 426.8g recovery 91% 99% These results, With the recovery rate of 91% in the first time and 99% in the second time, and an average of 95% in the second time, it was possible to remove and collect the powder adhering and staying in the pneumatic tube, cyclone, and hopper.
上述したところからわかるようにこの発明による気送管
内の付着・滞留粉末の除去方法によれば、次のような優
れた効果を得ることができる： １）粉末の代わりにドライアイス微粒子を気送管に気送
するだけであるため、作業が極めて簡単である。 ２）既設の設備を改造あるいは追加する必要がない。 ３）使用するドライアイスは比重が1.56であり、硬度は
低いため、気送管内面を損傷する心配はない。 ４）粉末が気送管内を気送されるのとまったく同じ経路
を経てドライアイス微粒子が気送されるため、粉末が付
着・滞留しやすい部分を集中的に除去することができ
る。 ５）気送管内で付着、固化してしまい水洗浄だけでは除
去できないような固着粉末でも効果的に剥離、除去する
ことができる。 ６）除去された粉末とドライアイスとの混合物からドラ
イアイスのみが昇華するため、粉末とドライアイスを分
離する作業が不要となる。 ７）気送管内さらには関連機器内にドライアイス微粒子
が残留しても昇華してしまうため、不純物として残るこ
とがない。従って、ドライアイスを取出すために機器類
を分解する必要がない。 ８）特に核燃料物質粉末の気送管やサイクロン、ホッパ
ーをこの発明方法により洗浄する場合には、粉末取出し
作業に際してサイクロンやホッパーを分解する必要がな
いから、作業効率の向上および被爆低下が図れる。As can be seen from the above, according to the method for removing the adhered / retained powder in the pneumatic tube according to the present invention, the following excellent effects can be obtained: 1) The dry ice fine particles are pneumatically transferred instead of the powder. It is extremely easy to work because it is only pneumatically fed to the pipe. 2) There is no need to modify or add existing equipment. 3) The dry ice used has a specific gravity of 1.56 and low hardness, so there is no risk of damaging the inner surface of the pneumatic tube. 4) Since the dry ice fine particles are transported through the same path as the powder is transported in the pneumatic tube, it is possible to intensively remove the portion where the powder tends to adhere and stay. 5) The adhered powder that adheres and solidifies in the pneumatic tube and cannot be removed only by washing with water can be effectively peeled and removed. 6) Since only dry ice sublimes from the mixture of the removed powder and dry ice, the work of separating the powder and dry ice becomes unnecessary. 7) Even if the dry ice fine particles remain in the pneumatic tube and in the related equipment, they sublimate and do not remain as impurities. Therefore, there is no need to disassemble the equipment to remove the dry ice. 8) In particular, when cleaning the pneumatic pipe of the nuclear fuel material powder, the cyclone and the hopper by the method of the present invention, it is not necessary to disassemble the cyclone and the hopper during the powder extraction work, so that the working efficiency can be improved and the exposure can be reduced.
添付図面は一般的な核燃料物質粉末の気送管装置の概略
説明図である。 １……粉末、2,2′……気送管、３……サイクロン、４
……ホッパー、A,B,C……グローブボックス。The attached drawings are schematic illustrations of a general pneumatic tube device for nuclear fuel material powder. 1 ... Powder, 2,2 '... Pneumatic tube, 3 ... Cyclone, 4
…… Hopper, A, B, C …… Glove box.
Claims (3)
ことによって、該気送管内面に付着あるいは滞留した粉
末を除去することを特徴とする気送管内付着・滞留粉末
の除去方法。1. A method for removing powder adhering to and staying in a pneumatic tube, which comprises removing powder adhering to or accumulating on the inner surface of the pneumatic tube by pneumatically feeding dry ice fine particles into the pneumatic tube.
微粒子を気送することによって、該気送管内面に付着あ
るいは滞留した粉末を除去し該ドライアイス微粒子と共
に回収することを特徴とする気送管内の除染方法。2. A gas which is characterized in that dry ice fine particles are pneumatically fed into an air feeding pipe of a nuclear fuel material powder to remove powder adhering to or staying on the inner surface of the air feeding pipe and to collect the dry ice fine particles together with the dry ice fine particles. Decontamination method inside the pipe.
いる請求項１あるいは２記載の方法。3. The method according to claim 1, wherein dry ice fine particles having a diameter of about 2 mm are used.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1072467A JPH0711597B2 (en) | 1989-03-24 | 1989-03-24 | Removal method of powder adhered and accumulated in pneumatic tube |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1072467A JPH0711597B2 (en) | 1989-03-24 | 1989-03-24 | Removal method of powder adhered and accumulated in pneumatic tube |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02249999A JPH02249999A (en) | 1990-10-05 |
| JPH0711597B2 true JPH0711597B2 (en) | 1995-02-08 |
Family
ID=13490143
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1072467A Expired - Fee Related JPH0711597B2 (en) | 1989-03-24 | 1989-03-24 | Removal method of powder adhered and accumulated in pneumatic tube |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0711597B2 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2335154B (en) * | 1998-03-09 | 2002-10-30 | System Hygienics Ltd | A method of cleaning the inside surface of ducts |
| JP5905204B2 (en) * | 2011-03-31 | 2016-04-20 | 大和製衡株式会社 | Powder conveying system |
| CN103381966B (en) * | 2013-07-12 | 2016-02-24 | 信易电热机械有限公司 | Namely type of inserting cuts materials device and using method thereof |
| FR3121365A1 (en) * | 2021-04-02 | 2022-10-07 | Commissariat A L'energie Atomique Et Aux Energies Alternatives | PROCESS FOR TRANSPORTING POWDERS |
-
1989
- 1989-03-24 JP JP1072467A patent/JPH0711597B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02249999A (en) | 1990-10-05 |
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