JP4584428B2

JP4584428B2 - Dry air production equipment

Info

Publication number: JP4584428B2
Application number: JP2000262750A
Authority: JP
Inventors: 新治降矢; 充級寺島; 秀敏森本
Original assignee: Ulvac Cryogenics Inc
Current assignee: Ulvac Cryogenics Inc
Priority date: 2000-08-31
Filing date: 2000-08-31
Publication date: 2010-11-24
Anticipated expiration: 2020-08-31
Also published as: JP2002066250A

Description

【０００１】
【発明の属する技術分野】
本発明は、大量のドライエアーを製造する装置に関する。
【０００２】
【従来の技術】
従来、真空処理装置、例えば真空成膜装置に於いては、メンテナンスのために該成膜装置の真空成膜室を大気圧に戻し、該成膜室内の清掃や補修などを人手により行っており、この大気圧に戻すために通常は液体窒素から蒸発した窒素ガスが使用されている。
【０００３】
【発明が解決しようとする課題】
こうした窒素ガスを使用する理由は、真空成膜室などの真空になる空間内に水分を持ち込まないためであるが、該真空成膜室内は酸欠状態にあるため、これを考慮しながら作業者は作業を行わなければならず、窒素ガスを導入して該空間が大気圧になったところで該空間を大気に開放し、酸素が十分に存在するようになってから作業に取りかかることになるので、作業時間が長引く不都合があり、該空間には大気の導入に伴って水分が持ち込まれ、これが該空間の内面に付着して次に該空間を真空に排気するときの時間も長引いてしまう不都合がある。窒素ガスに代え水分の少ないエアーを供給すれば、こうした不都合の解決が可能になる。
【０００４】
本発明は、こうした不都合を解決するための水分の少ないエアーすなわちドライエアーを製造する装置を提供することを目的とするものである。
【０００５】
【課題を解決するための手段】
本発明では、上記の目的を達成するため、真空容器の内部に、機械式冷凍機のコールドヘッドの低温生成部を設けると共に、該真空容器の外部からその内部を循環して再び外部へと延びる往復の空気流通管を設け、該空気流通管の中間部を該低温生成部との間で熱交換して該流通管内の空気を冷却する主熱交換器部に構成し、該空気流通管の主熱交換器部の前後の部分に、該往復の空気流通管の間で熱交換する予備熱交換器部を設け、該予備熱交換器部は内外２重の管からなり、該予備熱交換器部の内管が空気が流出する側の部分の一部を構成し、該予備熱交換器部の外管が空気が流入する側の部分の一部を構成した。該主熱交換器部及び予備熱交換器部に、該真空容器の外部へ連なるドレン管を設けて該空気流通管を流れる空気中から取り除いた水分を排出する。該予備熱交換器に、該空気流通管の復路を流れる空気を加熱するヒーターを設けることで、該流通管から流出するドライエアーの温度を任意に制御できる。該低温生成部を機械式ヘリウム冷凍機のコールドヘッドとこれに取り付けた金属ブロックで構成し、該空気流通管の中間部を該金属ブロックに接触させて該主熱交換器を構成することが好ましい。
【０００６】
【発明の実施の形態】
図面に基づき本発明の実施の形態を説明すると、図１に於いて符号１は真空ポンプ２０により真空に排気された真空容器、符号２は該真空容器１の内部に設けた小型の機械式冷凍機のコールドヘッドやクライオスタッドなどからなる極低温生成部を示し、該極低温生成部２には熱伝導性のよい銅製の例えば２０Ｋｇの金属ブロック１５を一体に取り付けて立体的な極低温面域が得られるようにした。
【０００７】
該真空容器１には、その外部から該容器１の内部を循環して再び外部へと延びて低圧の真空容器１と大気との圧力差により、或いは圧空ポンプ５などにより端部から送り込まれた空気が流通する往復の空気流通管４を設け、該空気流通管４の中間部を該金属ブロック１５にロウ付けその他により接触させることにより主熱交換器部６に構成し、該空気流通管４の内部を流通する空気が冷却されるようにした。該空気流通管４の空気放出側の端部は、真空成膜室などの空間に接続される。
【０００８】
また、該空気流通管４の該主熱交換器部６の流出する側と流入する側の前後の部分４ａ、４ｂに、該往復の空気流通管４の間で熱交換する予備熱交換器部７を設け、該流入する側の部分４ｂを流れる空気の熱により、流出する側の部分４ａに流れる空気の温度を好ましくは室温程度に上昇させて該空間に放出するようにした。図示の例では、該予備熱交換器部７を概略内外２重の管で構成し、その内管が流出する側の部分４ａの一部を構成し、その外管で流入する側の部分４ｂの一部を構成した。これら予備熱交換器部７及び主熱交換器部６に於いては、外部から流入した空気が冷却され、その空気中に含有された水分が凝縮されて除去されるので、その流出側の部分４ａには水分含有率の少ないドライエアーが流れ、同時に流入側の部分４ｂの空気により加熱される。必要な場合には、図示のように該予備熱交換器部７の外部にヒーター８を設けて流出側の部分４ａを流れる空気の温度を必要な温度にまで上昇させるようにし、流通空気から十分な水抜きを行うために該予備熱交換器部７を複数段に設けるようにしてもよい。
【０００９】
該超低温生成部２を構成する小型の１段式の機械式冷凍機２ａのコールドヘッド２ｂを冷凍する原理は図２に示す如くであり、圧縮機ユニット９により圧縮された高圧ヘリウムを、間歇的に開閉する高圧バルブ１０及び蓄冷器１１を介して電動機などで機械的に移動されて膨張したディスプレーサー１２の膨張室１３へ送り込み、サイモン膨張の原理により該膨張室１３の頂部に密接して取り付けた金属ブロック１５を冷却する。そして該ディスプレーサー１２を復動させると共に該低圧バルブ１７を開き、該膨張室１３内の低圧になったヘリウムガスを圧縮機ユニット９に戻す。該金属ブロック１５は例えば１３０Ｋ程度の極低温に冷却され、これに取り付けた空気流通管４の中間部からなる主熱交換器部６も同温度に冷却されることによりその内部を流通する空気が冷却されて水分が除去される。
【００１０】
主熱交換器部６および予備熱交換器部７には、熱交換に伴い流通空気から除去された水を外部へ排除するためのドレン管１４を接続し、必要に応じて該ドレン管１４に設けたドレンバルブ１６を開いて該水を排除するようにした。
【００１１】
図示の２段に予備熱交換部７を設けた例の作動状態を説明すると、該機械式冷凍機２ａを作動させて極低温生成部２及び金属ブロック１５を１３０Ｋに冷却しておき、該空気流通管４の一端を直接大気に或いは圧空ポンプ５を介して接続し、他端の空気放出側を真空成膜室などの空間に向ける。室温の大気を流量制御器により１０ｍ³／時間程度の大量の空気を空気流通管４へ送り込み、その空気はまず２段の予備熱交換部７、７に於いて冷却されると同時に水分が凝縮により取り除かれる。続いて主熱交換器部６に於いて更に極低温に冷却されるために残存する空気中の水分が殆ど完全に取り除かれ、ドライエアーとなって空気流通管４の他端から真空成膜室などの空間に送り込まれる。該主熱交換器部６で空気が例えば１３０Ｋに冷却されると、水の分圧は１０^-8Ｐａ以下のドライエアーになる。
【００１２】
該空間が真空成膜室のように水分を嫌うものである場合、本発明の装置からドライエアーを供給し続けておくことで、該真空成膜室内が酸欠状態にならないので、その内部の保守作業等をその内部が大気圧になったところで直ちに開始することができ、その作業の終了後に該真空成膜室を閉じてその内部を所定の真空に排気するとき、内部に水分が持ち込まれていないため短時間で所定の真空に到達できる。該空気流通管４から吹き出すドライエアーの温度が予定の温度例えば室温よりも低くなりがちのときは、該予備熱交換器部７に設けたヒーター８を作動させて予定温度のドライエアーを放出させることができる。
【００１３】
【発明の効果】
以上のように本発明によるときは、真空容器の内部の極低温生成部と外部から導入した空気流通管の中間部とで主熱交換器部に構成し、該空気流通管の主熱交換器部の前後の部分で予備熱交換器部を構成したので、大量のドライエアーを製造することができ、例えば真空成膜装置などの水分を嫌う装置に供給して迅速に保守を開始し短時間に運転再開状態となし得られて好都合であり、該予備熱交換器部にドレン管やヒーターを設けることで長時間に亘る運転や適温で大量のドライエアーを得ることができる等の効果がある。
【図面の簡単な説明】
【図１】本発明の実施の形態を示す断面線図
【図２】機械式冷凍機の説明図
【符号の説明】
１真空容器、２ａ機械式冷凍機、２極低温生成部、４空気流通管、４ａ・４ｂ部分、６主熱交換器部、７・７予備熱交換器部、８ヒーター、１４ドレン管、１５金属ブロック、２０真空ポンプ、[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for producing a large amount of dry air.
[0002]
[Prior art]
Conventionally, in a vacuum processing apparatus, for example, a vacuum film forming apparatus, the vacuum film forming chamber of the film forming apparatus is returned to atmospheric pressure for maintenance, and the film forming chamber is manually cleaned or repaired. In order to return to the atmospheric pressure, nitrogen gas evaporated from liquid nitrogen is usually used.
[0003]
[Problems to be solved by the invention]
The reason for using such nitrogen gas is to prevent moisture from being brought into a vacuum space such as a vacuum film formation chamber, but the vacuum film formation chamber is in an oxygen deficient state. Work must be performed, and when nitrogen gas is introduced and the space is at atmospheric pressure, the space is opened to the atmosphere, and oxygen begins to exist before work begins. There is an inconvenience that the working time is prolonged, and moisture is brought into the space with the introduction of the atmosphere, which adheres to the inner surface of the space and then the time when the space is evacuated next is also prolonged. There is. Such inconvenience can be solved by supplying air with less moisture instead of nitrogen gas.
[0004]
An object of the present invention is to provide an apparatus for producing air having a low moisture content, that is, dry air, for solving such disadvantages.
[0005]
[Means for Solving the Problems]
In the present invention, for achieving the above object, the interior of the vacuum vessel, provided with a low-temperature generator of the cold head of the mechanical refrigerator, extending back to the outside circulates inside from the outside of the vacuum container A reciprocating air flow pipe is provided, and a main heat exchanger section that cools air in the flow pipe by exchanging heat between the air flow pipe and the low-temperature generation section is formed in the air flow pipe. A preliminary heat exchanger section for exchanging heat between the reciprocating air circulation pipes is provided in the front and rear portions of the main heat exchanger section , and the preliminary heat exchanger section is composed of inner and outer double pipes. The inner pipe of the vessel part constituted a part of the part on the air outflow side, and the outer tube of the preliminary heat exchanger part constituted a part of the part on the air inflow side . The main heat exchanger part and the preliminary heat exchanger part are provided with a drain pipe connected to the outside of the vacuum vessel, and the water removed from the air flowing through the air circulation pipe is discharged. By providing the preliminary heat exchanger with a heater for heating the air flowing in the return path of the air circulation pipe, the temperature of the dry air flowing out from the circulation pipe can be arbitrarily controlled. The low-temperature generator constituted by a metal block attached to the cold head of the mechanical helium refrigerator, it is preferable to form the main heat exchanger and an intermediate portion of the air flow pipe in contact with the metal block .
[0006]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes a vacuum container evacuated by a vacuum pump 20, and reference numeral 2 denotes a small mechanical refrigeration provided inside the vacuum container 1. 1 shows a cryogenic generation unit composed of a cold head, a cryostat, etc. of the machine, and the cryogenic generation unit 2 is integrally attached with a metal block 15 made of, for example, 20 Kg of copper having a good thermal conductivity, and a three-dimensional cryogenic area. Was made available.
[0007]
The vacuum vessel 1 was circulated from the outside through the inside of the vessel 1 and extended to the outside again, and was fed from the end by a pressure difference between the low-pressure vacuum vessel 1 and the atmosphere, or by a pressurized air pump 5 or the like. A reciprocating air circulation pipe 4 through which air circulates is provided, and an intermediate part of the air circulation pipe 4 is formed in the main heat exchanger section 6 by being brought into contact with the metal block 15 by brazing or the like. The air that circulates inside was cooled. An end of the air circulation pipe 4 on the air discharge side is connected to a space such as a vacuum film forming chamber.
[0008]
Further, a preliminary heat exchanger section that exchanges heat between the reciprocating air circulation pipes 4 in the front and rear portions 4 a and 4 b of the air circulation pipe 4 on the outflow side and the inflow side of the main heat exchanger section 6. 7 is provided, and the temperature of the air flowing through the outflow side portion 4a is preferably raised to about room temperature by the heat of the air flowing through the inflow side portion 4b, and discharged into the space. In the example shown in the figure, the preliminary heat exchanger section 7 is constituted by a double pipe that is substantially inside and outside, a part of the part 4a on the side from which the inner pipe flows out, and a part 4b on the side that flows in by the outer pipe. Part of the. In the preliminary heat exchanger section 7 and the main heat exchanger section 6, the air flowing in from the outside is cooled and the moisture contained in the air is condensed and removed, so that the portion on the outflow side The dry air having a low moisture content flows through 4a and is simultaneously heated by the air in the inflow side portion 4b. If necessary, as shown in the figure, a heater 8 is provided outside the preliminary heat exchanger section 7 so as to raise the temperature of the air flowing through the outflow side portion 4a to a necessary temperature. The preliminary heat exchanger unit 7 may be provided in a plurality of stages in order to drain water smoothly.
[0009]
The principle of freezing the cold head 2b of the small one-stage mechanical refrigerator 2a constituting the ultra-low temperature generation unit 2 is as shown in FIG. 2, and high-pressure helium compressed by the compressor unit 9 is intermittently used. It is sent to the expansion chamber 13 of the displacer 12 that has been mechanically moved by an electric motor or the like via the high-pressure valve 10 and the regenerator 11 that open and close to the expansion chamber 13 and is closely attached to the top of the expansion chamber 13 by the principle of Simon expansion. The metal block 15 is cooled. Then, the displacer 12 is moved back and the low pressure valve 17 is opened, and the low pressure helium gas in the expansion chamber 13 is returned to the compressor unit 9. The metal block 15 is cooled to a very low temperature of about 130K, for example, and the main heat exchanger section 6 consisting of an intermediate part of the air circulation pipe 4 attached to the metal block 15 is also cooled to the same temperature, so that the air flowing through the inside is cooled. Cooled to remove moisture.
[0010]
The main heat exchanger section 6 and the preliminary heat exchanger section 7 are connected to a drain pipe 14 for removing water removed from the circulating air due to heat exchange to the outside, and the drain pipe 14 is connected to the drain pipe 14 as necessary. The drain valve 16 provided was opened to remove the water.
[0011]
Explaining the operation state of the example in which the preliminary heat exchange unit 7 is provided in the two stages shown in the figure, the cryogenic generating unit 2 and the metal block 15 are cooled to 130 K by operating the mechanical refrigerator 2a, and the air One end of the flow pipe 4 is directly connected to the atmosphere or via the pneumatic pump 5, and the air discharge side at the other end is directed to a space such as a vacuum film forming chamber. A large amount of air of about 10 m ³ / hour is sent from the room temperature atmosphere to the air circulation pipe 4 by the flow rate controller, and the air is first cooled in the two-stage pre-heat exchangers 7 and 7 and at the same time the moisture is condensed. Removed. Subsequently, since the main heat exchanger section 6 is further cooled to an extremely low temperature, the water in the remaining air is almost completely removed and becomes dry air from the other end of the air circulation pipe 4 to the vacuum film formation chamber. It is sent to such a space. When air is cooled to, for example, 130 K in the main heat exchanger section 6, the partial pressure of water becomes dry air of 10 ⁻⁸ Pa or less.
[0012]
If the space does not like moisture like a vacuum film formation chamber, the vacuum film formation chamber will not be in an oxygen deficient state by continuing to supply dry air from the apparatus of the present invention. Maintenance work etc. can be started immediately when the inside is at atmospheric pressure, and when the vacuum film forming chamber is closed and the inside is evacuated to a predetermined vacuum after the work is finished, moisture is brought into the inside. Therefore, a predetermined vacuum can be reached in a short time. When the temperature of the dry air blown out from the air circulation pipe 4 tends to be lower than a predetermined temperature, for example, room temperature, the heater 8 provided in the preliminary heat exchanger section 7 is operated to release the dry air at the predetermined temperature. be able to.
[0013]
【The invention's effect】
As described above, according to the present invention, the cryogenic temperature generator inside the vacuum vessel and the intermediate part of the air circulation pipe introduced from the outside constitute the main heat exchanger part, and the main heat exchanger of the air circulation pipe Since the pre-heat exchanger part is composed of parts before and after the part, a large amount of dry air can be manufactured. It is convenient that the operation can be resumed, and there is an effect that a large amount of dry air can be obtained at a proper temperature or operation for a long time by providing a drain pipe or a heater in the preliminary heat exchanger section. .
[Brief description of the drawings]
FIG. 1 is a sectional view showing an embodiment of the present invention. FIG. 2 is an explanatory diagram of a mechanical refrigerator.
DESCRIPTION OF SYMBOLS 1 Vacuum container, 2a Mechanical refrigerator, 2 Cryogenic production | generation part, 4 Air distribution pipe, 4a * 4b part, 6 Main heat exchanger part, 7 * 7 Preliminary heat exchanger part, 8 Heater, 14 Drain pipe, 15 Metal block, 20 vacuum pump,

Claims

In the vacuum chamber, provided with a low-temperature generator of the cold head of the mechanical refrigerator, provided a reciprocating air flow pipe extending into the vacuum vessel from outside again circulated therein external air flow pipe The middle portion of the air flow pipe is configured to be a main heat exchanger section that cools the air in the flow pipe by exchanging heat with the low temperature generation section , A preliminary heat exchanger section for exchanging heat between the reciprocating air circulation pipes is provided , the preliminary heat exchanger section is composed of inner and outer double pipes, and the inner pipe of the preliminary heat exchanger section is on the side where air flows out. An apparatus for producing dry air , comprising a part of the part, wherein the outer pipe of the preliminary heat exchanger part constitutes a part of the part into which air flows .

The dry air manufacturing apparatus according to claim 1, wherein a drain pipe connected to the outside of the vacuum vessel is provided in the main heat exchanger section and the preliminary heat exchanger section.

2. The dry air manufacturing apparatus according to claim 1, wherein the preliminary heat exchanger is provided with a heater for heating air flowing through the return path of the air circulation pipe.

The low-temperature generating part is composed of a cold head of a mechanical helium refrigerator and a metal block attached to the cold head, and the main heat exchanger is constructed by contacting an intermediate part of the air circulation pipe to the metal block. The dry air manufacturing apparatus according to claim 1.