JPS58117372A - Superhigh vacuum pump using cryogenic pump and bulk getter pump in combination - Google Patents

Abstract

PURPOSE:To improve the evacuating performance of a vacuum pump and to prolong the service life of the same, by disposing a cryo-pump panel at the central portion in a vacuum tank having a gate valve attached thereto, and disposing a bulk getter pump element around the cryo-pump panel by the intermediary of a shield. CONSTITUTION:A vacuum tank 1 is connected via a gate valve 4 to a vacuum tank 9 to be evacuated, and a cryo-pump panel 2 connected to a cryogenic engine 10 is disposed at the central portion in the tank 1. A shield 5 cooled by cooling pipes 8 is disposed around the cryo-pump panel 2, and a bulk getter pump element 3 is disposed at one side of the shield 5 to locate on the outside thereof. Further, a power supply portion 7 is connected to the element 3 and extended to the outside of the vacuum tank 1. The outer wall of the vacuum tank 1 is also cooled by water cooling pipes 8.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultra-high vacuum pump in which a bulk getter pump element and a cryopond channel are combined in a special arrangement within the same vacuum chamber.

A highly active Zr-A1 alloy is applied to each side of the metal strip to a thickness of e.g.
It is well known that bulk getter pumps coated with Ca and in which the coated Zr--Al alloy layer acts as an active non-evaporable getter are used as vacuum pumps. However, although this pump, like the evaporative getter pump, has a high pumping speed for active gas, it has the disadvantage that it is difficult to pump inert gas. Further, the normal operating temperature of this pump is ≠00° C. to room temperature, and it is necessary to raise the temperature to 730° C. upon activation.

On the other hand, a cryopump of the type that performs an evacuation action by condensing atmospheric component gases on an extremely low mud surface of, for example, 10 mm is also conventionally known.

The invention of the present application combines a noguruku gettuta ponzo that performs exhaust action by absorbing gas with a non-evaporable getter material, and a cryopump that performs exhaust action by condensing atmospheric component gas on the ultra-low mud surface. This is a composite pump arranged in seven vacuum chambers, which significantly extends the pump's lifespan and improves its exhaust performance.

Both the cryopump and the Norukugut pump are exhaust gas storage type (adsorption type), so when a certain amount of gas is adsorbed, the exhaust capacity decreases.

For this reason, it is necessary to carry out a regeneration process to fully recover the pumping capacity, that is, a regeneration action is necessary.

Furthermore, when a cryopump pumps out a large amount of hydrogen, the adsorption equilibrium pressure increases.1-1The pumping speed in an ultra-high negative atmosphere decreases significantly.

Even when operated at room temperature, the pumping speed of the one-flange bulk getter pump is only slightly reduced compared to 11°. ), even if a large amount of II is evacuated, the exhaust I power can be maintained in an ultra-high vacuum. Therefore, by using these two pumps in combination, the time until reactivation can be extended. However, as mentioned above, both /I5 pumps operate under a temperature difference, so if you want to install them in one vacuum chamber, you must provide a shield between them and provide heat isolation, which will reduce efficiency. This is obvious, and therefore it is necessary to install a shield cooled by a water or gas cooling coil.Also, the Norokugetsuda pump absorbs active gas even at room temperature when exposed to atmospheric pressure, so it must be reactivated each time. 'Become sharp. However, the number of times it can be reactivated is limited, so it is preferable to frequently bring the pump chamber to atmospheric pressure.
Since this is not possible, a gate valve is welded to the vacuum chamber to isolate the vacuum chamber to be evacuated from the pump chamber, and when necessary, after creating a vacuum, the gate valve is opened, and both 2j? By operating the pump, the frequency of reactivation of both pumps is reduced, significantly extending the life of both pumps.

The invention will now be described in detail with reference to the drawings.

In the drawing, / is a vacuum chamber in which a pump is placed, and a cryopump channel λ is provided in the center of the vacuum chamber, and seven or several or continuous nodal pump elements 3 are installed on the outer periphery.
and a shield j in the center of both pumps. It is desirable that the outer periphery of the shield j and the outer wall of the vacuum chamber itself be cooled with a water-cooled coil r or the like.

Further, a gate valve V is welded to the vacuum chamber/, and a vacuum chamber to be evacuated is connected to the opposite side of the valve. Note that O is a space in which a Nonotsufuru may be installed, 7 is the power introduction part of the Nonotsufuru element, and 10 is a cryo engine.

[Brief explanation of the drawing]

FIG. 2 is an explanatory diagram of an embodiment of the invention; /...Vacuum chamber, Co...Cryopump panel, 3.
...Bulk getter pump element, G...gate valve, j.
・・Shield ゝ、Otsu・・・Nonotsufa、7...Power introduction section、♂...Cooling・１? , Ri...Vacuum chamber to be evacuated, IO...Cryo engine engraving (no change in content) Procedural amendment (method) February 3, 1981 Mr. Commissioner of the Japan Patent Office■, Small case Display 1980 Patent application @212041 Combined ultra-high vacuum pump 3, relationship with the case of the person making the amendment Patent applicant address 2500 Hagizono, Chigasaki City, Kanagawa Prefecture Name Japan Vacuum Branch Jutsu Co., Ltd. 4, Agent 105 Address: Bussan Pill Annex, 1-15 Nishi-Shinbashi, Minato-ku, Tokyo Telephone: (591) 02616 Contents of amendment: Xerox drawings were extracted at the time of patent application, so the drawings were
) The deceased r2! Ichito in the contents of 100 engravings ``Shi 41-

Claims (1)

[Claims] A cryopump panel is installed in the center of the vacuum chamber which is welded to the gate valve, one of which is attached to the vacuum chamber to be evacuated, and seven or several Norukugetsuta pump elements are placed around it with all shield valves. An ultra-high vacuum pump that combines a cryopump and a bulk getter pump with all the features.