JPS601388A - Cryopump - Google Patents

Abstract

PURPOSE:To prevent the temperature of an adjacent baffle from rising due to the radiant heat of a cooling panel or a baffle being regenerated, by providing an openable/closable shutter between the panel and the buffie or between baffles. CONSTITUTION:To selectively take out gas accumulated in a cryopump, an inlet gate valve 11 is closed and an outlet gate valve 13 are opened first. For example, to selectively take out gas (c) condensed on a panel 10, a shutter 16 is closed and the temperature of the panel is heightened so that the adsorbed gas (c) is separated from the panel and discharged to an outlet duct 14 through the outlet gate valve 13. In that case, since the shutter 16 is kept closed, the radiant heat from the panel 10 during its temperature rise is blocked to prevent the temperature rise of a chevron baffle 9, so that gas (b) condensed on the baffle 9 is kept from being separated therefrom.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a cryopump, and particularly to a cryopump that can selectively recover exhaust gas accumulated within the cryopump.

[Background of the invention]

Figure 1 is a vapor pressure curve showing the relationship between the temperature and vapor pressure of various gases.As can be seen from this graph, by changing the temperature of the multiple stages of cooling surfaces provided in the cryopump, each stage can be The type of gas that is condensed and captured on the cooling surface can be changed.

Fig. 2 shows an example of the conventional structure of a cryopump applying this principle. Cooling pipes 2, 3, and 4 are disposed inside a cryopump case 1, and each coolant 5, 6.7 has been introduced. These cooling pipes 2, 3.
Chevron baffles 8 and 9 and a porous adsorbent panel 10, which are one of the adsorption members, are fixed to each of the adsorption members 4. Further, an inlet duct 12 is connected to the inlet side of the cryopump case l via an inlet gate valve 11, and a cryopump (not shown) provided with an outlet gate valve 13 is connected to the outlet side. It is connected to the outlet duct 14 through the outlet.

In a cryopump with a conventional structure configured in this way, for example, if liquid nitrogen is used as the refrigerant 5 and liquid helium is used as the refrigerants 6 and 7, the Scheffron baffle 8 is 77"
Since the chevron baffle 9 and the porous adsorbent panel 10 are cooled to 4.2' K, the inlet duct 1
2 through the gate pulp 11, for example, water vapor (H2O) a1 hydrogen gas (I-12
) b s Assuming three types of helium gas (He) C, each gas a, b, clr! As shown in the figure, they are condensed and captured on cooling surfaces 8 and 9°lO, respectively. In this case, the outlet side gate pulp 13 connected to the outlet side of the cryopump is closed.

Since this cryopump is a gas storage type pump, the capture performance decreases when the amount of captured gas on the cooling surface exceeds a certain limit, so it is necessary to recover and regenerate the captured gas. At this time, if the captured gas contains harmful gases, or if it becomes necessary to collect and exhaust each gas individually for other reasons, the selective recovery and exhaust operation is performed. This selective recovery exhaust operation means, for example, when recovering only gas C individually, the inlet side gate pulp 11 is closed, the outlet side gate pulp 13 is opened, and then the temperature of the refrigerant 7 is lowered so that the gas C is pumped up from the surface of the panel 10. The temperature is raised until the gas C is liberated, and the gas C is recovered by an exhaust pump (not shown) connected to the outlet duct 14 and beyond.

FIG. 3 shows the state of the above-mentioned selective recovery exhaust gas. According to the conventional cryopump structure, the chevron baffle 9, which has not yet entered the regeneration state, is exposed to the heated panel 10 during regeneration. The temperature rises to some extent due to the heat of the auxiliary agent, and the gas b condensed on this chevron baffle 9
However, there was a drawback that some amount of water was released.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned points, and its object is to provide a cryopump that can perform good selective recovery and exhaust.

[Summary of the invention]

The present invention provides a shutter that can be opened and closed between the cooling panel, which is an adsorption member of the cryopump, and the baffle, or between the buckle, and prevents the temperature of the adjacent buckle from rising due to heat from the secondary agent from the panel or baffle that has entered the regeneration state. Most of all, it was an effort to achieve the intended purpose.

[Embodiments of the invention]

An embodiment of the cryopump according to the present invention will be described below with reference to the drawings.

An embodiment of the present invention is shown in FIGS. 4 and 5.

The same parts as in FIG. 2.3 are indicated by the same numbers or symbols. In Fig. 4, chevron baffles 8, 9fa
Temperature-controlled shutters 15 and 16, which can be opened and closed, are provided between the chevron baffle 9 and the panel 10, respectively. The structure of other parts is the same as the conventional example shown in FIGS. 2 and 3.

The operation of one embodiment of the present invention configured as described above will be described below. During normal exhaustion of the cryopump, exhaust gas flows through the gate pulp 1 which is opened from the inlet side duct 12.
The gas "I bl C" which is a component of the exhaust gas is introduced into the cryopump case 1 through the cooling surface 8.
, condensed and captured on 9.10. At this time, the gate pulp 13 is closed.

When selectively collecting and exhausting the gas accumulated in the cryopump, first, as shown in FIG.
is closed and the exit side gate pulp 13 is opened. - For example, when selectively collecting and exhausting the gas C condensed on the panel 10, the shutter 16 is closed by an opening/closing mechanism (not shown), the temperature of the panel 10 is increased, and the adsorbed gas C is released from the panel 10,
It passes through the outlet side gate pulp 13 and is exhausted to the outlet side duct 14. In this case, since the shutter 16 is closed, the auxiliary heat caused by the temperature rise of the panel 10 is blocked, preventing the temperature rise of the chevron baffle 9. It is possible to prevent the release of the gas b condensed in the full body 9, resulting in a good condition. Enables selective recovery exhaust.

The same applies when selectively collecting and exhausting gas a or b condensed on the Sharon baffle 8t or 9.

〔Effect of the invention〕

As described above, according to the present invention, the shutter prevents the side radiation heat from the panel or baffle of the cryopump that has entered the regeneration state from being transmitted to the adjacent baffle, so that the exhaust gas can be recovered selectively. Exhaust can be carried out, and the effect is great.

[Brief explanation of the drawing]

Fig. 1 is a vapor pressure curve of various gases, Fig. 2 is an explanatory diagram of the operation of a conventional cryopump during pumping, Fig. 3 is an explanatory diagram of the operation during regeneration, and Fig. 4 is an explanatory diagram of the operation of the cryopump according to the present invention. FIG. 5 is an explanatory diagram of the operation during evacuation by one embodiment of the pump, and FIG. 5 is also an explanatory diagram of the operation during regeneration. l... Cryopump case, 5, 6.7... Refrigerant, 8.9"/° chevron baffle, 10... Porous f
=111i Adhesive panel, 11... Inlet side gate pulp, 12... Inlet side duct, 13... Outlet side gate pulp, 14... Outlet side duct, a, b, C... Exhaust gas , 15°16...Shutter. Agent Patent Attorney Akio Takahashi Haku 1 No Shibara Hiki OK) Goe 2 Prisoner 3 No End 40. YS eye

Claims (1)

[Claims] 1. A case into which a gas consisting of a plurality of components is introduced, a plurality of adsorption members provided within this case that each condense and adsorb a different gas component, and a cooling pipe that cools these adsorption members. In the cryopump, a shutter that can be freely opened and closed is provided in each of the adsorption parts, and each shutter is opened when gas is introduced into the case, and the gas adsorbed in any of the adsorption parts is collected. A cryopump characterized in that, when the adsorption member is closed, the adsorption member and the adjoining adsorption member are closed.