JPH03105083A - Cryopump - Google Patents

Abstract

PURPOSE:To shorter the regeneration time by installing a cryopump body equipped with a cryopanel separately from a refrigerator, installing a cooling coil which is constituted so that the coolant supplied from the refrigerator circulates onto the cryopanel, and by installing an open/closing valve in the coolant feeding circuit and the return circuit of the refrigerator. CONSTITUTION:As for a cryopump body 1 equipped with an exhaust port 12 having a buffle 12, cryopanels 3a and 3b are installed inside, and a refrigerator 4 is arranged separately from the cryopump body 1. The refrigerator 4 is equipped with the first stage and second stage cold heads 6a and 6b for expanding the coolant of He gas supplied from a compressor 5. Cooling coils 7a and 7b wound onto respective cryopanels 3a and 3b are connected to the feeding circuits 10a and 10b and the return circuits 11a and 11b of the refrigerator 4 through connecting passages 8a and 8b installed on the side part of the pump body 1, and the opening/closing valves 13-15 are interposed in the respective feeding circuits 10a and 10b and return circuits 11a and 11b.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a cryopump whose regeneration time can be easily shortened.

(Prior Art) Conventionally, cryopumps, for example, as shown in Figure 1,
Several cryopanels C are provided in a cryopump body b equipped with an exhaust port a, and the cryopanels C are connected to a refrigerator d.
It is generally equipped with a configuration for cooling and exhausting gas by a cold head e. This type of bomb is IOK ~ 10
Gas molecules are condensed and adsorbed on a cryopanel at a low temperature of 0K, and then exhausted.

As described above, since the cryopump is a reservoir type pump, when a certain amount of gas is evacuated, a regeneration operation is required to discharge the condensed and adsorbed gas to the outside of the bomb. This operation evaporates the gas that is condensed and adsorbed on the cryopanel.
This is done by vaporizing it and exhausting it with a roughing bomb. Even when the cryopanel reaches room temperature, the water is still liquid, and when it is pumped out with a roughing bomb, it turns into ice.
A cryopump that pumps out a lot of water takes a long time to regenerate. In order to perform the regeneration operation in a short time, various measures have been taken, such as energizing a heater wrapped around the bomb body to heat it, and purging heated nitrogen into the bomb.

(Problem to be solved by the invention) When heating the pump body and purge gas during the regeneration operation of a conventional cryopump, the heat resistance of the refrigerator d is low, so it can only be heated to about 70°C, and it is difficult to regenerate moisture etc. takes a lot of time.

In addition, with normal cryopumps, the heat generated by regeneration
It takes a lot of time to heat up not only the cryopanel but also the cold head of the refrigerator. Furthermore, it takes a lot of time to cool down the cryopump for reactivation because it is necessary to cool both the cold head of the refrigerator and the cryopanel, which have been heated up. At least several hours are required for this temperature increase and recooling.

The long time required for this regeneration operation is the reason why the use of cryopumps is limited, despite the fact that higher quality vacuum can be obtained.

In the present invention, the cryopanel is heated at 150°C to 250°C during regeneration.
By raising the temperature to ℃ or higher, it promotes the evaporation of condensed and adsorbed non-exhaust gas, which not only shortens the time for regenerating exhaust gas, but also significantly increases the time for temperature raising and recooling of the cryopanel, especially for recooling. The purpose is to provide a shortened Taraio Bomb.

(Means for Solving the Problems) The present invention provides a cryopanel in a cryopump body equipped with an exhaust port, and cools the cryopanel with a refrigerator to condense, adsorb and exhaust gas. The cryopump body and the refrigerator are installed separately, and a cooling coil through which refrigerant from the refrigerator circulates is attached to the Taraiover panel, and heat is supplied to the cooling coil from a compressor installed outside the cryopump body. A supply circuit for supplying refrigerant via an exchanger and the refrigerator, and a return circuit for returning refrigerant from the cooling coil to the compressor via the heat exchanger are connected, and further connected to the supply circuit and the return circuit. The above object is achieved by providing an on-off valve that stops the circulation of refrigerant to the cooling coil.

(Function) A refrigerant such as He gas is guided from the refrigerator into the bomb body installed separately from the refrigerator, circulates through the cooling coil attached to the cryopanel inside the bomb body, and then returns to the refrigerator. Returning, the cryopanel condenses and adsorbs the gas molecules flowing in from the exhaust port of the bomb body and performs the exhaust operation,
For the subsequent heating for regeneration exhaust, since the refrigerator with a low heat-resistant temperature is separated from the pump body, the exhaust port of the body is closed and the inside of the body is connected to a vacuum bomb, and the whole body is heated. For example, 250
This can be done by heating to temperatures above ℃. During this heating, the refrigerator is not heated, and there is no need to remove or disassemble it, resulting in good workability. This high temperature heating allows the regeneration operation to be completed in a short time.

Furthermore, in this cryopump, only the cryopanel to which the cooling vibrator is attached is heated and recooled, so that the heating and cooling times can be shortened.

Furthermore, by operating the on-off valve of the refrigerant circulation system,
The refrigerator and refrigerant circulation system can be operated and heated for regeneration while being kept at a low temperature, and low-temperature refrigerant can be circulated to the cryovanel from the start of recooling.
The time required to recool the cryopanel can be significantly shortened.

(Example) An example of the present invention will be described based on FIG.
In the figure, the code (1) is the cryopump body equipped with the exhaust port (2), (3a) and (3b) are the cryovanels, and (4)
shows a refrigerator equipped with a first-stage cold head (6a) and a second-stage cold head (6b) that expand the He gas refrigerant sent out from the compressor (5).The refrigerator (4> is the cryopump main body) The cooling coils (7a) (7b), which are provided separately from the bomb body (1) and wrapped around each cryovanel (3a) (3b), are connected to the bomb body (1).
It was connected to the refrigerator 4) through a connecting passage (8a) <8b) provided on the side of the refrigerator.

To explain this more specifically, one cooling coil (7
a) includes a compressor (5) to a first heat exchanger (9);
> and a supply circuit (10a) that supplies refrigerant via the first stage cold head (6a) of the refrigerator (4), and a supply circuit (10a) that supplies refrigerant from the cooling coil (7a) to the compressor via the first heat exchanger (9). A return circuit (11a) is connected to return the refrigerant to the compressor (5).The other cooling coil (7b) is connected to the first heat exchanger (9) and the second heat exchanger (9) from the compressor (5).
a supply circuit (10b) for supplying refrigerant through the heat exchanger a and the second stage cold head (6b) of the refrigerator (4); 1
A return circuit (llb) is connected which returns the refrigerant to the compressor (5) via the heat exchanger (9).

Each external supply circuit (10a) (1) of the bomb body (1)
0 b) and return circuit (11 a) (11 b) l
: C. An on-off valve (13 (14) as ae) and a bypass valve 071 (181) are provided to control the flow of refrigerant.

(+!EI is the first and second stage cold head (8a) (6b) of the refrigerator (4) and the first and second heat exchanger (9)
(I2a1■ is a cover that covers the IZ, and its interior is evacuated to a vacuum state if necessary.I2a1■ is the connection passage (8a) (
The closing member 8b) is a baffle.

In addition, each heat exchanger (9) (in 121, the return circuit (
The low-temperature refrigerants 11a and 11b act to cool the higher-temperature refrigerants in the supply circuits 10a and 10b through heat exchange.

The illustrated cryopump performs heating for regeneration, but in these cases, as shown in the third figure, the exhaust port (2) of the bomb body (1) is closed with a container ■, and the gate valve ■
Connect the turbo molecular bomb ■ and the oil rotary bomb Q@ to the pump body <1) through the
cover with Then, the compressor {5} is operated, and the refrigerator (4), refrigerant supply circuit (10a) (10b), return circuit (lla) (llb), heat exchanger (9) (121 is the on-off valve while maintaining the low temperature) (+3 a4 (Close IS1ae, open bypass valve 0″r) (to), and close pump body (1
) and operate the heating element ■ to remove the pump body (1).
Heat the inside to 150°C to 250°C or higher. As a result, the gas molecules condensed and adsorbed on the cryopanels (3a) (3b) are evaporated and vaporized by the pump Q3QΦ
Regenerate the cryopump by removing the

Since the bomb body (1) is separated from the refrigerator (4), the pump body (1) can be heated to a high temperature regardless of the refrigerator (4), which has a low heat-resistant temperature, and has a sufficient temperature. and regenerative exhaust can be performed in a short time.

The cryopump produces a cryovanel (3a>(3b)
) to re-cool and evacuate, use the bypass valve (1
7) While closing ae, open and close the on-off valve (13(IΦ(+51
When the ae is gradually opened so that an appropriate amount of refrigerant flows, the He gas sent out from the compressor (5) is cooled to the level of, for example, IOOK in the first heat exchanger (9), and the He gas is cooled to the level of IOOK, for example, in the first stage of the refrigerator <4>. It is supplied to the cooling coil (7a) of the cryovanel (3a) via the cold head (6a), and is cooled to a level of, for example, 15K in the second heat exchanger (121), and is then supplied to the second stage cold of the refrigerator (4). head(
The cooling coil (6b) of the cryopanel (3b) is
7b). As mentioned above, the refrigerator (4) and the refrigerant circulation system are already at a low temperature, and the recooling time can be greatly shortened compared to a normal cryopump that cools down the refrigerator together with the refrigerator from a high temperature. By this re-cooling, each cryopanel (3a) (3b) is
The refrigerant is cooled by the heat exchanger (9) and condenses and adsorbs gas molecules flowing in from the exhaust port (2).The refrigerant returning from each cooling coil (7a) (7b) is The supply circuits (10 a) (10 b) ) while cooling the refrigerant.

In addition, regarding the compressor (5), the refrigerator (4)
A refrigerant circulation system and two separate compressors may also be used.

(Effects of the Invention) As described above, according to the present invention, the cryopump main body equipped with the Talaiopanel is provided separately from the refrigerator, and the cryopanel is provided with a cooling coil through which refrigerant from the refrigerator circulates, and the cooling coil A supply circuit that supplies refrigerant from a compressor installed outside the cryopump body via a heat exchanger and a refrigerator, and a return circuit that returns refrigerant from the cooling coil to the compressor via the heat exchanger are connected, Furthermore, the supply circuit and return circuit are equipped with on-off valves that stop the circulation of refrigerant to the cooling coil.
By operating the refrigerator and refrigerant circulation system, it is possible to heat the cryopump body to a relatively high temperature while it is still cooled, allowing regenerative exhaust operations to be performed in a short time, and subsequent recooling time can be greatly shortened. There is an effect.

In this way, the time required for a series of regeneration operations such as stopping the bomb, raising the temperature, evacuation, and regenerating cooling, which is the biggest drawback of cryopumps, can be greatly shortened.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a conventional example, FIG. 2 is a sectional view of an embodiment of the present invention, and FIG. 3 is an explanatory diagram of a heating operation for regenerating a cryopump of the present invention. (1>...Cryopump body (2)...Exhaust port (3a) (3b)...Cryopanel (4)...
Freezer (5)...Compressor (7a) (7b)...Cooling coil (9) (121...Heat exchanger (10a) (10b) - Supply circuit (11a) (1l b) )-return circuit aga as (151 ae-...open/close valve (+7)
(+8... Bypass valve Q3QΦ... 3 people other than regenerative exhaust pump

Claims (1)

[Claims] 1. A cryopanel is provided in a cryopump body equipped with an exhaust port, and the cryopanel is cooled by a refrigerator to condense, adsorb and exhaust gas,
The cryopump main body and the refrigerator are provided separately, and a cooling coil through which refrigerant from the refrigerator circulates is attached to the cryopanel, and a heat exchanger is installed in the cooling coil from a compressor provided outside the cryopump main body. A supply circuit for supplying refrigerant through the refrigerator and the refrigerator, and a return circuit for returning refrigerant from the cooling coil to the compressor via the heat exchanger are connected, and the cooling is further connected to the supply circuit and the return circuit. A cryopump characterized by being equipped with an on-off valve that stops the circulation of refrigerant to the coil.