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US 5,517,823 AGranted
Pressure controlled cryopump regeneration method and system
AssigneeHelix Technology Corporation
InventorsBruce R. Andeen, Gerald J. Fortier, Allen J. Bartlett, Michael J. Eacobacci, Philip C. Lessard
Life of this patent
Estimating the term…
Abstract
In a subatmospheric regeneration process, a relief valve and a roughing valve are coupled in parallel to a common roughing pump. During regeneration, the cryopump is warmed to release gases from cryopump stages. The relief valve opens at a first cryopump pressure level less than a predetermined maximum pressure. The maximum pressure is subatmospheric. The relief valve closes when the cryopump pressure drops below a second cryopump pressure level. Pressure in a line between the relief valve and the roughing pump is monitored to control the opening of the roughing valve to the roughing pump.
Claims19
A method of regeneration of a cryopump comprising:
- warming the cryopump to release gases from the cryopump;
- opening a relief valve from the cryopump to a roughing pump at a first cryopump pressure level less than a predetermined maximum pressure;
- maintaining the relief valve open until the cryopump is sufficiently empty of released gases;
- closing the relief valve when the cryopump pressure drops below a second cryopump pressure level;
- opening a roughing valve from the cryopump to the roughing pump after the relief valve closes.
2 more elements
A method of regeneration of a cryopump comprising:
- warming the cryopump to release gases from the cryopump;
- opening a relief valve from the cryopump to a vacuum pump at a first cryopump pressure level less than a predetermined maximum pressure;
- maintaining the relief valve open until the cryopump is sufficiently empty of released gases;
- closing the relief valve when the cryopump pressure drops below a second cryopump pressure level;
- monitoring pressure in a line between the relief valve and the vacuum pump;
- opening a roughing valve from the cryopump to a roughing pump after the line pressure drops sufficiently to indicate that the relief valve has closed,
3 more elements
A cryopump comprising:
- a cryopump chamber;
- a warm purge gas valve for applying purge gas to the cryopump chamber;
- a roughing valve for coupling the cryopump chamber to a roughing pump;
- a self-actuating relief valve for coupling the cryopump chamber to the roughing pump, the relief valve opening to the roughing pump at a first cryopump pressure level less than a predetermined maximum pressure and closing when the cryopump pressure drops below a second cryopump pressure level;
- and
- an electronic controller for controlling the purge gas valve and roughing valve, the controller being programmed to control a regeneration process by:
- warming the cryopump to release gases from the cryopump;
- opening the roughing valve to the roughing pump after the relief valve has closed.
5 more elements
A cryopump comprising:
- a cryopump chamber;
- a warm purge gas valve for applying purge gas to the cryopump chamber;
- a roughing valve for coupling the cryopump chamber to a roughing pump;
- a self-actuating relief valve for coupling the cryopump chamber to a vacuum pump, the relief valve opening to the vacuum pump at a first cryopump pressure level less than a predetermined maximum pressure and closing when the cryopump pressure drops below a second cryopump pressure level;
- a pressure sensor for monitoring pressure in a line between the relief valve and the vacuum pump;
- and
- an electronic controller for controlling the purge gas valve and roughing valve, and for monitoring the pressure sensor, the controller being programmed to control a regeneration process by:
- warming the cryopump to-release gases from the cryopump;
- monitoring pressure in a line between the relief valve and the vacuum pump;
- opening the roughing valve to the roughing pump after the line pressure drops sufficiently to indicate that the relief valve has closed.
7 more elements
A cryopump comprising:
- at least first and second stages in a cryopump chamber cooled by a cryogenic refrigerator;
- at least first and second heating elements for heating the cryopump stages;
- a warm purge gas valve for applying purge gas to the cryopump chamber;
- a roughing valve for coupling the cryopump chamber to a roughing pump;
- a self-actuating relief valve for coupling the cryopump chamber to the roughing pump, the relief valve opening to the roughing pump at a first cryopump pressure level less than a predetermined maximum pressure and closing when the cryopump pressure drops below a second cryopump pressure level;
- a pressure sensor for monitoring pressure in a line between the relief valve and the roughing pump;
- and
- an electronic controller for controlling the heating elements, purge gas valve, and roughing valve, and for monitoring the pressure sensor, the controller being programmed to control a regeneration process by:
- warming the cryopump to release gases from the cryopump;
- monitoring pressure in a line between the relief valve and the roughing pump;
- opening the roughing valve to the roughing pump after the line pressure drops sufficiently to indicate that the relief valve has closed.
8 more elements
Dependencies are inferred from the claim text.