Patent ID: 11885321
Assignee: SUMITOMO HEAVY INDUSTRIES, LTD.
Field: Chemical engineering (Chemistry)
Classification: CPC F  B | IPC F

Claim 10:
11. A cryopump comprising:
a cryopump housing;
a cryopanel disposed in the cryopump housing and provided with a non-combustible adsorbent;
a heater that heats the non-combustible adsorbent and the cryopanel;
a purge valve that is mounted to the cryopump housing and connects the cryopump housing to a purge gas source;
a rough valve that is mounted to the cryopump housing and connects the cryopump housing to a rough pump;
a sensor that generates a measurement signal indicating a temperature of the non-combustible adsorbent or an internal pressure of the cryopump housing; and
a controller that receives a regeneration start command and controls at least one of the heater, the purge valve, and the rough valve based on the measurement signal so as to execute either (i) a sublimation regeneration sequence or (ii) a dehydration sequence,
the sublimation regeneration sequence configured to sublimate water from the non-combustible adsorbent by exposing the non-combustible adsorbent to a vacuum atmosphere,
the dehydration sequence configured to dehydrate the non-combustible adsorbent by exposing the non-combustible adsorbent to a dry atmosphere having a higher pressure than the vacuum atmosphere, at room temperature or a temperature higher than the room temperature,
wherein the controller is configured to control at least one of the heater, the purge valve, and the rough valve to execute an additional dehydration sequence following the dehydration sequence, and
the additional dehydration sequence is configured to reduce water remaining in the non-combustible adsorbent by evacuation of the cryopump housing through the rough valve, or by rough-and-purge in which the evacuation and supply of a purge gas to the cryopump housing through the purge valve are alternately repeated.