| 摘要 |
A vacuum device comprises a plurality of cryopumps ( 10 ), particularly a plurality of cryopumps connected in parallel. Further, at least one compressor device ( 16 ) is provided which is connected to the cryopumps ( 10 ) via medium supply conduits ( 12 ). A medium return conduit ( 14 ) is also connected to the compressor device ( 16 ) and the cryopumps ( 10 ). Arranged between the medium supply conduit ( 12 ) and the medium return conduit ( 14 ) is a storage container ( 20 ) for medium. Further, a pressure measurement device ( 30 ) is provided in the medium supply conduit ( 12 ). The pressure measurement device ( 30 ) is connected, via a control unit ( 32 ), to a supply valve ( 26 ). To keep the pressure difference at the cryopumps ( 10 ) as constant as possible, the supply valve ( 26 ) is opened when a threshold value of the pressure in the medium supply conduit ( 12 ) is exceeded, thus causing medium to flow into the storage container ( 20 ). |
