Ulvac CRYO-U Series, Instruction Manual

Page: 60 / 106

Regeneration
6.4 Regeneration Flow Chart
The following flow chart explains each
regeneration method when using the unassisted
warm-up and the assisted warm-up. The
procedures described here are based on the
CRYO-U
®
Cryopump Vacuum System shown in Figure
4-1.
◇
Regeneration through unassisted warm-up
Ⅰ．
Warm-up
Close the main valve (V1), then shut off the
cryopump. The unassisted warm-up starts.
Ⅱ．
Discharge (desorption) of captured gas
Leave as it is until 80K shield, 80K baffle, and
15K cryopanel reach room temperature for
exhausting the gas.
Ⅲ．
Pressure buildup check
Open the roughing valve (RV1) and rough pump
the cryopump to 40Pa.
Then close the roughing valve (RV1) and check
the buildup of pressure in the cryopump. If the
pressure buildup value stayed less than 6.5Pa
for five minutes, the check is completed.
If it increased 6.5Pa or more in five minutes,
repeat the rough pumping procedures to 40 Pa
and the pressure buildup check.
Ⅳ．
Cool down
Open the roughing valve after the pressure
buildup check. Then rough pump the cryopump
to 40Pa.
After closing the roughing valve (RV1), start the
cryopump. When the cryopump is cooled down
to the prescribed temperature, the regeneration
process is completed
No
Yes
No
Start up regeneration
Ⅰ
Close main valve (V1)
Shut off cryopump
Ⅱ
80K shield, 80K baffle,15K cryopanel
warming up to room temperature
Ⅲ
Press. buildup check
completed
Open roughing valve (RV1)
Rough pump cryopump to 40Pa
Close roughing valve (RV1)
Yes
Regeneration completed
Ⅳ
No
Yes
Open roughing valve (RV1)
Pressure
≨
40Pa
Close roughing valve (RV1)
No
Yes
Cool down completed
Start up cryopump
6-4 ULVAC CRYOGENICS INCORPORATED