Ulvac CRYO-U Series Instruction Manual page 59

CRYO-U Cryopump Instruction Manual
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◇ Assisted warm-up using inert gas
This is a heating method of which introduces inert gas (nitrogen that its dew point temperature is
－40℃ or below or argon) immediately after the cryopump has been stopped and make the
temperature of the 80K shield, 80K baffle, and 15K cryopanel rise to room temperature. This
enables more efficient regeneration compared to an unassisted warm-up in the following respects.
Shortens the time period to warm up the 80K shield, 80K baffle, and 15K
・
cryopanel to room temperature.
Shortens the time period to check the pressure buildup, as the inert gas will
・
reduce the amount of water adsorbed onto 15K cryopanel.
◇ Assisted warm-up using a heater
In addition to the method using inert gas described above, using an optional band heater or inner
heater enables warm up time even shorter. (The band heater or inner heater is not applicable for
certain types of cryopump.)
ULVAC CRYOGENICS INC. offers different types of standard band heaters such as RBH type
and silicon rubber type. The RBH band heaters self control the temperature around 70 ～ 80℃.
The silicon rubber heater turns its power ON/OFF by its thermostat setting. Please refer to the
instruction manual of each heater that you use for more information.
When using an inner heater, make sure to control the temperature with our CRYO Heater
Controller (optional) such as MBDI-H1 series. The warm-up completion temperature should be
set at 300K both at the 1st and the 2nd stages. Refer to the controller instruction manual for
more details.
Maximum allowable temperature of the refrigerator unit is 70℃. If you use a heater, make sure to
control the heater temperature so that the temperature of the cold stages of the refrigerator does not
exceed 70℃. If it exceeds 70℃, inside of the refrigerator may be damaged by the heat and a
refrigerator replacement may be needed.
Our standard band heaters are self temperature control type so they can be used without any
temperature control instrument. However, when using a heater other than our standard band heater,
make sure to have a measure to keep the temperature lower than 70℃ such as having a
temperature controller, overheat alarm function, or by observing and controlling the energizing time.
Since the temperature of the heater surface becomes very high, make sure to take necessary
measures to prevent fire and burn injury and also display warnings to call attention for safety.
CAUTION
WARNING
ULVAC CRYOGENICS INCORPORATED 6-3