Pfeiffer Vacuum HISCROLL 12, Руководство по эксплуатации

Страница: 49 / 84

WARNING
Risk of poisoning from incorrect use of the gas ballast system
The gas ballast system of the scroll pump is vacuum sealed only when used in valid, snapped posi-
tions "0", "1" and "2". When operating the valves in intermediate stages, there is a risk that process
media can escape to the environment uncontrolled. When using toxic process media, there is a risk
of poisoning.
► Change the positions of the valve only for setting the gas ballast stages.
► Operate the gas ballast valve only in the snap positions.
NOTICE
Risk of damage from condensation in vacuum pump
Exceeding the saturation vapor pressure of process media during the compression phase leads to
condensation in the suction chamber. This results in an increase of the achievable ultimate pressure
and to a general deterioration of the performance data of the vacuum pump as a whole. Corrosion
and contamination impair service life.
► Use the gas ballast.
► Supply dry room air or inert gas in order to increase the vapor capacity of the process medium.
► Pump condensable vapors only when the vacuum pump is warm and the gas ballast valve open.
► Operate the vacuum pump with gas ballast a further approx. 30 minutes after finishing the proc-
ess in order to dissipate any residual moisture.
Gas flow
The flow rate (gas flow) increases according to inlet pressure.
Depending on the pump version, the vacuum pump has a mechanically operated two-stage gas ballast
valve for controlled supply of inert gas to the suction chamber.
Prerequisites
● Vacuum pump is warm
● An external gas supply is connected
● The inlet area of the gas ballast valve is flushed with inert gas in the ATEX version
Operating with gas ballast
1. If necessary, connect an existing shut-off unit to the vacuum side.
2. Turn the selector switch of the gas ballast valve to the desired position.
– Allow the selector switch to completely engage in position.
3. In case an external gas supply is used, open the supply.
– Observe the permissible inlet pressure.
G
A
S-
B
A
LLA
S
T
Position ″0″:
● Switch setting for media without condensation
● The gas ballast valve is closed
● No gas flow into the suction chamber
GA
S-
B
A
LLA
ST
Position ″1″:
● Switch setting for slight to medium condensation
● The gas ballast valve is open
● The gas flow depends on the type
GA
S
-
B
A
LLA
S
T
Position ″2″:
● Switch setting for medium to severe condensation
● The gas ballast valve is open
● The gas flow depends on the type
Tbl. 17: HiScroll gas ballast valve switch settings
Operation
49/84