Operating manual liquid ring vacuum pumps and compressors series TRH - TRS - TRM - TRV - SA & Systems type HYDROSYS - OILSYS
29
ITEM 1B, then partially open flow regulating valve ITEM 13 between the discharge of circulating pump ITEM 22 and the
heat exchanger ITEM 9 and the by-pass valve ITEM 13A.
If the system is fitted with a separator cyclone ITEM 1D and the adjacent collecting tank ITEM 1E, it is required to close
valves ITEM 11A and 12 and open valve ITEM 13E.
Fill frame separator with service oil through the filling plug ITEM 28. Proper oil level can be seen on sight glass ITEM 7.
Refer to tab. 11 and 12 for the required oil quantity.
Start and/or open applicable accessories (temperature switches, level switches, etc.) and circuitry for cooling and
flushing.
Start vacuum pump ITEM 4 and soon after start the circulating pump ITEM 22. Adjust the circulating pump capacity with
valve ITEM 13.
Gradually open the system suction valve till the desired vacuum is achieved. Check the systems for abnormal noises or
vibrations (see chapters 12 and 16).
Adjust by-pass valve ITEM 13A to regulate the oil flow to the vacuum pump or to improve the thermodynamic efficiency
of the heat exchanger.
NOTE:
OILSYS systems engineered with multiple pumps are fitted with isolating valves at suction, discharge, and
service liquid lines of each pump. When one or more pumps are not operating it is required to isolate the idle
pump(s) by closing these valves. When the pumps are put back into service the said valves (at suction and
discharge) must be opened.
11.5 -
OPERATION OF “OILSYS” SYSTEMS
After starting the vacuum pump check the following:
- the vacuum level is as desired or adjust the flow regulating valve to the required vacuum
- the oil temperature is between 60 and 80°C. If required, adjust the thermostat on the radiator or in case of water/oil
heat exchanger adjust the cooling water flow
- motor does not draw more amperage than shown on its nameplate
- the pump-motor assembly does not have abnormal vibrations or noises such as cavitation
- the frame temperature at full load, does not exceed approximately 85°C
- that there are no leaks from mechanical seals, joints, flushing or cooling liquid lines
- liquid level in separator and frame is between the minimum and the maximum
- the pressure gauge of the oil demister separator does not read more than 0,3 bar. When this value is exceeded it will
be required to change the filter element.
If the gas discharge is not open to the immediate atmosphere but it is piped to other locations, the pump discharge
should be checked for back-pressures that could cause higher power consumption and loss of pump capacity
.
11.6 -
SHUT DOWN OF “OILSYS” SYSTEMS
Close, if applicable, the cooling water to the water/oil heat exchanger ITEM 9, then turn off the power to the circulating
pump ITEM 22.
Where possible, gradually decrease the vacuum level to 400/900 mbar in about 10 seconds max. The discharged
service liquid from pump ITEM 4 helps producing a slow deceleration rather than sadden stop.
Turn off motor ITEM 6, radiator ITEM 9 and any accessories and flushing circuitry.
Make sure the non return valves ITEM 2, or similar, at suction and discharge lines are leak tight
.
Should the system be idle for an extended period of time it is recommended to disconnect the electricity to the motor
panel, drain all liquids from pump, separator and piping. Refer to chapter 6 for storage procedures
.
12 - OPERATING MAINTENANCE
Periodically check the working conditions of the system by means of the instrumentation on the installation (pressure
gauges, vacuum gauges, temperature gauges, ampmeters, etc.) and if the pump is consistently handling the application
for which it was selected.
The operation of the pump should be without abnormal vibrations or noises, if any of these problems is noticed, the
pump should be stopped immediately, search for the cause and make the necessary corrections.
It is good practice to check the pump/motor alignment, the running conditions of the bearings and of the mechanical
seals (see chapter 13) at least once a year, even if no abnormalities have been noticed.
If there is a deterioration of the pump performance, which is not attributable to changes in system demands, the pump
must be stopped and proceed with necessary repairs or replacement.
If the mechanical seals are fitted with external flushing and/or quenching lines their pressures, temperatures and flows
must be checked constantly.
If during operation the pump seems to run irregularly, because of noise or vibrations, it is necessary to stop
the unit and investigate the causes of the malfunctioning (see chapter 18).
NEVER ALLOW THE PUMP TO OPERATE IN THE CAVITATION AREA!
Cavitation has the characteristic metallic sound, like if gravel was rotating inside the pump, and it causes also high
pump vibrations. This happens when the pump is running at absolute pressures close to the vapour tension of the
service liquid at the running conditions.
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