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Maintenance and Inspection - Blower
September 8, 2003
Introduction
The manufacturer’s
maintenance procedures and recommendations should be reviewed and strictly adhered to in
order to ensure the proper operation of the equipment.
The following is provided as a general guideline only.
Maintenance and Inspection Schedule
| Shift |
- Check and record vibration and temperature readings.
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| Daily |
- Check oil level in reservoir.
- Check pressure drop across the oil filter. Switch to
spare filter and replace dirty filter.
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| Weekly |
- Check condition of oil. Ensure that there is no water in
the oil.
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| Monthly |
- Measure and record machine noise levels
- Check oil filter and clean or replace as required.
- Check gear box oil seals for leaks.
- Clean gear box vent filter.
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| Shutdown |
Every
year, the following should be done during the shutdown:
- Completely drain oil from the system. Purify and
centrifuge the oil. Examine all oil-bearing components
- Inspect gear teeth of the gear box.
- Check for misalignment of the gear box housing.
Every two (2)
years, the following should be done during the shutdown:
- Inspect gaps and bearing clearances
- Inspect alignment.
- Perform a thorough inspection of the machine including,
impeller, bearings, shaft seals, coupling, etc.
- Perform a major overhaul of the gear box.
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Impeller Washing
During normal operation deposits may form on the impeller and
in the area between the back of the impeller and the scroll housing. These deposits
may lead to high vibrations in the compressor leading to a blower and plant shutdown.
This problem generally occurs as a result of poor mist elimination at the top of
the drying tower.
When an imbalance occurs due to deposits forming on the
impeller, the blower must be shutdown and the impeller and casing washed to remove the
deposits.
Shutdowns
There may be times when the blower is not operated for
extended periods of time such as during the annual plant shutdown. To prevent damage
to the blower the following actions must be taken:
- To prevent corrosion to the bearings, the lubrication system
should be flushed with oil once a week for 30 minutes. This can be done by switching
on the electric motor driven auxiliary lube oil pump.
- Cooling water lines should be protected from freezing when
ambient temperatures are low.
- The inlet guide vanes should be actuated over its entire
range.
Lubrication System
The manufacturer’s recommended oil must be used for the
compressor. Under no circumstances may anti-foaming additives (molybdenum disulphide
and/or high pressure additives) be added later. The use of lubrication oils other
than the manufacturer’s recommended oil may void any warranties on the machine.
All attempts must be made to avoid getting dust, dirt, scale,
fibres, etc. in to the lubrication oil and system. Use lint-free cloths for
cleaning.
Any new lube oil piping must be pickled prior to installation
to ensure the insides are free of scale and dirt.
Any new oil added to the system to make-up for losses must be
of the same quality used in the machine. Oil must never be added directly to the
reservoir but must be poured through a fine-mesh screen. Records should be kept of
the oil type, manufacturer, quantity added, filling dates, etc.
Electric Motor
Maintenance of the electric motor will depend on the duty
that the motor has been subjected to including the ambient temperature, stopping and
starting frequency, atmospheric air quality, etc. Maintenance on the motor will
include such activities as:
- Measurement of insulation resistance to determine the quality
of the insulation.
- Cleaning of the motor interior to remove dust, dirt, oil, etc.
- Cleaning and replacement of air filters (if equipped)
- Inspection of bearings
Problems
| Impeller Corrosion/Erosion Corrosion or erosion of a blower impeller can occur when there is excessive
carry over of acid mist/droplets from the outlet of a drying tower due to poor mist
eliminator performance or acid distribution problems. Deposits may form on the
blades resulting in high vibrations and reduced bearing life. Impellers should be
inspected during each plant turnaround and more often if excessive vibrations are
observed.
Washing the impeller on a regular basis will remove the
buildup of solids that lead to high vibrations but the cause of the deposits should be
fixed to prevent further buildup.
The performance and condition of the drying tower mist
eliminators should be monitored. The easiest way to monitor their performance is to
do regular stick tests at the exit of
the tower.
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