Service Tip - Air Filters
One of the leading causes of premature blower failure is a dirty inlet filter element.
Why? During normal operation, the filter element is removing dirt, dust, pollen
and other types of particles from the air stream. These particles collect on the
surface of the filter element. As they collect, they block a portion of the filter
media, thus reducing the amount of media available to pass the air molecules. The
result is an increase in the pressure drop through the element. Over time, the pressure
drop can become very high. This can lead to too high of a differential pressure,
too high of a differential temperature, or both.
High differential pressure increases the mechanical load on the blower. This can
cause a bearing failure or rotor contact. The results of a bearing failure are fairly
obvious. In the case of intermittent or short term rotor contact however, your blower
can lose efficiency, the effects of which may not be immediately apparent. You can
be sure however, that if the rotors wear from this condition, they cannot be repaired.
They must be replaced and that is very costly.
Too high a differential temperature can also cause a loss of efficiency. When a
blower runs too hot, the rotors can expand and make contact with bearing housings.
If this condition is not corrected quickly, a major failure will occur. While rotors
can be repaired if this occurs, the failure also involves damage to the bearing
housings, so repair may become uneconomical even if possible.
Service Tip - Lubrication
Bearings, seals and timing gears - the wearing parts - all need lubrication. Lack
of oil or grease causes nearly immediate failure. Most failures due to lack of lubricant
are operator preventable. The result can be a bearing failure, gear failure or both.
Unless this is caught immediately, there is usually rotor and endplate damage. This
is very expensive.
Improper Type and Grade of Oil quickly causes irreversible damage to seals, bearings
and gears. In the case of seals, they develop nearly microscopic cracks in the seal
face. Once the seals are damaged in this way, they leak until you replace the seals.
For each type of blower there are instructions in that blower's specific O&M manual
as to the kinds and grades of lubricants needed as well as the recommended oil change
or re-greasing intervals. Follow those instructions carefully. For Gardner Denver
blowers, we suggest that you use AEON PD oil. This synthetic lubricant has been
formulated specifically for this service. And it lasts four to six times as long
as standard mineral oils.
Always make sure to keep the oil sight glass clean and never overfill the gear case.
With too much oil, the action of the gears causes excessive foaming from entrained
air. This effectively reduces lubricity thus leading to premature wear and possibly
failure.
