|
Eastman Chemical Company started its
Motor Analysis Program in late 1998 when we purchased an online power
analyzer. After several months of testing, we found the analyzer to be
limited for rotor/stator testing at our plant, due to the low-level
loads on many of our motors. The power quality testing was also
limited at our facility because we produce most of our own utilities
and our power quality is very good.
Therefore, in 1999 we started pursuing
other options for condition monitoring of motors. We set up three
motors with controlled conditions: shorted wires in turn, offset rotor
0.01”, shorted stator core steel, and an open rotor bar. A PdMA
representative was brought in to test these motors offline. All
conditions were correctly identified, and a decision was made to
purchase the PdMA MCEMAX analyzer. We have been using the analyzer for
approximately two years now, and are very pleased with the results.
Although most of the analyzers are advertised as rotor bar analysis
tools, this article discusses some of the areas into which we have
expanded the use of this technology at our plant.
|
|
|
| Figure 1: Gasification
process rod mill, 800 HP motor, clutch and gearbox. |
Figure 2: Rod mill pinion
shaft failure |
|
|
ROD MILL CLUTCH ENGAGEMENT
Rod mills are used to crush the coal
used in our gasification process. The pinion gear transmits motor
torque through the gear reducer to the rod mill’s gear reducer
(Figure 1). The motor is connected to the gearbox through a clutch,
which uses an inert gas to engage the clutch disk. The clutch in turn
is coupled to the gearbox, which in turn is coupled to the rod mill.
The pinion’s design life is five years minimum. Between 1997 and
1998, five pinions failed (Figure 2) between the two rod mills in our
gasification process.
Next Page
> Page 1/2/3/4/5/6
|
