A Discussion About Proactive Maintenance
with Gerry Trodd, Millar Western
Gerry Trodd, Millar Western
www.noria.com
Posted 5-16-05
In a world of fierce competition, individuality and unique
ideas bring fresh solutions to solving age-old industry issues.
Millar Western, a family owned pulp and paper mill, was able
to take rising economic prices and capitalize on market conditions
by further reducing scheduled maintenance using proactive
maintenance strategies.
Introduction
In 1988, Millar Western constructed its first chemi-thermal
mechanical pulp (CTMP) mill in Whitecourt, Alberta, Canada.
They completed a sister mill in 1992 at Meadow Lake, Saskatchewan,
Canada. Within the Whitecourt plant, there is a forest products
pulp division that uses two state-of-the-art CTMP facilities.
The sister mill at Meadow Lake was the first successful zero-effluent
pulp mill in the world. Both plants produce flash dried chemi-thermal
mechanical baled pulp used in such products as fine finishing
paper and opaque cereal bag liners.
From 1988-1994, the Whitecourt Plant had been successfully
practicing preventive maintenance. In 1995, management decided
to use increasing pulp prices as a catalyst to invest in the
company’s further growth. The preventive maintenance
program in place at that time consisted of two major shut
downs each year in addition to regular maintenance practices.
This prompted the mechanical maintenance group and management
to re-evaluate their current maintenance practices. They agreed
that the preventive maintenance program had been successful,
but a more aggressive program would help Millar Western remain
competitive in the long run. The group implemented a mill-wide
lifestyle change to push the limits of maintenance into a
new realm
of reliability.
Defining the Goals
Management and maintenance agreed to refocus their efforts
on condition monitoring activities during normal mill operation
to uncover those defects or deficiencies requiring action.
Management wanted to reduce downtime and increase production,
thus producing greater profits. Maintenance wanted to take
that one step further. They wanted to have empty storage shelves,
meaning they’re functioning proactively. They wanted
to routinely monitor the equipment so when testing shows something
awry, downtime can be scheduled and supplies ordered “just-in-time,”
before failure occurs.
They established six goals for their program (see sidebar).
These goals would be reached by implementing vibration analysis
and oil analysis.
Predictive Maintenance Program
The team started with vibration analysis, which proved to
be a challenge for them, from recording the data to learning
to interpret the results. Within two years, the team was able
to bring vibration analysis online and merge it into the computerized
maintenance management system (CMMS) they already had in place.
Once vibration analysis was up and running, the team focused
on implementing oil analysis at the mill. Basic oil testing
had been performed on larger, more expensive equipment since
the mill’s opening. Their lube oil supplier primarily
provided elemental spectrography. They also collect Direct
Reading (DR) and analytical ferrography readings when necessary.
In 1996, Millar Western purchased an onsite particle counter
along with oil analysis software. The software merged onsite
oil analysis data with the data generated by the outside laboratory.
And, the software interfaced with the existing CMMS software.
This software allowed them to manage the data collected by
the tests (regardless of where the sample was collected) and
integrate the data into the existing CMMS. Oil sampling routes
were consistent with already established vibration routes.
According to Mr. Trodd, oil analysis seemed to get in line
faster than the complex vibration analysis.
Once the software was in place, it became easier to expand
the program to other equipment. Eventually, the new program
encompassed all of the mill’s equipment. They drastically
reduced turn around test times on spectrography testing by
enabling an electronic data transfer of the data directly
into the onsite software program. They were also able to import
all historical DR and ferrography test data. Initially, ISO
codes were not a concern until the actual machine levels were
inspected.
Condition-based monitoring of their machines, which included
vibration analysis and “maintenance in a bottle,”
as the team refers to oil analysis, rather than turning wrenches,
has impacted all of the mill management goals. Keeping the
technologies simple at the grass roots level has not only
produced a “silent filter” phenomenon
but also has created the birth of the “invisible wrench.”
This means many more people take part in the program because
they know the results are important.
The development of the oil analysis program has been by far
the most proactive maintenance tool introduced at the plant
says Mr. Trodd. Millar Western’s qualified tradesmen
responsible for mill equipment have been involved since the
programs inception. Commitment and hard work have pushed Millar
Western to where they
are today.
Action is taken to find and eliminate the root cause of the
problem and, if possible, bring the lubricant back to an acceptable
operating condition. When high particle counts are detected,
area tradesmen use either portable filtration and/or an oil
change, depending on the circumstances. Additionally, they
can send the abnormal samples out for further testing. If
a problem with the oil’s condition is suspected, detailed
oil analysis including viscosity, total acid number, elemental
spectroscopy and sediment testing are conducted. If component
wear is suspect the sample is sent to a lab for ferrography
testing.
A survey of the 65 ground floor process pumps revealed ISO
cleanliness codes of 18/15 and higher. Also, high levels of
water were detected. The team scheduled multiple oil changes
in an attempt to eliminate the problem. However, particle
levels remained high and more than 50% of the pumps had excessive
water contamination.
Because multiple oil changes yielded little benefit, the
team decided to deploy portable off-line filtration. This
measure significantly reduced particle contamination levels.
The next group of samples on the pumps indicated that only
18% of the machines exceeded the ISO 17/14 target cleanliness
level. With the particle contamination problem under control,
the team had a clear direction in which to focus; seal-up
the power end units to reduce water contamination. Upon further
investigation, the team discovered that of the 18% non-conforming
results, only 3% were due to high particle count; 15% were
due to excessive water contamination. Currently the team is
testing a variety of pump sealing combinations to address
the water contamination issue on a mill-wide scale.
Once the ground floor was under control they moved through
the plant area-by-area cleaning up all the process gearboxes
in the same manner, all done during production. Millar Western
no longer utilizes any unscheduled down time for oil changes
on any of the pumps within the plant, and cleanliness targets
of ISO 16/13 are consistently met or exceeded. Throughout
the plant, the results are three times cleaner than when the
program was initially started. They discovered that once the
results reach an ISO code of 14/11 or 15/12 on a pump it normally
stays there for very long periods of time, which means the
chain of wear generation has been eliminated, or there is
“no wear” being generated once you reach a certain
level of cleanliness.
Hydraulic systems were one of the last machine groups brought
into the program. The filtration standards on new equipment
were good and component reliability had also been very good
since the mill’s startup. The oil analysis program proved
to be most beneficial to the plant in identifying key system
component failures, dramatically reducing maintenance costs.
The Results
Presently, Millar Western monitors 450 sample points, 300
of which are performed on a monthly basis. If a deviation
from an expected trend is reported, then area tradesmen immediately
take corrective action on the machine. Machinery availability
goals are set at greater than 97.5% so there is very little
room for error. For example, in the past if a large hydraulic
motor developed a shaft seal leak it was totally rebuilt at
an average cost of $21,000 per event. The goal is to run the
component until it starts to fail then pull it from service
for a total rebuild, maximizing its life cycle, pushing maintenance
costs to a point where it is justified to be spent on the
component.
Over the last five years their program has been exceeding
goals with staggering results, largely due to advancements
in the predictive maintenance program. In five years Millar
Western has reduced lubrication costs by 12% or $10,000. During
this time, they reduced solid grease consumption from 2000
kg to 1000 kg; and reduced liquid lubricant consumption from
57,000 liters in 1997 to 32,000 liters in 1999 (beating their
goal by 2,000 liters).
Perhaps the most significant result of the program is the
new level of ownership the tradesman take in achieving machine
reliability. They take pride in their work and feel responsible
for the equipment. The level of commitment and satisfaction
the tradesman have for their job has also had a profound impact
on reducing absenteeism.
“Everyday we push the parameters of the program. It
sounds scary, but with over 300 years maintenance experience
within the group, failures are rare. “Over the last
5 years it has been a treat to be involved with such a group
of professionals committed to the predictive maintenance technologies
discussed and their continued improvement, plus their mindset
on not accepting the ‘norm’ as being acceptable
within today’s business of maintenance,” concluded
Mr. Trodd.
|