Improve Equipment Reliability and Reduce Costs with Clean Oil
By Caren Caffrey
While many companies struggle to contain costs and reduce their environmental footprint, quite a few underestimate
the value found in keeping oil clean and
dry. Oil is traditionally changed at recommended time intervals rather than
when the key features of the lubricant,
such as AW and EP additives, no longer
function. Removing or reducing the primary contaminants responsible for additive consumption and oil degradation
will extend the life of the lubricant and
the equipment it is designed to protect.
Most oil problems can be attributed
to the following types of contaminants:
• Particulates like dirt and wear metals
generate abrasive wear and cause
machine breakdowns.
• Moisture/water from condensate or
process conditions creates micropit
ting and cavitation, which lead to
spalling and fatigue wear.
• Oxidation products like varnish and
sludge lead to “sticking” valves and
dirty vessels.
In a medium-loaded oil system,
research shows that about 70%-80% of
the particulates are below 5 microns
(µm) and almost 90% of the particulates are below 10 µm in size. If the
mechanical system in question has a
clearance zone that is less than 10 µm,
these particles get caught in the boundary zone and are slowly ground down
until they are small enough to pass
through the metal cracks. Elimination of these small particles through
effective filtration improves machine
productivity exponentially.
In the real world, maintenance
teams must balance proactive preventative maintenance opportunities against
the constant demands of production
and cost of downtime. For large mobile
equipment such as a haul truck, the
costs of repairing a wheel motor can be
enormous, easily exceeding $250,000
per day. If needed parts are not readily
available, these costs can quickly skyrocket into the millions.
• Lost production: $190,000 + per day
• Oil change: $3,500-$15,000
• Minor repair (seal replacement):
$90,00-$130,000
• Major repair (seals, bearings, sleeves):
$230,000-$260,000
• Wheel motor replacement:
$650,000-$780,000 (Lead time:
1-21 days)
Proactively cleaning key lubricant
systems rather than simply changing oil
at predetermined time intervals will
reduce maintenance costs and maximize equipment productivity. The CJC
Mobile Flushing Unit was specifically
designed to handle the highly viscous
gear oils with the very low temperatures
found in the mining industry.
Field tests have proven the CJC
Mobile Flushing Unit will quickly clean
lubricants from ISO VG 32 to ISO 680+
during routine PM service intervals.
Clean oil from the heated reservoir is
pumped at approximately 3.5 gpm
(800 l/hr) through the gearbox (rear differential, planetary, etc.) pushing contaminated oil back through the cellulose depth filters. The 3 µm CJC MFU
Filter Inserts capture approximately 50-60 lb of particulates, dirt and varnish
while adsorbing residual water. Oil
cleanliness is continuously measured
with the online CJC Oil Contamination
Monitor. This unit is versatile enough to
work in the confines of a shop or the
harsh environments found in the most
rugged job sites.
The CJC Mobile Flushing Unit has
been tested in some of the harshest
climates. In one example, Mobile SHC
680 gear oil from a 320-ton Komatsu
930E haul truck was flushed in the
field at below freezing temperatures
(-4ºC). Within 90 minutes, the contaminant level was reduced from
ISO 25/25/23 (>16 million particles
at 4 µm) down to an ISO 16/15/11
(<64,000 particles at 4µm). Based on
the following Life Extension Table published by Noria Corp., this
will essentially extend the life of the
lubricant and equipment by 3.5 times.
When another operation went to fill
a new Cat 7495 shovel with oil, they
realized the new oil at ISO 23/19/14
was eight times dirtier than the OEM
requirement of ISO 19/17/14. Thus,
they could not transfer oil to the shovel
until it had been cleaned without voiding the warranty. After several attempts
to clean and transfer the oil through
the on-board filters, a CJC Mobile
Flushing Unit was brought in. Each
200-l (52-gal) batch of oil was cleaned
to ISO 14/13/11 within 30 minutes and
then transferred to the shovel. By prefiltering the oil with the CJC Mobile
Flushing Unit, the company was able to
complete the fill process within a week
rather than a month as expected.
One maintenance group implemented “mini-PM” sessions on Cat 793 haul
trucks every 500 hours. Using the CJC
Mobile Flushing Unit, they reduced the
oil contamination level from an average
ISO 22/20/17 (2 million-4 million particles at 4µm) to ISO 17/15/12
(<130,000 particles at 4µm) within the
allotted 8 hour PM time frame. Flushing
the oil allowed the company to extend
oil change intervals from 18,000 hours
to 25,000 hours. Using historic operating rates and wheel rebuild intervals,
this group predicted that they will save
approximately $380,000 on wheel
rebuild costs and another $100,000 on
reduced oil consumption, labor and
downtime annually.
The CJC Mobile Flushing Unit
removed 98% of the particulate contaminants from the SAE 60 Final Drive
Axle Oil in the planetary/differential
gear system on a Cat 797B haul truck
within 5 hours. This business unit traditionally changed the oil <2,000 hours
at a cost of approximately $15,000 per
vehicle. By reducing the particulate
contamination from ISO 22/20/15 (2
million-4 million particles at 4µm) to
ISO 16/15/12 (<64,000 particles at
4µm), they expect to achieve a life
extension on the oil and equipment by
2.5 times. Based on the fleet size,
eliminating one or two oil changes per
year on each vehicle will generate savings of aproximately $1.5-$3 million,
respectively.
These case studies illustrate the
value obtained from reducing oil contaminant levels in heavy machinery
with the CJC Mobile Flushing Unit. In
addition to having a larger dirt holding
capacity than most filter elements, the
proprietary cellulose inserts are made
from a renewable, sustainable resource
that can be disposed of in a green
manner. Declining oil consumption
and the elimination of metal filter canisters from landfills will ultimately
reduce the organization’s environmental footprint. Caffrey is an account manager–mining
with C.C.Jensen Inc. This article was
adapted from a paper she presented at
the Haulage & Loading 2013 conference, which took place during May in
Phoenix, Arizona, USA.
The CJC Mobile Flushing Unit pumps oil even at very low temperatures.
The CJC unit has high contaminant handling capacity.
As featured in Womp 2013 Vol 08 - www.womp-int.com