PUMPS AND PIPELINES
“Monitoring the performance characteristics of
the pump regularly keeps you informed of its
operation and provides ample time to take a
measured response rather than incurring a
failure and unplanned downtime,” Weir says
Ready to flow
In a sector often viewed as stationary when it comes to
technology development, pump manufacturers are now
adapting to the increasingly complex tasks being asked
of them by mining companies. Dan Gleeson explores a
market ready to evolve
umps are continually being asked more of
from the mining sector as minerals
processing complexity increases and
operators delve deeper below ground to extract
ore.
Those manufacturing the pumps and
pipelines that keep product, tailings and water
moving are also doing so against a changing
environmental backdrop.
Not only are they being asked to use less
water and recycle any they do use, they are also
required to carry out tasks through more
environmentally friendly means; using diesel-
powered engine alternatives and oils and
lubricants that come with low-carbon footprints.
P
Staying regular
Weir has established brands in the mining
pumps sector, with Geho ® and Warman ® in the
slurry moving field and Multiflo ® in the
dewatering space.
The company is a true believer in regular
maintenance for slurry pumps, arguing it
“extends the wear life, helps avoid unplanned
downtime and lowers the total ownership cost
for end users”.
Its confidence in this philosophy is backed up
with significant digitalisation investments.
For example, its IIoT Synertrex ® platform
allows operators to closely monitor the health
and performance of their pumps and triggers an
alert when an issue occurs. When installed on a
Warman ® pump, Synertrex ® can monitor the
bearings and gland seal health, detect
cavitation and other hydraulic anomalies, track
efficiency and forecast wear life, allowing
operators to make condition-based decisions,
Weir said.
It is through such initiatives it can say with
some certainly that running slurry pumps to
breaking point could in the long term be “doing
your plant an injustice”.
“Monitoring the performance characteristics
of the pump regularly keeps you informed of its
operation and provides ample time to take a
measured response rather than incurring a
failure and unplanned downtime,” Weir said.
And, from a preventative perspective, there
are regular tasks to carry out during these
intervals to ensure a pump runs for longer.
Vibration is a key and early indicator of a
pump’s health, according to Weir. “The vibration
velocity target varies from pump to pump,” the
company said, adding that the maximum value
target for a large pump will be greater than a
medium-sized pump handling water.
“Conversely, when we introduce solids into
the fluid, the vibration will increase in relation
to the mixture properties and the duty
parameters,” Weir said. “When running routine
inspections, we always refer to historical data to
understand the range of vibration acceptable for
that particular pump in that particular
application.”
Vibration monitoring is about following a
trend on a regular basis to understand if there
has been a noticeable change, according to
Weir.
“Once the pump reaches the end of its wear
life, it’s normal to experience an exponential
growth curve in vibration readings, which will
start to increase gradually,” Weir said.
“However, if our team notices a spike in
vibration before the end of its service life, then
we know something is wrong and requires
further investigation.”
When it comes to a pump’s bearing assembly,
the service life of this component is heavily
dependent on the process and operation,
according to Weir. One of the main contributors
to premature bearing failure is inadequate gland
seal maintenance, which can cause leakage,
spraying slurry and water directly onto the
bearing assembly. This can be minimised by
regularly adjusting the seal and applying correct
and consistent lubrication, Weir said.
“Throatbush wear rate has a major impact on
the overall efficiency of slurry pumps and in
many applications has the shortest life
compared to other components,” Weir said.
Weir’s team can spend an hour on each pump
adjusting and fine tuning the throatbush to
extend the life of the pump by up to 50%,
bringing it in line with the lifetime of other
components. “This [enables]…the operator to
derive the maximum value in terms of cost per
tonne from the overall rebuild cost,” Weir said.
The importance of adjusting the throatbush
to ensure the optimum gap between the
impeller is also vital, Weir said. “To help
improve this process for operators, we
developed automated rotating and axial
adjustment technology, speeding up the
process and increasing the accuracy of axial
movement.”
Weir’s maintenance investigations don’t stop
there. “A drop in efficiency is not always an
issue with the pump,” the company noted. “We
need to analyse the operating parameters and
evaluate the application to identify the root
cause.”
This is where its specialists are able to
inspect upstream and downstream of the pump
to understand if there is anything affecting the
pump’s operation.
Integrating expertise
It is a similar holistic approach that has allowed
Metso’s pumps business to make serious
inroads into the mining pumps and pipelines
sector, with the company able to integrate
several solutions to produce the most productive
and cost-effective mineral processing operation.
The company used the recent Bauma fair to
showcase several new solutions, including its
MDR500 pump for mill discharge applications.
JUNE 2019 | International Mining 67