How to unlock productivity savings in mining operations part 3 final_11.06.2017

How to Unlock Productivity
Savings in Mining
Operations
Part Three in a Series:
“Proven Disruptive Technology Solutions”
- Idler Rolls that last longer
- An innovative Cradle Assembly dramatically reduces time spent on roll
replacement activities
Both of the above realise millions of dollars from productivity gains
Report By: David Mallinson 11/06/2017
Part 3
Proven Disruptive
Technology Solutions

How to Unlock Productivity Savings in Mining
Operations
Part Three: “Proven Disruptive Technology Solutions”
Executive Summary
- Two solutions:
o Rolls that last longer
o An innovative Conveyor Idler Assembly (CIA) dramatically reduces time spent on
roll replacement activities
o Both the above realise millions of dollars in productivity improvements
- Other benefits
o OH&S risks mitigated
Overview – DunnEasy International Pty Ltd
Our idler roll heads and conveyor idler assembly with cassettes were invented and patented by
Les Dunn who is one of Australia’s leading mining technologists specializing in conveyor systems
for over 40 years.
The heads are inserted into either Fused Ferric (modified) stainless steel or high grade carbon
(black) steel idler shells. The stub axle (shaft) sits into low-grade heavy mass mount plates to
absorb vibrations in the cassettes in order to reduce the likelihood of damage to associated
infrastructure. Both the heads and assemblies are patented items worldwide.
The Fused Ferric (Modified) stainless steel rolls are produced by a unique spiral wrap tubular
shell Technology thereby eliminating MIS / TIR to as low as practically achievable.1
As proven by testing at Newcastle University2
ours is the only roll in any market that does not
allow dust and moisture into the bearing cage in the heads in their submerged testing regimen.
The latter is one of the primary causes of most rapid roll failures.
Our rolls have proven to last at least 5 times longer than any other similar priced roll in the
market place but in most instances have been found to last 5->10 times longer. The Fused Ferric
stainless steel or High grade >350mpa carbon (black steel) fabrication of our idler rolls is
arguably the highest quality available in the industry today. Both the heads and cassettes are
patented items worldwide.
Ours are ‘shaftless’ rolls which are very uncommon. The shell tubing replaces and acts for the
through-shaft without the additional mass of a solid or hollow through axle shaft as typical of
conventional idler rolls. This makes the rolls much lighter, utilising far less in energy to fabricate &
operate – meaning a minimal carbon footprint.
1 Our Fused Ferric is based on a proprietary modified SS-410L
2 TUNRA Bulk Solids Handling Research Associates Report #8551April 2015
1

Our rolls are manufactured to suit either replacement and/or brand new conveyor belts. They are
suited to be retrofitted any known conveyor belt system worldwide.
In most cases, when a roll needs replacing, the process requires 2-3 labour units, a mobile crane and
2-4 hours of conveyor belt shut down time. When our rolls are used in conjunction with our Conveyor
Idler Assembly using Cassette/s, change-out requires 1 labour unit & 8-10mins change out and no
belt shut down3
. Annually these productivity improvements equate to tens of millions of dollars per
location.
On almost all conveyors, at least 10% of rolls are failing requiring being changed out every year. In
many instances some parts of the conveyors have rolls changed every week. Some last <48 hours.
Solution 1
Rolls that last longer
To do this the rolls must be designed to:
- Have reduced bearing failure – the key cause of roll replacement
- Feature significantly improved TIR4
and MIS5
readings. These are to do with the roundness
of the pipe outer shell. It is essential to ensure pipe roundness to maximise efficiency and
reduce risk of shell failure and belt damage.
- Feature reduced Rim Drag6
- Be made of tougher material
- Weigh much less
- Avoid shell to end weld failure
3 Risk Assessment SAFETY Protocols to be site enacted
4
TIR is a measurement of the gross out of radius dimension of an idler. It measures ovality and bending of the shell tube. It also checks
whether the heads have been inserted squarely or have deviated from true, due to welding processes. It is measured by turning an idler on
its axis and measuring the surface position on a dial gauge of several points along the idler. The furthest reading is subtracted from the
closest.
5
MIS is a measurement of the maximum instantaneous slope of the pipe shell. MIS is measured by taking an accurate reading around the
diameter of the pipe every 6 degrees of rotation and comparing each reading to its adjacent readings. This indicates the slope of change of
roundness, ovality or denting of the shell tube. This type of measurement is repeated at three locations along the roller. It has been found to
directly correlate to the noisiness of the idler’s interaction with the belt above it. As noise is generated by a vibratory force, any noise is
placing more stress on the bearings and associated structural componentry.
6
Rim drag is the amount of force needed to turn an idler in Newtons. Lower rim drag, means a lower power bill.
2

Reduced bearing Failure
Problem Solution
Premature bearing failures. These fit into a
number of categories:
Contamination.
This occurs when foreign material enters the
bearing. It may be dirt, dust or water causing
corrosion. All bearing housings are fitted with
seals to prevent this. They are generally fitted to
either side of the bearing.
However fluctuations in temperature between
the inside area of the roll shell and the outside
ambient temperature of the roll, applies positive
or negative pressure forces which is sufficient to
overcome the integrity of the seal construction
allowing the ingress of externally built up
contaminant transiting past the seals in a screw
action similar to a car wheel bearings when
travelling through knee deep water.
Ours is a unique design. The bearing is fully
encapsulated in a minimal cavity void.
Being completely embedded in the head end
disc means that any small cavity volume
thermal pressure force differential (positive or
negative) cannot overcome the bearing’s single
outer lubricant contact lip. The latter also
features non-contact dust seals with a natural
design capability to allow the debris, dust,
moisture to wind through. All the seals are on
the shaft extension outer side. As a result
debris, dirt and moisture have great difficulty
entering the cavity confines. In addition the
radial ‘flinging’ action of the components makes
it almost impossible for any dissipated debris
and moisture to get to the lubricant seal.
Our proprietary external 304 grade S/S shield,
ABS Debris Shield and felt self-generating
micro-seal protects the single outer bearing
side. The inner race side is exposed to the very
minimal cavity volume and no sealing is
required on this side of the bearing. Having
such a small volume dramatically reduces the
normal pressuring forces that can move grease
out and contaminants into the bearing.
A 304 Grade stainless steel weather shield on
the outer side of the bearing is the only seal. It
repels all wash-down forces which are
dissipated through the self-generating felt
micro-seal to prevent any corrosive build up. A
felt debris seal is used – this in turn creates its
own non-contact micro-seal.
Problem Solution
Lubricant Failure.
Lubricant failure can be caused by a loss of
grease from mechanical forces or over heating
of the grease.
Our design incorporates minimum volume
encasement of the bearing cavity. This means
that when under centrifugal pressure, the grease
has nowhere to go and must stay in the housing.
The lubricant is a very high quality specially
formulated for the task of operations below -
300
C to >1300
C.
3

Problem Solution
Misalignment.
A bearing that is not mounted truly at right angles
to its rotating forces can develop premature wear
points.
Our bearing housings are CNC “Profiled’
machined using high tolerance tungsten tooling
as are the internal ends of the pipe shell.
The shell tubing is held as close as possible to
a perfect circular condition during ‘Profiling’ The
internal tube features a set interference fit
tolerance to mate with the head end disc which
has a correlated external stepped profile.
They are stepped to ensure perfect load-
bearing alignment when pressed and swaged
into position.
There is no welding process involved in the
manufacture. This avoids distortions from the
different cooling rates, and matrix destruction –
a property inherent in steel that causes ‘Rotting’
which presents itself as a high corrosion rate at
the junction of the weld.
Problem Solution
Excessive loads,
Overheating and Brinelling7
. This failure group is
related to the damage that occurs to the
bearing’s surface once its elastic load limit has
been exceeded. (Elastic load limit is the amount
of force a material can take and still return to its
original shape once the force has been removed)
The smooth surface of the bearing is galled and
fine particles of metal begin to break away. Once
this starts, the bearing will quickly heat up and
weaken the properties of the lubricating grease,
which leads to thermal runaway and self-
destruction.
Our bearing never exceeds its elastic limit,
since at >94 kN the bearing has a much higher
rating than the task requires. This has the
added advantage of greatly extending the
normal fatigue B-10 life limit specified by the
manufacturer.
The low TIR and MIS ratings of our idlers also
extend the bearing life by reducing continuous
mechanical impact loadings, but maintaining
sufficient load to eliminate the skidding of the
rotating elements that form the bearing.
7 Localized surface corrosion; a cause of damage to bearings
4

Problem Solution
Misaligned Structure.
Idler Sets and the operating environment can
contribute to idler work loadings that are
outside their specified parameters.
These loadings can drain energy and increase
maintenance levels. They are typically the
result of poor design or poor installation.8
This has led to an industry practice where
short lived rolls are being hidden in the
financial reporting as consumables, instead of
being listed as failing assets.
Traceability is the key to identifying poor alignment
and other structural problems in a conveyor
system.
All our rolls have a unique serial number on every
head end disc.
We record these numbers and associated
information in a database for complete traceability.
Problem Solution
Poor Handling
This occurs during transport from the
manufacturer to site and during installation and
can distort tube, distort bearing housings and
damage bearings.
Testing by D.R. Watson and J. Van Niekerk of
South Africa has shown that a force of
approximately 2 tonnes was sufficient to cause
plastic deformation of a 3mm thick end cap on a
standard roll.
This then increased the TIR reading and added
to the out of balance forces. The rolls
subsequently responded with poor performance
and reduced life span.
Our rolls feature machined ends which are
designed to tolerate a 10 tonne load without
plastic deformation. They are also 60% lighter
in construction, which means there is less
weight to transport.
A lighter roll is easier to manhandle and
therefore less likely to be dropped. Lower mass
also reduces OH&S issues associated with
extended stretching to reach the roll installation
position.
8 A conveyor belt can run true with idler rolls in +/- squareness state balancing the tracking of the belting within limits. This is not
a recommended method to track a conveyor belt for longevity.
5

Improved TIR and MIS
Problem Solution
TIR, MIS, and idler performance.
TIR is a measurement of the gross out of
radius dimension of an idler. It measures
ovality and bending of the shell tube.
When installed, poor TIR places a continuous
shock load on the bearing with every
revolution of the idler. It also creates a
flapping effect in the passing belt as it is lifted
and lowered on each revolution of the idler.
This phenomenon is evidenced by vibration
and noise. As this energy is transferred into
the supporting structure, it strains and can
eventually fracture, substantial support
fabrications.
MIS is the surface finish correctness to
radially differences as a slope plane generally
taken @ 6 minutes of rotation angle and these
sloped surface imperfections have been found
to directly correlate to the noisiness of the
idler’s interaction with the belt above it.
As noise is generated by a vibratory force,
any noise requires energy for generation and
as such is placing more stress on the
bearings and associated structural
componentry.
Both TIR and MIS readings refer to the roundness
of the pipe outer shell. The design of our roll
ensures pipe roundness via the following
protocols:
a) High levels of quality assurance ensure that the
original pipe is manufactured to true roundness.
The final process in the manufacture is to draw
the pipe through a set of round dies. This
compression through the dies ensures a high
quality and repeatable raw round product.
b) During the manufacturing process, all
machining of the pipe occurs within the grip of
close tolerance collets instead of three or four jaw
chucks. This removes distorting forces during the
end machining process.
c) Close tolerance machined profiled steel head
ends are interference fitted and act as a ‘Truing’
die to force any distortion of the tube shell to well
within the pipe to maintain the true roundness of
the pipe. The swage pressure fits the pipe to the
head end disc bearing housing.
d) No welding process is employed that would
distort roundness through uneven heating and
cooling.
All our rolls are “weigh scale” rolls, without
modification ex production.
Improved Rim Drag
Problem Solution
Rim Drag & Idler performance.
Rim drag is the amount of force needed to turn
an idler in Newtons. This force is multiplied by
the speed of the conveyor in meters per
second, to determine the energy required to
turn the idler in watts. Lower rim drag, means a
lower power bill.
The unique and patented construction, of our roll
eliminates the need for elaborate bearing seals.
These seals are a major contributor to rim drag
because they have only one external side
bearing lubrication contact lip seal.
6

Tougher material
Problem Solution
Material used and idler performance.
Typically rolls are made of the lowest grade
carbon (black) steel. However to perform
effectively and last longer rolls need to be made
of steel with a much higher tensile strength.
Not only will this tougher material provide
superior wear characteristics it will also deliver
much improved surface smoothness.
However, if an idler surface is too smooth, it will
slip against the belt creating flat spots and heat
in the idler. (This is an issue with high grades
304-309-316 & 318 stainless steel rolls that
‘surface work-harden’ to a shiny surface
polished finish.) A material is required that
combines a longer life wearing resistance, a
hardness to reduce bending distortion, with
sufficient frictional surface corrosion, to ensure
roll rotation and belt control travel
alignment(Tracking) guiding is maintained and
that work hardening surface polishing and
consequential belt slippage and wander do not
occur.
We use Vitresteel which has a yield strength that
is >3 times that of carbon (black) 200LO 200-
250 mpa grade steel and a tensile strength that
is >2.7 times that of 350 mpa grade high tensile
carbon steel and stainless steels.
This tougher material provides superior wear
characteristics. The wear characteristics of an
idler shell are not only related to toughness, but
also surface smoothness.
At the microscopic level, if an idler surface is too
smooth, it will slip against the belt creating flat
spots and heat in the idler. (This is an issue with
High grade stainless steel rolls that surface work
harden to a shiny polished finish.)
The unique blend of alloys in Fused Ferric
Modified Stainless Steel combines a longer
wearing hardness with sufficient surface
corrosion, to ensure that work hardening surface
polishing and consequential belt slippage and
wander do not occur.
Less Weight
Problem Solution
Impact of idler roll weight.
When considering the true cost of any piece of
equipment, one cost that is often
underestimated, is the cost to human well-
being.
Some of these OH&S effects are not
immediately obvious. Heavier components
increase the risk of injury when being manually
handled.
Conveyor idler change out is a unique situation,
where it is difficult or too expensive or
impossible to gain access to provide
mechanical assistance.
By eliminating the central solid or heavy hollow
steel bar axle shaft in the idler, our roll offers a
reduction in weight of up to 60% over a
conventional unit.
When being manually handled heavier
components increase the risk of personal injury.
Conveyor idler change out is a unique situation,
where it is difficult or expensive to provide
mechanical assistance.
With our roll the weight savings versus
conventional rolls become even greater in as the
shell face length increases
7
8

Shell to end weld failure
Problem Solution
When a standard idler fails at the welded joint, the
spinning bearing housing, acts like a ‘Pizza
Cutter’. This spinning sharp jagged edge, scours
and cuts the covers and carcass of the belt,
occasionally shredding the belt into useless lineal
strips. The remaining tubular shell becomes holed
and becomes a ‘Potato Peeler’ shaving the
covers and finally the carcass.
The construction of our roll does not weld the
bearing housings into the end of the pipe.
We use a proprietary process whereby a
groove is machined into the bearing housing
and the pipe is then mass swaged
(compressed) into this groove with a hydraulic
press.
This creates the distinctive rolled pipe ends of
our idler. These rolled ends eliminate any sharp
edges which can cause belt cover and carcass
damage.
8

Solution 2
Innovation that dramatically reduces roll replacement time, cost and risk.
Key issues:
- Fixed idler sets for idler rolls
- Technically qualified staff
- Work in ‘hazardous areas’
- Disruption to operations and production
Fixed Idler Sets
Problem Solution
These generally require complete removal
and to be stood aside for roller replacement
prior to re installation under the conveyor.
When in operation many of these are subject
to being clogged with dust dirt and other
debris.
All of the above is time consuming and
hazardous during changeover.
The straight cross-member is also subject to
overload and impact bending damage which
locks the shaft mounting ends making roll
removal difficult. Bent cross-members also
alter the belting cross profile. This causes the
loading to be transferred to adjacent idler
sets and. As a result, contact friction is
reduced dramatically causing skimming and
flat spotting – further maintenance issues to
be dealt with during maintenance. Resultant
structural damage can be significant.
The ideal idler roller frame needs to
accommodate the requirements for roll
changeover simply and effectively.
Typical fixed frame roll change outs can take
up to 2 hours per frame dependent on
complexity of the location.
This time needs to be significantly reduced if
improved productivity is to be achieved.
Our Idler Roll Assembly process during
maintenance or change out is as follows:
The assembly is lowered away from the
belt for maintenance and the rolls, housed
in cassettes, slide out. The hazards of
pinch points are eliminated by this process
which also relieves frictional contact. The
rolls then slide out easily on the curved
slider beam. Because of the curved profile
of this beam, any overload situation or
other impact flexes the beam which
returns to profile as soon as the overload
situation has passed and the cross profile
remains intact.
The idler slider beam hinges from one
side, and is located in place by a cam
locking mechanism. A safety lock pin is
then removed, using a shifter and small
lifting device to lower the slider beam
down on one end. This unloads every roll
in the line clear of the belting and as a
result all pinch point hazards are
eliminated.
9

Technically qualified staff
Problem Solution
Specialised equipment and technically qualified
staff are required since belt lifting equipment
must be deployed. This requires planning and
organising the suitable resources - which may
be better deployed elsewhere on site with other
work commitments
Idler roll replacement should be carried out
using relatively unskilled labour
Our idler rolls can be serviced or changed
out without the need of proprietary lifting
equipment or machinery by semi-skilled staff
The mine has the option to continue to
operate the conveyor belt during change
out9
Work in ‘hazardous areas’
Problem Solution
This includes working in areas such as between
the conveyor’s fixed assemblies requiring the
conveyor belt to be raised for change outs.
The ideal roll change-outs would avoid
obvious work hazards and severely mitigate
risks to human well-being.
Idler roll maintenance is completed from
only one side of the conveyor belt, where
currently maintenance has to be from both
sides
9 See Foot Note #3
10

Disruption to operations
Problem Solution
The enforced and lengthy shut down of the
conveyor belt to make roll change outs.
Roll change-outs, in the ideal world, would be
conducted without stoppages to the conveyor
belts and subsequent impacts on productivity at
the same time reducing OH&S risk.
The purpose of the Idler Assembly is to
replace the use of fixed idler frames and
replace them with a movable idler assembly
to avoid having to lift the conveyor belt for
idler roll change outs. This can then reduce
shut downs and lengthy delays and unsafe
change out methods that can arise through
roll change outs.
Conclusion
- Our Idler Roll design combined with patented technology provides significantly extended
roll life
- Our highly innovative Conveyor Idler Assembly c/w cassette methodology reduces
changeover times by at least 90% and can be used while the conveyor is running.10
- Both these solutions provide miners and bulk materials handlers a means of significantly
improving productivity leading to significant enhancement to EBITDA
- Miners are looking to protect/enhance margins by improving productivity and reducing
costs. Our products provide simple, straightforward ‘Capex light’ solutions.
- Our Idler Roll design combined with patented technology provides significantly extended
roll life
10 See Footnote #3
11

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