Australian Bulk Handling Review September/October 2021

www.bulkhandlingreview.com

VOLUME 26, ISSUE 5 | SEPTEMBER/OCTOBER 2021

In this issue: Conveyor showcase Reducing your dust emissions Choosing condition monitoring

THE ORIGINAL LOW PROFILE FEEDER

Reliable. Tested. Safe.

Radar for exact levels in bulk solids applications From simple to challenging: With radar technology that is highly robust, flexible and economical all at the same time, VEGA is putting things on track to ensure more reliable and efficient production processes involving bulk solids – of any kind and any grain size.

Due to our decades of experience we understand the requirements of the industry quite well. That’s why VEGAPULS level sensors are able to deliver exact measured values even when conditions get extreme because of dust, noise or buildup.

www.vega.com

CONTENTS SEPTEMBER/OCTOBER 2021

20

36

40

46

6 Industry news

24 Detecting the invisible

38 Oli Vibrators bust transfer chute buildup

12 Altra Motion brings backstop solutions to Australian mining

54 BULKtalk: Condition monitoring of belt conveyors

40 Delivering Aquila’s overland conveyor

14 Optimising uptime with OPTIME

59 A deeper understanding of conveyor pulley friction

16 Goya Foods ups output with 16 automated bulk bag dispensers 18 Nelson Silos expands to keep up with booming demand 20 Tribotech develops a polymer roller that lasts longer than steel 22 Vortex designs diverter chute for abrasive materials

CONVEYORS 26 Conveyor showcase

36 Optimising your conveyor’s backbone

44 Conveyor belt cleaner tension: A key to optimal performance 46 Different horses for conveyor courses

28 Evaluating the indentation rolling resistance performance of conveyor belt covers 32 Conveyor idler noise

42 Fixing the flaws of poorly designed transfer points

DUST CONTROL 48 Defeating dust with simple physics 50 Don’t let dust issues get the better of your process

www.bulkhandlingreview.com

VOLUME 26, ISSUE 5 | SEPTEMBER/OCTOBER 2021

In this issue: Conveyor showcase Reducing your dust emissions Choosing condition monitoring

USING THE BEST OF BOTH WORLDS TO CREATE SOMETHING BULLETPROOF Using the best of both worlds to create something bulletproof When an ore handling facility in the Pilbara, Western Australia, was undergoing a major upgrade, it reached out to conveyor manufacturer Transmin for help. The company’s low profile feeders were used to reduce the sites maintenance downtime and improved safety. ABHR speaks with Damian Thorpe, Transmin’s Product Manager – Feeders to learn more about the technology.

THE ORIGINAL LOW PROFILE FEEDER

For the full story, see page 10.

Australian Bulk Handling Review: September/October 2021 І 3

XXX

AUSTRALIA

EDITORIAL

AUSTRALIA

REVIEW

Published by:

11-15 Buckhurst St South Melbourne VIC 3205 T: 03 9690 8766 www.primecreativemedia.com.au Publisher Christine Clancy E: christine.clancy@primecreative.com.au Editor William Arnott E: william.arnott@primecreative.com.au Business Development Manager Rob O’Bryan E: rob.obryan@primecreative.com.au Client Success Manager Janine Clements E: janine.clements@primecreative.com.au Design Production Manager Michelle Weston E: michelle.weston@primecreative.com.au Art Director Blake Storey Design Kerry Pert, Madeline McCarty Subscriptions T: 03 9690 8766 E: subscriptions@primecreative.com.au

One must imagine Sisyphus handling REVIEW

In ancient Greek mythology, Sisyphus was punished for his crime of cheating death twice.

According to the legend, he was forced to roll a massive boulder up a steep hill every day, but just as he neared the top it would roll back down to the beginning.

Naturally, if he had an overland conveyor system the job wouldn’t have been much of a punishment.

While initially somewhat absurd, the concept of doing the same thing repeatedly and meeting failure is an all too common one. In fact, it’s often self-inflicted.

Design flaws can become baked into a bulk material handling system and lead to problems like spillage, increased dust emissions or damaged components. Fighting against the inertia of an entrenched system often requires workarounds, whether it is adding a vibrator to improve flow or redesigning a chute to reduce wear.

The benefits of putting down the boulder and finding a smarter fix can be immense, saving operators significant amounts of money when it comes to operating expenses.

Luckily, unlike Sisyphus most aren’t trapped by ancient gods. Finding out what is causing the boulder to get pushed back down the hill and either putting a stop to it or finding a work around will often work out much better in the long run.

In this edition of Australian Bulk Handling Review, we feature our first ever conveyor showcase, dedicated to showcasing the companies that help others move their own less metaphorical boulders from one place to another.

In the next edition of the magazine, we will be featuring stories about grain and powder handling, conveyor maintenance and a look at things to come in 2022. If you would like to get involved, please get in touch.

www.bulkhandlingreview.com The Publisher reserves the right to alter or omit any article or advertisement submitted and requires indemnity from the advertisers and contributors against damages or liabilities that may arise from material published. © Copyright – No part of this publication may be reproduced, stored in a retrieval system or transmitted in any means electronic, mechanical, photocopying, recording or otherwise without the permission of the publisher.

4 І Australian Bulk Handling Review: September/October 2021

William Arnott Editor - ABHR

teams with “We do what we say”

Masaba’s mission “to design and build rugged equipment for the world" MAGNUM telescoping conveyors  39 - 58m reach

 Low profile feed options

 900 - 1200mm belt width

 Swing or folding axle

Ship loading Mining Quarrying Infrastructure etc

The MCS finish Also • Truck unloaders • Transfer conveyors • Radial stackers • Stationary conveyors • Custom conveyors (please ask)

Matched hoppers, dust covers, walkways, paint & coating, etc

CONSTRUCTION

SHIPPING 4142

Mobile Conveying Services Pty Ltd PO Box 608, Narangba Qld 4504 1300 665 409 631 Uhlmann Road, Burpengary QLD 4505 enquiries@mobileconveyors.com.au www.mobileconveyors.com.au

NEWS

thyssenkrupp sells mining business to FLSmidth The business unit employs around 3400 people and generated sales of around $1.28 billion in the 2019/20 financial year.

THYSSENKRUPP WILL SELL ITS mining business to Danish company FLSmidth for around EUR 325 million ($522.6 million) as part of its realignment strategy. thyssenkrupp allocated the mining business to the multi tracks segment in October 2020 to find a new owner.

The business unit employs around 3400 people and generated sales of around $1.28 billion (EUR 800 million) in the 2019/20 financial year.

The company aims to transform itself into a high-performing group of companies with independent businesses, a lean holding company and a focus on systematic performance improvement across all businesses. thyssenkrupp AG CEO Martina Merz says the successful sale of the Mining business shows it is pressing ahead at

full speed with the transformation of thyssenkrupp.

“But we have not yet reached our goal. The principle ‘Performance first’ continues to apply. We need to return to positive cash flow as quickly as possible.

The sale of Mining Technologies makes an important contribution to this,” Merz says.

“At the same time I am pleased that we have found a very good new owner in FLSmidth. FLSmidth presented a convincing business strategy and a clear vision for the Mining business. It will give our employees attractive prospects.

That was extremely important to us when negotiating the sale.”

FLSmidth CEO Thomas Schulz aid thyssenkrupp’s Mining business is an ideal addition for FLSmidth.

“We are particularly impressed

6 І Australian Bulk Handling Review: September/October 2021

by the capabilities, expertise and reputation of the thyssenkrupp employees, especially in projects and products,” Schulz says.

“The large global installed base offers great potential for the service and aftermarket business. We have similar business models, share a strong focus on sustainability and digitalisation and our corporate cultures are a good match.

“As a result, I am very much looking forward to combining our strengths; I am convinced that together we will play a leading role in shaping a zero-emission future for the mining industry and in creating sustainable growth for our customers, employees and shareholders.”

The transaction is subject to competition authority approval. The closing of the transaction is expected within the next 12 months.

NEWS

Cement producer installs moisture measurement sensor TO PRODUCE CEMENT, A GERMAN manufacturer required sand, taken either from internal storage facilities or delivered by ship.

However, it found that the material had a much higher moisture level when it was transferred across the water.

Previously, the company checked the material moisture manually in the laboratory, but this was often slow.

surface and capillary moisture, which influences the specific conductive capacity of a material. This can then be compared to an averaged bulk density to determine if investigation is required.

In the result of a material process failure or caking around the sensor, an alarm can be sounded to ensure the validity of the measurements is always high.

To solve this, it installed SWR Engineering’s M-Sens 3, a microwave sensor specifically designed for continuous moisture measurement of solids during batching.

The sensor monitors product flow for moisture content and temperature, which can be used to detect how efficient the product stream is. Dusts, powders, granulate and other bulk solids can be constantly analysed to identify process failures, such as a defective screw or material clogging.

It does so by monitoring the material’s

The cement manufacturer installed the M-Sens 3 directly on the conveyor belt with a shuttle to continuously monitor the moisture content of the sand.

The work required to take samples and check the moisture level in the laboratory is no longer necessary, saving time and costs.

On a conveyor belt system, the M-Sens 3 can measure moisture of the solids and allow operators to react in real time if material is too humid or dry, helping prevent plugging of aggregates. Additionally, when

The M-Sens 3 monitors product flow for moisture content and temperature.

mounted at a bin’s outlet, it can take advantage of the constant bulk density and almost unchanging measuring field for monitoring residual moisture.

This helps operators stop material that is too damp from reaching the next production level.

The system itself has been designed for easy installation and calibration. All an operator needs to do to calibrate the sensor is press a button and enter the referenced moisture content. Measured fluctuations in bulk density and temperature are automatically compensated by an internal filter function.

Central QLD coal mine set to expand A CENTRAL QUEENSLAND MINE will soon expand its operations, creating more than 150 jobs in the process.

The sale agreement between MetRes – a joint venture between Stanmore Coal and M Resources – and Peabody Energy Australia would allow the restart of the Millennium and Mavis Downs coal mines near Moranbah.

Resources Minister Scott Stewart says this venture will create more than 150 jobs through investment in underground expansions and completion of rehabilitation obligations.

“With a predicted mine life of 22 years including rehabilitation, these are lasting jobs and will create long-term royalties

that will benefit all Queenslanders,” Stewart says.

“This investment is a strong sign of the growing confidence in our resources sector as Queensland continues its road to economic recovery.”

Queensland’s Stanmore Coal purchased their first open cut coal mine off Brazil’s Vale and Japan’s Sumitomo in 2015.

As part of the sale, Stanmore took on a $32 million rehabilitation obligation associated with the mine.

The Millennium and Mavis Downs mines will feature a mix of open cut, high wall and underground mining methods used for the extraction of high-quality metallurgical coal.

The project will have a total production of 13.9 million tonnes of metallurgical coal during its lifespan.

Stewart says the Queensland Government would continue to support the resources sector for the royalties and jobs it generates.

“The resources sector supports more than 84,000 jobs across Queensland and represents $44 billion in exports,” he says.

“The sector has played a vital role in supporting jobs during the pandemic and will continue to do so into the future.

“Queensland is naturally blessed with the world’s highest quality metallurgical coal, which the world needs to make steel.”

Australian Bulk Handling Review: September/October 2021 І 9

COVER STORY

Using the best of both worlds to create something bulletproof Transmin’s low profile feeders combine the benefits of belt feeders and apron feeders to give Australian mining companies enhanced flexibility.

WHEN AN ORE HANDLING FACILITY in the Pilbara was undergoing a major upgrade, it reached out to conveyor manufacturer Transmin for help.

As part of the upgrade, a mobile reclaim hopper was to be installed at the tail end of the operations to recover dead material within the stockyard. It needed a hopper that was safe, user friendly, versatile, and didn’t need constant supervision.

The hopper handles up to 2500 tonnes per hour of iron ore and is capable of being loaded by front end loaders on opposing hopper side edges at the same time.

Transmin designed, fabricated, assembled, and commissioned the reclaim hopper to the clients’ specifications, using its low-profile feeder (LPF) technology to reduce maintenance downtime and increase safety at the site.

Damian Thorpe, Transmin’s Product Manager – Feeders, explains the LPF is a hybrid between a belt feeder and an

apron feeder, using the benefits of both.

“Apron feeders need a dribble conveyor underneath due to how the pans work. Often, there will be some leakage that needs to be cleaned up as a result. Using a belt eliminates this material leakage entirely,” he says.

“Transmin developed the technology over 15 years ago and has developed it through ongoing research and development to rightly claim the LPF as the most significant innovation in the heavy-duty feeder space for over 50 years.

“One of its main benefits is to allow a reduction in the overall height of the plant. Lower buildings reduce the structural requirements, keep civil costs lower, reduce the weight required, provide less wind loading and keep capital expenditure costs lower.”

According to Thorpe, with the right configuration an LPF occupies up to 40 per cent less vertical height than a belt or apron feeder, with the possibility of being even lower if needed.

One of the main benefits of the LPF is a reduction in the overall height of the plant.

10 І Australian Bulk Handling Review: September/October 2021

Transmin’s LPFs use two strands of chain to drive the system, eliminating potential belt tracking issues. As a result, the direction of the belt can be easily reversed. They are also relatively customisable, using a modularised design to speed up manufacturing and allows for both horizontal and inclined positioning.

Belt widths can be customised, with options between 800 millimetres to four metres. Transmin can also include preferred componentry such as belt scrapers/cleaners, motors, and gearboxes.

Thorpe says one customer wanted to replace a conveyor on their site with an LPF, as it required significantly less maintenance.

“We’ve designed the LPF to be durable, and that’s where it shines. It has a longer duration between major maintenance than most alternatives,” he says.

“Because there is a modular design, a lot of the componentry can be rotated

Belt widths can be customised, with options between 800 millimetres to four metres.

in and out of service. We use rotatable spare part sections, so instead of taking out smaller parts, we take out the larger part and replace it while refurbishing the part removed in our Worksop.

“This reduces downtime and allows for periodic maintenance without shutdowns. We aim to make life as easy as possible when it comes to repairs, because there is a lot to do during a shutdown.”

This durability is the result of years of improvements to the design.

Transmin’s workshop team, which also double as its service team, provide feedback from customers to the engineers to help improve the design.

Most of Transmin’s manufacturing takes place in Perth, using a dedicated team to provide additional support to the local industry.

Durability was one of the top priorities for Transmin’s customers, which is why the company has focused on developing a robust, easy to maintain machine. Stuart Taylor, who used the LPFs in the Karara Project in WA has described the machines as “bulletproof”.

“In fairness, the machine was used above and beyond its initial design spec and it’s never missed a beat. This thing is bulletproof,” he said.

Transmin LPFs include toothed sprockets that positively drives the chain to reduce belt slippage and mistracking. In-process weighing, flow control gates, various drive styles, belt protection bars, Kevlar impregnated belt, and wear liners can be included to help the machine fit the specific application. Its belting does not need to be continuous and can be supplied in modular sections to be joined by a mechanical joiner.

The company can also integrate its ProEdge belts, which use a hot vulcanised edge strip to increase the

bond between edge strip and the belt, further increasing wear life and reducing maintenance.

Thorpe says the product is constantly being finetuned.

“At the moment we’re investigating adding lightweight guarding to the LPFs. We’ve also seen the industry is interested in more advanced condition monitoring,” he says.

“We’re currently developing an Internet of Things-enabled condition monitoring solution for our line of rockbreakers and would love to roll it out across our other products.”

With the right configuration an LPF occupies up to 40 per cent less vertical height than a belt or apron feeder.

Australian Bulk Handling Review: September/October 2021 І 11

BACKSTOPS

Altra Motion brings backstop solutions to Australian mining Major mine sites are choosing Altra Motion Australia backstops to protect critical assets. ABHR speaks with Rex Sinclair, National Sales Manager, to learn more.

WHEN A MAJOR MINE IN REGIONAL NSW began installing its new conveyors, the operators needed a load-sharing, releasable backstop solution.

When fully operational, the massive facility produces around 17 million tonnes of coal each year. The mine’s long drift conveyor transports this coal from the longwall system underground to the surface. As part of its design, the conveyor also features an 80-metre lift.

The backstops needed to be installed along this conveyor, with additional backstops required for the mine’s surface ramp conveyor.

Rex Sinclair, National Sales Manager at Altra Motion Australia, says the company approached the Conveyor OEM to introduce its new Stieber Clutch

Stieber roller-type RDBR backstops

reducing torque peaks, preventing damage to the belt and mechanical components.

The soft braking control benefits and features include controlled braking independent of load and load position, braking on time or distance, adjustable brake ramp/curves, compensating for variable friction factors, controlled startup, and real-time monitoring of brake sequence time.

Stopping too hard can cause the material to spill or damage the belt itself, often one of the most expensive pieces of equipment. The SOBO avoids potential flow-on effects, such as blocked chute overflows and gives operators greater control over how the equipment will work.

Sinclair says the SOBO has helped Altra win a recent project, as it was the perfect solution for the customer.

RDBR-E torque-limiting/load-sharing releasable backstop technology.

“Unlike other backstop designs that offer limited reverse rotation after being engaged, the new Stieber design allows for a controlled release under load while providing virtually unlimited backward rotation for maintenance and clearing work,” Sinclair says.

“The RDBR-E features an internal torque limiter which is specially designed for use on the low-speed shaft of the driving unit in multi-drive systems, such as on large, inclined conveyors, where two or more backstops share the reverse load.

“The Stieber backstops were chosen to meet the tough conveyor application requirements due to their superior release functionality.”

with a bearing supported multi-disc brake for torque limiting and load sharing functionality. An optional release function allows for a controlled release under load while providing unlimited backward rotation for maintenance and jam clearing.

Altra Motion Australia, the local subsidiary of global company Altra Industrial Motion, has been active in the bulk handling space for more than 85 years. The company has a significant portfolio of high-profile, quality brands that provide mechanical, hydraulic, electromechanical, and pneumatic power transmission and motion control components and systems.

Altra Motion Australia offers the Svendborg Brakes Soft Braking Option (SOBO) IQ system to enhance backstop

“The SOBO is exclusive to Altra Motion; no other competitor offers it or a low-speed torque-limiting releasable backstop.

“Altra Motion is not only able to offer customised engineered product solutions, but we also offer a comprehensive service program to the customer to support the commissioned product on the conveyors.”

The service program includes product training for the customer and staff, 24/7 breakdown callout, planned and preventative maintenance, upgrades and retrofits, correct adjustments to OEM specifications, technical support, and a complete picture of the systems’ performance through documentation and data logging.

Altra Motion Australia is also able

Altra Motion Australia provided twin RDBR 300 models with 70-kilonewton metre torque per unit for the drift conveyor and a pair of RDBR 360 models with 120-kilonewton metre torque per unit for the ramp conveyor.

safety further. Svendborg’s unique SOBO provides a range of safety and durability benefits in heavy industrial applications.

Deceleration and the stopping of heavy conveyor loads are critical, and controlled braking is essential for significantly

to offer real-time Industrial Internet of Things solutions. Sinclair says these solutions optimise uptime and assist with predictive and preventative maintenance.

IIOT can be added to SOBO IQ and can also be adapted to any brake system.

Stieber backstops were chosen to meet the tough conveyor application requirements at the coal mine.

12 І Australian Bulk Handling Review: September/October 2021

COMMITTED TO THE SUCCESS OF YOUR OPERATION ONE SUPPLIER FOR THE LIFE OF YOUR CONVEYOR

Delivering peace of mind.

Making the best in class premium conveyor belts and Engineered Conveyor Solutions is what we do, but it’s our expert team that defines our brand. With so many moving parts and heavy loads, our highly talented engineers and customer support specialists are always available when you need them most.

Phone 1800 Fenner (336 637) www.fennerdunlop.com.au | sales@fennerdunlop.com.au

Local people, local manufacturing and the most upto-date technologies means that we are continually adding value to your operations.

Call our team for your Engineered Conveyor Solutions.

CONDITION MONITORING

Optimising uptime with OPTIME Schaeffler has designed a system that takes the guesswork out of the entire condition monitoring process – from installation to analysis with a single, out of the box solution.

CONDITION MONITORING IS KEY to success for most modern mines. It can help prevent catastrophic machine failure, optimise maintenance, and improve machine life.

However, these systems have been historically expensive to deploy and complex to install. According to bearing manufacturer Schaeffler, up to 95 per cent of all machines inside factories are only sporadically monitored, or often not at all.

Mark Ciechanowicz, Industrial Services Manager at Schaeffler Australia says one key issue is getting the inventory or spare parts and the logistics of getting human resources –whether they are internal or subcontracted – to the site.

“A lot of Australian mine sites are remote, which poses many challenges in terms of machine maintenance,” he says.

“And obviously downtime costs are a major factor, especially when commodity prices, such as iron ore prices, are at an all-time high. In these instances – where a mining company needs to be at maximum production to meet demand – they don’t want to be caught in a situation where a critical asset such as a conveyor system is down.”

Additionally, offline condition monitoring systems – which require the manual collection of data at specific time stamps – have their own limitations and challenges.

“If you consider the footprint of a mine site, it involves a huge amount of coverage – just one division might take a week to walk around,” Ciechanowicz says. “Offline collection is not only time-consuming and impractical; it will only provide a periodic snapshot of that machine’s health.”

Online systems can be scheduled to gather data at several points in a day, however not all are made equal.

Ben Kang, Schaeffler Australia’s Industry 4.0 and Engineering Solutions Manager, says cabled systems can be

The sensors are wireless, battery operated vibration and temperature sensors that come with a stainless-steel mounting pad.

complex to install when time is precious and become very expensive very quickly.

“Imagine the size of an iron ore site and the sheer amount of copper and resources required to cable those systems up. It has not been a costeffective solution for many mining operations,” he says.

This data then needs to be interpreted, which requires special expertise and comes with a host of additional expenses.

To address these challenges, Schaeffler has developed a comprehensive condition monitoring solution that is both easy to set up and highly cost efficient for bulk handling operations.

Called OPTIIME, the system is a wireless online solution that uses inbuilt algorithms for expert diagnostics of rotating equipment, without the need for a user. This lets customers know if there will be an issue far in advance, and the steps they will need to undertake to resolve them.

Ciechanowicz says this means the user spends less time on the analytics side, and more time actioning the results that come out of the system.

“What it affords the customer is time to be able to plan maintenance, inventory,

14 І Australian Bulk Handling Review: September/October 2021

and in a proactive sense conduct maintenance on their terms rather than the machines dictating what they do in a reactive sense,” he says.

What sets the system apart is its ‘plug-and-play’ nature. OPTIME is made up of three parts, the sensors, a gateway, and the digital services. To set the system up, a user needs to download the OPTIME smartphone app and connect the gateway.

The sensors are wireless, battery operated vibration and temperature sensors that come with a stainlesssteel mounting pad that can be glued onto the surface or bearing housing of a rotating machine. They are activated via a mobile smart device using Near Field Communication (NFC) and automatically connect to the gateway and to other sensors.

Ciechanowicz says the process of setting up each sensor is exceptionally fast, taking about five minutes.

The gateway collects data from the sensors and transmits it to the cloud, using a specialised, independent, mesh network.

Customers can then use the app to access the digital services, which includes the in-built algorithms that analyse data and provide diagnostic reports.

“The app has been designed so the customer can do everything on the app, from provisioning the gateway and sensors, to adding meta data,”

more meta data the customer puts in when they set up the sensor – and they can do this retrospectively – the more accurate that analysis is going to be.”

He adds that customers do not require any condition monitoring experience to start benefiting from the diagnostic reporting.

“This is quite unique given that most systems require some kind of condition monitoring savvy to be able to set them up and then to interpret the data,” he says.

All the sensors automatically connect with each other and can act as repeaters.

This means sensors could be hundreds of metres away from the gateway, scattered across a wide area and still reach the cloud.

Kang says OPTIME and all its inbuilt smarts is the result of Schaeffler’s extensive technical expertise as a world-leading solution provider for rotating equipment.

“This is a solution that has been designed and manufactured by a technology company which has its roots in roller bearings,” he says.

“The outputs of this system will be vastly different from other wireless systems that don’t have Schaeffler’s foundation in rotating machinery.

Ciechanowicz says.

“The system algorithms work off an intrinsic library – for example, if the customer types in a bearing designation, the system can work out the kinematic frequencies or the fault frequencies and use that in the diagnosis. Essentially, the

OPTIME has also been designed from the ground up to be deployed in large volumes across a plant.

Schaeffler expects the sensors to be measuring hundreds or even thousands of machines, with operations able to quickly scale up if needed.

All of these algorithms have been developed on top of years of automation, analysis, machine learning and artificial intelligence. And they work seamlessly behind the scenes to give customers clear, easy-to understand insights that they can action instantaneously.”

OPTIIME is a wireless online solution that uses in-built algorithms for expert diagnostics of rotating equipment.

Government incentives available now Now is the time to invest in automated packaging and get your business ahead.

You could save tens of thousands through two Australian Government schemes.

Learn more at aurora-process.com/incentives

Rural and City. Australia Wide NZ 0800 55 77 33 | AU 1800 318 019 | sales@aurora-process.com Bag & Sack Filling | Closing | Conveying | Palletizing | Wrapping | Semi & Fully Automated Systems

BAGGING

Goya Foods ups output with 16 automated bulk bag dispensers When a major US food company needed to up its production, it turned to the Flexicon Corporation to equip its new site. and flour lines at the previous site while outfitting the new site with more efficient bulk handling and packaging equipment from Flexicon.

“We had Flexicon equipment here already, so we knew they were reliable systems,” Valencia says.

“Efficiency is the focus because the product and process demand it. The processes are relatively uncomplicated, so the simpler the process, the higher our efficiency must be. We’re always looking to increase quality, safety and efficiency.”

Cutting bulk bag unloading times

A bucket conveyor moves material from two bulk bag dischargers to a weigh hopper.

GOYA FOODS IS ONE OF THE largest Hispanic-owned food companies in the United States, importing ingredients from around the world to create more than 2500 food products.

In 2015, the company opened its new headquarters and distribution centre in Jersey City, New Jersey. At the same time, it invested in its existing distribution centre in Secaucus.

At 22,300 square metres, the new site is four times larger than the previous facility and relieves several long-standing bottlenecks, says Luis Valencia, the new site’s Plant Engineer.

“We had run out of capacity for rice mixtures at our previous site. In fact, all of the existing lines, including the bean and flour lines, were over-utilised. We were overdue for a change,” Valencia says.

To prevent supply disruptions, Goya continued operating all 12 of its rice, bean

Goya receives rice, beans, dry vegetables, and flour in 998 kilogram bulk bags, while the spice mixtures are mixed into rigid 498 kilogram totes. Ingredients are batched to the packaging machines by gain-inweight control.

To increase productivity, Goya needed to accelerate its handling of bulk bags. The Bulk-Out BFC bulk bag dischargers use a cantilevered I-beam, hoist, and trolley to load bags quickly.

Valencia says the fast-loading units allow just two forklift drivers to serve the site’s 16 bulk bag dischargers. A single operator can load and discharge bulk bags across several product lines.

In operation, a forklift places a palletised bulk bag in front of the discharger. The operator connects the bag loops to Z-Clip bag strap holders on the lifting frame and, using a pendant, hoists the bag into the discharger.

Rice mixes batched to high-capacity pouch filler To match the production capacity of a new high speed pouch filler for rice mixes, Goya installed a gain-in-weight batching system for the rice, vegetable, and spice components. For rice, palletised bulk bags are delivered by fork truck to side-by-side

16 І Australian Bulk Handling Review: September/October 2021

BFC bulk bag dischargers that unload into two large 2268 kilogram capacity floor hoppers. The hoppers feed a common six-metre-long bucket conveyor leading to a weigh hopper which empties into the pouch filler. Each discharger unloads a 998 kilogram bulk bag of rice in four minutes.

Similarly, dry vegetables move from their respective bulk bag discharger to the pouch filler via bucket conveyor and weigh hopper.

Each weigh hopper rests on load cells that transmit weight-gain signals to a controller that stops each conveyor once the target weight is reached for each ingredient, automating, and expediting a process that previously required manual verification that batches reach the pouch filler.

Spices for the rice mixes are supplied in rigid totes, which are hoisted above a Model BFH-C-X half frame discharger mounted on a 1134 kilogram capacity hopper. From the hopper outlet, a 7.6-metre-long flexible screw conveyor is inclined at 32°, moving the spices to a weigh hopper which discharges to the pouch filler.

A flexible screw of specialised geometry for difficult-to-handle spices rotates within an 11.4-centimetre polymer outer tube of the flexible screw conveyor.

The screw is the only moving part contacting material and is driven beyond the point of discharge, preventing material contact with seals or bearings.

“Goya Foods Secaucus has received an A++ rating by the British Retail Consortium’s certified auditors, the highest, for two years in a row,” Valencia says. “In this case the conveyor is sanitised daily by disconnecting the flexible screw from the drive shaft and removing the screw for cleaning.”

The plant specified Flexicon flexible screw conveyors for both the rice mix

spices and flour lines because they are enclosed, simple, dust-tight and prevent the separation of blends.

Flexible screw conveyors transfer ingredients from the warehouse, through a packaging room wall.

Bean and flour lines operate at high capacity The bean line deploys six BFC model bulk bag dischargers, mounted over 2268 kilogram capacity floor hoppers and arranged in three pairs. Each pair shares a bucket conveyor that feeds a weigh hopper which discharges into a pillow-bag packaging machine.

The flour line employs three BFC bulk bag dischargers, each with Flow-Flexer bag activator plates that increasingly raise and lower opposite bottom edges of the bag on timed cycles, ultimately forming a steep V shape that promotes total discharge.

Dialling it in Goya Secaucus packages products of 50 different varieties of beans and 30 different flours. Each has slightly

different flow characteristics. “We change

is required. Flexicon helped us with

over constantly, and when you change a bean or a flour or a rice mix, there’s a lot of fine-tuning,” Valencia says. Fine flours are among the tougher products.

“It’s a challenge to dial it in; the higher the speed, the more precision

upgrading our electronics. They made sure the dischargers were feeding correctly and the controls were reading the hopper levels correctly. We control the weights better now and avoid process loss.”

World leaders with over 45 years’ experience in Belt Conveying Research and Consulting Belt Conveyor Component Testing Services including: FRAS tests according to MDG3608 and AS4606 Independent belt conveyor testing, audits and reviews Idler roll noise testing, including self-noise and operating noise Belt cover ply adhesion and resistance to tear propagation Cord breaking force, static & dynamic cord pull-out strength Small and large sample indentation rolling resistance measurement Belt surcharge angle and maximum inclination angle Belt scraper efficiency Idler roll rotational resistance testing, including rim drag, break-away force and maximum start-up drag, MIS and TIR of idlers Idler dust and water ingress Conveyor belt tensile strength and elongation Troughability

Storage, Feeding, Transfer & Belt Conveying Course 3-5 November (Perth)

Abrasion testing for idler and belt components Inspections and failure analysis, as well as site inspections Thermal imaging

www.bulksolids.com.au

Belt tests are conducted according to AS1332, AS1333, AS1334 & other associated standards. Idlers tested to SANS 1313, DIN22112 & MDG3608.

Design Audits conducted in accordance with ISO5048, DIN22101, CEMA & other in-house procedures.

SILOS

Nelson Silos expands to keep up with booming demand As Australia moves out of a period of drought, the improved weather conditions have led to a boom in demand for agricultural silos. Eric Nelson, Managing Director of Nelson Silos, explains how his company is keeping pace.

BUSINESS IS BOOMING FOR SILO manufacturer Nelson Silos, as farmers flock to increase their storage capacity.

Eric Nelson, the company’s Managing Director says the demand is partly due excellent weather conditions across the country.

“On the east coast, many of these farmers have just come out of a drought into near perfect weather conditions for growing,” he says.

“The price of grains and legume is also up significantly, which is improving profitability as well.”

On farm storage allows farmers to wait until they have a stronger negotiating position before they sell. Without storage, many farmers must sell their grain at harvest time when the price of grain is at its lowest.

Facing increasing demand, Nelson Silos has invested significantly into expanding its manufacturing facilities.

Nelson Silo’s farm silos are fully manufactured in the company’s factories before being shipped out across Australia.

Part of this has been installing a new paint booth at its main Rochester facility.

Instead of now spraying individual silos, the booth can handle two to three silos at a time. In addition, temperature controls allow Nelson Silos to dry the paint at a consistent 20°C. Nelson says the paint booth can also apply spray to the interior of silos with specialised coatings to act as corrosion inhibitors.

“These are mostly for our superphosphate silos, which use a steeper cone and have a more robust and larger outlet,” he says.

“Superphosphate, depending on its type, is hydroscopic which means it can clump together. It can also be highly corrosive, which is why the internal coating is so important.”

In addition, the company has installed four elevating towers, with another two planned. Nelson Silo’s farm silos are built to handle up to 200 cubic metres in capacity. They are fully manufactured in the company’s factories before being shipped out across Australia. The elevated towers allow easier access to bolt in wall sheets and

Additional cranes and equipment have also been purchased to handle the growing sizes of silos.

18 І Australian Bulk Handling Review: September/October 2021

place the roof section on the silo.

Additional gantry cranes have also been purchased to handle the growing sizes of silos. Nelson says the demand for taller silos has meant the business has had to adapt.

Transport plays a major role within the business. The company owns a fleet of eight prime movers and eight low-loader trailers, along with three heavy trailers.

This allows the company to deliver silos to Darwin, Port Headland or Kalgoorlie itself, instead of through contractors.

“We don’t use contractors because it gives us more control over the customer experience,” Nelson says. “Our delivery team can also do the installation side of things, with staff in the pilot cars for heavy transport vehicles.”

“That’s one of our secrets for reducing time spent on site. The people handling the installation have done it literally 50 to 60 times before.”

Nelson Silos is continuing further upgrade its manufacturing capacity.

As part of this, the company is looking into building another assembly factory in northern New South Wales to streamline assembly.

We pioneer motion

Optime - Plug. Play. Predict.

Condition monitoring can be expensive. Which is why up to 95% of all machines inside factories are only sporadically monitored, or often not at all. This can lead to unplanned breakdowns and downtime. OPTIME from Schaeffler allows for comprehensive condition monitoring that is both easy and affordable. Taking advantage of the simple plug & play installation, OPTIME allows you to start monitoring hundreds of rotating machines in just a few hours. With the ability to work on almost all machines, OPTIME can detect potential damage, imbalances or misalignments – even weeks in advance. This enables you to easily and conveniently plan your long-term maintenance, manpower or spare-parts requirements www.schaeffler.com.au

ROLLERS

Tribotech develops a polymer roller that lasts longer than steel Max Otis, Director of roller manufacturer Tribotech, tells ABHR how and why the company developed a plastic roller that can outlast steel.

WHEN MAX OTIS BEGAN researching the Australian mining industry in 2014, he was somewhat disappointed. According to him, many rollers were still being made and used the old-fashioned way, and innovation wasn’t up to standard at the time.

This was one of the driving forces behind the creation of Tribotech. The company is named after tribology, the science of interacting surfaces in relative motion, and focuses on developing innovative conveyor roller designs.

Otis says one of the main innovations the industry had welcomed was moving from steel to plastic rollers.

“This has been under way for the past 40 years or so, but the rollers haven’t changed much since then,” he says.

“The type of plastic used is often either polyvinyl chloride (PVC) or highdensity polyethylene (HDPE), which are quite economical materials. They’ve been used heavily in the plumbing industry for the same reason.

“We wanted to bring the engineering to a higher standard and use materials that were more exotic to find a better fit for the heavy-duty mining industry.”

Tribotech began trialling several different materials to build the rollers.

They were looking for one that provided optimal wear resistance, in addition to catering for maximum loads and ultimately a longer lifespan. In doing this, the company’s engineers investigated alternative industries, such as the aeronautics sector, to find a material that would make a viable roller.

After heavy research and development, Tribotech chose a particular polymer – and so Weartech was born.

Otis says Tribotech originally tested the Weartech rollers to be suitable for the

iron ore industry, which experiences the most problems with rollers. He details the initial methodology that was undertaken to combat the main challenges present in this area.

“Iron ore is extremely abrasive. It has a higher density than other materials and is typically carried at a higher volume.

This means that the tonnes per hour carried on the conveyor is the highest in the industry, which often leads to a higher rate of roller failure,” he says.

“Weartech offers all the benefits of plastic while also having the ability to outlast steel. The performance of the rollers that we’ve seen with this product has been unwavering.”

One example of this can be seen in a Pilbara iron ore mine, who trialled Weartech after a bad experience with PVC rollers. Due to a high failure rate caused by extremely high wear and tension on the conveyor belt, the client had previously decided to replace the steel rollers with PVC ones to reduce the risk of belt damage. This came at a cost, as the PVC rollers had a significantly lower lifespan, at around six to eight weeks.

Weartech offers all the benefits of plastic while also having the ability to outlast steel.

Tribotech manufactures the tubes in-house instead of having them externally manufactured, which reduces the long-term cost.

20 І Australian Bulk Handling Review: September/October 2021

Tribotech’s engineers investigated alternative industries, such as the aeronautics sector, to find a material that would make a viable roller.

Tribotech offers trials of its products to showcase its quality and reliability.

Tribotech proposed the client trial Weartech due to its weight and beltfriendly properties, and the results were immense. The rollers managed to outlast conventional steel rollers by a factor of seven.

Otis says the company decided to manufacture the tubes in-house, in

Western Australia, instead of having them externally manufactured, which reduces the long-term cost.

“We use our experience as a chemical company and make it all here, reducing the cost significantly.” he says.

“We also organise our production to manufacture the rollers in a short lead

time, as our customers rely on a 10 day or less delivery schedule. Every year we are looking for new innovations to reduce lead time and improve our designs.”

Otis is looking forward to continuing Tribotech’s journey in revolutionising the industry. The company readily offers trials to showcase the quality and reliability of their products to any mine sites who are experiencing issues with their rollers, or who just want to see what else is out there.

Bulk solids storage and handling solutions generated in Australia for Australian Conditions

Walla Walla, NSW

Toowoomba, QLD

(02) 6029 4700

(07) 4634 4622

www.kotzur.com

Perth, WA (02) 6029 4700

info@kotzur.com

CHUTES

Vortex designs diverter chute for abrasive materials Equipment manufacturer Vortex Global has built a pivoting chute diverter that can handle some of the most abrasive materials and applications.

EQUIPMENT BREAKDOWNS CAN lead to expensive production pauses, which is why industries handling abrasive materials tend to value durability.

Laurence Millington, Managing Director of Vortex Global, says end users in the mining, cement, and heavy industry sectors want longevity from their equipment.

“Nobody wants to be constantly repairing equipment every six months, they’re looking for something that will outlast everything else,” he says.

Vortex Global used this philosophy to design its pivoting chute diverter.

The diverter is used to move heavy duty or abrasive dry bulk solid materials from one source toward two or three destinations in gravity applications.

The body is constructed from carbon steel while the inlet and pivoting chute are constructed from abrasion resistant steel (minimum 400BHN) with other option available such as chromium carbide.

In addition, it has no interior seals, allowing it to handle materials of up to 200°C and above.

An industrial contractor in Australia handling clinker chose the pivoting diverter chute for its new cement facility, based on recommendations from other Vortex customers. The quarter-turn, electrically actuated Vortex Titan Pivoting Chute Diverter was designed to manage extreme abrasion.

It contained an inlet chute and internal pivoting chute made from abrasion resistant steel and liners. The diverter’s body was also protected by a specific paint that addresses local environmental conditions.

“Everything we build goes through a quality check to ensure the diverter

Vortex’s pivoting chute diverter is constructed from abrasion-resistant materials.

“Everything we build goes through a quality check to ensure the diverter or valve is working correctly before dispatch.” or valve is working correctly before dispatch,” he says.

If needed, however not supplied with this current diverter, all Vortex loading spouts, valves and diverters can be manufactured to ATEX requirements and dust zones.

To ensure the equipment maintains its longevity, the company has designed the chutes to be easy to maintain. It features a removable access panel for

22 І Australian Bulk Handling Review: September/October 2021

in-line inspection and maintenance.

Its parts are designed to be replaceable to prolong its service life. For larger systems, removable bars help maintenance crews remove internal components for easy inspection and repair.

Millington adds that Vortex Global offers around the clock support whether the customer is from the US, UK, or China, someone will respond to any issues or questions the customer may need answering.

“COVID-19 has made this slightly harder, but we’ve been able to support customers remotely over the phone or online.”

56 Paramount Drive, Wangara, WA 6065 Australia

•

SURAN CE AS

RVICES SE

(08) 6180 5762 info@tribotech.com.au tribotech.com.au

COM PASS

STEEL · WEARTECH COMPOSITE · HDPE · ALUMINIUM · IMPACT · RUBBER DISC RETURN · WEIGH

I SO

9001

•

SENSORS

Detecting the invisible When an MDF manufacturer needed a sensor that could accurately output the level of a silo containing wood flour or wood flakes, VEGA Australia’s Jim Curnow, was confident that the VEGAPULS69 Radar Level Transmitter could handle the job.

WOOD FLOUR IS THE VERY FINE wood or particle-board dust that is used to supplement natural gas burners. Wood flakes are further separated into wood fines or wood core to make particleboard.

The fines make the particleboard surface while the coarser flakes make the particleboard core. All of these products are stored in separate silos ranging from nine to 30 metres.

As part of the manufacturing process D&R Henderson, a particleboard producer, stored the very light, very dry powder in a 21-metre silo.

However, it ran into a problem.

Because wood flour is so light, fluffy and dry the traditional methods of measuring

the level just simply didn’t work.

Sheeshendra Deo, Electrical Manager at D&R Henderson says finding a sensor fit for the job was a process of trial and error.

The company first tried using an ultrasonic sensor, which emits acoustic pulses to detect the level in a vessel.

The light nature of the wood flour meant the pulse was being absorbed, which made the readings unreliable. On top of this, the ultrasonic sensor was affected by the airborne dust, further attenuating the signal.

“We tried a lot of sensors that just didn’t work,” he says. “The material had an extremely low dielectric, which meant it was a poor conductor of electric current.”

“Our product is also very dry.

Normally these sensors depend on having some moisture there to find an accurate reading.”

Jim Curnow, a Business Development Manager at VEGA Australia says radar

The VEGAPULS69 has a dynamic range of 120 decibels and can get a much better return signal from a low dielectric material.

24 І Australian Bulk Handling Review: September/October 2021

systems need at least some conductivity to work.

“The wood flour had such a low dielectric, it was basically invisible to the sensor,” he says.

The company tried several sensors, but none of them were able to accurately detect the material. One potential solution was to install load cells, but that would be prohibitively expensive and could be affected by the wind and other factors.

Attaining an accurate reading in the silo was vital for D&R Henderson.

If the company didn’t know how much wood flour it had, it could lead to lost production while refilling the silo. Since the product supplements natural gas in the burners (which run the wood dryers), the gas cost can be huge.

Eventually, the manufacturer began testing the VEGAPULS 69, one of VEGA’s most advanced radar sensors. Wood flour was one of the materials VEGA claimed it could accurately measure.

Curnow says the 80 gigahertz radar

D&R Henderson stored the very light, very dry powder in a 21-metre silo.

was different to the others the customer had tried, as it has a much higher dynamic range, meaning that it was a lot more sensitive, enabling the unit to receive and process very small echoes from this type of material.

“The VEGAPULS69 has a dynamic range of 120 decibels. All of the other radars at the time were using around 85 decibels for measurement,” he says.

“The decibel scale is logarithmic. That means going from 85 to 120 isn’t just a 25 per cent increase – it’s over 1000 times more sensitive.

“That means the sensor can get a much better return signal from a low dielectric material and makes it for all intents and purposes immune to dust and buildup.”

material could gather.

The sensors require no maintenance and can be set up and left alone.

Integrated Bluetooth technology means the VEGAPULS69 can be programmed and integrated from the ground by site staff using their mobile phones, without the need to climb a 21-metre ladder with a laptop to make a program change.

Deo says VEGA made sure to take samples of the wood flour from the site to see if the sensors would work.

“They took various samples, and we were confident that it would work after seeing the results,” he says.

“We then began to replace all of the other sensors across the site with ones from VEGA and have close to 10 now installed.”

One feature that helps protect the system from dust and buildup is the lack of a horn. Traditional Radar sensors often use a horn to focus the microwave beam into the right direction. The VEGAPULS 69 uses a lens antenna rather than a horn, removing an area where

Curnow says the consistency of VEGA’s products is key to its success.

“They’re all German made to very high standards. I’ve been to the factory and seen the level of quality control that goes into every single step of the process,” he says.

“It’s really high tech and impressive, and it means that everything we produce will operate as it should.”

The sensors require no maintenance and can be set up and left alone.

MARTIN® CLEAN BELT SYSTEMS & SERVICES Eliminate material carryback and increased cost of operation involving manual cleanup, damage to belts and systems, and downtime and lost production.

Martin® factory-direct clean belt systems and services ensure your conveyor belts are cleaner, safer, and more productive by providing unsurpassed cleaning performance and remote monitoring with industry-leading technology, experience, and knowledge.

Learn more at

martin-eng.com.au

Australian Bulk Handling Review: September/October 2021 І 25

® Registered trademark of Martin Engineering Company in the US and other select locations. © 2021 Martin Engineering Company. Additional information can be obtained at www.martin-eng.com/trademarks and www.martin-eng.com/patents

CONVEYOR SHOWCASE

Open troughed belt conveyor, closed pipe conveyor, U-shape conveyor, bucket elevator

BEUMER Group GmbH & Co. KG

info@beumer.com

+49252124-0

•

STUDIO TECNICO MALNATI S.a.s. BMH Rappresentanze Industriali

giovanni.malnati@stmalnati.com

3487013414

•

MECEBA

babayigit.cevdet@yahoo.com

905323209042

•

WA Belting Solutions

david@wabelting.com.au

1300651320

•

NRC Industries Limited

psbhawal@nrcconveyor.com

919830250122

•

Dos Santos International, LLC

info@dossantosintl.com

+1 770 423 9895

•

R BRUNONE

brunone@brunone.fr

(00) 33 2 32 64 20 20

Tega Industries Limited

sandip.de@tegaindustries.com

919051498639

Rall Conveyor Enginnering

contacto@rallingenieria.com

56987466947

•

•

•

•

A. R Brenya Company Ltd

arbrenyacompanyltd@gmail.com

233557504815

•

•

•

•

Vayeron Pty Ltd

info@vayeron.com.au

1800404160

•

Floveyor

jess.l@floveyor.com

+6189378 3333

STM SpA

stm@stmspa.com

233557504815

TUNRA Bulk Solids

enquiries@bulksolids.com.au

61240339055

•

•

• Plastic Modular

Sandwich Belt high angle conveyors

Services of engineering

IOT condition monitoring for bulk handling belt conveyors Aeromechanical

Not conveyor manufacturer, testing services provider.

PRIME PRECISIONS rajulu@primeprecisions.com

919677737122

Tecnipak

mineria@tecnipak.com

+56 2 24965600

KAUMAN

kauman@kauman.com

34678754615

•

Bulk Connections

sifison@bulkconnections.com

27314669618

•

DYNA Engineering

dyna@dynaengineering.com.au

08 9473 4300

•

Bridgestone Mining 461 Dundas Road, Forrestfield, Solutions Australia WA 6058

400066505

•

Finlay Screening & Crushing

ggrigson@finlay.com.au

07 38881777

•

Promet

info@promet.com.au

08 9249 8749

Premron Pty Ltd

sales@premron.com.au

07 49722982

Kinder Australia Pty Ltd

conveyorsolutions@kinder.com.au +61 3 8587 9111

26 І Australian Bulk Handling Review: September/October 2021

Other

Pneumatic

Company Phone Number

Chain

Company Email Address

Belt

Company Name

What type of conveyor do you manufacture?

Screw

Business Details

•

•

•

•

APRON FEEDER

Rubber conveyor belt with fabric and steel reinforcement •

•

•

We distribute Terex belt conveyors.

•

•

Rollers

Scrapers

Belts

Pulleys

Pulley Lagging

Walkways

Lacing

Skirting

Guards

Impact Beds

Wear panels

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

• •

•

• •

Other

Idlers

What type of conveyor components do you manufacture/distribute?

• •

•

•

•

•

• •

•

•

•

•

•

•

•

•

•

•

•

Maintenance solutions for conveyors

•

Belt Tracking Rollers, Ceradisc, Skirt Sealing

•

• •

•

•

•

•

•

•

IOT condition monitoring for bulk handling belt conveyors

Gearboxes for conveyors driving applications •

•

•

•

•

We don't actually manufacture these, we offer testing services

• •

•

•

•

•

•

Complete transfer chutes and deflectors

• •

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

Closed Conveyor Systems (EBS) & Continuous Haulage (CHS)

•

Belt Cleaners, Belt Trackers, Conveyor Safety Products, Conveyor Covers, Metal Detectors, Magnetic Separators, Screening Products, Materials Flow Solutions, Loading Chutes, Conveyor Accessories, Belting & Repair Products, Magnetic Wear, Repair & Seal Products

Diverter ploughs, cleaners, air knives,

• • •

•

•

•

•

•

• •

•

•

•

•

•

•

•

•

•

•

•

•

•

Australian Bulk Handling Review: September/October 2021 І 27

CONVEYORS

Evaluating the indentation rolling resistance performance of conveyor belt covers As conveying distances and belt speeds continue to increase, greater emphasis is being placed on energy efficiency in belt conveyor design. As a result, TUNRA Bulk Solids has seen an increasing number of inquiries which focus on the testing and analysis of higher energy-efficiency conveyor belts and idlers.

RESEARCH BY HAGER AND Hintz [1] has concluded that up to approximately 60 per cent of energy consumption in long distance conveying systems is due to the indentation of the belt cover passing over the idlers.

Considerable research efforts have been placed in reducing such energy losses, including the development of low rolling resistance compounds by conveyor manufacturers [2].

Indentation rolling resistance is affected by several factors, including the idler roll diameter, belt loading, belt cover thickness and the viscoelastic properties of the bottom cover. Such properties are also dependent on operating conditions including temperature, belt speed and belt load, which imposes challenges when trying to predict the indentation losses of a conveying system.

Predicting indentation rolling resistance

There are two general approaches for determining the indentation rolling resistance losses of a conveying system, these are the large sample and small sample methods. The large sample method uses a full sample of belt in a

Figure 3: Small sample preparation from complete belt section.

Figure 1: Large Sample Indentation Rolling Resistance rig at TUNRA Bulk Solids, the University of Newcastle

closed loop, including the carcass, carry and pulley covers, whereas the small sample method uses a small sample of the pulley (bottom) cover of the belt only.

Large sample indentation loss method There are different test setups associated with the large sample method, one such test method is described in German standard DIN 22123 [3] and another is included in Australian standard, AS 1334.13:2017 [4]. For these test methods, the indentation rolling resistance is measured directly by an instrumented idler roll, as a function of normal load, for a specific pulley cover compound, idler roller diameter, pulley cover thickness, temperature and belt speed [5]. The indentation rolling resistance is typically reported per unit belt width to enable comparison between compound types and to allow designers to scale results for the actual belt width to be installed on a system. The Conveyor Equipment Manufacturers Association (CEMA) [6] includes a method for utilising the large sample measurements to calculate the indentation losses when the required idler diameters and belt cover thicknesses of a system are different from what was tested.

28 І Australian Bulk Handling Review: September/October 2021

The large sample testing facility located at TUNRA Bulk Solids, shown in Figure 1, can carry out indentation rolling resistance testing according to both DIN 22123 and AS 1334.13:2017, as well as having the ability to measure conveyor belt flexure resistance [5, 7].

It accommodates samples between 400 millimetres to 600 millimetres wide and 29,000 millimetres long (full spliced length).

Small Sample Indentation Loss Method CEMA 7th Edition [6] has included a small sample indentation loss model with constants for several example rubber cover compounds that can be applied to the CEMA model for initial design feasibility studies. For the small sample method, the dynamic physical properties of a rubber sample piece, with a thickness of up to three millimetres, are measured over a range of temperatures, strain amplitudes and frequencies. The dynamic physical properties, being the viscoelastic properties of the belt conveyor cover rubber, are obtained by applying an oscillating mechanical deformation to a sample and measuring the resultant stress. The stress response of a viscoelastic

actual force is kept constant throughout testing when using the tension clamp.

Samples to perform dynamic mechanical analysis can be purpose made, where a thin sheet of the rubber compound is cured in a mould.

Alternatively, test samples can be prepared from the bottom cover of full sections of conveyor belt, where a segment of the bottom cover is passed through a belt splitter to obtain a sample with a near constant thickness. An example of the steps taken to prepare a sample from a full section (carcass, carry and pulley covers) is shown in Figure 3.

Figure 2: Small Samples mounted in (a) tension clamp and (b) dual cantilever clamp

material will be out-of-phase with the

of a conveyor belt due to the idler rolls

applied strain by an angle δ. From the results of these tests, the elastic modulus E’, loss modulus E” and phase angle δ can be calculated. Specialised Dynamic Mechanical Analysis (DMA) equipment is utilised to obtain these properties which are then applied to theoretical models to calculate the indentation rolling resistance per idler set as a function of loading, temperature, belt speed, cover thickness and belt width. The DMA testing equipment used by TUNRA Bulk Solids is a TA Instruments RSA-G2 Solids Analyser.

Figure 2 shows sample test pieces set up in the RSA-G2 Solids Analyser using the tension and dual cantilever clamps.

The deformation rate of the bottom cover

normally ranges from 50 to 1000 Hz, which is outside the RSA-G2 testable range. To determine the viscoelastic properties at these equivalent frequencies, time–temperature superposition principles (TTS) are employed [2], which involves holding the temperature and strain amplitude constant while varying the frequency, from which E’, E” and tan δ master curves are derived. The temperature and frequency can be related through the Williams Landel Ferry (WLF) transfer equation [8]. The RSA-G2 has an axial force adjustment feature that senses volumetric changes in a sample from changes in temperature and adjusts the clamp position accordingly to ensure the

Case study: Overview:

Table 1 Testing Specifications Item

Test specifications

Clamp type

Tension

Frequency range

0.1 to 10 Hz

Temperature range

-40° to +50°C (in 5°C increments)

Strain amplitude

2%

A recent project completed by TUNRA Bulk Solids involved an independent assessment of the indentation rolling resistance properties of a series of Fenner Dunlop belt samples.

Dynamic Mechanical Analysis (DMA) testing was conducted on conveyor belt bottom cover rubber samples to

CONVEYOR

determine their viscoelastic properties.

Specifications for the DMA testing are presented in Table 1.

The viscoelastic material properties were applied to the QC-N model from Qiu and Chai [9]. The QC-N model was selected to predict the indentation rolling resistance for this project due to previous research showing that this model performs favourably when compared to other commonly applied rolling resistance prediction models [10].

The predicted indentation losses of the pulley cover were then compared to measurements conducted on the large sample indentation rolling resistance test facility, shown in Figure 1, as a function of belt load for a belt speed of 4 m/s and belt temperatures of 20°C and 40°C. Details of the large sample belt conveying system are presented in Table 2. These are also the parameters used in the analytical model to calculate the indentation losses for the samples under the operating conditions described for a direct comparison of results between the small and large sample methods selected.

The apparent bottom cover thickness was used for calculations, which is equal to the bottom cover thickness plus half the cord diameter [11].

Results: The indentation rolling resistance is presented for one of the small sample rubber compounds evaluated with the QC-N loss model against the large sample measurements, as a function of belt load.

The pulley cover of the large belt sample tested was made with the same rubber compound tested as the small sample.

The relative indentation rolling resistance is shown in Figure 4 for a belt operating temperature of 20°C and Figure 5 for a belt operating temperature of 40°C. Furthermore, the indentation loss was calculated for the large sample conveying system in Figure 1 using the small sample method described in CEMA 7th edition, for the Default rubber and Type 1 (low rolling resistance) rubber for reference. The relative indentation losses have been in included in Figure 4 and Figure 5.

Figure 4: Relative indentation rolling resistance at 20°C.

Figure 5: Relative indentation rolling resistance at 40°C.

experimental measurements and the small sample prediction model for the same pulley cover compound. This indicates that the QC-N model performs relatively well at predicting indentation rolling resistance for the compound analysed.

The results also demonstrate that the indentation rolling resistance performance of the tested pulley cover compound is lower than that of the example rubbers presented in CEMA 7th edition. This shows that selecting a general rubber type, instead of evaluating the actual compound to be used for a conveying system, may result in inaccuracies when determining design values. This disparity may become particularly significant for long overland conveyor systems where indentation losses make up a large percentage of the total losses for a system. Since any calculation inaccuracies are compounded at each idler set, the cost of insufficient detail during design may result in costly over or under design of the system.

References: 1. Hager, M. and A. Hintz, The Energy-Saving Design of Belts for Long Conveyor Systems. Bulk Solids Handling, 1993. 13(4): p. 749-758.

2. O’Shea, J.I., et al., The influence of viscoelastic property measurements on the predicted rolling resistance of belt conveyors. Journal of Applied

Discussion and Conclusion: The results presented show a good comparison between the large sample

Polymer Science, 2014. 131(18).

3. DIN 22123: Conveyor belts - Indentation rolling resistances of conveyor belts related to beltwidth -

30 І Australian Bulk Handling Review: September/October 2021

Requirements, testing. 2012, German Institute for Standardisation (Deutsches Institut für Normung) (DIN).

4. A S 1334.13:2017: Methods of testing conveyor and elevator belting Determination of indentation rolling resistance of conveyor belting. 2017, Standards Australia.

5. W heeler, C., et al., How to Design Energy Efficient Belt Conveyors, in Bulk Solids Handling. 2020: bulk-online.com.

6. C onveyor Equipment Manufacturers Association (CEMA) 7th Edition. 2014, Belt Conveyors for Bulk Materials.

7. M unzenberger, P. and C. Wheeler, Laboratory measurement of the indentation rolling resistance of conveyor belts. Measurement, 2016. 94: p.

909-918.

8. W illiams, M.L., R.F. Landel, and J.D. Ferry, The Temperature Dependence of Relaxation Mechanisms in Amorphous Polymers and Other Glass-forming Liquids. Journal of the American Chemical Society, 1955. 77(14): p. 3701-3707.

9. Q iu, X. and C. Chai, Estimation of Energy Loss in Conveyor Systems due to Idler Indentation.

Journal of Energy Engineering-asce, 2011. 137: p.

36-43.

10. O ’Shea, J.I., Mechanical and dielectric relaxation studies of conveyor belt compounds to determine indentation rolling resistance properties. 2015, The University of Newcastle, Callaghan.

11. W heeler, C.A. and P.J. Munzenberger, A pseudo 3D analysis of the indentation rolling resistance problem, in BELTCON 15 Conference. BELTCON 15. 2009, IMHC: Johannesburg, South Africa.

Safeguard your operations and reduce your environmental footprint with DYNA Engineering’s HDPE Conveyor Guards.

S AFE S MART

S USTAINABLE DYNA Engineering’s HDPE Conveyor Guards are leading the way towards a more environmentally sustainable future by being manufactured with 100% reycled and recyclable HDPE plastic.

Our “X” design increases the guard’s strength and our design is simple, intuitive and robust.

DYNA Engineering doesn’t compromise on your safety.

Reduce your material handling risks and increase safety for your personnel with our guards, which are up to 40% lighter than conventional steel guards.

Our HDPE Conveyor Guards will reduce your overall maintence cost as they do not require painting, rust or corrode.

1800 801 558 www.dynaeng.com.au

CONVEYORS

Conveyor idler noise Noise generated by conveyor idlers can have a negative impact on people living nearby. Aspec Engineering’s Paul Munzenberger explains how this noise can be measured and what can affect it.

CONVEYOR SYSTEMS are used widely in mining and material handling applications to efficiently move large amounts of bulk materials from one location or process to another.

Often, conveyors are operating near populated areas where their noise emissions need to be managed. This is especially true at ports which are often sited near to densely populated residential suburbs. Conveyor noise is generated by bulk material impacts at loading points, conveyor drive units, vibrating conveyor structures, ancillary equipment and from conveyor idlers. In the past, conveyor idler noise was evaluated with experiments that measured the self-noise produced by a conveyor idler.

More recently, conveyor idler noise experiments have changed to measure their operating-noise which is created by the interaction of the conveyor belt rolling on the conveyor idler as shown in Figure 1. These later experiments have shown that the surface finish of a conveyor idler is the main contributor to conveyor idler noise generation.

Conveyor idler self-noise It is widely thought that the primary source of conveyor idler noise is the idler itself. This noise source is called conveyor

Figure 2: Conveyor idler operatingnoise test idler and belt arrangement.

idler self-noise. Testing for conveyor idler self-noise is conducted by using a sound meter to measure the noise produced by one or more conveyor idlers mounted in a frame while they are rotating at operating speeds. The test idlers are driven with a light – low tension – belt that is powered by a small drive motor. The motor is positioned in a sound insulated cabinet so that the noise it makes is not added to the conveyor idler noise. Conveyor idlers that undergo a self-noise test are usually in brand new condition and do not produce any adverse noises. The typical noise level of a conveyor idler self-noise test is about 45 – 50 decibels A (dBA), which is less than the noise level of a normal conversation.

The conveyor idler self-noise test is of limited usefulness in determining conveyor noise production due to the low levels of noise that are measured by the test.

However, this is not to say that conveyor

Figure 1: Conveyor idlers supporting a conveyor belt.

32 І Australian Bulk Handling Review: September/October 2021

idler self-noise can always be ignored as they are able to produce prominent humming or high pitch squealing noises which are both self-noise generators.

Idlers that produce a lot of self-noise have generally been in service for some time and have developed some fault that will cause them to be quickly replaced in areas where noise minimisation is important.

The noise produced in the later stages of an idler’s life will bear no resemblance to the results from its self-noise test.

Conveyor idler operating noise The main source of conveyor idler noise production is through its interaction with the conveyor belt it supports rather than the self-noise it generates. Any useful test that measures conveyor idler noise levels will involve a tensioned conveyor belt rotating the test idlers under a reasonable load. This alternative test is known as a conveyor idler operating-noise test as it measures the noise of an operating idler that is in contact with a conveyor belt.

The conveyor idler operating-noise test has the advantage of measuring the louder idler and belt interaction noise while also measuring the much quieter self-noise of the rotating idlers. The surface of a new conveyor idler’s shell is typically rougher than a used idler’s surface and the idler’s operating-noise will quieten down as its shell surface is used and polished smooth by the conveyor belt rather than get louder as with conveyor idler self-noise.

A conveyor idler operating-noise test

is conducted by first tensioning a flat, light weight and clean fabric conveyor belt between a drive pully and a tension pully.

Five conveyor idlers, that are wider than the belt, are arranged with three above one of the strands and two below the same strand, as shown in Figure 2. The two groups of idlers are brought together such that the belt forms a zig-zag path between them with about 10° of wrap on the middle three idlers. Noise levels are measured, while the conveyor belt is rotating the conveyor idlers, over a range of velocities which includes the intended operating speed. The typical noise level of an operating-noise test is between 70dBA and 100dBA. A useful way to compare measurements between different test equipment is to calibrate the equipment with a set of machined steel conveyor idlers and make tension adjustments until a sound pressure level of 74dBA is recorded for a belt speed of four metres per second. Calibration would be done

for each different conveyor idler size.

The calibration noise level is arbitrary, and the test is only useful for the relative comparison of operating-noise between conveyor idler types. More research is required to determine a correlation between the conveyor idler operatingnoise test and an actual conveyor.

Conveyor idler shell material and noise production In a general order of increasing operatingnoise, mass-produced idler shells are made from polymers, aluminium, and steel.

The actual shell material seems to have little bearing on the relative noise output of a conveyor idler with noise production

Figure 3: TIR and MIS relative conveyor idler radius measurements.

GLOBAL LEADERS IN CONVEYOR IDLER MANUFACTURING & SUPPLY

Through extensive research and innovation RKM have developed a comprehensive product range that provides our clients with suitable rollers for any application.

RKM heavy duty pressed steel housing 70% weld penetration

Quality

Primary Heavy duty nylon outer protective shield combined with inner labyrinth

Innovation

Secondary Water and dust proof RR outer flinger plus RR inner seals.

Multi labyrinth male/female pre-greased seal

Manufacturing Performance

Mild and stainless steel stepped, straight or hollow shafts Date of manufacture stamped on shaft ends

RKM specified ERW conveyor tube Back seal High performance sealed for life ZZ C3, RKM, SKF, NTN deep groove ball bearing

www.rkmrollers.com.au

Circlip Bearing Retention

Min. 3mm continuous fillet weld to AS 1554.1 or AWSD1.1

RKM’s Engineered Product Solutions

CONVEYORS

The research corresponded well with mass produced conveyor idlers and showed that only the MIS properties of a conveyor idler shell influenced operating-noise. However, TIR cannot be ignored because the TIR measurement gives an indication of idler balance and idlers with large TIR measurements, and correspondingly poor balance, will vibrate a conveyor structure loose over time and cause vibration related noises especially from corrugated steel conveyor enclosures.

Figure 4: Conveyor idler operatingnoise for increasing TIR.

being more closely related to the finishing processes of each material. Mass produced polymer conveyor idlers are relatively quiet, due to their shell nearly always being machined during their manufacture.

change in radius of the conveyor idler is measured for every six degrees of rotation at the idler’s ends and centre. The TIR is reported as the difference between the highest and lowest readings and the

Conclusion

Mass-produced steel conveyor idlers have a weld seam on their shell which increases their noise output and mass-produced aluminium conveyor idlers are extruded which gives them a noise output between polymer and steel conveyors due to the lack of a weld seam on one hand and the lack of machining on the other.

The addition of polymer endcaps to metallic shell materials will reduce the operating-noise as this removes the weld distortion at each end of the shell.

Machining of any conveyor idler is the best option to reduce conveyor idler operating-noise and it has been found that finely machined steel idlers are the quietest overall. Quieter conveyor idlers are possible, but they require fine machining, balancing and assembly to a standard that is uneconomical for mass production and the effort will yield an expensive conveyor idler that is only a few tenths of a decibel quieter than a machined steel conveyor idler.

MIS is the largest difference between consecutive readings as shown in the graph presented in Figure 3.

Operating-noise research was conducted by Munzenberger and Wheeler for which a set of perfectly round but eccentric conveyor idlers were produced along with another set of perfectly round and concentric conveyor idlers that possessed a small flat machined along the shell to mimic the presence of a weld seam. The former group was designed to have a large TIR and practically zero MIS and the second set was designed to have practically zero TIR but a large MIS. Noise levels were measured for several sets of each group of conveyor idlers with progressively worse measurements.

It was found that operating-noise did not increase with increasing eccentricity – Figure 4 – and that operating-noise increased with increasing MIS – Figure 5.

contribution of the conveyor idlers. The conveyor idlers are not the noisiest item on a conveyor, but their noise output is present along the entire length of the conveyor. When considering the noise production of conveyor idlers, it is safe to ignore the self-noise of the idler, but it is important to consider its operating-noise. When specifying the low-noise idler type, not only should the conveyor idler’s TIR and MIS measurements be specified, the shell material, construction method and construction accuracy should also be considered alongside the idler’s finishing process and balancing.

Ultimately, however, conveyor idlers are cheap mass produced and disposable items and the effort that is expended to produce low noise versions needs to be balanced with the level of noise reduction that is required.

Shell measurements The forging hints that it is the surface quality of the conveyor idler’s shell that is responsible for much of the operatingnoise. There are two tests commonly used to assess idler shell quality: total indicated runout (TIR) and maximum indicated slope (MIS). The TIR test gives a measure of the eccentricity of the idler shell and the MIS test gives a measure that is roughly proportional to the radial surface velocity of a conveyor idler as it rotates. For MIR and TIR tests, the

Figure 5: Conveyor idler operatingnoise for increasing MIS.

34 І Australian Bulk Handling Review: September/October 2021

When designing a conveyor system for a noise sensitive area or retrofitting a conveyor system to reduce its noise levels, it is important to consider the

Resetting the life cycle clock Combining over 50 years of service to the Australian mineral processing industry with a state-of-the-art production facility, we are uniquely placed to reset your machine’s life cycle clock. Using our cutting edge equipment and OEM know-how, we can give your machines a new lease of life, all backed by our exclusive factory warranty.

That’s great news for both your bottom line and the environment.

Don’t take our word for it see for yourself what sets us apart from generalist equipment repairers

www.schenckprocess.com.au

CONVEYORS

Optimising your conveyor’s backbone

Idler are the main backbone of the whole system but are often ignored. Thomas Greaves, General Manager for DYNA Engineering, explains how to get the best results from idlers.

IDLER SETS ARE USED TO SUPPORT the belt along the conveyor structure and are available in a variety of designs including inline trough, offset trough, return, trough trainer, return trainer, transition, and many more.

Usually speaking, an idler set comprises a steel idler frame and the cylindrical-shaped roller(s) fitted within it. Idler sets are probably one of the least routinely inspected components of many a conveying system yet are the main backbone of the whole system.

When operating at peak efficiency they will add many more hours of troublefree running than a poorly maintained set. So, they have the potential not only to enormously improve conveying productivity but also avoid unscheduled shutdowns which often affect an entire project’s operation.

Idler frames There are a wide variety of idler frames

available. The four most common types each have benefits. Some of these benefits include impact absorption, support for the carry and return sides of the belt or maintaining correct tracking of the belt.

Idler rollers Idler rollers, sometimes known as conveyor rollers or rollers, are cylindricalshaped bars that run along and underneath a conveyor belt. There are many different types of idler rollers with varying functions.

Usually, idler rollers aid in the supporting of weight and impact of the material being transported along the belt.

But they’re also invaluable in the smooth, continuous movement of the material along the belt.

Troughing idlers guide the transportation of objects on a conveyor.

Idler rollers running beneath a conveyor belt form a trough that keeps loose material from falling off the belt.

36 І Australian Bulk Handling Review: September/October 2021

Tracking rollers are a very useful idler to keep the conveyor belt operating within the conveyor system limits and specifications. Newer designs, such as the DYNA-TRAC Tracking-Roller, are self-aligning and adjusting maintaining the belt tracking down the centre of the conveyor system.

Quality assured DYNA Engineering conveyor rollers are manufactured from high quality ERW tube, precision pressed bearing housings, quality double sealed bearings, and labyrinth seals. The company’s quality assurance systems include testing of rolling resistance, run-out and dynamic balance to ensure every roller meets their high-quality standards. Conveyor rollers are manufactured in accordance with strict quality controls and use the latest manufacturing techniques and equipment to achieve superior life, reduced rolling resistance, and ultimately delivering lower

operating costs.

Thomas Greaves, General Manager for DYNA Engineering, said even a regular simple inspection of idler frames and rollers at each scheduled maintenance check could potentially avoid catastrophic consequences down the track.

“It doesn’t take long to conduct a simple visual and even taking a quick shot from a phone for further checking of anything which looks a bit suspicious,” he says.

“If an unscheduled conveyor stoppage occurs the entire project could be negatively impacted. The simple carrying out of a visual check can prevent this and the vast amount of money needed to repair and get the system, or the entire project up and running again”.

“When you think about it, it’s such a quick and easy thing to do and usually the replacement or repair costs for Idler frames and/or rollers are not that excessive. So, ‘just do it’ would be the mantra we’d recommend to all

Idler sets are fitted at different sections under both the carry and return belts, depending on differing requirements of their use.

conveying maintenance people, whatever site they may be on”.

Dyna’s idler frames are fabricated in the company’s Western Australian workshops. They are available in a range of finishes, including standard painted, optional galvanised, or can be finished to

any project requirement.

Greaves says they can even be painted pink if requested.

“We are market leaders for conveyor rollers and frames, we set very high design standards and do not compromise on quality,” he says.

Need a Hand With Your Material Storage Design? +61 8 9277 3303 \ info-australia@jenike.com \ jenike.com

Your Source for: • • • • • •

Storage systems: engineered to ensure reliable, consistent material flow Processing vessels: developed to purge resin volatiles or act as a dryer Feeders: optimized screw and belt feeders that maintain reliable flow Stockpiles: designed to maximize gravity reclaim and avoid ratholing Pneumatic conveyors: engineered for flow, prevention of wear & attrition Peer reviews: a review of proposed system design from material flow basis

55 YEARS

Innovating, modelling, and designing.

We have been your bulk material solution provider from concept to commercialisation for 55 years.

Solids \ Powders \ Conveying \ Processing \ Storage

CONVEYORS

Oli Vibrators bust transfer chute buildup Buildup in a transfer chute can lead to expensive complications. Removing it manually can be slow and unsafe, which is why Oli Vibrators helps remove it with the touch of a button.

WHENEVER CERTAIN MATERIALS move through a transfer chute and hit a wear plate, they can begin to build up.

It can happen to any product that becomes glutinous or homogenises with moisture. Mark Thompson, Director at Oli Vibrators, says coal can be one of the worst offenders.

“It could be material like clay, or if you’re working on a tunnelling project and hit a water vein, that mud and hard rock could start creating problems,” he says.

Material buildup in a transfer chute will start to reduce the capacity of the transfer chute and can stifle or even block the conveyor, completely stopping the process. The resultant mess would then need to be manually dug out.

Buildup can also lead to spillage,

is expensive and can cause damage to components.

Thompson says an easy fix to this problem is to install industrial vibrators on the transfer chute.

“Oli Vibrators performs a detailed analysis of the chute, looking at the points where a vibrator can be fitted and where it will have the least amount of fatigue impact,” he says.

“We want to avoid any fatigue on the structure itself while also finding the best area of influence in the buildup zone. After we’ve done that, we can provide clients with advice on installations and analyse resources they have available.”

By installing a vibrator on the chute, the company can get rid of the buildup with the touch of a button. Depending on the duty cycle, the vibrators can be turned

Buildup can also lead to spillage, is expensive and can cause damage to components.

38 І Australian Bulk Handling Review: September/October 2021

on at specific points or run through a programmable logic controller.

Internet of Things-enabled technologies can be integrated into the system, with level indicators and capacitance sensors able to detect a buildup and turn on the vibrator to automatically remove it.

This removes the need for operators to place themselves in precarious positions, often at height and in enclosed, dusty, and wet areas, to remove buildups themselves.

Thompson says, fitting a vibrator also protects the assets themselves, as often the buildup is removed by striking the chute with a sledgehammer or heavy object.

“Every time you hit a chute with a hammer, it creates a potential hang-up point for the material. I’ve seen chutes with ‘hammer rash’ where people have been constantly belting it. Seeing a bin or hopper with hammer rash is a sure sign there is an area in the process that needs addressing,” he says.

“Not only is using a hammer dangerous because you’re swinging around a large hammer at heights, but it is also bad for your bones and hearing.

Using vibrators helps preserve both the structure and the person.”

Thompson adds that most designers aim to build chutes that don’t need vibration, and it is often a method of last resort or frustration. However, he adds that once they’re installed, the buildup problems disappear quick with very little effort.

Oli Vibrators can install the systems on almost any transfer point. The company has installed vibrators on chutes for cocoa in a chocolate factory and at quarries handling 500 tonnes of limestone per hour. Chutes that use ceramic lining are often unsuitable, as it could damage the

Striking a chute with a hammer to remove a blockage can make the problem worse.

bond between the chute and lining so our flow aid range may be more appropriate.

The company has operated in Australia for more than two decades and has built up expertise in providing the right tools for the job. Thompson says Oli Vibrators’ staff are knowledgeable about its products and know how to apply them to all kinds of situations.

“Our staff have worked with materials handling for years and we have enough case studies under our belt where we can use previous experiences to find new solutions,” he says.

“What sets us apart are the high-quality materials and precision engineering that goes into making each of the vibrators. The company is based in Italy and imports its products from

work in conjunction with the process and are energy efficient.”

Oli Vibrator’s mission statement

replacement or repair of the product.

Thompson says fast support is critical to many of its customers, who

overseas where they must meet rigorous Australian and International quality assurance standards.

“They’re also virtually maintenance free and easily replaced. Once fitted, they go about their business based on the operation. They can be programmed to

is ‘when you need it, where you need it’. To deliver on that, the Australian business keeps plenty of spares on hand if required and can call upon all 22 of the global company’s trading subsidiaries.

Each product also comes with a two-year warranty, which includes full

have a limited timeframe to work in.

“That’s why we offer around the clock support. If a process fails in a food manufacturer’s production line in the middle of the night, we can get a solution sent over to get everything working again by morning,” he says.

• materials handling • asset life extension • infrastructure ASPEC Engineering provides high quality technical engineering support to mines and ports

www.aspec.com.au

CONVEYORS

Delivering Aquila’s overland conveyor Last year, Fenner Dunlop ACE was contracted to deliver an overland conveyor system for Anglo American’s Aquila project. ABHR speaks to Brendon Harms, Regional Manager of ACE Queensland to find out how the project has progressed.

THE BOWEN BASIN COALFIELD is home to dozens of coal projects, producing almost 100 per cent of Queensland’s coking coal and 60 per cent of its thermal coal.

One such project is Anglo American’s Aquila – an underground hard coking coal mine near Middlemount.

The company selected Fenner Dunlop ACE to design, supply and install the 2.6-kilometre-long ACV002 Overland Conveyor, along with four drives, a transformer, loop take-up, elevated gantry sections, overland

structure, and belting.

The contract, awarded in 2020, also included the mechanical and electrical installation, belt installation and commissioning.

Brendon Harms, Regional Manager of ACE QLD, says the team has completed the design and supply stages of the project and is now halfway through the installation.

“The process has been a major success. We’ve been able to handle the complete project entirely in-house, which has given us both a lot of control and responsibility,” he says.

Ongoing maintenance will be offered through the Mackay and Emerald branches, providing belt works and servicing over the life of the project.

The overland conveyor will run from the underground to the surface and then move up to the stockpile.

40 І Australian Bulk Handling Review: September/October 2021

“For example, between the design and supply stages, we’ve been able to complete works in parallel to expedite the process.”

The overland conveyor will run from the underground to the surface and then move up to the stockpile.

Often, the product will be put onto a stockpile outside the mine, but because the project will make use of an existing stockpile and wash plant, the conveyor will help connect the infrastructure together.

Included within the design are several custom components, such as a horizontal curve in the conveyor and an elevated stacker to load onto the stockpile.

The conveyor is a crucial piece of infrastructure for the mine, as it is the only means of extracting the coal. To ensure it operates effectively, Fenner Dunlop ACE has been through a series of stringent design reviews and quality assessments.

Harms says the complete turnkey philosophy gives Fenner the ability to handle any issue, whether they be schedule related, quality related or design related.

“Accountability is a key part of Fenner Dunlop ACE,” he says. “We take pride in building something right the first time, every time.”

“It also means that when we supply our own original equipment, the installation and maintenance team have direct access to the manuals, installation procedures and support at the touch of a button. Using multiple companies for something like this adds an additional step when it comes to logistics and communications.

“There’s also the personal

monitoring and thickness testing through Fenner’s iBelt technologies, to measure the ongoing performance of the conveyor. In addition, it will supply ongoing maintenance and associated project warranties.

Fenner Dunlop ACE’s maintenance and installation teams are made from the same pool of talent, which means future support will have intricate understanding of how the overland conveyor operates.

Ongoing maintenance will be offered through the Mackay and Emerald branches, providing belt works and servicing over the life of the project.

The company’s ACE team in Mackay has expanded significantly over the past seven years to ensure it can handle

means that there are no arguments between multiple suppliers - we simply

satisfaction our employees can get from seeing a project go from a design drawing to a conveyor. It adds to the sense of ownership and pride we have for delivering the project.”

As part of the project, the company will provide online condition

large projects such as this.

Harms says Fenner Dunlop’s head to tail approach gives the client the comfort of knowing that all the components will work together as they should.

“If something does go wrong, it

provide the most effective support possible to solve any problems as early as possible,” he says.

The conveyors are due to be commissioned near the end of 2021, with the project expected to be finalised in 2022.

To ensure the conveyor operates effectively, Fenner Dunlop ACE has been through a series of stringent design reviews and quality assessments.

CONVEYORS

Fixing the flaws of poorly designed transfer points Poorly designed conveyor transfer points can lead to spillage, tracking issues and expensive clean up. Kinder Australia aims to overhaul these dusty hazards with its Essential Seal suite.

TRANSFER POINTS PLAY A VITAL role in conveying systems, allowing material to pass from one conveyor to another. However, if they are poorly designed, it can lead to significant issues.

Spillage is a common side effect of poor transfer point design. Material flows onto the wrong part of the belt below, spilling onto the surrounding components or escaping the system entirely. This can lead to build-up on the rollers and belt, which can then lead to issues with carryback.

Carryback can cause all sorts of problems in a materials handling operation. As material sticks to componentry not designed for it, different forces can lead to tracking difficulties, which can even lead to structural or belt damage.

These problems can be expensive to fix, and if the root problem isn’t addressed, can continue to build up.

Charles Pratt, Operations Manager at Kinder Australia, says spillage also creates some of the worst jobs in the bulk

handling industry.

“Cleaning up spilt material is a terrible task. Nobody wants to do it and it means your employees are doing dull, tedious busywork,” he says.

“Spillage creates dust, meaning if it falls to the ground the environment can become hazardous.

“Clean-up costs are also expensive, with specialised contractors costing producers potentially thousands of dollars an hour.”

Supressing dust particles around high pressure transfer points is one of Kinder Australia’s specialties. The company provides several products as part of its Essential Seal package to help improve transfer points, making an operation significantly safer and cleaner.

For example, the K-Sure Belt Support System solves belt sag problems where there are too few idlers installed at the

Spillage is a common side effect of poor transfer point design.

42 І Australian Bulk Handling Review: September/October 2021

loading point. The K-Dynamic Impact Belt Support System also improves material containment at the conveyor’s transfer point using anti-vibration mounts.

The K-Containment Seal enhances the success of the outer seal by reducing the high internal pressure experienced inside the chute and protects the vulnerable chute edges from damage. In addition, the K-AllShelter Capotex Conveyor Belt Covers offer a protective barrier, aiding airborne dust reduction, and protection from extreme environmental elements.

Pratt says the company is always looking to expand and improve its offering, which is why it keeps an eye on global innovations.

“The Airscrape contactless conveyor belt skirting system is something I have personally been watching for the past three to four years,” he says.

“After seeing its success elsewhere, Dust can be hazardous to workers and the environment.

I got in touch with the designer to help grow the technology in Australia.”

The Airscrape is suspended over the conveyor belt and acts as a side seal. Its unique diagonal arrangement of hardened fins, called lamellae, lead air from the outside into the middle of the belt, creating a suction effect. The material moving together with the belt support increases the suction effect, which keeps dust particles in the conveyor section.

In addition, the lamellae lead coarse materials pushing outwards back to the middle of the belt, significantly minimise spillage.

Pratt says the AirScrape uses an innovative and patented design that reduces material spillage and dust formation particularly at critical

“We’ve had incredible feedback from customers. Some have said it looks too good to be true, which was my initial reaction when I saw it a few years ago.

It’s like when the first maglev trains were revealed, how could a train without wheels work?”

Kinder has put together several videos and case studies to help people see proof of the Aiscrape in action. The company plans to include the Airscrape in its Essential Seal suite of products to expand its use across Australia as much as possible.

Pratt says a big part of how Kinder operates is bringing the best technology to market.

“Australia has innovated some amazing things, but to limit ourselves to

transfer points.

“Additionally, due to the skirting and sealing system’s ability to hover freely above the conveyor belt, skirt friction and belt damage can be eliminated, service life of other conveyor components can also be extended,” he says.

be reliant on just our own innovations would be silly,” he says.

“There’s a mix of Kinder innovated products and globally sourced products in our offering now. We have an open mind and are always looking to find the very best solutions for our customers.”

The Airscrape is suspended over the conveyor belt and acts as a side seal.

Comprehensive Processing & Handling Solutions

ADELAIDE MELBOURNE

P A N FEEDER S

A P R O N FEEDER S

G R IZ Z LY FEEDER S

P A N FEEDER S

A P R O N FEEDER S

G R IZ Z LY FEEDER S

BRISBANE PERTH

1300 400 M PS

DARWIN SYDNEY

sales@mpsaus.com.au www.mpsaus.com.au

CONVEYORS

Conveyor belt cleaner tension: A key to optimal performance Conveyor belt cleaner design has evolved over the past 50 years. Martin Engineering’s Todd Swindermann explains how expectations and development has changed over time.

THE MOST COMMON MECHANICAL belt cleaner designs present a blade or brush at various angles to the belt.

Depending on the cleaner type and materials of construction, they can approach the belt at either a positive, negative or zero rake. Industry has gravitated toward mechanical cleaners and tensioners because they are simple and economical.

Regardless of the basic cleaning approach, maintaining the optimum range of contact pressure will result in the best balance between cleaning performance, cleaning element wear, belt wear and power requirements.

An automated tensioner.

Basic approaches to tensioning There are two basic approaches to applying tension to the belt cleaner: linear and rotary. The blade’s angle of approach to the belt often dictates whether a linear or rotary tensioner is applied. The stored energy that creates the tensioning force most often comes from gravity, springs, or actuators. The Conveyor Equipment Manufacturers Association (CEMA) defines the cleaning positions as primary, secondary, and tertiary. Most belt cleaners mounted in the primary position use a rotary style tensioner, while most belt cleaners mounted in the secondary or tertiary positions use linear style tensioners.

Linear tensioners Linear tensioners are most often applied where the compensation for wear is required in small increments, such as with hard metal-tipped cleaners located in the secondary cleaning position or with brush cleaners. The basic tensioner design approach is typically a carriage that constrains the support frame but allows linear movement along a guide or guides

roughly perpendicular to the belt surface, with the support frame and blade design providing the cleaning angle. Some designs incorporate a relief ability for impact by splices or belt defects.

Linear tensioners are simple in design, can be engineered to one setting for full blade wear, allow access windows to be easily incorporated within the mounting footprint, can accommodate actuator deflection scales for accurate adjustment of cleaning pressure, and deliver the ability to adjust for uneven mounting positions or asymmetrical blade wear.

However, the tensioner footprint can be large, restricting options for ideal belt cleaner installation. There must also be access to the far side for adjustment, the guide mechanisms are subject to fouling from dust and corrosion and changing from bottom adjustment to top adjustment or providing for adjustment from one side complicates the tensioner design.

Rotary tensioners Rotary tensioners utilising an actuator are principally designed using a lever

44 І Australian Bulk Handling Review: September/October 2021

arm or an elastomeric element that is concentric with the belt cleaner support shaft. They apply a blade-to-belt contact surface determined by the actuating force and linkage geometry. The energy source delivers a force to the lever arm which rotates the shaft and forces the belt cleaner blades against the belt surface.

Rotary designs tend to be compact and, in most cases, the actuators can be mounted at any orientation, which provides options for installing the belt cleaner in the optimum position.

Counterweight tensioner At one time the most common rotary tensioner was a counterweighted lever arm, with its position adjusted to apply the design cleaning force to a blade or blades that contact the belt. A counterweight can be mounted on one end of the shaft or both. Usually, the initial installation would have the arm angle set so that at the midpoint of the blade wear the arm would be horizontal, thus roughly averaging the design cleaning force over the life of the blade.

The primary advantage of the counterweight design is that it is selfadjusting by gravity. The disadvantages of the counterweight design are the lack of damping which allows the blade and the weight to bounce when struck by a splice, strongly adhered material, or a defect in the belt. The unexpected movement of the counterweight can represent a safety hazard and uncontrolled bouncing can result in belt top cover damage. The counterweight tensioner takes a significant amount of space and if the counterweight arm cannot be mounted horizontally there is a reduction in the force applied to the blade, because the effective lever arm is shortened.

Rotary lever arm and actuator tensioners Rotary adjustment of the belt cleaning blade can be accomplished in several ways. The support frame is almost always in a fixed location but free to rotate. The required tensioning forces can be applied by many types of actuators, such as springs, fluid cylinders, electric actuators or from torque stored in an elastomeric element. Rotary tensioners are often used with elastomeric blades, where the change in blade height and thickness as it wears is significant.

The advantages of rotary tensioners are a compact design, a single tensioner mounted on one side of the conveyor can often be used for a range of blade styles and belt widths. They can be designed to minimise the number of times the tensioner has to be adjusted during the life of the blade and many types of actuators can be used.

There can be a safety hazard if the support frame is mounted too far from the pulley and the cleaner pulls through.

Other disadvantages include the mounting location of the axis of rotation, which is critical for proper blade cleaning angle.

The constant force output by some actuators can result in a wide variance in cleaning pressure and blade life over time and when a tensioner is required on both ends of the support frame, it is often difficult to access the drive side of the conveyor for mounting and adjustment.

Other factors The importance of proper installation

should not be overlooked for the proper performance of the belt cleaner. Slight variations in the location of the support frame relative to the belt can cause significant issues with the effectiveness of the blades and can result in support frame bending. Most manufacturers provide detailed instructions for the location of the support frames and tensioners, which must be followed for optimal function.

To be effective, belt cleaners should be frequently inspected and maintained.

In practice, the design of the conveyor structure and location of the drive and other equipment makes service difficult.

Consideration in the design stage for easy access and ergonomic location of the cleaners for inspection and service will pay dividends in reducing carryback, maintenance time and potential exposure to injuries.

To maximise blade effectiveness and minimise rapid wear, the recommended adjustment protocols should be followed.

Studies have shown that there is a critical cleaning pressure range for various types of cleaners and blade types. These studies demonstrate that over-tensioning the belt cleaner does not necessarily improve the cleaning effect, but often results in increased belt and blade wear as well as higher power consumption.

Blade style cleaning angles.

reports with certainty when a blade is nearing the end of its useful life, delivering a greater return on cleaner investment.

Replacement orders can be scheduled for just-in-time delivery, reducing the need to stock parts inventory, and installation can be scheduled for planned downtime

As technology continues to advance, suppliers are beginning to integrate an increasing level of functionality in belt cleaner designs. One such innovation is a belt cleaner position indicator that can monitor the blade and estimate remaining service life based on the current hourly wear rate. Able to retrofit directly to existing mainframes, the device can send a notification to maintenance personnel or service contractors when a cleaner requires re-tensioning or replacement.

Inspection and service time is reduced, as maintenance personnel no longer need to physically view the cleaner to determine the tension or wear status. It also reduces the time workers need to spend near the

instead of on an emergency basis.

Taking the technology a step further is another patent-pending device that combines the position indicator with an automated tensioner. This novel powered assembly incorporates sensors that constantly monitor blade pressure and adjust its position to maintain optimal cleaning tension. Maintenance personnel no longer need to visit each cleaner and manually re-tension. Instead, the tasks are performed automatically, reducing maintenance time while maximising the usable area of every cleaner.

Analytics provide an unprecedented view and understanding of belt cleaner performance, with real-time data available remotely via a specially designed app.

While manufacturers continue to improve belt cleaner effectiveness, it has become clear that there is no single or ideal solution for belt cleaning and tensioner selection. Safety of personnel and the belt itself is an important consideration when selecting a tensioner.

Ease of inspection and maintenance is critical for belt cleaner effectiveness, so the tensioner must allow for quick and safe service.

The system should be selected based on life cycle cost and not just the initial price. The investment for effective belt

moving conveyor, helping to minimise the potential for accidents. By relying on data – not human judgement – to maintain the appropriate tension for optimal cleaning performance and monitor blade wear, the indicator maximises service life and

cleaning is justifiable on direct cost reduction (cleanup costs), extended component life (often 25 per cent to 40 per cent) and reduced exposure to injuries, which is directly related to reduced cleanup frequency.

The future of cleaner tensioning

Australian Bulk Handling Review: September/October 2021 І 45

CONVEYORS

Different horses for conveyor courses Conveying materials from one spot to another comes in many shapes and sizes. ABHR speaks with Victor Stiller, General Manager at Kotzur Toowoomba, about how the company provides a range of solutions.

THERE ARE SEVERAL DIFFERENT types of conveyor systems available for bulk handlers, each with different capabilities depending on parameters such as the required capacity, material to be conveyed, distance, height, and budget.

On top of that, conveying equipment often relies on specific equipment like valves, slide gates, spouts, and transitions to link everything together.

Victor Stiller, Kotzur Toowoomba General Manager, says it’s a case of different horses for different courses.

“Kotzur’s design team will scope out the project to get the best outcome for the client,” he says.

Kotzur can manufacture a wide range of conveyor systems, including drag conveyors, bucket elevators, screw

Kotzur design, manufacture, install and maintain bucket elevators from very low capacities up to units that achieve 1500 tonnes per hour.

Drag conveyors are effectively a chain in a loop with paddles attached, encased in an enclosed trough.

conveyors, belt conveyors, road hoppers and silo unloaders.

Drag conveyors Drag conveyors are effectively a chain in a loop with paddles attached, encased in an enclosed trough. The chain is driven by a sprocket on the discharge end of the conveyor. Product is dropped in one end, and the chain ‘drags’ the product along the conveyor and it discharges out the other end.

Stiller says there are a few variants available within two main types, enmasse drag conveyors and high-flight drag conveyors.

“En-masse drag conveyors are typically horizontal or shallow angles.

They can carry product many times deeper than the height of the flights and as such are quite an efficient machine,” he says.

“High-flight drag conveyors are better suited to inclines that can be quite steep. They have flights that are at least as high as the required product depth which prevents the product rolling back at steep angles.

“Kotzur manufacture both types of drags in capacities from 10 tonnes per hour (and less) up to 1000 tonnes per hour. Higher conveyor capacities than this can be developed as a bespoke solution.”

The materials used for these conveyors is typically galvanised steel,

46 І Australian Bulk Handling Review: September/October 2021

but they can also be made from stainless or painted steel if required. Chains and flights are often manufactured from different materials as well, depending on the application, as some products can be quite aggressive on plain steel.

En-masse drag conveyors have the benefit of being relatively efficient and due to their fully enclosed nature, keep the elements away from the material and stop dust escaping. They are also relatively gentle on the conveyed material itself, when compared with a screw conveyor. In most applications, a drag conveyor will have low maintenance requirements.

Stiller says another benefit is the fact they can have multiple inlets and outlets, with each outlet controlled by a slide gate.

“Having multiple outlets can pose issues with a drag conveyor if product carries past the desired outlet as it can build-up at the ‘head’ end of the conveyor and cause damage,” he says.

“Kotzur have a specially designed ‘carryover head’ for this application that deals with this by returning any carried over product back around. A typical application for a drag with multiple outlets and one inlet would be across the top of several silos for filling. A similar drag conveyor on the bottom of the same silos would have multiple inlets and one outlet.”

Bucket elevators Kotzur also designs and manufactures bucket elevators, which are the primary means of conveying product vertically. A belt (or chain in some cases) is looped around two pulleys: one at the ‘head’ or top of the elevator, the other at the ‘tail’, or bottom. The belt has a series of buckets attached to it which carry the product up the elevator over the head pulley and as they go over, they either throw the product out of a discharge chute on a high-speed system or simply tip it out on a low-speed system. The belt and bucket system as well as the pulleys are all contained within a fully enclosed casing.

Stiller says that while the the main principle of a bucket elevator is a relatively simple concept, there are many variations in casing material, bucket shape and material, belt material, size, belt speed, capacity, and height.

“The properties of the material being conveyed, and the desired throughput capacity and height are the main determining factors when determining the specifics of the system,” he says.

“The calculation of belt speed, bucket size and shape, pulley size and other parameters needs to be done very accurately, particularly on a high speed or centrifugal discharge elevator as they are all inter-related and impact on the efficiency of the machine.”

Kotzur design, manufacture, install and maintain bucket elevators from very low capacities up to units that achieve 1500 tonnes per hour in a high duty cycle, 24/7 commercial operation.

Casing materials include galvanized steel, stainless steel, or painted fabricated steel. Buckets can be made from different materials as well including stainless steel, mild steel, nylon or HDPE. There is often a high structural component to the elevators, given their size and height, requiring extensive engineering.

There is typically a head platform at the top of the elevator for maintenance purposes and an access system to reach it.

Stiller says all of Kotzur’s equipment is designed and manufactured in Australia.

“While we have ‘standard’ models based primarily on capacity and some other parameters, these standard products are configurable to an extent to give optimum flexibility to the client,” he says.

“These can then be automated to different levels, from a basic ‘manual’ system to a system which allows a single operator to control a large and complex storage facility.”

Bucket elevators can have many variations in casing material, bucket shape and material, belt material, size, belt speed, capacity, and height.

MAXXFLOW HTC

FLOW MEASUREMENT FOR DRY BULK SOLIDS • Powder • Dust • Granules

• High Temperature • High Pressure

M-SENSE 3 ONLINE MOISTURE & PROCESS TEMPERATURE MEASUREMENT WITH FLOW DETECTION • • • • • • •

Powder Dust Granules Bins Feeders Conveyers Mixers

NEW

AIRSAFE

CONTINUOUS AMBIENT AIR DUST MONITORING • • • • • •

Powder Dust Granules High Temperature High Pressure Non Contact

DETECTION OF SILICA DUST

NEW

SWR ENGINEERING

BINTECH SYSTEMS DRY SOLID FLOW SOLUTIONS

1300 363 163 sales@bintech.com.au www.bintech.com.au

DUST CONTROL

Defeating dust with simple physics When they were first introduced, DSH Systems’ loading hoppers were called magic. ABHR speaks with Ian Walton, Chief Executive Officer at the company, to find out how they really work.

AS MATERIAL FALLS FROM A loading hopper into a truck or vessel, it’s highly likely to create significant amounts of dust.

This dust poses several risks. In grain applications, the dust can be explosive. When working with sand and minerals it can lead to diseases like silicosis when inhaled, and when working near waterways, such as a port, it can be a potential source of pollution.

Ian Walton, Chief Executive Officer at DSH Systems says the business created an innovative solution when trying to solve a dust problem at a fertiliser plant.

“In 2004, Trevor Schwass – the company’s founder – was working as a contractor when he prototyped a technology that could solve the issue,” Walton says.

“After completing the contract, he cashed in his pension and started the business to share the technology with the world.”

The DSH hopper uses a central plug, fixed in position with a gap between itself and the hopper. When the hopper

is loaded with material, springs extend and begin to control material flow so that a solid column of material exits.

Air is removed from the material and dust entrained in the column so that minimal dust is released and little to no segregation occurs.

Fine, moist, non-granular, and poor flowing materials, such as cement, milk powder, coal, or flour, don’t work with the system. The material feed rate also needs to be fairly consistent, as wild fluctuation cause instability in the material column.

Walton says in the early days, customers would call it the “magic bucket” or claim the evidence was photo trickery.

“The only wizardry is its innovative design, which combined experience in bulk handling with physics,” he says.

Global growth The system has been used across the world to great success. Initially, Australia was one of the company’s starting markets, due to its proximity to New Zealand. However, the technology

When the hopper is loaded with material, springs control material flow so that a solid column of material exits.

48 І Australian Bulk Handling Review: September/October 2021

has spread far across the globe, to the point where Australia makes up less than 10 per cent of the business’s total turnover.

Walton says this growth has been largely driven by its customers, who have been impressed by the results.

In Vietnam, one of the country’s leading ports for bulk commodities was suffering from significant amounts of grain dust generated near active grain loading and transfer operations.

Incoming grain from ships and soybean meal produced at a nearby crushing facility was creating huge amounts of dust as they moved through the system, leading to low visibility and a potential explosive environment.

All the airborne dust was also considered waste, as it was not included in the final load. To solve the problem, the port invested in a DSH system installed at five key grain transfer locations, including inside a warehouse, at a barge loading dock and at three truck loading locations.

Each hopper is installed under a feed point where it can be suspended above the discharging target and kept at operating level. At the point of loading, the DSH system concentrated the discharge into a solid column, without the use of electric power or internal moving parts.

The installation of the hoppers resulted in a dramatic decrease in airborne dust during loading at these locations. In addition, loading processes were faster and cleaner, maintenance costs were reduced and the removal of air from the products increased storage capacity.

The port’s Environment, Health and Safety director, John Zhao, said investing in a healthier working environment was one of the ways the company showed care for the community and its employees.

“Controlling dust risks isn’t just about ensuring that workers are wearing the right PPE for the job,” he says. “The best solution is always to eliminate or capture as much dust as possible at the source.”

The hoppers have also been used for non-standard applications and sizes.

Walton says DSH works closely with its customers to find the right solution for specific operations.

“For example, in Brazil one of our customers approached us and asked if we could design a much larger version of the hopper for them,” he says.

“This is a common request.

Often when people see how effective the regular hoppers are, they want to see them used for bigger,

The system can drop material from significant heights with little dust emissions.

1800 689 433

critical applications.

“Now, instead of loading 100 tonnes an hour, we have installed systems that are capable of loading 3000 tonnes an hour.”

The company is now working to

further integrate the systems to be Industry 4.0 compatible. Following a request from a French customer, DSH has developed a hopper that interfaces with a programmable logic controller, allowing it to work alongside automated equipment.

Loading trucks with dry material can create hazardous dusts, which the DSH system minimises.

Your Storage & Conveying Specialists

DUST CONTROL

Don’t let dust issues get the better of your process With operations handling massive quantities of bulk materials every day, the dust generated can become a serious health hazard to mining personnel and the surrounding community. Corin Holmes, Operations Manager at Jenike and Johansen, explains how operations can reduce these risks.

TRENDS IN MATERIAL CORIN HOLMES Corin Holmes is the Operations Manager for Jenike & Johanson Pty Ltd in Perth.

He received his Master’s degree from The University of Greenwich and is passionate about applying the science of bulk solids handling to help people and organisations succeed, especially those in the resources sector.

Turbulence is also generated when the air-entrained particle stream strikes a surface/object reducing the stream velocity. As a result, the air stream and fine particles that are carried along

handling over the last decade have exacerbated the problem of dust generation. Much of the materials handled is transported at much higher speeds than in the past, increasing the potential for entrained dust. Improper design of materials handling equipment can further exacerbate the issues associated with dust contamination with hazards affecting operations, health of workers and surrounding communities, and in some cases even cause fire or explosions.

Dust generation requires three elements analogous to a framework such as that of a ‘fire triangle’ (see Figure 1): • Presence of fine particles capable of being entrained in air present in either the feed material or generated during handling (such as attrition/degradation of particles).

• Amenability of the fine particles to be entrained (low particle to particle cohesion).

• Elutriation – a process of separating bulk solid particles based on size, shape, and density.

The primary mechanism of dust

with it, are forced to escape. This mechanism can form billowing clouds of dust particles that can travel hundreds of meters from the source.

Figure 1: Dust generation triangle.

generation is the dispersion of fine material particles into turbulent air streams that develop with a falling material stream (see Figure 2). Some of the kinetic energy of the falling material stream is transferred from the material to air in the stream and, to a lesser degree, the surrounding air that enters the stream at the boundaries.

It is quite common to see of dust generation during bulk solids transfer.

At the boundary between the material stream and surrounding air, some of the fine particles can be stripped from the material stream due to frictional drag and then carried away (this mechanism is depicted in Figure 3).

Figure 2: Dust generation during stockpile formation.

Figure 3: Fine particles stripped from the stream.

50 І Australian Bulk Handling Review: September/October 2021

DUST CONTROL METHODS DUST COLLECTION The primary method used to control dust is by aspiration (the process of removing dust from the air) while the bulk solid is being handled.

This is usually accomplished by the dust collection system which takes the dusty air and conveys it to a filtration system for dust separation and collection. Once the dust is collected the particulates are often recirculated back into the material handling system.

There are four key components of a dust collection system: the filter, duct work, pickup hoods, and the air mover. Many vendors provide excellent components that do the job; however, the key is to get the components to work as a cohesive unit to provide effective dust collection.

An example dust collection system is shown in Figure 4. Dust generated at a point source is pulled into pickup hoods and the air flow through the hoods is be controlled by either blast gates (common) or by duct sizing (less common, but more effective). The duct work (called branching and

Figure 4: Illustration of components for a dust collection system [1]

trunk lines) is routed through the facility, often changing directions multiple times, and likely increasing in diameter along the length. The trunk of the ducting terminates at the filter/collector where the particles are separated from the air stream. The filter operates by either an inertial or a physical barrier (cloth ‘sock’ or fabric, sintered metal) as a means of retaining the particles while the air leaves the collector.

The heart of the dust collection system

is the air mover/filter combination. The symbiotic relationship between the two components is important. If the filter becomes clogged with dust, the fan performance will likely be reduced causing major system problems.

When it comes to dust collection design one should consider a ‘system design’ engineering approach versus a “component selection” method. There are several tips to ensure a well operated system [2]: • Tip #1 – Ensure sufficient conveying velocity. Sufficient conveying velocity is required to pick up the dust from the pickup hoods and transport the material to the filter/collector for separation from the air stream. If you can’t effectively convey the dust, then you will not collect the dust, other than in the horizontal duct work.

• Tip #2 – implement balance-by-design.

The balance by design method is the preferred method to ensure adequate conveying velocity in each portion of the system. With balance by design, the duct

size and layout are engineered to balance the branches, pickups, and trunk layouts based on static pressure loss through each section. If each branch has a similar static pressure loss, then the air flow, and thus velocity, through each branch will be equal. This avoids the need to use blast gates or orifice plates to manually adjust air flow per branch.

•T ip #3 – Select the right air mover.

The selection of an appropriate air mover is straight forward once the system resistance is determined [3].

Fans and positive displacement (PD) rotary blowers are typically used to provide the suction force for the dust collection system. It is important when designing the dust collection system that anticipation of maximum solids loading, some build-up, and other factors increasing system resistance are considered for fan and motor selection.

Keep in mind that as the system resistance goes up in a dust collection operation, the fan will not generate as much air flow. As a result, particle

Air-cushion BELT CONVEYOR Both belt and product are carried on a cushion of air

MONEY SAVING FEATURES: • • • • • • •

Low power consumption • Reliability Low wear and tear • Low maintenance High capacity • Light weight belt Steep angles of inclination • High belt speeds Dust tight • True belt tracking Complete settling of materials on belt Simple conversion from open to closed conveyor

CONTACT US FOR MORE INFORMATION

Aerobelt Australia Pty Ltd Ph: 02 4631 2919 | Mob: 0419 279 566 | Fax: 02 4631 2915 info@aerobelt.com.au | aerobelt.com.au

DUST CONTROL

velocity of the receiving belt.

By following these techniques, the amount of dust generated at a transfer point can be reduced by orders of magnitude, if not eliminated completely. [7]

CAUTION – DUST EXPLOSION HAZARD Figure 5: Methods of dust suppression .

Figure 5: Methods of dust suppression .

settlement (called saltation when in a horizontal pipe or duct section) leading to build-up and/or complete plugging may occur. Many fans will lose over 30 per cent of their air flow when the system resistance doubles. Usually with a dust collection system a variable

dust will have to be either disposed of (incurring additional cost) or installation of a recycle system to feed material back into the process.

speed motor is not necessary, though it can be ‘nice to have’.

• Tip #4 – Avoid plugging. Dust collection system plugging can manifest in many forms, such as in the duct, hopper, or filter. The root causes can be plentiful: poor duct layout (too many bends and/or multiple bends in a row), over-feeding the line, air leaks, build-up in piping, and hopper/ receiver plugging. There are many instances where the conveying velocity was correctly selected and the fan and motor operated as required, but the dust did not convey effectively through the duct.

• Tip #5 – Don’t ignore the separator.

Separator performance can make or break the dust collection system. A properly performing separator will efficiently filter the particles from the air stream, clean itself, discharge the solids into a hopper, and allow proper air flow through its media, thereby maintaining conveying velocities in the system and stable fan operation. Poor separator performance can allow particle bypass through the filter, clogging and plugging, and substantially reduced air flow rendering dust pickup and conveying moot.

dust is by adding moisture or chemical dust suppressants (salts, emulsions, surfactants, polymers, lime sprays, foams, see Figure 5) to the bulk solid before or during handling [4,5,6]. Although this may be a helpful method for minimizing dust, adding moisture, or suppression agents often result in a more cohesive material causing flow issues such as unreliable discharge from storage bins or build-up/plugging of transfer chutes.

While the use of dust collection systems and suppression may be effective methods for minimizing dusting, modifying, or replacing improperly designed equipment (such as a transfer chute) should be considered as it may result in significant reductions in dust generation.

Collecting the dust generated during handling can be expensive given the potential large capital cost of dust collection equipment (dust collectors, filters, or special dust collecting housings). Furthermore, the collected

• Keep impact angles small.

• Keep the velocity through the chute as near constant as possible.

• Make sure that the particles leaving the chute are traveling in the direction of and close to, or greater than, the

DUST SUPPRESSION An alternate approach to reduce

DESIGN FOR DUST MITIGATION IN TRANSFERS Dust is often created in a transfer chute when the flowing material entrains air.

A beneficial tactic is to design transfer chutes to prevent dust from becoming airborne in the first place. Myriad techniques could be used to accomplish this task, including: • Keep the material in contact with the chute surface.

• Concentrate the material stream.

52 І Australian Bulk Handling Review: September/October 2021

In a recent survey of nearly 250 engineers working in industrial plants that handle, store and process bulk solids, only 15 per cent indicated that they knew the explosivity potential of their materials.

Nearly 70 per cent of all dusts are flammable, meaning they can explode as a dust cloud. Consider this in the context that around 50 per cent of dust explosions occur in dust collectors. [8] Many dusts can burn rapidly either in a flash fire or an explosion scenario. Though most people are aware of the hazards of flammable gases and liquids, some may not know the hazards of combustible dusts handled in storage or dust collection equipment [9]. A dust explosion requires five key ingredients (see Figure 6): • combustible dust (e.g., sugar, plastic, wood, metals, and most carboncontaining dusts) • oxidant (oxygen is present in air in most process areas) • ignition source (static discharge, hot surfaces, sparks) • dispersion (dust can be readily emitted from numerous sources) • confinement (dust collector, silo, dryer, mill/grinder) Even if confinement is eliminated from the explosion pentagon, a dangerous flash fire deflagration event can still occur causing damage to property, injuries, and possibly loss of life. This further highlights the need for a proper dust collection system. Without it, dust can accumulate

Figure 6: Dust Explosion pentagram.

on horizontal surfaces creating opportunity for a hazardous flash fire event. Excellent guidance for preventing and protecting against combustible dust hazards are presented in several NFPA standards [10]. (Author’s note: Do not ignore protecting the dust collector as it provides the perfect conditions for a deflagration. There are many methods to protect the equipment and process through explosion containment, isolation, suppression, and venting. NFPA 69 provides excellent guidance for each of these approaches).

Dust control is one of the most pervasive issues relating to materials handling especially at mine sites and processing plants. With operations handling massive quantities of fine bulk

question? Jenike & Johanson has developed the science of bulk solids flow and specialises in applying it to solving the most challenging bulk solids handling problems. So why not put them to the test with your question?

The harder, the better.

materials every day the dust generated can become a serious health and safety hazard. Applying proper design techniques can dramatically mitigate dust generation and the associated risks.

Do you have a bulk solids handling

Disease Control and Prevention, National Institute for Occupational Safety and Health, Spokane, Washington; 2012.

4 Bader, Charles D.: Controlling Dust, Erosion Control, July/August 1997.

5 Zador, Andrew: Methods to Prevent

References 1 Wikipedia: https://en.wikipedia.org/wiki/ Dust_collector 2 Maynard, Eric, ““Six Key Considerations for Proper Dust Collection System Design”, Powder & Bulk Engineering magazine, Volume 32, No. 10, October 2018, pp. 22-33 3 Dust Control Handbook for Industrial Minerals Mining and Processing; RI 9689/ Report of Investigations, Department of Health and Human Services, Centers for

Environmental Pollution at Large Bulk Material Handling Terminals, Bulk Solids Handling, September 1993.

6 Baeyens, J., Smolders, K., Dumont, Ph.: Stockpile Dust Emission and Suppression, Bulk Solids Handling, May/June 2001.

7 Petro, G.J.: Chute Design for Effective Pet Cokes Handling, Solids Fuel Handling, 1996.

8 Eckhoff, R.K., “Dust Explosions in the Process Industries,” 2nd edition, Elsevier, 1997.

9 Maynard, E., “What is a Dust Hazards Analysis (DHA) and why do I have to worry about it?” Australian Bulk Handling Review, May/June 2018.

10 www.nfpa.org/652, NFPA 652, 2016 edition: Standard on the fundamentals of combustible dust.

Note: The advice here is of a general nature. Specific solutions are very sensitive to their circumstances; therefore, you should consult with a specialist in the area before proceeding.

THE WORLDWIDE LEADER IN VIBRATION TECHNOLOGY

INDUSTRIAL VIBRATORS

Designed for industrial sectors OLI is the world’s top selling manufacturer of electric and pneumatic vibrators.

The high level of customer service, guaranteed by 18 trading subsidiaries worldwide, and long-lasting and performing products make us always ahead.

Our vibrators are designed for industrial applications in all sectors, from the most extreme environments such as quarries, mines and foundries to the food and pharmaceutical.

OLI Vibrators Pty Ltd. 7 Jellico Drive, Scoresby Vic 3179, Australia - Phone: +61 3 9764 9988 - Mail: info@olivibrators.com.au - www.olivibrators.com.au

CONDITION MONITORING

talk

Condition monitoring of belt conveyors Steve Davis explains the ins and outs of conveyor condition monitoring and how it can be deployed to save operators time and money.

STEVE DAVIS In his regular BULKtalk column, Steve Davis considers the basics of bulk handling that sites often struggle with.

Steve has worked in bulk handling for 30 years, for both resource companies and professional engineering firms, in Australia, South Africa, the Middle East and Canada.

His experience encompasses such commodities as iron ore, coal, potash, phosphates, petcoke, sulphur, sands and grain.

A ONE-KILOMETRE-LONG conveyor will have 4000 plus components: belt, pulleys, bearings, idlers, drives, cleaners, chutes etc. These components all wear out at different rates.

Damage is common and component life becomes difficult to predict. What options are there for getting the best life from your conveyors?

Firstly, what should we be looking at on typical conveyors to maximise uptime and component life?

Belting and all aspects of the conveyor that cause damage to the belt, as this is the most expensive to replace: belt cost, labour cost and lost opportunity. In the worst case, a failed belt or splice will lead to potentially fatal outcomes as the belt and load run away and the take up falls. Belt tracking causes, and there are many, are usually the result of other

It is difficult to assess internal components visually, so often operators rely on noise, visible bearing collapse, and seizure to identify failure or near onset failure.

54 І Australian Bulk Handling Review: September/October 2021

condition issues. The result can be extreme belt damage, spillage, and structure damage.

Pulley condition, as poor

cause belt cover damage and can cause belt tracking. Idlers that are buried in spillage will fail early as the bearing seals are penetrated.

lagging and entrapped material create uneven stress distribution across the belt and lead to carcass and splice failure and bottom cover wear, sometimes puncturing through the belt. Seized or collapsed pulley bearings, excessive shell wear, loose connections have many impacts and can lead to serious collateral damage. Allowing pulley bearings to run with incorrect lubrication or buried in spillage encourages early failure.

Loading zone problems will cause belt tracking through off centre loading, incorrect skirts set up and adjustment can wear through the carry cover or allow spillage and dust escape. Worn or maladjusted belt cleaner systems allow excess carry back and may damage splices.

Ploughs and safety attachments, as they prevent rocks getting trapped in the pulley nip point and damaging the belt and pulley; even worse if they come loose and run into the pulley.

Seized idlers can fail producing the ‘potato peeler’ and ‘pizza cutter’ effects, cutting through

Spillage increases idler drag and energy consumption and is a cause of belt tracking. Spillage can initiate corrosion leading to shell failure.

Check drive components and maintain. Brakes and holdbacks are safety devices and must be functional. Couplings may need lubrication. Gearboxes need oil. Check the drive set up, as incorrect fluid coupling fill or variable frequency drive set up can limit starting ability or increase acceleration time such that dangerous problems results.

Guards should be visually assessed for condition and attachment. Any part of the guard that allows access to a danger zone or is a danger from corrosion or damage, snags or sharp edges must be fixed.

the bottom cover and can heat up and cause fires as they grind to a halt. Watch for idlers that have come out of the frame, as they can damage and injure. Buildup of carry back on idlers will

for visible damage or unusual noise, temperature, operation.

This option is viable for smaller installations where manpower with sufficient knowledge to determine condition is available.

What do we do to monitor condition of our conveyors?

There is the run it until it breaks and then repair philosophy. The only condition monitoring is by inspection. Failure or wear is determined through walking the machine and checking

Component life is maximised, but the downside is the random nature of failure causing outages and downtime. There is high potential for consequential damage, like allowing pulley lagging to deteriorate to where belt damage results, or high carry back because cleaners are not repaired. Component replacement is mostly planned based on an estimate of life. However, this likely sees some early unplanned failures and many components replaced earlier than necessary.

More common is an approach that combines inspection with a range of basic condition monitoring techniques. Typically, the installation will include belt tracking sensors, as belt replacement due to damage has the highest cost in materials, labour,

allow operators to inspect or stop conveyors before there is a catastrophic failure and limit resulting damage and outage. Where there are progressive changes in condition it makes sense to have multi-stage monitoring, with a warning before a stoppage for noncritical aspects. For example, a warning when gearbox oil temperature is higher than expected so that condition can be monitored and assessed, with automatic shutdown when the temperature exceeds the highest permissible level. Planned maintenance is still used.

More advanced operations will spend a little more on prevention and include manual or on-line vibration monitoring, monitoring of lubricant flows, pressures and feeds, lubricant sample analysis.

There are several methods for checking

trend monitoring can indicate potential

and lost opportunity. In addition, we might monitor pulley and motor bearing temperatures, gearbox and hydraulic oil temperatures, lubricant reservoir levels, with an alarm or trip when a set point is exceeded. These indicators

belt rips in use, but all require a rip to occur before indication. Some will regularly manually measure residual belt cover and pulley lagging thickness and visually inspect wear liners in chutes.

These require shutdown. Motor power

problems from bearings in pulleys and idlers, poorly adjusted skirts and other causes of belt drag. Trending of data is then used to predict condition, likely time to failure and to schedule shutdowns and change out.

A ‘portable’ installation can assess and record the condition of a belt over several cycles, detecting broken or damaged cords.

We’re reaching new heights in engineering.

The sky’s the limit.

With decades of experience in the field, Kinder Australia supply superior products designed in-house and manufactured from high quality materials to improve your conveyor efficiency.

https://kinder.com.au

CONDITION MONITORING

Ploughs and safety attachments prevent rocks getting trapped in the pulley nip point and damaging the belt.

What could we do to better monitor condition of our conveyors?

Our industry has developed many remote condition monitoring systems that give online feedback and warning. Others are being developed, and the Australian industry has many good suppliers.

Most of these systems provide detailed software for analysing output.

We can monitor belt condition online via several methods. The most economical method requires a ‘portable’ installation that will assess and record the condition of a belt over several cycles. The analysis is repeated at regular intervals and builds a trend of the condition. This is useful for installations with multiple conveyors.

Types available include magnetic and X-ray and they can identify missing, broken, and damaged cords, corroded cords, misaligned or kinked cords, changes in splice condition and belt cover thickness.

Other systems are available for permanent installation, and with continuous monitoring. These can identify all above issues and belt wander, cover condition, belt rip initiation and fabric carcass condition. The cost of these systems is easily amortised on longer belts against the savings from better understanding and life obtained if used correctly. Major belt manufacturers have their own systems and there are several independent suppliers.

Shock pulse monitoring is available for a more sophisticated analysis over vibration analysis for slow speed bearings as installed on pulleys. Bearing manufacturers will advise the best lubrication regime for these bearings based on operating conditions, and the application can be monitored on-line

to confirm. For intermittently operated conveyors we have systems that can be programmed to supply grease only when required.

We have remote wear liner monitoring systems that allow wear trends to be developed without shutting down. These allow for maximised wear liner life and the possibility of implementing liner regimes to even out wear. How much quicker would it be to know which liners to change before shutting down and hosing out? Could high wear panels be made rotable?

Idlers are a major problem for assessment. Our one-kilometre-long conveyor has approximately 4000 idlers in carry and return frames. It is difficult to assess internal components visually and we usually rely on noise, visible bearing collapse and seizure to identify failure or near onset failure. It is sometimes difficult to hear unusual noises over background even with headphones and microphone. It is often near impossible to see centre roll idlers and sometimes there is only access to one side of the conveyor.

Lighting is often poor. What can we do?

We have systems that can identify changes in idler baseline condition information through the installation of a fibre-optic cable on the conveyor stringers. This will generally indicate the gradual deterioration of idlers in a localised area such that inspection and change can be targeted at the next opportunity. It will indicate the change

Build-up of carry back on idlers will cause belt cover damage and can cause belt tracking.

56 І Australian Bulk Handling Review: September/October 2021

that comes with catastrophic failure also.

We have systems that monitor each idler frame and identify changes in baseline conditions for assessment. The sensors can be retrofitted to existing idler frames.

We have systems that are installed inside individual idler rolls and provide roll by roll condition on a continuous basis, and include data such as vibration, shell condition, bearing temperature and speed. The monitors are built into idlers during manufacture and supplied as complete units.

Many of the technologies available to monitor conveyors are now available with wireless connection, avoiding cabling and multiple I/O connections. I have recently seen a system that is fully plug and play, with ability to receive signals from hundreds of locations by piggybacking into a single gateway and that completes all integration and assessment in the cloud before directing output back to the plant control system.

Is it a value proposition to invest in remote condition monitoring? This will be system specific and depends on financial calculation such as net present value (NPV). NPV does not consider the potential to remove people from the monitoring equation, thereby reducing contact with conveyors and risk of injury. NPV also does not generally consider the possibility to anticipate and manage failure to best financial and operating advantage.

Nelson Silos Lime/Cement Silos Factory to Site

Up to 300 tonne Capacity Transportable.

Rochester Vic to Newman WA For all your bulk storage problems, please call Nelson Silos, Rochester Victoria Toll Free on:

1800 801 966 Head Office T: 03 5484 1577 F: 03 5484 1593 New South Wales Email

T: 02 6862 3688

Website

www.nelsonsilos.com.au

info@nelsonsilos.com.au

We have technical consultants based in Melbourne, Sydney, Brisbane and Auckland (NZ)

Australia’s largest manufacturer of transportable silos.

2021

AUSTRALIAN MINING PROSPECT AWARDS

E L A S N O W O N S R G E T I M NIN E E R I K P M S ’ C E A I H I T T TRAL OR RY F LS ST S S U A ARD ERA NDU AW D MIN ING I au .

S om N c S .

A CE s d r O a w PR a ct pr Pre

p os

ted se n

by

e

on Sp

so r

s

PULLEYS

A deeper understanding of conveyor pulley friction Despite significant research, there is still much more to learn. Experts from the University of Newcastle and Elastotec investigate the emerging issues around pulley friction, the complexity of the issue, and the failures that may result.

BELT CONVEYORS FORM A CRITICAL part of the materials handling process and have established themselves as the chosen technology for transporting bulk materials at high tonnages over long distances.

As the scale of new mining operations continues to increase, this has resulted in an unprecedented demand on these systems to convey material further, faster, and up greater elevation.

Significant improvements in the tensile strength of belts and the refinement of dynamic models to assess the transient tensions under starting and stopping conditions have allowed for reduced safety factors, greater transport distance and lift, as well as faster belt speeds. Despite the considerable amount of research that made these achievements possible, much room for improvement remains in understanding the effectiveness of drive systems to transmit the large amounts of power now required by these systems.

The drive system forms a critical component of any belt conveyor, tasked with transmitting the force required to start and stop the conveyor, as well as maintain a constant operating

Figure 1: Euler drive friction model.

velocity. This force, known as the effective belt tension, is traditionally transmitted through a drive pulley, to the pulley lagging (if installed), to the rubber bottom cover of the conveyor belt, and eventually to the reinforcing carcass (steel cord or fabric) within the conveyor belt. The effectiveness of this transmission is ultimately defined within a frictional contact between the conveyor belt and the drive pulley surface.

Review of current design methods Drive system design relies on the respective belt tension either side of the drive pulley, denoting T1 as the tight side tension, and T2 as the slack side tension. The difference between these two represents the effective tension (Te) outlined above, and the force required to be transmitted through the drive system to allow the belt to operate. The design method is well understood, based on Euler’s classic ‘rope friction’ model defined below.

T1 =eμθ T2 Where, µ = the coefficient of friction between the belt and the pulley surface, and

Physical damage and delamination on a high-tension bend pulley began to show after three months.

θ = the angle of wrap of the belt around the pulley The simplicity of this model naturally has corresponding limitations, the majority of which are also understood within industry. The assumption that the friction is fully developed around the arc of contact relates only to rigid body contact and means that each point of contact around the pulley surface exhibits an equal coefficient of friction.

This is not possible for a viscoelastic drive mechanism in shear. The gradual increase in belt tension around the drive pulley, coupled with the varying normal force (see Figure 1) results in a varying degree of viscoelastic slip within the contact, and therefore a varying coefficient of friction. For viscoelastic surfaces, friction may only truly reach is maximum kinetic value when the belt is slipping, or on the verge of slipping.

Design standards such as ISO5048 and DIN22101 compensate for this by utilising

Australian Bulk Handling Review: September/October 2021 І 59

PULLEYS

Naturally, this indentation is load and slip dependent, with Tiwari predicting a coefficient of friction in a planar contact region (flat surfaces) of around 0.4 – 0.8 depending on rate of slip between the two surfaces.

When the ceramic protrusions begin to be contaminated by rubber shavings from belt wear, this coefficient increases to as high as 1.5 under a Figure 2: Tension around the drive pulley for a 210° arc of contact. contact pressure of 0.62 MPa. a conservative coefficient of friction of Coefficients of friction in excess of 1 have up to 0.45, depending on lagging type also been measured experimentally by and degree of contamination, while Robinson et al [3] for both ceramic and traditional values of kinetic friction may polyurethane lagging under a curved be as high as 0.8 for ceramic lagging [1]. contact area. It is well known that these coefficients will vary with age and wear

associated with wing idler pressure, idler junction wear, idler skew, or any combination resulting in an uneven cover thickness. When a worn steel cord belt travels around a pulley, the arc length of each steel cord will vary across the belt width, resulting in localised stresses on the cords and splices. This stress is subsequently transmitted to the lagging, and its bonding with the pulley.

The resulting cord stresses are not directly proportional to the length of arc as one may expect. To maintain total load across the belt, cords adjacent to those with reduced load bearing compensate for the reduction in load capacity of the worn sections, leading to a peak ‘switch’ stress at the wear junction. This stress is subsequently transmitted to

of both the pulley lagging and belt cover.

the pulley lagging, and ultimately the bonding method, potentially leading to failures on lagged drive or high-tension bend pulleys, as well as reduced life expectancy of belt splices.

Research conducted by Overland Conveyor and Elastotec [4] has developed a model to predict the increase in stress due to unequal load sharing between cords, based on Hedgepeth’s model for cable load sharing [5]. An example from this research is given below, describing the load sharing between cords for an 1800-millimetre wide belt, consisting of 120 cords across its width. A parabolic wear pattern 10-millimetres deep at its centre is removed from the middle third of the belt, to simulate carry-side wear.

As can be seen from this research, the switch stress is located at the wear junction point, and in this instance, is approximately double that of the uniform cord tension.

Actual friction behaviour around the pulley arc

Several researchers have investigated the actual friction behaviour around the pulley arc. Work conducted by Harrison [2] developed a FEM model of the conveyor belt around the arc of the pulley, to determine the change in tension around the arc, and an effective coefficient of friction based on standard input values of 0.9 and 0.7 for static and kinetic friction respectively. His work concluded that the belt tension around the pulley displayed an s-curve response as shown in Figure 2, based on the ratio k= T1 T2 , with the effective coefficient of friction dependent on this ratio.

Given a value of k= T1 T2 , Harrison determined an effective coefficient of friction of 0.32 to 0.84, dependent on the tension in the system.

A fabric belt typically corresponding to lower tensions yields a lower effective value, compared to a higher tension steel cord installation.

Work by Tiwari et al [1] investigated the viscoelastic dependency (load and slip rate) on the coefficient of friction of ceramic lagging tiles on a rubber belt.

Ceramic lagging is commonly used in applications at risk of contamination, as the lagging has cylindrical protrusions extruded from the surface, which indent the rubber cover to aid traction.

What about across the pulley face?

A more recent development is the need to develop a deep understanding of the behaviour of friction across the pulley face. Euler’s equation, as well as much of the existing research focus on understanding the behaviour around the arc of contact, operating on the assumption that the viscoelastic behaviour, and thus the coefficient of friction is uniform across the pulley width. For a new installation, this assumption is valid, however as belt and lagging wear, the belt thickness and/or pulley diameter becomes less uniform, leading to stress concentrations within the belt being transferred to the pulley lagging. Build up or contamination of lagged surfaces has the same effect.

Conveyor belts wear for a variety of reasons on both sides. The carry side of the belt (top cover) typically wears most towards the centre, at the surface in contact with the bulk material.

Similarly, the return side (bottom cover) will typically exhibit localised wear

Implications for pulley design Drive and high-tension bend pulleys typically experience the highest tension in a conveyor system, and as such small

Figure 3: Relative cord position vs cord number across belt width [4].

60 І Australian Bulk Handling Review: September/October 2021

SAFER FOR SERVICE Increased production demands have resulted in faster, wider, more heavily loaded conveyor belts resulting in increased carryback.

Carry back leads to excessive wear on conveyor components, build-up on return idlers, misalignment of the belt and adverse effects on the conveyor operation and plant efficiency and increased OH&S risks.

Ceramic lagging on a high-tension bend pulley began to show premature damage along the centreline of the pulley.

changes in cord path length due to cover wear or pulley contamination leads to significant changes in the load sharing between cords. Some examples are highlighted below.

The ESS IPS Cleaners deliver superior belt cleaning performance and unparalleled serviceability for a variety of applications.

High tension bend pulley: iron ore

The IPS is an upgraded version of the ESS InLine 20-Ten Premium Cleaner & the original ESS InLine cleaner, which set the standard for cleaning performance combined with safety and ease of service.

Ceramic lagging on a high-tension bend pulley began to show premature damage along the centreline of the pulley.

The installed belt exhibited cover wear along the central section of the carry side, due to wear from the bulk material.

This change in belt thickness resulted in an increased stress along the centreline of the high-tension bend pulley, and subsequently failure of the ceramic bonding.

Design features of the new IPS Secondary Cleaner include; •

•

Drive pulley: Gold Upgrade of a conveyor belt in a gold mine to a higher strength, resulted in a significant increase in lagging wear, despite the same lagging being used successfully on the previous belt, and the same operating conditions of the conveyor. Drive and lagging design are all within current design specifications. While the cause of this failure is still under investigation, it is believed that an increase in stress

Stainless steel manufacture – to resist product wear and suitable for corrosive

High tension bend pulley: copper In a copper mine, signs of physical damage and delamination along the centreline of a high-tension bend pulley began to show after three months in operation. The installed belt exhibited cover wear along the central section of the carry side, resulting in increased stresses along the centreline of the high-tension bend pulley. This increase in stress lead to the increase in wear and subsequent delamination of the lagging.

Improved encapsulated slide design – reduces jamming for easier service

environments

•

New tensioning bracket design – increases the cleaners sensitivity to belt movement to maintain optimal cleaning pressure and angle

•

New Air and Spring Tensioner design – interchangeable to offer flexibility as the requirements of the client changes

•

Same footprint as the 20Ten Premium InLine cleaner - as a client 20Ten Premium cleaner comes to the end of its service life a new IPS Cleaner can be retrofitted.

was transferred to the lagging, resulting from the upgrade of the conveyor belt.

The existence of uneven load sharing between steel cords would likely present subtly in two ways; uneven lagging wear on the pulleys, and/or mis-tracking of the conveyor belt. This would develop with time, and without rupture or damage

Proudly Manufactured in Australia

PULLEYS

Figure 4: Tension (kN) within the steel cord cables at the point of first contact on the pulley, T1 (red line), and half-way (90°) around the drive pulley (blue line) [4].

of individual cords, is unlikely to be detected by current belt monitoring

within the contact is understood it will then be possible to review existing

systems. Detection of this sooner rather than later would help minimise fatigue to individual cords and splices and extend the service life of the belt.

lagging installations, and determine the maximum stress exhibited in these materials. This knowledge will allow a performance envelope to be defined for each lagging material and validated using the planned test facility. It will also be possible to extrapolate to the limit of allowable power transfer for a given drive design.

The future of research In response to these cases, Elastotec has partnered with the University of Newcastle to further develop the understanding of friction behaviour within a pulley contact. Experience from both companies has demonstrated that when it comes to friction of viscoelastic bodies, tests utilising static or rigid body dynamics can lead to erroneous outcomes, and in particular, curved surfaces behave differently compared to flat. To completely understand this behaviour, a full-scale test facility is currently being designed, and will be built at the University of Newcastle, with the capabilities of measuring crucial properties around the pulley circumference, and across the pulley face. Parameters such as normal load/ pressure, shear force, and belt tension are just a few that will be measured, for a given belt tension, lagging surface and angle of wrap. Tests will be conducted at installed operating tensions. Testing will be completed for a variety of lagging types, on new and used belt samples. In addition to this, used belt samples will be tested on both sides, to measure stresses around a high-tension bend pulley in contact with the carry side.

By extension, once the stress profile

Concluding remarks The inadequacy of a simple Euler friction model to predict friction behaviour around a pulley has long been known, however the extent of this

Upgrading the conveyor belt resulted in a significant increase in lagging wear.

62 І Australian Bulk Handling Review: September/October 2021

misunderstanding is only currently coming to light. Beginning as a means of preventing belt slip in a drive pulley, the complications associated with a lack of understanding of the drive traction can and is leading to failures of belt covers and lagging materials.

The intent of this paper is to raise awareness of emerging issues around pulley friction, the complexity of the issue, and the failures that may result.

A deeper understanding of friction and the stresses that result will allow engineered design of lagging materials and optimise lagging selection. As conveyors continue to grow in length and throughput, designers will have confidence in the lagging selection, and its performance under new and aged conditions. These topics are the subject of ongoing research.

References 1 A. Tiwari and B. N. J. Persson, “Conveyor Belt Drive Friction: Ceramic Lego Sliding on Rubber Belt.” PGI-1, FZ Juelich, Germany.

2 A. Harrison, “Modelling Belt Tension Around a Drive Drum,” Bulk Solids Handl., vol. 18, no. 1, pp. 75–79, 1998.

3 P. Robinson, C. Wheeler, V. Agarwal, W. Srinivas, and J. Guo, “Pouch conveyor drive system dynamics,” Int. J. Mech. Mater. Des., vol.

17, no. 1, pp. 187–199, 2021.

4 A. Reicks, “R&D Report - Theoretical Model to Evaluate Belt Wear Effects on Lagging Stress.”

Overland Conveyor Company, Elastotec Pty Ltd. 5 J. M. Hedgepeth, Stress concentrations in filamentary structures. National Aeronautics and Space Administration, 1961.

AD INDEX

SUBSCRIBE

To Australia’s only publication 100%-focused on bulk solids handling. It covers conveyors, silos, engineering, dust control, powder handling, weighing, pneumatics and much more, in industries such as mining and metals, ports and terminals, grain, fertiliser, sugar, salt, foods, milling, resins, cement and woodchips.

Advertiser

Page

Aerobelt............................................................................51 Allied Grain Systems.........................................................49 Altra Industrial Motion Australia .......................................7 Aspec Engineering............................................................39 Astec.................................................................................43 Aurora Process Solutions.................................................15 Bintech Systems...............................................................47 DSH Systems.....................................................................29 Dyna Engineering.............................................................31 Fenner Dunlop Conveyor Belting Australia.....................13

le ation

www.

www.bulkhandlingreview.com

VOLUME 26, ISSUE 5 | SEPTEMBER/OCTOBER 2021

w.com ngrevie GUST 2021 lkhandli LY/AU www.bu26, ISSUE 4 | JU VOLUME

ue: In this iss Showguide BULK2021 ers and scrapers Belt cleaning bulk handling Automat

s g System and material own), (sh treams ipment and ction equ atically. om s—aut

In this issue: Conveyor showcase Reducing your dust emissions Choosing condition monitoring

bu

lk ME 26 handlingr , ISSUE ev 2 | MA iew.com Y/JUN E 2021

VOLU

con

Flexicon Corporation Australia..........................Back cover

In this Silos anissue: Are taili d storage BULK20 ng dams viab le?

21

Jenike & Johanson...........................................................37 Kinder Australia................................................................55 Kotzur...............................................................................21 Martin Engineering...........................................................25 Mobile Conveying Services................................................5

pers e ox Tip Drum/B discharge conslide a te a nd ma per lid, open ses— ces etted hop nstream pro feed dow dust-free. cally and

Nelson Silos......................................................................57 BIGGEST STEMS RALIA’S SY OF AUST LL CONVEYOR NG ONE HI DELIVERI ROUND DOWN UNDERG

Grain conve storage s yor sy il stems os and specia lis

THE ORIGINAL LOW PROFILE FEEDER

Oli Vibrators......................................................................53 ts

RKM International Roller Company.................................33

II-0548

Bulk Bag oaders, Bag Unl g Systems ems, Bulk Handlin ng Syst t-Wide Bulk Conveyi Plan eumatic Automated world. out the ems, and

ademark

ADVERTISERS INDEX

Schaeffler Australia..........................................................19

ugh N thro

FLEXICO

4/27/20

11:38

AM

Schecnk Process Australia...............................................35 Sumitomo Drive Technologies........................................41

1 year

$99.00 (inc GST)

6 issues of Australian Bulk Handling Review and 1 copy of the Equipment and Services Guide 2 years

$179.00 (inc GST)

12 issues of Australian Bulk Handling Review and 2 copies of the Equipment and Services Guide

Transmin............................................................Front cover Tribotech...........................................................................23 TUNRA Bulk Solids Handling Research Associates.........17 Vega Australia..........................................Inside front cover Vortex Global......................................................................8

Subscribe today: www.bulkhandlingreview.com/subscribe

Reduce and Distance Plant Personnel while Boosting Output and Preventing Contamination with automated, enclosed bulk equipment and systems from Flexicon

Automated, sealed BULK-OUT® Discharger-Conveyor Systems replace multiple workers dumping hand-held bags manually, while preventing contamination.

Enclosed Bulk Bag Weigh Batch Systems feed a central weigh hopper mechanically, and remove weighed batches pneumatically, requiring labour only to attach/detach bulk bags.

Bulk Bag Discharging Systems can loosen solidified material and meter it into liquid streams (shown), screeners, size reduction equipment and continuous blenders—automatically.

Dual SWING-DOWN® Bulk Bag Fillers fed by weigh hoppers fill up to 40 bags per hour with only one operator connecting empty bags and one forklift removing full bags.

Flexicon Bulk Bag Filling Lines automatically dispense pallets, fill bulk bags, and disconnect/accumulate filled bags, minimising operator involvement.

TIP-TITE® Drum/Box Tippers seal, tip and mate a discharge cone to a gasketted hopper lid, open a slide gate and feed downstream processes— automatically and dust-free.

Flexicon automated equipment and systems can move your bulk materials at higher capacities with fewer personnel, cutting costs while distancing operators from one another.

AUSTRALIA sales@flexicon.com.au 1 300 FLEXICON +61 (0)7 3879 4180

USA SINGAPORE INDONESIA SOUTH AFRICA UK SPAIN FRANCE GERMANY CHILE

+1 610 814 2400 +65 6778 9225 +62 81 1103 2400 +27 (0)41 453 1871 +44 (0)1227 374710 +34 930 020 509 +33 (0)7 61 36 56 12 +49 173 900 78 76 +51 2 2415 1286

©2020 Flexicon Corporation. Flexicon Corporation has registrations and pending applications for the trademark FLEXICON throughout the world.

II-0548

See the full range of fast-payback equipment at flexicon.com.au: Flexible Screw Conveyors, Tubular Cable Conveyors, Pneumatic Conveying Systems, Bulk Bag Unloaders, Bulk Bag Conditioners, Bulk Bag Fillers, Bag Dump Stations, Drum/Box/Container Tippers, Weigh Batching and Blending Systems, and Automated Plant-Wide Bulk Handling Systems