Bulk Handling Today June 2018

BULK

HANDLING Endorsed by: CMA l LEEASA l SAIMechE l SAIMH

incident-free heavy lifting risks in transportation

T O D A Y

June 2018

Invest in Power Chiefton 2200

Ton for ton the cheapest Crusher in the Market.

Enough said...

www.elbequipment.com BRANCHES & DEALERS SOUTHERN AFRICA & SOUT AFRICA +27(0)11 306 0700

2

BULK HANDLING TODAY

June 2018

Distribution and Product Support

T O D A Y

BULK

HANDLING

June 2018

Contents On the cover: Tru-Trac Rollers (Pty) Ltd. Tel: (012) 661-9531 jonathan@tru-trac.com www.tru-trac.com

Quarrying

CMA News 9 SAIMH 18 LEEASA News Lifting 4

32 Addressing skills shotages 33

10 Substantial Fleet 12 More Cranes for Grootegeluk 13 Purely Electrical Portal Crane

Market Forum

Endorsing Bodies

Apron Feeder

14 Orders Roll In

•

CMA (Conveyor Manufacturers Association)

•

LEEASA (Lifting Equipment Engineering Association of South Africa)

•

SAIMechE (SA Institution of Mechanical Engineering)

•

SAIMH (SA Institute of Materials Handling) also mailed to members of the RFA (Road Freight Association)

Increasing Payload

17 Intermodal Side Tipper Bin

Power Transmission 19 Tapered Roller Bearings

Winder Enigneering

20 Vital to Retain Skills in South Africa

Manufacturing

23 Real-Time Manufacturing Solutions

•

Articulated Trucks 24 Operator Safety and Convenience

Beltcon 19

26 Surface Dynamics of a Rubber Covered Pulley

Copyright

All rights reserved. No editorial matter published in “Bulk Handling Today” may be reproduced in any form or language without written permission of the publishers. While every effort is made to ensure accurate reproduction, the editor, authors, publishers and their employees or agents shall not be responsible or in any way liable for any errors, omissions or inaccuracies in the publication, whether arising from negligence or otherwise or for any consequences arising therefrom. The inclusion or exclusion of any product does not mean that the publisher or editorial board advocates or rejects its use either generally or in any particular field or fields.

Our e-mail address is bulkhandling@promech.co.za Visit our website on www.bulkhandlingtoday.co.za

The monthly circulation is 3 673

Proprietor and Publisher: PROMECH PUBLISHING Tel: (011) 781-1401, Fax: (011) 781-1403 E-mail: bulkhandling@promech.co.za www.promech.co.za Managing Editor: Susan Custers Chief Editor: Danette Capper DTP: Anne Rotteglia Advertising Sales: Linda Patricio Antois-leigh Botma Subscriptions: Please email us at accounts@promech.co.za if you wish to subscribe to “Bulk Handling Today” at R550,00 (excl postage and VAT) per year; R1 380,00 per year for Africa/Overseas.

Printed by: Typo Colour Printing, Tel: (011) 402-3468 FSC (Forestry Stewardship Accreditation)

BULK HANDLING TODAY

June 2018

3

CONVEYOR MANUFACTURERS ASSOCIATION

From The Chairman’s Desk

W

hat an enjoyable evening we had celebrating the 45th CMA Annual Dinner at Bryanston Country Club recently.

The food and ambience were great (thanks go to the Club) and Donovan David Goliath entertained us all brilliantly.

The highlight of the evening was presenting the CMA Award of Excellence to our immediate past Chairman, Simon Curry. Simon also leads the team that has supported the project being conducted on the Uni-Directional roller rig that has been built by the CMA and installed at Dunlop premises on the East Rand.

The guests of honour this year were Bryan Moore and Terry Frangakis with their partners. Bryan is the Wits student conducting the tests on the rig on which his Master’s thesis is based, and Terry is the Wits Master students’ supervisor. Some very interesting data from this project will soon be available to industry.

4

Jay Pillay Chairman

SIGN UP FOR THE CMA CYCLE CHALLENGE TO BE HELD AT AVIANTO IN MULDERSDRIFT ON 13 JULY 2018

Honoured guest: Bryan Moore & Lindi Wiggins

Simon Curry receiving the Award of Excellence from Chairman Jay Pillay

Sennette & Jay Pillay

Honoured guest: Terry Frangakis and his wife Kate

BULK HANDLING TODAY

June 2018

Mandlonke Vesi & Santhanam Radhakrishnan (Tenova) The Zest table

The Brelko table: Riaan Rynders, Grant & Sharon Ritson, Sharon Padayachee

Simon & Hettie Curry

Danielle Djurdjevic & Gustav Leipolt (ELB)

The Brelko table: Craig & Leandri Abbey, Cecilia & Riaan Rynders

Membership at June 2018 All members subscribe to the CMA Code of Ethics ABB Industry Acrow Limited Actom Afripp Projects Altra Industrial Motion South Africa (Pty) Ltd Bauer Bearings International Belt Brokers Belting Supply Services BMG Bonfiglioli Power Transmissions Bosworth Brelko Conveyor Products CedoTech cc Closeal Manufacturing Collisen Engineering ContiTech South Africa (Pty) Ltd Conveyor & Engineering Equipment CPM Engineering CT Systems David Brown Gear Industries DRA Projects SA (Pty) Ltd

Dunlop Belting Products Dymot Engineering Company ELB Engineering Services Fenner Conveyor Belting (South Africa) Flexco SA (Pty) Ltd FLSmidth Roymec Giza Technologies (Pty) Ltd Habasit South Africa (Pty) Ltd Hägglunds Drives South Africa Hatch Africa (Pty) Ltd Hosch - Fördertechnik (SA) International Belting & Marketing (Pty) Ltd Iptron Technology KevConBelt (Pty) Ltd Lesa Mining Equipment and Conveyor Belt Lorbrand Martin Engineering Megaroller Melco Conveyor Equipment Moret Mining Nautilus Projects (Pty) Ltd Nepean Conveyors OE Bearings

Oriental Rubber Industries SA Osborn Engineered Products Pegasus Industrial Services cc Protea Conveyors Regal Beloit South Africa Rema Tip Top South Africa Ringspann South Africa Rossi Gearmotors (Pty) Ltd Rula Bulk Materials Handling Schaeffler South Africa SENET SEW Eurodrive Shaft Engineering (Pty) Ltd SKF South Africa Tenova Takraf ThyssenKrupp Industrial Solutions South Africa (Pty) Ltd Timken South Africa (Pty) Ltd Transvaal Rubber Company Voith Turbo Weba South Africa (Pty) Ltd WorleyParsons RSA Zest Electric Motors

BULK HANDLING TODAY

June 2018

5

6

Guests at SEW table

Tony Pinto & ELB guests

Brian Townsend, Beth Bach, Chris Townsend & entertainer Donovan Goliath

ThyssenKrupp

Zuzana Gough (KevConBelt guest), Jolene Saaiman (Timken)

ThyssenKrupp

Celeste Robinson & Sandra Padayachee (Voith)

Celeste Robinson, Sandra Padayachee & Vickey Padayachee (Voith)

BULK HANDLING TODAY

June 2018

CONVEYOR MANUFACTURERS ASSOCIATION

Shaun Santana, Almarie & Ken Purchase (Flexco)

Tony Pinto & ELB guest

Vickey Padayachee, Grant Robinson ( Voith) & Wilton Monnery (KevConBelt)

SEW guests

Raymond & Angela Obermeyer (SEW)

SEW guests

Sybil & Alan Exton

SEW guests

BULK HANDLING TODAY

June 2018

7

CONVEYOR MANUFACTURERS ASSOCIATION

8

Guests at the Dunlop table

Guests at the Dymot table: Martin Skeen, Ivana & Adi Frittella & Ivan Taljaard

Guests at the Dymot table: Ivan Taljaard, Elize & Paul Nel

Graeme, Janet & Eleanor Skeen (Dymot)

ELB Table

Carl van der Linda & Michelle (Flexco)

Bilal Dada, Kenny Padayachee, Craig Abbey (Brelko)

ThyssenKrupp guests

BULK HANDLING TODAY

June 2018

The South African Institute of Materials Handling

Sample

The South African Institute of Materials Handling (SAIMH) is a Non-Profit organisation set up with an objective to encourage the transfer of knowledge associated within the fields of Bulk Materials Handling (conveyors, stacker, reclaimers, tipplers, train loading systems, etc.) through a combination of seminars and networking sessions.

The SAIMH is made up of professional engineers, each practising their trade in a variety of organisations who volunteer their time to execute the SAIMH’s objective. The main aim is thus to promote the advancement of the art, science, theory and practice of the Bulk Materials Handling principles and techniques.

Company Affliates as at May 2017 Afripp Projects cc Brelko Conveyor Products (Pty) Ltd Bulkcon CPM Engineering CT Systems cc Conveyor Watch (Pty) Ltd David Brown Gear lndustries (Pty) Ltd ELB Engineering Services (Pty) Ltd Engicon Systems (Pty) Ltd Facet Engineering cc Flexco (SA) (Pty) Ltd

Hagglunds Drives SA (Pty) Ltd Hansen Transmissions SA (Pty) Ltd Hatch Goba (Pty) Ltd lllustech J & A Engineering Services Kimrae Engineering Prolects Loadtech Load Cells (Pty) Ltd MacsteelVRN Martin Engineering Melco Conveyor Equipment Morris Material Handling SA (Pty) Ltd

Osborn Engineered Products (Pty)Ltd PD Engineering Services cc PH Projects Holdings (Pty) Ltd Rio Carb (Pty) Ltd Sandvik Materials Handling Africa Screw Conveyors & Material Handling Senet SEW Eurodrive Spar Western Cape SSAB South Africa (Pty) Ltd Tenova Zest Electric Motors (Pty) Ltd

BULK HANDLING TODAY June 2018 9 Tel: (011) 867-0902  Fax: (011) 867-0036  Email: saimh@global.co.za  www.saimh.co.za

LIFTING

Substantial Fleet Babcock’s safety first philosophy has resulted in its plant hire business receiving two orders from Air Products South Africa to install two 88-tonne cryogenic tanks at its plant in Newcastle, KwaZulu-Natal.

F

ollowing the first successful, incident-free heavy lift in 2017, Air Products contracted Babcock to undertake the transport, cranage and rigging to install a second cryogenic tank at the same plant this year. The cryogenic tanks are used to store CO2.

The second installation will be undertaken by the Liebherr LTM1500 500-tonne mobile crane and multi-axle trailer, which was also used for the first lift. Despite it being an extremely large crane used for heavy lifts, the Liebherr LTM1500 is quick and easy to erect.

Michael Hawkins, Heavy Lift Manager at Babcock, says that the first tank was installed within four hours using a team of four Babcock employees and six rigging specialists.

“The first installation for Air Products went so well that they requested we manage the entire project for the second tank, including transporting the tank from Germiston to Newcastle, cranage and rigging,” explains Michael.

Air Products manufactures, supplies and distributes industrial and specialty gas products and chemicals to customers in South Africa and internationally in the steel, stainless steel, chemical, petrochemical, and engineering industries.

Michael reports that in addition to providing incident-free heavy lifting services to Air Products, the company has successfully completed various other heavy lifts in the last few months. Babcock prides itself on its safety record, which currently stands at 20 years without a single product fail or injury.

Transnet

In February 2018 Babcock received an order from Transnet to upright an 180-tonne electric locomotive that had derailed in Katu. As the line could only be isolated for three hours, the recovery of the locomotive was undertaken utilising a Liebherr LTM1400 and LTM1500 in tandem to place the locomotive back on the tracks.

“We provided the cranage and rigging and the successful outcome has since resulted in our receiving further orders for locomotive recoveries from Transnet,” says Michael.

Sappi

Earlier this year Babcock was called on by Sappi Ngodwana to install ten evaporator columns, ranging in mass from 36 to 74 tonnes, as well as the offloading of a complex cooler weighing 95 tonnes.

These lifts once again utilised the 500-tonne Liebherr LTM1500 mobile crane.

During Sappi Ngodwana’s annual shutdown in May, Babcock removed an existing cooler and installed a new cooler using a Liebherr LG1550; a 600-tonne lattice boom crane with 200-tonne counterweights on the carrier deck.

Footprint

The company is the largest empowered mobile crane and plant service provider in South Africa with a substantial fleet of cranes with lifting capacities from 8 to 600 tonnes. Specialities include the provision of mobile crane services, rigging equipment and expertise, abnormal transport, and welding and mechanical construction plant.

Babcock has a combined inventory of more than

10

BULK HANDLING TODAY

June 2018

LIFTING 40 000 items, distributed nationally and within the other South African Development Community countries, for a wide range of contracts ranging from infrastructure projects and mines to wind farms and marine projects.

The company moves equipment into place with a focus on safety and clear communication and planning, while its QR code scan and tracking system monitors the lifecycle of every single item of inventory, so as to have instant access to the items’ hire history, service intervals and related parts.

In addition, Babcock’s plant is serviced after every hire and inspections are carried out every three months to guarantee the highest in safety and operational standards.

Babcock, Michael Hawkins Michael.Hawkins@babcock.co.za

VISIT US! 10 – 14 September 2018 | Expo Centre, Nasrec, Johannesburg, South Africa BRINGING YOU THE FUTURE OF MINING, MANUFACTURING, ELECTRICAL AND POWER SINCE 1972

IT’S A SHOW THAT BELONGS TO YOU. Source 100’s of cutting-edge solutions Compare products and brands Get advice from technical experts Watch live demo’s For more information contact Leigh Miller: Acquire knowledge seminars Tel:at + free-to-attend 27 (0) 10 003 3060 Email: leighm@specialised.com

PLATINUM SPONSOR

GOLD SPONSOR

SPONSOR

FOR MORE INFO CONTACT: Leigh Miller I leighm@specialised.com I Tel: +27 (0)10 003 3060 Incorporating:

Brought to you by:

REGISTER ONLINE FOR FREE ENTRY!

www.electramining.co.za

LIFTING

More Cranes for Grootegeluk Exxaro has again chosen Condra to manufacture high-lift overhead travelling cranes for vehicle workshops at its Grootegeluk Coal Mine, near Lephalale in Limpopo Province.

O

rders for three cranes placed late last year bring to six the number of these machines supplied by Johannesburgbased Condra since mid-2016, with a total combined order value of some R10-million.

The first of the new orders, for two cranes, was secured by authorised Condra distributor H&H Specialised Services in November last year. A third crane was ordered in December and a further order for a fourth machine is expected soon.

Gearboxes across the hoist range were up-rated some years ago to deliver additional power, and the company today uses a 36B case-hardened material on most pinions.

H&H Specialised Services will supply staff and technical expertise to install and commission all new cranes, the first two of which have already been delivered. Both are 50-ton double-girder electric overhead travelling cranes with standard two speed hoists, and both have spans of 18,4 metres.

The third crane, delivered in April, is an 18,4-metre span 50/20-ton machine featuring variable frequency drives on the main lift, long travel and cross travel to facilitate precise positioning of very heavy loads.

The auxiliary hoist on this machine has a standard two-speed option, while lift heights of the main and auxiliary hoists are 16 metres and 17 metres respectively, similar to those of the first two cranes.

12

BULK HANDLING TODAY

June 2018

Live-axle drives

The design of all three machines was described by a Condra spokesman as “standard�, although they feature live-axle drives across their design in place of the more common ring-gear configuration, part of Condra’s mandate to keep maintenance costs to a minimum. Other non-standard elements of the Exxaro contract include special LED lighting, limit switches on the long-travels and cross-travels, and armoured cable on all wiring.

The Condra spokesman said that manufacture of all three machines had been straightforward except for painting, which took twice as long as the usual seven days because of heavy rains experienced during this final phase of manufacture. All cranes were nevertheless delivered on schedule.

Maintenance

Condra is in constant pursuit of lower machine maintenance costs, one result of which is the live-axle drives incorporated in the Exxaro cranes.

Gearboxes across the hoist range were up-rated some years ago to deliver additional power, and the company today uses a 36B case-hardened material on most pinions. This material, though expensive, is beneficial in extending crane lifespan.

Additionally, hoists are fitted wherever possible with high tensile-strength ropes to reduce rope diameter and enable a reduction in drum diameter and a smaller gearbox and motor. All these factors help the customer to contain costs.

Condra (Pty) Ltd, E-mail: sales@condra.co.za

LIFTING

Purely Electrical Portal Crane The new LPS 420 E is the latest extension of the Liebherr mobile harbour crane product range. This newlydesigned machine is a purely electric-driven portal crane. All crane movements such as luffing, hoisting, slewing and travelling are carried out by electric motors.

I

n common with the rest of the LHM series, it is characterised by high modularity. Therefore, it is a universal all-rounder and a key asset for handling every type of cargo, from containers to bulk, general cargo and heavy lifts up to 124t.

The machine is designed for ports and terminals with an electrical infrastructure.

Equipped with two winches, each with a powerful 190 kW electric motor, the LPS 420 E provides a maximum load capacity of up to 124 tonnes.

Therefore, the portal crane can be perfectly used for heavy break bulk as well as project and general cargo.

Bulk handling

With a turnover of up to 1 200 tonnes per hour, this new crane exceeds the average turnover of comparable electric-driven cranes in the market.

Given the maximum outreach of up to 48 metres, ships up to Panamax class can be served.

The main components of the E-drive are liquid cooled and the heat is dissipated by heat exchangers. The fully closed liquid cooling system, in combination with the heat exchanger, is installed on top of the slewing platform. Therefore no overpressure unit is necessary to prevent dust from coming inside the machinery house, which is a big benefit for cranes working in a dusty environment.

Latest Technology

The LPS 420 E is especially optimised for terminals with a power supply ranging from 380V to 460V. Thanks to the active-front-end frequency converter, deviations in the voltage supply can be compensated for easily making for a safe and stable operation. Due to limited space and harsh environmental conditions, a liquid-cooled and highly efficient multi-drive frequency converter system was implemented.

The frequency converters are Liebherr built components, which have proven themselves in their ship-to-shore gantry cranes and material handlers.

As an additional benefit, energy storage units can be used to reduce the peak-load in the crane main power supply and to take advantage of regenerative energy within the system.

The compact unit ensures a high power storage capacity, which enables the accumulation and supply of 200kW of power within 15 seconds.

Liebherr-MCCtec Rostock GmbH www.liebherr.com

Container handling

Productivity is a decisive factor in modern container handling. The LPS 420 E is an ideal solution for terminals where every container counts. With up to 30 cycles per hour, the LPS 420 E is the perfect solution when it comes to container handling performance.

The operator of this new crane can rely on very dynamic electric motors. Furthermore, the low moment of inertia ensures a fast response of the motor for precise drive characteristics. Due to the high motor speed spread, no gear shifting between normal and heavy load is required. This allows for uninterruptible power transmission from maximum load to maximum speed.

Another welcome side effect is that the noise emission of the planetary gear box is low.

Liebherr launches first purely electrical port crane

BULK HANDLING TODAY

June 2018

13

ORDERS ROLL IN South African manufacturer Osborn has recently netted orders for 13 apron feeders, reflecting the burgeoning demand for these robust, hard-working machines at mines around Africa and as far afield as Spain.

T

he company’s healthy apron feeder order book includes exports to Ghana, the Democratic Republic of Congo and Spain, as well as three machines for one of the country’s largest open cast coal mines in the Lephalale area.

“Customers are increasingly opting for our apron feeders which combine competitive pricing with exceptional quality,” comments product development director, Martin Botha.

When the feed material is wet, sticky or clay like, and where other feeding equipment cannot handle it, our apron feeder is the ideal machine for the job

14

BULK HANDLING TODAY

June 2018

The company has been contracted to supply four apron feeders to a new client for use in a Spanish copper mine. These are the first Osborn apron feeders sold into Spain, Martin reveals. One unit is 2.4m x 12m in size. The others are 1.5m x 6m machines. This significant order has a total value of around R26 million.

Large investment

One of South Africa’s largest open cast coal mines has invested in two new Osborn apron feeders as part of an upgrade programme to meet the coal supply demands of Medupi power station. These

APRON FEEDER new machines are 1.5m x 14m in size and have been customised to meet the client’s requirements.

The company will supply a 1.8m x 6.3m apron feeder to a mine in the DRC.

Their unique features include special paint, galvanising and guards, customer specific drives and tailor-made auto lubrication systems. The machines’ vast size poses some shipping challenges that Osborn will overcome by stripping the units into three segments for transport to the mine, Martin advises.

Heavy-duty construction

The scope of the company’s contract includes designing, manufacturing and supplying the apron feeders, as well as supervising their commissioning.

With their heavy-duty construction, these apron feeders are designed to handle feed sizes of up to 1 500mm. where no fines removal is required or where fines are removed by a separate dribble conveyor. “When the feed material is wet, sticky or clay like, and where other feeding equipment cannot handle it, our apron feeder is the ideal machine for the job,” he asserts.

The export order to Ghana comprises one 1.8m x 7m apron feeder, three 1.2m x 8.5m units and a 1.5m x 8m machine. “The scope of our contract includes manufacturing and supplying the units, complete with guards and hydraulic drives with power packs,” states Martin, noting that Osborn won this order based on the outstanding quality of its machines.

“It is exciting to have plants around the world recognising our well-established reputation for supplying apron feeders that are rugged, long wearing and capable of operating efficiently in the most arduous conditions,” Martin stresses.

Over many decades in business, developed a formula to determine the ideal size apron feeder for a customer’s requirements Martin explains that the apron feeder can be installed in a horizontal or inclined position (up to 15°), depending on space limitations. Outlining the Osborn apron feeder’s function in the circuit, he says that it provides a reliable means of controlling the feed rate to prevent surge loads to primary crushers, belt conveyors and other plant and equipment.

“Apron feeders are usually installed under a hopper or bin and can accept direct dumping by dump trucks, front end loaders and control ore feed from mine stockpiles.”

A complete range

Osborn offers a complete range of standard and extra heavy-duty apron feeders suited for the most testing conditions encountered in the mining and quarrying industries. Ranging in size from 900mm wide to 3 500mm wide, the apron feeders can be supplied in lengths to suit customers' requirements.

They are offered with either electro-mechanical or hydraulic drives. The cast steel or manganese flights are designed to overlap, to reduce spillage.

The machines are constructed using traditional D4, D6, D7, D8 and D9 track components.

Osborn has, over many decades in business, developed a formula to determine the ideal size apron feeder for a customer’s requirements. “Factors like flights and chain type; start-up and running torque; chain factor of safety; start-up conditions; and running conditions are all considered in the calculation.

"For drive sizing, we calculate breakaway torque; running torque; absorbed power; installed power; head shaft speed; and chain pull. Our vast experience and expertise ensures that end-users get the best machine and optimal performance,” Martin concludes.

Osborn Engineered Products Tel: (011) 820-7600 www.osborn.co.za www.astecindustries.com

BULK HANDLING TODAY

June 2018

15

Piecing together your success.

12415/E

We understand that you’ve been building your career piece by piece, and that all those hours, projects and plans allow you to live the lifestyle you deserve.

Partner with PPS, and let us help you ensure your success is more than the sum of its parts.

Proud sponsor of the SAICE Young Engineer of the Year.

Visit pps.co.za to find out more about our financial solutions for graduate professionals.

PPS is an authorised Financial Services Provider.

16

BULK HANDLING TODAY

June 2018

INCREASING PAYLOAD

Intermodal SIDE TIPPER Bin

O

ur intermodal tipper bins ensure quick, safe and cost-efficient bulk handling in rail and road applications. What’s notable is this intermodal side tipper bin system increases payload on rail wagons, from 54 metric tons to 60 metric tons. A single tipper bin is able to hold 30 metric tons for road transport,” explains Ken Mouritzen, director, SCA. “Robust intermodal side tipper bins are easily handled onto container rail wagons and road trucks by a container handler.

“Side tipper bins have been designed for rapid and efficient off-loading of materials from both rail wagons and road trucks, using specially designed hydraulic tipping cylinders," he adds.

They can be used across different modes of transport, including road and rail, without the need for investment in double handling cargo Operations

Specialised Container Agencies (SCA) has developed an intermodal side tipper bin, that provides efficient bulk handling rail solutions, encouraging greater utilisation of rail wagon container haulage.

“An important feature of these intermodal side tipper bins, which are able to be stacked two-high for storage, is they can be used across different modes of transport, including road and rail, without the need for investment in double handling cargo.”

This system is boosting the utilisation of rail infrastructure, which significantly reduces transport costs, decreases national road congestion and minimises product damage.

In areas that are not fully serviced by rail, the side tipper can be loaded onto road transport, for closed loop, shorthaul operations. Road vehicles are then used to carry the tipper bin containing bulk material to the railhead. This means cargo can be received at non-rail serviced facilities, for example on mines, terminals and ports.

Product integrity

For the transporter, benefits of using robust intermodal side tipper bins are lower operating costs. Minimal cargo loss and weather-proof tarpaulins ensure product integrity during transport. Advantages also include cost-efficient, easy handling of bulk, improved safety for drivers, vehicles and cargo, as well as reduced insurance premiums.

Specialised Container Agencies Ken Mouritzen, Tel: (031) 274 8270 Email: ken@specialisedcontainer.co.za

BULK HANDLING TODAY

June 2018

17

ENDORSER OF “BULK HANDLING TODAY”

LIFTING EQUIPMENT ENGINEERING ASSOCIATION OF SA

• A recognised ECSA Voluntary Association (VA) •

LEEASA is a fully-fledged association devoted to the lifting industry across Southern Africa. Members hale from the crane, forklift, mobile elevated work platform, aerial and suspended access platform, chain hoists, rigging and lifting tackle arenas, etc. Primarily devoted to the LMI’s (Lifting Machinery Inspectors), and LME’s (Lifting Machinery Entities), the association considers safety paramount. As such it serves in an advisory capacity to the SABS, the Department of Labour, various training bodies and the industry at large. LEEASA is recognised by ECSA as a voluntary association.

What’s in it for you:

As an Individual member who is registered as a Lifting Machinery Inspector (LMI), you may qualify for any concessionary fee granted by ECSA (this could save you over R1 000 a year).

and other training courses accredited by the association attract ECSA CPD points.

ECSA registered LEEASA members are awarded one Continuing Professional Development (CPD) credit each year. CPD is an ECSA requirement to retain registration.

Members benefit from the collective power of a recognised and established association and collective co-ordination in dealing with authorities in policy making and matters concerning the industry.

Members obtain a discount on LEEASA seminars. Both these

LEEASA has some 650 members (Individuals and Companies).

• • •

LEEASA Occupational Health & Safety Act and Regulations LEEASA Mine Health & Safety Act and Regulations LEEASA Lifting Equipment Inspection & Legal Compliance Register

Available for purchase online at www.leeasa.co.za

1 18

LIFTING EQUIPMENT ENGINEERING ASSOCIATION OF SOUTH AFRICA Head Office: 8 Boris Road, Bordeaux, Randburg, Johannesburg Tel: 074 900 8378 • www.leeasa.co.za Secretary: Arni Sommer • email: arni@leeasa.co.za

BULK BULKHANDLING HANDLINGTODAY TODAY

February June 20182012

POWER TRANSMISSION

Tapered Roller Bearings In today’s industrial world, customers need solutions that are robust enough to withstand the toughest challenges and the most testing environments while meeting ever growing demands. In addition, these solutions must work harder, longer and safer for improved uptime and subsequently greater productivity and efficiency.

S

KF is committed to gaining a deeper understanding of all these challenges and has focused on engaging with key customer groups to determine their individual requirements.

top spot for dynamic load ratings by up to 23%.

Improved performance is attributed to low friction torque, noise and vibration and increased speed and running accuracy.

Customers provided feedback, the company listens and responds by developing and enhancing their product and system solutions to ensure that customer demands are met.

Enhancements

Overcoming challenges

• Gearboxes include capabilities to support higher loads, withstand rugged conditions, resist contamination, enable easier mounting while maintaining the clearance pre-load and ensure an extended life span.

SKF Explorer tapered roller bearings present a perfect example of one such solution. Customer engagement has resulted in the development of an innovative, practical and uniquely designed bearing that is capable of overcoming a vast range of challenges. The SKF Explorer caters to all customer needs and is customisable for specific requirements.

Tapered roller bearings support heavy loads and improve execution during heavy-duty applications and in difficult conditions The bearing’s design features and manufacturing process reduce early failure and set the standard for high reliability. These dependable Explorer tapered roller bearings support heavy loads and improve execution during heavy-duty applications and in difficult conditions. The bearings have achieved the

Customer feedback on other SKF product offerings has resulted in the following developments and enhancements:

• Pinions and fluid pumps are able to handle inadequate lubrication, achieve increased speeds with lower friction, support heavy loads, maintain high stiffness under preload as well as offer low friction during running-in.

• Truck and trailer wheels are designed to provide reliable lubricant film formation in the rolling contacts, manage misalignment and cornering load, perform productively at low/medium speeds with varying loads.

SKF is represented in more than 130 countries and has around 17 000 distributor locations worldwide.

SKF, www.skf.com

BULK HANDLING TODAY

June 2018

19

WINDER ENGINEERING

VITAL TO RETAIN SKILLS IN SOUTH AFRICA Once a powerhouse of engineering skills to support the local mining industry, South Africa must now work harder to ensure that it retains and passes on this technical capability, especially in fields like mine winder manufacture and refurbishment. the design and engineering staff used to come from the workshop floor, so they had an in-depth understanding of what was required.”

IT and automation

With the application of computers to the world of engineering design, this is no longer the case, he notes, adding that this lack of shop floor expertise often needs to be mitigated, so that a supplied design can actually be functionally fabricated.

P

arnis Manufacturing works manager, Brian Berry, says it is a major concern, especially among mining companies and the medium to heavy engineering sector, that there is now a severe lack of skills in certain key engineering fields.

In fact, the majority of the winders used on mines on the continent were produced in this country In fact, a number of respected engineering companies that serviced the mining and associated industries no longer exist in South Africa.

“Over many decades, South Africa developed a depth of skills in the manufacture, repair and refurbishing of mine winders. In fact, the majority of the winders used on mines on the continent were produced in this country,” says Brian. “Even

20

BULK HANDLING TODAY

June 2018

“The shift away from ‘old-line’ manufacturing and toward more advanced, computer-assisted manufacturing has changed the industry significantly,” he adds. “The ongoing incorporation of information technology and automation into our manufacturing processes, for instance, has increased productivity and enhanced quality; but it is still critical that engineering expertise is available.”

He emphasises, however, that the shortage of skills should not be seen just as a problem. It is also an opportunity to leverage the country’s population of skilled artisans to pass on this important knowledge base, so that engineering and manufacturing operations in this discipline can be sustained.

“At Parnis Manufacturing, we regard our depth of experience as a major differentiator, and one which earns us the respect and support of various sectors such as mining and energy,” says Brian.

“With our 43 years in business, we are one of the remaining few players providing these solutions, and are using our proud legacy to help ensure the sustainability of this sector and the retention of skills in the country.”

WINDER ENGINEERING

This lack of shop floor expertise often needs to be mitigated, so that a supplied design can actually be functionally fabricated milling machines, as well as ancillary drilling and welding machinery.

Vertical boring

Concept to manufacture

"Offering skills from concept through to final detailing and manufacture gives us a huge advantage in our sector, especially as our services are backed by decades of specialised experience. This capability represents a valuable service for the customer, who appreciates its important impact on the quality of the final product.”

Parnis Manufacturing’s extensive 18 000 square metre facility in Tulisa Park, south of Johannesburg, includes over 8 000 square metres of workshop space. The company is able to deploy its skills base through its range of fit-for-purpose fabrication and machining equipment, including vertical boring machines, horizontal boring machines and CNC

Vertical boring capacity at the facility extends to a table size of 4,5m, a turning diameter of 5,3m and a turning height of 3,2m, with a maximum load of up to 50 tonnes. Its horizontal borers boast a capacity of up to 5,5m longitudinal travel by 2,5m high.

“Our large vertical boring machine puts us at an advantage to most of our competitors, and allows us to tackle a wide range of engineering projects,” Brian concludes. “Other equipment includes milling machines with 4,5m longitudinal travel and a 1,8m height and an overhead crane lifting capacity of 50 tonnes (tandem).”

Parnis Manufacturing, Mario Guerini Tel: (011) 613-3801 Email: mario@parnis.co.za www.parnismanufacturing.co.za

DEMAG V-GIRDER CRANES – NOW AVAILABLE UP TO 50 TON LIFTING CAPACITY.

+27 11 898 3500 www.demagcranes.co.za

BULK HANDLING TODAY

June 2018

21

22

BULK HANDLING TODAY

June 2018

ERP

Real-Time Manufacturing Solutions Fenner South Africa has chosen the next-generation enterprise resource planning (ERP) solution, Epicor ERP, to improve data accuracy, costing, integration and automation in their manufacturing process. This is to support the company’s goal of continued growth in Southern Africa.

T

he solution has been implemented by epic ERP, the value-added-reseller of Epicor ERP in sub-Saharan Africa.

Founded in 1861 in England, the Fenner Group was established to manufacture leather and encompassed belting, lacing and hoses. The company expanded globally over the next century and in 1960, Fenner South Africa officially opened its manufacturing facility and distribution outlet in Johannesburg.

Fenner South Africa has focused on the Group’s Engineered Conveyor Solutions (ECS) division, and their state-of-the-art plant produces and distributes solid, woven conveyor belting to the mining, power generation and bulk handling markets throughout Southern Africa.

International standards

Fenner South Africa had identified issues of data accuracy, costing and automation, and required an integrated, fit-for-use ERP system that could seamlessly be implemented in their manufacturing plant, to measure, manage and improve manufacturing efficiency.

“While we enjoy over 65% of the solid woven conveyor belt market, our focus is to steadily increase market share by continuing to secure contracts with major mining houses and allied industries. To ensure that all the products we distribute are reliable, of the highest quality and meet international standards, we need a reputable and cost-effective ERP solution,” says Chris Bekker, Financial Director of Fenner Conveyor Belting South Africa.

He continues, “One of our biggest requirements was that our selected ERP vendor have a thorough understanding of the manufacturing environment, with a successful implementation track record.

We conducted a comprehensive evaluation with a number of vendors and Epicor ERP’s manufacturing solutions stood out. In addition, their software has been effectively implemented in the

Fenner Australia and Fenner America businesses and has proven to be an invaluable tool in their manufacturing plants.

“As Fenner South Africa is similar to both businesses, we can leverage from prior implementation experience and learnings, and we are confident that this software, supported by epic ERP, can resolve our own issues of data accuracy, costing and pricing, integration and automation.”

Manufacturing efficiency

Stuart Scanlon founder of epic ERP says, “It was by no means an easy evaluation. We worked hard to show Fenner South Africa how Epicor ERP can improve their manufacturing efficiency, while also being a cost-effective solution. With an integrated ERP system, not only are you breaking down silos but you’re also bringing together all your operational systems. Fenner South Africa will get real-time insights and accurate data, allowing them to focus on profitability. Our team can’t wait to get started.”

While we enjoy over 65% of the solid woven conveyor belt market, our focus is to steadily increase market share by continuing to secure contracts with major mining houses and allied industries Sabby Gill, executive vice president marketing for Epicor International adds, “Our successful implementation track record in Fenner Group’s Australian and American manufacturing plants has given us invaluable insight into their manufacturing environment, so we’ll be able to hit the ground running.

“Through Epicor ERP, the Fenner South Africa team can measure and manage their manufacturing with greater efficiency, enabling them to retain their global tag of being a world leader in conveyor belting solutions,”he concludes.

Berkeley (on behalf of Epicor UK) Dani Kerby / Fiona Todd dani.kerby@berkeley.global fiona.todd@berkeley.global

BULK HANDLING TODAY

June 2018

23

ARTICULATED TRUCKS

Operator Safety and Convenience Three new articulated trucks have been extensively redesigned, enhancing the field-proven features and performance of their Cat C-Series predecessors (730C2, 730C2 EJ, and 735C) with new operator stations including innovative new controls, transmission-protection features, new hoist-assist system, advanced traction control system, new stability-assist system, and a fuel saving ECO operating mode.

I

n addition, the design of the 730 and 730 EJ is enhanced with automatic retarder control and a hill-start feature. The 735 retains these features from its C-Series predecessor and further incorporates significant design refinements that include a new C13 Acert engine, CX31 transmission (also on the 730 and 730 EJ) and structural and dimensional modifications that reduce empty weight by 22 percent, while retaining the productivity of the outgoing 735C. These features combine for an up to 19 percent gain in fuel efficiency.

Operator station

The cab’s new external “spinal-Rops design incorporates a rear-quarter glass that eliminates a

Monitors the working angle of the tractor and body as well as the grade, and cautions the operator if the machine is approaching the set threshold angle, stopping the dump process if continued action may result in potential tipping

24

BULK HANDLING TODAY

June 2018

structural pillar in the C-Series design, for enhanced rear visibility. Also, a new wake-up feature initiates the machine’s displays when the door is opened.

The door is of a lighter, stronger design with a shut-assist feature for improved sealing against dust infiltration. The overall cab design results in lower inside sound levels at 72 dB(A), a 7 dB(A) reduction compared with previous models.

Optional new infrared glass reduces solar heating inside the cab, and left- and right-hand sliding windows increase ventilation and facilitate communication with workers and the loading-vehicle operator. A new, automatic climate-control (HVAC) system positions more vents above and behind the operator for increased heating and cooling efficiency.

A new heated/cooled seat is designed to give operators increased adjustments that allow dialling in personal-comfort settings; also, the passenger seat now uses a flip up/down design and added cushioning.

Lighting

For added safety, a new lighting system, controlled

via a ground-level switch, illuminates the cab’s entry steps and hitch area. Optional integrated payload lights provide an external indication of payload levels for the loader operator. Optional long range, LED work lights improve visibility at night or in situations of lower visibility.

New cab-mounted mirrors, including a front-visibility mirror, enhance all-around visibility for the operator.

Exterior cab features include an improved flexible lower fender and a low-profile exhaust stack that need not be removed for transport.

The optional Cat Connect Payload technology calculates payload via sensors on the walking-beam suspension, and load-status lights at all four corners of the cab roof ensure visibility to the loader operator from any angle.

In addition, the standard Cat Detect/Stability-Assist system monitors the working angle of the tractor and body, as well as the grade, and cautions the operator if the machine is approaching the set threshold angle, stopping the dump process if continued action may result in potential tipping.

Further enhancing safe operation is the Cat Advanced Automatic Traction Control system, which features refined technology for proactively applying differential locks to avoid wheel spin. Also, a terrain-based, throttle-smoothing system prevents acceleration surges when travelling over extremely rough terrain that makes keeping a steady pressure on the throttle pedal difficult.

Innovative controls

A new combined transmission-and-hoist lever provides efficient, single-lever control of vehicle speed and body-hoisting functions to reduce operator effort and to automate repetitive operations. A switch in

The C13 engine used in all the new trucks is available in configurations to meet emission standards of both highly-regulated and lesserregulated countries the cab allows operators to choose either manual or assisted hoisting control, the latter selection automatically applying the waiting brake, shifting the transmission to neutral, and raising the body to maximum angle at engine high idle.

Assisted hoisting returns the body to the lower position at the flick of a switch. Both raise and lower functions feature automatic cushioning and speed reduction at limits of movements.

New buttons in the combined transmission and hoist lever allows for setting (limiting) machine speed and selecting the transmission waiting brake. In addition, a new shift-protection system brings the truck to a safe stop if a directional shift is made while the truck is moving. The new combined shifting/hoisting lever also incorporates a parking position. A tertiary brake switch sets the parking brake in the unlikely event of main and secondary braking malfunction The C13 engine used in all the new trucks is available in configurations to meet emission standards of both highly-regulated and lesser-regulated countries.

The 730 EJ is designed to eject loads while travelling, providing positive dumping of the entire load, and also to work in areas with overhead restrictions and with soft underfoot conditions with improved machine stability.

Caterpillar, www.cat.com

BULK HANDLING TODAY

June 2018

25

BELTCON 19

Surface Dynamics of a Rubber Covered Pulley The conveyor belt pulley plays a vital role in heavy industry. Continuous improvement in its design and manufacture has substantially increased reliability and capacity.

However, the work of the pulley ultimately must be accomplished at the outer surface where it engages the conveyor belt. For many years rubber lagging has been bonded to the pulley surface to improve this engagement via enhanced friction coefficient, but the manner in which the friction arises is complex and poorly understood, as evidenced by slip failures to this day. Another role of pulley lagging is to act as a sacrificial layer protecting the expensive pulley. Naturally, there is strong interest in extending the life of the lagging, which requires knowledge of processes that cause abrasion to it. There are also several designs and thicknesses of lagging available and knowledge of the interaction dynamics would clarify the selection process.

I

Brett DeVries

ndustry has long adopted standardised, uniform friction coefficients for rubber lagging. While they are a useful design tool, it is widely acknowledged that rubber does not behave with a simple, universal coefficient of friction. A recent study showed that friction coefficient decreased with increasing pressure at a given slip distance. Other studies6, 7 of rubber friction in tyres have described a complex frictional nature, where the rubber friction coefficient depends on slip history, contact pressure, and road asperity size due to viscoelastic energy dissipation in the rubber. This study sought to record generated friction coefficients as a function of pulley rotation to reveal the underlying timing and evolution of lagging friction while driving a conveyor belt.

were all measured as a function of pulley position as the pulley rotated through a 180째 wrap angle. By measuring belt displacement, detailed data could be gathered near the belt entry and exit points where wrap pressure had not yet developed and lagging shear strain has been reported5 to have large reversals. Belt displacements could also be correlated to belt shrinkage indicated by decreasing wrap pressure, and compared against lagging shear angle data to show slip areas. Wrap pressure was measured and used as a proxy for belt tension, but it also was needed to be able to calculate local coefficient of friction from the shear angle data. The technique for measuring shear angle differed from previous reports and contained variations.

Belt displacement, wrap pressure, and lagging shear angle

Groundbreaking work by Zeddies captured shear stress and wrap pressure under both laboratory conditions and in the field. The laboratory data supports a symmetrical pressure curve and shear stress plot, which were generated using steel cord belt and apparently solid rubber lagging. A detailed mechanism for generating this phenomenon was described7. However, the effect was not seen in this study, which used ply belts have modulus ratings in the order of 100 times less and also utilising an oversized pulley and highly grooved rubber lagging.

Experimental

Figure 1. Experimental setup illustrating the hydraulic tensioning system.

The third cylinder rotated the pulley by retracting the wrapped leaf chain.

Figure 2 Shear angle sensor

26

BULK HANDLING TODAY

Figure 3 Wrap pressure sensor

June 2018

A hydraulically tensioned test rig was constructed (Figure 1). It was designed to measure wrap pressure, lagging shear angle movement and absolute belt displacement for various lagging and belt types on a pulley being rotated through a 180째 wrap angle. Data collection began approximately 10째 before the entry nip point (Top Dead Centre) and continued until 10째 past the exit nip point.

Each tension cylinder had a 50 kN Figure 4 Belt displacement sensor

BELTCON 19

Belt Displacement vs. Pulley Rotation 65 kN/m Belt

Figure 5. Diamond pattern rubber lagging.

load cell to measure force. To separately measure the lagging shear stain and the belt movement, mechanical sensor elements were installed inside a custom 1 219mm diameter pulley. The pulley was installed in a steel framework such that hydraulic cylinders could apply adjustable T1 and T2 tensions while the pulley was rotated. Due to the slow speed of the test, the measurements were considered to be nearly static. An average test took approximately two minutes.

Figure 6. Belt displacement as a function pulley rotation angle for 609mm wide, 11.1mm thick belt with 1.6mm cover thickness at various tension ratios.

Belt Displacement vs. Pulley Rotation Inverted 65 kN/m Belt

The hydraulic pressure in each cylinder was controlled with an adjustable spring based relief valve. These valves were limited in precision for setting initial test parameters and also suffered from pressure changes due to fluid flow in the control manifold once test motions began. To compensate, the cylinder load cells were necessary to accurately record force data throughout the test and were used to reliably verify the tension ratios described in each test result. However, some nominal variation in the starting tension was assumed for each set.

One wall of the pulley could be removed to facilitate installation on measurement devices inside the pulley. Two arrays were mounted inside, each consisting of a lag- Figure 7. Belt displacement as a function pulley rotation angle for 609mm wide, ging shear angle sensor, a wrap pressure 11.1mm thick belt with 4.8mm cover thickness at various tension ratios. sensor, and a belt displacement sensor (Figures 2—4). Small holes were cut in the pulley shell for ι is the rotation angle of the encoder the sensors to acquire data.

The wrap pressure sensor (Figure 3) consisted of a small load The lagging shear indicator (Figure 2) consisted of a steel pin inserted into the rubber lagging (not shown) and received into a cone-shaped aperture in the pulley shell. Mounted to the pin was a UHMW slider that was attached to a rotatable low mass arm. This arm was secured to a 5 000 count rotary encoder. The angular movement of the pin could be derived from the arm movement using the below formula:

(1)

Where r is the centre to centre length of the arm L is the distance from the pulley surface to the center of encoder rotation

cell and a circular foot that pressed against the underside of the lagging layer. small preload was applied to assure positive contact and subtracted from the results.

Belt displacement measured the movement of the belt as compared to the pulley steel surface using the position of the belt when the pulley was at top dead centre, or 0° rotation, as the reference point. The belt displacement sensor) consisted of a 5 000 count encoder connected in a 2:1 ratio to an idler wheel via a miniature toothed belt to assure near zero slip between the wheels (Figure 4). The entire sensor pivoted on an axle to ensure positive contact with the belt and was held in contact via a tension spring (not shown).

This mounting arrangement caused the idler wheel to protrude above the lagging layer prior to engagement with the belt.

As the sensor array rotated to the entry nip point, the wheel would be depressed until flush with the lagging.

BULK HANDLING TODAY

June 2018

27

BELTCON 19

Belt Displacement vs. Pulley Rotation 175 kN/m Belt

the growth of the active arc. The larger ratios require more of the wrapped angle to sustain the tension change, thereby applying the tension change to a longer section of belt, which results in greater shrinkage.

This same belt was then inverted with the top cover facing the pulley to see the effects of increasing the bottom cover thickness. The Inverted Belt Displacement plot (Figure 7) again shows greater displacement as ratio increases. Comparison of the 3.1:1 ratios shows nearly identical displacements between the two tests.

However, the inverted belt has twice the displacement at the 10:1 ratio. Reasons for this are unclear at this time.

Heavier construction belt was also tested.

A 609mm wide, 22.2mm thick, four-ply, 175kN/m rubber belt, with 6.4mm top and bottom covers was tested at various Figure 8. Belt displacement as a function pulley rotation angle for 609 mm wide, tension ratios (Figure 8). This heavier 22.2mm thick belt with 6.4mm cover thickness at various tension ratios. belt experienced the onset of slip earlier However, this would create rotation of the wheel prior to pul- than the 65kN/m belt at the same ratio. It also was not able ley and belt contact. Due to this, data prior to 0° and after to reach the 10.0 ratio due to the onset of full macro slip.

180° pulley rotation was removed from the resulting graphs This demonstrates that the effective coefficient of friction is for clarity. The lagging bonded to the pulley was 100% rub- lower for the higher tension belt. This was due to lower fricber strip lagging with extensive longitudinal channels and tion coefficients predicted by the increased wrap pressure7. grooves (Figure 5). It was positioned on the pulley so that Lagging shear was also measured for the same three belt the shear measuring pin could be inserted approximately in configurations. Lagging shear is of interest because it indicates the middle of one of the large diamonds. the presence and magnitude of shear stress applied to the lagging surface. For these plots a positive shear angle corResults and Discussion A 609mm wide, 11.1mm thick, two-ply, 65kN/m rubber responds to a shear stress in the direction of pulley rotation. belt, with 4.8mm top cover and 1.6mm bottom cover was The first feature observed on the shear plots (Figures 9–11) tested at various tension ratios. Plots were made depicting is the small positive rise on the 'driven' curves which peaks belt displacement or movement for various tension ratios at approximately five degrees of pulley rotation. This small (Figure 6). Negative values represent belt movement in the peak arises due to compression of the lagging itself. Since opposite direction to pulley rotation. Increased ratios caused the belt is now moving about a smaller diameter, there is an increase in the belt movement in a non-linear fashion. A a slight reduction in the circumference. This results in the major contribution to the increase was belt shrinkage and belt overrunning the original position until the lagging has finished compressing. It should be noted that this overrunning occurs prior to full wrap pressure, so it has little effect from a wear or friction standpoint.

A second feature common to mid-ratio shear plots is a quick reversal in the shear angle which then seems to stabilize (Figure 9). This feature is correlated in the displacement plots, but the movement is small, < .25mm. Examination of the wrap pressure plots shows a slight cresting of the pressure and by necessity, tension. As the lagging is reacting to the torque being applied to the pulley, the negative shear angle in the lagging is accompanied by a backsliding movement and generates a corresponding slight increase in belt tension.

Figure 9. Measured shear angle in lagging layer as a function of pulley rotation angle 609mm wide, 11.1mm thick belt with 1.6mm cover thickness at various tension ratios.

28

BULK HANDLING TODAY

June 2018

The third feature of the shear plot is the knee in the curve (Figures 9–10). This is the onset of the active arc. It is correlated by the start of negative displacement motion and by the onset of wrap pressure

BELTCON 19 decrease. Negative displacement arises due to belt shrinkage due to tension removal from the belt. Initially this displacement increases the lagging shear angle until a maximum point is reached when the decreasing wrap pressure and the local coefficient of friction are in balance in the lagging shear stain and shear modulus.

Belt movement at this stage is entirely in a slip regime. Greater tension ratios require larger active arcs and induce more slip.

On the wrap pressure plots, full wrap pressure is not developed until roughly five degrees of rotation have occurred. There is a similar feature at the exit point of the pulley. There is also a corresponding decrease in the shear plots five degrees prior to the exit point of the belt. This feature has been previously identified and associated bending forces required to deflect the belt carcass5, but belts tested were all steel cable construction and pulley diameters Figure 10. Measured shear angle in lagging layer as a function of pulley rotation angle near the minimum recommended. Both 609mm wide, 11.1mm thick belt with 4.8mm cover thickness at various tension ratios. would create relatively large bending is found by T1 = 65.7kN/m and T1/T2 = 3.1, (T1-T2) forces. In this test, the pulley used exceeded the minimum solves to give total tension change of 44.5kN/m. Howpulley diameter by more than 250%, and the belt was a ever, the average tension change experienced by the belt low modulus, fabric ply belt. This should minimise bending is half that. Using the spring formula F=kx, (44.5kN/m) forces, and yet the effect remained. This indicates that the (.5)(.6096m) = (8070kN/m)*x. Calculated shrinkage is effect is independent of pulley diameter or belt construction.

1.68mm for a difference of .65mm.

The data supported the following observations: There is good support for the Wrap Pressure equation:

(2) Hence, pressure gradients are a good proxy for tension changes.

• Contrary to Zeddies5, shear strain was not symmetrical about the midpoint of the wrap angle. This can be explained if the surface speed of the pulley is fractionally slower than the belt.

• Even though there was no macro scale breakaway evident, clearly the large accumulated negative belt displacement in the maximum ratio plots indicate the lagging/belt interface had entered a regime of stick-slip frictional behavior. Stick slip is not a stable friction regime and material contamination, moisture, or rubber aging would all prevent these ratios from being used in practice.

Coefficient of Friction

Another goal of this project was to measure coefficient of

• For the 175kN/m 1:1: ratio plot, there is a negative spike in the shear stress prior to the entry nip point and a positive spike after the exit nip point. This supports the prediction

by Zeddies5 that the rubber lagging layer is bulging beyond the nip points due to wrap pressure. It is not found in 65kN/m belt, probably due to the lower wrap pressure.

• The sharp negative belt displacements that occur during the end of the pulley rotation can be compared against the displacement predicted by belt shrinkage. For example, the T1/T2 = 3.1 plot of the 65kN/m belt has a displacement change of 2.33mm from 105° to 175° rotation. The length of belt comprising an arc of 70° is 759.4mm. The spring factor per unit width is (belt modulus/belt length), which is (6129.4kN/m/m)/(.7594m) = 8070kN/m. The tension change

Figure 11. Measured shear angle in lagging layer as a function pulley rotation angle for 609mm wide, 22.2mm thick belt with 6.4mm cover thickness at various tension ratios.

BULK HANDLING TODAY

June 2018

29

BELTCON 19 Figure 12. Wrap pressure as a function pulley rotation angle for 609mm wide, 11.1mm thick belt with 1.6mm cover thickness at various tension ratios.

friction as a function of pulley position. Recently, several research papers concerned with tyre friction behaviour have linked the origin of rubber friction to slip history, temperature, and contact pressure3, 6. Since both slip history and pressure have been measured in this study, an examination of the resultant friction is possible.

Since the displacements are small and the SBR based lagging rubber is fully cured and carbon-black filled, the lagging was approximated as an isotropic material that follows Hooke’s law.

Therefore, shear stress should be proportional to shear strain:

τ= Gγ

(3)

Where G is the shear modulus of the rubber Rubber usually is considered to have a complex shear modulus, G(ω) +G’(ω).

However, in this situation the speed is very slow and the strain values are small so G has been approximated as (.33)E, where elastic modulus (E) was measured at 10% elongation.

Furthermore, shear stress is a result of friction shearing the surface of the lagging.

τ= μ*(pressure)

(4)

Coefficient of friction was calculated as a function pulley rotation for all three belts (Figures 15–17) using the above equations.

Figure 13. Wrap pressure as a function of pulley rotation angle 609mm wide, 11.1mm thick belt with 4.8mm cover thickness at various tension ratios.

The trend is for the friction to increase with the rotation angle. On the low ratio plots, the friction coefficient developed is initially small through the passive arc, and then rises quickly during the active arc. This is expected since the slip distance is increasing which is predicted to generate larger friction coefficients3, 6. However, the capacity for the rubber lagging to sustain traction while under diminishing pressures was substantial.

Both of the 65kN/m belts show very high friction coefficients for the T1/T2 = 10.0 plots. These values are best explained by an adhesion model of rubber friction, and would be compromised by the presence of dust, moisture or a lowering of the rubber surface energy by aging.

Figure 14. Wrap pressure as a function pulley rotation angle for 609mm wide, 22.2mm thick belt with 6.4mm cover thickness at various tension ratios.

30

BULK HANDLING TODAY

June 2018

BELTCON 19 Figure 15. Developed friction coefficient as a function of pulley rotation angle for 609mm wide, 11.1mm thick belt with 1.6mm cover thickness at various tension ratios.

The friction data shows a strong dependence on wrap pressure. Examination of the 2.0 ratio friction plots shows maximum friction for the 175kN/m belt of .32, while the average max friction of the 65kN/m belt was .45. This was despite the 175kN/m belt displacing twice the amount of the 65kN/m inverted belt and more than 3.5 times the regular 65kN/m belt. However, the evidence for slip distance influence is also present. On the 65kN/m friction plot, the increase in friction between 140° and 180° is .3. The predicted friction increase due to pressure reduction based on DeVries8 is only .1, so the remaining .2 increase is due to slip distance.

The method for predicting lagging friction now seems circular and iterative. First, tension is changed in the belt during the active arc2. The length of the active arc depends on the wrap pressure and friction developed, which generates surface traction to change the tension. Greater tension ratios require longer active arcs. But the active arc friction is dependent on wrap pressure and slip distance due to belt shrinkage.

Belt shrinkage is calculated using the belt modulus, active arc length, and tension change, which is back to the start.

This complex process gives rise to the measured friction coefficients, which developed in response to the demands of the system. The result is the robust drive system that has been successfully deployed worldwide. As demands vary, the active arc length changes and more or less friction is developed while utilising more or less slip and thereby, wear.

Figure 16. Developed friction coefficient as a function of pulley rotation angle for 609mm wide, 11.1mm thick belt with 4.8mm cover thickness at various tension ratios

Acknowledgements

The author gratefully acknowledges the expertise and assistance of Ross VanderWeide for the purchase and setup of the electronics and measurement software used to conduct the tests.

This paper was first presented at the Beltcon Conference in 2017.

Copyright is vested with IMHC. www.beltcon.org.za Brett DeVries, Flexible Steel Lacing (Flexco), USA www.flexco.com

Figure 17. Developed friction coefficient as a function of pulley rotation angle for 609 mm wide, 22.2mm thick belt with 6.4mm cover thickness at various tension ratios

BULK HANDLING TODAY

June 2018

31

QUARRYING

Addressing skills shortages Skills development in the surface mining profession has been shunted squarely into the international spotlight by South Africa’s opencast mining industry representative association, Aspasa, with its awareness-raising presentation delivered to an international audience of peers in Spain recently.

Nico Pienaar, director of Aspasa

T

he Global Aggregates Information Network (GAIN) focusses quarrying and surface mining industry associations on numerous topics raised by its members and discusses solutions and best practices from its members around the world.

Aspasa director, Nico Pienaar, says skills shortages are a major factor impeding the industry. “Through ongoing communication with its members, industry associations can play an important role in identifying problem areas and provide workshops or short courses to alleviate the problem.

Global practices

“Aspasa is also embarking on an ambitious plan to provide comprehensive, fully accredited qualifications in quarry management. This is being carried out in partnership with professional training company, Prisma Training Solutions.

“Our relationship with GAIN spans a number of years and continues to unearth valuable information and practices that are shared across the globe and we are hoping that raised awareness and the development of training to address skills shortages can yield input from fellow members.

“South Africa is not uniquely experiencing skills shortages, but rather it is a global problem, and one that we hope to solve together,” says Nico.

Call for participation Aspasa already has its own health and safety, as well as environmental management systems which are mandatory for its members to ensure safe and sustainable supply of materials to various markets.

But the creation of bespoke quality management system designed with local requirements and legislation in mind, is the next logical step in maintaining the association’s status as a world-leader in driving the interests of the surface mining industry.

According to Aspasa director, Nico Pienaar, strict new requirements are being placed on the supply of materials for building (sand, aggregates, dimension stones), foodstuffs (salt), energy (coal, ash) and other minerals which requires modern quarries and surface

32

BULK HANDLING TODAY

June 2018

He continues that although the problem is common, South Africa has its own unique challenges and opportunities. To be successful all training needs to be undertaken in line with the Skills Development Act and according to the South African Qualifications Authority (SAQA). It may also tap the resources of the Sector Educational and Training Authority (Seta) to derive funding and methodologies.

Unique requirements

In addition, such coursework should address the needs of the Mining Qualifications Authority (MQA) to ensure competence within the specific area of mining.

It will also recognise Social Labour Plans, Sectoral Skills Plans and BBBEE requirements of the industry in order to build and develop individuals in pursuit of a career path in quarry management.

“While we have shared our experiences with the rest of the world, we are continuing to develop our own coursework and will welcome input from our global partners and local members. The more input we have, the better we will be able to develop a course that is relevant locally and abroad,” concludes Nico.

Aspasa, Nico Pienaar Tel: (011) 791 3327, Email: nico@aspasa.co.za Web: www.aspasa.co.za

mines to implement advanced process control and quality management systems to ensure that they comply.

“The development of a comprehensive quality management system based on international standards is therefore imperative and urgent. As a result, we have established a qualified task team to delve further into these different requirements and identify key areas to be covered generally and separately as per each segment of our industry.

“We cannot however cover every angle on our own and therefore encourage our members and their clients to play an active role in the formulation of our quality controls and systems.”

To contribute to the formulation of quality criteria contact Aspasa, Nico Pienaar, Tel: (011) 791 3327, Fax: 086 647 8034, Email: nico@aspasa.co.za, Web: www.aspasa.co.za

MARKET FORUM

ALL BRANCHES EQUIPPED WITH WATER BAGS Load testing of cranes is a vitally important part of Konecranes’ service and maintenance programme, especially where older cranes are concerned.

In order to speed up the load testing and avoid downtime, all Konecranes branches are now equipped with their own water bags.

Konecranes South Africa has also designed and manufactured a mobile test crane for load testing on site.

The customer no longer has to wait for his or her lifting equipment to be returned to site, as all the units are tested on the customers' premises, in their presence. This service

is unique as it can print the Load Test Certificate on the spot.

Lifting equipment is certified proof load tested in accordance with all safety aspects and regulations. This rig can test from chain blocks (manual and air driven) to lever hoists, coffin hoists etc.

The mobile test rig can handle a 30t capacity and it has a heavy duty battery back-up where electricity is not available.

The advantage of testing in this manner has proven far better and much quicker, improving Konecranes' service.

“Our investments in fully equipping our branches with mobile test rigs and our own static weights and branded water bags has already proved to have tremendous benefits and advantages,” says John MacDonald, Service, Sales and Marketing Director of Konecranes.

“It has most certainly raised the bar in our industry and set new and higher standards in service delivery.

Konecranes www.konecranes.co.za

Manufacturing Facilit y in Australia Martin Engineering has been a supplier of premium components since 1944, providing bulk handling solutions and flow control equipment into Australia through a licensee since 1978. As from September 2017, its new factoryowned manufacturing facility will provide direct sales, service, training and manufacturing to the continent, serving key industries such as mining, cement, sugar, quarrying and bulk handling ports.

of its kind dedicated solely to producing belt cleaner blades.

The move will provide factorydirect customer access to locallymanufactured products, as well as technical service from experienced and factory-trained technicians.

Company officials say that having local production will also allow Martin Engineering to supply its products at lower prices, reducing the overall cost of ownership.

Among the manufacturing capabilities are the firm’s proprietary technology for producing belt cleaner blades, using its custombuilt work cell. The manufacturing cells are designed, engineered and constructed by Martin, and the unique processing technology is being implemented at Martin locations on six continents to deliver premium-quality

A technician assembles a CleanScrape Belt Cleaner

components around the world with unrivalled consistency and wear life.

The system is believed to be the only one

Martin Engineering’s supplier for the chemical components of its urethane formulations is BASF Corporation.

By mixing, forming and curing its own belt cleaner blades in the modular work station, rather than subcontracting the production as most suppliers do, Martin Engineering takes complete control of the entire process, allowing one-day turnaround on most orders and even same-day shipping in many cases.

Says Chief Technology Officer, Paul Harrison, “Even the suppliers that are manufacturing their own blades are typically using pre-mixed urethane formulations and just pouring them into moulds. Our system delivers precise control and quality assurance, and remote monitoring allows technicians to investigate the causes of any faults and offer fixes to operators without having to travel to the site,” he concludes.

Martin Engineering Email: info@martin-eng.com www.martin-eng.com

BULK HANDLING TODAY

June 2018

33

Your boutique business destination Surrounded by lush gardens in the hub of Johannesburgâ&#x20AC;&#x2122;s northern suburbs, The Peartree in Craighall Park caters for groups of two through to 100 guests in nine well-appointed and equipped business suites.

Breakfast meetings, working lunches, indoor or outdoor dining, half-day and full-day packages including all welcome refreshments, teas and lunches are offered in Standard, Gold and Platinum packages.

Secure parking, business centre, fibre optic broadband AV, lockable space, all underpinned by highly qualified and helpful staff dedicated to ensuring your event is a success, make The Peartree a destination of choice.

www.thepeartree.co.za e-mail: info@thepeartree.co.za Tel: 011 781 1401 41 St. Albans Ave, Craighall Park

34

BULK HANDLING TODAY

June 2018

MARKET FORUM

Full range of wear solutions From impact to sliding abrasion, Rio-Carb has a full range of wear solutions for a range of materials-handling applications.

material for chutes, cyclones, skips, feeders, crushers, dozers, haul trucks, excavators, and draglines.

This wear-engineering specialist can become involved as early as the design stage in order to ensure that all operating conditions and parameters are catered for, explains director, Sias Suurd. This ranges from installing sacrificial surfaces (liners) to replaceable parts (maintenance).

Materials range from Chromium Carbide (CrC) overlay plate to high-impact plate, 400 and 500 Brinell material and most recently, ceramics.

Rio-Carb also offers a modular chute concept to eliminate health-and-safety risks associated with liner maintenance.

Modular chutes are more easily transportable, with a 30% weight saving.

Liner wear can be measured externally by means of an ultrasonic thickness tester. Chutes can be designed from standard-size wear panels, which reduces the number of parts required and subsequent stockholding.

CrC overlay plate comprises a ductile and weldable backplate, a quality-controlled fusion zone, and a hard chromium carbide overlay. It is an ideal wear-resistant

Rio-Carb www.riocarb.com

Africa and the Middle East, from the gold mines of West and East Africa to the copper mines of Central Africa.

Infrastructure development in the Middle East has also been important driver of the aggregate business, with resultant demand for Weir Minerals’ crushers and screens.

“To ensure the effective application of our growing equipment range, we place experienced process engineers at the centre of our relationship with customers,” says Steenbok. “This is key to helping customers drive down their cost of ownership while raising efficiency, productivity and profitability.”

“We are here for the long haul,” Vernon concludes, “and our investment in developing and acquiring leading brands, alongside our commitment to world class expertise, shows our commitment to the future of our customers and the mining industry as a whole.”

Spanning all the Processes Adding a partnership with technology group Andritz to its range of Trio crushing equipment, Enduron screens and other established brands, Weir Minerals Africa is further entrenching its position as a total solution provider to process plants.

General Manager Comminution at Weir Minerals Africa, Vernon Steenbok says, “Our offerings to mines now span all

processes from the run-of-mine tip to the tailings dams including equipment such as crushers, conveyers, screens, feeders, pumps, cyclones, linings, hoses and valves.”

Vernon emphasises that the company has been expanding into the comminution space as a vital part of its total integrated solution provided to customers across

Weir Minerals Africa, Rajen Govender Tel: (011) 929-2701 Email: rajen.govender@mail.weir www.minerals.weir

BULK HANDLING TODAY

June 2018

35

MARKET FORUM

energy efficient motors well,” National Sales Manager Norman Maleka comments.

Stricter international regulations have meant that all two-, four- and six-pole asynchronous motors with a power rating of 7.5 kW to 375 kW must meet the requirements of energy-efficiency class IE3 in the European Union (EU).

SEW-Eurodrive offers the DRN series as a complete range. “It sets the standard.

A customer who buys a gearbox or drive from us will automatically have an IE3compliant motor,” Norman stresses.

“What is equally important is the fact that the DRN series is downward compatible with our previous motors, regardless of the energy class. It fits right onto our gearboxes, for example, which means no additional effort on the part of our customers.”

While South Africa does not face the same regulatory pressure as the EU, SEW-Eurodrive has decided to raise the benchmark locally by launching its new DRN series as its standard range of electric motors.

“We also have to take into account our customers across our borders. For example, if we supply an OEM in Africa carrying out a project in the US, the IE3 requirement has to be met. We not only supply the local market, but have to take our export obligations into account as

LOW-RISK TERMS As the fines recovery gains achieved

by Reflux Classification (RC) technology are extended to a wider range of commodities, FLSmidth is making mines an offer they can’t refuse: to share the value of expanded production, including retreatment of waste dumps, at no cost to themselves.

The profit-share option is one of a range of contractual and financial alternatives that the leading engineering Original Equipment Manufacturer (OEM) is putting on the table as part of its commitment to sustainable productivity for its customers, according to FLSmidth’s capital sales director for sub-Saharan Africa, Roy Hazell.

Another feature is a global stator, which boosts both parts availability and stockholding.

Norman Maleka

“We can even operate the plant on the customer’s behalf; no one knows our equipment better than we do and we can ensure that it performs to expectation.”

Other options for customers include a toll treatment arrangement, while some customers may prefer to purchase the solution outright and operate it themselves as a standalone unit to augment production levels.

Roy says the modular RC solution is ideal for any mining company that has dumps or stockpiles of fines where they would like to recover minerals, but where the quantities do not justify the building of a dedicated fixed plant. The modular format allows a short term treatment plant of capacities around 100 tph to be set up without disrupting any existing process facilities.

“We are putting our money where our mouth is: this is how confident we are in this technology,” says Roy.

36

BULK HANDLING TODAY

June 2018

SEW-Eurodrive www.sew.co.za

At the same time, the modular format can even be expanded for customers who want production capacity up to 400 to 600tph although these plants are more likely to a fixed solution.

PGM producers have gained particular value from RC technology in terms of recovering chromite, a contaminant in PGM concentrate, as an added source of revenue.

FLSmidth, Tel: (010) 210-4820 www.flsmidth.com Stacker booms for an FLSmidth modular RC plant

MARKET FORUM

Winding Rope Attachments

Installation of Becker Mining South Africa’s winding rope attachments at a mine in the western limb of the Bushveld Complex is now complete and is ready to be put into full production.

“This equipment - which was designed and manufactured locally

by Becker Mining South Africa - covers the specific winding requirements of this underground mine,” says Tom Searle, senior general manager: mechanical, Becker Mining South Africa (Pty) Ltd. “Four sets of head rope attachments and four sets of tail rope attachments are required for the 4,5m drum diameter Koepe winder, which accommodates 38mm head ropes and 40mm tail ropes.

“A Becker Thimble type capel is fitted to the ropes with an hydraulic adjusting linkage fitted between it and the conveyance. This linkage ensures there is equal sharing of the load between the four head ropes.

“Complete 30ton Rocket type safety detaching hook sets were supplied for the man/material winder, which has a 4,88m drum and 51mm ropes. A set of 5ton Rocket type safety detaching hooks was manufactured for the service winder, which has a 26mm rope fitted.”

Rocket safety detaching hooks are designed to detach the winding rope from the conveyance in the event of an overwind and arrest and suspend the conveyance in the headframe. This patented design caters for the prevention of partial detachments while in service.

Becker Mining also supplied WRC clamps that were used during installation and will be utilised in future maintenance of ropes. A complete spare set of rope attachments was also supplied to the mine.

Hook sets, which were supplied complete with catch plates and jack catch boxes, are mounted in the headgear as a critical safety feature to prevent injury to personnel and damage to the shaft infrastructure should an overwind occur.

Becker Mining South Africa Email: info@za.becker-mining.com www.za-becker-mining.com

PALIFENCE NEW

WELD FREE PALISADE WELDED MESH •Save on transport •Ease of assembly •Save on storage •Follows surface contours •Installed, DIY, Trade

•Good viewing visibility •Complete system •Longevity – Zincalu or Zincalu and plastic coated •Secure and discrete POOL

FENCING

High Security Welded Mesh Palisade Gates Gate Automation Electric Fencing and more…

MARK: 083 454 6488

HEIDI: 083 334 4835

www.palifence.co.za BULK HANDLING TODAY

June 2018

37

MARKET FORUM

DANGER of using fake parts

to negotiate a matching, or even better, price for OEM parts for our clients.

This ensures that not only are we able to maintain our market share, but we prevent customers from jeopardising the productivity of their operations and the safety of their workers,” Deric stresses.

“Customers need to understand the overarching value of genuine versus imitation parts.”

Using imitation or fake parts in OEM equipment poses a major risk to the health and safety of machine operators, in addition to being hugely detrimental to the overall performance of the equipment, warns Bobcat Equipment South Africa, part of the Goscor Group of companies.

‘Grey market’ goods not only pose a potential danger to customers, but also

Government applications MST backhoe loaders have been recognised as the most suitable machines for demanding work at all levels of government including municipalities.

According to Desmond van Heerden of ELB Equipment, distributor of MST backhoe loaders in South Africa, the multipurpose capabilities of the MST backhoe loader combined with its high specification level, durability and national support network has contributed towards the popularity of the machine in the private sector and, more recently, its capabilities have boosted it to the front of the queue on the government’s national tender process.

present a serious business challenge.

Due to the economic downturn rendering the market highly price-sensitive at present, National Parts Manager Deric Knox comments that the best strategy is to educate end users about the disadvantages, and hidden costs, posed by fake parts.

“In the majority of cases, we are able

Having passed all the criteria for suitability, durability, pricing and local support with flying colours, the MST backhoe loader is now establishing itself as the defacto machine across all tiers of government. The reasons for its popularity are easy to see when looking at its value offering in the 8-ton and above machine range, plug-and-play hydraulics for accessories such as hammers, multi-purpose buckets, augers and more, as well as a full array of easy to use features – including a fully automatic transmission.

“It is big and powerful enough to be used on road projects, trenches, land clearing operations, excavations, cleaning operations and almost any other type of work that our government departments and municipalities may need. Simultaneously,

The MST backhoe loader can work around the clock’

38

BULK HANDLING TODAY

June 2018

For example, Bobcat has designed specific filters for its machines. Nongenuine filters cannot handle the same throughput, or last as long, which poses a significant risk to equipment. “While cheaper-priced parts may be tempting, it is important for customers to assess the long-term performance impact these will have on their equipment,” Deric concludes.

Goscor Group Debby Marx Tel: (011) 230-2600 Email: dmarx@goscor.co.za www.goscor.co.za

it is simple enough to be serviced and maintained internally if need be and offers a level of sophistication usually associated with considerably more expensive top-tier machines," says Desmond.

“Yet, despite its high specification levels and heavyweight capabilities, the MST is priced among smaller, less well-equipped mid-tier machines. Furthermore, it is distributed and supported by our heavyweight South African supplier network, which means it can be procured, serviced and maintained properly across all corners of the country.”

ELB Equipment Desmond van Heerden Tel: (011) 306-0700 Email: desmondv@elbquip.co.za www.elbequipment.co.za

We drive Industry

Quality. Innovation. Efficiency.

Gear units and motors from SEW-EURODRIVE have always set the trend and established new standards in drive technology. For this reason, the quality label â&#x20AC;&#x153;made by SEWâ&#x20AC;? has become a hallmark of quality in the drive industry. Market-orientated products developed and manufactured in-house, as well as uncompromising quality, are the cornerstones of our success.

SEW-EURODRIVE - Driving the world

BULK HANDLING TODAY

June 2018

39

Tough demands have met their match.

With a hydraulic drive system from Hägglunds, you get compact, durable power - without foundations or gearbox. A full range of rugged motor types and complete solutions for monitoring and control give you total assurance, even in the most demanding applications.

Let us know your demands.

Hägglunds Drives South Africa (Pty) Ltd P.O.Box 2851, 1610 Edenvale, Johannesburg Phone: + 27 (0)11 454 4933, Fax: +27 (0)11 454 5088 E-mail: info@za.hagglunds.com, www.hagglunds.com

Our drive is your performance.