2015/04 - Bullk Handling Today

BULK

HANDLING

T O D A Y

April 2015 Endorsed by: CMA l LEEASA l SAIMechE l SAIMH l

ContiTech Conveyor Belts Conveying Excellence

SURVEY ON THE LIFTING INDUSTRY DISSATISFACTION WITH MOSH PRACTICES 1

BULK HANDLING TODAY

February 2012

BULK HANDLING TODAY

April 2015

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BULK HANDLING TODAY

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BULK

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Contents On The cover:

4

SAIMH News

Continental ContiTech Tel: (011) 248-9337 www.contitech.co.za

5

CMA News

37 Fundamental to Equipment Reliability

Quarries

39 Mosh Practices Not for Everyone

Cover Story 6

A Force to be Reckoned With

Lifting

41

Market Forum

Endorsing Bodies

8 Lifting Survey 13 South African Project 17 Crew Transfer Methods

•

CMA (Conveyor Manufacturers Association)

•

LEEASA (Lifting Equipment Engineering Association of South Africa)

Logistics

•

SAIMechE (SA Institute of Mechanical Engineering)

Beltcon

•

SAIMH (SA Institute of Materials Handling)

Power Transmission

•

also mailed to members of the RFA (Road Freight Association)

10 Leeasa

News

19 New Laydown Area 21 Solids and Belt Interactions During Transport 33 Improving Motor Efficiencies

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.promech.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 Advertising Sales: Surita Marx DTP: Zinobia Docrat / Jacqueline Nene Subscriptions: Please email us at accounts@promech.co.za if you wish to subscribe to “Bulk Handling Today” at R475,00 (excl postage and VAT) per year; R1 190,00 per year for Africa/Overseas.

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

BULK HANDLING TODAY

April 2015

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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 April 2015 Afripp Projects cc Bearings lnternational (Pty) Ltd Brelko Conveyor Products (Pty) Ltd Bulkcon CPM Engineering CT Systems cc Conveyor Watch (Pty) Ltd David Brown Gear lndustries (Pty) Ltd East Rand Engineering Services 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 John King Chains (SA) (Pty) Ltd 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 TWP Projects (Pty) Ltd Zest Electric Motors (Pty) Ltd

4Tel:BULK TODAY 2015 (011)HANDLING 867-0902 l Fax:April (011) 867-0036 l Email: saimh@global.co.za l www.saimh.co.za

CONVEYOR MANUFACTURERS ASSOCIATION

From The Chairman’s Desk Dear CMA members

One of the most pleasurable tasks associated with writing this page is to announce new members to the Association. This month we welcome Cedotech cc, represented by Henk Brink and we look forward to a long and mutually beneficial relationship between Cedotech and the CMA.

Simon Curry

April 1st was the start of the new CMA financial year and already the months ahead are brim-full of interesting events for members. Membership certificates for 2015/2016 are ready for collection at CTR offices.

We are glad to note that many of you include the membership certificate in your tender documents.

The successful candidate achieves a CMA Certificate in Chute Design Training

The CMA is launching two new training programmes in 2015.

The Introductory Course in Belt Splicing will go ahead in June and as space is very limited on this course and a high degree of interest has been shown, make sure you apply for registration as soon as possible. Only two courses are scheduled for this year.

The CMA and CMMS/WITS have reached an agreement to host a Chute Design course, which is scheduled to be held in July. The course will comprise two days theory training by Tunra and a third day devoted to South African practicalities with lectures by our own South African experts.

Following the three days of theory, an assignment will be set and upon successful completion of the assignment, the student writes an examination.

Both the assignment and examination are set, marked and moderated by the CMA and thus the successful candidate achieves a CMA Certificate in Chute Design.

For details on all training courses, keep an eye on your Email Inbox and also on the website www.cmasa.co.za, or you can contact the Secretariat on 011 888-7163 who will keep you updated.

Simon Curry, Chairman

Membership at March 2015 All members subscribe to the CMA Code of Ethics ABB Industry Actom Afripp Projects Atlanta Manufacturing Bauer Bearings International Belt Brokers Belt Reco Belting Supply Services Bibby Turboflex BMG Bonfiglioli Power Transmissions Bosworth Brelko Conveyor Products Brevini Power Transmission SA (Pty) Ltd CedoTech cc Collisen Engineering Conveyor & Engineering Equipment Conveyor Watch CPM Engineering CT Systems David Brown Gear Industries DRA Projects SA (Pty) Ltd Dunlop Belting Products Dymot Engineering Company

ELB Engineering Services Facet Engineering Fenner Conveyor Belting (South Africa) Flexible Steel Lacing SA FLSmidth Roymec Hägglunds Drives South Africa Hansen Transmissions SA Hatch Goba Africa Hosch - Fördertechnik (SA) International Belting & Marketing Iptron Technology Lesa Mining Equipment and Conveyor Belt Lorbrand M & J Engineering Martin Engineering Megaroller Melco Conveyor Equipment Moret Mining MS Conveyor Pulleys SA Nepean Conveyors NSK South Africa (Pty) Ltd OE Bearings Oriental Rubber Industries SA Osborn Engineered Products Pegasus Industrial Services cc

PH Projects Holdings Protea Conveyors Read Swatman & Voigt Regal Beloit South Africa Rema Tip Top South Africa Renold Crofts Rula Bulk Materials Handling Sandvik Materials Handling SA Schaeffler South Africa SENET SEW Eurodrive Shaft Engineering Shaw Almex Africa SKF South Africa Sprag Components cc Tenova Takraf ThyssenKrupp Industrial Solutions South Africa (Pty) Ltd Timken South Africa (Pty) Ltd Transmission Components Transvaal Rubber Company TWP Projects Veyance Technologies Africa Voith Turbo Zest Electric Motors

BULK HANDLING TODAY

April 2015

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COVER STORY

A Force to be Reckoned With The purchase of Veyance Technologies by Continental and the subsequent merger thereof into its ContiTech division has vaulted the company internationally to the top of the ladder. In Africa it will strengthen the Continental foothold significantly and growth is on the cards.

C

o n t i Te c h h a s wasted no time getting down to business following the conclusion of the $1,9 billion deal. Merging two internationally-renowned companies is no easy task and the deal was subject to regulatory approvals and other closing conditions, while also scrutinized in fine detail by antitrust commissions for months.

But with the legalities finally all over, “Bulk Handling Today” speaks to Marketing Paul van Zyl, Marketing and Sales Administra- and Sales Administrations tions Manager for Continental ContiTech Manager, Paul van Zyl about what industry can expect.

“In South Africa it has been an extremely smooth transition that got off to a very early start that has resulted in a good acceptance all round,” Paul tells us from the company’s Johannesburg office.

In fact, they had aimed to host launches and presentations across the country once agreements had been reached in all the countries. Because of the

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April 2015

significance of the acquisition, the anti-competitive behavior and the impact on respective markets, the entire deal was under a magnifying glass. In several countries there were some legal requirements that had to be met and the process took slightly longer than anticipated.

Expand our team into Africa and already strategies are being developed in this regard Key markets

“By the time the acquisition had been concluded, this deal had been understood by all and we’ve just carried on with business as usual. Our customers have very readily accepted and understood the strategic approach of the acquisition and our integration into ContiTech.”

While the company, as a legal entity due to contractual reasons, will trade as Veyance Technologies for the foreseeable future, all products are branded Continental ContiTech. “We are very excited about the future following this deal,” Paul adds. “Part of the decision to purchase Veyance was to complement the ContiTech division in key markets where its presence has been limited. South Africa is one of these areas and our local plant in Uitenhage will provide opportunity for the company.”

African growth

It is not only in South Africa where the focus lies either, Paul asserts. “The aim is to significantly increase the ContiTech footprint in Africa where major growth is being forecast in the future.”

COVER STORY

ContiTech and Veyance are a great fit for each other, and complement each other very well geographically. ContiTech’s conveyor belt group and fluid technology business units, in particular, are set to benefit from the enhanced global presence that has been achieved through the deals. Also the power transmission division and air spring systems will achieve enhanced results.

“Now ContiTech and Veyance are key players in the technical rubber industry with approximately 41 000 employees on a global scale,” says Paul.

Undoubtedly a force to be reckoned with as benefits all around through innovative production technologies will ensure greater production efficiency. “These are strong reputable brands coming together because strategically they fit hand in glove.”

While growing their footprint has been a goal for the team, it’s not been possible until now. “The focus on Africa is increasing. We forecast the continent to be a massive player in the market. Thanks to this merger we now have the backing to expand our team into Africa and already strategies are being developed in this regard.”

“There is a lot of competition in the African arena at the moment but due to the global boost that has been achieved with the integration of two renowned companies, we believe we are ideally placed to become market leaders on the entire continent,” Paul adds.

New products on offer

The merger will also see the local market – and the rest of the continent – exposed to products and services previously not on offer. “We are now part of the biggest international conveyor manufacturing group internationally. It’s early days but customers

can look forward to our combined, increased product range over the next few months,” says Paul. He highlights that while their focus is predominantly on the mining and industrial sectors, they are well positioned to expand their expertise and reach across various sectors.

Although just the tip of the iceberg, customers can already be on the lookout for troughable tube conveyors with ContiClean A-H anti-stick coating, the Flexowell (conveyor belts with corrugated sidewalls and cleats for conveying masses at gradients of up to 90°), Sicon (an enclosed conveyor belt for small radii) and the Pocketlift, a conveyor for the vertical transport of large masses.

Our access to the innovation, research and development and a truly global footprint Significant benefits

New systems and processes that will ultimately enhance efficiency and productivity are also on the cards. “Our customers stand to profit from the merger of the two companies not only in South Africa, but the world over. The approach that has been taken throughout this process has been extremely open and transparent. There are significant benefits all round through our wider range of products, our access to innovation, research and development and a truly global footprint,” Paul concludes.

Continental ContiTech, Paul van Zyl, Tel: (011) 248-9337, Email: Paul.Van.Zyl@contitech.co.za, www.contitech.co.za

BULK HANDLING TODAY

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LIFTING

Lifting Survey Anglo Lifting Equipment

Condra

Fastlift Cranes & Services

FB Mining & Lifting

Konecranes

Total Number of Employees

28

±100

8

130

160

Number of years operating in SA Employees with Tertiary Qualifications ISO Accredited

10 6 No

48 25 Yes

25

6 Yes

24 60 No

Private 1

Private 6 R24 million 6 R18m 150 tons 70 70%

Private 4 R18 million R18m 75 tons 30 80%

Private 5 R10.8m 60 R6.6m 3 3%

Private 6 R15 million 60 R100m 265 tons 21 11%

R200m

R2-3m

R280 000

R50m

ü

ü ü ü

ü

ü

ü

ü

ü ü ü ü ü ü ü ü

Name of company

Ownership BEE Rating Total value of last two contracts Number of Projects completed in 2014 Value of largest contract completed in past 5 years Size of largest contract in terms of weight lifted Number of export orders over past five years Percentage of total business Total value of export orders over past five years Types of LIFTING EQUIPMENT handled CRANES Container Crawler Gantry Habour Jib Mobile Overhead Tower LIFTING TACKLE Chains

ü ü ü ü

ü ü ü ü

ü

ü

ü

Grabs

ü

ü

ü

ü

ü

Hooks Lifting attachements Magnets Shackles Spreaders Steel rope Webbing slings LIFTING DEVICES Cable pullers Chain blocks Hoist Lever hoist LIFTING MACHINERY Forklifts Reach stackers Lift trucks Primary area of lifting expertise Design Import/Export Installation and commissioning Manufacture/assembly Turnkey Service Support Assembly on site Commissioning Maintenance contracts Manufacture and delivery to site On site annual shutdown service On site supervision Personnel training LMI or LME inspections Professional affiliations

ü ü ü ü ü ü ü

ü ü

ü ü ü ü ü ü ü

ü ü

ü ü

ü ü ü ü

ü ü ü ü

ü ü ü ü

ü ü ü ü

ü ü ü

ü

ü

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BULK HANDLING TODAY

ü

Yes

ü ü ü ü

ü ü

ü ü

ü ü ü ü ü ü ü ü ü ü ü ü ü ü LEEASA

April 2015

ü ü ü ü ü ü ü ü ü ü ü ü ü SAIMH,

ü ü ü ü ü

ü

ü ü ü ü ü ü ü ü ü ü ü ü CMA LEEASA, ECSA LEEASA, ECSA, MVSSA

ü ü ü ü

ü ü ü ü ü ü -

LIFTING

GM Technical Services

HBC Radiomatic

Linde Material Handling

32

8

228

21 7 No

10

±19 103 Yes

Private 3

100 tons

ü ü

Yes Private 2 ±300 tons -

8 R41m 15 R100m 45 kg 227 6.7%

-

R±131m

ü ü ü ü ü ü ü ü

ü

LMI Academy 4 Permanent 10 Sub-contractors 10

Marine Equipment Supplies

MFN Lifting Systems

Premier Load Testing & Services

34

22

15

25

5 4 No

6

No

Yes

Private 4

Private R2.5m

400 tons 10

R3m 40 tons

R2m 125 tons -

-

-

ü ü ü ü ü ü ü ü

ü ü

No

Private 4 R2m 6 R1.5m 460 tons -

4 R3m

ü

ü ü ü

ü

ü

ü

ü

ü

ü

ü

ü

ü

ü

ü

ü ü ü ü ü ü ü

ü ü ü ü ü ü ü

ü ü ü ü ü ü

ü ü ü ü ü ü ü

ü ü ü ü ü ü ü

ü ü ü

ü ü ü

ü ü ü ü

ü ü ü ü

ü ü ü ü

ü

ü ü ü

ü Import

ü ü ü ü

ü

ü ü ü ü ü ü ü

ü ü ü ü ü

ü ü ü ü ü ü

ü ü ü ü -

ü -

ü ü ECSA

ü ü ü

ü

ü ü ü ü

ü ü LEEASA

ü LEEASA

ü

ü ü

ü ü ü ü ü ü

ü ü ü ü

ü LEEASA, ECSA

ü LEEASA, ECSA,LMI

BULK HANDLING TODAY

April 2015

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LIFTING EQUIPMENT ENGINEERING ASSOCIATION OF SA

LEEASA, formed in 2003, is a division of the Chamber of Engineering Technology (COET), a non-profit organisation. The association’s objectives include, but are not limited to: the transfer of knowledge and training within the field of the Lifting Industry, to improve safety, promote the use of standards and to promote Professional and Ethical practices.

I

t is represented on the Engineering Council of South Africa (ECSA) and a number of ECSA committees as well as on various task teams at the South African Bureau of Standards (SABS).

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).

ECSA registered COET / LEEASA members are awarded one Continuing Professional Development (CPD) credit in category

3 each year. CPD is an ECSA requirement to retain registration.

Members obtain a discount on training and seminars validated by the association, especially useful in earning ECSA CPD credits.

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.

LEEASA has some 500 members (Individuals and Companies).

Tel/Fax: (011) 787-1302, Email: engineer@netactive.co.za, www.leeasa.mirrorz.com 10

BULK HANDLING TODAY

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BULK HANDLING TODAY

February 2012

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LIFTING

Lifting Survey Name of company Total Number of Employees Number of years operating in SA Employees with Tertiary Qualifications ISO Accredited Ownership BEE Rating Total value of last two contracts Number of Projects completed in 2014 Value of largest contract completed in past 5 years Size of largest contract in terms of weight lifted Number of export orders over past five years Percentage of total business Total value of export orders over past five years

Searle Hoist & Tool

Special Industrial Supplies

Ustica Platinum Services

43

55

25

7

119 4 Local & 15 International Yes

32

19

Yes

8 2 No

Private 4 -

Private 3 -

150 -

400 tons 650 25%

2 R200 000 120 R1.9m 150 tons 25 5%

-

R30m

R1.1m

Types of LIFTING EQUIPMENT handled CRANES Container Crawler Gantry Habour Jib Mobile Overhead Tower LIFTING TACKLE Chains

ü

Grabs

ü

Hooks Lifting attachements Magnets Shackles Spreaders Steel rope Webbing slings LIFTING DEVICES Cable pullers Chain blocks Hoist Lever hoist LIFTING MACHINERY Forklifts Reach stackers Lift trucks Primary area of lifting expertise Design Import/Export Installation and commissioning Manufacture/assembly Turnkey Service Support Assembly on site Commissioning Maintenance contracts Manufacture and delivery to site On site annual shutdown service On site supervision Personnel training LMI or LME inspections

ü ü ü ü ü ü ü

Professional affiliations

WH Lifting & Handling

Yes Private 4

ü

ü ü

ü ü ü

ü ü ü ü

ü

ü ü

ü ü ü ü ü

ü ü ü ü ü ü ü

ü ü ü

ü ü ü Import ü ü

ü ü ü

ü ü ü

ü ü SABS TC 1020, LEEASA, ISO TC 111

ü ü

ü ü

ü ü ü

ü ü

ü ü ü ü ü

ü ü ü ü ü

ü ECSA

BULK HANDLING TODAY

April 2015

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Stay up and running. Uninterrupted.

Metso portable plants allow you the use of various crushing and screening operations: from a single, stand-alone unit to two-, three-, even four-stage complete plants providing several end-product fractions. The LT series complete plants can be easily adjusted to accurately suit your crushing application. You can choose feeding to crusher or feeding to screen options to meet your end-product requirements. Quick move and setup times allow minimum loss of production. This combined with the support and backup service of Barloworld Handling keeps you up and running. Uninterrupted.

LOWEST SUSTAINABLE COST PER TONNE. For more information contact your local Metso Mobile salesman, call +27 (0)11 045 6167 or email ggehrung@bwmetso.co.za

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BULK HANDLING TODAY

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LIFTING

South African Project A number of logistical hurdles have been overcome to supply Illovo Sugar’s new 51 000sqm warehouse.

Africa's leading sugar producer, supplying a raft of countries from the 170 000 tonne capacity facility.

Street Crane teamed up with its local partner GMTS to supply and install a range of lifting and materials handling equipment.

Illovo's warehouse is split into various zones. Each of the six bays, which are located within zones one and three of the warehouse, incorporate a crane featuring a 16 tonne safe working load. These 30.72 metre span double girder cranes include control cabins, link beams, lifting beams, access walkways and bogies that were manufactured by GMTS in South Africa using designs from Street Crane.

Corner-lift a lifting beam that is capable of handling ten one-tonne international bulk containers (IBC’s) of sugar per movement From left to right. Andrew Pimblett (MD of Street Crane UK) Mark Mackenzie (My Business Partner) and Hannes Steenberg of GMTS

T

he new facility is a combined initiative between Illovo and developer, Collins Property Group, with the operations outsourced to Barloworld Logistics. The company is South

The UK company supplied 12 eight tonne VX hoists, which were custom built twin hoists reeved on a single hoist drum to help ensure synchronised hook movement. GMTS then stepped in to synchronise the twin hoists on each crane through the use of encoder feedback and inverter drives. Each of BULK HANDLING TODAY

April 2015

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Tough demands have met their match.

With a hydraulic drive system from H채gglunds, 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.

H채gglunds 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.

14 BULK HANDLING TODAY April 2015

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LIFTING

these cranes will corner-lift a lifting beam that is capable of handling ten one-tonne international bulk containers (IBC's) of sugar per movement.

Bespoke design

The Street Crane VX is a bespoke design, open winch format hoist that features a dual-scrolled barrel to help ensure that there is no lateral movement of the load during the hoisting and lowering process.

The hoist mechanisms are M8, heavy duty rating, which Street Crane says reflects the high frequency of crane use for product movements. The cranes are specified with long travel speeds of 60 metres per minute, and cross travel speeds of 20m/m as well as hoist speeds of 7.8 m/m.

GMTS has incorporated automated safety systems that recognise identification tags on personnel and forklift trucks, which stop the crane and avoid collision with the lifting beam. In addition, radio control from the cabins is supplied by GMTS, together with electrical power distribution via an insulated conductor system that supplies power to the master hoist panel. While this project did not involve the construction of the largest cranes GM Technical Services has ever built, the Illovo commission proved to be a major challenge for both companies.

Logistics challenge

The route from GTMS' factory in Vereeniging to Illovo's facility in Msunduzi passes through three provinces. As a result, special permits were required

for such large loads to pass through each area while each convoy of three cranes took two days to make the journey.

The crane bridges became the spine of the vehicle connecting the cab to the dolly As a result of the convoy's size, the completed cranes required a safety vehicle escort. In addition, independently steerable dollies were used in place of fixed wheel vehicles to give additional manoeuvrability to the transport. Therefore, the crane bridges became the spine of the vehicle connecting the cab to the dolly.

Skilled service

According to GMTS' Hannes Steenberg, the company was awarded the Illovo Sugar order because it is one of only a few companies in South Africa that can couple the experience and capability to offer M8 equipment while also meeting such a "demanding and complex" specification.

"Despite the technical complexity, exacting schedule and logistics challenges, we met all deadlines throughout the project. Our commitment to the project will continue as we have undertaken an agreement to maintain the equipment for a further five years following commissioning," Hannes concludes.

GM Technical Services, Tel: (016) 428-1462 Email: sales@gmts.co.za, www.gmts.co.za

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LIFTING

Helicopter vs. marine transfer

Crew Transfer Methods With oil prices dropping, budgets in all areas of offshore operations, including crew transfers, are coming under pressure.

The question that many operators are currently faced with is how to cut costs but maintain a strong safety culture?

T

he safety benefits of marine transfer over helicopter transfer have been frequently debated in recent years, especially in light of a number of fatal helicopter ditchings.

In a recent study, marine transfer was highlighted as a substantially safer methodology over that of helicopter transfer. An analysis of incident data revealed that the risk of fatalities for marine transfer was estimated as 11 times lower than that of helicopter transfer.

Transferring crew by helicopter involves a huge initial financial outlay as well as a commitment to costly lifetime maintenance. A day’s operational downtime experienced as a result of helicopter groundings, for example, can cost operators hundreds of thousands of dollars in lost earnings.

Marine-based methods of crew transfer involving vessels and personnel capsules lifted by crane can be a cost-effective and safe alternative and provide the greatest impact on safety for each dollar invested.

With other less advanced rope style baskets on the market, it has often been the misconception that the Frog is a more expensive option than the rigid basket. Sales manager for Reflex Marine, Grant Wintle comments, “We have undertaken a study which proves on paper that the Frog-XT is the most cost effective option when taking into account product lifecycle.

“If you take four-person transfer devices, for example, the Frog-XT4 costs up to 5% less than a rigid basket over the lifetime of the product.

It also lasts up to 33% longer, costs up to 38% less to inspect and maintain and is up to four times faster to inspect and maintain, reducing downtime”.

Reflex Marine, www.reflexmarine.com

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Total Materials Handling Solutions Tenova TAKRAF’s world-class materials handling technologies, proven in applications throughout Africa, provide the mining and industrial sectors with comprehensive materials handling solutions from mine and industrial production facilities, to in-plant materials handling and outloading at rail and port terminals, and to ship loading and unloading.

■ Mining: Mobile Transfer Conveyors/Belt Wagons • Belt Conveyor Systems • Spreaders/Cross Pit Spreaders • Conveyor Bridges • Transport Crawlers • Apron Feeders ■ In Plant and Overland Materials Handling: Overland and In-plant Belt Conveyors • Pipe Conveyors • En-masse Conveyors and Bucket Elevators • Hot Materials Handling • Pneumatic and Vacuum Conveying ■ Stockyard Handling: Stackers • Reclaimers • Stacker/Reclaimers • Scraper Reclaimers ■ Outloading: Rapid Rail Loading Systems ■ Port Handling: Continuous / Grab Type Ship Unloaders • Ship Loaders 58 Emerald Parkway Road, Greenstone Hill Ext 21 Johannesburg 1609, South Africa P +27 11 201 2300 enquiries.TMM@tenova.com www.tenova.com

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TENOVA is a worldwide supplier of April advanced technologies, products and engineering services for the metals and mining & minerals industries BULK HANDLING TODAY 2015

LOGISTICS

New Laydown Area

Linda Sityoshwana, CDC’s trade solutions project manager

The Coega Development Corporation (CDC) has announced plans to invest R9-million in the establishment of a new laydown area, serving as a temporary storage site for abnormal cargo. The lay down area, located on the boundary between the Port of Ngqura and the Coega Industrial Development Zone (IDZ), will stretch across 12 hectares of land in Zone 1.

T

o date, the Port of Ngqura has been the port of entry for major abnormal-sized equipment, particularly wind turbine components and items such as the cold box units for the Afrox and Air Products air separation units, among others.

The deep-water Port of Ngqura is a transhipment hub and an ideal entry point to South Africa for abnormal cargo due to the draft depth, dedicated berth for general cargo and uncongested nature of port operations. The ease of movement and good road condition from the port through Coega IDZ onto the national road (N2) is an additional benefit for shipping to and from the Port of Ngqura.

Logistics

“The laydown area thus provides an essential component to the logistics value chain; enabling cargo shortto-medium term storage,” says Linda Sityoshwana, CDC’s trade solutions project manager.

The development of the laydown area entails two phases over the next year, and ambitious plans are also on the horizon to develop the area into a hub of maritime economic activity. “In Phase One of the project, the CDC will establish a multi-user facility for abnormal and out of gauge cargo storage, such as components of renewable energy manufacturing enterprises in the IDZ,” says Linda.

“It is further possible that maintenance work for marine drilling or production rigs can also take place in this designated area, so closely situated to the Port of Ngqura. In fact IDZ’s are designed in part to offer such back-of-port services.”

Phase two

It is foreseen that during Phase Two, which will be undertaken within the 2015/2016 financial year, Zone 1 will be declared a customs controlled area (CCA). This means that users of the laydown area will be able to benefit from the duty and VAT incentives available within a customs controlled area.

Zone 2 of the Coega IDZ was already designated a CCA in May 2014.

Future investors and tenants likely to make use of the laydown include Project Mthombo, the ferrous metals plants, and the biofuels facilities.

The laydown area will allow tenants of the area to move cargo between the port and IDZ, within an allocated space through a dedicated entrance, reducing heavy traffic on the main entrance route to the port.

Coega Development Corporation Dr Ayanda Vilakazi, Tel: (041) 403-0464 Email: ayanda.vilakazi@coega.co.za

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RFA Convention 2015 24 24 -- 26 26 May May 2015, 2015, CHAMPAGNE CHAMPAGNE SPORTS SPORTS RESORT, RESORT, DRAKENSBERG DRAKENSBERG Join us as the trucking fraternity comes together once again to discuss, debate and ponder over the challenges, opportunities and idiosyncrasies of the trucking industry. Centered on trucking and themed “Truckcentricity” - this year’s conference takes place over three days at Champagne Sports Resort situated in the tranquillity of the Central Drakensberg.

“Truckcentricity” will showcase the following: • • • • • • •

Practical implementation of the consignee/consignor legislation The BBBEE Sector Code for the Road Freight & Logistics Industry Road safety - the cause & prevention of Accidents Greening the trucking industry - Lessons from the USA Meeting Supply Chain Expectations Impact of the Power Crisis in the Road Freight Industry An analyst’s view on the bond market downgrade & stability & volatility of our labour market For more information please contact Shantal on 011 974 4399 or email events@rfa.co.za

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BULK HANDLING TODAY AprilTRUCKS, 2015 WITHOUT

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BELTCON

Solids and Belt Interactions During Transport This paper presents findings from a research program aimed at investigating the interaction between the bulk solid and the conveyor belt during transportation. The research involved simulated laboratory experiments and tests on a moving belt conveyor where the pressure acting on the surface of the conveyor belt through interaction with the bulk solid was measured. The experimental results are compared with existing theoretical methods and to simulations undertaken using the Discrete Element Method (DEM).

E

arly work in the area of conveyor belt and bulk solid interactions during transportation was undertaken by Behrens. This work involved measurement of the reaction loads on conveyor idler rolls during transport for a range of bulk solids and idler roll troughing angles. Behrens showed that the forces on the inclined sides of the belt are in the order of 1.2 to 1.9 times greater than gravity acting alone. Experiments showed a value of 1.2 for a 30o troughed idler roll and 1.9 times for a 45o troughed idler roll.

Similarly, Behrens stated that the normal force acting on the centre idler roll is approximated by the weight of the volume of the bulk solid located directly above. It is important to note that Behrens measured the forces due to both the bulk solid and the belt on the idler rolls, while the results presented herein are for the loading related to the bulk solid only.

Krause and Hettler applied a modified version of Coulomb’s earth pressure theory to calculate the normal forces acting on the side idler rolls of a three-roll idler set. Mulani also applied the modified Coulomb method and considered the convex curvature of the top surface using Rebhann’s graphical analysis, rather than a straight inclined surface. Figure 1 details the force analysis developed by Krause and Hettler for the active stress state due to the opening of the conveyor belt.

Krause and Hettler provided an analysis of the total force acting on the idler rolls as a result of the formation of active and passive stress states within the cross-section of the bulk solid material. The active pressure factor for the opening of the conveyor belt Kca, is expressed in formula 1.

Where fw is the friction angle between the bulk solid and

1

the conveyor belt and fi is the internal angle of friction of the bulk solid. The passive pressure factor for closing the conveyor belt Kcp, is given in formula 2.

The normal force per unit length Fsn, acting on the inclined side of the belt (side idler roll) due to the bulk solid is:

3

Where ρ is bulk density, Lss is the length of bulk solid in contact with the inclined side of the conveyor belt, and the active and passive stress states are assumed to act over half the idler spacing.

The introduction of wall friction fw at the belt and bulk solid interface using Coulomb’s method modifies the stress field at the boundary, however in the analysis its effect does not propagate through the bulk solid. In reality the effect of wall friction at the boundary does propagate through the bulk solid and rotates the principal stress directions.

As a result the stress field is not uniform and the plane of failure is curved (Craig Terzaghi and Peck). In the active stress state the curvature is small and the error involved in assuming a planar surface is relatively minor. This also holds true in the passive case for values of fw<fi/3, however, for higher values of fw like those in typical belt conveying applications, the error becomes large. For this reason, the theory generally will overestimate the total passive thrust.

Mulani applied Rankine’s earth pressure theory to calculate the normal forces acting on a three-roll idler set due to the influence of the bulk solid. Figure 2 shows the Rankine pressure theory applied to a conveyor cross-section for the purpose of calculating the normal forces acting on the side idler rolls for both the opening and closing conditions. Like Krause and Hettler, the side thrust due to the opening and closing of the conveyor belt sides were modelled as active and passive states respectively.

Application of the side thrust calculated by the Rankine method is only applicable to vertical surfaces, and consequently the applied pressure is said to act along a plane perpendicular to the idler junction. Also, to simplify the analysis, the bulk solid surcharge angle directly above the idler junction j, is assumed to be sufficiently small so that j  0.

To calculate the net force acting on each of the side idler rolls, Mulani assumes that the active stress state acts over 2/3 of the idler spacing and the passive stress state acts over the 1 remaining /3 . Mulani also postulates that the passive stress state is not fully developed due to insufficient deflection of the bulk solid, and a value of 85% of the calculated passive pressure factor Kcp for the conveyor is used. The effective pressure factor for the conveyor Kce, is therefore expressed as: 4

2

The normal force acting on a side idler roll due to the conveyed bulk solid is then given in formula 5.

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BELTCON

of the rig and photographs showing the experimental setup is shown in Figure 3.

A range of different bulk solids were tested in the rig, including river sand with a particle size range of 1 to 6 mm and gravel with a particle size range of 5 to 30 mm. A typical test involved oscillating the rig at a frequency of 2.5 Hz and a stroke of 12 mm for a period of 100 seconds during which data is continuously recorded.

In addition to laboratory measurements, the Discrete Element Method (DEM) was used to simulate the loads on the belt surface during oscillation. The DEM software ‘Rocky’ was used to simulate the bulk solid movement.

The results presented are for either 5 or 10 mm mono-sized spherical particles, although the research work has investigated a range of particle sizes and size distributions. The spherical particles were packed onto a cross-section of the belt resembling that of the test rig, with a typical DEM model shown in Figure 4.

Results from gravel and riversand experiments; Krause and Hettler’s analytical analysis; and the DEM simulations are presented for in Figures 5 and 6 respectively. In Krause and Hettler’s method, the calculated normal forces acting during the opening and closing cycle, Fsna and Fsnp respectively, are represented as a linear pressure distribution concentrated at 1/3 Lss, where Lss is the length of bulk solid in contact with the inclined side of the conveyor belt.

Figure 1. Force distribution during opening on side idler roll resulting from the bulk solid (active stress case)

Where Pc is the percentage of bulk solid cross-section over the centre idler roll and Zj is the height of the bulk solid at the idler junction. The net shear, or axial force Fsa, acting on each side idler roll exerted by the conveyed bulk solid material is therefore derived as shown in formula 6.

A disadvantage in the application of Rankine’s theory for calculating the forces acting on the idler rolls is the constraint that the resultant force on the vertical plane acts parallel to the uppermost surface of the bulk solid. Thus, the friction angle for the belt and bulk solid interface must be assumed to be equal to zero.

Laboratory test facility

Experimental work involved the use of an oscillating laboratory test rig that simulated the opening and closing of the belt and enabled the pressure acting on the belt surface to be measured using a pressure sensor.

A 1.5 mm thick layer of insertion rubber covered the sensor to maintain similar friction characteristics to the belt cover surface. The test rig consisted of a fixed horizontal base and two pivoting side sections. The sides were attached to a frame (via turnbuckles) fixed to an oscillating plate.

As the plate oscillated up and down, the sides pivoted. Two transparent walls were fixed at either end allowing for the shear planes to be observed during the experiment. An illustration

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The results indicate a good overall correlation between the measured values obtained from the DEM simulation and the theoretical estimate given by Krause and Hettler for the active stress state (belt opening). For the passive stress state (belt closing), the measured and DEM results are lower than the theoretical values predicted by Krause and Hettler. This is most likely due to two reasons.

Firstly, as noted earlier, Coulomb’s method effectively modifies the stress field at the boundary, however in the analysis, its effect does not propagate through the bulk solid.

Secondly, due to the relatively small transverse movement (small pivot angle) of the bulk solid, the passive stress state is not likely to be fully developed within the cross-section of the bulk solid.

Moving conveyor belt experiments and simulations

In addition to the experimental work undertaken on the small scale laboratory test rig, experiments were also undertaken on a 60 m long recirculating belt conveyor facility at Tunra Bulk Solids. The system selected for this research work consisted of a 600 mm wide PN300/2 belt with a 35o offset idler troughing profile. The sensor pads were used to measure the pressure distribution across the width of the moving belt.

5

Experimental - sensor pressure measurements

6

A 1.5 mm thick layer of insertion rubber covered the sensor

The pressure exerted by the bulk solid on the conveyor belt during transportation was measured using a pressure sensor pad located on the belt surface.

BELTCON

ments involved loading the belt with gravel for a distance of twice the idler roll pitch and measuring the belt profle for a range of sag ratios.

The experimental set-up of the Faro 3D laser scan is shown in Figure 8 in addition to a typical measured belt profile.

Experimental results

A side view obtained from the 3D laser scan in between two consecutive idler roll sets for belt sag of 2% is shown in Figure 9. Also shown is the corresponding loading profile typical to that observed in the pressure sensor tests for the same belt sag.

The 100 mm sections depicted in Figure 9 are positions along the length of the belt related to the following: Figure 2. Rankine pressure theory applied to a conveyor belt cross-section showing both the active (opening) and passive (closing) conditions experienced between idler sets

Figure 3. Oscillating test rig and position of pressure measurement pad

Figure 4. DEM analysis using Rocky

to maintain similar friction characteristics to the belt cover surface and to protect the sensor pad. The experimental setup is shown in Figure 7.

Once the system had been loaded, it was run at a belt speed of 1.5 m/s, in which time 10 seconds of data were recorded.

The bulk solids tested included coal, gravel, magnetite and river sand.

Experimental - 3D laser scan of loaded conveyor belt

A 3D laser scanner was used to measure the profile of the conveyor belt between idler sets. The laser scan measure-

Section A – Immediately prior to the idler roll set Section B – At the centre idler roll Section C – At the side or wing idler rolls Section D – Immediately following the idler roll set Section E – Half of the idler roll set pitch Three tests were conducted for each bulk solid. The transverse pressure profile for each bulk solid was averaged from the pressure sensor tests at each of the five sections: A to E, with the results presented in Figure 10. Also shown in each plot is the calculated hydrostatic pressure (gravitational load) profile, with the normal component calculated for the inclined sides.

From the results presented in Figure 10, similar trends can be observed for all materials tested. Namely, the transverse pressure profile is almost identical at Section A and Section D (before and after the idler roll set) and for these two sections a close correlation to the pressure profile due to gravity alone is also observed.

From Section A to Section B, an increase in the pressure across the centre of the belt is observed, with this value exceeding the gravitational component. This correlates to the material being lifted over the centre idler roll.

The pressure across the centre of the belt then reduces between Section B to Section C as the belt leaves the centre roll and back towards a value close to the gravitational load.

The peak pressure then shifts towards the position on the belt located at the junction of the horizontal and side idler rolls.

The pressure at the centre section of the belt then decreases to lower than the gravitational load, while the peak pressure is maintained at a location on the belt near to the junction of BULK HANDLING TODAY

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BELTCON

the idler rolls. This is shown by the pressure profile measured at Section E. To investigate the load on the conveyor belt that in turn acts on each idler roll, the sum of the bulk solid induced load acting on the inclined side of the belt and the centre of the belt were calculated. This summation was calculated based on the average stress acting on each section from A to E along the length of the belt. The normal force distribution is summarised in Table 1.

Figure 11 shows the force distribution across the belt between the inclined sides and the centre of the belt as a percentage of the total normal force. The results show little variation with the internal angle of friction of the bulk solid material. The ratio of the force distribution between the inclined sides of the belt and the centre section of the belt is approximately 35:65.

DEM simulation of a moving conveyor belt

The scanned 3D belt profile was used to determine the boundary conditions for the Discrete Element Method (DEM) analysis. Utilising a measured belt profile improved the accuracy of the DEM analysis as a result of the relatively

large deflection of the loaded belt.

The scanned cross-sectional profile obtained from the 3D laser scan of the conveyor belt test facility at the idler roll set, and half the idler pitch, is shown in Figure 12. The belt profiles were taken directly from the 3D laser scan image.

Data obtained from the laser scan was used to obtain x-y co-ordinates of the transverse belt geometry. The results for the scanned image in Figure 12 are plotted in Figure 13.

The belt was analysed as 28 individual boundaries, each assigned translational and rotational motion parameters (in the x-y plane). Each boundary moved independently, their collective profile changing from a troughed shape at the idler set, to a curved shape at one half of the idler pitch. This is illustrated in Figure 14 with the nominated x and y direction being positive.

The period of motion was set to 0.4 s corresponding to a belt velocity of 1.5 m/s and idler pitch of 1.2 m. Due to symmetry, only one half of the cross-section was modelled consisting of a longitudinal length of 50 mm and frictionless boundaries located in the centre and at each end of the belt.

(a) Belt Opening (b) Belt Closing Figure 5. Gravel – pressure sensor measurements vs DEM and Krause and Hettler’s method

(a) Belt Opening (b) Belt Closing Figure 6. Riversand –pressure sensor measurements vs DEM and Krause and Hettler’s method

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Bulk Solid

Normal Force on Each Side (N)

Normal Force on Centre (N)

Coal

73

286

Gravel

120

498

Magnetite

191

693

Riversand

126

507

Table 1. Normal force distribution for 24 mm belt deflection (2% sag) â&#x20AC;&#x201C; pressure sensor results

The sum of normal forces exerted by the bulk solid on each of the boundary elements was analysed and averaged over a simulation time of 8 s. The bulk solid materials were modelled as 5 or 10 mm mono-sized spheres using the DEM software.

Coal and riversand were modelled with 5 mm diameter particles, while the gravel and magnetite were modelled with 10 mm diameter particles. The DEM software input parameters were selected on a range of calibration tests, in conjunction with the oscillating test facility results.

Load distribution

The transverse load profiles were summed along the length

of the belt for one idler pitch and are presented in Figure 15 for each of the materials tested. Good correlation between the transverse load profiles obtained from the DEM and those obtained from the pressure sensor results can be observed.

Reduced scatter was evident from the DEM simulations undertaken with smaller diameter particles, namely coal and river sand.

The sum of the bulk solid induced load acting on the inclined side of the belt and the centre of the belt were calculated from the transverse load distribution. The forces are presented in Table 2. Note these forces do not include the weight of the belt.

Coal

Normal Force on Each Side (N) 64

Normal Force on Centre (N) 207

Gravel

118

397

Magnetite River sand

190 132

534 428

Bulk Solid

Table 2. Normal force distribution for 24 mm belt deflection (2% sag) â&#x20AC;&#x201C; DEM results

Figure 7. Experimental set-up to measure belt surface pressure during transportation

Figure 8. 3D laser scanner set-up and typical scanned belt profile

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BELTCON

Figure 16 shows the force acting on the belt at the inclined sides and the centre of the belt as a function of the total normal force. The results are presented as a function of the internal angle of friction of the bulk solid.

The results in Figure 16 show the force distribution between the inclined sides of the belt and the centre section of the belt is constant across the range of bulk solids analysed. The ratio of the force distribution between the inclined sides of the belt and the centre section of the belt is approximately 40:60.

Influence of belt sag

To investigate the belt deflection profile in relation to other belt sag values, additional 3D laser scans were performed at 1.3% and 2.7% sag (16 mm and 32 mm belt deflection). The results from these scans are shown in Fig 17. The initial 2.0% (24 mm Figure 9. Typical pressure sensor results shown in relation to the measured belt deflection) sag profile is once again shown for belt profile at 2% sag comparison purposes.

(a) Coal (b) Gravel

(c) Magnetite (d) River Sand Figure 10. Pressure sensor transverse profiles

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motion

(a) DEM analysis boundaries

Figure 11. Force distribution as a function of internal angle of friction â&#x20AC;&#x201C; pressure sensor results

(b) Belt deflection between idler set and at half idler pitch Figure 14. DEM model Figure 12. 3D Laser scan belt profile for 2% sag

When comparing the deflection geometry of the belt from the troughed shape at the idler set to the curved profile at one half of the idler pitch, it is clear that the belt sides do not pivot about the idler junction. All belt sag images clearly show that the sides of the belt are more likely to pivot about the edges of the belt.

This motion is contrary to the theoretical analysis proposed

by Krause and Hettler, which assumes that the inclined sides pivot around the idler junction. Clearly the transverse deflection of the belt is a function of the transverse belt stiffness and varies depending on the characteristics of the conveyor belt.

Data obtained from the laser scan of the belt with 32 mm sag presented in Figure 17 was used to obtain x-y coordinates of the transverse belt geometry; the results are presented in Figure 18.

Analysis boundaries were developed from the x-y coordinates of the belt geometry, and in a similar manner to that described previously, the process of opening and closing the

belt was modelled using 28 analysis boundaries within the DEM software. The general trends of the transverse loading profiles observed were very similar to results for the 24 mm sag. Results in Table 3 show the normal force on the inclined side and on the centre of the belt.

When compared directly to the 24 mm belt deflection data presented in Table 2, there is very little difference in the normal forces exerted on the belt. Similarly, the distribution of the forces acting on the inclined sides and centre section of the belt remained the same at 40% and 60% respectively.

To investigate the influence of sag further, a comparison of the normal force variation during an opening and closing cycle was also undertaken. Once again the 24 and 32 mm sag data was analysed, focussing specifically on coal and magnetite since their relative particle densities are the smallest and largest respectively. Figure 19 and 20 show the normal force variation on the inclined side and centre of the belt for the duration of the simulation.

During the opening and closing of the troughed shape, the vertical displacement of each of the boundary elements will be greater with increased belt sag. It is evident from the results presented here that the amplitude of the force between the open and closed belt positions is greater with the increased belt sag of 32 mm. This implies a greater amount of work resulting in more energy. This supports earlier work by Behrens, Mulani, Spaans, Nordell and Wheeler.

Comparison to Krause and Hettlerâ&#x20AC;&#x2122;s analytical approach Figure 13. Plot of belt cross-sectional profile from laser scan for 2% sag

The theoretical approach of Krause and Hettler was applied to calculate BULK HANDLING TODAY

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(a) Coal

(b) Gravel

(c) Magnetite

(d) River Sand

Figure 15. Pressure sensor measurements compared with DEM results

the loading on the inclined sides and the centre section of the belt. This theory assumes the active and passive stress states are fully initiated in the bulk solid with the results being essentially independent of belt sag. The results are summarised in Table 4.

Bulk Solid Coal Gravel Magnetite River sand

Normal Force on Each Side (N) 66 119 194 140

Normal Force on Centre (N) 204 406 533 414

Table 3. Normal force distribution for 32 mm belt deflection – DEM results

Figure 21 shows the force distribution between the inclined sides and the centre of the belt as a function of the bulk solid’s internal angle of friction. The results show a strong dependence on the internal angle of friction, unlike the pressure

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Bulk Solid

Normal Force on Each Side (N)

Normal Force on Centre (N)

Coal

283

92

Gravel

290

380

Magnetite

349

484

River sand

200

403

Table 4. Normal force distribution – Krause and Hettler

sensor and DEM results. The ratio between the total normal force acting on the inclined sides and the centre of the belt increases with the increasing angle of internal friction.

The primary reason for the heavy dependence on the internal angle of friction is to facilitate the calculation of the passive pressure factor for the closing of the conveyor belt, Kcp, given in Equation 2. However, experimental data shown in Figure 5(b) and 6(b), as well as the moving belt tests, support the

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(a) Inclined Side Figure 16. Force distribution as a function of internal angle of friction â&#x20AC;&#x201C; DEM results

(a) 1.3% sag (16 mm belt deflection)

(b) 2.0% sag (24 mm belt deflection)

(b) Centre Figure 19. Coal â&#x20AC;&#x201C; normal force as a function of time

(c) 2.7% sag (32 mm belt deflection) Figure 17. 3D laser scans of belt profiles for various sag ratios

theory that the passive stress state is not fully developed in the bulk solid during closing. This is primarily due to the relatively small angle of deflection; while for the moving belt tests, the sides tend to pivot about the edges, rather than around about the idler roll junction as assumed in the analytical approach.

Figure 18. Plot of belt cross-sectional profile from laser scan for 32 mm belt deflection

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On the basis of these findings, a reduction factor was applied to the passive pressure factor, Kcp for the closing of the conveyor belt. The factor is dependent on the internal angle of friction of the bulk solid. For free flowing to moderate to handle bulk solid materials with internal angles of friction up to 45o, a value of 0.4 was found to be suitable, while for bulk solids with an internal angle of friction over 45o, a value of 0.2 was selected. Table 5 shows the calculated normal forces acting on the inclined sides and the centre of belt, utilising the proposed reduction factor.

The force distribution between the inclined sides and the centre of the belt as a function of the internal angle of friction of the bulk solid are shown in Figure 22.

It can be observed that the results plotted in Figure 22 are in much better agreement with the pressure sensor results presented in Figure 11 than those without the use of the

(a) Inclined Side

Bulk Solid

Normal Force on Each Side (N)

Normal Force on Centre (N)

Coal

74

248

Gravel

152

488

Magnetite

181

626

River sand

117

484

Table 5. Normal force distribution – Krause and Hettler (0.4K cp for f i  45 o else 0.2K cp)

reduction factor. Closer agreement with the DEM simulation results is also evident in comparison to Figure 16.

This paper has been condensed due to space constraints. It was first presented at Beltcon 17 in 2013. The authors are Dusan Ilic, Craig Wheeler and Daniel Ausling from Tunra Bulk Solids Research Associates, The University of Newcastle, Australia and copyright is vested with the IMHC. www.beltcon.org.za

(b) Centre

Figure 20. Magnetite – normal force as a function of time

Figure 21. Force distribution as a function of internal angle of friction – Krause and Hettler

Figure 22. Force distribution as a function of internal angle of friction – Krause and Hettler (0.4K cp for f i  45 o else 0.2K cp)

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► EIA Process

► Environmental Risk Assessments

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► Agricultural Assessment and Advise

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N2 Mnini ECO Duties

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Site assessment Sundumbili pipeline

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Skills on Site

Septmeber 2012

1

POWER TRANSMISSION

Improving Motor Efficiencies

Members of the SAIMH and CMA at a joint forum hosted by Zest

Initial procurement and installation of variable speed drive electric motors makes up a very small part of the overall cost of ownership and long term operation of equipment.

Y

et, decisions made at the time of procurement need to be lived-with for years to come and small inefficiencies or unreliability may end up costing companies in the long term. This is according to Kirk Moss, project engineer on medium voltage drives for Zest. Kirk addressed a recent joint forum of the South African Institute of Materials

Handling (SAIMH) and the ConveyorManufacturers Association of South Africa (CMA) on high efficiency motors and variable speed drive controls.

His delivery of an insightful technical presentation gave industry professionals an insight into some of the smaller details that can have a big impact on operational efficiencies and gave insight into future

2.00

1.80 â&#x2C6;&#x2020;T â&#x2C6;&#x2020; motor (p.u.)

T = 1.01*n2 - 2.11*n + 2.10 1.60

1.40

1.20

1.00 0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

Fan speed (p.u.)

Temperature rise x fan speed at rated load At low speeds (reduced ventilation) motor heat rise is substantially increased

Kirk Moss, project engineer on medium voltage drives at Zest

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POWER TRANSMISSION

design skill to achieve improved efficiency. Moreover, efficiency cannot come at the cost of reliability. Zest, for example, has found efficiency through designing motors with vastly improved steel quality, double-layer windings, optimised air-gap, better insulation and other design improvements that enable motors to produce the required output more reliably and with substantial improvements in efficiency.

“At the same time legislation overseas keeps driving improvements and many of these are incorporated into the new SANS/ IEC 60034-30 specification that is being adopted by the South African industry,” Kirk adds.

Use of the Optimal Flux function substantially decreases losses across the speed range

Despite all the design excellence taking place at the top end of the electric motor market, severe losses can still be experienced through factors other than the motor, such as mechanical losses in the drivetrain Identifying losses

However, he cautions, despite all the design excellence taking place at the top end of the electric motor market, severe losses can still be experienced through factors other than the motor, such as mechanical losses in the drivetrain. Over or under specification of motors can also play havoc on the overall efficiency of a system.

“Firstly we remind users to correctly specify motors to between 70-90% of load requirements without being overly cautious by The result of optimal flux is a vastly improved torque capability at low speeds of self-ventilated working in too many safety factors. motors Next to look at the mechanical operation in terms of the transmission and coupling trends that will have an impact on the materials choice and to ensure that these match the efficiency handling industry. of the overall system. Then, look at the VSD where Getting it right losses can also occur. Although it’s too complex to “Essentially there is nothing new about electric go into full detail here, it’s important to know that motors and they have been designed and rede- losses of about 1-2% at 50Hz can occur. signed hundreds of times over. So companies go to “Stay aware of the fact that at low speeds the temgreat lengths to gain just a one or two percentage perature of a motor rises due to the decreased coolimprovement in efficiency of an electric motor. ing effect of the self-ventilated motor, resulting in a “To find the smallest of improvements in consump- torque de-rating occurring at lower speeds. Separate tion and output is critical and takes the utmost force ventilation is required to maintain constant

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POWER TRANSMISSION

The magnets generate their own magnetic field without the need for induction of currents.

There are no iron and Joule losses on the rotor

constant flux, the application of the optimal flux control method dynamically varies the flux through the speed range to minimise losses.

The result is an almost constant torque from the motor, even at low speeds and without the need for force ventilation.

It’s important to know that losses of about 1-2% at 50Hz can occur New generation motors

torque across the speed range. A unique control method called optimal flux can be implemented when using high efficiency motors in combination with VSDs, which results in substantially lower losses at lower speeds,” Kirk advises.

Optimal flux

Kirk concluded his presentation by advising that the latest controls and techniques in the right application contribute to significant savings to the customer across the entire operation.

Zest, Kirk Moss, Tel: (011) 723-6000, www.zest.co.za

FCB CAPE TOWN 10008448CT/E

“Torque depends on flux or the strength of the magnetic field, so while a VSD normally provides

“Permanent magnet motor technology, although around for some time, is becoming increasingly viable economically,” Kirk continues. This technology allows smaller motors to be used for the same power output, an example being Zest’s WMagnet motor and drive which substantially improves efficiency while reducing motor footprint. The motors are specially manufactured to be used with VSDs and the range covers applications from 11kw upwards.

Keeping Africa running smoothly.

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Contact the Engen Customer Service Centre (CSC): +27 21 403 5090 or visit www.engenoil.com.

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A Window into Bauma Conexpo Local Industry Africa 2015

Many major players in the industry have already signed up to exhibit at Bauma Conexpo Africa.

This international trade fair takes place from 15-18 September 2015 at the Johannesburg Expo Centre (JEC).

“

Bauma Conexpo Africa serves as an excellent opportunity to unveil our new Cat equipment technologies and earthmoving solutions to our Southern African mining, onstruction and industrial customer base,” says Samantha Swanepoel, general manager of marketing at Barloworld Equipment.

The Industrial Showcase-Cape has a successful track record dating back to the mid-1980s and includes exhibitors covering almost every conceivable product or service in the industrial space.

A

verage attendances over the years have exceeded 3 000 focused prospects. Research among those attending indicates that 67% either recommend or have final decision-making authority over industrial purchases in their organisation. Another interesting statistic is that 68% are in management or are owners.

Gary Bell, CEO of Bell Equipment, adds, “Geared at two of our major sectors, construction and mining, this expo is a prime opportunity to showcase our company as the continent's home-grown, one-stop shop for quality equipment solutions. This event promises to build on the inaugural show by attracting more industry role players and generating positive spin-offs for the region, the industry and our customers.”

Other major players have also signed up, among them, for the first time, are Case Construction, Deutz Dieselpower, MTU, New Holland Construction, Scania, Ulma and WACO. The excellent uptake by major companies is matched by a high level of interest from abroad: So far, nine countries and regions are planning to organise joint presentations of exhibitors at the show. These are: China, Finland, France, Germany, Italy, North America, Spain, the UK and the Walloon Region.

Bauma Conexpo Africa, www.bcafrica.com

Exhibitions remain a great forum for interaction with potential and existing customers. In spite of the advances made with online shopping, the role of face-to-face selling can never be underestimated for industrial products.

However, the visitor profile also includes production, maintenance and factory managers who are also great influencers when it comes to choosing specific products or services.

In addition to the static displays, there will be a dedicated speakers’ area at this year’s show where daily presentations on a host of interesting topics will take place. The show takes place 1-3 July 2015 in Cape Town. www.industrialexpo.co.za

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POWER TRANSMISSION

Fundamental to Equipment Reliability “Equipment reliability is the proverbial golden egg for any plant, quarry or mine because uptime, production and productivity levels all hinge on uninterrupted operation,” says Bearings International (BI) sales director, Shuttleworth Ntsie. “But it goes one step further because the reliability of equipment that operates under extreme conditions like crushers for example, is determined by the quality of its components.

“

This is where premium brands take centre stage, offering world-class quality and the latest technology through ongoing R&D by the respective OEMs.”

for conveyors. Schaeffler has been the OEM for the Fag premium brand for over 100 years and the products are designed to offer best possible cost-to-performance ratios.

BI excels when it comes to arduous applications like crushing where poor control of product flow or ‘heave’ after blasting can lead to oversized boulders being fed into primary crushers which can badly affect efficiency and reliability with a knock-on effect on production. “Lump sizes larger than between 0,5 and 1,0m can cause crushers to jam, reducing the life of components such as bearings,” explains Coenie Van Deventer, national product manager – Schaeffler Bearings Products at B.

The Fag range covers 60 industrial sectors and a staggering 225 000 applications. For main bearings in jaw crushers, Coenie recommends Fag E1 spherical roller bearings in X-life quality which have been especially engineered for extremely heavy loads and are used wherever angles must be adjustable.

They work reliably under tough ambient conditions, delivering up to 70 % longer service life.

They work reliably under tough ambient conditions, delivering up to 70 % longer service life “Schaeffler’s quality range of Fag roller bearings and SNS housings are central to the smooth running of equipment at mines and quarries such as primary, secondary or tertiary crushers that are subject to continuous impact loading as well as

Advantages such as high static reliability, lower strain on the lubricant due to reduced friction and low bearing temperatures translate to higher machine efficiency and reduced operating costs for the end user.

Arduous applications

Fag spherical roller bearings are also the premium solution for conveyors at crushing sites and Fag’s split spherical roller bearing solution is recommended to speed up bearing replacement, particularly in difficult-to-access areas. Coenie explains, “The unique design of the split spherical bearings allows for quick and simple mounting and replacement of bearings which can significantly reduce downtime and associated costs. We also offer housings solutions for arduous crusher applications. Fag’s new SNS housing range extends the life of bearings on conveyor drives and are manufactured from high impact tough, fatigue resistant, high-specification SG50 (spheroidal graphite) cast or ductile iron.”

In addition to higher load ratings and longer life, the optimised housing design ensures a more even distribution of load through the bearing which according to Schaeffler, can increase bearing life by more than 50%.

The new housing also provides a very high sealing efficiency against the ingress of contamination of foreign matter. “These housings are 100% compatible and interchangeable with any conventional plummer block solution,” adds Coenie.

Condition monitoring

FAG's new SNS housing range for arduous crusher applications

Turning to after-sales service, he highlights that reliability engineering, which involves the specification of the right product to best suit the required operational reliability as well as the monitoring of the product’s condition and performance in the BULK HANDLING TODAY

April 2015

37

POWER TRANSMISSION

No-one can afford a plant to stand due to equipment failure which involves production losses due to unplanned downtime and costs for maintenance and replacement parts

Connected via Ethernet to a computer network or an onsite remote router station, SmartCheck consists of a permanently-installed vibration sensor that remotely monitors lubrication levels and bearing condition on an ongoing basis. The system enables the condition of a bearing or gearbox or any rotating component to be accessed wirelessly on smartphones or tablets.

Premium is prime

Wrapping up, Coenie stresses that the higher investment cost of a premium brand component is minimal if weighed against increased uptime and component and equipment life. “No-one can afford a plant to stand due to equipment failure which involves production losses due to unplanned downtime and costs for maintenance and replacement parts.”

FAG spherical roller bearings engineered for extremely heavy loads

field, is without doubt the smart way to go.

Bearings Products at Bearings International Coenie van Deventer, Tel: (011) 899-0101 Email: coenievd@bearings.co.za

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Condition monitoring can safely extend component life beyond L10 and provide early warning of imminent failure so that timely action can be taken to prevent catastrophic failures and costly unplanned downtime. Fag recently launched a condition monitoring solution for bearings called SmartCheck.

The company’s premium brand product range covers general and specialist bearings and accessories; transmission and conveyor chains; gearboxes and geared motors; electric motors and variable frequency/speed drives; couplings, pulleys, vee- and wedge-belts; oil seals, conveyor belts, industrial hoses as well as industrial adhesives, hand cleaners and lubricants for a wide spectrum of applications across mining, quarrying, general industry and agriculture.

Protect Your Belt Conveyors with Voith Fluid Couplings.

The Voith Fluid Coupling, type TVVS, is predominantly used in belt conveyor drives.

The coupling protects the drive against overload and dampens torsional vibrations. This protects your system and increases its productivity.

Key Benefits: • Very smooth start-up • Torque limiting up to 140% of nominal load • Automatic adjustment to different load states info.vtza@voith.com Tel: +27 11 418 4000 www.rsa.voithturbo.com

38 V14727 BULK HANDLING TODAY April Voith MM Bulk Handling HP DH3 FEB15.indd 1

2015

2014/12/10 2:37 PM

QUARRIES

Mosh Practices Not for Everyone A one-size fits all approach to eliminating fatalities on mines is not necessarily useful unless proper studies are undertaken across the full spectrum of mines and quarries in particular focus areas.

T

his is according to Letisha van den Berg, regional chairman of the Aggregate and Sand Producers Association of Southern Africa (Aspasa) in response to proposed leading practices that are being mooted by the Mine Occupational Health and Safety (Mosh) Council.

Mosh is focusing on finding solutions to particular problem Letisha van den Berg, regional chairman of the Aggregate and Sand areas on our mines. Recent Producers Association of Southern findings that proportionately Africa (Aspasa) more fatalities are caused by trackless mobile machinery (TMM) on smaller mines, sparked Mosh studies of smaller mine accidents but did not necessarily focus on quarries.

used in quarries is very different from those which are the subject of the studies. For example, fewer machines operate in typical quarries and the sizes of these machines tend to be smaller than on typical mines. Therefore operators are more aware of their surroundings and can more easily detect objects in their work area.

She adds that without input from the aggregate and sand industry, the Mosh leading practices are not objective and should be reassessed or separate studies undertaken for certain quarries

Underground studies

“Retrofitting these devices is expensive and we are not convinced that they will work in our environment. For example, if an operator relies too much on his PDS, and it becomes faulty, he may cause an accident. Or if the warning buzzer of his CAS gets too irritating, he may switch it off or may chose to disable his MI in order to speed up his operation,” Letisha adds.

“However, the number and types of machines

“In this way, a false sense of security is created for workers and they may relax their attitude towards equipment and vehicles. We would rather advise that our member mines trial these units to ensure they work correctly before buying to avoid additional costs. They should also visit operations that have similar installed units to see the systems are having the desired effect,” says Letisha.

“The resultant “leading practices” that have been formulated are therefore based on small mainly underground, as well as coal mines. Research indicates that proximity detection systems (PDS), Collision Avoidance Systems (CAS) and motion Inhibitors (MI), among others, would reduce accidents.

Vehicles on quarries

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QUARRIES

May be legislated

She adds that without input from the aggregate and sand industry, the Mosh leading practices are not objective and should be reassessed or separate studies undertaken for certain quarries.

If the leading practices are deemed a success, then they may be promulgated to become law that all mines will have to abide by.

Aspasa and other small mines want the Mosh study to be expanded to include input from quarries.

These include the physical structure, operating procedures and practices of these operations, and budgetary constraints faced by some of the smaller quarries.

The potentially costly and cumbersome nature of the systems being proposed will be hard for small family run-type operations to abide by and may not prove to be as effective as simpler, industry-defined measures that can easily be implemented and managed.

If the leading practices are confirmed and accepted, we will be left out in the cold Adding their voice

“In previous Mosh meetings, we proposed that Aspasa and small mines rather adopt new practices whereby a risk assessment must be conducted to indicate the level of risk and what type of control measures would be sufficient.

Interventions such as the introduction of a traffic management approach may be sufficient, whereby we separate different sizes and types of vehicles and equipment to avoid accidents. Also by separating pedestrians from equipment and vehicles, we can limit exposure and effectively avoid pedestrian fatalities,” Letisha comments.

Clouded thinking

“Another effective measure than can be implemented is managing fatigue of both operators and workers alike. By making them aware of the dangers of over-tiredness, we can reinforce safer working practices and prevent the types of accidents we commonly see as a result of clouded thinking or falling asleep at the wheel of a machine.

“My concern is that Mosh has started inviting us to their workshops but not to the feedback sessions from industry nor are we being kept informed of the progress of these trials. We have not been invited to the next round of Mosh talks and if the leading practices are confirmed and accepted, we will be left out in the cold. We therefore appeal to Mosh and to the Mine Health and Safety Council to refrain from adopting a one-size-fits-all approach to safety on our mines and quarries,” concludes Letisha.

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

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MARKET FORUM

Realistic Data

DEM Solutions (Discrete Element Method) specialists in Scotland has developed and launched a co-simulation capability that could revolutionise how engineers approach the design of equipment that handles bulk materials.

DEM Solutions has worked with Ansys, an innovator of engineering simulation software, to develop a co-simulation capability enabling engineers to access Edem bulk materials simulation data directly within Ansys Workbench, allowing high-quality representations of bulk materials and their complex behaviour to be included in Finite Element Analysis (FEA).

The new ‘EDEM Add-In for ANSYS Workbench’ introduces a streamlined process to transfer material load data and will give equipment designers and manufacturers access to EDEM data in the familiar Workbench environment.

The major benefit of the new capability is that it removes any guesswork by giving design engineers the data on the pressures and forces caused by the bulk materials acting on the equipment.

Manufacturers of equipment designed to handle bulk materials, such as bucket loaders, transfer chutes and truck bod-

ies, must take into consideration the behaviour of materials such as coal, ores or soil. Previously, this has been complex and difficult to predict using traditional methods. Estimating the effect of material loads on equipment can significantly impact the success of the product design.

To gain insight into the structural integrity of any proposed design, engineers routinely use CAE tools such as FEA. This approach can be relied upon to provide accurate analysis of the structure; however, the effect of interaction between the structure and bulk material which the equipment is designed to handle is a significant approximation which can only be confirmed by time-consuming and expensive physical prototype testing to

ensure the design meets requirements.

Shane Moeykens, senior partnerships manager of Ansys says, “This development will complete the picture for design engineers in providing a detailed understanding of the effect of materials on equipment design, allowing improved design accuracy and greater insight into equipment performance. In addition, the cost of expensive physical prototyping and days of reliance on assumption and guesswork will be reduced.

“By coupling Edem with our Ansys Workbench, equipment designers can access multiple tools in a quick and easy environment.”

DEM Solutions,, www.dem-solutions.com Email: info@dem-solutions.com

Controller for Mobile Machines ifm electronic’s Ecomat Mobile is an ExtendedController for complex control functions in mobile machines. In addition to the multifunctional inputs and outputs, each control module is equipped with five CAN interfaces. They support all important bus protocols, different baud rates and also the transparent and preprocessed data exchange. Programming to IEC 61131-3 ensures that all control functions can be easily integrated in the application programme.

The control electronics integrated into a compact metal housing provides all necessary connections for the inputs and outputs, communication and programming via the reverse-polarity protected central plugs suitable for mobile applications.

The RGB status LED displays the most important system messages.

The core of the controller is a modern 32-bit processor. Monitoring and protection functions enable safe operation even

under extreme operating conditions. The input / output extension is connected to the main controller via a CANopen interface. By means of the application software, the inputs and outputs can be configured to adapt to the respective application.

Depending on the type of input, a configuration as digital, frequency or analogue input with diagnostic function or as digital input or input for resistance measurement is possible.

In addition, some of the inputs support the evaluation of positive and negative digital input signals. The analogue inputs enable both current and voltage measurement.

Most outputs provide a configuration as

digital or PWM output with diagnostic capabilities, with and without current control. ifm electronic SA, Tel: (012) 450-0370 Email: info.za@ifm.com, www.ifm.com/za

BULK HANDLING TODAY

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MARKET FORUM

West African Shipping SafmarineMPV, which has been a key supplier of seaborne transport services to West Africa for decades, has upgraded its SAFWAF multi-purpose shipping service (connecting South Africa and West Africa) from six-weekly to monthly sailings.

This increased deployment allows the company to provide the trade with both higher frequency and regularity, as well as more extensive port coverage through inducement into the Central West Africa port range (Cameroon to Ivory Coast).

Core ports of call on the SAFWAF service are Walvis Bay, Durban, Cape Town, Sonils (Luanda), Matadi, Pointe Noire and Port Gentil.

SafmarineMPV says the fine-tuning of its SAFWAF service will provide the marketplace with a solid means to capitalise on any growing business opportunities on this key trade route and to do so in various market sectors including agriculture, infrastructure, mining and energy.

Fluid Coupling Drive

Risers shipped from South Africa to West Africa on SafmarineMPV’s SAFWAF service.

The service, which was upgraded from six weekly to monthly sailings as of April 2015, gives shippers in various market sectors, including agriculture, infrastructure, mining and energy, the opportunity to take advantage of the growing opportunities in the West Africa market

The service upgrade takes effect in early April 2015 with the Safmarine Longa Voyage SA 15002.

Drive systems specialist Voith celebrated the manufacture of its 1 000th TPKL fluid coupling, which was recently shipped to China for use on a 6.4 MW underground belt conveyor drive at a coal mine.

The 3.160-m-long belt conveyor is designed for demanding workloads, and will transport coal uphill at a 14o angle. It is driven by four 1 600 kW motors, with a planned capacity of 4 000 tons per hour.

The coupling provides excellent torque limitation for a smooth start-up of the belt conveyor, while allowing active load sharing with multi-motor drives.

Given its rugged design and proven performance, the TPKL fluid coupling is ideally-suited to the harsh African mining sector, which

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April 2015

SafmarineMPV, Tel: (021) 418-2051 www.safmarinempv.com

continues to experience substantial growth year-on-year.

“The TPKL is rich in benefits that ultimately speak to the key business drivers of any major operation and this is where Voith delivers exceptional value. These business drivers include measures such as safety, availability, reliability, production rates and reduced total cost of operation.

“Further peace of mind comes from the fact that we have a qualified service team that can provide on-site support to our customers around the clock,” says Grant Robinson – Voith Vice President for EMEA Division – Mining and Metals Southern Africa.

Voith Turbo Terry-Lynn McIntosh Tel: (011) 418 4000 Email: Terry.Mcintosh@voith.com

MARKET FORUM

If designed and engineered correctly, transfer points play a vital role in increased throughput and productivity

The Diamond Sector

Numerous successful installations of Weba Chute Systems in the diamondmining industry have proved that the correct application of the company’s scientific approach to the dynamics of bulk materials handling can completely eliminate the problems associated with conventional transfer chutes, resulting in significant cost savings in the diamond-mining industry, says founder Werner Baller.

The Weba Chute System is based on the lined ‘super tube’ or cascade system that results from those occasions when material runs on material.

Truckcentricity Road safety, BBBEE, green issues, strike season and the loosely-worded consignor/ consignee legislation are just some of the highlights of this year’s Road Freight Association (RFA) Convention. Themed “Truckcentricity”, this three-day event takes place at Champagne Sports Resort, Drakensberg, KwaZulu-Natal from Sunday 24 May to Tuesday 26 May 2015.

Apart from being specified for longterm refurbishment contracts at some major diamond mines, Weba has also introduced specific innovations for the diamond-mining industry. These include a slurry screen splitter distributor system that allows for a nominal belt capacity of 600 tph, with a water and effluent addition of 1 080 m3/h at a particular diamond mine.

“This was a very interesting application whereby the scrubbing process takes place within the actual chute itself, which was designed in such a manner that it caused a change in direction, resulting in turbulence and therefore a scrubbing action within the material being transferred,” Werner explains. In

RFA Convention is a major highlight on the road freight industry calendar and is the largest gathering of decision-makers in the industry. Its main objectives are to afford members and other industry role-players an opportunity to meet informally, network, gain new knowledge and debate industry-related matters. It also provides a platform for updating the industry on new legislation that could severely impact operations if left unattended.

RFA Convention 2015 will also feature

order to facilitate the scrubbing process, water is introduced at strategic points inside the chute.

Bulk materials handling poses a significant challenge in the diamond-mining industry, where conveyor systems have to deal with belt speeds from 2.5 m/ second to 5 m/second. Warner says they have accumulated significant intellectual capital about “the perfect transfer point”, which includes conveyor to conveyor, conveyor to stockpile and conveyor to screen applications.

M & J Engineering Mark Baller Tel: (011) 827-9372 www.mjeng.co.za

a host of leisure activities including the annual Golf Challenge, a 60s themed Gala Dinner, a Gymkhana, a miniature radio-controlled truck racing event and a full spouses’ programme. It’s important to note that the RFA Convention 2015 is not just a conference, it’s a Convention - with lots of opportunities for both work and play!

RFA Convention 2015, Shantal Singh Tel: (011) 974-4399 Email: events@rfa.co.za www.rfa.co.za

BULK HANDLING TODAY

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MARKET FORUM

Precise Detection Becker Mining South Africa’s recentlylaunched IGBT mine traction battery chargers have been designed to charge underground traction batteries in the shortest possible time, at the lowest possible temperature, to ensure optimum battery performance.

“The most common causes of battery failure and reduced service life are associated with incorrect charging techniques,” says Andrew Trentelman, senior general manager: electronics, Becker Mining SA. “Our new chargers, which utilise insulated-gate bipolar transistor (IGBT) technology for quick on and off switching, are more efficient and costeffective than conventional transductor controlled, oil-cooled traction battery chargers.”

These IGBT battery chargers are lightweight air cooled units, which are controlled by an intelligent micro processor circuit that acts as the main control computer, responsible for the logging, charge functions and controls.

“They utilise Delta Volts/Delta Time (DV/DT) for the precise detection of a battery’s gassing stage so the charger can terminate the second rate charge more rapidly. This technology, which prevents over-charging often associated with conventional battery chargers, ensures reduced charging times and lower power consumption. By reducing the charge current once DV/DT is reached, batteries are charged at a significantly lower temperature,” Andrew concludes.

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Recently launched IGBT mine traction battery chargers have been designed to charge underground traction batteries in the shortest possible time, at the lowest possible temperature, to ensure optimum battery performance

With an improved power factor of 0,8 and a maximum input current which has been reduced from 42 A to 32 A, these energy efficient battery chargers offer power savings up to 10 KVA during maximum output current.

The auto cell detection system enables IGBT chargers to execute a short test charge on every battery to the determine the number of cells connected to ensure correct charging. Other cell configurations and various Amp/hour ratings (100 A/h to 1 000 A/h) can be programmed and stored through the user interface, with no additional changes to the battery charger itself.

For the efficient management of mine traction batteries, Becker Mining’s robust chargers have an integrated power line communication (PLC) identification method, which automatically logs the

April 2015

serial number, as well as the charge history related to that specific battery.

The user interface is a full colour display which provides relevant information, including voltage, current, state of charge, temperature of stack, capacity charged, duration of charge, errors, time and date.

Becker Mining’s IGBT traction battery chargers are equipped with Wi-Fi to facilitate future downloading of data, errors and the charge history of each battery, or for viewing or analysis on the surface.

Becker Mining South Africa offers a technical advisory and support service to mines throughout Southern Africa.

Becker Mining South Africa Andrew Trentelman Tel: (011) 617-6300 www.za.becker-mining.com

MARKET FORUM

Slider Cradles Two conveyor system components have been designed to mitigate expensive spillage and belt wear issues at material transfer points. The Evo slider cradle and the Martin slider cradle both support the belt and prevent spillage due to belt edge sag. Located under the skirt board in the chute box after the impact cradle, the units utilise “double-life” slider bars, which offer a superior seal with low friction.

The slider cradles are designed to mitigate expensive spillage and belt wear issues at material transfer

The result is a flat and stable points belt surface throughout the settling zone, reducing fugitive material and extending belt health.

Transfer points can be prone to spillage as the conveyed material lands on the receiving conveyor. Once the belt leaves the impact cradle, it can sag while the material is still settling. This compromises the skirt seal, allowing dust and fines to escape, while creating pinch points where material can get caught and gouge the belt.

Belt health is a big concern for operators, as edge wear and sagging contribute to misalignment and belt damage, which can also become a potential workplace safety hazard. “Cradles and impact beds are the foundation of our material handling strategy,” says a company spokesman. “Not only are they on the bottom and everything is built on them, but they offer the flat surface to seal against, which is critical in preventing spillage and dust.”

The Martin Engineering slider cradles are designed for conveyor systems with speeds up to 700 fpm (3.5 m/sec) and belts lengths of more than 50 feet (15.2 m). Typically 48 inches (1220 mm) long, the units are also available in custom sizes for special applications.

Martin Engineering, Rick Felde, Tel: (013) 656-5135, Email: rickf@martin-eng.com www.martin-eng.com

Apron Feeder Tenova Takraf Africa has successfully completed the supply of an underground apron feeder to Wessels Mine, part of BHP Billiton’s Hotazel Manganese Mines, in the Northern Cape.

The contract scope covered design, manufacture, delivery to site and assistance with installation and commissioning of a 1 250 mm wide by 6 000 mm long, Model d4 apron feeder. It has a capacity of 500 tph and receives manganese ore of 500 mm maximum lump size to feed to a jaw crusher.

The apron feeder was supplied as a routine replacement of an existing one (also supplied by Tenova) which has been operating successfully at the mine since the 1990s. The new apron feeder features a number of enhancements over the older design, including the use of standard undercarriage parts, which means that spares are readily available and more cost-effective.

A design challenge was to ensure that the size and mass of the apron feeder assemblies were such that they could be easily transported underground via an incline. This was achieved by splitting the frame in two longitudinal sections

without the need to remove the flights or any other parts.

Tenova Takraf Africa, Maurice Malaza, Tel: (011) 201-2300, Email: TMM@tenova.com

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MARKET FORUM

Ensuring their Survival Skyjacks Tailifts and Ratcliff Tailifts have announced that they have entered into a joint venture as at 1 March 2015 that will effectively combine 60 years of tailift knowledge, R&D and manufacture.

The companies will soon move to a single manufacturing facility at SkyPark, in Anderbolt Extension, Boksburg, that has been purpose-built for the manufacture, servicing and fitment of tailifts.

“Given the risks inherent in the uncertainty surrounding the supply of electricity and potential industrial action that saw our steel supply disrupted in 2014, the companies’ directors believe that this joint venture will ensure the survival and growth of the South African manufactured tailift,” says Warwick van Breda,

managing director for Skyjacks Tailifts.

“Our combined existing customer bases, as well as potential new customers, will benefit significantly from the pooled customer support that will provide both on- and off-site support for all brands of tailift. We will also leverage off our combined dealer networks in southern

Africa to enable us to move ahead with a strategy to sell and service our locally produced products internationally.”

Skyjacks Tailifts Warwick van Breda, Tel: (011) 849-6769, Email warwick@tailifts.co.za www.tailifts.co.za

Link-Belt Cranes

Index to Advertisers Manufactured by LinkBelt Construction Equipment, headquartered in Kentucky, USA and a wholly-owned subsidiary of Sumitomo Heavy Industries (SHI) Japan, Link-Belt cranes are based on a rich history of innovation and superior product quality dating back 140 years.

Eqstra Industrial Equipment (EIE) is adding Link-Belt Cranes to its range, following the signing of an agreement giving it the distributorship rights for South Africa and some 17 other countries across Africa.

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BULK HANDLING TODAY

Known worldwide for its telescopic boom and lattice boom cranes, Link-Belt offers the construction industry one of the most diverse line-ups of cranes available. This includes rough terrain cranes (from 30mt to 135mt), telescopic truck cranes (from 36mt to 120mt), truck terrain cranes (70mt and 85mt), all terrain cranes (185 mt and 250 mt), lattice truck cranes (136mt and 272mt) and telescopic crawler cranes (from 51mt to 100mt).

Eqstra Industrial Equipment (EIE), Karen van Diggelen, Tel: (011) 571-0294

April 2015

Afzelia 32 Barloworld Metso

12

Bibby Turboflex

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Bonfiglioli 14 CIS

Inside Front Cover

Engen 35 Hägglunds 16 ILS 30 Kaletsa 40 Melco PowerGen Africa

36 Inside Back Cover

Renold Crofts

40

RFA Convention

20

Scaw Metals Outside Back Cover Tenova Takraf Veyance

18 Outside Front Cover

Voith 38

Log onto www.promech.co.za to read this issue on-line

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BULK HANDLING TODAY

April 2015

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A trusted industry leader For 90 years, SCAW, a South African industry leader, has been a preferred supplier to the lifting and rigging industry.

From wire & strand products, Haggie® Steel Wire Rope, chain products aswell as fittings and attachments, Scaw continues to design and deliver the highest quality products to customer specifications.

Highly qualified teams with extensive experience in all aspects of the application of our products are on call to advise and support the selection, handling, installation and maintenance of products vital to driving safety, productivity and profit in the lifting and rigging industry.

www.scaw.co.za 48

BULK HANDLING TODAY

Proud Manufacturers of Haggie Products & McKinnon Chain

April 2015

Experience Matters.