same: sep 2010

THE SOUTH AFRICAN MECHANICAL ENGINEER VOL 62 September 2010 1

2 THE SOUTH AFRICAN MECHANICAL ENGINEER VOL 62 September 2010

THE SOUTH AFRICAN MECHANICAL ENGINEER VOL 62 September 2010 �

AN ENGINEER’S VIEW

Chris ReayChairman of the Working

Committee: Communications(SA Institution of Mechanical

Engineering)

While the battle between the reductions in fossil based power and nuclear contin-ues with the usual largely misinformed input by the anti-nuclear protagonists,

renewable energy is receiving a lot of attention in the forms of wind, solar, photovoltaic, biogas, wave and hydrogen. In South Africa, overlaying the issue is the impact of the large increases in the cost of traditional fossil-based power created by the lack of vision and unbelievable naïveté displayed by the government in the years following the era in which we had surplus capacity in our fossil stations. Completely beyond comprehension was the belief by government that the independent power producers would suddenly emerge and be prepared to provide power at below cost, and certainly at tariffs that at the time meant a negative return on investment.

When the reality of the situation finally hit home through the load shedding debacle, we were then faced with the challenge of returning to the large “six pack” stations that were the norm for Eskom and which now had to be resurrected hurriedly, the costs of which now meant massive annual tariff hikes that will be substantial for the next five years.

Nero-fiddling playbackThe option of additional nuclear plants such as Koeberg seemed to feature in a sort of Nero-fiddling playback, and then we decided we had to dump the PBMR after spending enormous development costs and creating what must be substantial intellectual property that will, in the true form of these things, never re-emerge other than with competitors who will attract our brainpower.

The next amazing feature of this now manic-level response to the power challenge appears to be another illusion of adequacy in assuming we know how to plan ahead with renewables. One such illusion is the “plan” to have 10 000 GWh per annum of renewable

capacity installed and available by 2013. This is a statement made in August 2010.

Every day of the yearGiven the 28 months left until the start of 2013 by which time the capacity must be installed, com-missioned and connected to the grid which would have to be upgraded to accept intermittent input from diverse locations, then being very optimistic and providing 16 months to set strategy, identify parties, get licences, do the EIAs, design, procure and deliver to a prepared site, we would have 12 months to erect 1425 x 2MW turbines based on a load factor of 20% to compensate for the varied wind blanket. This factor is the maximum the Ameri-cans and Europeans have found possible from wind power. On this basis, we would need to install and commission 1,6 x 2MW turbines every day of the year including weekends and public holidays.

While I believe in ambitious targets, this just makes one wonder who is advising the Minister and just how easy it is to influence non-technical people with illusory numbers. It took the Danes, the most advanced wind power nation in the world, over 30 years to install less than 7000 GWh in their well wind provided environment and with a grid that had been developed to accept the vagaries of renewable supply.

One does wonder who is planning South Africa’s future infrastructure and how many engineering knowledge sources are being consulted or charged with developing such plans. Not once have the pow-ers-that-be approached the SAIMechE to provide input to any engineering based plans.

The uninformed, as Lang said, seem to adopt sta-tistics like a drunk man uses a lamppost, mainly for support rather than illumination.

Electrical energy is the lifeblood of any country’s economy and living standard, and the degree of development must inevitably be linked in direct proportion to

its supply and consumption. With the pressure now growing to minimise the green gas effects of fossil based power generation, the move to renewables is gathering momentum. Added to this is the ongoing dispute over nuclear power generation

that is the only other form of large base-load technology with the exception of hy-dro power that is itself limited by the availability of sufficient water capacity.

The Energy Conundrum

Adopt statistics like a drunk man uses a lamppost, mainly for support rather than illumination

� THE SOUTH AFRICAN MECHANICAL ENGINEER VOL 62 September 2010


Obituary9 PaulineBouwer

MonthlyColumn10VesselsForAfricaFromAfrica

CoverStory13 SaveAir,SaveEnergy

CostEngineering18UnitingDisparateProfessions

Crushers&Screens15 LiningUpForSuccess19 ARevival

POWERGENERATIONTODAY23 PoweredbyNature26 PowerGenerationNews

Produced by:PROMECH PUBLISHING,P O Box 373, Pinegowrie, 2123Republic of South AfricaTel: (011) 781-1401, Fax: (011) 781-1403Email: [email protected]: www.promech.co.zaManaging Editor Susan CustersEditor Kowie HammanAdvertising Susan CustersCirculation Catherine MacdivaDTP Zinobia Docrat/Sean BacherDisclaimerPROMECH Publishing and The South African Institution of Mechanical Engineering as well as any other body do not take responsibility for the opinions expressed by individuals.Printed by: Typo Colour Printing, Tel: (011) 402-3468/9

Official Publication ofTHE SA INSTITUTION OF MECHANICAL ENGINEERINGand endorsed by:

CORROSION INSTITUTE OF SA SA PUMP MANUFACTURERS ASSOCIATION SA VALVE AND ACTUATORS MANUFACTURERS ASSOCIATION THE SA INSTITUTE OF TRIBOLOGY NUCLEAR INSTITUTE SA INSTITUTE FOR NON-DESTRUCTIVE TESTING NATIONAL SOCIETY OF BLACK ENGINEERS INSTITUTE FOR CERTIFICATED MECHANICAL AND ELECTRICAL ENGINEERS SOUTH AFRICAN ASSOCIATION OF CONSULTING ENGINEERS ASSOCIATION OF SOCIETIES FOR OCCUPATIONAL SAFETY AND HEALTH

Oils&Lubrication30 OilingTheWay33 GoodTribologySavesTime

Compressors,AirMotors&VacuumPumps35 NewPlayerInTheAirMarket37 CatchUp

Regulars3 AnEngineer’sView6 InstitutionNews22 SAIT28 NuclearInstitute(SABranch)29 SAINT39 MarketForum46 OntheMove

Contents

The monthly circulation is 4 242

CopyrightAll rights reserved. No editorial matter published in “SA Mechani-cal Engineer” may be reproduced in any form or language without written permission of the publish-ers. 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.

September 2010 VOLUME 62 NUMBER 9

Featured on the cover:

Atlas CopcoTel: (011) 821-9120

Email: [email protected].

com


Council 2010/2011

Office BearersPresident .......................... . . . . . . . . . . . . . . . . . . . . . . . . G Barbic (George)President Elect ........................... . . . . . . . . . . . . . . . ... D Findeis (Dirk)National Treasurer ................................. K Nyangoni (Kudzai)

Branch ChairpersonsCentral ..................................... . . . . . . . . . . . . . . . . . M Cramer (Mike)Eastern Cape ................................................ W Rall (William)KwaZulu/Natal ........................................... AG Fileczki (Alex)Western Cape ........ . . . . . . . . . . . . . . . . . Prof B Collier-Reed (Brandon)

Portfolios:Communications .............................................. CD Reay (Chris)Education - Universities................... Prof JL van Niekerk (Wikus)Education: Universities of Technology............... E Zawilska (Ewa)Membership .................................................... E Zawilska (Ewa)Seminars and Workshops.................................. D Findeis (Dirk)Technology Programme ................................. SZ Hrabar (Steve)

Chief Executive Officer: Vaughan Rimbault

National Office Manager: Anisa Nanabhay

PO Box �11, Bruma, 2026

Tel: (011) 61�-�660, Fax: (011) �88-��6

Email: [email protected]

Website: www.saimeche.org.za

Membership: Central, Eastern Cape & KZN:

[email protected]

Membership: Western Cape: [email protected]

Company Affiliates

Alstom Power Service SA

Babcock Africa Limited

Bateman Engineered Technologies

Bosch Projects

Fluor SA

GEA Air-cooled Systems

Hansen Transmissions SA

Hatch Africa

Howden Power

Howden Projects

Industrial Water Cooling

MBE Minerals (SA) (Pty) Ltd (previously KHD Humboldt Wedag SA

Megchem Eng & Drafting Services

THE SA INSTITUTION OF MECHANICAL ENGINEERING

SAIMechE Training Events Calendar: Sep to Nov 2010

Whilst every effort is made to ensure that events take place as scheduled, SAIMechE reserves the right to change the schedule as circumstances dictate. A registration form and full terms and conditions may be obtained from Carey Evans on E-mail: [email protected] or Tel. 031-764-7136. Also, detailed individual event programmes are available from Carey. Corporations wishing to book In-House Workshops may contact Linda Robinson on E-mail: linda@saimeche.

org.za or Tel: (031) 764 -7136.

E v e n t Code

Workshop & Seminar Names

Dates Region

H0610 The Engineer As Manager

14-Oct-10 Rivonia

AFP10 Fire Prevention and Control

14-Oct-10 Durban

EPS10 Engineering of Piping Systems

20-Oct-10 East Rand

A1410 Managing a Coal-fired Firetube Boiler

22-Oct-10 Durban

A1210 Psychrometrics & Psychrometric Processes

27-Oct-10 Durban

A0610 The Engineer As Manager

28-Oct-10 Durban

A4610 Value Engineering & Value Management

02-Nov-10 Durban

Osborn Engineered Products SA

Rotek Engineering

RSD a division of DCD-Dorbyl

S.A.M.E Water

Sasol Technologies

SEW Eurodrive

Siemens

SNC-Lavalin SA

Spicer Axle SA

Spirax Sarco SA

Thyssenkrupp Engineering

Transvaal Pressed Nuts & Bolts

Ultra-Flow Engineering Services

Vital Engineering

Weir Minerals Africa

Winder Controls

The Central Branch Dinner DanceDate: Saturday 9th October 2010

Time: 18:30 for 19:00

Venue: Killarney Golf Club

Dress: Black Tie/ Traditional/Smart

Cost: R3 500 per table of 10 or R350 for individual tickets.

R.S.V.P. to Lynne on (011) 615-5660/ [email protected]


THE SA INSTITUTION OF MECHANICAL ENGINEERING


Obituary - Pauline BouwerIt was with great sadness that we heard the news of Pauline Bouwer passing away on 9 September. Pauline suffered a fatal heart attack while leaving her home to come to our offices that Thursday morning.

Having joined Promech on 1 September 1999, Pauline left for a short while in 2003/2004 to freelance on a wildlife magazine before rejoining the company in October 2004. In all 11 years that we knew her, Pauline was a dedicated salesperson who was fiercely loyal to “The SA Mechanical Engineer”. She was openly proud of ‘her’ publication, ‘her’ editor, Kowie Hamman and all those at Promech.

The same dedication, loyalty and support that Pauline applied to her work was reflected in her dealings with her colleagues at Promech and her many clients. But Pauline was not just a col-league, she was also a caring, supportive and valued friend who could keep everyone going with her wicked sense of humour and her wonderful belly laugh. She is deeply missed.

Pauline leaves behind her hus-band, Nick, her daughter Bianca and son-in-law, Nick, her son, Justin, and her youngest daugh-ter, Cassandra as well as her four cats, four dogs and birds. Pauline loved nothing better than to sit in her garden surrounded by her family and her animals, although she’d never say no to a trip to the bush or any wildlife outing.

Our deepest condolences to the Bouwer family, to Pauline’s friends, clients and colleagues. We were all privileged to have known such a special lady.

Efficient, cheerful, dedicated…The theme was “A” and Pauline came as an Angel with some hippy tendencies

Pauline in a 5-year old get-up at our annual Casual Day function

Pictured here with Anisa of SAIMechE at Electra Mining 2008


Vessels up to 130 metres long makes SA Shipyards the biggest ship builder on the African continent

MONTHLY COLUMN

Exceptionally powerful for their size and strongly built, tugboats were the first sea-going vessels to utilise steam propulsion to free them from the restraint of the wind

which allowed the boat to go in any direction. As such, they were employed in harbours to assist ships in docking and departure as well as moving large barges or platforms with no independent means of propulsion.

Over ninety percent of South African imports and exports are channelled through the six main ports,

viz, Richards Bay, Durban, Saldanha, Cape Town, Port Elizabeth and East London and the ships enter-ing these harbours are getting bigger and bigger all the time. As part of the port infrastructure upgrade programmes, several tugboats are being built, right here in South Africa.

New tugboats“SA Mechanical Engineer” visits Southern African Shipyards, a Durban-based company which spe-cialises in tugboats and vessels up to 130 metres long. “The third completed tugboat for the port of Coega is undergoing sea trials as we speak,” says Prasheen Maharaj, chief financial officer of the company. “We got into tug building just after acquiring the company in 2007 after Transet put out a tender for the building of three tugs.

“Soon after getting this tender, we also won a contract to build another two tugs for other ports and soon had five under construction in our facility that can turn out a tug every four months,” Pra-sheen adds. “The design is a very stable tugboat built to world-class standards and powered by the

Tugboats are an integral part of harbour operations. As most large vessels simply cannot manoeuvre through the harbour channels on their own power, they’re reliant on these specialised little workhorses to bring them

alongside the quay for docking.

Vessels for Africa from Africa

The design is a very stable tugboat built to world-class standards


MONTHLY COLUMN

Voith Schneider propulsion system that all top-class tugs use. Currently, the ports want eight more tugs of a similar design and we’re hoping to land some of those contracts as well.”

Special driveThe Voith Schneider propeller (VSP), also known as a cycloidal drive, is a specialised marine propulsion system. It is highly ma-noeuvrable, being able to change the direc-tion of its thrust almost instantaneously. It is widely used on tugs as well as ferries where extreme manoeuvrability is needed.

Walking through the workshop, where several tugs in various stages of completion are being worked on, we see the VSP clearly. From a circular plate, rotating around a vertical axis, a circular array of vertical blades, in the shape of hydrofoils, protrudes out of the bottom of the ship. Each blade can rotate itself around a vertical axis. An internal gear changes the angle of attack of the blades in sync with the rotation of the plate, so that each blade can provide thrust in any direction, very similar to the collective pitch control and cyclic in a helicopter.

Unlike another popular marine propulsion systems where a conventional propeller is tilted on a vertical rudder axis to change the direction of thrust, the VSP drive merely requires changing the pattern of orientation of the vertical blades. In a marine situation this provides for a multi-directional drive, thus doing away with the need for a rudder.

Opportunity galoreBeing able to build vessels up to 130 metres long makes SA Shipyards the biggest ship builder on the African continent. “The govern-

The protection of marine resources along our 2 798 km coastline

The Voith Schneider propeller system

A tug boat nearing completion

Prasjeen Maharaj of SA Shipyards


ment, including the Navy, are increasingly issuing tenders for locally-built ships which is a good thing because we can then invest more in training local artisans in this specialised area,” says Prasheen. “Officially we’re certified to manufacture and repair large marine structures including container vessels, bulk carriers, tankers, patrol vessels, ferries, trawl-ers and oil rigs.

“The tugboat contracts have been keeping the

MONTHLY COLUMN

Ship building is a labour intensive industry

business afloat, but there are lots of opportunities in South Africa that we’ve been working on over the last couple of years,” adds Prasheen. “The Navy, for example, is looking at expanding their fleet of patrol vessels for the protection of marine resources along our 2 798 km coastline and they’ve indicated that the ships have to be built in South Africa. These vessels are usually 85 to 90 metres long and we’re the only shipyard in South Africa that can accommodate this length, so we should definitely be in the running to land some of these contracts.

Old-fashioned appy’sThe company is split into two distinct divisions; ship building and ship repairs. “In reality the two are quite different disciplines in terms of the artisan skills applied,” says Prasheen. “Ship building is a highly-disciplined process where very strict inter-national class specifications have to be followed in a methodical sequence whereas ship repairs, also requiring high skill levels, are less methodical and it’s always a rush to get the ship going again as quickly as possible.

“To this end we’ve invested heavily in an artisan training programme where we’ve opted to go the old-fashioned route as they did back in the day with harbours and port’s appy-ships,” Prasheen adds. “It’s not just a learnership programme, but rather about creating good professional artisans who have pride in their work. Right now, for instance, we have 38 artisans training through this programme before they do the official trade tests to qualify.

Government support“Ship building is a very labour intensive industry and I think the government has now come to realise that industrialisation is key to creating jobs in South Africa,” Prasheen says in conclusion. “That’s why we’ve seen the formation of industrial clusters such as the Marine Vessel Maintenance and Repair cluster to officially assist in the development of specific industrial sectors such as the marine industry.

“We’ve been driving hard to get ship building on the national agenda so that everyone knows we absolutely have the capabilities in South Africa. The potential for this industry to develop into a major source of income is endless, not just in ship building, but also in repairs. It makes no sense for ships to sail right past our ports to have repairs undertaken elsewhere at a much higher cost when they could do it right here.”

Prasheen Maharaj, Southern African Shipyards, Tel: (031) 274-1800, Email: [email protected]

The potential for this industry to develop into a major source of income isendless, not just in ship building, but also in repairs

THE SOUTH AFRICAN MECHANICAL ENGINEER VOL 62 September 2010 1�

While replacing an old compressor with a new energy-saving model does bring about a saving, it’s no use installing it on an old network of leaking pipes with

pressure drops or mismatched ancillary equipment. Any savings whatsoever go straight out the window and people end up blaming the compressor for not performing to specification.

More than meets the eyeThere is much more to an effective compressed air system than just the compressor, and to elaborate on this crucial aspect of compressed air production “SA Mechanical Engineer” speaks to Wayne Jacobs, business manager of the oil-free air division at Atlas Copco in Johannesburg.

“We regularly come across enquiries where people want to buy a new and bigger compressor that will, in spite of the cost of electricity, compensate for an ineffective system down the line,” he says. “They simply regard it as too much trouble to fix the leaks in the pipe work or have the system tested for pressure drops.

“Just one bar of pressure drop due to mismatched piping or ancillary equipment such as dryers or fil-ters results in a 7 percent energy loss,” adds Philip Herselman, business manager of the industrial air division at Atlas Copco. “Due to a lack of mainte-nance, these flaws do creep into a system over time and companies want to compensate for them with

bigger compressors at the source to get a specific working pressure at the delivery point.”

Maintenance“You have to look at the compressed air plant holistically and over the long term,” says Wayne. “You’ll get a much higher percentage saving over a shorter period of time with less capital outlay by addressing things such as leakages and pressure drops from the outset. In addition, it is crucial to maintain the system regularly and at correct intervals. Of all the factors that influence energy consump-tion in a compressor plant, proper maintenance of the machines and the system as a whole can bring about one of the biggest savings.”

The right dryerAnother area where companies often make mistakes in terms of selecting matching equipment in the air system is air dryers. “Although about 95 percent of compressed air installations in South Africa do need air dryers, many people simply don’t under-stand the function of an air dryer, and when, the wrong one is fitted, more unwanted pressure drops are experienced in the system,” says Wayne. “The benefits of taking the moisture out of a system far outweigh the cost of a dryer, but we find that people don’t understand the quality of the air dry-ness they need and more often than not, end up over-specifying.

“It often happens that companies buy a more ex-pensive dryer than necessary, or buy the wrong type of dryer for a specific application,” adds Wayne. “A dryer’s running costs also need to be considered.

Save Air, Save EnergyNew technology on its own does

not save you energy, especially

when it comes to industrial in-

stallations such as compressed

air installations. Many people

think a new compressor with

energy-saving features will re-

duce energy consumption, how-

ever they do nothing about the

other equipment, all integral to

the compressed air system.

COVER STORY

Just one bar of pressure drop results in a 7 percentenergy loss

Philip Herselman, business manager of the industrial air division at Atlas Copco (left) and Wayne Jacobs, business manager of the oil-free air division at Atlas Copco

1� THE SOUTH AFRICAN MECHANICAL ENGINEER VOL 62 September 2010

COVER STORY

Often, a refrigerant dryer can very well be all that is needed, but instead a desiccant dryer is installed which has a much higher running cost.”

Other productsAtlas Copco has a full range of branded in-line equipment, from filters to piping systems and condensate separators to dryers. “Even different brands of in-line equipment in an air system can make a difference and have to be considered to get the optimum performance out of a system,” says Wayne. “For example, in terms of dryers, we have anything from fairly basic dryers right through to premium models, all for specific applications and each having its own characteristics that influence optimum system design.”

Oil-free airYet another big problem lies with the choice of compressor. “Just because an oil-free compressor costs more than an oil-flooded compressor, many people opt for the oil-flooded version and rely on banks of filters to take the oil out of the air,” ex-plains Wayne. “However, from the word go, a filter’s capability drops as it starts collecting oil and dirt from the air stream. This results in increased energy consumption. Cartridges also need to be replaced regularly, significantly increasing running costs due to maintenance.

“Such a system would also need separators and special draining systems for the condensate to comply with the legal requirements, all adding to the running costs of the cheaper machine. In the meantime, for guaranteed constant oil-free air, an oil-free compressor from the start would have been much more cost effective over the same period of time, but people still tend to shy away because of the initial price of these machines.”

Audit serviceLike the ranges of ancillary in-line equipment, Atlas Copco also offers a compressed air network audit service to assist customers and design engineers in choosing the right equipment combinations for an application. “We don’t get involved in process design, but we can certainly advise on the most energy efficient combinations of equipment of an air network layout,” Wayne says in conclusion.

“Our AIRScan system is a highly accurate, inde-pendent survey and reporting system designed to pinpoint the areas where potential savings can be made in a plant. In this way we discover where the energy drain originates from and can take appropriate actions to remedy or optimise the situation.”

Wayne Jacobs, Atlas Copco, Tel: (011) 821-9120, Email: [email protected]

You’ll save more by addressing issues such as leakages and pressure drops


SA Mechanical Engineer” speaks to Grant Stewart, the product manager of Vulco products at Weir Minerals about an alterna-tive which is steadily making inroads in the

South African milling industry. “The Weir SFL lining system (composite lining) is a rubber/chrome molly combination liner for mills which is new to the South African market but has made great inroads in Chile and Australia,” he explains. “Locally it’s new in the sense that we like to partner with the mine in terms of proving the product’s effectiveness, not only against steel but also as far as other liner

materials are concerned.

Rubber liner“To start off building such a partnership we’ve been targeting secondary milling such as ball mills to prove the product’s durability and flexibility,” Grant adds. “Once the mine has seen the results and has confidence in the product, we move onto primary milling as in SAG mills. The old days of just selling a product have long gone, we’re now selling a service where we also assist customers throughout the lifecycle of the liner.

“For instance, we’ll go to site during a shutdown, roll up our sleeves and actually get into the mill in order to do a profile of the liner to determine

Most South African rock is pur-ported to be harder than any-where else in the world, which presents a particular challenge

to ore grinding processes in both autogeneous (AG) and

semi-autogeneous (SAG) mill-ing in terms of the type of liner used. Traditionally, steel linings

have been the norm, but it’s now recognised that some ore bodies have hardness close to, or more, than the metal linings.

Lining up for

Success

CRUSHERS & SCREENS

Grant Stewart the product manager of Vulco products at Weir Minerals

The old days of just selling a product have long gone, we’re now selling a service


the wear life of the product in that given situa-tion. From this we draw up an extensive report so that the client can clearly see the wear ratio inside the mill and plan accordingly for re-lining the mill.”

All mills linedNo two mill applications are identical because even on the same mine, ore can come out of the ground differently at different times and therefore mill linings are usually custom-designed for each individual mill. “The Vulco system offers a broad range of custom-designed rubber and metal cap lining systems for ball, rod, SAG and AG mills, as well as scrubbers,” Grant adds.

“We also have a wide selection of general wear-resistant products including ceramic rubber wear plates, trunnion liners and custom-made wear plates for impact and abrasion protection.”

Strong design capabilitySupported by resources from across the world where the Vulco technology has been tried and tested, Weir’s local team of engineers are strongly design

The harder the material fed into the mill, the more cost effective a rubber lining becomes

orientated. “We sell design to start off with,” says Grant. “Together with the mine’s engineer and our rubber technologist, the designer uses various software tools such as mill trajectory analysis, MLeds, Moly crop and the Unigraphics 3D system to structure a design until he gets the best solution for a particular situation.

“Our in-house facilities enable total control of the entire process, from design through to manufacture and installation,” adds Grant. “To do this, we carry out a complete analysis for each individual milling application. Factors such as mill dimensions, speed, mill power, ore type, feed top size, feed distribution, throughput, charge volume and make-up, density and product size are considered. This allows for the most appropriate design and material selection for the lining in order to achieve optimum performance from the mill at the lowest possible cost.”

The rubberA general rule in terms of mill lining is that the harder the material fed into the mill, the more cost effective a rubber lining becomes. “We’re fortunate in that the rubber compound for the liner products is mixed in-house according to our technologists’ specifications,” Grant elaborates. “Elasticity, high tensile strength and abrasion resistance are some of the inherent characteristics of our compound,

CRUSHERS & SCREENS


making rubber the preferred mill lining over steel. Rubber’s elasticity per-mits restoration of its original profile after im-pact, while the tensile strength prevents it from tearing.

Faster and safer“Rubber also al-lows for a lower installed cost, and since rub-ber and metal cap mill liners weigh up to 80% less than steel a lone, they are faster, easier and safer to install,” adds Grant. “In addi-tion, by reduc-ing the mass of the lining system, a greater charge weight can be utilised which allows for increased throughput.

“Our low profile T-track system forged T-bolt arrange-ment eliminates the need for frequent inspections, repair, and bolt tightening,” says Grant. “At the same time, rubber conforms to the mill’s internal surface which creates a seal that prevents leakage and slurry erosion of the mill shell. All these factors contribute to longer wear life with fewer maintenance interruptions and greater mill availability.”

ServiceHowever, it’s not just its meticulous design features and special rubber characteristics that have made Weir’s Vulco linings a success in South Africa. “We’re in it for the long haul,” says Grant in conclusion. “Our service approach to the business includes constantly inspecting installations so that we can plot trends for each installation and thereby remain on top of problems as they may arise. Not one installation is the same, and being in constant touch lets us tweak slight problems so that the customer gets the best service and value out of his rubber lining system all the time.”

Grant Stewart, Weir Minerals Africa, Tel: (011) 929-2799, Email: [email protected]

CRUSHERS & SCREENS

We carry out a complete analysis for each individual milling application

Vulco rubber mill lining systems are ideal for ball mills


The launch of the SAPCI-KZN chapter is be-ing initiated by the Durban branch of Mid-rand based Planning and Cost Engineering Services (PaCE) and Bingelela Consulting

Professionals, who have teamed up to improve the working relationship between cost engineers and quantity surveyors - two groups who are known to have their differences in the engineering world.

Full backingThe initiative has received the full backing of the Johannesburg chapter of SAPCI and is being under-taken in conjunction with the Association of South African Quantity Surveyors (ASAQS). The new launch aims to bring the two professions closer through mutual partnerships, while improving opportunities and skills for all its members.

The driving force behind the project will also involve high-level discussions with universities about offering degree courses in Cost Engineering, a qualification which is currently not available and the certifica-tion only being obtainable in South Africa through the USA-based Association for the Advancement of Cost Engineering (AACE) after eight years of working experience.

Uniting Disparate ProfessionsBridges are being built in the engineering world as KwaZulu-

Natal opens the first chapter of SAPCI (Southern African Proj-ect Controls Institute), a move which is seen as the perfect platform for the city preparing to host the 2012 ICEC World

Conference.

Nic Bennett MD and CEO

It’s about time that we stop being cousins and finally become brothers

Another primary aim will be to help quantity sur-veyors who struggle to get into cost engineering because of its specialist nature.

Catch 22Managing director and CEO of PaCE, Nic Bennett says, “The catch 22 situation which has both sides in a difficult position is the fact that cost engineers are not able to obtain a BSc qualification for their profession, but instead become proficient through training and their experience in-field. Quantity surveyors on the other hand, are able to obtain a tertiary qualification, but struggle to branch out into cost engineering because it is too specialised. It’s about time that we stop being cousins and finally become brothers. We work so closely together in similar fields, yet there seems to be this rift between our professions that ultimately results in doors be-ing closed and opportunities limited.”

Corporations are being encouraged to invest in the project by becoming corporate members, and allow their employees a few hours off each month to attend useful workshops and seminars, designed to vastly improve the skills and qualifications of those who attend.

SAPCI, Tel: (011) 478-1540, Fax: (011) 478-1540, Email: [email protected], www.sapci.org.za

COST ENGINEERING


In tests conducted at Mintek in Johannesburg, this 20 percent saving has been realised time and again in

a high pressure grinding roll (HPGR) crusher pilot plant that has been running for over a year. Old technology never dies, but it may sit on the shelf for a couple of years, until new materials and processes that appear on the market help to eliminate the weak points in the original design. This is what happened to the use of roll crushers for hard rock processing.

HPGRHigh Pressure Grinding Roll (HPGR) technology, first intro-

duced in 1985, was originally used in the cement industry to treat non-abrasive materials. The benefits enjoyed by the cement industry through the use of this technology did not go unnoticed by other industries, which resulted in some sectors trying out

the new technology in their comminution circuits.

However, because ores in the mineral industry are between 20 and 50 times more abrasive than cement raw materials, higher than acceptable wear rates were experienced, as the surface of the roller deteriorated rapidly with the process-ing of the more abrasive materials found in gold and platinum mining.

Later on, as harder steel surfacing technology be-came available, this prob-lem could be addressed, which led to HPGR tech-nology being ‘revived’ as a more economic alternative to popular size-reduc-tion processes, such a ball mills, in hard rock mining.

“SA Mechanical Engineer” meets with Dr. Johnny Kalala, the head of comminution at Mintek’s mineral processing division, to talk about this project. “All indications from our tests and two actual installa-tions in the platinum processing industry show that HPGR technology integrated in comminution circuits has the potential to save around 20% in energy consumption per tonne, compared with using only conventional grinding equipment,” he says.

“Our research is focused around this technology, not only for the energy saving aspects but, at the same time, looking at better liberation through the inter-particle crushing that takes place with a HPGR system.”

The facilityMintek has a comminution piloting facility that in-cludes a SAG mill, crushers, a Köppern HPGR unit with a diameter of one metre, a Polysius HPGR unit with a diameter of 0.250m, primary and second-ary ball milling facilities, a stirred media detractor (SMD), a Deswick mill, a Derrick screen and hydro-cyclones. As we walk through the facility, Johnny explains that the comminution pilot plant not only

A RevivalJust mention a saving in energy consumption and any mining engineer will sit up and take notice, especially if it concerns the comminution process, where crushing and milling machines are the big energy guzzlers. A

20% energy saving in this department adds up to a huge cut in any mine’s energy bill, not to mention reduced costs in capital outlay, savings on consumables such as steel balls and downtime in maintenance stoppages to

replace them.

CRUSHERS & SCREENS

Dr Johnny Kalala of Mintek

Counter-rotating rolls mounted on heavy-duty bearings and enclosed in a frame


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TMMATROX is virtually unbreakable and offer the lowest surface friction

of any liner material. Lightweight (1/8 the weight of steel), it is easy

to handle and install and offer excellent corrosion, wear and abrasion

resistance.

TMMATROX will not be affected by extreme weather conditions and

resists moisture and UV degradation(up to 110 °C).

Don’t compromise productivity.

Contact Maizey Plastics for a consultation on improving bulk materials handling and reducing operational costs.

It’s extreme

resistance to abrasion is up to 2 times better than non alloy structural

steels, and 6 times better than aluminium when subjected to relative

volumetric wear in a sand slurry process.

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serves to collect data for research, but is used for pre-feasibility and feasibil-ity studies for different clients since data generated can be scaled up for industrial use with fewer risks.

How it worksThe HPGR consists of two counter-rotating rolls mounted on heavy-duty bearings and enclosed in a frame. Pressure is applied to one of the rolls, called the floating roll, by means of a hydro-pneumatic spring system, while the other roll is held in a fixed posi-tion in the frame. The floating roll is allowed to slide on pads in response to the forces acting on the roll by both the feed material and the hydro-pneumatic spring system. Feed to the rolls is provided by means of a hopper mounted above the rolls, which is equipped with a level controller to ensure that the rolls are continuously choke-fed.

The rolls are driven by separate motors connected to the roll shafts through gear reducers, which can be operated at a fixed speed or variable speed, de-pending on the demands of the process. The actual rollers are solid, with their surface protected against wear by special wear-resistant materials such as the tungsten carbide studs on the surface of the roller on their Polysius machine, which Johnny points out to us.

“We’re also looking at the feasibility of different configurations in the comminution chain, where the HPGR can be used in conjunction with a ball mill, for example, so that the throughput of

A smaller version of the roll mill at work at Mintek

the ball mill can be increased significantly,” says Johnny. “We’re gathering and processing the data from a HPGR followed by the Deswick mill circuit configuration which has the potential to not only reduce the specific energy consumption but also has the advantage of not using steel grinding media which increases the operating cost of conventional tumbling mills.”

South African firstOne of the first installations of large scale HPGR in the platinum industry in South Africa, built by joint venture company Vhumbanani Projects, has been commissioned at Anglo Platinum’s Potgietersrust Platinum (PPRust) North Mogalakwena section. This is the first time in the platinum industry that HPGRs are being used on platinum group metals (PGM) ore, where a large 1-MW drive powers the primary crusher, which is the largest of only two installed in the country. The HPGR is used to bypass the primary mill and feed ore directly into the mill discharge sump without milling it, process technology that was designed by Angloplat.

Dr Johnny Kalala, Mintek, Tel: (011) 709-4516, Email: [email protected]

CRUSHERS & SCREENS

The throughput of the ball mill can be increasedsignificantly

National Number - 086 1100 420

www.maizey.co.za | [email protected] DISTRIBUTOR OF QUALITY BRANDS

TMMATROX is virtually unbreakable and offer the lowest surface friction

of any liner material. Lightweight (1/8 the weight of steel), it is easy

to handle and install and offer excellent corrosion, wear and abrasion

resistance.

TMMATROX will not be affected by extreme weather conditions and

resists moisture and UV degradation(up to 110 °C).

Don’t compromise productivity.

Contact Maizey Plastics for a consultation on improving bulk materials handling and reducing operational costs.

It’s extreme

resistance to abrasion is up to 2 times better than non alloy structural

steels, and 6 times better than aluminium when subjected to relative

volumetric wear in a sand slurry process.

TM

60years

MATROX™ solves friction, wear and flow problems across various industries.

From truck bed linings, rail car linings,silos, hoppers and chutes in the transportation,storage, mining & bulk materialsprocessing industries.

HIGH PERFORMANCE POLYMER OPTIONS

You can DEPEND on US...


SAIT

The SAIT has been running the Lubrication Engineering course for many years, giving candidates a local qualification that is well respected. A certificate is only received

after passing an examination, at the end of a busy

Get Tribology CertifiedMost professions have a benchmark qualification that signifies a level of competency that makes customers

happy to deal with them. For lubrication engineers, salespeople and technical managers involved in tribology, there are very few such qualifications, and little recognition in South Africa.

5-day course.

Need for international recognitionHowever, there is a demand for an in-ternationally recognised qualification, especially amongst the many South African companies that are trading globally, as well as global companies with bases in South Africa.

With the rising cost of capital equipment and the maintenance thereof, it is essential that the person in charge of lubrication is competent.

CLS ExamThis is an internationally recognised qualification and has been run for the past 8 years by the SAIT through its association with the STLE (Society of Tribologists and Lubrication Engineers, based in the US).

The exam is run in South Africa annu-ally, and this year it will be on the 19th November, at the SAIT offices in Kelvin, Johannesburg. As this exam is US-based, all measurements are Imperial (although metric equivalents are given).

The question paper is unique for each candidate as the questions are randomly drawn from a large database, so fairness is assured.

Over the years, the SAIT have created a similar database of old questions, and these are invaluable in preparing for the exam.

Preparation CourseDue to the difficulty of preparing for this exam, the SAIT runs a preparation course for CLS candidates. It will be run for the 2 days before the exam and will be facilitated by a current CLS holder.

The agenda will include: Imperial measure-ments, the Lubrication Engineers Manual, previous questions, exam techniques and

various technical subjects.

Additionally, all candidates who are signed up for the course will receive preparation modules for a number of weeks before attending.

SAIT, Gill or Isabel, Tel: (011) 802-5145), David Beard, Tel: (082 850 3205), www.stle.org, www.sait.org.za


POWER GENERATION

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DisclaimerPROMECH Publishing does not take responsibility for the opinions expressed by individuals.

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CopyrightAll rights reserved. No edi-torial matter published in “Power Generation 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, au-thors, 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 conse-quences 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.

The winds of change are steadily blowing across the South African continent, transforming the potential of alternative energy generation as more and more projects become a reality every year. There’s a lot of talk about all the differ-ent means of generating energy, from biomass to hydro systems, alternative

fuels and various forms of harnessing the sun’s abundant energy, but the one that is rapidly gaining the lead is harnessing the winds, especially along our

coastal regions.

SA Mechanical Engineer” takes a look at wind turbine projects in South Africa with a second wind farm taking shape near Port Elizabeth.

The first project is near the little village of Darling on the Cape West Coast where enough strong and consistent winds justi-fied building South Africa’s first wind farm, on the gentle sloping hills of Klipheuwel near the town. In fact the winds are gentle enough not to upset Tannie Evita’s (Pieter Dirk Uys) hairdo as she strolls down the platform of Darling’s train station to open up ‘Evita se Perron’, one of the West Coast’s most popular restaurants.

Darling Darling’s ‘winds’ are now sold as electricity into the utility grid, bringing not only some relief to the energy crisis, but also brand new technology to the African continent. This is the first grid-connected, independent wind energy power-generating facility developed in South Africa. The Darling Wind farm

Company (DWP) signed a 20 year Power Purchase Agreement (PPA) with the City of Cape Town as well as a Power Wheeling Agreement with Eskom.

Of the turbines at Klipheuwel, the most basic unit is performing the best under high wind conditions in summer, while the largest turbine is performing the best under weak wind or winter conditions. Overall, total production annually has been just more than 4GWh. The Klipheuwel wind farm has a total capacity of 5.2 MW from the four turbines, mounted on 17-storey high tow-ers. The units are each powered by three 33.5 metre blades, being longer than the wing of a Boeing 747-400. Each 42-ton engine room at the top of the tower has a 1.3 MW capacity delivering an expected annual yield of 13.2 Gwh clean energy from phase one of the Darling project.

Speeds neededThe wind turbines at Klipheuwel generate at wind speeds between 11 and 50 km/

Powered by Nature

The windfarm near Darling

2� THE SOUTH AFRICAN MECHANICAL ENGINEER VOL 62 September 2010

Gentle enough not to upset Tannie Evita’s (Pieter Dirk Uys) hairdo

POWER GENERATION

hour. Full power is reached at 50 km/hour. Generally a wind speed of around 16 km/h is needed to start generating electricity while the optimum for large turbines is approximately 48 kilometres per hour. Wind speed usually increases with height especially where there are no natural or man-made obstructions.

This is why you’ll usually find wind farms on hilltops or in the middle of large open fields. But an increasing numbers of wind farms are today being erected offshore.

The latest projectThe second wind farm seeing the light in South Africa is just outside Port Elizabeth. The Belgian green electricity company Electrawinds started construction of a wind turbine in the harbour of Coega, near Port Elizabeth earlier this year. This marks the first commercial wind project in South

Africa as well as the start of the first phase of a large wind farm that, in time, will comprise 25 wind turbines. For Electrawinds, this will be the first operational project outside Europe.

The installation of the first of the 25 turbines was a rush-job as the aim was to be ready for World Cup South Africa so that the energy produced by the turbine between 11 June and 11 July 2010 could be given to the Nelson Mandela Bay Stadium in Port

The Coega wind farm


POWER GENERATION

Elizabeth, which is on the same electricity grid.

Record time“If there were a wind turbine construction world championship, Belgium would undoubtedly take top honours,” says Marleen Vanhecke, PR and communication manager of Electrawinds. “From signing the contract with the Danish turbine con-structor, Vestas, to the production of the first green energy, the entire project took barely three months. Such a project could normally take up to eighteen months. However, this job had to be done quickly as the authorities in Port Elizabeth insisted strongly that the turbine had to be ready for the start of the World Cup.”

The wind turbine (Vestas V90 – 1.8MW) has been built in the new port area of Port Elizabeth (Coega), which is only a stone’s throw from the World Cup stadium. By 2012, Electrawinds aims to construct a large wind farm of 25 turbines, a total investment of at least 100 million Euros.

Pioneering South Africa “In Belgium, Electrawinds is one of the pioneers of renewable energy and has, in the meantime, built

If there were a wind turbine construction world champi-onship, Belgium would undoubtedly take top honours

Port Elizabeth iin the far background of the wind farm near Coega

The Klipheuwel wind farm has a total capacity of 5.2 MW

up great know-how,” says Luc Desender, managing director of Electrawinds. “It is now our ambition to fulfil that pioneer-ing role in South Africa as well. There is great support here for renewable energy which offers good prospects.”

Says Khwezi Tiya, executive manager, Coega Development Corporation (CDC), “Electrawinds will also start a student training programme in South Africa. They will be managing the educational programme and have cooperated with CDC for the selection of the first three candidates. The students started an engineering programme in January 2010

at the Nelson Mandela Metropolitan University. For further specialisation, there is a postgraduate programme offered in Europe.”

More than power“We want to invest not only in turbines but also in people,” says Jan Dewulf, director business development at Electrawinds. “With Emil Unger, Electrawinds already has a representative in South Africa but through the required training, we also want to offer local young people opportunities so that, in time, they will be able to follow up our projects in South Africa.

“Right now, South Africa doesn’t have enough quali-fied staff in the sector of renewable energy and the scholarships being provided by Electrawinds will make an immense difference to the recipients.”

Electrawinds NV, John Cordierlaan 9, 8400 OostendeBelgië, Tel: 00 32 (0)59 56 97 00, Fax. 00 32 (0)59 56 97 01, Email: [email protected]


POWER GENERATION NEWS

Operations expandedThe Cosira Group, one of the largest structural steel fab-ricators and erectors in Southern Africa, has announced its involvement with some construction contracts that are currently being executed in Southern Africa, particularly in the mining and power generation sector.

John da Silva, CEO of the Cosira Group, says that there is currently significant growth within the power genera-tion sector, which is a strategically important sector of development in Southern Africa at the moment.

In the later part of last year, Cosira was awarded the structural steel contracts for Al-stom – initially Medupi Turbine Hall and then in a Joint Venture with Co-sira Tubular the Kusile Turbine Hall.

Work is also progressing well on the complete structural, mechanical, platework and piping (SMPP) supply and erect order for the up-grade of Xstrata Coal’s ATCOM Coal Handling and Preparation Plant (CHPP) in Witbank which was recently awarded to the Cosira Group by Sedgman.

Furthermore Cosira was recently awarded the supply contract for the Riversdale Benga Coal Processing and Washing Plant (CPWP) project, located in Mo-zambique. Riversdale awarded the structural

and platework contract to Cosira through Sedgman. This contract entails the supply and fabrication of approximately 1 680 tonnes of structural steel and platework and is scheduled for completion in November of this year.

In addition, the Cosira Group has been awarded the struc-tural, mechanical, platework, and piping (SMPP) supply and installations for the back-end of a new uranium plant at Trekoppje Mine by Areva.

Cosira has also been awarded the additional Unki Feed Conveyor structural, mechanical and piping (SMP) project in Zimbabwe. This award follows the successful comple-tion of the structural, mechanical, pipework and platework installations at the Unki Platinum Mine and Process Plant, 80km from Gweru, on the Zimbabwean Dyke.

Cosira Group, (011) 817 6600, Email: [email protected], www.cosiragroup.com

Flue contract on scheduleDSE’s recently awarded contract by Karrena-Concor Joint Venture to fabricate and install flues at the Mepudi Power Station has seen the delivery of the first flue.

The entire contract comprises of some 1 800 tonnes of structural steel and 3 000 tonnes of plate work. There are two 213 metre high chimneys, each with three flues and the entire project has to be completed over the next two years.

DSE was engaged with MM&G to undertake the site fabrica-tion of the cans and the structural steelwork.

A bird’s eye view of the chimney platform being assembled.

The scale of the entire Medupi Power Station project resulted in DSE building new facilities in Vanderbijlpark with the req-uisite capability to handle the sheer size of the trial assembly. On schedule, and in co-operation with MM&G, DSE started the fabrication of cans in May, and fabricated test products to monitor welding characteristics and understand the actual processes required to successfully execute the work.

The flues are designed and fabricated in both mild and stain-less steel cans, all prepared in the same facility.

Kobus Marais, DSE (a division of Grinaker-LTA Mechanical & Elec-trical), Tel: (011) 871 4111, Fax: (011) 871 4141


POWER GENERATION NEWS

Call for revenue-neutral carbon taxAnja Finnern, Chairperson of the Carbon Tax Committee at the South African Institute of Chartered Accountants (SAICA) and manager of Tax Services at KPMG, believes that as carbon tax is here, it must be revenue neutral.

In other words, the efficacy of carbon tax should not be measured by its revenue yield but by its impact on emissions in the context of overall government mitigation policy.

She urges companies to formulate a common position on carbon tax, pointing out that South Africa is behind the international curve.

“Companies must recognise the importance of helping to develop fiscal measures applicable to climate change. Allied to this is the need to demand that the various state depart-ments converge on one mitigation policy. Failure to do so creates uncertainty and does not help business.”

Anja firmly believes that the best carbon tax would yield no net revenue, but would change behaviour towards the overall policy of shifting to less emission-intensive sectors.

“If carbon tax does raise new revenues, the proceeds should be directed to capacity building for less carbon-intensive energy solutions.”

Muneer Hassan, SAICA’s project director of tax, highlights the November 2009 climate change workshop convened by the National Business Initiative (NBI) and Business Unity South Africa (BUSA).

“The workshop concluded that South Africa’s relatively high greenhouse gas intensity and position in the global economy in comparison to less developed countries meant that significant global pressure would be felt to respond to climate change.”

He emphasises the workshop’s findings that the reporting of greenhouse gas emissions using existing international ap-proaches had to be prioritised by all businesses, especially since South Africa’s relatively high greenhouse gas intensity may place companies in the country at a long-term competi-tive disadvantage.

“The fundamental link between energy and greenhouse gas emissions emphasises the importance of energy efficiency,” says Muneer, who supports the workshop’s call for busi-

nesses to collaborate with government and Eskom, using one collective voice to influence

the make-up of the energy grid and promote the use

of less carbon-intensive

energy sources.

SAICA, Thando Pato, Tel: (011) 621-6898, Email: [email protected]


NUCLEAR INSTITUTE (SA BRANCH)

You may be familiar with Eskom’s power sta-tions diagram which we’ve taken the liberty of reproducing below. It shows, or would show if the lettering were larger, that this

country is powered by the equivalent of ten large (4 000 MW) power stations. In 1955 the country was run on little more than half the number of power stations. Load growth then set in and played havoc with planning. Eskom assumed that a growth of 9 percent per annum would go on for ever and over-built, but then Government intervened and nothing was built at all. Only the recession has saved us from further load-shedding. We also see from the diagram that all today’s power stations will have been decommissioned by about 2050.

Scary stuffI find this diagram scary. The 4% growth line shown will now kink as it did in the 1990s. But if the targeted 6 percent growth in GDP and the associated 4 percent load growth resume after 2010, by 2050 we will have had to build forty new large power stations. The area to the right of and far above the Eskom graph will have to be filled completely with new power stations. Even at a 2 percent load growth from 2010, we will need over twenty new large stations by 2050. That starts to sound a little more manageable but still means a brand new six-pack every two years or a Koeberg every year for ever. This at a time when all other

countries are competing for capital and hardware to do the same.

More reserves and new technologies will always be found, even if we do have to pay a bit more. Man is an ingenious animal and there is no point in trying to anticipate future technology, just go with the flow. And what about nuclear fusion? It’s a state of mind that I don’t buy.

What reserves do we have? Available estimates vary, but in very round numbers we seem to have about fifty-billion tonnes of readily recoverable coal. Subject to coal quality, a 4 000 MW station burns some 0,7-billion tonnes during a fifty-year life. Therefore, if we elect to use half the available coal for power generation, we have enough for about forty more large coal burners. With a 4 percent load growth we would find ourselves building our last conventional coal-fired station around the middle of the century, environmental considerations aside. And after that there’s any amount of less readily accessible coal.

Light at the end of the tunnelCorresponding sums for uranium reserves yield bad news and good news. Divide known South African reserves of perhaps 0,7-million tonnes by ten thousand tonnes for a 1 000 MW reactor life-time and you get about eighteen of our postulated 4 000 MW power stations. Not overly impressive. The good news is that nuclear technology is still at the adolescent stage and with new fuel cycles now being developed, with breeder reactors and with thorium and the possibility of uranium extraction from seawater, the reserve becomes effectively infinite.

But now recall that South Africa has far more than its fair share of energy resources. With less than 1 percent of the world’s population, we have around 6 or 7 percent of world’s known readily recoverable resources of both coal and uranium. Other countries are going to hit the energy buffers before we do. Solar will help, at a price, but erratic wind energy does not impress. Hydro is reaching the limit.

All of which brings me back to Dr. ElBaradei. He points out that the International Energy Agency is an OECD rather than global organisation, and that global organisations do exist to coordinate efforts in world health, food production and all manners of financial and trade matters. He points out that, the plethora of such organisations notwithstanding, preparing for the gathering energy crisis* is urgently necessary. I, for one, don’t feel like arguing.

John Walmsley(* ‘Tackling the global energy crisis’, Mohamed ElBaradei, IAEA Bulletin, September 2008)

World EnergyMohamed ElBaradei, outgoing Director General of the Interna-tional Atomic Energy Agency, visited South Africa in late July. He appeared to have spoken mainly with Foreign Affairs about

weapons proliferation. This month’s offering is prompted by another theme of his, coping with what he sees as the oncom-

ing world energy crisis.

By 2050 we will have had to build forty new largepower stations


I t will be the first time that the WCNDT will be held on the African continent and SAINT is organising the conference for the international NDT fraternity to communicate the latest de-

velopments in NDT and for Africa to take note of what can be done in the field of NDT. African countries will be actively encouraged to partake in the event.

Please diarise the dates and put plans into action to be a part of this conference. The conference is the place where new doors can be opened, new friendships can be moulded and new ventures can be formed.

Wheels in motionAll the wheels have now been put into motion to promote and market the event. The first call for papers will be issued by the end of September 2010 and the marketing committee is in the process of approaching equipment and service providers to become involved in the exhibition, which is intended to be a window into what is available on the world market. From interactions with exhibi-tors at the 10th European conference on NDT in Moscow earlier this year, it can be stated that the exhibition associated with the conference will be a memorable experience.

SAINT would appreciate it if the South African NDT fraternity could start to prepare papers to be presented at the conference, to showcase the South African NDT industry and activities. The industries who at this stage are not aware of what NDT can offer are encouraged to make time available to at-

tend the conference. Attendance of the conference will be like looking into a window which reveals the world of safety assurance, quality control and condition monitoring as it is performed and avail-able today.

While a number of conferences on NDT are being staged, both locally and internationally, it must be remembered that this conference staged in Durban is the World Conference, ie, the occasion where the NDT fraternity from all the continents gets together to exchange developments which are at the leading edge of the technology.

What to expectIn the forthcoming months, the SAINT column in this publication will focus on the 18th WCNDT in Durban. This is done intentionally so that the engineering fraternity, which includes the mechani-cal-, chemical-, petrochemical-, civil- and trans-port industries, can become aware of the unique opportunity which is offered to the industries in South Africa by the staging of the conference in our country. The show case is opening on our door step. Please make use of the opportunities offered through this venture.Should you wish to participate in the WCNDT, log onto http://www.saint.org.za/ and download the 18th WCNDT invitation. Manfred Johannes, SAINT President andPresident of the 18th WCNDT

NDT in Service of Society

Non-destructive testing in safety assur-ance, quality control and condition moni-

toring is the theme for the 18th World Conference on Non-Destructive Testing (WCNDT) which will be staged at the

International Conference Centre (ICC) in Durban from 16 to 20 April 2012. SAINT was appointed by the International Com-mittee on NDT (ICNDT) in 2004 to orga-

nise this conference in 2012.

SA INSTITUTE FOR NON-DESTRUCTIVE TESTING

The idea is for South Africa to become au fait with what NDT has to offer

�0 THE SOUTH AFRICAN MECHANICAL ENGINEER VOL 62 September 2010

OILS & LUBRICATION

Years ago, Eben du Plessis of Producut faced this exact problem when he was asked to design a lubrication system for the tools used to saw aluminium. He reasoned that

if he could get rid of the soluble oil, he’d be cutting out the process to dry the chips which would not only save time, but also the huge cost of equip-ment and energy associated with the cleaning and drying process.

MQLThis gave local birth to the concept of MQL (minimum quantity lubrication) which his company

has got down to a fine art over the past 15 years and for which Eben won the Louw Alberts award from the SA Institute of Tribology last year. “Micro-dosing is also referred to as ‘near dry’, MQL or ‘mist lubrication,” explains Eben.

“Micro-dosing is the technique whereby minute quantities of lubricant are applied in an industrial operation, leaving an almost dry product and produc-tion environment. MQL requires special micro-pumps that can deliver between 3 and 30 micro-litres per pulse. We control the pumps through changing the pulse rate. Therefore the exact dosing parameters can be established to meet the specific needs of an operation whether it is metalworking, the lubrication of bearings, chains or dies,” he adds.

Case studyDosing is accompanied by carefully-controlled air to disperse lubricant at the exact point of lubrication, to blow away chips in the case of metalworking and to provide cooling of the tool. A case study was performed at an aluminium smelter in 1991 where an aluminium cast ingot or slab was cut with a two-metre diameter circular saw where large volumes of conventional water soluble oil was pumped onto the blade.

“We introduced MQL on a second saw and after

Oiling The WayWhen working with aluminium in smelters, the billets and ingots that are produced have to be cleaned and

cut to size. The large planes and saws used for this task produce a large number of aluminium chips that must be returned to the melting furnace. However, the chips first have to go through a cleaning and drying process because they are usually drenched in a soluble oil that serves to lubricate the tools. This water-based solution

will cause an explosion in the furnace if it’s added when the chips are wet.

Eben du Plessis of Producut

Jacques Theron, technical manager at Producut shows the control box of the system

A German company using our systemreported a saving ratio of 60 000: 1

THE SOUTH AFRICAN MECHANICAL ENGINEER VOL 62 September 2010 �1

a year the results when comparing the two operations, were quite remarkable,” says Jacques Theron, technical manager at Producut.

“On the conventional machine, the us-age of neat cutting oil was 65 100 litres while the MQL saw only used 110 litres with equal tonnages of slab being cut. At a ratio of almost 600:1 this meant that almost 600 times less lubricant was used to do the same job. We have since not only improved the efficiency of dosing equipment, but also the lubricant itself to achieve even higher efficiencies.

“A recent example is typified by a Ger-man company using our system which reported a saving ratio of 60 000: 1, the 60 000 being 10% concentration soluble oil and 1 being neat oil.”

SavingsIn the case of the aluminium smelter, the saving wasn’t only in terms of lubricant and tooling. “The chips from the saws had to be dried by centrifuging and then oven dried before re-melting could take place,” explains Jacques.

“With MQL, the chips now go directly to the melting furnace. Furthermore, the production floor no longer poses a danger to operators who used to slip on the oily floors. The usual problem of skin disorders from the soluble solutions is a thing of the past while the ingress of unwanted moisture into gearboxes, bearings, slides and electronic controls has disappeared, resulting in less main-tenance and downtime on equipment.

Energy“In metalworking, electricity consumption is a good indicator of the efficiency of the operation,” adds Jacques. “The moment the tool goes blunt, the machine starts drawing more amps and the noise level and pitch increases. Using conventional lubrication, where the cutting fluid, neat or water soluble, is constantly circulated, the effectiveness of the lubrication tends to drop.

In a MQL system, every drop of lubricant is fresh and there is no depletion of EP/AW additives, resulting in a significant increase in tool life. In one of our case studies, blade changes dropped from

The special nozzles that spray lubricant onto specific areas on machinery

Control and the pumping system inside the control unit

The blending plant

OILS & LUBRICATION

After a year the results when comparing the two operations, were quite remarkable


69 to 18 times per year and blade repair costs decreased 11-fold. So, MQL boils down to being an energy-light option that adds to your savings.”

In the case of MQL, there is no fluid to dispose of. “To dispose of spent water soluble oil however, is not so easy and the new Waste Act regards it as a controlled substance,” says Jacques. “The fluid has no commercial value and cannot be economically recycled, leaving only slimes dams as a possible disposal option. We have seen clients having to dispose of this fluid in swimming pool volumes more than once a year.”

BlendingEben takes us through to Producut’s lubricant blending plant which is by far the cleanest oil blending facility we’ve ever seen. You can literally eat off the floor, not only because it’s so clean, but also because the oils are mainly natural. “Because MQL means the discharge of lubricant into an open environment, we opted for esters as our main base fluid,” explains Eben.

“Esters, being either natural plant oils or synthetic from renewable sources, have excellent lubricity. They are also safe as they have a high flash point, are soluble, bio-degradable, have no or very low

OILS & LUBRICATION

toxicity values and are non-flammable. As MQL lubricants operate mostly in boundary lubrication conditions, we blend in Extreme Pressure, Anti-Wear and Anti-Oxidant additives. These additives are sourced from reputable international manufacturers and carry US FDA approval ratings for lubes with incidental food contact.

Customised“Apart from the obvious cost savings, industry must start looking at sustainable solutions and stop clinging to ox-wagon technology,” says Eben in conclusion. “Our hardware, lubricants and solutions are adaptable to a large variety of applications and materials. We’re busy looking at systems specifically designed for the cutting and machining of yellow metals and have even designed and built lubrica-tion systems for stainless steel cutting as well. Each system and the lubricant it uses is designed for each individual application.”

Eben du Plessis, Producut, Tel: (012) 804-0844, Email: [email protected]

Having to dispose of this fluid in swimming poolvolumes more than once a year

THE SOUTH AFRICAN MECHANICAL ENGINEER VOL 62 September 2010 ��

I f the lubricator had to inadvertently add the wrong grade of oil to a multi-million rand machine, it not only affects the machine’s performance, but could seriously damage it and even lead to

premature failure. Besides influencing production, machines not running at optimum performance waste energy, adding to the running costs of the plant and directly affecting the company’s bottom line.

What is tribology?In South Africa there is a lot of this going on, ultimately affecting the country’s economy due to sheer ignorance through lack of understanding about the importance of tribology in machinery. By definition, tribology, as a branch of mechani-cal engineering, is the science and engineering of interacting surfaces in relative motion. It includes the study and application of the principles of fric-tion, lubrication and wear.

The projectA project to determine the cost and energy saving potential of tribology to the South African industry was started a year ago by the South African Institute of Tribology (SAIT) and to catch up “SA Mechanical Engineer” speaks to the president, John Fitton, about

some of the impressions they’ve come to so far.

“We’ve been speaking to a broad cross-section of all industries from an energy perspective in relation to power consumption and lubricants,” he says. “We’re not only looking at the costs of breakdowns that oc-curred due to lubrication related failures, but we’re also looking at it from an energy efficiency perspec-tive. For instance, not maintaining idlers properly in a conveyor system is hugely inefficient.

An example“From a machine-life perspective, we’ve found that today white metal bearings in South Africa only last six to eight years, whereas they used to last 20 years in the past,” John adds. “And it’s not because of the lubrication, there’s nothing wrong with the lubrication or the bearing. It all boils down to the lack of skills and knowledge which are impacting on the cost of operations in this country.”

Generally, the industry seems to cut down on the cost of lubrication, filtration and maintenance, despite it usually being a small percentage of a budget. “If you worked the maintenance budget out against turnover, it is generally a very small percentage, yet people tend to opt for cheaper lubricants to try and save money,” he explains. “What they don’t understand is that by increasing the lubrication budget slightly, they’d be dramatically reducing downtime costs caused by lubrication related failures.”

Proper filtrationTo illustrate the importance of proper filtration, John recalls a case of a factory in Durban. “The company was changing between fifteen and twenty white metal bearings a month at a cost of 1.5 million rand a year,” he says. “Since installing a lubrication filtration system, they’re changing no more than five bearings a year. Add to this the increased up-time production, and the cost of the filtration system

OILS & LUBRICATION

Good Tribology Saves Energy

The job of a lubricator on a plant is unavoid-ably a dirty one as it is inevitable that he will spill oil on himself as he goes around

checking the oil levels and filling machines on his daily rounds. For this very reason, the

responsibilities of the lubricator are more than often allocated to the least educated, lowest paid worker on the plant, which is

often the biggest mistake anyone can make.

President of SAIT, John Fitton

We’ve found that today white metal bearings in South Africa only last six to eight years, whereas they used to last 20 years in the past

�� THE SOUTH AFRICAN MECHANICAL ENGINEER VOL 62 September 2010

becomes a mere drop in the ocean.”

The outcome of the SAIT study will be used to benchmark South Africa and highlight areas of concern where greater effort is required such as specific applications, general education, skills im-provements and research and development.

Issues“Initially, we started off with a survey but could not get enough information using this method,” says John. “We then started actively visiting companies to spend time with the maintenance manager, engineers and plant operators to gain access to as much information as possible. This provided insight into the skills-levels, knowledge and the extent of education in terms of tribology that people in the company have gone through.

“The results were particularly scary as the level of knowledge on tribology and lubrication practices is almost zero in most cases. Because of this we intend to highlight all these issues to try and in-troduce tribology into all forms of education, from artisan training to engineering.”

Too much or too littleFrom the study, it is clear that not many people understand what tribology is, let alone apply the

OILS & LUBRICATION

The level of knowledge on tribology and lubricationpractices is almost zero in most cases

basic principles which are not as complex as is generally assumed. “Basically tribology is the study of wear due to friction and lubrication is the key to reducing the wear by managing the friction,” John explains. “The right viscosity in the right application is crucial. If the viscosity is too light you get wear, if it is too heavy you waste energy. Just having the wrong grade of oil in an application wastes as much as ten percent of the energy consumed in a gearbox or motor.”

The final conclusions and report of phase one of this project are due soon and will be submitted to the Department of Science and Technology. “One of the main revelations is the fact that dirt ingress into machinery is prevalent in South Africa while the lack of training is a serious shortfall,” John says in conclusion. “Generally, people tend to start living with certain failures and then budget for them as running costs, whereas in actual fact, they should solve the problem from the start.”

John Fitton, SAIT, through the institute secretary at; [email protected]


SA Mechanical Engineer” visits Goscor Com-pressed Air Systems (GCAS), a newly-formed division of Goscor Power Products, which is now the sole distributor of the Sullair range

of air products from the USA. “Since setting up shop a couple of months ago we’ve already made significant inroads with both the compressors and the vacuum pump range,” says general manager of GCAS, Paul Combe. “Everyone is under pressure to be as efficient as possible and with the Sullair range of products we have a significant competi-tive advantage.

Redesigned range“The product has been on the South African market for many years, giving us a small market share to start off with, but we’re expanding quickly,” he adds. “There are certain niches in the market that others don’t cover, allowing us to make some headway with Sullair’s new range of Shoptek compressors that replaced the belt driven range it used to have. We’ve also had a good response from the hospital market in terms of vacuum motors and have already done several installations.

“For now, we’re concentrating on Gauteng and sur-rounding areas, but once established, we’ll extend our services to the rest of the country.”

The new Shoptek range is not only a more cost effective compressor, but it now has ‘extras’ built in as standard features. “Not only is it a better compressor, but it is more cost competitive to handle the flood of compressors coming in from China,” says Paul. “We’ve only just received the first stock of these new compressors and four have already been sold because the buyers immediately recognised the superior features.

Control system“With most compressors you have to purchase a separate panel to control multiple units,” explains Paul. “These control panels are sophisticated and expensive because they usually control up to seven compressors simultaneously. However, for

New Player in the Air Market

A comprehensive range of both compres-

sors and vacuum pumps, made by the same

manufacturer, is now finding a renewed

footing in the South African industry.

Stock spares for the new range of compressors

COMPRESSORS, AIR MOTORS & VACUUM PUMPS

It is more cost competitive to handle the flood of compressors coming in from China


Paul Combe

our specific market we only need to control two compressors at a time, therefore, Sullair redesigned a simpler built-in controller. Now it’s a simple matter of pre-programming the control according to customer requirements. This oil-injected rotary screw compressor is available in a whole range of sizes.”

Because compressors are huge energy guzzlers, all manufacturers have had to face the challenge of reducing energy consumption to the minimum. “All our compressor products have been redesigned, and are now seen as energy efficient machines,” says Paul. “They have two modes of operation. You can either run them under constant pressure, or you can have them load and unload which is where you save energy.

Saving energy“However, where required we can supply variable speed control systems,” Paul adds. “Using variable speed drives coupled with Sullair’s Smart Technol-ogy system, compressors can run more efficiently in environments where demand may vary from season-to-season or from shift-to-shift. In periods of low demand, the Supervisor control system reduces the compressed air output by reducing the drive speed. This reduction in drive speed saves power and trims operating costs.”

Another energy saving feature is a mechanical control system that continuously controls the ca-pacity in the compressor. “An outstanding feature of VCC (Variable Capacity Control) compressors is Sullair ’s unique capacity control system, which consists of a spiral valve and an inlet butterfly valve,” explains Paul.

Unique technology“This system delivers greatly improved part-load performance, especially when compared with compressors having suction throttling or load and no load controls. The compressed air volume is varied by rotating the spiral valve, which opens and closes by-pass ports in the stator, and returns air to suction rather than compressing it. By matching compressor displacement with output need, 17 percent less power is consumed.”

The range of two-stage tandem rotary screw com-pressors have been redesigned to feature variable capacity control with spiral valve technology to provide increased levels of energy efficiency and operating performance. They are available in either constant speed drive models or a range of vari-able speed drive (VSD) models. At full load, the tandem compressor and spiral valve have proven to be 13 percent more energy efficient, while at 60 percent load, the two-stage tandem compressors provide up to 30 percent savings over single-stage compressors.

More savings“Further part load and full load energy savings are achieved with an optional VSD which provides

This energy-saving system uses up to 17 percent less power

The product has been on the South African market for many years


the highest power factor over the entire frequency range,” says Paul. “This package, combined with the spiral valve, offers the best control with the lowest turndown in the industry, truly the ultimate energy saving feature in compressed air systems. The tandem compressor can also be fitted with a heat recovery enclosure which saves even more energy by recovering expended heat from the compressor. This heat can be used as supplemental comfort heating, or make-up air for process heating.”

In the future, GCAS will stock a wide range of portable compressors from Sullair. “With the new energy saving technology I am confident that this range of proven air products is set to grow in the local market,” Paul says in conclusion. “Just take the air-ends as an example of the quality of this premium brand. On a daily basis we hear of air ends that crash at anything between 20 to 25 000 hours. On our smaller units we comfortably get 45 000 hours while the bigger units do 80 000 hours and in many instances are still running.”

Paul Combe, Goscor Compressed Air Systems, Tel: (011) 453-8836, Email: [email protected], Website: www.goscor.co.za


Having been in the international compres-sor industry for 35 years, Geoff Houlgate, managing director of Kaeser Compressors South Africa, is just such a person. Five

years ago he came to South Africa to establish a wholly-owned subsidiary of Kaeser Compressors to service Africa. “SA Mechanical Engineer” joins him in Meadowdale near Johannesburg to chat.

In retrospect“When I got here from Kaeser in England five years ago it was like stepping back 20 years,” he says. “At that time, electricity was relatively cheap in

Europe and nobody was paying any attention whatsoever to the energy efficiency of machinery, but as prices rose they quickly got with the programme. Twenty years on and South Africa is now following suit as our equipment suppliers begin to educate end-users in the steps to take.

“In terms of efficiencies I’ve seen some diabolical local installa-tions,” Geoff says. “On every single installation and project that we’ve been involved in, we’ve been able to say right from the start that we’ll save the customer at least 25 percent. A high percentage of these savings come from purely looking at pipework and leakage in the reticulation system. After that, come other inefficiencies such as old units and compres-sors that haven’t been set up

correctly and so on.”

German precisionAs a German manufacturer, all machines made by Kaeser have matching components in order to achieve optimum efficiency. “Every machine that comes into South Africa for example, is fitted with an EFF 1 motor which already translates into a 6 percent saving,” says Geoff.

“The German philosophy is to educate users, not only about the efficiency specifications of our machines, but also about the crucial importance of correctly installing the system as a whole.

“For instance, we carry out surveys and audit installa-tions so that we can point out just how the end-user can save on an inefficient installation of which there are far too many in South Africa,” he adds.

In terms of efficiencies I’ve seen some diabolical local installations


Catch UpSometimes it takes an outsider to see the true situation and highlight faults that you don’t see as you’re too close to the subject matter. It may well be worth listening to such ob-

servations, especially if they come from a professional with many years of experience in the global arena.

The Kaeser Air Manager system

Geoff Holgate, managing director of Kaeser Compressors South Africa


1 bar equals a 6 percent electricalsaving


each pressure drop costs money. Another general problem we find in local installations is with drain-age. A solenoid switch is usually set on a timer and therefore it will discharge the condensate at preset intervals, together with compressed air, regardless of the amount of condensate that has built up. Our drains work on a sensor system, so the condensate is only released when it has built up to a certain level.

“With our compressors, like the downstream equipment branded under Kaeser, all these small issues that influence the efficiency of the system as whole have been taken into consideration.” Geoff says in conclusion, “We aim to provide an engineered solution to produce compressed air at optimum efficiency all the time. Too many people have taken compressed air for granted for too long. There are alternatives on the market today, unfortunately not all as efficient as they should be. Make sure you get help in designing your compres-sor installation, including the pipe network, which is as critical as installing the right machine for a specific application.”

Geoff Houlgate, Kaeser Compressors, Tel: (011) 974-5002, Email: [email protected], Website: www.kaeser.co.za

Split system“In the old days for example, companies used one main compressor with another on standby. The better installations would have two machines to produce air with a third on standby. Today, however, we opt for a split system where you have three to four machines, all differently sized, operated at a 0.3 bar differential by a controller that runs any combination of the units in order to meet the air demand. This is a further saving because 1 bar equals a 6 percent electrical saving.

“This is by far the most efficient way of produc-ing compressed air,” stresses Geoff. “Through the programming of the controller unit, you adapt the system to each individual requirement by running the machines at optimum efficiency levels all the time.”

Smart machinesModern compressors are sophisticated machines, much like the cars of today. They’re designed and built to last reliably longer with 3 000 hour service intervals and cannot be worked on by just any technician. “There are many people who work on compressors, repairing air-ends and the like, but in spite of knowing how to repair them, they simply cannot bring them back up to the original specifications. This alone contributes hugely to a machine running inefficiently, both in terms of power consumption and the output it delivers.”

In Geoff ’s book it’s all a matter of education. It’s often just small things that make an air system inef-ficient, but if you add up all the small faults, they amount to big losses, which can be easily avoided. “If you look at downstream equipment, there are many factors which clients should consider,” he explains. “The correct sizing of dryers and filters is critical, but in South Africa people tend to ignore, or simply don’t know how much influence these components have on the system.

Some of the faults“Take one simple, but very common problem which you’re likely to find at every local installation,” explains Geoff. “It’s the ninety degree elbow bend. A swept bend is far more efficient than a right angle bend which leads to a pressure drop, and

If you add up all the small faults, they amount to big losses, which can be easily avoided


Market ForumInnovative reconditioning solutionSKF’s Project Engineering Department successfully reconditioned a housing arrangement on a hot gas kiln fan application at one of South Africa’s leading cement manufacturing plants.

According to SKF Project Engineer, Niel Maree, the bearing that was operating within the non-drive end, solid type housing suffered a catastrophic failure and as a result, the housing fixing bolts were broken off and the housing lifted out of position by a bent fan shaft.

SKF was requested to perform the complete reconditioning within a very short time frame of five days”, reports Niel. The kiln fan bear-ings operate in a severely contaminated environment and in excessive heat. “It is therefore essential that contamination ingress be minimised”, explains Niel. Having conducted a complete design review of the through covers, Niel presented the customer with a long term, reliable solution which incorporated fabricated through covers with integral seals that were quick to manufacture in order to accommodate the tight delivery schedule.

“To improve the old gap seal mechanism on the existing through cover design, we integrated SKF’s locally-designed “taconite” type sealing arrangement with the new through cover design”, says Maree.

SKF South Africa (Pty) Ltd, Samantha Joubert, Tel: (011) 821-3500, Fax: (011) 821-3501, Email: [email protected], Website: www.skf.co.za

Mpumalanga Steam & Boiler Works, has recently completed the installation of a new steam boiler for Nelspruit Correctional Services in Mpumalanga. The new steam boiler is being unloaded here for Nelspruit Correctional Services

New prison boilerMpumalanga Steam & Boiler Works, specialists in the installation, repair and service of heat generation, waste management and energy production systems, has recently completed the installation of a new steam boiler at the Nelspruit Prison in Mpumalanga.

“This 1,8 ton coal fired steam boiler is designed for the generation and reticulation of sufficient steam throughout the building for the efficient heating of water for food preparation in the kitchen and to supply hot water to the ablution and laundry facilities at the prison,” says Nkosinathi Nkwan-yana, director, Mpumalanga Steam & Boiler Works, part of Advanced Industrial Technology (Ai-Tec).”

Because efficient boiler operation is critical for the smooth running of facilities like prisons and hospitals, the Department of Public Works, in conjunction with Mpumalanga Steam & Boiler Works, has embarked on a training programme for boiler operators. Training operations include lighting the fire for the boiler, raising steam pressure, de-ashing, emergency shutdowns, blowdown procedures and the safe maintenance of steam pressure.

Nkosinathi Nkwanyana, Mpumalanga Steam & Boiler Works, Advanced Industrial Technology (Ai-Tec), Tel: (013) 246-1722, Email: [email protected], Web: www.ai-tec.co.za

On the right trackKnorr-Bremse South Africa, manufacturers of train braking systems, has recently signed a BEE deal that at the stroke of a pen has changed the face of both the company and the South Africa railway landscape.

In an industry that has traditionally lacked active female participation, Knorr-Bremse has brought on board three dynamic black women who promise to change the way the male dominated rail sector is run.

The three women who make up the BEE consortium, Sonja Sebotsa, Polo Radebe and Raisibe Morathi have all been involved in various BEE transactions over the last decade and bring a wealth of experience regarding the potential pitfalls and positives relating to BEE and big business.

The deal, valued at R200 million over a period of 13 to 15 years, demonstrates the long term commitment of Knorr-Bremse to the South African economy.

The current BEE deal is not simply a paper transaction, the three women who form the backbone of the deal will have seats on the Board at Knorr-Bremse and will be involved in the day to day business in a high level advisory capacity.

Alois Adlkofer, Tel: (011) 961-7826, Email: [email protected], www.knorr-bremse.co.za

From left to right: Polo Radebe - Shareholder ICP, Alois Adlkofer - Managing Director KBSA, Ashley Emmerson - Member of the Board KBSA, Sonja Sebotsa - Shareholder ICP, Dr. Roland Klinkhammer - Vice President Corporate Legal and Patents – V/R KB AG


Market ForumSubmersible cutter pumpTsurumi Pumps South Africa has launched a high-head submersible cutter pump designed specifically for the sew-age market.

The new product, part of the C-Series family, completes Tsurumi’s line-up by meeting a clearly identified need for a submersible pump with the superior cutting capabilities and high-head pumping performance required for high lift applications and sewage transfer over long distances.

Target applications include the pumping of effluent from industrial and commercial complexes. A notably-improved cutting performance is the result of a re-designed wet-end that breaks up all foreign matter to prevent clogging.

Sintered tungsten carbide alloy blades have been integrated with the impeller vanes to allow them to act as a rotating cutter in combination with a suction cover that incorporates a serrated suction intake.

Both impeller and suction cover are made of high-chromium cast iron, ensuring excellent durability and enabling the pump to maintain high performance in high head applications for an extended period. Cutting efficiency is exceptionally high.

George Bath, managing director, Tsurumi Pumps, Tel: (011) 748-0200, Fax: (011) 421-2749, Email: [email protected]

The semi-open channel impeller and cutter mechanism of Tsurumi’s C-Series submersible cutter pump

Flanged connectionsThe Gemü range of manual and pneumatic angle seat globe valves are now available with flanged connections to EN 1092 and Ansi specifications.

Massive waterstorageGood news for would-be installers of very large panel reservoirs – water storage capacities are not limited

by the dimensions of standard production models.

Wayne Thompson, managing director of Rainbow Reservoirs, reports that the company’s Australian principals build to specification panel-type reservoirs as large as two megalitres for installation around the world.

“This is about three times bigger than the standard panel

The manually-operated type 507 and the pneumatically- operated type 514 with aluminium piston actuators, the 550 with stainless steel piston actuators and 554 with plastic piston actuators are now available with flanged connections in nominal sizes DN 15 – 50. The new flanged valve bodies are made of cast stainless steel 1.4435 (AISI 316L). Flanges are manufactured according to EN 1092/PN25/form B and ANSI class 125/150 RF specifications.

In order to be able to flexibly react to customer requirements in the most varied regions, the flanges are weld-ed on the basic cast bodies. This ensures good availabil-ity and short delivery times. Flanges are mainly used in industrial plant construction as they can be installed and removed more easily compared with butt weld and threaded con-nections. The valves are mainly used for control and regulation of steam, water

as well as slightly corrosive liquid media and gases.

Gemü Africa, Keith Hedges, Tel: (011) 462 7795, Email: [email protected]


Very high capacity panel reservoir

Market Forum

New meter distributorImpact Measurment Solutions is now the appointed South African distributor for the top quality range of flow mea-surement and control equipment and solutions from German company KEM Kueppers Elektromechanik.

Munich-based KEM specialises in the design and manufacture of a compre-hensive line-up of flow meters such as coriolis mass meters, gear, turbine, micro, turbidity and thermal mass meters. A full complement of associated equipment includes pickups and amplifiers, local display units, frequency to analogue converters, frequency counters and evaluation systems can also be supplied.

With distributors throughout the world, KEM ser-vices a wide range of industries including automo-tive, polyurethane, steel, food, pharmaceutical and petroleum where KEM flow meters are used on test benches, filling lines, batching and paint spraying systems.

Impact Measurement Solutions, Ken Falconer Tel: (082) 929-4128, Fax: 088 11 902 4679

Ship repair company considers the environmentDCD-Dorbyl Marine has reached an agreement with Total Cover SA, the South African appointed agent for Envirowrap International, an encapsulation and containment company, to provide environmental protection during the maintenance programme that is currently underway on the Saipem Saibos FDS vessel in Cape Town Harbour

This contract is a first in South Africa as a result of a huge amount of focus been placed on considering the environ-mental impact during a maintenance programme of such magnitude.

Maintenance areas are normally worked upon within the confines of scaffold enclosures with only limited environmental protection. The Envi-rowrap system vastly enhances the protection of the environment from maintenance waste,

reservoirs listed on company litera-ture,” says Wayne. “Enquiries for very large capacities are on the up, and I believe our designers at Heritage Tanks will soon increase the maxi-mum limit of 2 megalitres that they currently work to,” he adds.

Wayne says that the design of all Rainbow reservoirs is certified by a structural engineer, with manufacture carried out to the highest Australian quality control standards for applica-tions in forestry, mining, construction, general industry and agriculture.

Reservoir diameters are adapted to suit the space available on site, and the wall height increased to deliver the storage capacity required. The company recently used this method of adaptation to fit a reservoir into limited site space at a private hospital in Johannesburg.

Wayne Thompson, managing director, Rainbow Reservoirs, Tel: (015) 297-7640, Fax: (015) 297-7646, Email: [email protected]


Market Forum

The winner of the PneuDrive Challenge 2010 was announced in Johannesburg on 29 July 2010 after two days of judging by a panel of industry experts.

The University of Stellenbosch took the top spot for the third time in a row with their “Tshabalala Soccer Ball Shooting Machine”. The design was done by four Stellenbosch Me-chanical Engineering students.

The overall aim of the PneuDrive Challenge competition is to feature design innovation in the field of mechatronics and students engaged in the 2010 PneuDrive Challenge compe-tition were instructed to design an application using SEW Eurodrive and Festo products with this year’s competition theme being “motion in sport”.

The Stellenbosch team identified the training regimes of soc-

Ken Nixon (Wits), Chris Oliver (Festo Didactic) Dale Oosthuizen (Abtech), Norman Maleka (SEW Eurodrive), Antonie le Roux (Bate-man)

The winning team: Ivan Deetlefs, Thabo Mofokeng, Ryan du Ples-sis and Alex Oelofse – Mechatronic students at Stellenbosch University

Three in a row

cer teams as the greatest opportunity to design a “sporting solution with meaning,” which was additionally comple-mented by the excitement and enthusiasm created by the 2010 Fifa World Cup.

A possible shortcoming of many soccer training sessions could relate to goalkeeper and set-piece training. When goalkeeper training takes place, many players may be required to take kicks at a goal, often limiting their training time, and their incoming shots are in effect predictable. A machine designed by students from Stellenbosch University that can simulate set-piece training as well as generate random and unpredict-able kicks on goal could help teams maximise the training time of out-field players and heighten the effectiveness of goalkeeper training.

The user friendly application offers control of the system via a wireless console instead of a computer containing com-plicated software. This allows the control interface to seem like something “close to home” for a soccer coach.

The team worked under Professor Anton Basson who lead the two previous Stellenbosch teams to victory.

Sew-Eurodrive, Rene Rose, Tel: (011) 248 7000 Fax: (011) 248 7289, Email: [email protected], www.sew.co.za

which not only can pollute the air, but also has the risk of falling into the harbour’s water and subsequently flowing into the ocean

“Total Cover SA provides environmental protection of such areas by screening off and encapsulating, or shrink wrapping, the area while maintenance by means of sand/water blasting, grinding, welding and spray painting is being done,” says Total Cover SA spokesperson, Willem Botha.

Shrink wrapping is done around the scaffold areas and, in the case of the Saipem project, includes areas around the main deck of the ship, the deck cranes and cables.

This screening off and encapsulation of the maintenance areas allows for the waste from the maintenance projects to be contained, accumulated and disposed of under strict environmental control guidelines thus eliminating ocean and air pollution.

The high technology plastic material can be fully recycled and eventually used in the manufacture of plastic pipes. The material is also fire retardant and conforms to all ISO directives.

“Our product is a first for environmental protection in South Africa and promotes international best practices and standards that will change the way the industry approaches maintenance programmes with environmental impact,” says Botha.

Over and above the environmental benefits, productivity is also enhanced, in that little or no additional time has to be spent in having to clean working areas and equipment after the maintenance programme has been completed.

Total Cover SA, Willem Botha, Tel: (082) 458 8556, Email: [email protected]


Market Forum

Service life extensionDemands on universal joint shafts have increased signifi-cantly since the mid 1990s with torques and outputs in rolling mills nearly doubling over the past decade. New, high output motors and higher load collectives have a detrimental effect on universal joint shafts that have to transmit very high torque loads.

Furthermore, bearings in joint shafts are among the most negatively affected parts in the shaft and show the worst wear. Lubricants normally prevent metallic contact between the shaft body and the bearing track but in reversing joint shafts, the roller bearings rotate in alternative directions. In this application, conventional lubricants may prove to be inadequate, spreading away from the bearing and causing increased erosion.

Voith Turbo developed the WearCare 500 lubricant in co-opera-tion with a leading global bearing and lubricant manufacturer to meet these dynamic industry requirements. The result is a more effective option that features characteristics that far outweigh those of conventional lubricants.

WearCare 500 consists of lithium soap with unique additives to ensure that the lubricant adheres to the bearing surface. The lubricant is contained in the roll gap and metallic contact is dramatically reduced even with oscillating shaft bearings. Voith WearCare 500 lubricant demands a complex manufacturing process during which additives are carefully

Voith WearCare 500 high performance lubricant extend service life of bearings

Coal spiral pilot plantMultotec Process Equipment’s considerable success with its heavy minerals spiral plant led it to recognise the need for a similar plant in the coal industry.

The plant is equipped with a dewatering cyclone, a sieve bend and a bank of four Multotec MX7 spirals with the capacity to treat 36 tph of fine coal.

The plant processes fines, saving large volumes of coal which would normally be relegated to waste dumps. The fines are first deslimed with a Multotec desliming cyclone and then passed over a sieve bend to remove the +1 mm oversize material before being fed to the spirals. The plant is inclusive of pumps and sumps to feed the spirals.

“The pilot plant offers numerous advantages,” Renira Reddy, product manager:gravity con-centration at Multotec says. “It is easily dis-mantled, moved and re-erected thanks to its design as a moveable unit and is self-standing and engineered to be plug-and-play, though this depends on individual site conditions such as a ready supply of water as well as a tailings disposal set-up.”

“The pilot plant is trial erected prior to its transportation to site,” adds project manager, Gerhard Hattingh. “This enables the customer to give it a final inspection before moving it to site, virtually eliminating any teething problems associated with the structural layout.”

The coal spiral pilot plant is ideal for plants located in remote regions and can be employed as a pilot test unit. It is accessible to all miners and is particularly suitable for junior mining operations.

“Delivery time from order to delivery to site is no more than twelve weeks for deliveries within the

Gauteng region. In addition, return on investment is rapid, with capital outlay often being recouped within months,” says Gerhard.

Multotec Group, Bernadette Wilson, Tel: (011) 923 6193, Email: [email protected], www.multotec.com

A typical coal spiral plant

�� THE SOUTH AFRICAN MECHANICAL ENGINEER VOL 62 September 2010

Market Forum

Variable Height Extraction Valve (VHE) - cost and time efficient solution for effective pumping of mid water

Efficient removal of mid water“All sewage plants face the difficulty of effectively removing mid water or super latent that lies between the sludge and surface foam, so that the sludge can be dried. The common and widely used sluice plate method of removing mid water is not only impractical, but also expensive and time consum-ing. Often the plates get stuck when the sludge dries, which makes the entire process slow and laborious,” explains Piet van Vuuren, owner and member of South African company, Caretell Investments cc.

This problem is what triggered Piet to design, engineer and manufacture the Variable Height Extraction Valve (VHE), the only one of its kind currently available in the market.

folded into the basic oil and soap mixture. The lubricant is silicone and copper free for excellent erosion protection. Field tests, conducted over the past few years, have shown conclusively that WearCare 500 prolongs the service life of universal joint shaft bearings by up to 60%.

Used worldwide, Voith WearCare 500 is compatible with conventional, lithium saponified lube products, and even existing shaft bearings can be optimised by introducing this high performance lubricant. In addition, it is possible to extend lubrication intervals and even emergency operat-ing properties are noticeably improved after long periods without lubrication.

Voith Turbo, Roy Webster, Tel: (011) 418 4036, Fax: (011) 418 4080, email: [email protected]

According to Piet, the unique design capabilities ensure a cost and time efficient solution for the effective pumping of mid water.

“With the turn of a handle at the top of the 1.2m valve, the opening can be moved up or down the entire length of the valve to select the correct level of the mid water, which then drains through the opening,” says Piet. The VHE Valve is easy to install, does not require an external power source and poses no threat to the sensitive environment. He says that while only a manual option is currently available, electronic position selection options are being investigated.

The VHE Valve has already established an excellent track record in its very short history and two sewage plants in Oshoek in the Free State and Beit Bridge have each installed two valves which are operating successfully. When the two plants recognised the time and cost saving implications of the VHE Valve, they took the decision to replace the high maintenance sluice plate system. Both facilities are more than satisfied with results, reporting cost and time saving due to decreases in downtime, maintenance and operating costs.

Caretell Investments, Piet van Vuuren, Tel: (072) 1991223, (079) 5235859, Fax: 0865754111, Email: [email protected]

New axes designFesto, supplier of automation solutions, recently launched the EGC electric drive range that delivers increased perfor-mance for the motion control industry and features a new profile design.

Not only do the new axes perform between 100% and 700% better than previous generation coun-terparts, they also cost 10% less.

During its Research & Development programme aimed at improving the performance and service life of its electro-mechani-cal drives, Festo looked at Italian master Leonardo da Vinci’s Cupola arch for inspiration.

“The main body of every EGC axis is constructed from extruded aluminium, with a computer optimised cross-sectional shape that incorporates an internal arch-shaped structure. This feature provides the drives’ rigidity and load


Market Forum

The new range of EGC electric drives from Festo features a radically new profile de-sign, performs between 100% and 700% better than previous generation counterparts and costs 10% less

bearing capabilities for very low mass,” explains Ernst Smith, Product Manager – Electronic, Festo.

Feed forces as high as 3 000N and speeds of up to 5 m/s, as well as new levels of acceleration and torque resistance, make them ideal for use in gantry-type materi-als handling, supplying and transporting systems.

The moving carriage is fitted with high performance caged ball bearings, and the fully sealed bearing cassette has grease pockets for optimal lubrication. Festo also offers a number of optional guide scrap-ers and grease feed adapters for use with centralised lubrication systems. The top face of the aluminium carriage is fitted with helicoils and centring holes to facilitate fast and accurate load mounting.

A choice of toothed belt or ballscrew drive mechanisms, with numerous variants in both categories, makes it easy to choose an actuator optimally matched to application needs. “Unlike most competitive products, the axes’ stainless steel guide rail is mounted externally, al-lowing the moving carriage to accommodate large cantilever and offset loads that apply very high moments of torque to the carriage,” says Ernst.

The toothed belt version of the EGC axis is available with a choice of 50, 70, 80, 120 and 185 mm wide profiles, and the three largest models can be supplied with standard stroke lengths of up to 8.5m. Different models within this range are capable of generating feed forces as high as 2 500N and of handling speeds up to 5 m/s and accelera-tion rates up to 50m/s².

Festo, Joanne Dexter, Tel: (011) 971 5560, Fax: (011) 974 4203, Email: [email protected]

250 000th skid steer slips of production line “In 2000, the 100 000th skid steer was manufac-tured and ten years later, Case has more than doubled global sales,” says Rod Watson divisional director of CSE Equipment’s construction division. “All terrain Case 430 series 3 skid steer loaders have been designed for exceptional driving force.

Turbocharged, four cylinders, Tier 3 certified diesel en-gines, which provide the power and torque required to efficiently cope in the toughest site conditions, also ensure operating efficiency and fuel economy. High torque power ratings provide sufficient rim pull to keep the machine moving and recovering in arduous environments.”

These versatile skid steers have more than 75 attachments for efficient digging, hauling, pushing and loading material on job sites in diverse industries, including mining, construc-tion, cement, steel, agriculture and landscaping.

Optional attachments like buckets, pallet forks, breakers, augers, sweepers, backhoes, stump grinders, cement mix-ers, cold planers, trenchers, rollers and slot cutters are available.

Case construction equipment, available exclusively from CSE Equipment Company in Southern Africa, includes loaders, backhoe loaders, excavators, telescopic handlers and skid steers.

CSE Equipment Company, Rod Watson, Tel: (011) 922 2000, Fax: (011) 922 2108, Email: [email protected], www.cse.co.za

The 250 000th Case 430 series 3 skid steer loader has just come off the production line


Market ForumEasy customisation with MPS solutionSole distributor of Bosch Rexroth products in southern Africa, Tectra Automation, recently supplied Centurion Systems with a customised, product specific manual production system (MPS) to improve the production of electric gate motors.

The products from the MPS range assist in manufacturing an ergonomic product through the correct lean processes. The MPS system is based on the Japanese kaizan principle for production, which focuses on continuous improvements in processes in manufacturing or engineering.

“MPS products save time, prevent errors from occurring and eliminate over-processing, production and movement that does not add value,” explains Kevin Lombard, General Manager, Tectra Automation.

The objective of MPS is more added value, instead of inefficient work processes and the main focus of the new development is on flow rack systems and solutions for material supply.

A new material shuttle provides material quickly and clearly on the rear of the manual workplaces which enables short set-up times with multiple models. The flexible lean flow rack system visualises the actual inventory at a glance through coloured rollers, this avoids having too much material in the production flow. The flow rack systems are ESD-compatible and can deal with loads of up to two tonnes.

Characteristics such as dimensions, material or design are defined in parameters and each function module contains all the individual components that comply with the parameters In terms of size, form and quantity. The system includes workstations with accessories, as well as modules for mate-rial supply (flow racks, material shuttles or grab containers) plus material flow and linking components.

Tectra Automation, Kevin Lombard, Tel: (011) 971 9400, Fax: (011) 971 9440, Email: [email protected]

On the Move

Bellambie Mining & Industrial has appointed Seuntjie Soke as lifting inspector.

IndextoAdvertisers

AES 24

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Multi Alloys 12

Multotec Inside Back Cover

Munters 8

Producut Lubrication Technologies 27

Yellotec 14, 29

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