THE SOUTH AFRICAN MECHANICAL ENGINEER
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May 2010
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THE SOUTH AFRICAN MECHANICAL ENGINEER
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May 2010
AN ENGINEER’S VIEW
Infrastructural Entropy
Chairman of the Working Committee: Communications (SAIMechE)
Chris Reay
I guess it would be futile to try and educate politicians about the concept of entropy because it is a scientific and engineering term that would immediately send them off on their next overseas trip to rather pursue some pointless and costly party interest. How else does one get the message across to them that unless they put some energy into the closed system called the county’s infrastructure consisting of engineered assets, constructed facilities and orderly management, then the system will continue to lose any contained energy until it reaches equilibrium with nature’s random “chaos”?
awarding of tenders is also a cause of concern. In fact it is rampant.
A
disturbing recent commentary from the civil engineering profession contains a number of serious issues that illustrate the growing loss of skills and institutional energy from the infrastructure. Consider some of these: • Safcec (The SA Federation of Civil Engineering Contractors) says a large number of contract awards are being postponed by all tiers of government, while technical expertise is also lacking at government level to make the necessary decisions on project scopes and the awarding of tenders.
Leading indicator
Bureaucracy, politics, finger trouble and plain stupidity reign supreme
• It is not that government does not have the money – it is that they are not spending it. One infrastructure agency had access to R27-billion in credit, but used only R300-million. • Overall, the tender adjudication postponement rate for the government sector on the whole, across all tiers, increased from 10% in the fourth quarter of 2008 to 23,2% in the fourth quarter of 2009. • Where it should take around three months to award a tender, it can now take up to a frustrating six months, which means skills and capacity in the industry lie dormant. • A recent report on municipalities says the combination of poor payment and higher levels of postponement suggest either a funding or management issue, both implying capacity constraints. Evidence of this is the latest municipal financial report, ending December 2009, which shows a debtor analysis in excess of 70% at 90 days or more, across all municipal departments. • Safcec adds that there is too much political involvement in decisions that should be driven by business principles, especially at local municipalities and parastatals. Corruption in the
We know that the civil engineering profession tends to be a leading indicator of the project spend pattern. How will this impact on the mechanical and electrical professions? When local skills capacity lies dormant it will seek work outside the country, and coupled with the general skills shortage across most sectors, even in the unlikely event that the politicians do understand the second law of thermodynamics, then they will find that the source of providing the required energy has left home. The Local Government SETA’s own scarce skills list shows “absolute scarcity” ranking in all disciplines of engineering. Yet when one develops a programme to assist in the relief of this skills need, bureaucracy, politics, finger trouble and plain stupidity reign supreme. I would to know if the Planning Commission which has taken so long to get its own planning act together, if at all, is actually aware of the impact of a declining infrastructure and what they plan to recommend. The evidence now becoming common knowledge is the number of municipalities where the residents are forming their own bodies to run the local authorities’ affairs. As institutional memory and capacity decline, the citizens will take over to maintain any sense of stability and control. The ANC may just realise in due course that this is not good for voter support, and entropy cannot be reversed by denial and inactivity. In the end, engineering skills will be the essential midwife to help with the birth of a new dispensation for the reversal of the energy loss. It is really that which creates the built environment.
THE SOUTH AFRICAN MECHANICAL ENGINEER
VOL 60
May 2010
State-of-the-art manufacturing plant backed by strong technical expertise
Our 27 000 m2 manufacturing facility is designed to satisfy the biggest high quality fabrication needs locally.
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37 Homestead Road, Rivonia, South Africa Tel: +27 11 806 3000, Fax + 27 11 806 3330 e-mail:
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THE SOUTH AFRICAN MECHANICAL ENGINEER
VOL 60
May 2010
May 2010
VOLUME 60
NUMBER
Featured on the Cover
Maizey Engineering Plastics Tel: (012) 352-2000 Email:
[email protected]
Contents
Monthly Column
8 Hooked on Bass
Filters & Filtration
27 Half Price is Half Performance 31 Every Drop Counts
10 Letter to the Editor Cover Story
11 Coming of Age
Steam, Turbines & Boilers
33 Saving on Process Energy and Steam
Power Transmission
15 Smoothing the Way 17 Die-hard Survive Copyright
All rights reserved. No editorial matter published in “SA Mechanical Engineer” may be reproduced in any form or language without written permission of the publishers. While every effort is made to ensure accurate reproduction, the editor, authors, publishers and their employees or agents shall not be responsible or in any way liable for any errors, omissions or inaccuracies in the publication, whether arising from negligence or otherwise or for any consequences arising therefrom. The inclusion or exclusion of any product does not mean that the publisher or editorial board advocates or rejects its use either generally or in any particular field or fields.
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Regulars
3 6 13 26 37 46 An Engineer’s View Institution News Consulting Engineers SA Nuclear Institute (SA Branch) Market Forum On the Move
POWER GENERATION TODAY
21 Creative Co-Generation 24 Power Generation News
The monthly circulation is 4 242
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THE SA INSTITUTION OF MECHANICAL ENGINEERING
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
THE SOUTH AFRICAN MECHANICAL ENGINEER
VOL 60
May 2010
THE SA INSTITUTION OF MECHANICAL ENGINEERING
Technical Consultant
Malcolm Black developer & Presenter of “The Engineer As Manager” Workshop and the Presenter of the Steam Series Workshops Malcolm Black, B.Sc. (Mech. Eng.) from the University of Witswaterand (1973), Bachelor of Theology (Th.B. ) form Rhodes (1977), Government Certificate of Competency (1982), has worked firstly as a Student Engineer - Anglo American Research Laboratories, Crown Mines and then as a Manager
Malcolm Black The South African Institution of Mechanical Engineering Training Events Calendar: June - July 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. All events are CPD validated. A registration form and full terms and conditions may be obtained from Carey Evans on E-mail: carey@ saimeche.org.za or Tel. 031-764-7136. Also, detailed individual event programmes are available from Carey. Corporations wishing to book InHouse Workshops may contact Linda Robinson on E-mail:
[email protected] or Tel: 031 764 7136. Event Code Full Title Date - Start Region F2810 Introduction to Wear & Materials 09-Jun-10 Secunda D2810 Introduction to Wear & Materials 23-Jun-10 Vereeniging J2710 Philosophy of Mechanical Maintenance 14-Jul-10 Pretoria D0410 Steam Trapping; Condensate Removal; Condensate Recovery 14-Jul-10 to 15-Jul-10 Vereeniging C3610 Project Management - A Review of Essentials 15-Jul-10 Cape Town D3110 Heat Transfer in Practice - Via Conduction & Convection 21-Jul-10 Vereeniging F0410 Steam Trapping; Condensate Removal; Condensate Recovery 21-Jul-10 to 22-Jul-10 Secunda D3210 Heat Transfer in Practice - Evaporative Cooling & Drying Processes; Radiant Heat Transfer 22-Jul-10 Vereeniging
and/or Engineer in a number of companies All these positions required the use of management and technical skills in order to get the required tasks done and produce the necessary bottom line results. All management skills were obtained in practical situations and developed with plant and business performance in mind. Malcolm serves on the KNZ Branch Committee and is a highly esteemed honorary consultant to SAIMechE on technical training matters.
Council 2009/2010 Office Bearers
President .................................................. G Barbic (George) President Elect ............................................. D Findeis (Dirk) National Treasurer ................................. K Nyangoni (Kudzai)
Company Affiliates
Branch Chairpersons
Central ...................................................... M Cramer (Mike) Eastern Cape ............................. Prof Dr DG Hattingh (Danie) 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]
Ainsworth Engineering 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 KHD Humboldt Wedag SA Megchem Eng & Drafting Services 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 May 2010
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THE SOUTH AFRICAN MECHANICAL ENGINEER
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May 2010
MONTHLY COLUMN
Hooked on Bass
Bass has become the second most sought-after game fish in the United States where the sport has driven the development of all manner of fishing gear, including rods, reels, lines, lures, electronic depth and fishfinding instruments, drift boats, float tubes, and specialised bass boats.
and equipped primarily for bass fishing in freshwater such as lakes, rivers and streams. The modern bass boat features swivel chairs on a flat deck that permits the angler to cast to any position. It has plenty of storage bins for fishing tackle and equipment such as rods and lures, and a live well with re-circulating water where caught fish may be stored and kept alive. Bass boats are usually propelled by two means, an outboard motor which moves the boat swiftly from one place to the next while an electric trolling motor allows for quiet manoeuvring through a likely area.
“SA Mechanical Engineer” speaks to professional bass fisherman and boat builder Allen Fagan of Predator Bass Boats near Vereeniging about bass boat design in general. “I’ve been fishing since I could hold a fishing rod as a youngster and my dream has always been to design and build the ultimate bass boat,” he says. “After Allen Fagan (right) with Shandon Hawman of Boatcenter who sells bass boats throughre-settling in South Africa from Zimbabwe, out South Africa this opportunity presented itself as there simply wasn’t scope for another boat builder in ass fish are predators and not easy to catch, but once you’ve hooked one it puts Zim, but here it’s a constantly growing industry up a long and hard fight, adding to the and I seized the opportunity to get into bass boat excitement that has made it the popular manufacturing.
Pro fisherman
B
sport it is today.
You often have to travel long distances over choppy waters to get to the right fishing spot
The boat
om One of the ‘tools’ bass fisherman rely s fr ff e r on heavily, besides a huge art di oa sb ray of colourful lures bas fa lo that are dipped hul The in any number of exotic flavours is the boat. Although there is no rule to say you can’t fish bass from a small flat-bottom dinghy, proper purpose-built bass boats have become the ultimate accessory, even for the casual bass fisherman.
“My first design, the Rogue, is a 19 foot fibreglass boat that took about three-and-a-half years to develop
boa ts
oth
er
ed spe
A bass boat is a relatively small vessel designed
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MONTHLY COLUMN
before we built the first one,” Allen says. “It sold immediately and since then business snowballed as local fisherman started looking for high quality workmanship in a dedicated bass boat. From the beginning, we aimed at reaching the American standard in finishing as they’re the trend-setters when it comes to purpose-built boats.”
of the champion bass catches in Zimbabwe, for instance, was caught off a dug-out canoe with an ordinary fishing rod.”
Allen Fagan, Predator Bass Boats, Tel: 082-650-3379, Email:
[email protected]
High performance
“The main difference between a bass boat and an ordinary speed boat in terms of design is the fact that the top deck is usually flat on the bass boat in order to provide space for the constant casting of bass fishing,” explains Allen. “In addition, bass boats are now high-performance vessels because you often have to travel long distances over choppy waters to get to the right fishing spot and you want to do that quickly but in comfort and without endangering your life. “Today’s bass boats can do 140 kilometres per hour and therefore it’s not a boat you fool around in just for the fun of showing off to your friends,” says Allen. “For this reason we’ve changed the hull’s hydrodynamics to lift the hull out the water when The live well is an important feature on a bass boat travelling at high speed. On the older designs you lost a lot of power because the hull forces water outwards, whereas our design pushes the water down to lift the hull out the water. Of course you then have to consider aerodynamics because the hull is exposed to air.”
Not a boat you fool around in just for the fun of showing off to your friends
Gadgets
Of course, the science of bass fishing requires special tools, so the boat can be fitted with a wide choice of electronic gadgets to help the fisherman achieve his goal. “The main aim of a dedicated boat is to provide you with comfort while you troll the fishing area with the electric motor which is steered and controlled by foot pedals,” explains Allen. “However, for those with enough money there are dedicated GPS systems, water temperature measurement instrumentation, depth meters, colour screen scanners and many other gadgets to make the experience more interesting. “With these gadgets you can today literally ‘see’ your lure under the water, where the fish are and whether they’re interested in your bait,” he adds with a chuckle. “However, this still does not make you a better fisherman and ultimately it is each person’s skill that lands the big one. Ironically, one THE SOUTH AFRICAN MECHANICAL ENGINEER VOL 60 May 2010
A comfortable seat for a long day’s hard work
LETTER TO EDITOR
Letter to Editor
An engineer’s view
When I receive “SA Mechanical Engineer” the first article I read is “An Engineers View” which happens to be on the second page but I would still read it first if it was on the back page. I have to congratulate Chris Reay on his assessment in the latest issue where he slates the Government for their tardiness and in particular the Ministers who are supposed make things happen. He is absolutely right. The Eskom debacle is one I foresaw happening many years ago and which has since escalated by the replacement of experienced personnel with people who do not seem to have the vaguest idea about what has to be done. It is no wonder there are problems and indecision. Perhaps it is not too late to get matters put right but it will take a lot of pressure from many people like Chris to bring home that the African way of doing things cannot work when it comes to sophisticated infrastructure. It is difficult to see it coming right and it may have gone too far in view of the lack of available skills. The Government’s pigheaded attitude by replacing skilled personnel with incompetent and inexperienced people who seem to be selected by African standards which end in disaster and the unsatisfactory situations we are seeing every day. It goes right down, for example, to the sub economic housing issue which should be a relatively straightforward process but it is fraught with problems. What a mess!! The dice seems to be stacked against the people who could make it happen.
David Rose
Engineer Placements
Our job board continues to display a wide variety of excellent job positions that you can review and apply for on-line. Keep your credentials on our secure and confidential database. We include the projects for: Eskom, Gautrain, PBMR, The SA Oil and Gas expansion, and International options.:
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THE SOUTH AFRICAN MECHANICAL ENGINEER
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May 2010
COVER STORY
Coming of Age
Rikki Maizey, managing director of Maizey
“Although it was a family business, the rule from the beginning was that family draws a salary like everybody else in the company and the balance goes back into the business to fund growth. “Over the years we invested a lot into property, not as a business in itself but rather to own the premises we operate from. We’ve also had a few lucky breaks over the years, simply by having the right product available when people started asking for it.”
Products from the engineering workshop
The tradition of celebrating a 60th birthday, or Diamond Anniversary, came into popularity after Queen Victoria celebrated her Diamond Jubilee. Diamond comes from the Greek word ‘adamas’ which means unconquerable and enduring, making a 60th anniversary a milestone of endurance in the life of any person, relationship or company.
Perspex
T
his year the Maizey family’s plastics business celebrates its 60th anniversary and to review the milestones “SA Mechanical Engineer” speaks to Rikki Maizey, managing director of Maizey’s (Pty)Ltd, an Engineering Plastic Products supplier in Pretoria. “What my grandfather started as a one-man business in a small handcraft die-sinking shop on the corner of Boom and Shubart streets in Pretoria is today a business of 21 branches spread across South Africa,” he says. “It is great to be part of such a legacy which we’re all very proud of today.
Rikki’s father joined Rikki’s grandfather at the age of 16 in the mid-fifties at a time when Perspex emerged as a tough material that could also be used for more than just aircraft canopies. “Customers started using Perspex in the engraving business as well, and soon we became an agent for the manufacturer in England when the local suppliers of Perspex closed down,” explains Rikki. “Our first shipment from ICI was ten sheets of Perspex because that was the minimum you could order at the time as a distributor for the company.” Also at this time, the Pelindaba nuclear facility was being built east of Pretoria and Maizey’s first order for engineering plastics came from this contractor. “By word of mouth it had become known that we were supplying Perspex and other building-related plastics,” recalls Rikki. “John Maizey, my uncle, had just joined the company from Woolworths and was responsible for marketing when he got a by-chance call from Pottie Potgieter at Pelindaba who wanted certain plastics that we’d never even heard of. John didn’t let the chance slip by and made it his business to find out more about what they wanted and set about sourcing it.” VOL 60 May 2010
Family draws a salary like everybody else in the company
The basis
“The success of this business can be ascribed to the financial discipline philosophy my grandfather established right from the start,” adds Rikki.
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COVER STORY
Support
“This was our introduction to engineering plastics, paving the way for a long relationship with supplier Erta Engineering Plastic in Belgium and kick-starting our distribution business in engineering plastics in South Africa,” says Rkiki. “Erta came out here, trained our staff to understand the technicalities of engineering plastics and provided constant support in many forms over the 30 years that followed. This boost in the Pretoria business allowed us to expand and we soon opened our first branch in Primrose in Johannesburg, a huge move for us. You must understand that Primrose was miles away in those days.”
rable milestones was when the technicians in the engineering workshop came up with a solution to make the bushes for underground locomotives more cost effectively. “You had to use a large chunk of material and then machine off a lot of material to form the large flange of this bush,” he explains. “We custom-rigged a friction welding system whereby a tube could be welded onto the flange, thereby saving significantly on waste. Through Erta we shared this with the international plastics industry and were praised for the concept.” But it wasn’t always plain sailing for Maizey. Rikki’s personal biggest disappointment was when a joint venture with another plastics engineering company did not materialise. “This company was ailing already and would have complemented the engineering side of our business perfectly,” he says in retrospect. “Although the concept was good, red tape in the end killed the venture and led to the engineering side of our business declining dramatically with only the distribution side growing steadily.”
Although the concept was good, red tape in the end killed the venture
One of the highlights for Rikki stems from a competition a local newspaper ran in the 1992 to list the top unlisted companies in South Africa. “We were encouraged by our bankers to enter for this award and we ended up in the top ten finalists,” recalls Rikki. “It was the first and only time we’ve ever entered such a competition and just the fact that we were in the top ten was good enough for us.”
Engineering
Ingenuity
In terms of engineering one of Rikki’s most memo-
The engineering side, as in providing a service to design and machine plastic parts, has always been Rikki’s passion and over the past two years he has revived this side of the business by establishing a dedicated engineering workshop in Wadeville. “Maizey Engineering is now an established business equipped with the engineering expertise that will re-establish us to bring engineered plastic solutions to the market,” says Rikki. “I am optimistic that we’ll see rapid growth in this business especially as we’ve invested in modern machinery to manufacture intricate plastic components for all industries.
Capital investment
Today’s modern Maizey shops
The new engineering facility is equipped with both modern CNC routers ; a CNC lathe, and conventional wood and metal working machines, modified to accommodate the specific requirements of machining engineering plastics. “The establishment of Maizey Engineering represents a significant capital investment as part of the Maizey group’s ongoing commitment to provide a complete service to the South African market,” says Rikki. “As an integral part of our comprehensive engineering plastic’s solutions package, the now established machining facility allows us to provide finished components in wide variety of formats and geometries to close tolerance dimensions, including design assistance for gears; sheave wheels; pulleys; bearings; bushes; non standard chain guides and various other components.
Evolving with the market
“Over the past sixty years we have grown with South African industry by making changes and evolving with the market,” says Rikki in conclusion.
The first Maizey shop in Pretoria
Rikki Maizey, Maizey Engineering Plastics, Tel: (012) 3522000, Email:
[email protected]
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CONSULTING ENGINEERS SA
Procurement policies and guidelines published by the Construction Industry Development Board (CIDB) are among the best in the world. However, for a variety of reasons many clients and consulting engineers do not apply these when procuring service providers.
P
Head-on
states, “Some of the issues that are being addressed include dealing with an inadequate brief; allowing sufficient time from the request for proposals to the closing of the tender; understanding the BBBEE scoring system; understanding the reason why tenders may not be re-issued within a 6 month period; the issue of unlimited liability; and the implications of working at risk.”
rocurement within the South African infrastructure environment has long been a contentious issue with an array of vastly differing policies and procedures making it difficult for both consulting engineers as well as their clients to make an informed and equitable decision in this regard. Consulting Engineers South Africa (CESA) has embarked on a nationwide campaign, visiting all nine regions, to inform and educate on Procurement best practice for members and public sector clients thus ensuring that our taxes are spent effectively. CESA in consultation with the CIDB as well as industry experts has developed a Best Practice Zulch Lotter, CESA President Guideline for the Procurement of Consulting Engineering Services that is in line with the latest legislation, including the Construction Sector Charter.
Roll-out
The CPD accredited technical briefing provides delegates with the opportunity to workshop national and international best practice with experts. The briefing unpacks the procurement of consulting engineering services and delegates attending the briefing will be issued with best practice guidelines in this regard. The content of the Manual and the Technical Briefing focuses on the full lifecycle of a project as well as the role of both the client and the consultant. This includes the monitoring of consulting engineering services by the client.
For the programme details please visit www.cesa.co.za or contact, Graham Pirie, Consulting Engineers South Africa (CESA), Tel: (011) 463-2022, Email:
[email protected]
Working at risk
Wally Mayne, CESA’s Contractual Affairs Manager
Understanding the reason why tenders may not be re-issued within a 6 month period
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POWER TRANSMISSION
Smoothing the Way
unit. Yet they had to build a small gearbox to fit into the confined space available. Also it had to be extra heavy duty to withstand the erratic varied loads and high temperatures of a wind turbine while lasting several years with the absolute minimum maintenance.
Challenges
In turn, lubrication manufacturers were challenged to come up with a suitable solution for the gears and bearings in the specially-developed gearboxes used in wind turbines that work around the clock in remote locations where it is very difficult to carry out regular maintenance. This was promptly done and today these highly specialised lubricants, originally developed for wind turbines, are now also available for general industrial gearboxes.
Special research into lubricants that could resist grey staining
Charles Du Bois, business development manager at Status Industrial Solutions, a division of Chemserve Systems
New technology invariably has a rippling effect down the line. A static gearbox on a constant power source, for instance, needn’t be as tough as one that has to cope with variable loads, higher speeds and less maintenance.
A
s the need for alternative energy sources emerged, for example, and wind turbine technology started evolving to improve the performance of these large machines, it challenged gearbox manufacturers to come up with a solution for a dedicated high-performance
“SA Mechanical Engineer” speaks to Charles Du Bois, business development manager at Status Industrial Solutions, a division of Chemserve Systems who played a core role in developing the new lubricants for wind turbines. “During this development phase, new phenomena in terms of gear wear were discovered,” he says. “One of them is micro pitting, also called grey staining, found after examining the gears in wind turbine gearboxes frequently over short intervals to try and get to the problem of constant failure in this specific application.
Pitting
“Until then, the inspection intervals on the gear wear had been too long and the wear too far gone to notice the micro pitting, but when we started doing more frequent inspections under the microscope, we found the grey staining on the gears,” Charles explains. “This turned out to be micro pitting which prompted the FVA (Forschungsvereinigung Antriebstechnik), the German Transmission Engineering Research Association, to start special research into lubricants that could resist grey staining. Through additive technology, they developed specifications for these special lubricants which today are the norm for wind turbine and other heavy duty gearboxes. “Although there were high performance lubricants with EP (extreme pressure) and molybdenum disulfide additives around at the time, these technologies had reached their limit in terms of resisting micro pitting.” explains Charles. “The research and development departments of Optimol and Tribol opened up new research paths independent of each other to search for particularly effective additive systems and came up with new additive combinations which generate a smoothing effect in the micro range called Microflux Trans and TGOA. VOL 60 May 2010
A clean sliding surface (left) and on the right a corroded surface
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adds Charles. “At the same time the specific surface pressure and the coefficient of friction, are both reduced significantly.”
The stages
Stage one of the formation of a protective layer
The first stage of the process is where a protective layer forms due to the pressure resistant additive combination. Stage two is the compression of the protective layer where an increasing load compresses the layer to become even more pressure resistant while simultaneously improving the coefficients of friction. “The third stage consists of micro-smoothing representing the actual unique performance of these high performance lubricants,” explains Charles. “As the pressure further increases, special additive components migrate from the deposited protective layer into the structure of the metal surfaces, thus initiating the micro-smoothing effect. “At the same time reaction products are produced which contribute to the formation of extremely adhesive tribopolymers with excellent sliding properties. These form an additional, extremely pressure-resistant protective layer,” says Charles. “During the smoothing effect, the metal surfaces are leveled which results in a considerable decrease in the coefficient of friction.”
Stage two, compression takes place
Repairing
Final stage of the micro smoothing process
In South African industry, awareness of the characteristics of these high performance lubricants has grown steadily and many companies are on board, but lately new characteristics have come to light which are bound to interest even more people. “It looks like these oils are ‘repairing’ existing pitting as well,” says Charles. “The pitting won’t disappear by using the lubricant, but these new products have now been proven to smooth the sharp edges in a pitting. Normally the sharp edges escalate wear, but the smoothing effect seems to arrest wear. “And we have seen this with our own eyes when we changed to high performance lubricants for a gearbox in the vertical mill at a South African cement plant,” adds Charles. “The wear rate was so high the filter had to be changed on a daily basis. Since we changed the oil, this gearbox has been running for over six years without any of the problems and failures previously experienced by the client.”
New additives
“The basic principle behind these additive technologies results in the improvement of the surface quality without depositing or removing material,” elaborates Charles. “These state-of-the-art additive technologies adjust themselves even more selectively to the changing loads in the lubricated system. The stressed surface is smoothed in the micro range by an almost non-sacrificial, physical chemical three-stage reaction. When it comes to countering the frequent grey staining gear damage, the micro-smoothing action of these lubricants offers very effective protection.”
Engineering component
It looks like these oils are ‘repairing’ existing pitting as well
This three-stage process is also referred to as Surface Engineering (SE) or Plastic Deformation (PD) and was confirmed by the FVA in various research projects. “The high performance lubricants with Microflux Trans and TGOA technology of Castrol Industrie can increase the load bearing surface area of the lubricated components up to eighty percent,”
One of the most common mistakes engineers make in terms of gearbox problems is to look for the cause in the wrong place. “We had a case where they were about to fit coolers to the gearboxes on a plant at a huge cost due to constant temperature problems,” says Charles in conclusion. “It turned out to be a lubrication problem where high friction increased the temperature. By changing the lubricant to reduce friction, we saved them millions. Lubricants should be considered as an engineering component and not just as a commodity as is generally the practice.”
Charles du Bois, Status Industrial Solutions, Tel: (011) 9221842, Email:
[email protected]
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Die-hards Survive
Old gearboxes never die, they often get a second or sometimes even a third lease on life with brand-new innards and a shiny new coat to look like the day they came out the factory forty or fifty years ago. Some of them are so old that there often aren’t any spare gears available to restore the innards, so these then have to be made from scratch.
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company that specialises in gearbox rebuilds and refurbishing is Industrial Gearbox Services (IGS). To get the inside story, “SA Mechanical Engineer” speaks to Fanie Kruger who runs the factory in Sebenza
near Kempton Park. “We work on all makes of gearboxes and regularly come across old types like the Radicon side-shaft gearboxes that date from the sixties,” he says. “They were widely used in underground mining applications and often the owners would rather have them refurbished than replacing them with new ones.
No spares
Including a couple that are ready to go out to replace fellow cronies that need rejuvenation
“While bearings for the older gearboxes aren’t a problem, OEMs often don’t have spare gears for the older models, so we have them made according to the required specifications by specialist machine shops equipped to do high precision gear cutting,” says Fanie. “Many times the gears are so worn, especially when it comes to brass gears, that we have to get a design engineer in to draw up the specifications for the cut.” To show us, Fanie walks us through the workshop where, among other makes, we see several Radicon gearboxes in various stages of rebuild, including a couple that are ready to go out to replace fellow cronies that need rejuvenation. “Our run-of-themill repair work on gearboxes is replacing bearings as they fail first when people neglect maintenance,” he says. “We’ve opened gearboxes here that don’t have a drop of oil left, just a thick grimy paste left behind in the sump. And then people are surprised that the bearings fail.”
Brakes and motors
Servicing and rebuilding gearboxes isn’t IGS’s only business. “We have over 22 years experience in the field and take great pride in our service and strong after sales support,” says Fanie. “Besides working with motors and gearboxes that vary from small, off the shelf units, to specialised, custom built power station units, we also remove and refit brake motors, fit forced ventilations to motors, do the extension of fan cowls and manufacture belt guards and base plates for drive installations. “We go beyond pure repair and refurbishment and what we can’t buy, we manufacture.”
Fans
New electric motor being fitted with a brake system
The company designs and makes forced ventilation systems for a broad range of electric motors. Most of the OEM suppliers of electric motors send their motors to IGS where they design and fit a cowling, independent fan and motor to the end of the electric motor for extra cooling. VOL 60 May 2010
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“Forced ventilation motors are used in many applications such as underground conveying where temperatures rise above the standard operating conditions,” explains Fanie while pointing out the various size motors in the workshop being fitted with exterior fan systems. “We design the forced cooling unit according to supplied specifications for each application and make everything for it in-house before painting
the complete unit to each customer’s specific requirements.”
Brakes
IGS supplies the Corbetta range of brakes from Italy to cover light duty through to heavy duty mining applications. “Generally choosing the correct brake or clutch in a mechanical drive is particularly important, because they are closely linked to the machine’s good performances and safety features,” says Fanie. “Brake units operate in various ways and the choice depends on the application. Mechanical brakes are for easy installations, smooth engagement of the machine and when manoeuvring efforts and response accuracy are not significant. “Electromagnetically-operated brake systems allow quick remote control, change in speed and programmed control while hydraulic brakes are used when large loads need to be controlled with reliability,” explains Fanie. “Pneumatically-operated brakes offer quick response times, high torque with simple and versatile control. Ultimately the choice of the type of brake to be used depends both on economic and technical factors.”
Friction discs
Fanie Kruger of Industrial Gearbox Services (IGS)
Power and torque transmitted by the braking unit, its dimensions, response times and the kind of assembly depends mainly on the material it’s made
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Forced ventilation motors in for a service
of and the number of friction discs in the brake unit. “As far as the number of discs is concerned, it must be noted that by increasing them, you not only have a smaller clutch outside diameter, but you also have a larger axial space requirement with longer response times and higher stokes of the control parts, especially when they are worn and consequently requiring frequent adjustments. “Apart from economic factors, it is important to point out that choosing a too small unit may lead to poor performances, the rapid wear of frictional parts and eventually to a loss of efficiency,” says Fanie about a common mistake often made in terms of brake systems. “If, conversely, a too large unit is chosen, you may face stiff movements of the component parts in the unit resulting in poor
sensitivity and an excessive increase in the inertia of rotating parts.
Proud stamp
“Whatever we repair we always put our nameplate on the job because we’re proud and assured in our workmanship,” says Fanie in conclusion. “One good thing that came out of the recession is that the
Just a thick grimy paste left behind in the sump
fly-by-night operators who had given the gearbox repair market a bad name, have been thinned out significantly. They used to approach us on a regular basis to do machining work on gearboxes, but lately the enquiries have dropped significantly.”
Fanie Kruger, IGS, Tel: (011) 452-7788, Email: sales@ igsa.co.za
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POWER GENERATION
Produced by: PROMECH PUBLISHING, P O Box 373, Pinegowrie, 2123 Republic of South Africa Tel: (011) 781-1401 Fax: (011) 781-1403 Email:
[email protected] Website: www.promech.co.za Managing Editor Susan Custers Editor Kowie Hamman Advertising Pauline Bouwer Circulation Catherine Macdiva DTP Zinobia Docrat/Sanette Lehanie Disclaimer PROMECH Publishing does not take responsibility for the opinions expressed by individuals. Printed by: Typo Colour Printing Tel: (011) 402-3468/9 A complete steam turbine plant in Brazil
Creative Co-Generation
the resources to meet the demand. The country will need the participation of IPPs. “Cogeneration is potentially a quick and effective response as there are many potential participants already in the economy,” he added. “By Eskom’s own estimation, about 900 MW can be generated from industrial cogeneration. The advantage of IPPs is that these plants are not on Eskom’s balance sheet. Further, IPPs share the risk in the transaction. When Eskom builds plants, all risk is passed through to the consumer and taxpayer. IPPs can also build and operate faster and more cost-effectively than Eskom.”
Copyright
All rights reserved. No editorial 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, 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.
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IPPs
The electricity shortage is on everybody’s lips and one solution is IPPs (Independent Power Producers). However, the concept of private producers is a complex subject that boils down to the cost per kilowatt hour to produce electricity, directly affecting the price that consumers will have to pay in the end for electricity.
t the current price of electricity, IPPs simply won’t be able to produce electricity cost-effectively as it still costs more per kilowatt hour to generate electricity in any form other than Eskom’s current power stations. Eskom, being the principle buyer of electricity from IPPs, will obviously not pay more for electricity from an outside supplier when they are generating it themselves for less, which is probably one of the main reasons that IPPs have not got off the ground in South Africa.
It is clear that Eskom, on its own, does not have the resources to meet the demand
Doug Kuni, managing director of the newlyformed South African Independent Power Producers Association (SAIPPA), recently stated in the press that South Africa needs IPPs and industrial co-generation as part of the solution to our generation capacity crisis. “Looking at the future supply-side requirements of the economy of South Africa, it is clear that Eskom, on its own, does not have
Technologies
In the rest of the world, IPPs are a reality where special equipment for co-generation and various types of independent generation methods with a variety of fuels has already gone through the development phase to bring a number of viable technologies to the market. “SA Mechanical Engineer” speaks to James Blakemore, the chairman of the Zest Group of companies which are now offering several of these proven technologies to the South African market. “We got more involved in power generation VOL 60 May 2010
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POWER GENERATION
Permanent generation
Zest’s range of power generating equipment was extended even further a year ago to include a full range of equipment for permanent power generation. “We established Zest Energy after acquiring shares in a company that has been providing power generating equipment into South Africa for many years,” explains James. “Principally this will give us an opening in the co-generation market for which there are huge opportunities in Africa, especially in the sugar industry that stretches as far up across the continent as Sudan.”
Other options
A TG320 steam turbine being inspected at a plant in Brazil
James adds, “Coenraad Vrey, managing director of Zest Energy, has also brought other technology to the table such as gas engine technology from Spain which utilises landfill gas, sewerage gas, process gas or natural gas as a fuel,” adds James. “Through WEG, whose electric motors we distribute, we have access to hydro power generation technology. They build hydro power generator stations ranging from 3 to 50 MW, which are small compared with the co-generation technology we bring in from Brazil. “Although South African terrain generally isn’t suitable for hydro power generation, there are opportunities to install this technology in other African countries.”
equipment after acquiring IMS in Cape Town,” James says. “Since the sixties they’ve specialised in generator sets for emergency use. We’ve always had alternators in our stable, but when IMS came up for sale about four years ago, we decided to buy 100% of the business. Since then the business has extended to building large gen-sets of up to 12 megawatt for hospitals, telephone companies and computer centres.
Co-generation
Move the whole generator set to where there is a shortage of power
Gen-sets
“Shopping centres, mining plants and factories want to secure their supply of electricity by having gen-sets installed to supplement the supply from the grid or when there is load shedding,” says James. “A 12 MW plant which we built for a mine, for example, consists of several generators of 1 to 1.5 MW each. These units are then synchronised to provide a single supplementary source of power that kicks in a couple seconds after a power failure occurs. Some shopping centres have rolled out such installations at all their centres across the country. “The latest we’ve built for standby power on a mine are four mobile trailer units, with each trailer unit generating 2.5 MW. With this type of solution, they can move the whole generator set to where there is a shortage of power and run the sets in a synchronised mode to complement the shortfall of electricity.”
Although the company is targeting the sugar cane industry with their co-generation equipment, the mining industry, where Zest has had huge success in terms of standby power generating equipment, is also seriously looking at all the alternative ways of generating supplementary power. “Although the gen-sets we provide are mini-power stations, it still is uneconomical to run a diesel generator to generate power on a permanent basis,” says James. “However, significant opportunity exists in the form of co-generation where extra power generated by a privately-owned power generating plant can be sold back into the grid by using an alternative fuel such as bagasse from sugar production or waste gas from landfills.. Although these technologies and economics can only be explored in full once IPPs are a reality in South Africa, there has been a keen interest from all industries in the products we are bringing in from Brazil.” “In Brazil, the sugar industry is self-sufficient and generates all of the power required to support its operations. The additional power is then sold to the utility, which contributes towards more than 4% (2GW) of the total power generation capacity of the country,” says Coenraad Vrey, managing director of Zest Energy. “All the steam driven mills and centrifuges on their sugar processing plants May 2010
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have been converted to more effective electrical drives, while the steam generation plants have been upgraded to the higher pressure needed for turbine power generation.
A TMC steam turbine rotor
Filling the gap
“South Africa is currently in the same position that Brazil found itself about nine years ago,” adds Coenraad. “Brazil was dependant on hydropower (91%), but severe droughts at the time caused a dramatic shortfall of energy and led to the development of alternative power generation systems. Now the average sugar processing plant easily generates between 25 to 50 MW and since these plants only use about 40% of this power, it presents an ideal opportunity for them to participate in the generation and distribution of power, thereby combating power shortages throughout the country.” The steam turbine units the Brazilian supplier, TGM, manufactures can generate up to 150 MW and for more power, units can easily be combined to increase the output.
Only have accessible bagasse for about eight months of the year
“Normally sugarcane estates only have accessible bagasse for about eight months of the year. To deliver constant power, we can now install dual boilers that can also run on coal for those short periods when no bagasse is available. In Brazil this translates to more than 97% power generation availability throughout the year, which is what we are now offering the local market.”
we need electricity to facilitate these efforts and achieve our future objectives.”
James Blakemore, Zest, Tel: (011) 723-6000, Email: james@ zest.co.za or Coenraad Vrey, Zest Energy, Tel: (011) 7236000, Email:
[email protected]
Gas engines
Equally viable are the gas engines Zest Energy is marketing. However, in South Africa this market is directly dependent on IPPs becoming a reality so that electricity can be sold back to the municipality or to the utility. “There are opportunities where we can look at sewerage gas as well as landfill gas, but the infrastructure for this is not there yet,” says Coenraad. “We have clients that have other alternative fuels to burn in engines like this, but it is still too expensive to implement the technology because power from Eskom is still cheaper. Even if Eskom’s price increases to meet the cost of running gas engines, you will still need an IPP through which to sell the power.” Despite all the hurdles, industries across Africa are seriously considering the various technologies Zest Energy is offering. “I cannot reveal the detail of the projects, but we are in various stages of negotiation for three different projects in Africa. The first project is for the sugar industry, the second is a gas project and the third is a supplementary power generation system,” says James. “The point is, the interest is there to bring the technology used across the globe to address the serious power problems we are facing in Africa. Essentially, Africa has plenty of natural resources waiting to be explored, but THE SOUTH AFRICAN MECHANICAL ENGINEER VOL 60 May 2010
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POWER GENERATION NEWS
Energy source of the future
Hatch principal power consultant Dieter Matzner says that there is still ample opportunity to transform South Africa’s energy supply from what it is today - at 95% coal-fired power supply - to 80% renewable power supply in the next 40 to 50 years. Dieter notes that the African continent has an abundance of solar energy, hydropower and to a lesser extent wind power. Currently only 7% of the potential of hydropower in Africa is being developed. At least another 230 000 MW of power supply can be economically extracted from the current river systems. As far as solar power is concerned ‘the sky is the limit’ and power supply capacity is essentially determined by governments’ political will to include it in the energy mix. “I believe there is no reason why South Africa cannot achieve the renewable energy status of the international world. If South Africa were to follow international trends, we should in the next ten years, have the capacity to supply up to between 15% and 20% of our current power supply
Included in Ai-Tec’s range of industrial and commercial equipment, are robust, low noise generators, available from 2 kVA to 2 500 kVA - suitable for industrial, commercial and domestic applications
Special acoustics
Included in Ai-Tec’s range of industrial and commercial equipment, are low noise generators, available from 2 kVA to 2 500 kVA - suitable for industrial, commercial and domestic applications. “What sets these generator sets aside in a highly competitive market is the specially-designed acoustic enclosure that significantly reduces noise levels,” says Arnold Retief, director, Ai-Tec. “This robust enclosure, which contains the generator unit, is able to withstand operation in harsh outdoor environments, including the mining, marine and chemical sectors. “The need for dependable standby power to enable continued business in the event of a power outage means standby generators have become a necessity - particularly for those industries that rely on electricity to survive. An emergency power supply is also essential for maintaining safety and security standards.” The acoustic design of Ai-Tec’s generators meets the requirements of EU legislation 2000/14/EC. This is achieved by the extensive use of a rock wool and perforated zintec steel lining, enhanced by the efficient management of cooling air. The exhaust noise is minimised by a silencer which is mounted within the base frame. Also integrated within the base frame are the filler, gauge and accessory points. The fuel tank allows eight hours running of the generator, at 75% load.
Arnold Retief, Advanced Industrial Technology (Ai-Tec), Tel: (032) 552-2658, Web: www.ai-tec.co.za
with renewable energies,” explains Dieter. He foresees that solar power in South Africa in the next 10 15 years, will achieve grid parity. This means that the cost of supply will become competitive to clean coal carbon capture and sequestration technology implemented and even nu- Dieter Matzner clear power. “I believe that the real cost of power generated in the South African grid by 2020 in today’s value is going to be about R1,50 per kWh. This will be comparative with solar power and wind power in the next 10 - 15 years,” he adds.
Website: www.hatch.ca
Contact Pauline Bouwer on Tel: (011) 781-1401, Fax: (011) 781-1403 or Email:
[email protected] with all your advertising bookings
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POWER GENERATION NEWS
Laser cladding perfected
Researchers at the CSIR (Council for Scientific and Industrial Research) have demonstrated a world-first laser cladding system that offers a permanent solution to sealing leaks and repairing cracks at power stations. The patented laser beam-welding and leak-sealing technology, which was developed for Eskom in collaboration with Eskom welding engineers, will aid in the maintenance of South Africa’s power stations, particularly in the sealing and repair of leaking water coolers in situ. During the demonstration to Eskom and other external stakeholders, the CSIR National Laser Centre head, Dr Ndumiso Cingo, says, “This is a worldfirst technology designed and developed in South Africa by South Africans.” The impact of this development will be fully appreciated only much later, he says. “The technology breakthrough coincides with the 50th anniversary of the laser. The design and development of this technology has proved that
the application of lasers extends much further than could have been foreseen when they were first demonstrated a few decades ago,” he adds. “The application of lasers also extends to all aspects of modern manufacturing, especially in the technology of refurbishment and maintenance.” The state-of-the art laser welding and cladding system is mobile and able to reach multi-storey heights with the laser power unit located firmly on the ground. The system functions by remote control provided by an operator on the ground. “We have designed a system that is completely mobile and can execute maintenance and repairs on site,” says NLC operations manager, Hardus Greyling. Laser cladding is a remarkably accurate and an effective process whereby weld overlays of layers as thin as 0,1 mm can be applied, with minimal distortion to original components. This is specifically valuable when performing maintenance welding on components.
Mzimasi Gcukumana, Research Communications: National Laser Centre, Tel: (012) 841-2535
Industry; a tough business that can only succeed when the suppliers it chooses and the equipment it specifies meet the challenge. ZEST; more than just products. More than MV and LV motors, matched drives, diesel generators up to 2000kVA, transformers up to 200 MVA, switchgear, vacuum ring main units, static and portable MCCs solutions and cable. ZEST is the partner Africa’s industries need.
A partner able to play a significant role in every project or expansion. A partner capable of delivering dependable support for both original equipment manufacturers (OEMs) and end users. A partner that backs hundreds of man years’ experience with an intense commitment to stock, a comprehensive network of branches, agents and professional projects management.
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Johannesburg (011) 723 6000 • Cape Town (021) 551 2710 • Durban (031) 569 7260 Port Elizabeth (041) 486 1262/1396 • Middelburg (013) 246 2849 • Rustenburg (014) 594 0450 Richards Bay (035) 751 1607 • Trichardt (017) 638 1571 • Pomona (011) 723 6000 www.zest.co.za
Peripheral 2010108
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NUCLEAR INSTITUTE (SA BRANCH)
A Sense of Unreality
A further item of essential reading in the great IRP2 energy debate has appeared in the form of ‘Generating the Future’, a report by the UK Royal Academy of Engineering. The UK’s Climate Change Act of 2008 commits to reducing greenhouse gas emissions by no less than ‘at least 80%’ of 1990 emissions by 2050. The Academy report presents four scenarios and considers how this might be achieved in each scenario – at least in the case of carbon dioxide.
T
he first and least demanding scenario assumes zero increase in total energy demand between now and 2050. The fourth is based on an overall reduction of some 46% in total energy demand. Because it’s hard to imagine a developing country targeting zero load growth, let alone load diminution, the following has to do only with the first scenario.
John Walmsley
The contention that biomass can provide 45 GW(av) (contributing to transport, electricity generation and the provision of low grade heat) is surprising. According to J C MacKay’s ‘Sustainable energy – without the hot air’ discussed in February’s issue, 45 GW(av) would use up of the order of 10 000 km2 of arable land. In the supply side analysis, nuclear generation and fossil-fired plant equipped with carbon capture and storage are lumped together to provide 77 GW(av) of base-load energy. I wish CCS researchers every success but personally find it hard to believe, for example, that tens of millions of tons of CO2 per year per power station can be captured and hidden under the North Sea for ever. If CCS does not work, the 77GW(av) will all have to come from about sixty new Generation III+ reactors. Since the feasibility of CCS will take years to establish the Brits (opposed by the Scots) are preparing to build nukes now, as we must for the same reason. The report suggests an answer to a question that continues to bother me about wind energy. A few percent of wind energy can clearly be ‘hidden’ in the system. When the wind drops simply run other plant a little harder. Woolly economic thinking perhaps but feasible. But when does intermittent energy really start to become a nuisance on the grid, and what is the maximum? Figure 5 of the report shows a maximum credible 33 GW(av) of ‘intermittent renewables’, very largely wind, feeding into the 127 GW(av) grid. The answer therefore appears to be around 25%.
Currently, the UK total average power supply is evidently 207,5 GW(average) of which a mere 20% is electrical. In 2050, with the same total energy demand, the predicted electrical energy contribution has risen to a startling 66%. The increase is driven largely by a switch from fossil fuels to heat pumps for low grade heat and to electricity for transportation. To repeat, the Academy concludes that, if the total energy demand remains constant, the nation’s electrical energy generation must at least triple if the 80% target is to be met. Hence the title of this article.
I wish CCS researchers every success but personally find it hard to believe
The report is concerned almost entirely with what must happen if imposed scenario requirement are to be met, rather than what is technically and economically feasible. It does suggest, however, that the necessary strengthening of the transmission and distribution systems would alone cost many billions of pounds.
Too immature
Weather forecasting
One of the requirements is to maximise the use of renewables. The renewables contribution is therefore the same for all four scenarios, being the ‘highest levels that could realistically be delivered by 2050’. Their total predicted average power contribution (omitting biomass) is 33,2 GW(av). The major contributors are on-shore wind 6,5 GW(av) (from 24 GW installed - implying a generous 27% capacity factor), off-shore wind 11,4 GW(av) (from 38 GW installed), and solar PV 7,2 GW(av) (from 72 GW installed). Biomass contributes 45 GW(av) thermal. Grievously, concentrated solar power with energy storage punted in the free NIASA video ‘Energy Security – the Nuclear Contribution’(1) is considered too immature a technology for inclusion in the analysis.
As well as much more muscular, the national grid will have to become ‘smart’ to deal with instability and to incorporate weather forecasting and demand-side management. The ‘smart’ grid is described as a ‘hugely complex issue … currently being investigated’. The report stresses the enormity of the engineering effort required. The only parallel is the 1940s wartime effort. Which brings to mind another thought. What if the sceptics are right and global warming has nothing to do with CO2? How amazing would that be?
John Walmsley To obtain a free copy of the NIASA video ‘Energy Security - the Nuclear Contribution’Email:
[email protected] specifying ‘summary disc’ and a postal address
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FILTERS & FILTRATION
Half Price is Half Performance
Allen Cockfield, managing director of Artic Driers
Many maintenance engineers are under pressure to cut costs, so they buy generic replacement filter elements at half the price of the original. Yet they’re surprised when they only get half the life out of these look-alike cartridges. The look-alike elements are often well made, externally appearing to be one and the same as the original, just in a different colour, but on the inside it’s a different story altogether.
“Some look-alike filter elements are designed to price level, often substantially deviating from the original design to achieve this objective,” he says. “Low-cost elements have a shorter life because they simply don’t have the same filtration area in the form of pleated media inside the element.”
Air filters
T
o make matters worse the look-alike elements are regularly palmed off as the original and sold at the same price, giving the seller a fat margin for something that simply isn’t as effective as the original. “SA Mechanical Engineer” speaks to Allen Cockfield, managing director of Artic Driers about this phenomenon plaguing the South African market.
Tends to blind over faster than a pleated element
The coalescing and particle compressed air filters in question are manufactured by OEMs to exacting standards and casings are fitted with high capacity filter elements that use pleated filter media to provide large filtration surface areas with low pressure drops. “Pleating of the multiple layered filtration media provides a high surface area that is 300 to 400% greater than any ordinary spiral wound cartridge,” explains Allen. “This provides low operational pressure drops using less power while service intervals are longer, leading to lower operating costs.
The real thing on the left, with the look-alike filter element on the right
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“The look-alike spiral wound element has a smaller surface area and tends to blind over faster than a pleated element,” adds Allen. “This also leads to higher differential pressures and subsequent energy wastage. Another point to be considered is the filtration efficiency. Rarely, if ever, do look-alike suppliers provide data sheets for the elements they sell and the question is, are you getting the same performance?”
Pointing out differences between effective filtration and low-cost filtration is certainly not a personal vendetta
The real thing
For twelve years Artic Driers has been the distributor for the BEA Technologies range of filters made in Italy. To explain the in’s and out’s of the genuine article, Allen describes some of the salient features. “Manufactured in die cast aluminium or as a fabricated casing, we have a range of flow capacities from 15 to 33 000 cubic metres per hour. All casings are fitted with high capacity filter elements that use pleated filter media to provide large filtration surface areas with low pressure drops,” he says.
The JDM level-controlled drain
“The filtration media is sandwiched between an inner and outer layer of perforated stainless steel
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that guarantees element and dirt-holding integrity under all standard operational conditions. The elements are available in four colour-coded filter grades from 10 to 0.01 micron with an activated carbon element that provides oil removal down to 0.003 ppm.
and pipe scale with zero chance of a malfunction,” explains Allen. “Electronically-controlled level drains eliminate expensive compressed air from escaping by only draining when the bowl is full of waste condensate.”
Not a vendetta
“For over a decade Bea Technology has not changed the element system and still markets the same screwed filter casing design that has been in use for more than 12 years,” says Allen. “The original VIP casing design with many practical features has been imitated by many and still represents a brilliant design standard in the compressed air industry. “Pointing out the differences between effective filtration and low-cost filtration is certainly not a personal vendetta, there are other original equipment suppliers who are also affected by the flood of ‘cheap’ filtration elements,” says Allen. “We’re trying to help people save money, not only in running costs, but also in terms of energy consumption.”
Drain valve is signalled to close before expensive compressed air is wasted to atmosphere
The electronic capacitive level sensor monitors the level of condensate in the bowl and signals a 12 volt heavy duty drain valve to open when the upper limit is reached. Once in the open cycle, the level of condensate drops and the capacitive level sensor keeps the drain valve open until a lower level is reached. At this point, the drain valve is signalled to close before expensive compressed air is wasted to atmosphere. The JDM units are available for pressure from 3 bar to 50 bar working pressures
Payback
Energy saving
With the rising cost of energy in mind, Artic Driers is now also offering a new product to the South African market that helps to save precious compressed air. “Compressed air is already expensive but, with power costs rising, the cost of compressed air is bound to double in future,” says Allen. “The use of intelligent level controlled drains on air filtration systems is an effective way of reducing compressed air wastage and power costs. We now have a range of JDM level-controlled drains, built for the harsh realities of industry where a lot of air goes to waste with traditional timer-controlled drains.”
Just like the filter elements, the drains do cost a bit more initially, but the payback time is dramatically shortened just from the energy saved by the system. “Initial purchase price should not be the sole criteria,” says Allen in conclusion. “In fact, low cost is often a precursor to a long term supply problem. Filtration equipment should only be sourced from suppliers who are able to consistently back up the supply chain and have a long established track record in the compressed air industry. “Many suppliers, with these pre-requisites, will also offer compressed air quality audits for dew point, oil carry over, air flow and pressure to ensure long term air quality performance and client satisfaction.”
Allen Cockfield, Artic Driers, Tel: (011) 425-3484, Email:
[email protected]
The system
“In this system, the air enters the coated aluminium bowl via a full length internal screen to ensure the valve can tolerate the ingress of heavy solids
The range of drains
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SEW-EURODRIVE - Driving the world
We don’t develop products we develop solutions.
Suppliers of geared motors, industrial gears, frequency inverters, drive electronics, servo technology and services.
Naturally, as the leading drive-technology specialists, we consistently develop new products that are above all reliable, energy-efficient and produced cost-efficiently. Moreover, our know-how and experience allows us to go a step further than the rest – providing solutions that you can build on. That’s what we call Drive 360o – Seeing the big picture: from the system availability to problem-solving competence, achieving lower operating costs through energy-efficiency right through to finished systems. We can fulfill all your needs.
SEW-Eurodrive (Pty) Ltd PO Box 90004 l Bertsham 2013 Tel: +2711 248-7000 Fax: +27 11 248-7289
0 THE www.sew.co.za SOUTH AFRICAN MECHANICAL ENGINEER
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FILTERS & FILTRATION
Every Drop Counts
It takes only one litre of oil to render a million litres of water contaminated beyond human and, in many cases, even industrial use. As South Africa is a water-scarce country, it’s crucial for industry to pay special attention to the spillage of waste oils.
E
lectricity was first, it’s now expected that water will become more expensive in future. It’s also important to preserve the environmental integrity of this precious commodity. Although many industries are aware of the laws against spilling waste oil, their facilities aren’t always sufficient to effectively remove oil from waste water so they buy more processed water instead of re-using the water they have.
even a backwash does not remove the oil particles once they’re impregnated on the membrane,” adds Jacques. “The RO system at one of our client’s premises is used to reclaim waste water from all over the plant, but a lot of this waste comes from the vehicle washbays and the workshops where gearboxes are overhauled and serviced.”
Buy more processed water instead of re-using the water they have
A company that specialises in filtration technologies to remove oil from waste water is Procon Environmental Technologies in Witbank and Pretoria. To learn more about the benefits of these systems, “SA Mechanical Engineer” speaks to Jacques Steyn, the company’s environmental engineer. “Prevention is better than cure, it is much better to avoid pollution at the source rather than trying to fix it later on.
Slightest bit of oil
“Accidents do happen, so we have solutions to clean up the mess and help prevent the accident from happening again. In addition we have technologies that have been proven to save companies money, not only in terms of re-using waste water, but also to extend the life of water purifying systems further down the line,” says Jacques. “A good example is installing our Mycelx filtration system prior to a reverse osmosis system, purely to extend the life of the very expensive membranes in the RO plant. “The slightest bit of oil on the membranes of an RO system renders the membrane useless because
Jacques Steyn, Procon’s environmental engineer
The system
All this waste water drains to sumps from where it goes through the purifying system. “At the sumps we installed our Ultraspin hydro-cyclone systems to remove the core large particles of oil from the water,” says Jacques. “The water coming out of this system still contains small oil particles of about 10 parts to a million and these are then removed by the Mycelx filtration system before it goes to the RO system.” VOL 60 May 2010
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FILTERS & FILTRATION
The Mycelx filtration system
Fraction of the cost
The filters are only replaced every four to six months at a fraction of what is used to cost the plant to replace the membranes of the RO system on a regular basis. “To ensure minimum downtime to replace filters, we designed a dual filtration system,” says Jacques.
three-phase process that gets rid of diesel which is water-soluble and can’t be removed by the hydro cyclone or the filtration system which is installed in varying degrees depending on the level of contamination. “This ‘Star-Track’ design is a complete containment system with a comprehensive arrangement of drains that captures and directs the oil spillages to our treatment system.”
We are literally saving the plant millions in terms of lifecycle costs
“In parallel to the in-duty filtration system, we have a complete standby system so that the client simply switches to standby filtration while filters are being replaced on the duty system. On this 70 cubic metre per hour filtration system, we are literally saving the plant millions in terms of lifecycle costs as our system costs comes in at around 10% of their previous running costs.”
Growing awareness
Remote locations
A similar waste water solution was designed for the Transnet railway service depots. “These depots are usually remotely located where there isn’t any access to the usual process water disposal through a sewerage network,” explains Jacques. “The law requires that waste water discharged into the environment should contain less than 2.5 milligram solids per litre and this in itself is a problem for these depots where the grease, diesel and oil spill from rail cars and locomotives being serviced, severely contaminates all the waste water. “We are so confident in our solution that we offer a money-back guarantee should the discharge water from our system contain more than 2.5 milligram per litre,” says Jacques. “Our solution includes special treatment for diesel contamination. It’s a
Procon is the sole distributor of this technology in Africa and has engineered many solutions ranging across all industries, from large mining plants to railways yards, vehicle washbays, refineries and many other industries where oil is used. “In our experience there seems to be a growing awareness in industry for the need to protect the environment by considering sustainable solutions to oil pollution,” says Jacques. “South Africa has had comprehensive environmental legislation in place for many years, but enforcing it has always been a problem because the department doesn’t have enough teeth to go after the culprits. “Having said that, over the last couple of years some people have been sent to prison for oil and chemical pollution offences,” says Jacques in conclusion. “The amalgamation of the departments of water affairs and environmental affairs has proven to be a good move as law enforcement will now be co-ordinated much more effectively. On a daily basis, we now receiving enquiries, and many of those who have merely made enquiries in the past, are calling us to order the equipment.”
Jacques Steyn, Procon Environmental Technologies, Tel: (086) 6666-33, Email:
[email protected]
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STEAM, TURBINES & BOILERS
Saving on Process Energy and Steam
The concept of outsourcing a process energy or steam generating plant to an entity that specialises in running and maintaining process energy and steam generating systems has been alive and well for over a decade. The creation of a whole new market known as Contract Energy Management or CEM has since been embraced by various industries including the food, textile, metal, paper, timber, chemical and para-statal sectors.
Dennis Williams
lthough CEM is well-established and widely used in Europe, Britain and America, it is a fairly new concept to the South African market, instituted by Associated Energy Services (AES) in the early nineties and today steadily growing into general practice. “SA Mechanical Engineer” speaks to marketing director of AES in Cape Town, Dennis Williams.
A
AES has proven expertise in biomass based steam and electricity generation
staffing, operations and efficiency, maintenance, environmental and occupational health and safety management processes. Through the application of these processes, we are able to provide value where energy plant operation and management skill sets are lacking.” Essentially the benefits and identified savings to the client are embodied within the energy supply charges and efficiency of operation, where the client buys useful energy from the CEM company in the form and quantity required. The focussed application of professional plant operation and maintenance procedures provides operational benefits such as improved reliability and availability, improved efficiency, reduced environmental risk and extended plant life for the client.
Proven over and over that these resources cannot be cost-effectively managed by individual companies
“The formation of a stand alone company enabled AES to become the local market leader in combustion-based CEM following its initial pioneering work done on outsourced energy plant operation,” Dennis explains. “We operate and manage a variety of energy installations and generate steam, thermal oil, hot air/gas and electricity for supply to clients.
How Does CEM Work?
CEM concept
“We’ve developed in-house management systems covering the key areas of energy plant operation,” he adds. “These include technical review,
“We are able to offer CEM services to either existing energy plant operations, or alternatively to fund and install new Greenfield energy plant installations under a CEM contract,” elaborates Dennis. “We assume full responsibility for staffing, management, maintenance and control of the energy plant on behalf of the client and charge the client on the basis of a fixed monthly charge together with a per unit energy charge applied to the monthly energy consumption. “For example, purchasing steam will be charged in VOL 60 May 2010
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STEAM, TURBINES & BOILERS
ment personnel across a number of energy operations. It has been proven over and over that these resources cannot be cost-effectively managed by individual companies that simply use energy/steam as a utility to their core business.”
Sawmilling operation
As a practical example, Dennis sketches a case study. “In 2004, AES began negotiations with the operator of a sawmill in the Eastern Cape for the full outsourcing of the entire power station operations at the site,” he says. “The site required substantial technical skills and operations input to enable the selection of updated control system technologies, as well as the design and implementation of furnace and fuel feed system adjustments.
The use of sawmill residue as fuel ensures that the timber resources of the client are utilised in an optimal and sustainable manner
R/tonne of steam and electricity in c/kWh,” explains Dennis. “The monthly consumption of energy is measured by appropriate logging instrumentation and the client is billed for the energy usage. All costs associated with energy generation are borne by AES.
197731 Poweroil 130x210.pdf
“We secured a five-year contract to manage the entire power generation station at the site covering generation and supply of high pressure superheated and low pressure saturated steam,” he elaborates. “This included the generation of electricity for use on the site via steam turbine generators.”
The operation
“Our business 4:26:22 PM model enables the leveraging of high 9/23/08 level, high value energy engineering and manage-
The site plant includes a steam de-superheating station and a combination of fully- condensing and pass-out turbines which enables AES to balance the site steam requirements based on demand for low pressure process steam and high pressure
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superheated steam for power generation. AES has been responsible for implementing various changes related to boiler and furnace control systems, fuel sizing and pre-screening and refractory installation, design and maintenance on the existing boilers. The company has also been responsible for project managing the installation of an additional low pressure boiler and step grate furnace to generate additional low pressure steam, while making the current high pressure, superheated steam generation capacity available for additional power generation.
has been increased focus on renewable energy and its expanded use to enable the reduction of South Africa’s reliance on fossil based energy. The operation I’ve just described is an example of how industry can further these clean energy ideals.
With the shortage of engineering skills in South Africa, the CEM concept has become a solution to a critical problem
Skills
“Today, with the shortage of engineering skills in South Africa, the CEM concept has become a solution to a critical problem,” says Dennis in conclusion. Companies are finding it difficult to maintain production at previous levels due to the lack of energy management expertise for the operation of utilities and the training of the utility operating personnel, such as boiler house staff. AES employ more than 150 staff including skilled operations staff and 11 engineers. “Companies should be focussing their efforts on processes directly related to the production of their core business while the boiler house receives the management and financial attention of professionals in order to ensure an efficient operation.”
Dennis Williams, AES, Tel: (021) 532-3381, Email:
[email protected], Website: www.aes-africa.com
Renewable energy
“In addition, we worked closely with this client on the site to review the generation of steam and electricity in light of the client’s participation in the Eskom Pilot National Cogeneration Programme (PNCP),” says Dennis. “At the time AES was a registered participant in the PNCP and the later Medium Term Power Purchase Programme (MTPPP) and as such, provided input with regard to future plant operation, availability and cost assessments. “Opportunities related to the generation of carbon credits in terms of the United Nations Framework Convention on Climate Change (UNFCCC) for the site operations were reviewed and we were able to offer support in terms of reviews of the site registration process,” says Dennis. “Recently there
THE SOUTH AFRICAN MECHANICAL ENGINEER
VOL 60
May 2010
Are You Doing Your Bit? Green Supply Chain Awards
This prestigious award recognises people, projects and products that have gone above and beyond the call of duty to enhance the environment in which they operate.
The inaugural awards in 2009 enjoyed a wonderful response from the supply chain community and everything is on track to make this year’s event one of the industry’s most prestigious accolades.
Come and see who walks away with the coveted trophies and enter your product or project for this year’s event.
Entries for this year’s event close in June and the awards ceremony is being planned for 26 August 2010.
Contact: Catherine Larkin on Tel: (011) 789-7327/787-9127, Cell: 083 300 0331, Fax: (011) 787-7865 Email:
[email protected]
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Supply Chain AFRICAN MECHANICAL ENGINEER THE SOUTH Today Jan 2010
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cope smoothly under these very grueling conditions. Mining operations can proceed smoothly without any concern about unplanned down time caused by premature electric motor failure,” concludes Tony.
Jane Goldwyer, CMG Electric Motors, Tel: (011) 453-1930, Fax: (011) 453-9560, Email: jane.goldwyer@cmggroup. co.za, Website: www.cmggroup.co.za
Substantial savings
A leading Middelburg-based coal operator has recorded significant savings on capital expenditure, repair and downtime over a relatively short period, following the installation of CMG PPA electric motors. The mine is currently operating approximately 50 CMG Premium Efficiency PPA electric motors and the reliable performance of these rugged units has lead to the mine standardising on the PPAs and the replacement of all existing motors with these high efficiency motors is in progress. Branch Manager, Tony Campbell, says that CMG’s class “H”, IP66, TEFC (Totally Enclosed Fan Cooled) PPA motors are supplied with standard features to meet all customer specifications. He adds that numerous CMG PPA motors are successfully operating at seven of the group’s coal mining projects. “Electric motors are one of the most important components to any production line and the customer found that a tremendous amount of time and money was being expended on repairing and replacing old faulty motors,” states Tony. Tony discusses the application of the electric motors and says that the motors are used to feed pumps in the mine’s basement, an extremely harsh location due to water and spillages. “As a result, motors simply did not last and had to be replaced every three to four months, a very high cost exercise. However, after replacing the existing motors with our PPA electric motors over two years ago, the customer has not lost a single motor since installation, despite the necessary regular wash down and motor start up which can be as frequent as ten times per every nine hour shift. “The customer reports that CMG motors far outclass other electric motors currently available to local industry as they
SKF has developed a wide range of bearing housings to ensure the right solution for virtually any application. Some of the latest housings designs available from SKF to assist with improved reliability and reduced costs include SNL plummer block housings, SONL plummer block housings and FNL flanged housings. SNL plummer (pillow) block housings are SKF’s most popular housings. Because of their versatility it is seldom necessary to resort to tailored housings for specific applications, minimising costs and production downtime. Warren Walker, SKF Engineering Manager, says that the housings are horizontally split and have two or four attachment bolt holes in the base as standard. The basis of the SNL plummer block housing system consists of a number of housings of the same design but in different sizes. Walker explains that by combining these housings with different standard seals, a wide variety of housing variants can be supplied, all belonging to the standard range. SNL plummer blocks (up to size 32) can accommodate shaft diameters ranging from 20 to 160 mm making them a flexible solution. SKF’s SONL plummer block housings, which replace the former SOFN housings, are intended for oil lubrication and are designed for bearings operating at high speeds and at high temperatures. Primary applications include fans, flywheels and emergency power installations. FNL flanged housings are manufactured by SKF in two designs depending on size. Smaller sizes up to and including size 13 have a triangular flange; larger sizes have a square flange. The housings are equipped with double-lip seals. FNL housings are equipped with two drilled and tapped holes for relubrication as standard. The SNL grease guiding system is also used in FNL housings and Walker explains that this feature guides the grease VOL 60 May 2010
The housing issue
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Market Forum
into the bearing when lubricating self-aligning ball bearings or CARB toroidal roller bearings. To simplify mounting and make alignment more accurate, centre lines to indicate the housing bore axis and vertical axis are cast into the housing flange. As a variant, the FNL housing can be supplied with a machined recess that can be used to centre the housing on an appropriate spigot on the machine wall. As such, Walker points out that the attachment bolts are not subjected to shear forces. The spigot can be provided by machining the wall accordingly, or attaching an appropriate guide ring to the wall.
Joubert – MarComm Assistant - SKF SA, SKF South Africa (Pty) Ltd, Tel: (011) 821-3500, Fax: (011) 821-3501, Email:
[email protected], Website: www.skf.co.za
Many different capacities
The SKF range og bearing housings
The Case range of wheel loaders includes many units with different capacities, but three high performance models – the 621E, 821E and 921E series – are available in Southern Africa from CSE
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The Case range of wheel loaders includes many units with different capacities, but three high performance models – the 621E, 821E and 921E series – are available in Southern Africa from CSE Equipment Company
Equipment Company. The largest Case wheel loader obtainable locally is the 921E machine, with enhanced power for efficient operation in arduous applications in construction, quarrying, mining and related industries. “This robust wheel loader has a maximum operating weight of 22 962 kg, an engine rating of 221 kW and bucket capacity of up to 4,60m³,” says Rod Watson divisional director of CSE Equipment’s construction division. “The 921E series is powered by an electronically controlled Tier III engine, with an 11 litre capacity. This machine has multiple power curves – economy, standard and maximum – that provide the correct power rating for each specific task, like loading and digging, with low fuel consumption for lighter stockpiling duties. “The auto working mode automatically adjusts the engine power to meet the exact needs in diverse operating conditions, enabling the wheel loader to move the maximum amount of material per litre of fuel. Electronic fuel injection, with high injection pressures, allows cleaner, more efficient burning for increased output, efficient fuel consumption and an overall reduction in emissions.”
Rod Watson, CSE Equipment Company, Tel: (011) 922-2000, Fax : (011) 922-2108, Email:
[email protected], Website: www. cse.co.za
New prison boiler
Mpumalanga 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
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
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in the kitchen and to supply hot water to the ablution and laundry facilities at the prison,” says Nkosinathi Nkwanyana, 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
of tar from as high as 1000 mg/l down to 50 mg/l in the coal water stream. In doing so there is an overall reduction in contamination being fed to the hydrogen sulphide scrubbers and downstream heat exchangers, which will lead to increased efficiency of these systems. The reduction in contaminants will also significantly reduce the number of maintenance intervals currently required on the distillation columns, thus reducing the water consumption and downtime required for cleaning the distillation columns. VWS Envig will be designing, manufacturing, constructing and commissioning the plant. The project is currently in procurement phase, with commissioning expected in the third quarter of 2010.
Stuart Lawry, Project Engineer, VWS Envig (Pty) Ltd., Tel: 011 663 3600, Fax: 011 608 4772, Email:
[email protected]
Tender awarded
VWS Envig has announced the award of a tender to supply ArcelorMittal South Africa Newcastle Works with a tar removal filtration plant. The plant will be the first of its kind in South Africa. The filters are designed to reduce the concentration Stuart Lawry
Certainty that everything is running smoothly. That‘s what moves us.
ai_allg_13.0.1_en aik
Hairmann Hayak, Regional Service Manager, Voith Turbo Singapore
The efficient conversion of primary energy into mecha nical power – this is the world of Voith Turbo Industry. We are your reliable partner when it comes to systems competence, quality and innovative products. From variablespeed drives and control components in the power generating and the petrochemical industry, startup components in materials handling in the min ing industry, to cardan shafts and connecting coup lings for steel and the mechanical engineering indus try, to highly flexible couplings and hydraulic systems in construction, toolmaking and marine industry. As
one of the largest manufacturers worldwide of indus trial drives, we have the right solution for any task. Hydrodynamic, mechanical, electronic or hydrostatic: power transmission systems from Voith Turbo are efficient, save energy and reduce emissions – reliably and safely all over the world. Voith Turbo (Pty) Ltd. Tel. +27 11 418 4000
[email protected]
www.rsa.voithturbo.com
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The onboard filter which is standard on all units is used for the efficient filling and emptying of fluid. Different size flat face, quick connect couplings prevent particle ingress and ensure the correct oil is pumped into the appropriate machine. Electrically operated pumps are an option to standard hand pumps. Robust rubber wheels ensure easy mobility over rough surfaces. Specially designed carbon steel wheels are available for underground mining applications. These trolleys, which are manufactured using 97% local components, are equipped with carefully selected filtration systems suitable for most fluids.
Anton van Deventer, BMG Filtration, Bearing Man Group, Tel: (011) 620-1500, Fax2Email: 086-5322177, Email:
[email protected], Website: www.bmgworld.net
Paul Combe, new GM of Goscor Compressed Air Systems
Compressed air company re-organisation
In line with the group’s strategy of maintaining highly focused business units, leading equipment supplier, Goscor, has spun off its compressed air business into a separate business unit. Formerly part of Goscor Power Products (GPP), the new division, which includes the Sullair range of products, will be known as Goscor Compressed Air Systems (GCAS). New GCAS GM, Paul Combe says: “Everyone is under pressure to be as efficient as possible and in Sullair we have a significant competitive advantage in this regard.”
Goscor Compressed Air Systems, Paul Combe, Tel: (011) 230.2600, Fax: (011) 976.4807, E.Mail: pcombe@goscor. co.za, Website: www.goscor.co.za
Robust transfer trolley
BMG’s specialist filtration division has launched a new robust transfer trolley which transfers oil safely from the oil store to the plant, without the lubricator having to touch the fluid. “This efficient transfer system, which is convenient for users in diverse industries, including the mining sector, ensures safe and clean transfer and filtration of lubricating fluids up to 680 cST,” says Anton van Deventer, product manager, BMG Filtration, part of the Bearing Man Group. “This system has an easy to operate colour coded facility that virtually eliminates BMG’s specialist filtration division has launched a new robust transfer oil cross contamination.” For optimum cleanliness, the fluid is filtered twice. lubricator having to touch the fluid.
trolley which transfers oil safely from the oil store to the plant, without the
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company will also provide Xstrata with a maintenance and pump replacement service on all pumps. “We supplied all the vertical spindle pumps as well as horizontal pumps from the 75 DMP through to Warman 14/12 F AH pumps, and this was done over a five month period to dovetail with the project requirements,” Nico Smit, branch manager Weir Minerals Africa Witbank, says. All pumps are equipped with the Warman E-Base (Efficiency Base) system. “This is the first time that the E-Base has been installed on vertical spindle pumps and essentially means that by eliminating slippage on the v-belts, significant savings in energy consumption will be achieved. In addition, it will shorten the changeout on v-belts as it is not necessary to realign the motor with the pump,” Smit says. Smit says it is an innovative world first approach to pump v-belt drives, which ensures the correct belt tension, as specified by belt manufacturers, is applied throughout the life of
Weir Minerals Africa is committed to maintaining plant uptime
Innovative world first
Not only will the supply of 52 pumps by Weir Minerals Africa to Xstrata’s Goedgevonden plant in Ogies be the largest slurry pump installation in the Mpumalanga coalfields area, but the
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the system. “Correct tensioning on the v-belt is maintained without the need for constant and continual adjustment.” “This is achieved through the use of a simple, highly effective self-tensioning device known as the OST torsioning element,” Nico says. It consists of four precision moulded rubber mounts which store energy that is released as the belts stretch and wear.
Rene Calitz, Weir Minerals Africa (Pty) Ltd, Tel: ( 011) 929-2622, Website: www.weirminerals.com
is required and operating costs are reduced making these submersible pumps a very attractive alternative to vertical spindle sump pumps,” Klint concludes.
Lanelle Wheeler, Itt Water & Wastewater, Tel: (011) 966-9300, Website: www.flygt.co.za
Little attention
Slurry handling is considered one of the most demanding applications for any pump, and one of the costliest in terms of wear and tear, maintenance and downtime. Finding a solution to this problem will result in increasing efficiencies and productivity as well as an exponential reduction in costs. According to Klint Bawden, dewatering applications engineer at ITT Water & Wastewater, there is a market trend away from vertical spindle sump pumps towards submersible slurry pumps. “This is because these pumps are more user-friendly, require less infrastructure, are quiet in operation and more efficient when compared with vertical spindle pumps.” He points out that because the submersible pump operates directly in the slurry it requires no support structure and occupies less space. In addition, the motor and volute is an integrated unit, making it compact and easy to install. Another advantage because it operates underwater is the reduced noise level and, in some instances, silent operation is guaranteed. “Add to this, the Victaulic flange and coupling on the Flygt 5100/5150 Series pumps allows fast, easy connection to a wide range of commonly available fittings.” “Once installed, the Flygt submersible slurry pumps require little attention. Since there are no long or exposed links between the motor and the volute, less maintenance
A new level in design
Jetmaster (Pty) Ltd. exports products to Australia, New Zealand, UK and other countries. Their unique gas barbecues are optimised to suit the traditional South African style. The product has to be on a new level in terms of functionality, manufacturability and aesthetics. This is accomplished by using PTC’s Pro/ENGINEER Wildfire for the complete design including basic aesthetics, pressed parts, customised injection molded components, and assembly and manufacturing. The overall time from concept to product was reduced by at least 50%, and due to the ease of creating components, assemblies and mechanisms, the company had more time to spend on design refinement. Full structural analysis allowed for optimised material usage and the variety of features available enabled Jetmaster to design each component completely and to pay special attention to even the smallest of them.
The Flygt submersible slurry pump
ProductOne, Tel: (012) 673-9300, Email: prodone@prodone. com, Website: prodeone.com
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three different modules with the magnetic separators installed in all three modules.
Bernadette Wilson, Multotec Group, Tel:+27 011 923 6193, Email:
[email protected], Website: www.multotec.com
The opposite side
One of the five self-leveling wet drum separators supplied to New Clydesdale Coal by Multotec Magnetics
Spirax Sarco’s PN9000 series diaphragm actuators are designed for spring return (failsafe) action. Versions are available for both spring extend and spring retract spindle. The control air pressure supplied acts on the opposite side of the diaphragm to the springs, compressing the springs to move the spindle to the required control position. The control air pressure can be supplied for on/off or modulating control.
Ideal for fluctuations
Five self-leveling wet drum separators have been commissioned at New Clydesdale Coal by Multotec Magnetics, and are achieving 99.1 % efficiency at this Exxaro mine which exports 95% of its coal product. Developed and introduced to the South African market by Multotec Magnetics, these self leveling wet drum separators are capable of handling fluctuating flow rates and were considered suitable for the New Clydesdale Coal plant as feed rates vary to the plant. The mine was started in 1949 and the coal washing plants are ten years old. Mark Whitter, New Clydesdale Coal plant manager, says that magnetite is used as a medium to separate coal at the plant and the old separators were no longer considered to be efficient. “The magnetite consumption was high as a result of the age of the previous magnetic separators, and the magnets were starting to decay. The mine took a decision to install new separators instead of repairing the old machines. Whittier says that a numbers of factors including financial aspects were considered prior to making the final decision. “Although cost was an important consideration other factors such as technical service and support were also critical issues for us,” Mark says. “Multotec Magnetics was able to offer superior technical support, both during installation and commissioning.” The 550 tph plant, which operates 24 hours a day, six days a week, is split into
The PN9000 series pneumatic diaphragm actuators are a compact range of linear actuators that are available in three diaphragm sizes for matching the requirements of valves at various differential pressures. Each actuator is fitted with a mechanical travel indicator and incorporates a fully rolling diaphragm, which provides good linearity over the operating stroke. Various types are available including standard, electroless nickel-plated, stainless steel, spring-extended and spring-retracted. Operating in a -20°C to +110°C temperature range, the actuators have a maximum operating inlet pressure of 6 bar g (600 kPa) and a maximum 30 mm actuator travel. Air supply connection is ¼” NPT (6,35 mm).
Emily Heath, Spirax Sarco, Tel: (011) 230-1300, Fax: (011) 393-1922, E-mail:
[email protected], Http://www.spiraxsarco.com/za
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On the Move
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From:...................................................................................... (insert your name) Title: ...................................................................................... Company: .............................................................................. Bheki Mhlanga Jacques van Wyk Brenton Kemp Address: ............................................................................... ............................................................................................... ...................................................................Code: .................. Telephone: ( Fax: ( ) ....................................................................
Donovan Moss has been appointed managing director of Becker Mining Africa, part of the Becker Group of Companies. Bosch Projects (Pty) Ltd, part of the B & A Group, has appointed Ryno Eskteen as senior project manager and Bill Yeo as technology director. Riaan Erasmus has been appointed Shaun Collins as the financial director at SA French Limited. Bheki Mhlanga has been appointed new buyer at SEW Eurodrive. Advanced industrial technology (Ai-Tec), specialists in the design, manufacture, installation and maintenance of an extensive range of industrial and commercial equipment, has appointed Jacques van Wyk as health and safety manager. Criterion Equipment, a wholly owned subsidiary of Invicta Holdings Limited, has made the following appointment announcements, Brenton Kemp is general manager and Shaun Collins is national sales manager.
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Engineer Placements
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THE SOUTH AFRICAN MECHANICAL ENGINEER
THE SOUTH AFRICAN MECHANICAL ENGINEER
VOL 60
May 2010
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THE SOUTH AFRICAN MECHANICAL ENGINEER
VOL 60
May 2010