Mechanical Technology July 2016

July 2016

THIS MONTH: • Novel approach to transmission towers piloted

• SA hydraulic stalwart more than doubles workshop capacity • Microgrids: a resilient, cost-effective and greener power solution • World-leading nesting software for profiling and sheet metal cutting

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⎪ Comment ⎪

P U B L I C A T I O N S CR O WN

Competition, cooperation and success W hen I was a younger employee, I remember being taken on an Outward Bound team-building course with my colleagues. Following painful amounts of hiking, interspersed with challenges to body and spirit, we arrived at a dam for the afternoon and were split into two teams. Each was given barrels, rope and planks and told to build a raft, set it afloat and make a cup of tea onboard.

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After several hours of battling, it was made apparent to us that one team had too many barrels and too little rope, while the other had too few barrels and too much rope. It was also put to us that this wasn’t a contest. Enthusiasm on both sides immediately evaporated but resources were pooled, one raft was made and opposing team members drank two cups of tea. Competition is the cornerstone of free-market economics. Anti-competitive business practices are seen as a betrayal of the consumer and the natural forces of supply and demand are sacrosanct. Competition is also used to measure our success as individuals. In sport and at school; in our friendships and when dating; when looking for employment or when trying to secure a place for further education, we and our children are forever striving to ‘get ahead’. The argument goes that, without competition, motivation to succeed is lost, causing complacency. If one is unable to compete, one becomes ‘a loser’. Businesses, too, often see themselves as competing entities, striving to be the ‘World Number 1’ in the construction/mining/car manufacturing industry. Does that make the World Number 2 a loser? Featured in this issue is sassda’s AGM. At the start of the chairman’s report Charles Cammell pointed out that sassda is a “pro-competitive association” that does not “discuss issues which expose us to any form of anti-competitive behaviour.” Later in the proceedings, changes to the Memorandum of Incorporation were discussed, to put the association “on a more secure footing with respect to the Competitions Act.” Yet, as an association representing the broader expansion goals of the stainless steel industry, sassda is highly cooperative in nature. Its current director, John Tarboton is a champion of the ‘seven features of remarkable associations’, one of them being alliance building – this to: “collectively find innovative ways to advance all of our industries”. Innovative Engineering this month features a trial design for base station transmission towers being implemented by MTN in conjunction with Clean Energy Investments. In the light of unreliable grid-based power, this system aims to improve uptime, while reducing the system’s attractiveness to thieves. Base station sharing, between competing cellular service providers, is being mooted as a core justification for the additional expense. Each network will have its own transceiver equipment in a common cabinet, housed, powered, backed up and cooled by common infrastructure on the same site. Investment and running costs are shared, duplication is eliminated and the physical footprint significantly reduced – potentially three or four-fold. It is hard not to see this as a win-win scenario for customers, the cooperating companies and the environment. Dividing the steel industry though, import duties are being imposed in an attempt to promote local steel production by making it more expensive to import products that can be locally produced. Some see this as unfair to those converters who rely on the cheaper steel imports to remain competitive. They cite government protection of the steel producers as disadvantaging manufacturers, because their input costs have risen. The supply and demand principle has been violated because government is manipulating the ‘natural’ price of steel. In the light of far-from-free market practices by eastern exporters, how can the steel industry be returned to success unless both producers and converters are protected? How can the ‘laissez-faire’ economic principle – the complete absence of non-market pressures on prices and wages – ever lead to the economic well-being of the country as whole? I am not a believer in absolutes. Competition has its role. Primarily, it enables benchmarks to be set against which personal and/or company performance can be measured. Competitive manufactur- ers of good quality products should be emulated – and they are. But the success of such companies is almost always a collective effort of people cooperating to achieve a common goal, a goal that is far more often based on ‘being the best we can’ than ‘produc- ing at the cheapest price we can’. Cooperation comes less naturally to us than competition though, as I discovered when trying to make a better raft than a team of randomly selected colleagues. For the future economic success of our nation and that of the individual citizens within it, we need to work hard to find ways of cooperat- ing that protect all struggling businesses and citizens, while disadvantaging no one. Peter Middleton

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Mechanical Technology — July 2016

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⎪ July 2016 contents ⎪

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ON THE COVER

FEATURES SPECIAL REPORT 8 Microgrids: a resilient, cost-effective and greener power solution

On June 8, 2016, ABB inaugurated an integrated solar-diesel microgrid installation at its Longmeadow facility in Johannesburg. MechTech talks to ABB South Africa’s sales manager for microgrids and grid automation, Tony Duarte. POWER TRANSMISSION, BEARINGS, BUSHES AND SEALS 12 Don’t be bearing-wise and seal-foolish Andre Weyers, SKF platform manager for southern Africa, talks about SKF sealing systems and how sealing performance optimises product and plant efficiencies by extending equip- ment service life and boosting uptime for ultimate profitability. 14 Effective tools and fasteners enhance reliability 17 Bearing root-cause failure analysis service 19 Effective maintenance is key to productivity COMPUTER-AIDED ENGINEERING 20 SigmaNest minimises waste and cutting costs MechTech talks to SigmaNest product manager Hannes Pretorius of MECAD Systems about this world-leading profile cutting and sheet metal CAD/CAM software solution. 23 Robot Bike: optimised, 3D printed and customised for every rider HYDRAULIC AND PNEUMATIC SYSTEMS: POWER PACKS, COMPRESSORS AND VALVES 24 SA hydraulics stalwart more than doubles workshop capacity Following over 40 years in downtown Johannesburg, Axiom Hydraulics has relocated into an expanded facility in Wadeville, Gauteng. MechTech visits the new premises and talks to company director, Neil Simpson. 27 Compact cast iron gear pumps with 19 000 configurations 28 State-of-the-art pneumatic production facility now fully operational 29 Compressed air rental services launched STRUCTURAL ENGINEERING MATERIALS, METALS AND NON-METALS 30 Sassda: moving towards the remarkable Southern Africa’s Stainless Steel Development Association (sassda) held its 2016 AGM on June 22 following a one day seminar entitled ‘Stainless steel and the fight against corrosion,” MechTech reports. 32 Materials engineering in practice: musings on standards 34 Rectagrid creates space in facilities 35 Polyester fibres for cured-in-place pipe liners INNOVATIVE ENGINEERING 36 MTN pilots novel approach to transmission towers MTN, through energy solutions partner Clean Energy Investments, is exploring the use of hydrogen fuel cells and dc-powered energy efficient cooling solutions for use in its base sta- tion transceiver towers. MechTech talks to Gavin Coetzer MD of Clean Energy Investments. REGULARS 1 Comment 4 On the cover: Compressor Technique expands range to better meet client needs 6 Industry forum 38 Products and services 40 Nota bene

Compressor Technique expands range to better meet client needs Atlas Copco Compressor Technique in South Africa is expanding its offering of industrial compressors, nitrogen and oxygen generators, air treatment equipment, blowers and low-pressure compressors and air treatment solutions to better meet application-specific needs in the local market. MechTech talks to business line managers Charl Ackerman and Pieter van Wyk. For more information contact: Atlas Copco South Africa Innes Road, Jet Park, Boksburg Pieter van Wyk or Charl Ackerman: +27 11 821 9144 or +27 11 821 9113 pieter.vanwyk@za.atlascopco.com charl.ackerman@za.atlascopco.com www.atlascopco.co.za

Mechanical Technology — July 2016

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⎪ On the cover ⎪

Compressor Technique expands

Atlas Copco Compressor Technique in South Africa is expanding its offering of industrial compressors, nitrogen and oxygen generators, air treatment equipment, blowers and low-pressure compressors to better meet application- specific needs in the local market. MechTech talks to business line managers Charl Ackerman and Pieter van Wyk.

A tlas Copco is continuing to expand its premium GA, GA+, GA VSD and GA VSD+ com- pressor ranges, most recently with the inclusion of 200 and 250 kW VSD (variable speed drive) versions of its GA oil-injected, screw compressors. “We had a gap in our VSD range between 160 and 315 kW. We have now closed this gap with the inclusion of VSD versions for our GA 200 and GA 250 models,” Van Wyk reveals, adding: “while VSD com- pressors are not widely used in mines, we have seen immediate success with these energy conscious clients.” Operating at medium to high pressure – 5.5 bar up to 13 bar – the GA range is ideal for the manufacturing sector, typically energising robots, actuators and clamps on automatic production lines. Talking about the role of VSD versions, Van Wyk explains that if a compressor can be run at maximum capacity, 24/7, then the addition of a VSD is not neces- sary. “But if the compressors are regularly run at below maximum capacity, then it is usually more efficient to use a VSD

to match the compressor’s speed to the compressed air demand,” he explains. Hence the need for the two new addi- tions, so that compressors with smaller motors can be used for 200 and 250 kW VSD applications. “These additions give us energy efficient VSD compressor op- tions spanning the power range all the way from 7.0 to 315 kW,” Van Wyk tells MechTech . “By combining a fixed speed compres- sor with a second VSD compressor, one can cater for both variable demand and, at the same time, provide a level of re- dundancy for situations when one of the compressors needs to be serviced. And if full redundancy and variable flow are required, we recommend two fixed-speed compressors plus a VSD, with the two fixed speeds being alternated to supply minimum continuous demand and the VSD providing the variable top-up flow,” he adds. On the ultra-high efficiency side, Ackerman says that the permanent magnet VSD+ range of compressors is also being extended. “Our GA VSD+ compressors have been completely re- designed to make best possible use of Atlas Copco-patented permanent magnet (PM) motor and drive train technology. “When used on a variable speed application, VSD+ compressors offer up to 50% better energy ef- ficiency as compared to their fixed speed siblings,” he assures. In addition, permanent magnet motors and the new compressor design enable full speed operation at better efficiencies than fixed speed equivalents. “The PMmotor enables a VSD+ compressor to be used at up to 100% of its rating without effi- ciency drop off,” Ackerman explains, adding that the GA VSD+ range with permanent magnet motors has been extended to include options of up to a 75 kW nearly twice the capacity of the previous largest (37 kW).

With the inclusion of VSD versions for its GA 200 and GA 250 models, Atlas Copco has now closed a gap in its oil-injected screw compressor range. “This is a game-changing innovation for general industry. The GA 7-75 VSD+ variable speed drive compressor range offers improved performance, silent op- eration (down to 62 dB) and a compact footprint, thanks to its vertical drive train design. “The patent-pending PM motor has been in-house designed and is directly coupled to Atlas Copco’s best-in-class screw element. This technology will set new standards in the industry for years to come,” Ackerman believes. Low-pressure solutions Also expanding is Atlas Copco’s low-pres- sure range. “Low pressure compressors are widely used for wastewater treat- ment; pneumatic conveying of powders such as cement or dry food powders; for iron smelting furnaces; and in the chemical industry for processes such as sulfation. Across our ranges, which include roots and screw type blowers; screw and centrifugal compressor op- tions; along with multistage centrifugal compressors, we have low-pressure solu- tions from 200 mbar to 4.0 bar delivering air flows from 20 to 55 000 m 3 /h,” Van Wyk notes. “In the past, we have been weak in this area. We had a screw (ZS) and a centrifugal (ZB) offering, but these had a maximum capacity of 160 kW. Our ZS offering now goes up to 355 kW, and these also now include VSD options,”

Atlas Copco’s GA VSD+ compressors have been com- pletely redesigned to make best possible use of patented permanent magnet (PM) motor and drive train technology.

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Mechanical Technology — July 2016

⎪ On the cover ⎪ range to better meet client needs

and allowing the trapped gas to discharge to atmosphere.” he explains. For foundry use and for laser cutting applications, for example, the compres- sors, nitrogen or oxygen generators, tanks and pressure boosters can be assembled onto a common skid. “So we can deliver a plug-and-play gas solution to foundries and fabricators – and by using a pressure booster, we can typically provide nitrogen to a laser cutter at 25 bar and up to 40 bar, if needed,” he adds. Specialised solutions Atlas Copco also offers specialised compressor ranges for key industries. “We have a railway range, for example, which will be very useful for the new rail rejuvenation projects currently be- ing implemented in South Africa. Our GAR railway compressors are used for operating brakes, doors and toilets on train locomotives and coaches all over the world and will be ideal for use on the 600 Alstom X’Trapolis Mega passenger trains being built in South Africa by the Gibela Rail consortium for PRASA or by Bombardier for the new Transnet Freight Rail fleet currently under construction,” Ackerman says. A full medical range, which conforms to the SANS 7396 standards for medical gases is also on offer for hospital qual- ity air – for breathing and for powering surgical instruments. “These expansions are enabling us to be competitive in a much wider range of applications,” continues Van Wyk. “And while Atlas Copco has deliberately cho- sen to operate in the premium segment of the market with a broadening product range, increasingly, customers are un- fairly comparing our full-featured quality products to lower cost brands,” he says. “So we have also launched Atlas Copco ranges that maintain our qual- ity standards but do not have all of the functionality and class-leading energy efficiency associated with our flagships. These are simpler, less expensive ver- sions that preserve the quality and reliability associated with Atlas Copco branded compressors and air treatment products. “Along with all of our other range ex- pansions, these further enhance our pre- ferred supplier status.” he concludes. q

99,999% purity. Pressure swing adsorp- tion, on the other hand, can achieve that purity with a 4:1 ratio,” Ackerman explains. “But for lower purities, membrane technology becomes more efficient, with a purity of 98% being the break-even point between the two. So for nitrogen purities between 95 and 98%, we recom- mend using membrane technology, while for higher purities, our NGP swing ad- sorption solution is better,” he suggests. Typical uses of lower purity nitrogen include inflating car tyres (95% purity) and fire suppression. “For food preserva- tion applications, such as filling potato crisp packets with nitrogen before sealing them, or for preserving maturing wine, 99.5% is required. And we have recently supplied high-purity units in Cape Town for packaging biltong,” Ackerman says. Van Wyk adds: “Food and beverage industries are less affected by the down- turn, so we are experiencing strong sales growth for all of our products at food, chocolate, soft drink and beer manufac- turing plants.” Membrane technology separates nitrogen in compressed air from oxygen and water vapour. The compressed air is passed into the cores of bundled semi- permeable membrane fibres. The larger nitrogen molecules travel directly up the cores to the outlet, but the smaller oxygen and H 2 O molecules permeate under pres- sure through the membrane walls and are discharged to atmosphere. “The technology can produce rela- tively high volumes and since water vapour also permeates, the nitrogen is inherently dry,” Ackerman says. PSA adsorption, on the other hand, relies on molecular sieves, which work in a similar way to desiccant dryers. If producing nitrogen, the sieves trap and isolate oxygen and water vapour molecules, allowing the nitrogen to pass through. The principle can also be used to produce high purity oxygen, however. In this case, the sieve material isolates the nitrogen molecules and the oxygen passes through. Once the molecular sieve material in a vessel is saturated, the unit ‘swings’ over to a new adsorption vessel, while the saturated one is regenerated. “This is done simply by releasing the pressure

he reveals. “The centrifugal ZB range was previously limited to 132 kW, but we can now go up to 250 kW, with VSD options available for most compressors in the range,” he says, adding, “we can also cater for larger flows and sizes with our multistage centrifugal (ZM) range. “In the municipal space, we have had visibility problems. Wastewater plant op- erators seldom know about the difference between screw and centrifugal technolo- gies. All they know about is the common roots-type blower, which is not always the most effective or efficient option. “Going forward, we can now offer best-fit solutions for almost any applica- tion requiring low pressure compressed air,” he explains, before suggesting that “the different technology options and their advantages really need to be prop- erly introduced to the market”. Nitrogen and oxygen generators Another key product for Atlas Copco Compressor Technique is its range of nitrogen and oxygen generators. “Com- pared to the on-demand ordering of gas bottles or tanks, on-site production of nitrogen or oxygen offers cost savings, flexibility and continuous delivery advan- tages,” says Ackerman. For nitrogen production, two technolo- gies are available: membrane separation and pressure swing adsorption. “Purities of up to 99.999% can be achieved with either technology but the membrane technology is less efficient for producing high purity nitrogen, requiring an air to nitrogen ratio of about 7:1 to produce a

Mechanical Technology — July 2016

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⎪ Industry forum ⎪

Pioneering solar aircraft arrives in Europe

ates who have completed their B-Eng (Electronic Studies) with a minimum 75% average. • Automation engineers, both graduates seeking to pursue this career path and experienced professionals. • Application engineers with more than five years’ experience working with drives, and offering solutions for the mining, oil and gas industries. • Engineers with a Government Certificate of Competency (GCC) in mines and works are currently more marketable than engineers with GCCs in factories. Naturally, being in-demand skills also means these are mostly scarce skills. Em- ployers are acutely aware of this, and have adopted appealing retention strategies to ensure once they’ve attracted these skills, they’re able to successfully retain them too. www.networkrecruitment.co.za of 1 200 visitors when compared to the 2015 event. This makes it the largest fire, security, and occupational health and safety show in Africa,” says Joshua Low, A-OSH EXPO Event Director at Specialised Exhibitions. A targeted educational campaign, which included the Saiosh conference, the half-day FPASA InFiRES Seminar, as well as the free-to-attend NOSHEBO Seminar Theatre sponsored by Ansell, and the PASMA Working at Height Theatre, were all drawcards. In total, 337 del- egates attended the conferences and most of the free-to-attend seminar sessions were at full capacity. www.aosh.co.za Solar Impulse represents just the opening stage of a new golden age of environmentally friendly transportation. “We are seeing huge new opportunities in the field of sustainable transport,” says Spiesshofer. “Recent technologi- cal developments are opening the way to major advances in energy efficiency and productivity. We are only just begin- ning to realize the full potential of these changes.” new.abb.com more practical thanks to the develop- ment of new fast-charging stations; more sustainable solutions in marine transport with ABB’s Azipod propulsion systems, which place electric drive motors in sub- merged pods beneath the hulls of large ships; and the company’s OCTOPUS advanced connectivity solution that pro- vides guidance to ship operators on the most efficient routes to follow.

In spite of the tough economic conditions, this year’s event saw a visitor number increase of 9.16% to 2 669. This can be attributed to a number of factors in- cluding the high quality of products and services on offer from the 87+ exhibitors at the show, the range of educational con- tent and a number of product launches and competitions that the exhibitors ran on their stands. This year welcomed 21 first-time exhibitors on the show, from over nine international countries. “When combined with our co-located security and fire exhibition, Securex, the show welcomed just over 9 000 visitors in just three days, an increase much more efficient if all of these tech- nologies were implemented on a wide scale. This is exactly what our partners at ABB are doing – applying these in- novations in a way that the entire world can use them.” ABB’s CEO Ulrich Spiesshofer noted that the company provides an expand- ing range of products and solutions that increase the efficiency of transport sys- tems while reducing their environmental impacts on multiple fronts. “At ABB, we seek to find new ways to run the world without consuming the earth,” said Spiesshofer. These include: regenerative braking systems in electric trains, trams and other vehicles through ABB’s ENVILINE product portfolio; electric buses and other EVs, which are now becoming much

Solar Impulse, which has a wingspan greater than a 747 but weighs about as much as an ordinary passenger car, uses a high-capacity lithium-polymer battery system to permit it to fly through the night as well as in full sunlight.

Solar Impulse, a groundbreaking solar aircraft, has completed a 71-hour trans- atlantic flight from New York to Seville in the course of its remarkable round-the- world journey, which began last year in Abu Dhabi. The plane relies on the new- est generation solar cells, batteries and lightweight composites to accomplish the once seemingly impossible task of flying around the globe without consuming any fossil fuels. One of the aircraft’s two pilots, André Borschberg says: “This aircraft is essen- tially a flying smart grid, using the energy collected from renewable sources and then providing it efficiently to users who may require it at a different period of time from when it was generated.” The project’s other pilot, Bertrand Piccard, who is Solar Impulse’s initiator and chairman, adds, “The world could be

High calibre visitors at A-OSH EXPO 2016

The 7 engineering skills most in demand in SA “Although there is still strong demand for engineering candidates generally, there are a handful of highly sought-after skills that SA’s engineering employers are clamouring to get their hands on right now,” says Bel- lah Nxumalo, senior specialist recruiter at engineering recruitment specialist, Network Recruitment.

technical qualifications, but also long-term tenures with companies and the right bal- ance between a candidate’s ‘people person- ality’ and their go-getter, target-smashing sales persona,” she adds. The engineering candidates currently topping SA employers’ lists, according to Nxumalo, are: • Black engineers with experience working on the national energy grid. • ECSA-registered substation and trans- former designers with seven to 10 years’ experience. • Sales engineers with three to seven years’ experience and a proven sales track record selling in the automa- tion, drives and factory automation industries. • Embedded software development gradu-

“As surprising as it sounds, years of experience is not necessarily the chief re- quirement associated with all these skills. Some skills are so desirable, employers are picking candidates straight off the graduate line and investing in these employees early on to grow their fresh new skills within the parameters of their organisations’ specific processes,” she says. “Other positions, like those involving sales engineers, not only demand the right

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Mechanical Technology — July 2016

⎪ Industry forum ⎪

Compressor donation helps care centre create jobs

In brief Local IT Asset Disposal (ITAD) specialist Xperien , together with IT Asset Management specialist services company ITAMSA , has now introduced the first IAITAM certification train- ing in South Africa. “An IAITAM Certification award shows the IT world that the holder is an IT professional that is prepared to handle the tasks necessary for the role of IT Asset Manager,” says ITAMSA managing partner Steve Klements. The Capital Equipment Group (CEG) of Invicta Holdings Limited has appointed Chris White- head as managing director of DISA Equipment (Pty) Ltd, trading as Doosan Construction Equipment . Whitehead is now responsible for all Doosan Construction Equipment operations within South Africa. WearCheck has further enhanced its oil analysis and reliability solutions services with the recent appointment and promotion of several skilled specialists: David Schumacher as diagnostician for the Durban condition monitoring labora- tory and Steven Lara-Lee Lumley as technical manager for WearCheck Durban; Thomas Madlala is now head of business development and technical support at WearCheck Steelpoort with Josephine Rakolota dealing with sales and customer support; and Sharon Pieterse has joined WearCheck Rustenburg to handle busi- ness development and technical sales. Konecranes has established a parts distribution centre (DC) in Johannesburg, South Africa. The centre, which services the whole of sub-Saharan Africa, provides full support to customers with fast turnaround times for queries and orders. “Our highly-trained spare parts team offers as- sistance in identifying the right parts and our southern African Parts DC has high availability of parts in stock, which has resulted in a signifi- cantly better delivery punctuality,” says Celeste Viljoen, DC operations manager. Following a decision to increase its footprint in the SADC region, Goscor Lift Truck Company (GLTC) it has appointed several new distributors in neighbouring countries. The latest is the ap- pointment in Gaborone, Botswana, of Brenham , a general industrial sales and service organisa- tion, which is owned and managed by Ronnie van der Nest and David Nunes, both highly experienced in servicing and sales of machinery. Besam door systems from ASSA ABLOY En- trance Systems are operating seamlessly at the head office and three franchises of one of South Africa’s largest fast food companies. Following the first installation of Besam Unislide bi-parting doors at the Johannesburg head office, the com- pany has placed an additional two orders for the installation of entrance and exit door systems at its Kathu and Krugersdorp franchises.

Rockwell Automation is strengthening its vision of becoming the leading provider of industrial automation and information solutions and services in sub-Saharan Africa with the inauguration of its new Johannesburg premises. The occasion coincided with the announcement of the joining of forces with two well-known and influential South African trusts, Ma Afrika Tikkun Endowment Trust and Simanye Trust, as their B-BBEE shareholder. This collaboration represents an op- portunity “to pursue a focused strategy based around education, employment and enterprise opportunities that can make a genuine contribution to what we see as our responsibility to uplift underprivileged communities,” explains Barry Elliott, managing director, Rockwell Automation sub-Saharan Africa. Maranatha Care Centre in Benoni uses a Ceccato compressor donated by Atlas Copco to do various repair and mainte- nance jobs around the facility including building fences, putting up burglar bars and even pumping tyres. “We help to cre- ate employment opportunities for jobless and homeless people by assigning this type of work to them,” explains Lukas van den Bergh who founded the Care Centre in 1991. Maranatha Care Centre is a haven for the homeless and destitute, providing much needed food, shelter, clothes and counselling. “We also provide transport to and from doctors, dentists and schools and we even monitor and assist learners with their homework,” adds Van den Bergh. He explains that the aim of the Care Centre is to assist people in such a way so that they are able to again enter the workplace. The facility is currently caring for ap- proximately 46 adults and 12 children re- siding independently on plots in Brakpan. “While they are basically taking care of themselves, we have provided temporary homes and we also send weekly food donations to assist them until they get back on their feet,” he adds. “We can accommodate approximately 80 people in total.” Kgothatso Ntsie corporate communica- tions manager for Atlas Copco Holdings South and Sub-Sahara Africa, accompa- nied by Multi Brands’ Sibongile Mtaopane, business line manager and Katlego Ntsie,

sales and marketing specialist, handed over the Ceccato Beltair Pro 90 compres- sor to the centre in May 2016. “Suitable for any application that requires dry air, the stationary two-stage belt-driven piston compressor features a pre-installed and tank-mounted dryer to deliver top performance and quality air,” says Mtaopane. “This all-in-one quality air solution will save both time and costs while the machine’s reduced footprint also offers the advantage of space saving during storage.” Says Ntsie: “Our support of a number of organisations goes beyond once-off donations of cash, products and other goods; we build long-term partnerships with them, identify and meet their real needs and we are able to see the progress they make over time; this is how Atlas Copco makes a difference.” www.atlascopco.co.za Katlego Ntsie, Multi Brands; Kgothatso Ntsie, Atlas Copco; and Sibongile Mtaopane, Multi Brands, hand over the Ceccato Beltair Pro 90 compressor to Lukas van den Bergh. “It’s not just corporate social respon- sibility, it’s a social licence to operate,” Elliott continues. “We looked for a strate- gic shareholder through whom we could make sure our social development objec- tives could achieve maximum impact in the communities and people that need it most. This is a long-term investment in our country.” Afrika Tikkun, with its Cradle-to- Career model that supports children from infancy into adulthood, has helped close to 20 000 beneficiaries per an- num for the last 21 years become more employable, productive and responsible, enhancing their self-efficacy. “Afrika Tikkun is the perfect vehicle to match the corporate social responsibility objectives of Rockwell Automation,” says Elliott. www.rockwellautomation.co.za

Rockwell automation strengthens roots in Africa

Mechanical Technology — July 2016

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⎪ Special report ⎪

Microgrids, a resilient, cost-effective

On June 8, 2016, ABB inaugurated an integrated solar- diesel microgrid installation at its Longmeadow facility in Johannesburg, which comprises a grid-connected system with full on- and off-grid functionality that maximises the use of renewable energy and ensures uninterrupted electricity supply. MechTech talks to ABB South Africa’s sales manager for microgrids and grid automation, Tony Duarte (left).

“ T raditionally, utilities depend on a concentrated region of generation. In South Africa, for example, the largest percentage of our power comes from the coal-fired power stations in Mpumalanga and Limpopo, where the coal mines are,” begins Duarte. “But with many power stations in- terconnected, critical points of failure emerge, which can have serious affects on the whole system,” he says. “Microgrids are networks of smaller independent but interconnected generation ‘islands’ designed to service local power needs. A fault in one part of the network does not affect the others and, with a degree of redundancy in every microgrid and/or between interconnected microgrids, out- ages can be avoided with other sources continuing to supply power,” he explains. “Microgrids are generation agnostic,” he continues. “They are not fussy about how the power is generated or where it comes from. Essentially, their core purpose is to manage and combine the available power to best meet demand. “Gas, hydro, diesel, HFO, solar, wind or geothermal sources can be incorpo- rated into a microgrid solution. But each technology responds differently and their response curves don’t necessarily overlap,

which can make the delivery of seamless power difficult. Hydro and diesel, for ex- ample, can complement each other, but if there is a sudden upset, their response times don’t overlap enough to avoid a disturbance on the grid. On a mill trip on a grid-isolated mine, the response times of a base-load hydro plant might be a few seconds. The diesels will try to compen- sate, but these are too slow in starting additional units. This can cause the circuit protection to lift, so the whole mine can go into a blackout state,” he relates. Exemplifying the critical role of microgrids is the Longmeadow dem- onstration plant, which combines the grid-based supply from Johannesburg’s City Power; the facility’s existing diesel backup generators; a newly installed solar PV plant; and a compact and ver- satile PowerStore TM battery-based grid stabilising system to address frequency and voltage fluctuations. “If City Power cuts out now, the PowerStore needs to respond quickly enough so that no one sees a dip in power. “This is fundamental to microgrids. They need to incorporate fast acting mechanisms or generation sources to fill in the gaps while the preferred al- ternative source ramps up. Effectively, the PowerStore compensates for a lack

of overlap and ensures system stability, regardless of fast fluctuating conditions on the grid, step changes in the load; or variations associated with renewable energy sources,” Duarte explains. “Batteries and flywheels are ideal for meeting this need, because the connect- ed inverters switch at electronic speed, so they react within a few milliseconds, which is well within a single cycle of a 50 Hz ac supply,” he explains, adding that a fly wheel or battery storage system can react in milliseconds. Describing the problem with tradi- tional grid-connected PV power plants, he says that PV solar generally needs a frequency and voltage reference signal from a live grid before it can be synchro- nised. “Systems such as those adopted for the REIPPPP are grid following. If the grid trips, then the PV plant also trips. This negates the usefulness of grid-connected PV as a backup power solution,” he tells MechTech . “If the grid goes into a blackout state, the PV system cannot help. So if used in this way, PV solar and wind generation can never be a substitute for base-load generation because they cannot replace the loss of grid power,” he explains. ABB’s microgrids, however, are grid forming. “While they will synchronise to a grid if it is available, they can also provide the references for renewable and fossil energy generation to follow. PowerStore sits between the grid and all the other generation sources, so PV, diesel and wind generation will all look to the PowerStore reference in order to synchronise.

An infographic outlining the key features of ABB’s microgrid installation at Longmeadow.

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Mechanical Technology — July 2016

⎪ Special report ⎪

and greener power solution

Above: ABB’s Longmeadow facility now has a 750 kWp, monocrystalline rooftop PV system connected to a microgrid. Above right: A PowerStore TM battery-based grid stabilising system takes up the load immediately when the grid goes down. Right: The dc power from the panels is passed through a single PVS 800 630 kW ABB inverter to generate the ac supply. “So while microgrids can be grid con- nected, as we see at our demonstration plant here in Longmeadow, they are also 100% ‘islandable’. Here, we have grid- connected power, PV solar generation, the battery and diesel generation all interconnected via a common ring and automatically managed by the Microgrid Plus distributed control system (DCS). The unique feature of ABB’s microgrid control system is that it has a distributed network of controllers allowing for redun- dancy, expandability and maintenance to take place without interrupting genera- tion of power. “As soon as an outage is detected, the PowerStore provides the reference for off-grid generation. Then, when the grid comes back on line, the PowerStore resynchronises, which will cause the off- grid generation sources to follow. The grid can then be safely brought back into the supply mix,” he adds. Key features of microgrids The core purposes of ABB’s microgrid solutions is power security and grid resilience. Since no single generation option is able to offer this all of the time, it makes sense to combine power generation sources to make sure power is

generation itself,” he informs MechTech . A second objective is to achieve the lowest possible levelised cost of energy (LCOE) from a combination of generation sources. “Levelised cost of energy is a stream of equal payments, normalised over the expected energy production period, that would allow a project owner to recover all costs – including financing and an assumed return on investment over a predetermined financial life. This value is expressed as a tariff per kWh of generation,” he explains, adding, “gener- ally calculated for a 20-year life.” With this information, ABB’s Microgrid Plus DCS is able to optimally combine available generation sources to meet prevailing load demand at the lowest possible cost. And the third important imperative

always available. “While seamless power changeover is not always necessary, it is now a primary part of our offering and is often essential,” Duarte suggests. “Probably the largest microgrid market is in the USA, where you would think they have no need of it. Why? Because of the increasing occurrence of natural disasters, which tend to take out the grid and cripple the affected community. To minimise the impact of such events, the power needs to be restored immediately and microgrids are being installed on a redundancy basis to back up the grid in high-risk areas. Typically these are large systems of between 10 to 100 MW, but there is no capacity limit since the technology involves the management and coordination of generation, not the

Mechanical Technology — July 2016

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⎪ Special report ⎪

driving the implementation of microgrids, according to Duarte, “is to reduce the carbon footprint of electricity generation as a whole”. “The management software allows us to make decisions on a mil- lisecond basis as to how to generate the electricity needed in the cleanest way possible,” he says. Talking about advancing renewable penetration, he says that in spite of the rise in installed renewable capacity in South Africa as a result of the REIPPPP, the penetration of renewables in terms of supporting load demand remains low. “Current generation capacity is at around 43 GW and we now have some 3 000 MW of installed renewables. This translates to an installed penetration of around 6.0%,” he says, comparing this to Germany, where up to 78% of daily electricity demand could come from renewables. “But high renewable penetration in- troduces power supply volatility, which creates difficulties for system operators, who need to balance the grid via deflec- tions and stabilisation strategies. “While all renewables are associated with volatility, the battery storage and flywheels embedded in microgrids are an ideal way of managing this. Distributed microgrids, at suburb level for example, can significantly increase overall renew- able penetration, while making the whole system more stable and reliable. Even if hundreds of microgrids are intercon- nected, each one balances itself, so the grid itself is not destabilised in any way by the variations in renewable energy generation,” he assures. Modelling local load profiles Another distinguishing feature of the microgrid is that emphasis is placed on modelling the generation needs based on the load profile of the facility or area to be supplied. “There is a concerted and upfront effort to balance the generation/ supply equation. It is not just a matter of putting up a PV system, connecting it to the distribution boards and hoping it will generate as much power as possible,” Duarte argues. ABB offers upfront power consulting, which results in investment cost savings by ensuring a reliable consumer-oriented system and power quality. Operational cost savings are also achieved: by optimising network configurations and the intelligent use of modern automa- tion equipment; and maintenance cost

The 380 kWh Li-ion battery bank and PowerStore controller are all housed in three ‘plug-and- play’ containers.

quired, the load curves and the response envelopes. The microgrid analysis report includes a business case, which makes for a bankable solution that can be taken directly to a funder. “We strive to find the sweet spot with respect to capex and opex, which, ideally, combines genera- tion options for lowest LCOE, highest reli- ability and resilience and least possible environmental impact,” he adds. From a reliability perspective: “ABB has over 25 years of experience in this field and its research and development department is turning 100 this year. We have a service and remote monitor- ing capability that enables web-based monitoring to be implemented on any plant anywhere in the world,” he says pointing towards the prevailing genera- tion and load profile of the Longmeadow demonstration plant.” The online monitoring system shows PV generation at 364 kVA, with the grid draw being reduced to 650 kVA on a 1.14 MW load. “In the event of a grid outage, it will first bring in the PowerStore from batteries, and if the outage lasts longer than 15 or 20 minutes, the diesel generators will automatically kick in to meet demand load,” he explains. In the municipal context, there are numerous ways that Microgrids can play a major part, not only in the southern African region, but especially in South Africa too. Across Africa, Duarte sees modular and containerised microgrid solutions as ideal for augmenting weak grids. “For new factories being mooted in places with power limitations, and mu- nicipalities striving to supply the stable power needed for emerging economies to thrive, microgrids are an increasingly viable option,” he concludes. q

reductions through the implementation of reliability centred maintenance. At the starting point of this offering is a grid study to determine the prevailing load and connecting standards. “If the load turns out to be lower than the gen- eration capacity of the chosen solution, then the initial capex investment will never be used to its potential. Conversely, if the renewable component of a chosen system is too small, then the likely return on investment will also be low, as will emissions reductions. “As part of our grid study, we also determine how to comply with local regulations. Whether in rural Africa or here in Longmeadow, systems must all comply with power quality requirements and safety regulations,” he says. Adding to this offering is a steady state analysis – how much power is needed under normal operating condition, which governs the overall capacity (kVA) of the microgrid – and a dynamic analysis model is also needed: “The effects of step loads being introduced, the need for critical loads to retain their supply and the impact of partial supply outages all need to be taken into account,” Duarte explains. “This helps to size the battery store or flywheel capacities, for example. It also helps to identify ways of expanding the system, when the need arises.” Depending on the size of the system and the variety and number of genera- tion sources, the complexity of microgrid increases. To cater for this, visualisation and automatic control functionality has to be introduced – “and this is where ABB really excels,” believes Duarte. From the analyses performed during the consulting phase of a project, ABB is able to make specific recommendations about the generation components re-

Mechanical Technology — July 2016

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⎪ Power transmission, bearings, bushes and seals ⎪

Don’t be bearing-wise and seal- foolish

Andre Weyers (left), SKF platform manager for southern Africa, talks about SKF sealing systems and how sealing performance optimises

product and plant efficiencies by extending equipment service life and boosting uptime for ultimate profitability. ficiently will compromise even the best quality bearing, subjecting it to prema- ture failure,” says Andre Weyers, SKF platform manager – Southern Africa. “So when fitting good quality bearings due consideration must also be given to the quality of the sealing system.” The SKF range of seals are specially designed and engineered in accordance with ISO 6194 and DIN 3760 to con- tinue delivering optimum sealing per- formance, while withstanding thermal expansion, dynamic run-out and shaft- to-bore misalignment. Alongside quality, specifying the right sealing solution for the application is

S KF, globally renowned for its reputation and leadership in the supply of quality products and expert services, has been the undisputed market leader in the bearings business for over 100 years. The enhance- ment of SKF’s bearing offering through its core technologies – seals, lubrication, power transmission, mechatronics and services – perfectly position the company as a turnkey solutions provider. The sealing system’s ability to retain lubricant and prevent ingress of aggres- sive contaminates is fundamental to bearing performance. “A sealing system that does not perform reliably and ef-

The SKF Agri-Hub for fertiliser injector discs has been specially engineered to boost farm productivity and

profitability through increased performance and improved machine uptime, while mini- mising impacts on the environment. equally important. “This is where our knowledge of local industries forged over more than a century sets us apart,” notes Weyers. Benefits from SKF’s in-house de- signs include exceptional compatibility, improved wear resistance and aging as well as increased pumping ability, which pushes lubrication away from the seal lip. SKF seals’ superior quality materials are able to withstand the corrosive prop- erties of synthetic additives increasingly used in oil, which cause extensive wear of seals manufactured from inferior, run- of-the-mill materials. Another key feature of SKF seals is their exclusion capability. In SKF’s patented WAVE seal design, the seal is moulded to push oil and contaminants

Left: The exceptional sealing performance available from the SKF Sealing Systems’ range optimises product and plant efficiencies.

Below: SKF Mudblock seals are designed with an integrated wear sleeve and a rubber inside diameter, but can have any one of a number of sealing lip and auxiliary lip configurations. The design of SKF Mudblock cas- sette seals has been optimised to provide excellent retention of either grease or oil and maximum protection against liquid or solid contaminants.

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Mechanical Technology — July 2016