Client Focus

ZEST WEG PIONEERS REMOTE WITNESS FACTORY ACCEPTANCE TESTING UNDER COVID-19 LOCKDOWN

In an innovative ‘first’ to keep a customer’s mining project in the Democratic Republic of Congo (DRC) on schedule despite the impact of Covid-19, Zest WEG successfully conducted a remote witness test of Medium Voltage (MV) Variable Speed Drives (VSDs) in WEG’s Brazil factory.

“These are extraordinary times, and require extraordinary measures,” says David Spohr, business development executive for high-voltage equipment at South African-based Zest WEG. “With the restrictions on international travel, we had to think creatively about how to complete this final step in the manufacturing process – the witnessed Factory Acceptance Test (FAT) – before the equipment could be shipped to the DRC site.”

Under normal circumstances, these tests would require the customer to travel to Brazil and spend a week at the factory witnessing and signing off a range of detailed test and equipment requirements.

This order comprised two 7MW 3300V WEG MVW01 VSDs for the ball and SAG mill drive application and two 1,2MW 3300V WEG MVW01 VSDs for the HPGR mill application. Both applications required non-standard features, namely “frozen charge protection” software on the ball and SAG mill application and a “master & follower” configuration on the HPGR mill application.

“It was essential that we did not delay the customer’s project, so we arranged to conduct the witness test using web-based communication software,” says Spohr. “This allowed the participation of Zest WEG experts, the engineering contractor and the end-user, all from the safety of their homes in Johannesburg – communicating with five testing technicians in the WEG factory in Brazil.”

Using a high-definition camera and web-based communication software, the factory technicians were able to walk the contractor and end-user through each element of the FAT, with clear and real-time visual images of the test results and equipment on the factory floor. The tests continued for three days, beginning at 13h00 and ending at 19h00 to account for time zone differences. Testing covered three key areas – PLC communication software integration, full functional testing and full load testing.

“As with any other witnessed FAT, the customer was provided with a comprehensive results report by WEG,” Spohr says. “This enabled the customer to check, in exactly the same way, that the remote FAT results were within the required tolerances.”

Spohr notes that this pioneering step is likely to influence the way that these tests are done in future. “It has shown that the testing can be done to the same standards, but with significant savings in time and cost,” he says.

Client Focus

CONCOR HEAD RALLIES SA TO FIGHT VIRUS

“South Africa has boldly taken the right steps to avoid the high number of coronavirus-related deaths experienced by many countries; we just need to stay strong, stay healthy and stay at home.”

This is the message from Concor CEO Lucas Tseki as the country enters an extended lockdown for another two weeks.

“This is an historic challenge facing the planet, and we are all called upon to make our own contribution in these difficult and uncertain times,” Tseki says. “The current crisis highlights more than ever how interconnected we all are – across communities, countries and continents. We are all in this together, and must act responsibly toward a common goal of stemming the spread of the virus.”

He commended President Cyril Ramaphosa “for his grit and courageous leadership in the face of adversity”, noting that the decision to extend the national lockdown could not have been easy. The lockdown’s impact on business was clearly front-of-mind for decision-makers, but the global spread of the deadly virus demanded that tough choices be made.

“For Concor’s executive team, our primary focus at the moment is the group’s sustainability, so we continue to engage our business partners and explore opportunities within the market,” he says. “We are doing everything possible to mitigate the financial impact of the coronavirus including preparation for responsible resumption of operations post the lockdown– and we are confident that together we will weather this unprecedented storm.”

Concor is one of the largest players in the sub-Saharan African infrastructure and construction sector, and is a proudly Level 1 B-BBEE company.

Client Focus

ZEST WEG ADDS GEARED MOTORS TO PRODUCT LINE-UP

A range of WEG geared motors – with benefits including efficiency and reliability – will soon be available to customers in South Africa and the rest of the continent from Zest WEG.

According to Zest WEG national sales executive Johan van Niekerk, the WEG WG20 range is a natural extension of the company’s offering in electric motors, and will be available from the third quarter of 2020. The geared motors will be distributed and supported through Zest WEG’s established footprint of strategically located branches and outlets across the continent.

“In keeping with our local production philosophy – and to reduce lead times to customers – the geared units will be assembled in South Africa,” van Niekerk says. “Zest WEG has made a substantial investment in new assembly facilities, including hydraulic presses and assembly tooling.”

He also notes that the geared motors will allow the company to expand services in new markets including the packaging, recycling, food and beverage sectors.

Cas de Jager, Zest WEG geared motor specialist, highlights that local assembly allows reduced time-to-market.

“Underpinning our quick turnaround time will be our skilled employees and local stockholding of a full range of gears, flanges, housings, shafts, bearings, oil seals and other components,” says de Jager.

The components for the geared motors are manufactured by Watt Drive in Austria, an established gear technology specialist and part of the global WEG group. Watt Drive offers a complete range of combinable drive systems for production machines and industrial manufacturing plants. In addition to providing high quality components, the company is also training Zest WEG personnel at its Austrian facility and will regularly send technical experts to continue building capacity in the South African operation.

There are various benefits inherent to geared motors, says de Jager.

“A key improvement delivered by geared motors is their high level of efficiency,” he says. “Only about 1,5% of mechanical efficiency is lost per gear stage, so a two-stage gear unit would be about 97% efficient.” He highlights that they are also very reliable, robust and durability, making them economical to maintain.

Van Niekerk says Zest WEG’s extensive footprint around South Africa and linkages with the rest of the continent positions the company well to introduce the WEG WG20 range to new and existing markets.

“Our geared motors will be given the high levels of service and after-market support for which we are well-known,” he says.

Client Focus

AFRISAM READYMIX FACILITATES DURABLE CONSTRUCTION OF BRAKPAN RESERVOIR

AfriSam’s responsiveness and ability to deliver according to specification made this leading construction material supplier the preferred readymix concrete partner for the new Brakpan reservoir being constructed by Superway Construction.

According to Xolani Mbatha, technical product team leader at AfriSam, the company’s quality readymix creates concrete possibilities for the production of durable infrastructure.

“Productive collaboration between AfriSam and contractors is critical for the successful execution of any project, and this is especially so when it comes to defining and meeting product specifications and facilitating delivery within construction programme scheduling,” he says.

An excellent example of the success of such a cooperative partnership is clearly visible at the site of the reservoir currently under construction at Sallies Village in Brakpan.

The City of Ekurhuleni, as part of a commitment to address water capacity constraints within its region, has embarked on building 29 reservoirs during the period 2018 to 2021. This will see a combined storage capacity of 550 megalitres being added to the infrastructure.

Superway Construction won the contract for the construction of a new reservoir adjacent to the existing Brakpan reservoir amid fierce tender competition. Contract manager, Eugene Gibbard, acknowledges that being awarded this contract is gratifying for Superway Construction and recognises the contractor’s experience in a wide variety of construction and infrastructure projects.

The scope of this project includes the construction of the reservoir and all ancillary works including the perimeter fence, new access road, chambers and guardhouse. Elements where concrete is specifically required include the strip footings, walls, column bases, columns, column heads and roof.

The implementing agent, the Development Bank of Southern Africa, issued detailed project specifications and when completed, the 18-megalitre reservoir will be 8.2-metre-high with a diameter of 60 metres and will have a slightly sloped concrete roof.

AfriSam secured the contract to supply 2 500 m3 of readymix concrete based on its ability to meet the stringent quality specifications. All concrete supplied will be as per the consulting engineers’ material specification for an impermeable water retaining structure.

“Previous experience with AfriSam’s professional technical team and their responsiveness and ability to deliver according to client specification made them the preferred readymix concrete partner for this reservoir project,” Jurie Moolman, Superway Construction site manager, says.

SANS 2001-CC1-2012, the specification for structural concrete that is being used for this project, calls for fly ash as a supplementary cementitious material (SCM). As the standard operational mix supplied by AfriSam’s Sub-Nigel plant contains slagment, the operations team had to be pro-active in introducing a customised concrete mix changing from using slagment to fly ash in order to meet the project requirement.

The slump was initially specified at very low levels between 10 mm and 60 mm. This was of concern considering the high minimum binder content specified, ambient temperatures and the need to pump the concrete. Close consultation between AfriSam’s technical team, Superway Construction and the consulting engineers resulted in an agreed slump on 125 mm in conformance with SANS 878.

The careful calculation of the water:cement ratio to not exceed 0,5 ensured that the tight shrinkage specification of between 0.3 and 0.45 mm will be met. A crystalline waterproofer is incorporated into the mix to further enhance permeability properties while a CHRYSO curing compound will allow adequate cementing reactions to aid strength gain, impermeability, abrasion resistance and durability. A well-graded aggregate is used for this special application.

This custom mix underpins AfriSam’s capability in designing and supplying a fit-for-purpose readymix concrete; in this case a workable mix which accommodates placing techniques and meets the project specification.

The reservoir will be constructed in three lifts for the full circumference, ensuring stability for the reservoir walls. This necessitated a continuous supply of readymix concrete and AfriSam allocated seven readymix trucks to each pour, and when required this was increased to 12 trucks.

Initial planning has already commenced for the roof to be poured in one pour. Moolman says that while this will be a daunting single pour of 630 m3, the volume of the pour will not be the biggest challenge; this will be to ensure an acceptable finish over such a large area. Detailed planning will be done to ensure all the required resources are available to achieve this milestone.

Queen Mabunda, territory sales manager at AfriSam, says that AfriSam has been able to contribute positively to maintaining the integrity of the project. “Our extensive experience and knowledge within the readymix sector and access to resources within the company, including the Centre of Product Excellence, allowed us to provide Superway Construction with the readymix solution it needed on this project. Further, our stringent quality control measures at AfriSam’s Sub-Nigel plant provided the assurance that the customer needed when it came to consistent product quality.”

AfriSam has supplied readymix concrete and technical advice successfully to a number of reservoirs constructed in the Ekurhuleni region. Mabunda says that the timely response of using fly ash to meet the project requirement will position AfriSam well in the market to supply other similar projects.

Work on site commenced in May 2019 with a contract completion date set for June 2020. Prior to the lockdown, Superway Construction was on track to hand over the project by the end of May, ahead of time and on budget.

Client Focus

FLSMIDTH’S LABORATORY CONTRACT AT SALDANHA RENEWED

Automated laboratory leader FLSmidth has had its Operate and Maintain (O&M) contract at the Saldanha Iron Ore Terminal on South Africa’s west coast renewed for another three years.

The company has successfully operated the quality control laboratory at Saldanha – Africa’s largest iron ore export facility – for the past eight years, according to Martin Matthysen, Director, SPA (sampling, preparation and analysis), Sub Saharan African and Middle East at FLSmidth.

“An average of approximately 8500 tonnes of iron ore per hour pass by conveyor from the rail head to the ship during loading,” says Matthysen. “Our automated laboratory located above the conveyor must sample and test from this ore stream, delivering accurate and precise data timeously to stakeholders.”

He says the automated system installed by FLSmidth for a leading iron ore producer takes a representative sample of the ore and processes it though the laboratory with minimal human intervention. It is the only laboratory with ISO 17025 accreditation for the iron ore sector, complying with standards ISO 9516 for chemical analysis, ISO 4701 for particle size determination, ISO 3087 for moisture analysis, ISO 11536 for loss of ignition analysis and ISO3082 for sampling.

“Operational quality and stringent standards are vital in this process, as both the seller and the buyer of the ore must be confident that test results on the shipment are accurate and precise,” he says. “The laboratory analyses the material’s chemical composition, particle size, moisture content and loss of ignition levels – as these indicators all impact on the final price of the product.”

The accuracy of results is further checked by participating in a proficiency testing scheme as well as ‘round robin’ analysis – in which samples are verified by laboratories selected by end-customers elsewhere in the country and world.

“We are pleased to have delivered exemplary past performance at Saldanha, in service of our client’s best interests and efficient operation,” he says. “Our ongoing focus on quality has also ensured that we remain compliant with all-important ISO standards in our daily processes.”

He adds that the automated laboratory’s ability to deliver reliable and accurate results as quickly as it does, is also a vital benefit to the client.

Client Focus

KWATANI’S SCREEN SOLUTIONS CUSTOM-BUILT FOR TONNAGE AND LOWEST TCO

When a South African diamond operation needed to improve the performance of its degrit screens, Kwatani customised a bespoke solution that doubled the feed-rate.

The customer was operating a number of multi-slope screens to dewater product between 0,8 mm and 5 mm in size, before it was treated by dense medium separation (DMS). However, the screens were causing a severe carry-over of water onto the conveyor belt to the DMS.

“The feed-rate on each screen was being limited to about 250 tonnes per hour,” says Kwatani CEO Kim Schoepflin. “We tackled this by designing and manufacturing a customised multi-slope screening machine to fit the customer’s existing footprint.”

Schoepflin says Kwatani’s replacement was able to double the feed-rate to about 500 tonnes per hour, and with minimal water carry-over. As a result of the success of this unit, the customer requested Kwatani to replace the whole bank of screens.

In another contract, a customer asked for assistance with underperforming screens that could not deliver the original design parameters. They also wanted to improve the tonnage throughput by 17%.

“We conducted a careful evaluation in collaboration with the customer, and came up with an innovative and economical solution,” Schoepflin says. “Simply replacing the existing screens with Kwatani’s new larger screens would have been costly and time-consuming, so we decided instead to replace the screen’s existing gearboxes.”

The replacement gearboxes delivered greater vibration, but without exceeding the output torque that the existing motors driving the gearboxes could provide.

“Drawing from our portfolio of locally designed and manufactured exciter gearboxes, we were able to implement this solution very quickly,” she says. “The two new exciter gearboxes were delivered to site and were in operation within two weeks – successfully and immediately increasing the screen’s throughput.”

The benefits to the customer did not stop there, says Schoepflin. The newly optimised operating parameters meant that the material bed depth was lower, so the drive motors drew a lower amperage and reduced the cost of power consumed.

“Our customised screening and feeding solutions – developed by our in-house team of experienced mechanical engineers and metallurgists – are based on consultation with each customer,” she says. “The result is a design that delivers the optimal processing performance and tonnage at the lowest cost of ownership.”

Client Focus

SLURRYSUCKER WINS THROUGH IN SALTWATER APPLICATION

A recent two-week trial on a mine on South Africa’s west coast has again proved the value of Integrated Pump Rental’s SlurrySucker dredging unit – even in saltwater and high-volume conditions.

The mine was facing a real challenge with its main process water pond; it would fill with sediment within a week, and the sea water which filled it is highly corrosive. The mine was also looking for a safer and more cost effective option than the divers, equipped with manually operated suction pipes, it was employing.  

“This large pond – about 70 metres square and eight metres deep – is central to the mine operation as it feeds all the process plants,” says Ruaan Venter, rental development manager at Integrated Pump Rental. “It is therefore vital that sediment is removed continuously, quickly and in large quantities.”

During the trial, the SlurrySucker was able to pump 250 cubic metres per hour of sediment with a solids content of 30 to 40%. This allowed the specialised dredging equipment to remove 60 to 70 tonnes of sediment from the pond every hour.

“When in contact with conventional metal pump components saltwater is extremely corrosive, and over time can cause a lot of damage to the equipment leading to the frequent replacement of wear plates and impellers. In addition, the integrity of the framework will also be compromised,” says Venter. “Under these conditions and to mitigate against corrosion, we provide our customers with a full stainless steel pump solution with rubber-lined pipes to transport material from the pond.”

The success of the trial has raised the interest of other mining operations along this coastline, where sea water is also used in the process plants.

“Demanding conditions like these would warrant the customer considering a purchase option,” he says. “It is likely that the SlurrySucker would be operational every day on these ponds, making this specialised equipment a valuable investment in the efficient running of the plant.”

Client Focus

BCCEI WAIVES LEVIES FOR APRIL AND MAY 2020 BRING RELIEF TO SECTOR

The Bargaining Council for the Civil Engineering Industry (BCCEI) took an unprecedented step in April 2020 when the Council announced that it would waive the BCCEI administration and dispute levy contributions for that month. In another move aimed at bringing much needed relief to an already ailing industry sector, the BCCEI has announced that this waiver will be extended to the month of May 2020.

This is a significant gesture as the BCCEI does not receive any grants or subsidies from the government and its only source of income is through the administration and dispute levies which is received from registered companies in the civil engineering industry. These levies are used for the running and day-to-day operations of this bargaining council.

BCCEI general secretary, Nick Faasen says that the Council decided on the step as it is fully aware of the situation in which both employers and employees find themselves at this time.

“Budgets and cash flow are under immense pressure following the declaration of the National State of Disaster and the subsequent implementation of the nationwide lockdown which was further extended. We acknowledge that many people in our sector will, in all probability, have a reduced income and we believe it is essential that we work together to find ways to reduce expenses, wherever possible,” Faasen says.

The BCCEI, representing two unions and two employer organisations, provides a range of valuable services to the civil engineering sector. Currently, the Council continues to operate through non-contact methods and remains committed to prompt service delivery to the industry.

Client Focus

SKID-MOUNTED DRY-TYPE TRANSFORMER DOES DUTY ON COAL MINE

In a specialised application on a coal mine, Trafo Power Solutions recently supplied a dry-type transformer mounted on a mobile skid.

“The harsh environment of a coal mine required us to specially design a fit-for-purpose solution,” David Claassen, managing director at Trafo Power Solutions, says.

“The cast-resin dry-type transformer is ideal for the mobile arrangement as it is cooled without oil,” he explains. The absence of oil makes it a safer option in terms of fire hazards, especially on a coal mine.

It is also more environmentally-friendly, as there is no chance of an oil spill. The 1250 kVA dual-MV configuration supplied to this mine allows the unit to be linked up to either 11 kV or 6,6 kV supply.

“The unit was designed for a compact enclosure, while still allowing for sufficient air movement for cooling,” Claassen says. “We provided a unique solution of a cast-resin transformer with Class H insulation rating for both the medium voltage and the low voltage windings.”

This insulation standard ensures that the transformer can withstand temperatures of up to 180°C. He notes that the enclosure design had to accommodate these heat factors while also preventing the ingress of dust or water.

Special engineering was also applied to building a high level of mechanical rigidity into the transformer itself, as demanded by the regular relocation of the mobile skid. This movement means considering that vibration and other forces must be borne by the equipment without affecting its performance.

Claassen emphasises that Trafo Power Solutions is experienced in providing dry-type transformers in a range of enclosed formats to suit customers’ needs. The inherent safety of these transformers also allows them to be installed in underground mining locations.

“We can provide various dry-type transformer enclosed solutions with a mobile skid, which is a versatile format for a range of mining applications,” he says.

Trafo Power Solution’s solid track record in cast-resin transformers is based on its local expertise and design capacity, combined with the high quality manufacture of the units by Italy-based TMC Transformers.

Client Focus

SANDVIK’S NEW GENERATION LS312 LOADER HITS SA

Orders are already placed by major South African coal miners for Sandvik’s new LS312 flameproof underground loader.

The first active units will start rolling off the local production line in the second quarter of 2020, according to Richard Hickson, product support manager at Sandvik Mining and Rock Technologies.

“The LS312 loader is an enhanced 12 tonne high-capacity heavy-duty utility vehicle, building on the best features of our 10 tonne LS190 and 12 tonne LS190S models,” says Hickson. “This raises the bar once more in terms of better performance, reduced emissions and lower total cost of ownership.”

Powered by the C7.1 mechanical engine, the new generation LS312 complies with Tier II emission standards while ensuring quieter and more efficient operation.

“Customers’ productivity will benefit from increased engine performance, with 20% higher torque and 8% more power,” he says. “The lower rpm at which the machine can run also translates into less engine wear and lower emission levels.”

Hickson highlights that the new design continues to include a focus on reliability and easier maintenance. The drivetrain has been enhanced with a 12 tonne axle, and the structural integrity of the front frame strengthened. Maintenance crews will have easier access to hydraulic test points, which are now located in a panel on the side of the machine, making for safer working practices. In addition, the improved cooling system will further reduce maintenance time.

The product also offers an optional electronic shutdown system, providing easier fault diagnosis, reducing mean time to repair.

With the industry driven need for collection of machine and operational information, the Sandvik LS312 LHD offers an onboard data monitoring capability allowing for transfer of information via the mine’s Wi-Fi network and management through the “My Sandvik Cloud platform.

“Safety is paramount in all our designs, and a proximity detection interface is now provided as standard,” he says. “The lower frame design – facilitating improved visibility for the operator – has been retained in the LS312.”

The local manufacture of this new model brings a number of benefits to customers and the economy, says Stephan Greisiger, production manager at Sandvik’s world-class manufacturing facility in Jet Park.

“Local production of the LS312 units will significantly reduce the lead-time to our market,” says Greisiger. “This makes it easier for customers to plan capital equipment purchases.”

Sandvik’s quality-accredited facility of some 2,200 m2 under roof ensures the highest standards are applied in the manufacture and assembly of these new units. Its capacity is proven by its output of 5 tonne and 8 tonne loaders.