Monthly Archives: October 2020

Client Focus

LARGE CUSTOMISED GENSET FOR PLATINUM MINE

Accommodating the space constraints of a South African platinum mining customer, Zest WEG is constructing a large diesel powered generator set to be delivered later this year.

The capacity of the 2,500kVA genset will also make it the largest unit yet to be fully load-tested at the company’s genset manufacturing facility in Cape Town, according to Craig Bouwer, projects and product manager at Zest WEG.

“In addition to functional testing, we will be equipping ourselves to conduct load testing to 11kV on this unit,” says Bouwer. “With load-banks in-house, we will be stepping the voltage down to 400V during the testing, and drawing on MV specialists to ensure a safe and reliable process.”

The genset is a highly technical solution to match the customer’s specific needs, he says. Based on the available space, it is housed within a 12 metre ISO shipping container with the electrically-driven radiator mounted on the roof.

Prime-rated at 11kV and powered by an MTU diesel engine, the genset has been designed in close consultation with the customer over a number of months. Having concluded the engineering design, construction is currently underway in Cape Town. Bouwer highlighted the detailed and time consuming nature of engineering design for a project of this magnitude and complexity.

“Stringent technical requirements demanded lengthy and ongoing collaboration not only with the customer, but between our engineering team and production operations,” he says. “The customer was particularly pleased with our flexibility and the extra effort we applied to ensure the optimal technical returnables for the project.”

As one of the few Original Equipment Manufacturers (OEMs) capable of undertaking a customised genset of this capacity in-house, Zest WEG will also be supplying the control and protection panel from its extensive range of electrical equipment and products.

“To enhance safety and ergonomics, the control panel is in its own compartment within the ISO container,” he says. “A 1,000 litre bunded day tank has also been installed inside a separate compartment within the container, including a fuel cooler and filtration system.”

The Covid-19 lockdown has had minimal impact on the work schedule, he notes, as planning and communication with the customer could continue regardless, dealing with various technical clarifications. To facilitate the transportation of this large unit to site, it will be shipped as three separate components: the genset, radiator and exhaust system. Once installation is complete – a process that Zest WEG specialists will supervise – its experts will conduct the cold and hot commissioning, and hand over to the customer.

Client Focus

BENCHMARK IN COLLISION AVOIDANCE WITH CXS

Supporting mines in their quest for zero-harm, Booyco Electronics’ CXS solution has leveraged technology to achieve new levels of safety in underground and surface mining environments.

“The Booyco CXS solution is engineered to mitigate the risk of collisions between pedestrians and vehicles, or between vehicles, in operational environments,” says Booyco Electronics CEO Anton Lourens. “This system takes the vital step from being just a warning system to becoming a collision avoidance system.”

Lourens highlights that the Booyco CXS is a best-of-breed system that consolidates everything the company has learnt in its 15 years of serving the sector. By upgrading to a new hardware platform, the system’s software updates can be conducted remotely and more frequently – providing increased functionality. It also allows users to comply with the latest and ever more stringent safety regulations.

“Our Booyco CXS is a comprehensive and integrated response to Level 7, Level 8 and Level 9 safety levels – as defined by the Earth Moving Equipment Safety Round Table (EMESRT),” he says.

The new hardware platform is based on principles proven by Booyco Electronics over many years. Technology includes the reliable and accurate Very Low Frequency (VLF) technology for pedestrian detection, and GPS and radio frequency technology for vehicle detection in surface applications.

“At the heart of the system is the Booyco Host Unit (BHU),” Lourens says. “This receives information from the pedestrian sensors, the trackless mining machine (TMM) sensors and the wheeled mobile equipment sensors. It then conducts the necessary proximity calculations and algorithms to alert users to any impending risk scenarios.”

Lourens also emphasises that this BHU integrates seamlessly with original equipment manufacturer (OEM) systems, either directly or through a third-party interface in accordance with ISO 21815.

“This allows the Booyco CXS to apply Level 9 intervention instructions to the machine, as required to for example automatically slowing it down or bringing it to a complete stop,” he says. “Our flexible, comprehensive approach with the Booyco CXS solution has been developed to ensure that all customers can achieve Level 9 compliance, irrespective of the age of their machines.”

Client Focus

TRASH PUMPS IDEAL FOR DIRTY WATER WITH LARGE SOLIDS

Dewatering activities on large construction and infrastructure project sites is not always a simple task. In fact, pumping dirty water containing large amounts of debris calls for a ‘trash pump’, according to Henru Strydom, operations manager at Integrated Pump Rental.

“Contractors often find themselves having to pump water that contains hard and soft solids such as trash, gravel, stones, leaves and twigs,” Strydom says. “In many instances, the construction site needs dewatering to be done at a consistent rate and needs to reduce the chance of a pump clogging with this kind of material. This is why a trash pump is a popular and reliable option, and it offers versatility in terms of its configuration.”

Integrated Pump Rental, with its capacity to design and assembly pump sets in-house, can customise these for the user’s specific site conditions.

“Our comprehensive pump rental fleet  has included trash pumps for some time, and more recently we have been tailor making trash pump sets for customers on request,” Strydom says. “By configuring the pump set to en end-user’s specifications we can ensure the pump dewatering solution is fit-for-purpose.”

The trash pump sets provided by the company are usually trailer-mounted with a diesel engine for optimal mobility, but Strydom says these can also be static units driven by electric motors.

Ensuring proper pump selection means understanding basic requirements like the head height to be pumped, the quantity and flow rate required, and the distance over which the water will be transferred. Trash pumps can typically handle solids up to 76 mm in size with flow rates of up to about 110 litres per second and a maximum head of 32 metres.

“Our self-priming, tried-and-tested trash pumps are often considered as the real workhorses of the construction pump market,” Strydom notes. “Apart from dewatering sites, these can also be easily moved into place where large pipelines have to be temporarily bypassed, for instance, moving large volumes of water quickly and dependably.”

Contractors even use multiple units in remote sites where access is difficult, allowing them to avoid the use of cranes to move and place large single pumping units.

Strydom highlights that Integrated Pump Rental’s in-house experience in designing and assembling trash pump sets also allows it to offer customised service level agreements, based on customers’ preferences and specific conditions. The company’s expertise and service capability mean units can be constantly supported with maintenance, repairs and replacement parts.

Client Focus

DIGITALISING MINERALS PROCESSING FOR MORE CONTROL

Mining’s accelerated move toward digital solutions since the outbreak the Covid-19 pandemic is being supported by FLSmidth’s decades of research and development.

Terence Osborn, FLSmidth’s director of product and account management for sub-Saharan Africa and the Middle East, highlights that R&D is the lifeblood of the company’s new technologies. So much so, that it has some 80 projects underway to improve its mining-related offerings.

“The power of digital technology is certainly a key element of these efforts,” says Osborn. “Together with our Blue Box digital concept, based on our ECS/ControlCenter™, which is a cybersecure interface between our equipment and cloud data storage, we use our SiteConnect™ mobile app to monitor the performance of equipment and process plants in real time. The ECS/ControlCenter™ V8 process control platform sits at the heart of our digital vision, a key component in our growing portfolio of digital solutions and services that we call ENABLR.”

An example of this applied capability is an FLSmidth REFLUX® Classifier modular plant operating on a South African mine. Using SiteConnect, operations managers can have real-time access to over a hundred operational parameters on the plant. Data analytics linked to the cloud data can also generate time-based trends for instant viewing on the app.

“We have also developed SmartCyclone™  technology for our hydrocyclones,” Osborn notes. “This innovation uses sensors to detect wear and roping, a condition that reduces separation efficiency. By sending an alert when certain operating parameters are breached, the system ensures optimal efficiency is maintained, even as slurry conditions in the circuit vary.”

He highlights that the company’s machine-level solutions are offered as part of plant and process  packages. At both plant and process level, there is also FLSmidth’s advanced ECS/ProcessExpert®  solutions, which facilitate not just monitoring and control, but advanced optimisation enabled by state-of-the-art AI technologies.

“It is important to remember that control systems need to be flexible, so that they adapt to customers’ needs and to their existing systems,” he says. “With FLSmidth’s depth of expertise in software engineering and machine control, we can ensure that our machine-level systems connect with all market leading control systems – to seamlessly deliver the data that mines need for effective decision-making.” The company’s R&D pushes the boundaries of performance in a range of mineral processing fields. These include advancing its lamella plate technology in mineral separation applications, adapting its vertical roller mill for dry grinding in mining, and extending wear life of pumps with new polymers.

Client Focus

COAL MINES NEED LOWER COSTS, RAISED PRODUCTIVITY

Despite South Africa’s energy supply being heavily reliant on coal, weak prices and more demanding mining conditions are putting pressure on coal mines and their suppliers to do more with less.

“Coal prices are low and any recovery in the short term is very unlikely,” says Frengelina Mabotja, senior metallurgist and capital sales engineer at vibrating screen specialist Kwatani. “Going forward, as coal seams with more overburden have to be mined, surface mining will potentially become much more expensive.”

Adding to the coal industry’s challenges is the unwillingness of many lenders to fund new coal plants and expansions, leading to great uncertainty. The result is a strong drive for ongoing cost reduction and increased productivity across both majors and juniors in the sector, says Mabotja.

“While most of SA’s coal supply is produced by a handful of major mining houses, Eskom has in recent years sought to develop the junior market with black ownership,” she says. “Kwatani partners with majors and junior miners alike, offering two distinct equipment ranges tailored to each segment’s specific requirements and capital budget.”

With its 44 years of local and global experience, Kwatani provides customised, cost effective processing solutions for mines’ specific needs. She notes that vibrating equipment requirements can vary significantly between a smaller-scale junior miner and a long-life major. This is in terms of the equipment’s size, operating lifespan, tonnage throughput, efficiency and yield requirements.

“Apart from the initial capital expenditure, mines’ process equipment has an enormous influence on their production efficiency, tonnage and operating cost,” she says. “Our long-lasting, robust vibrating screen and feeders are designed for continuous tonnage throughput and high efficiency. This reduces the processing cost per ton and the overall cost of the machine over its lifetime.”

For the large mine segment, Kwatani’s designs have included high capacity and performance screens such as its 4,3 m wide banana screen. Its brute force grizzly feeders for run-of-mine (ROM) operations are capable of sizing and feeding material at up to 2 000 tph, even from high drop-heights.

“Our engineering team has optimised the structural integrity, weight distribution and lifespan of this equipment,” says Mabotja. “We have many of our 4.3m wide banana screens operating at the largest opencast coal complex in the world.”

At the same time, Kwatani supplies screening equipment below 2,4 m wide for smaller-scale, modular plants processing up to 250 tph. These units are tailored to budget and provided within short delivery times.

Client Focus

INTELLIGENT WATER BOOSTING SYSTEMS FOR ENERGY SAVINGS

Ensuring the right pressure and volume of water in a building today calls not just for a reliable system but one that is energy efficient, according to Grundfos external sales representative Nick Pluck.

“Electricity costs are an increasing concern for owners and managers of buildings, and this is from residential and business blocks to hotels and industrial facilities,” says Pluck. “This is where the Grundfos MPC booster systems offer enhanced value.”

Known for their high performance and reliability, the Grundfos Hydro MPC booster systems also offer an advanced, intelligent cascade controller to further improve energy efficiency and ease of operation.

“Over time, the CU 352 smart controller develops its own patterns based on its understanding of a building’s daily requirements,” he explains. “It will register and remember how the water demand changes over the course of a day and ensure the pumps meet that demand without running unnecessarily when demand is low.”

Equipped with this controller, the Grundfos Control MPC can monitor up to six connected identical pumps, each driven by motors with variable speed drives (VSDs).

“We incorporate the VSD so that the controller and MPC can change the speed of each individual motor based on the demand requirement,” he says. “A four-pump system, therefore, could have three pumps running at full capacity while the fourth runs at just 60% – saving energy while still meeting demand.”

As the system’s algorithms calculate patterns, it can trim off waste energy consumption when less pumping is required. The controller can also alternate the starting sequence of the pumps, resulting in more even running time and less wear and tear across the pumps. This allows more accurate and economical service planning and scheduling.

High-efficiency IE3 motors further enhance the Grundfos Hydro MPC’s energy efficiency while maintaining a constant pressure during changing flow demands. With a user-friendly interface, the systems offer ease of installation and commissioning, along with long-term value for money.

Client Focus

DRY TYPE REACTOR FROM TRAFO SAVES POWER FOR SA BANK

When a specialised dry type reactor failed after many years of service in a major banking company’s backup power generating system, Trafo Power Solutions was there to leverage its expertise and applications knowledge.

Trafo Power Solutions supplied and assisted with the installation of a replacement reactor, providing a fit-for-purpose design that accommodated the limited space and awkward position in which the components had to fit.

“The reactor – or inductor – is a key part of the bank’s backup system that feeds a number of buildings in the central business district of Johannesburg,” says Aaron Rost, contracts and proposals engineer at Trafo Power Solutions. “This vital component serves as a link between the utility power, the backup generator and the buildings’ supply.”

Rost explains that the reactor is important for a number of reasons. Among the most important are reducing the bank’s electricity costs, raising the system’s efficiency and contributing to the stability of the municipal power grid.

With its vast data centres, the bank must constantly idle its standby generators online, so that the switchover between utility power and standby power is seamless in the event of a power failure. He notes that to make better use of the fuel consumed by this continuous operation, diesel generators can be repurposed to help alleviate the data centre’s reactive power requirements.

“While active power refers to that element of the power supply that actually does the work – such as driving motors or powering lights – the reactive power is essentially useless power that is being wasted,” he says. “This reactive power effectively draws more current from a grid than what is really required.”

Rost highlights that the reactor stops any of this reactive power from being used from the power grid, This reactor also allows only the active power to be supplied from the grid, and in so doing helps create a more efficient system.

The importance of the reactor’s role in this power system is two-fold, he argues. Firstly, it reduces the bank’s electricity bill, as local municipalities charge a premium rate for the reactive power consumed.

“The reactive power raises the tariff that the client ends up paying at the end of the day,” he says. “By preventing the use of reactive power by the grid, the reactor allows the client to save directly on their overall energy costs.”

The second contribution that the reactor makes is that the local municipality does not have to deal with a ‘troublesome’ load, as this type of loading increases the amount of current being drawn.

“This then leads to additional heating in cables, transformers and switchgear, which erodes the life span of this equipment and can potentially lead to premature failure,” he says. “On a grid which is currently in a fragile state, any failed equipment can have massive implications for the equipment that is attached.”

Rost points out that the reactor also serves as a voltage regulator and filter on the utility power being supplied, allowing a more stable power supply to the building. This delivers a further benefit – in the event of a fault, the reactor can help to limit the fault current, making it less likely that costly utility equipment will be damaged.

Client Focus

DRY TYPE REACTOR FROM TRAFO SAVES POWER FOR SA BANK

When a specialised dry type reactor failed after many years of service in a major banking company’s backup power generating system, Trafo Power Solutions was there to leverage its expertise and applications knowledge.

Trafo Power Solutions supplied and assisted with the installation of a replacement reactor, providing a fit-for-purpose design that accommodated the limited space and awkward position in which the components had to fit.

“The reactor – or inductor – is a key part of the bank’s backup system that feeds a number of buildings in the central business district of Johannesburg,” says Aaron Rost, contracts and proposals engineer at Trafo Power Solutions. “This vital component serves as a link between the utility power, the backup generator and the buildings’ supply.”

Rost explains that the reactor is important for a number of reasons. Among the most important are reducing the bank’s electricity costs, raising the system’s efficiency and contributing to the stability of the municipal power grid.

With its vast data centres, the bank must constantly idle its standby generators online, so that the switchover between utility power and standby power is seamless in the event of a power failure. He notes that to make better use of the fuel consumed by this continuous operation, diesel generators can be repurposed to help alleviate the data centre’s reactive power requirements.

“While active power refers to that element of the power supply that actually does the work – such as driving motors or powering lights – the reactive power is essentially useless power that is being wasted,” he says. “This reactive power effectively draws more current from a grid than what is really required.”

Rost highlights that the reactor stops any of this reactive power from being used from the power grid, This reactor also allows only the active power to be supplied from the grid, and in so doing helps create a more efficient system.

The importance of the reactor’s role in this power system is two-fold, he argues. Firstly, it reduces the bank’s electricity bill, as local municipalities charge a premium rate for the reactive power consumed.

“The reactive power raises the tariff that the client ends up paying at the end of the day,” he says. “By preventing the use of reactive power by the grid, the reactor allows the client to save directly on their overall energy costs.”

The second contribution that the reactor makes is that the local municipality does not have to deal with a ‘troublesome’ load, as this type of loading increases the amount of current being drawn.

“This then leads to additional heating in cables, transformers and switchgear, which erodes the life span of this equipment and can potentially lead to premature failure,” he says. “On a grid which is currently in a fragile state, any failed equipment can have massive implications for the equipment that is attached.”

Rost points out that the reactor also serves as a voltage regulator and filter on the utility power being supplied, allowing a more stable power supply to the building. This delivers a further benefit – in the event of a fault, the reactor can help to limit the fault current, making it less likely that costly utility equipment will be damaged.

Client Focus

BOOSTING SCARCE SKILLS FOR MINING’S MECHANISED FUTURE

Forging 21st century skills to boost productivity in South Africa’s mining sector, Murray & Roberts Cementation has further enhanced its training facilities to develop scarce skills in modern underground mining.

The well-known Murray & Roberts Training Academy (MRTA) at Bentley Park near Carletonville in Gauteng now boasts a specialised Engineering Training Centre for trackless mining machinery (TMM). According to Tony Pretorius, education, training and development (ETD) executive at Murray & Roberts Cementation, the centre will raise skills levels among operators, servicemen, artisans and apprentices.

“As mining becomes more mechanised locally, it is vital that the mining sector keeps up with the technical demands to maintain and repair advanced underground machinery,” says Pretorius. “There are simply not enough suitably trained and experienced artisans to keep the growing number of TMMs well maintained and fully operational.”

He highlights that there was considerable value in upskilling TMM operators to better understand and correctly operate their machines, for instance. This could take some of the pressure off artisans while also ensuring more uptime between equipment servicing.

“Mines aim to raise productivity levels with mechanised mining machinery, and this comes with greater technical demands on mine production and support staff,” he says. “This training will equip artisans with specific skills in mechanised engineering, which are not currently part of the syllabus for conventional trades.”

The centre – which was constructed during the national Covid-19 lockdown at a cost of R1,8 million – includes a workshop, wash bay and refuelling bay with all the necessary tools and infrastructure. It offers training suitable for people undergoing a trade or having completed a trade, introducing them into the wider mechanised mining equipment engineering space.

Pretorius notes that many people remain unemployed after completing their trades at an accredited trade centre; this new centre now enhances their employability while filling an important need in the mining industry’s technology trajectory.

“Here at Bentley Park, we have workplace approval with the Mining Qualifications Authority, authorising us to offer practical training to those undergoing trade training who need workplace experience,” he says. “Our mechanised mining equipment engineering centre can address the workplace learning element of their trade certificate – phase two and phase four of their training.”

The focus is on underground mechanised equipment such as load-haul dumpers (LHDs), roof bolters, drill rigs and utility vehicles. The training incorporates the MRTA’s leading-edge blended training methodologies including e-learning, virtual reality, simulation and workshop practical hands-on training.

“This gives our learners the knowledge, understanding and skills required in mechanised mining equipment engineering,” he says. “In addition to our own employees, we also provide training for the mining sector broadly, and can customise training for mining companies.”

The centre has already enrolled 19 apprentices in the mechanised mining equipment engineering training, and expects considerable interest from the mining industry as a whole. The MRTA is also working closely with the Mining Qualifications Authority to make the training available to qualified work-seekers.

Client Focus

ZEST WEG IN ZIMBABWE ETHANOL EXPANSION

Zest WEG is supplying a TGM planetary gearbox with a WEG variable speed drive (VSD) and a WEG medium voltage motor for a mill expansion by Green Fuel, Zimbabwe’s leading producer of renewable fuel.

According to Leandro Magro, steam turbines manager at Zest WEG, the equipment is destined for the new sugar cane crushing mill #6 at Green Fuel’s state-of-the-art ethanol facility at Chisumbanje in south-eastern Zimbabwe. The plant uses the latest technology to produce high-grade anhydrous ethanol, with a high-pressure boiler and a TGM steam turbine generator set increasing energy recovery. This allows the plant to be self-sufficient in its energy needs, and to generate excess electricity.

Green Fuel’s ethanol project – awarded National Project status by Zimbabwe’s government for its economic contribution – reduces the country’s reliance on imported petroleum products. It also produces less greenhouse gas emissions than unleaded petrol, and can be sold significantly cheaper. The company employs over 3,000 people in its agricultural and industrial operations.

“The engineered gearbox for this project is custom-built by TGM in Brazil, a WEG Group company, and is supplied with a WEG VSD and WEG electric motor as a package,” says Magro. “The components in this solution are designed to deliver the specific torque required to crush the cane to the customer’s specifications – reliably and efficiently.”

The output speed of the gearbox in operation is usually between five and seven revolutions per minute. To deliver the required rotating force, a 750 kW, 3,300 V WEG motor was specified, with a WEG VSD to facilitate speed variations. The volume and quality of cane being brought in from the fields to the mill varies during the harvesting season – usually from April to October or November – so the rate of crushing in the mill needs to be adjustable.

The TGM third-generation planetary gearbox is designed specifically for sugar cane mills, where torque variations are constant and robust construction is required. The bearings are designed to achieve more than 100,000 hours of operation. This means the equipment can run for up to 10 years before any major service intervention is required.

“WEG has supplied efficient and reliable equipment to Green Fuel since the beginning of its operation. During its plant expansion from 2017 to 2018 we supplied a planetary gearbox, motor and VSD for mill number 1,” he says. “Our current contract is for a second expansion, where Zest WEG will supply similar equipment to mill #6.”

While the gearbox is manufactured and assembled in Brazil, the WEG VSD with integral transformer will be assembled in South Africa by Zest WEG. The transformer will step down power from 11kV to the required motor voltage of 3.3kV. Delivery will take place by year-end, although the high efficiency motor will be supplied earlier from WEG in Brazil. Installation of the equipment on site will be conducted in early 2021, over a period of about two weeks. Zest WEG will be involved in the installation supervision and commissioning, which includes the required tests before the start-up.

“We also assist with the start-up of the equipment at the beginning of the crushing season, to ensure that everything is running optimally,” Magro says. “Using several production facilities around the world, Zest WEG provides its customers in Africa an integrated solution that combines the highest quality of equipment with our in-depth industry expertise.”