MechChem Africa November-December 2020

⎪ Minerals processing and materials handling ⎪

A uniquely controlled mechanical skew limitation makes sure that damage cannot occur while enabling enough skew to promote grinding uniformity.

pressure while raising the effective crushing area, hence the rolls can process more feed using less energy,” he explains. “And rotating plates can be retrofitted to any of our legacy HPGRs,” VanWyk adds. “As with all of our HPGR Pro innovations, they have been designed as potential add-ons to installed units. By just adding rotating plates, existing thyssenkrupp HPGRs can either be set up to producemore downstreammaterial of the same cut size or to run at the same feed rate with a finer cut size,” he notes. In terms of wear life, the uniform pres- sure profile in the milling gap results in bet - ter grinding and more even roll wear. This prolongs the service life of the rolls by up to 30%. “The rotating plate design with lower peak pressure reduces the ‘bathtub effect’ on the rolls, which enables them to be replaced less frequently. So the HPGR Pro can run for longer with less downtime,” he explains While many believe that roller skew should be completely prevented, Van Wyk argues that a certain amount of skew is beneficial, because it ensures uniform grinding. “A small and limited amount of skewing enables the HPGR to compensate for different nip-in conditions on either side of the rolls, due to feed segregation, for example,” he explains. “The new and uniquely controlled me- chanical skew limitation built into the HPGR Pro allows skewbut prevents excessive skew, making sure that damage cannot occur while enabling enough skew to promote grinding uniformity,” he says. The skew limiting device also prevents excessive forces going through the bearings, which can easily occur when skewing is suppressed. Controlled mechanical skew limitation for greater safety

and filtration system. High tem - peratures during highermachine usage periods can therefore be avoided and the oil circulation system supports easier cleaning.

Pro’s operation and to optimise throughput, energy consump- tion or machine availability in line with specific targets. This transparencyenables fast diagno-

sis and root causeanalysis,” saysVanWyk. In summary, he notes that the new thys- senkrupp HPGR Pro is: • More efficient than ever: It offers best possible grinding outcomes with up to 20% more throughput thanks to opti- mised material feed and reduced wear and tear. • More reliable than ever: It delivers higher machine availability through increased transparency on roller status, predictivemaintenanceofmachinecom- ponentssuchasbearings,combinedwith fast, professional service at any location worldwide. • More high-end than ever: State-of-the- art sensor technology and data analysis gives greater transparency and ongoing optimisation, resulting in an even better performance and higher productiv- ity through continual roller monitoring while the machine is in operation. Concluding, he reminds us that all of the new HPGR Pro features can be retrofitted to thyssenkrupp legacy units, and customers may pick and choose which combination of upgrades best suits their needs. “Customers andHPGR operators can rely on our full support in equipping existing ma- chineswith the latest technical features from the HPGR Pro, making machines that are fit for the future. Through our local network of service centres and specialists, thyssenkrupp is able to offer rapid support, wherever and whenever it is needed,” VanWyk assures. q

Optimised bearing seals, oil quality moni- toring and continual filtering also reduce contamination and allow the oil to be used for longer, reducing costs and environmental impacts. Laser-based stud damage detection “The availability of theHPGRPro is increased even further through our unique stud detec- tion system. While the machine is operating, the surface of the rolls is automaticallymoni- tored and measured by a laser, constantly informing the operator about the state of the studs and the rolls,” VanWyk continues. The stud detection system is used to predict the best possible time for roller re- placement. “And there is no longer a need to routinely stop themachine for precautionary inspections, which saves valuable time and money.” Analytics and machine learning Continual optimisation via data analysis has been incorporated into the thyssenkrupp HPGRPro by addingmodern sensor technol- ogy and an Advanced Machine Protection System. “Basedonour specialist expertise, we areable tousedata collected toautomatically ensure that any installed HPGR Pro runs at its optimum operating point. This prevents overloading and vibrations, and ensures production is optimised. “What’smore,ourglobalspecialistscollect and process the machine data to enable us to continuously improve a particular HPGR

Oil lubrication for increased availability

With theHPGRPro, the roll bearings are now being lubricated with oil instead of grease. This enables better control of temperatures, since the oil can be circulated through the bearings and back through an oil cooling

Left: Some key innovations incorporated into the new thyssenkrupp HPGR Pro include rotating side plates; controlled skew limitation; oil-based bearing lubrication; laser-based stud damage detection; smart analytics and machine learning. Right: Rotating side plates reduce peak central pressure while raising the effective crushing area.

November-December 2020 • MechChem Africa ¦ 7