Engineering & Mining Journal

APR 2018

Engineering and Mining Journal - Whether the market is copper, gold, nickel, iron ore, lead/zinc, PGM, diamonds or other commodities, E&MJ takes the lead in projecting trends, following development and reporting on the most efficient operating pr

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MOTORS AND DRIVES APRIL 2018 • E&MJ 65 manufacturers also have introduced new motor configurations aimed at meeting specific mine-application demands. One example of this trend comes from Nidec, which pointed out that the use of inverters in mine pumping applications has increased dramatically over the past few years. The combination of an inverter and induction motor with a pump produc- es an economical variable-speed drive system that has the potential to provide energy savings and process optimization, according to the company. It may also lead to improved system reliability. Responding to rising demand for vari- able speed motors in industrial appli- cations, in October 2017, Nidec added U.S. Motors brand vertical totally en- closed fan cooled (TEFC) inverter duty motors to its stocked offerings. These ver- tical HOLLOSHAFT high-thrust motors, for use on turbine, mix flow and propeller pumps, range from 5 hp to 300 hp, and are suitable for variable frequency drive (VFD) operation per NEMA standards. The HOLLOSHAFT motor was devel- oped to meet the specific needs of the vertical turbine pump industry. The pump shaft is extended through the hollow shaft, so adjustments required to lift im- pellers and give a running clearance with the pump casing, can be made by a nut threaded on the shaft at the accessible top portion of the motor. On a broader scale, innovations in sensor, communication and analytical technologies, combined with their sub- sequent cost reductions, are leading to an increased demand for remote wire- less condition monitoring solutions in a wide array of industries. These include metals and mining, according to Thomas Schardt, Nidec's senior director of IoT. "End users expect access to real-time data at a much lower cost compared to traditional route-based monitoring. We recognize an increasing demand in the manufacturing industry to monitor and assess machine health condition in or- der to avoid unexpected downtimes and loss of production time," said Schardt. "There is a global trend for companies to use IoT to gather real-time data and achieve quantifiable results that deliver better performance and cost savings. Our solution is based on simplicity, reliability, connectivity and diagnostic intelligence." Nidec's solution is FORECYTE, a stand-alone remote monitoring plat- form introduced last year that uses bat- tery-powered wireless sensors to measure equipment vibration and temperature. FORECYTE collects continuous, real-time data, and visualizes deteriorating equip- ment health. The data is sent wirelessly from the sensor to a gateway and from there through either Ethernet, Wi-Fi or cellular to a cloud portal where it is ag- gregated, stored, analyzed and visualized using a web interface. Data can be ac- cessed at anytime from anywhere using a browser on a web-enabled device. According to Nidec, this advanced form of monitoring offers more value when predictive analytics are added to the equation. Using algorithms, the data collected through monitoring can be mod- eled to identify patterns that help users not only intervene on imminent break- downs, but predict future behaviors and events. Additional sensors and analytics currently being developed, said Nidec, will empower end-users to make smart- er, performance-based equipment deci- sions, ultimately leading to lower oper- ating costs and longer equipment service life. The platform is scalable and has the capability to be integrated with existing supervisory control and data acquisition (SCADA) and legacy systems. Motors Save Megawatts In regions such as Africa, where electrical power can be unreliable, of poor quality and/or prohibitively expensive, modern high-efficiency motors can help cut ener- gy bills and maintenance. Zest WEG, an Africa-based subsidiary of Brazilian elec- trical equipment manufacturer WEG, is taking aim at that market. Almost two-thirds of the power con- sumed by the mining sector is associat- ed with electric motors, so these items of equipment are important for mines to look at when demanding savings, according to Zest WEG Group's African business development executive, Edson Cristofolini. "Where an old 55-kW motor is oper- ating 24 hours a day and seven days a week, we estimate that a mine can save over 20 MW a year by replacing it with a new WEG Top Premium Efficiency IE3 motor," said Cristofolini. These savings add up when consid- ering how many motors are operational on a large mine, he pointed out, also noting that apart from reducing ener- gy consumption, the WEG motors also contribute to mine profitability through a combination of long life, low mainte- nance and reliability. "Repairs and replacements are es- pecially costly and time consuming for mines in remote locations, so these mo- tors are designed to operate reliably un- der harsh operating conditions," he said. "An important aspect of the design in the WEG Top Premium Efficiency IE3 range, for instance, is the class H Insulation with class B temperature rise." This provides a buffer of 60°C between the motor windings' average operating temperature and the actual motor insulation capability, protecting the motor where quality of power var- ies or where ambient temperatures are very high. The motors' design also provides a ser- vice factor of 1.15, allowing a motor to be overloaded by up to 15% continuously without compromising reliability, accord- ing to WEG. With the lower losses and the reduced operating temperature of these high efficiency motors, bearing tempera- tures are also lower. "Lower bearing temperature means that less grease is used, and the intervals between the re-greasing of bearings are longer," said Cristofolini. Nidec's TEFC inverter duty motors are designed specifically to meet the needs of vertical turbine shaft applications.

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