Rock Products

JUN 2019

Rock Products is the aggregates industry's leading source for market analysis and technology solutions, delivering critical content focusing on aggregates-processing equipment; operational efficiencies; management best practices; comprehensive market

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Page 47 of 91

46 • ROCKproducts • June 2019 EQUIPMENT & TECHNOLOGY PUMPS & MOTORS Netzsch Pumps North America and its German headquarters Netzsch Pumps & Systems announced the availability of safe, reliable and cost-efficient mine dewatering pumps and pump skids ideal for mines that require a small and compact movable unit to address their dewatering challenges. Also available for mining applications are Nemo progressive cavity pumps and the self-priming, valve-less Tornado T2 positive displacement pump. The base mine dewatering pump skid unit includes a tank, progressing cavity pump with right angle gear motor, inspection ladder, valves and piping – all mounted on a common galvanized steel skid. Also available are optional units with a control panel (with or without VFD on a removable stand) and instrumentation, including high/low level switches for the tank or dry run protection for the pump. Individual pumps are available to retrofit existing skids. The tank includes baffle/divider screens to filter out any solids too big to fit through the pump. The pump is located to the side of the tank, enabling easier access and maintenance. The standard unit uses a right angle gearmotor to save space and eliminate the need for a belt drive, but belt and pulley designs are also available. Oper- ator safety is enhanced by the inclusion of a removable inspection ladder with handrails and a removable safety screen for the tank. Netzsch, Van der Graaf (VDG) Drum Motor Consumes Less Energy Conveyor users and conveyor manufacturers have accepted the drum motor as the most efficient way to drive belt con- veyors. With no external motor and gearbox, the drum motor saves space, eliminates the need for scheduled maintenance and enhances operator safety. However, the challenge has been the ease and ability to adjust belt speed as plant processing requirements change. This is achieved via a frequency inverter (VFD), which often is located in a control room some distance away from the con- veyor drive electric motor. The long cable connecting the VFD to the electric motor can impede motor performance and substantially reduce its life and reliability. Voltage attenuation, due to the long cable length, contributes to inconsistent power being delivered to the motor. Resulting high-voltage electrical spikes amplifica- tion in the motor windings can cause complete motor failure. The general approach to overcome these issues is to sub- stantially increase the dielectric strength value of the magnet wire used in the electric motor windings. Sinusoidal filters also are installed to condition the power going to the motor and filter high-voltage spikes caused by the pulse-simulated sine wave of the VFD. Recently, Van der Graaf (VDG) began developing an advanced drum motor design with the VFD integrated into the motor junction box. The follow-up design to the built-in VFD is the development of an electric motor with even higher efficiency and additional capabilities. On a standard electric motor, the rotor has to be magnetically induced by the stator. Using part of the magnetization pro- duced by the stator windings to magnetically induce the rotor results in significant magnetic energy losses and reduces mechanical output. As a result, motor efficiency decreases. With the VDG Intelligent Drum Motor (IntelliDrive) design, the rotor is magnetically self-induced by the use of perma- nent magnets installed on the rotor body. Lab test results show electrical savings of up to 72% vs. a conventional motor/gearbox conveyor drive. The IntelliDrive requires a sensorless vector control to operate, and due to this requirement, must be used with the integrated VFD. The integrated VFD is EtherNet/IP and MODBUS compatible and enables communication with other plant equipment. It also can provide conveyor drive data feedback and control belt speed either remotely or directly at the drum motor. The combination of the rotor with per- manent magnets and the integrated VFD, distinguishes the IntelliDrive from a standard drum motor. The IntelliDrive simplifies the selection of belt speed without loss of torque or belt-pull, substantially increasing the effi- ciency and the life of the electric motor, further minimizing downtime and decreasing overall operating costs. The inno- vation is best for portable plants, according to VDG. Van der Graaf (VDG), Netzsch Mine Dewatering Pumps are Cost Effective

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