By Shelley Gager and Matthew Rodebush
As society continues to become more urbanized, and as it progresses in a shift toward electric transportation, it will eventually come to rely on minerals and metals more than ever before. Industrial electric motors provide the motion that keeps those vital materials moving – about 70% of the electricity used in industrial applications is used to power the millions of industrial electric motor systems around the world. In the mining industry alone, there are hundreds of motor-driven applications that depend on motors that are reliable, durable, safe and efficient.
Mining and aggregate production places demand on all equipment; motors used in these applications must be built to withstand the harshest conditions imaginable. While durability and ease of maintenance continue to be of concern for motor operators, specifying engineers are increasingly turning their focus towards energy efficiency and cost savings. Newer, modern motors are more efficient than motors manufactured even a few years ago. However, there are additional approaches to increasing whole-system efficiency while optimizing equipment control, one of which is pairing motors with variable-speed drives.
The basic function of a drive is to control the flow of energy from the power supply to the motor, thus controlling the motor’s speed, power and torque output. It does this by converting the incoming fixed AC voltage and frequency into DC voltage and then back to an AC voltage at a specific voltage and frequency. A drive allows for smooth starting, acceleration and deceleration of the motor which is highly beneficial to the constant-torque applications prevalent in the mining, aggregate and cement industries.
Much of the function of motors in use in the mining industry is that of moving material, often done by conveyors – a constant-torque application. Other examples of constant-torque applications are cranes, hoists, extruders, mixers, positive-displacement pumps, reciprocating air compressors and rotary screw air compressors. Constant-torque applications require the same amount of torque throughout a specific speed range. Whether these conveyors run at a single operating speed or require adjusting to maximize production, inverter-duty motors are designed and manufactured to operate at reduced speeds and not overheat when run with a drive.
In addition to providing optimum performance for constant-torque applications, pairing an inverter duty motor with a drive offers additional benefits, such as soft-starting capabilities and generally smoother operation to protect belts and other equipment, which lead to reduced maintenance costs and downtime and longer motor and equipment life.
Obviously, improving motor-driven equipment performance, reliability, safety and efficiency are top priorities for mining operations, but there is also a need to predict potential issues before they happen to prevent unplanned downtime. Modern monitoring solutions harness the power of digitalization to put real-time data at the operator’s fingertips. These systems combine connectivity and data analytics with expert advice from real people to provide deeper insight into the health of the entire process enabling safer, smarter and more sustainable operations.
The global mining industry must navigate a multitude of megatrends. Minerals and metals are essential in the transition towards net zero as clean energy technologies increasingly require more significant quantities of minerals than fuel-based solutions. The mining industry can take steps to improve energy efficiency, productivity and reduce emissions by using well-established technology, such as variable speed drives paired with high-efficiency industrial electric motors, which can optimize productivity, reduce unnecessary costs, and maximize equipment availability to ensure we have a bright and sustainable future.
Shelley Gager is director, integrated motor drives for ABB; and Matthew Rodebush is the global segment manager for NEMA motors, at ABB.