Increasing energy efficiency of mine ventilation systems

Every year the United States mining industry spends millions of dollars on underground ventilation systems. In the U.S., fan systems used for mine ventilation consume approximately 12,000 million kWh annually (Xenergy, 1997, 1998). Potential motor-driven system energy savings can be realized by using mature, proven, and cost-effective technologies. Such saving potentials exist in the mining industry and the U.S. Department of Energy’s Motor Challenge program aims to assist the industry in capturing them. Energy efficiency upgrades can also achieve significant non-energy benefits such as better equipment reliability, longer equipment life, reduction in maintenance costs and downtime, and an improved working environment. Improved energy efficiency typically leads to reduced environmental emissions. The Motor Challenge program promotes a “Systems Approach ” rather than a “Component Approach ” when evaluating projects for energy efficiency. A systems approach takes into account all the elements from the point the power is distributed into the motor to the actual process work done. Energy saving opportunities exist at all places in the system but not all of them are cost-effective. Depending on the application, these savings can be easily realized by properly sizing and streamlining the fan systems, using premium energy efficient motors, using speed control wherever applicable, defining a proper control strategy and implementing measures that reduce air wastage.