... of fans, pumps, compressors, mills, conveyors and lifts 1. Variable Frequency Drive characteristicsVFD is a masterpiece of outstanding ... torque impulse is less than 0.1%, which greatly reduce the resonance of the fan. VFD has frequency-skipping function ... . Cement: Pre-heater fan, Coal mill fan, Cement mill fan, Bag house fan, Raw mill fan, Lignite Mill Filter Fan, By Pass Filter Fan, Kiln. Mining: ...