Acoustic Redesign and Experimental Validation of a Continuous Miner Scrubber Fan System

In the mining industry, noise induced hearing loss affects 90%+of miners. Continuous Miners (CMs) are some of the loudest machines in mining operations. To achieve CM noise reduction, this project addressed the main noise source, the coal dust scrubber system. The goal was to mitigate this source while maintaining required dust collection performance. To this end, a completely new fan system was designed. Some of the changes in the new fan were altering the rotor/stator blade count, increasing the spacing between the rotor and stators, and new blade profiles used for both the rotor and stator. With the fan noise source reduced, inflow interaction noise was predicted to be the next significant source. Ductwork leading to the fan creates significant inflow distortions ingested by the fan. To reduce this source, the ductwork was redesigned to reduce inflow distortion by reshaping the area between the ductwork exit and fan inlet and removing the demister mid span damper, along with other minor changes. Finally, a new acoustic liner was designed to further increase noise reduction levels. A physical new fan prototype with modified ductwork and acoustic liner was manufactured, and 11.9 dB of overall noise reduction from the baseline was measured.