Mining Project: Engineering Noise Controls for Longwall Mining Systems

Research Summary

This project had four research aims, as follows:

1. Identified and ranked dominant noise sources on longwall mining systems, acquired operating data, collected laboratory data, and created computer modeling of noise controls.
2. Developed and evaluated noise controls in the laboratory, refined and re-evaluated modified noise controls using numerical modeling, and installed and evaluated actual noise controls in a working environment.
3. Performed a case study to assess performance and durability of noise controls.
4. Transferred research findings to industry and developed related marketing media.

Approximately 50% of the coal mined in the US is extracted using longwall mining systems. Studies have shown that longwall crews in particular can be potentially overexposed, with sound levels as high as 105 dB(A). Such levels could lead to overexposure and potential hearing loss in as little as one hour.

This project focused on reducing hearing loss of miners working in longwall units. Engineering noise controls were developed to reduce the sound levels generated by longwall mining systems. A novel approach of this project was the use of modeling techniques to understand the vibration and noise radiation of longwall components. Prior to this project, researchers did not have the capability to develop and use numerical models for acoustic prediction in the development of noise controls for longwalls. Because a longwall may be over 1,000 feet long, it was impossible to test the complete systems in NIOSH laboratories. Instead, modeling was used to understand longwall noise sources and to evaluate possible controls.

Laboratory measurements were utilized to evaluate critical components and to validate models. An integral part of this research program involved working with industrial partners to assist in longwall modifications and to facilitate commercialization of the noise controls developed. Specifically, the industrial partners were the manufacturer of the cutting drums and a mine operator where the noise controls were installed for the production of an entire longwall panel. The effectiveness of these noise controls was evaluated in a laboratory setting and in an underground setting where the noise reduction in worker exposure was assessed.

The developed noise controls provided a reduction of approximately 3 dB in the sound pressure level at the operator location and a 61.9% reduction in the operator’s cumulative noise dose during an 8-hour shift.

Related Publications

• H.E. Camargo, D.S. Yantek, and A.K. Smith, “Development of a validated finite element model of a longwall cutting drum,” Proceedings of InterNoise, New York (2012).
• J. Yang, H.E. Camargo, and D.S. Yantek, “Sound Radiation Modeling and Correlation of a Longwall Cutting Drum,” Proceedings of NoiseCon, Denver, Colorado, USA (2013).
• H.E. Camargo, G. Gwaltney, and L. Alcorn, “Development of an Instrumented Longwall Bit to Measure Coal Cutting Forces for Use in Developing Noise Controls,” Mining Engineering, 2015, Vol. 67, No. 5, pp. 57-62.
• J. Yang, H.E. Camargo, and D.S. Yantek, “Sound Radiation Analysis of a Longwall Cutting Drum,” ASME IMECE, San Diego, CA, USA (2013).
• J. Yang, H.E. Camargo, and D.S. Yantek, “Noise control concepts for a longwall cutting drum,” Proceedings of NOISE-CON 2014, Fort Lauderdale, FL, September 8-10, (2014).
• H.E. Camargo, M. Li, and L.A. Alcorn, “Comparison of Numerical and Experimental Results of Noise Controls for a Longwall Shearer Drum,” Proceedings of InterNoise 2015, San Francisco, CA, Aug. 9-12, (2015).
• H.E. Camargo, and L.A. Alcorn, “Evaluation of Noise Controls for Longwall Cutting Drums,” Proceedings of NoiseCon 2016, Providence, RI, June 13-15, (2016).
• H.E. Camargo, A.S. Azman, and L A. Alcorn, “Development of Noise Controls for Longwall Shearer Cutting Drums,” Noise Control Engineering Journal (NCEJ), 64(5), September-October (2016).

Related Patent

• “Cutter Head for Longwall Shearer,” US 2016/0102549, April 14, 2016.