Horizontal vibrating screen noise in coal preparation plants, dominant noise sources, and noise controls.
International Coal Prep 2012: Proceedings of the Annual Coal Processing Exhibition and Conference, April 30 - May 3, 2012, Lexington, Kentucky. NY: Penton Business Media, 2012 Apr; :1-17
Sound levels in coal preparation plants often exceed 90 dB(A) and workers who spend a significant portion of their work shift in a preparation plant can be overexposed to noise. The National Institute for Occupational Safety and Health (NIOSH) Office of Mine Safety and Health Research (OMSHR) has studied horizontal vibrating screens as a noise source in coal preparation plants. Contour maps of the in-plant sound levels show that vibrating screens are a significant noise source within the plants. In use, the sound levels round vibrating screens often exceed 95 dB(A). NIOSH OMSHR determined that the majority of the noise generated by screens during their operation is due to drive noise rather than material flow. In laboratory testing, NIOSH OMSHR identified the screen body, vibration mechanism housings, and steel coil springs as the most significant sources of screen noise using a technique known as beam forming. Several trial noise controls were developed and tested to address each of these noise sources. Laboratory measurements in the NIOSH OMSHR reverberation chamber show that installing a mechanism enclosure, applying constrained layer damping treatments to the mechanism housings, installing a mechanism suspension, and inserting elastomeric spacers between the steel coil springs reduced the sound power level generated by 6 dB(A).
Mineral-processing; Coal-processing; Noise; Noise-exposure; Noise-sources; Noise-control; Sound; Vibration; Control-technology; Engineering-controls
International Coal Prep 2012: Proceedings of the Annual Coal Processing Exhibition and Conference, April 30 - May 3, 2012, Lexington, Kentucky