Mining Publication: Laboratory Evaluation of a Canopy Air Curtain for Controlling Occupational Exposures of Roof Bolters
Original creation date: June 2001
Authors: GV Goodman, JA Organiscak
NIOSHTIC2 Number: 20021319
Proceedings of the Seventh International Mine Ventilation Congress, June 17-22, 2001, Crakow, Poland. S Wasilewski, ed., Crakow, Poland: Research & Development Center for Electrical Engineering and Automation in Mining (EMAG), 2001 Jun; :299-305
In the United States, respirable coal mine dust exposures are limited to a 2 mg/m3 time weighted average for a working shift. If the silica content of the sample exceeds 5 percent, the 2 mg/m3 standard is reduced according to 10 ) (% silica) to limit silica dust exposures to 100 µg/m3. Examinations of dust sampling data collected by the federal coal mine inspectorate showed that roof bolter occupations continue to be at risk for overexposure to respirable silica dust. Testing at the Pittsburgh Research Laboratory of the National Institute for Occupational Safety and Health assessed the effectiveness of a canopy air curtain for controlling occupational exposures to respirable silica and coal dusts. Initial testing found that zones of higher velocity airflow shrank as distance beneath the canopy increased. This suggested that protection from occupational dust exposures would likely decrease as distance beneath the canopy increased. Further testing revealed that coal dust reduction efficiencies were most affected by changes in interference air velocity and, to a lesser extent, changes in canopy air quantity. However, respirable silica dust percentages under the canopy were not affected by such changes and, in fact, were not significantly different from silica percentages measured outside the canopy. This implied that the air curtain was equally effective on both respirable coal and respirable silica dust particles.

NIOSHTIC2 Number: 20021319
Proceedings of the Seventh International Mine Ventilation Congress, June 17-22, 2001, Crakow, Poland. S Wasilewski, ed., Crakow, Poland: Research & Development Center for Electrical Engineering and Automation in Mining (EMAG), 2001 Jun; :299-305
- Control of Respirable Dust
- Development of a canopy air curtain to reduce roof bolters' dust exposure
- Development of a Roof Bolter Canopy Air Curtain for Respirable Dust Control
- Evaluating Portable Infrared Spectrometers for Measuring the Silica Content of Coal Dust
- An Evaluation of Methods for Controlling Silica Dust Exposures on Roof Bolters
- Evaluation of the Approach to Respirable Quartz Exposure Control in U.S. Coal Mines
- Field Comparison of a Roof Bolter Dry Dust Collection System with an Original Designed Wet Collection System for Dust Control
- A Field Study of a Roof Bolter Canopy Air Curtain (2nd Generation) for Respirable Coal Mine Dust Control
- Improving Silica Dust Control Through Targeted Research
- Respirable Quartz Hazard Associated with Coal Mine Roof Bolter Dust