In-depth survey report: a laboratory evaluation of capture efficiencies of the vacuum cutting system on a Wirtgen W 250 cold milling machine at Payne & Dolan Inc., Racine, Wisconsin.
Hammond D; Trifonoff N; Shulman S
Cincinnati, OH: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, EPHB 282-19a, 2011 Sep; :1-16
In August 2011, NIOSH researchers and the Silica/Milling-Machines Partnership coordinated by the National Asphalt Pavement Association (NAPA) conducted laboratory testing of the Vacuum Cutting System (VCS) on a Wirtgen W 250 cold milling machine. The testing was conducted indoors at a Payne & Dolan, Inc., repair facility in Racine, Wisconsin. All tests were conducted on a stationary machine with the drum spinning and the belts moving but without any reclaimed asphalt pavement moving through the system. The machine was set up to simulate the amount of open area around the drum that would be present during a typical milling job. Smoke and tracer gas were used as surrogates for silica dust to evaluate capture efficiencies of the dust emission-control system in the drum housing of the machine. Smoke was used as an initial qualitative test to visually check for leaks from the drum housing of the machine. Sulfur Hexafluoride (SF6) was used to quantitatively evaluate capture efficiency of tracer gas released in the drum housing of the machine. Five capture efficiency tests were conducted at a single flow rate on the Wirtgen W 250 cold milling machine. The overall mean capture efficiency as measured by the Brüel & Kjær monitor was 92.7% with a lower 95% confidence limit of 92.0%. The overall mean capture efficiency as measured by the Miran SapphIRe monitor was 93.5% with a lower 95% confidence limit of 92.7%. Additional field testing is recommended to verify the laboratory results. The testing reported here only evaluated capture efficiency in the drum housing. Other potential dust release locations on the machine such as the transition between the primary and secondary conveyor and the top of the secondary conveyor were not evaluated during this testing but would be evaluated during field testing.
Control-technology; Engineering-controls; Region-5; Construction; Ventilation; Ventilation-systems; Exhaust-ventilation; Laboratory-testing; Machine-operation; Milling-industry; Construction-equipment; Road-construction; Simulation-methods; Engineering; Equipment-design; Control-equipment; Control-systems; Dust-collection; Dust-control; Dust-control-equipment; Equipment-reliability; Performance-capability; Emission-sources; Testing-equipment; Qualitative-analysis; Quantitative-analysis; Gases; Analytical-instruments; Infrared-spectrophotometry; Vacuum-cleaning-systems; Vacuum-equipment; Testing-equipment
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Field Studies; Control Technology
NTIS Accession No.
National Institute for Occupational Safety and Health