Field and laboratory evaluation of sintered metal diesel filtration system
By Aleksandar D. Bugarski1, Emanuele Cauda1, Jon Hummer1, Larry Patts1, and Jozef Stachulak2
1 National Institute for Occupational Safety and Health, Office of Mine Safety and Health Research, Pittsburgh, PA 15236, U.S.A
2 Vale, 18 Rink Street, Copper Cliff, Ontario, POM 1NO Canada
A series of laboratory and field evaluations were conducted in order to characterize the effects of a sintered metal filtration (SMF) system on the aerosols and criteria gases emitted by diesel engines. The SMF system uses a durable sintered metal filter media and the regeneration of the filter is carried out by an on-board electrical heater and is supported by iron-based fuel additives. These features make this system suitable for retrofitting diesel engines used in light and medium-duty mining applications. The system evaluated in this study was installed on a locomotive from the underground mining fleet at the Vale Creighton Mine and operated for over 750 hours prior to testing. In-situ testing and laboratory evaluations were performed at the Creighton Mine surface shop and at the diesel laboratory at the National Institute for Occupational Safety and Health (NIOSH), respectively. At the Creighton Mine surface shop, the system was evaluated when the engine was operated under hydraulic stall, high idle, and low idle conditions. At the NIOSH laboratory, the system was evaluated by maintaining the engine at four steady-state conditions as well as a custom designed transient cycle. Measurements in the diesel exhaust, both upstream and downstream of the SMF system, were performed in order to assess the effects of the system on emissions. To perform the aerosols analysis, a sample from the exhaust was continuously extracted and diluted by a two-stage partial flow dilution system. A fast mobility particle sizer spectrometer and a scanning mobility particle sizer spectrometer were used to measure the number concentration and the size distribution of the aerosols. During the laboratory study, aerosol samples were collected on quartz fiber filters and analyzed via NIOSH method 5040 for the measurement of elemental carbon. The concentrations of CO, CO2, NO, and NO2 were measured directly in the engine’s exhaust using a Fourier transform infrared spectrometer. Both field and laboratory evaluations showed that the system is very effective in reducing aerosol emissions from tested engines. The system was found to have minor effects on gaseous emissions. The findings from this study should help the mining industry to better understand the benefits and challenges of using sintered metal filtration systems to control the exposure of underground miners to diesel aerosols and gases.