DPM simulation in an underground entry: Comparison between particle and species models

The diesel particulate matter(DPM) emission from diesel powered equipment in underground mines can cause health hazards including cancer to the miners. The understanding of the DPM propagation pattern under realistic mining condition is required for selecting proper DPM control strategies and to improve working practices in underground mines. In this paper, three dimensional simulations of DPM emission from the exhaust tail pipe of a load-haul-dump(LHD) vehicle and its subsequent distribution inside an isolated zone in the typical underground mine are carried out using two different solution models available in Ansys Fluent. The incoming fresh air into the isolated zone is treated as a continuous phase and DPM is treated either as a continuous phase(gas) or as a secondary discrete phase(particle). Species transport model is used when DPM is treated as gas and discrete phase model is used when DPM is assumed to behave like a particle. The distributions of DPM concentration inside the isolated zone obtained from each method are presented and compared. From the comparison results, an accurate and economical solution technique for DPM evaluation can be selected.

Effect of single dead end entry inclination on DPM plume dispersion

Diesel particulate matter(DPM) is a by-product from operating diesel engines. Since diesel powers are one of the major sources of energy for mobile underground mining equipment, the adverse health effects of DPM are of a great concern. This paper used computational fluid dynamics(CFD) method to study the effect of entry inclination on DPM plume distribution in a dead end entry. An upward mining face and a downward mining face were built with a truck and a loader in loading operation close to the face area. A species transport model with incorporated buoyancy effect was used to examine the DPM dispersion pattern for the above steady-state scenarios. High DPM and temperature regions were identified for the two different faces. The model was used to assess the role of auxiliary ventilation in reducing DPM exposures of underground miners working in those entries. In this study, it is suggested to provide local ventilation at least three times of the diesel exhaust rate to be able to lower the average DPM level for the mining upward face. The requirement for local ventilation is much less for the mining downward face. This can provide guidelines for good working practices and selection of diesel emission reduction technologies underground.

The impacts of MINER Act of 2006 on the U.S.mining industry

Several high-profile coal mining accidents since 2006 that killed 27 coal miners have prompted the passing of the Mine Improvement and New Emergency Response Act of 2006 (MINER Act) which was signed into law in 2006,and the proposed S-MINER Act of 2007,which passed the House of Representative in early 2008.The four coal mining accidents are described that are believed to be responsible for both the MINER Act and proposed S-MINER Act,and their potential impacts on the U.S.mining industry.