Strike force 2 dust8/10/2023 ![]() ![]() The comparison was made evaluating dust concentrations generated from the drill shroud in the laboratory to those predicted from the simulations. Simulation results were compared with the experimental data for a 0.14-m 3/s (300-cfm) and a 0.24-m 3/s (500-cfm) bailing airflow with 2:1, 3:1 and 4:1 dust collector-to-bailing airflow ratios, having a 5.0-cm (2-in.) gap at the shroud-to-ground interface, which is a commonly encountered gap size for medium-sized rotary blasthole drill. In order to ensure the correctness of the CFD modeling, previously run experiments conducted in the NIOSH full-scale drill shroud laboratory were utilized to validate the CFD models. In order to understand the respirable dust behavior in and around the drill shroud and to develop and evaluate the effectiveness of various control techniques, numerical simulations using computational fluid dynamics (CFD) can be applied to evaluate different scenarios. This study focuses on the drill shroud portion of the dust collector. The exhaust fan on the collector body is used to pull dusty air and material from the drill shroud into the collector housing where it is filtered.Ī basic dry dust collection system on a drill. To summarize the collector operation, compressed air (bailing air) is used to flush the drill cuttings out of the drillhole. Many studies have been completed on dry dust collectors, so a detailed operational description will not be provided here ( Maksimovic and Page, 1985 Bailey and Page, 1987 Organiscak and Page, 1995 Organiscak and Page, 2005 Reed et al., 2008 Potts and Reed, 2008, 2011). Although wet drilling is a better dust control method, it requires a constant water supply, reducing drill bit life through excessive bearing wear and hydrogen embrittlement, and causing freezing-related issues in colder climates.įor medium-sized and large drills, such as the Atlas Copco DM45, Sandvik 460 and Drilteck D45K, a typical dry dust collection system schematic is shown in Fig. Many rotary blasthole drilling operations use a dry collection system ( Cecala et al., 2012). All but one of the nine miners worked at occupations that were in the vicinity of blast-hole drilling, either as a driller, blaster or blast crew member ( Halldin et al., 2015). Twelve miners had radiographic changes consistent with progressive massive fibrosis, and nine of these 12 miners reported no underground mining tenure. Pneumoconiosis was found in 2 percent of the 2,328 screened miners with at least one year of mining tenure. This program offered free chest radiographs to surface coal miners in 16 states. Of significant interest is an X-ray surveillance study recently completed under the National Institute for Occupational Safety and Health (NIOSH) Enhanced Coal Workers’ Health Surveillance Program. 7.5 percent of blasters/shotfirers were overexposed to respirable silica dust (three out of 40 samples). ![]()
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