The effects of the installation position of a multi-radial swirling air-curtain generator on dust diffusion and pollution rules in a fully-mechanized excavation face: A case study

A great number of dusts are produced in the fully-mechanized excavation face during coal-cutting process. In order to block the dusts within the unmanned operating zone in front of the roadheader driver, this study combined FLUENT numerical simulation and field measurement for examining the dust's diffusion and pollution rules when both multi-radial swirling air-curtain generator and wet dust removal fan were used in the fully-mechanized excavation face; moreover, dust suppression performances when the generator was 5-50 m away from the head-on section (i.e., L-g) in the excavation face were investigated in depth. According to numerical simulation results, when L-g was 5-20 m, the diffusion distance of high-concentration dusts (with a concentration over 10 mg/m(3)) first increased and then decreased as the generator moved further away from the head-on section; when L-g was 14.8 m, dust pollution and diffusion were most serious; When L-g was 30.3-38.4 m, dust was diffused to the back of the roadheader driver, i.e., dust's diffusion and pollution cannot be effectively blocked in head-on region; When L-g was 20-30.3 m and L-g was 38.4 m, the generated dusts in coal cutting were significantly blocked within the range 5.88 m away from the head-on section, thereby exhibiting favorable dust-suppression performances; in particular, when L-g was 25 m, optimal dust-suppression performance can be obtained. Finally, the accuracy of the present numerical simulation results was validated by field measurement results. (C) 2017 Elsevier B.V. All rights reserved.