Effects of forced-air volume and suction region on the migration and dust suppression of air curtain during fully mechanized tunneling process

To grasp the effects of forced-air volume and suction region on the migration and dust suppression of air curtain during fully mechanized tunneling process, the 1:1 proportional physical models of the 2-508(2) fully mechanized tunnel were constructed, the CFD-DPM based numerical simulations were conducted. The results showed that during the migration process of the air curtain, the decrease of the forced-air volume and the arrangement of the suction region near the side wall opposite to the forced-air duct were conducive to the formation of a uniformly distributed axial airflow region. At the same time, the dust pollution area satisfied the rule of reducing with the decrease of the forced-air volume as well. When the forced-air volume was 350 m(3)/min and the suction region was near the side wall opposite to the forced-air duct, the diffusion distance of high concentration dust reached to the minimum, the dust concentration at the place that the tunneling driver located had fallen below 50 mg/m(3), the best dust suppression performance could be achieved. The model effectiveness was finally validated by comparing the simulation results with the field measured values. This study could provide new insights into the environmental sustainability of tunneling process. The achievements could meet the requirements of process safety and environmental protection in fully mechanized tunnels. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.