Numerical study of gas-solid two-phase flow around road-header drivers in a fully mechanized excavation face

摘要

It is known that high-concentrations of dust threaten the health of road-header drivers in fully mechanized excavation faces. The regulation of the gas-solid two-phase flow in fully mechanized excavation faces is a key scientific issue for dust prevention and treatment. In this research study, a real fully mechanized excavation face was taken as the physical model. Then, a CFD-DPM method was adopted to model the gas-particle two-phase flow around a driver in a mine roadway. The results showed that there were two counter directional airflow paths on the heading face which formed three vortices, the centers of which were located in the front left, left and middle sections of the road-header, respectively, in the fully mechanized excavation face. The driver was located at the intersection of the three airflow paths. For example, the position of the driver was within the vortices from the left, front-right and rear of the road-header, respectively. The aforementioned airflows carried dust to the space around the driver through three path types including from the heading face, along the roadway floor left of the road-header, and by refluxing from the rear of the road-header. The dust concentration in front of the driver was observed to increase with a fluctuating growth trend. Also, the dust concentraion to the rear of the driver displayed stepped increases. Finally, the dust concentration which had refluxed from the rear of the driver was determined to be highest and was observed to be three times higher than the dust concentration which originated from the heading face. This study's simulation results were verified by the results of the field measurements. (C) 2018 Elsevier B.V. All rights reserved.