Characteristics of dust distributions and dust control measures around road-header drivers in mining excavation roadways

Abstract

In the present study, a numerical simulation method was adopted in order to examine the characteristics of dust dispersion during continuous dust release periods (CRP) and stop dust release periods (SRP). The purpose was to analyze the dust distributions and migration actions around road-header drivers in excavation roadways, and then determine effective dust control measures for underground coal mines. This study’s simulation results showed that the dust concentrations continuously increased, and then gradually reached a stability level during the CRP. During that time, the locations of the drivers were always at the intersection of the original migration dust and the backflow dust, and the drivers were invaded by these two strands dust. However, during the SRP, the dust concentrations gradually decreased under the actions of the roadway ventilation. Besides, obvious backflow phenomena were observed around the road-header during the SRP. The locations of the drivers were still within the backflow paths of the high dust concentrations. At the present time, dust separation and extraction systems have been implemented in coal mines, including vacuuming and air knife devices, which are designed to control the dust around the road-header drivers. The field applications of these systems were conducted in the 26 mechanized excavation faces of the Zhangcun Coal Mine. The results revealed that the use of these dust removal systems could effectively reduce the dust concentrations around the road-header drivers. In the present study, the dust removal rates during the CRP and SRP were determined to reach up to 88.7% and 94.6%, respectively. Therefore, the results of this research study provided effective theoretical guidance of the characteristics of dust distributions in coal mines, and introduced effective control methods for the hazardous dust concentrations around road-header drivers during the excavation process.