The development and application of a novel multi-radial-vortex-based ventilation system for dust removal in a fully mechanized tunnelling face

[Display omitted] •The mechanism of multi-radial-vortex-based dust purification was analyzed.•Simulation experiment results of multi-radial vortex airflow was analyzed.•A novel ventilation system for dust removal was developed. In order to enhance the dust removal rate on fully mechanized tunnelling face, a novel multi-radial-vortex-based ventilation system was developed. A detailed analysis of functional principle was carried out. Numerical simulation was conducted to assess the formation of multi-radial-vortex flow pattern and the associated purification performance. The results indicate that a multi-radial vortex covering the entire tunnel cross-section is formed, and a dust-control air curtain is developed as in response to the air suction. It is further established that by decreasing the inflow-to-outflow ratio of air, the uniformity of flow velocity within the dust-control air curtain is enhanced, and the dust diffusion distance and its concentration at the operating location are reduced. Field test of the currently developed method at the 3down610 fully mechanized tunnelling face indicates that the application of the current method based on an inflow-to-outflow ratio of 0.75 leads to the dust reduction of 82.93% compared with the case in which the generator is switched off. The results demonstrate the outstanding performance of fully-enclosed dust removal and air purification.