Optimizing parameters for cyclic negative pressure dust suppression devices for roadheaders

Effectively managing dust in the advancing headings of coal mines is essential for ensuring underground operational safety. Traditional dust suppression methods, such as spraying, are relatively inefficient in high-concentration dust environment during excavation operations. This study therefore introduces a cyclic negative pressure dust suppression device for roadheaders via synergistic enhancement of negative pressure suction and spray dust suppression. We set up a simulation model for numerical simulation on the influencing factors of jet stream suction mechanisms. We optimized the parameters, including the shape of injection nozzle, blade configuration, and the number of Venturi tubes, based on the variation rules of the negative pressure flow field both inside and outside the device. Similarity experiments were also conducted to validate dust suppression efficiency of the optimized device based on its variation patterns in internal and external cyclic negative pressure flow field. Results indicate that under constant spraying conditions, the device exhibited optimal performance in terms of cyclic negative pressure with a conical nozzle, 8 blades, a blade speed of 2 400 rpm, 10 Venturi tubes, and a blade installation 300 mm from the nozzle inlet, resulting in a dust suppression efficiency of up to 87.4% in the similar model.