The dust pollution at the fully mechanized heading face has seriously threatened the health of the miners. As the main technical means, the outer spray of a roadheader has the problems of small coverage of the fog field and low dust removal efficiency. Based on the multiscale swirl atomization model of LES-VOF, this study simulated and analyzed the atomization process of the nozzle. The influence law of the diameter, the length and the circulation area ratio of the swirl chamber, and the swirl core angle on the swirl number and atomization effect were determined, and the nonlinear function relationship between variables was obtained. With the help of the BP neural network model, a new type of swirl nozzle is developed which is suitable for the outside spray system at the fully mechanized heading face. The experimental results show that the error between the predicted results of the new swirl nozzle and BP network model is less than 15%, the atomization angle θc is 24.2°, the average particle size D32 is 64.43 µm, and the effective range Reff is about 2.1 m. At the same time, the total dust removal efficiency and respirable dust removal efficiency of the new swirl nozzle at the driver's place are 61.10% and 63.85%, respectively, which are 21.69% and 20.92% higher than the original nozzle.
Keywords: Atomization characteristics; BP neural network; LES-VOF; Multiscale simulation; Pressure-swirl nozzle; Spray.
© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.