Study on the transport and deposition of micron-sized particles with different densities in the coal mine environment in miners

Abstract

To address the health problems caused by the long-term intrusion of high-concentration dust generated in coal mining operations into the human respiratory tract, this study reconstructed a 3D digital model of the upper airway based on fine industrial CT scanning images, and established the micron particle migration calculation model by Euler-Lagrange method. The transport and deposition mechanisms of dust with different densities under different inspiratory intensities were simulated and analyzed. The simulated results were compared with the results of dust exposure experiments in the upper airway combined with 3D printing technology, and the relative errors obtained were in the range of 2.9% to 6.3%. The results showed that the airflow volume peaked in the nasopharynx, oropharynx, epiglottis, and larynx, leading to the airflow separation and formation of circulation that tend to cause dust deposition in these regions. As the dust density and inspiratory airflow volume increased, the deposition fraction of small dust particles (<1μm) in the upper airway slightly changed, and most of them escaped to the lung. For 7.07 μm dust particles, as the dust density increased from 1210 kg/m3 to 2750 kg/m3, the escape rate decreased from 31.43% to 0.48%, and this trend can be seen in the fitting function of escape rate and inspiratory airflow volume Y7.07μm=(80–1.37ν + 0.0064ν2) × 100%. When the dust particle diameter exceeded 20 μm, the impact of dust density was weakened by the large size of the dust, and the escape rate was close to 0% when the inspiratory airflow volume was 50–110 L/min. This study can provide theoretical support for the research and development of respiratory dust sensors and targeted dust prevention technologies.