Respiratory dust and dust fall from the mechanized excavation faces of coal mines are crucial issues that require immediate attention. The dust fall technique for two-phase gas–water spraying is effective in solving these issues. We designed a spray dust fall simulated experimental system to test the dust fall efficiency for six grain sizes of water mist: D50 = 9.00 μm, 18.75 μm, 29.87 μm, 49.85 μm, 75.85 μm, and 116.47 μm, respectively. The results demonstrate that the smaller the D50 of the water mist particles, the better is the trapping effect of the respiratory dust. The main dust catching stage of water mist of different particle sizes is different. The main dust catching stage of water mist of small particle size is the initial contact stage of mist particles and respirable dust, while the main dust catching stage of water mist of large particle size appears later. The research findings will lay a theoretical groundwork for the application of new-type nozzle in the coal mines and provide technical support to the clean production of the coal mines.

煤矿机械化工作面产生的呼吸性粉尘和灰尘是至关重要的问题，需要立即引起注意。两相气-水喷雾降尘技术有效地解决了这些问题。我们设计了一种喷雾降尘模拟实验系统，以测试六种粒径的水雾的降尘效率：D50分别为9.00μm，18.75μm，29.87μm，49.85μm，75.85μm和116.47μm。结果表明，水雾颗粒的D50越小，呼吸粉尘的捕集效果越好。不同粒径的水雾的主要捕尘阶段不同。小粒径水雾的主要捕尘阶段是雾粒与可吸入粉尘的初始接触阶段，而大粒径水雾的主要捕尘阶段出现较晚。研究成果将为新型喷嘴在煤矿中的应用奠定理论基础，并为煤矿的清洁生产提供技术支持。