Abstract: Objective To study the dust diffusion law of copper alloy workpiece polishing operation in a mechanical manufacturing enterprise in Beijing,analyze the effectiveness of existing ventilation facilities,and to provide theoretical support for occupational health engineering governance. Methods In February 2024,based on the bi-directional coupling discrete phase model,the diffusion characteristics of copper alloy dust in the polishing workshop of a machinery manufacturing enterprise were simulated by numerical simulation software,and the differences between the measured values and the simulated values were analyzed and compared. Results The total number of mesh in the 3D model was 1.136×10⁶ million,and the average mesh quality was 0.84. The air flow effect was affected by the air flow generated by dust diffusion,doors and windows,and the equipment layout in the workshop,and the wind speed at the personnel operating position was about 0.04-0.06 m/s. The maximum concentration of dust on the working surface of the polishing table was 50 mg/m³,and the dust concentration decreased with the increase of the distance from the polishing table. The variation trend of the measured values was basically consistent with that of the simulated values,and the deviation range was -5.64%-10.63%. Conclusion The dust in the polishing workshop mainly accumulates around the polishing table and in the corner eddy current area,among which the dust on the north side of the polishing table overlaps with the breathing belt of the operator. It is difficult to control dust effectively under the existing ventilation conditions,and priority should be given to the mobile local exhaust system. If a fixed local exhaust system is set up,the influence of eddy current and countercurrent area should be considered.

Key words: Copper dust, Numerical simulation, Dust diffusion, Ventilation dust removal