Influence of ventilation arrangements on particle removal in industrial cleanrooms with various tool coverage

This paper aims to investigate the influence of comparative ventilation arrangements (wall-return, locally balanced ceiling-return, and four-way ceiling-return) on the airflow distribution and particle fates within cleanrooms of ISO cleanliness class 7 with various tool coverage ratios (0%, 38%, and 60%). Computational fluid dynamics (CFD) was employed to analyze and compare the influence of the three ventilation arrangements on concentrations for particles of various sizes (diameters ranging from 0.01 to 100 mu m) in the cleanrooms. The techniques of Eulerian and Lagrangian in CFD were employed for solving the continuous fluid and tracking the particle trajectory, respectively. The outcomes from this study suggested that particle removal rates for the given cleanrooms were significantly affected by the tool coverage ratios, the design of ventilation, and the particle sizes of concerns. In the cases of heavy tool coverage, the locally balanced ceiling-return ventilation arrangements can minimize the need for the relocation of the production lines and layouts of the production tools in cleanrooms, and may provide viable solutions to effective contamination without compromising contamination effectiveness or efficiency.