Experimental investigation of particle dispersion in cleanrooms of electronic industry under different area ratios and speeds of fan filter units

Surface Cleanliness Maintenance with Laminar Flow Based on the Characteristics of Laser-Induced Sputtering Particles in High-Power Laser Systems

“…Since the Re > 1 regime accounts for the majority of the increase in the distance during particle deceleration and the trend in the Re < 1 regime is similar to that in the Stokes regime (i.e., there is no substantial decline in velocity or increase in distance, as seen in Figure 5 b,c with a particle diameter of 75 μm as an example), the Allen regime is a suitable choice for predicting the maximum attenuation distance throughout the entire timeline. This valuable discovery allows us to quickly pre-calculate the safety distance (beyond which any optical component downstream remains self-cleaning without the use of laminar flows) without the need for precise modeling (e.g., a CFD-DEM coupling method based on the variation of drag and lift coefficients [ 47 ]) or experimentation (e.g., using a particle counter [ 42 ]), once we have obtained V 0 . It was also found that the predicted maximum attenuation distance will increase further by substituting C D in the Stokes regime, and the increase is greater for larger particles (as shown in Figure 5 c).…”

“…Thongsri et al [ 41 ] observed that while particle removal efficiency improves gradually with increasing laminar airflow velocity between 0.25 m/s and 0.65 m/s within the protected area, it also leads to increased pollution of the surrounding area. The removal efficiency of particles larger than 0.5 μm (concentration limit: >2,000,000 particles/ft 3 at 5% coincidence loss) was investigated using laminar flow in a vertical-convection clean room [ 42 ]. The results showed that as the input velocity of the laminar flow decreased from 0.25 m/s to 0.19 m/s, the protection capability within sub-zones remained strong.…”

Ventilation strategies and design impacts on indoor airborne transmission: A review

“…The outcomes showed increasing the ventilation rate reduced the concentration of small particles; however, this escalation of the ventilation rate did not decrease the concentration of larger particles. Shao et al [ 112 ] experimentally investigated particle dispersion through different ventilation rates and Fan Filter Units (FFU) in a test chamber representing a cleanroom. Although more clean air reduces Volatile Organic Compounds (VOCs) and CO 2 , the aerosols and O 3 levels increased in the indoor space.…”

Numerical Investigation of using FDCU on Temperature Distribution in Non-Unidirectional Cleanrooms

“…Moreover, fixed placements of the wall-return air grilles openings add to the uneven temperature distribution due to the interaction between the hot air current from tools and the cold air current from the ceilings [7]. With the increasing application of fan filter units (FFUs) in semiconductor manufacturing a lot of research has focused on improving the performance of FFUs because of their flexible installation [8][9][10]. Zhao et al, [11] proposed a new control strategy of fan filter units (FFUs) based on personnel location within the cleanroom to reduce the operating air volume.…”