Improving Vertical Airflow Uniformity Considering the Structures of the Lower Plenum in a Cleanroom

하부 플레넘 구조물 조건을 고려한 클린룸의 편류 개선 방법

  • Published : 2008.01.10

Abstract

To achieve the unidirectional airflow in a cleanroom, we need to predict accurately the static pressure losses at the lower plenum and to control properly the opening pressure ratio of access floor panels based on these pressure losses. At first, the present study proposed a correlation to predict the velocity distribution at the lower plenum, because the accuracy to predict pressure losses at the lower plenum depends on how to calculate the velocity correctly against the inner structures at the lower plenum. In the second place, this study proposed correlations which considered the effect of inner structures such as columns, ducts and equipments at the lower plenum on pressure losses. In order to test the accuracy of these correlations, we compared air flow patterns before regulating the opening ratio of access floor with those after regulating. Results after regulating the opening ratio of access floor show good unidirectional uniform airflow pattern. So the present method can be used as an important tool to control the air flow in a cleanroom.

Keywords

References

  1. SPS-KACA003-133, Test methods for performance evaluation of cleanrooms and associated controlled environments, Korea Air Cleaning Research Association, 2000
  2. Kang, S. H., Jeon, W. P. and Oh, M. D., 1990, Effect of the floor pannel of flows in a vertical laminar flow type clean room, Korean Journal of Air-conditioning and Refrigeration, Vol. 2, No. 4, pp. 303-315
  3. Park, M. S., Lee, J. H., Ahn, K. H. and Kim, J. H., 1993, On the characteristics of the flow with opening and shutting of access panels in a clean room, Korean Journal of Air-conditioning and Refrigeration, Vol. 5, No. 1, pp. 55-64
  4. Cheng, M., Liu, G. R., Lam, K. Y., Cai, W. J. and Lee, E. L., 1999, Approaches for improving airflow uniformity in unidirectional flow cleanrooms, Building and Environment, Vol. 34, pp. 275-284 https://doi.org/10.1016/S0360-1323(98)00028-6
  5. Noh, K. C, Oh, M. D. and Lee, S. C., 2005, A numerical study on airflow and dynamic cross-contamination in the super cleanroom for photolithography process, Building and Environment, Vol. 40, pp. 1431-1440 https://doi.org/10.1016/j.buildenv.2004.11.016
  6. Launder, B. E. and Spalding, D. B., 1972, Lectures in mathematical models of turbulance, Academic Press, England
  7. Fluent Inc., Fluent V6.3 User Guide, Fluent Inc., 2006
  8. Kim, D. K., Cho, S. J., Moon, I. H. and Kim, J. J., 2003, A study for improving airflow uniformity in vertical unidirectional flow cleanroom with FFUs, Proceedings of the SAREK Summer Annual Conference, pp. 1-7