高效过滤器现场大气尘检漏方法的理论探讨——国标《洁净室施工及验收规范》编制组系列探讨问题之九

A Theoretical Analysis of Atmospheric Dust Aerosol Method for Leak Testing HEPA/ULPA Filters Installed in Cleanroooms——Part 9 of the Series of Research Practice of the National Standard Task Group for the Code for Cleanroom Construction and Acceptance Te

用射流理论具体论证了大气尘粒子计数器检漏方法(简称漏孔法),普通高效过滤器需要不低于2200粒/L(2.83L/min采样)的上游大气尘浓度,超高效过滤器需要不低于5800粒/L(28.3L/min采样)的上游大气尘浓度。只要扫描特征读数≥1,即可作静止检漏,若再≥3,即可判断为漏。漏孔法比ISO透过率法适用漏孔更小。

With regard to the method for leak testing high efficiency particulate air filters or ultra low penetration air filters installed in clean rooms, a certain discrete-particle counter method, which adopts atmospheric dust aerosols as the aerosol challenge up- stream, is described on the basis of jet theory. This leakage method is a qualitative analysis method. With a theoretical analysis, it is observed that the minimum aerosol concentration for identifying limit leakages of high efficiency particulate air filters and ultra low penetration air filters shall be not less than 2200 （drawing air at a flow rate of 2.83 L/rain） and 5800 （drawing air at a flow rate of 28.3 L/ min） particles per liter, respectively. Stationary leak test should be performed as long as the actual number of particle counts that characterize a designated leak is not less than 1. When stationary leak test is conducted, designated leaks will he defined if particle counts are equal to or greater than 3. This qualitative analysis method may detect smaller leakages than MPPS penetration method introduced by ISO 14644.