Study On Performance Of HEPA ﹠ ULPA Filter Media Based On The MPPS Method

With the development of modern industry, science and technology, people need to research higher efficiency air filter media to meet higher requirement of operation environment, and this causes the development of modern air cleaning technique. Testing filter media is an important step to check the performance of filter media, and testing method develops with the filter market. The method of most penetrating particle size is very popular in Europe currently, and America uses it too. In the near future, it will replace other testing methods in the world.Our national standard has not adapted to the development of filter media market. In order to enforce our competition, we build a testing system according to EN1822, it is based on particle counting methods, by determining the most penetrating particle size and efficiency of filter media, we can classify class of the filter media.We choose fine apparatus to ensure the reliability and stability of testing results. And experimental data show that seven minutes after the aerosol generator turn on, the concentration and the size distribution of the aerosol will remain constant throughout the test; we should choose a suitable dilution ratio because it determines the precise and extent of test; the sampling air flow is not equal to 2.83L/min, and it should be modified on the basis of experiment.Through the analysis of error theories and the data of test, we make the testing system more suitable for application. Experimental data show that when introducing several pieces of the same kind of filter media in test, the efficiency is exponential function of pieces, and the pressure drop is linear function of pieces; efficiency of filter media has something to do with type of filter media, particle size, filter medium face velocity, and so on, the most penetrating particle size of the filter medium will decrease as filter medium face velocity increases, in order to contrast different test methods, we suggest using filter medium face velocity of 5.33cm/s, that is 32L/min in volume flow rate.