Mathematical model of highly efficient air filtration process for nonwoven fabrics manufactured by paper-making method.

The necessity to provide and maintain high cleanness of air in the rooms of the highestcleanliness classes requires a proper adaptation of selection and designing methods for airfilters. The level of air cleanliness for such rooms is defined numerically by the determinationof the permissible number of dust particles whose diameters are equal or higher than the givenlimit values. Thus, in order to determine in reliable way the level of pollution in the airprepared and supplied to the cleanrooms it is essential to be able to predict the numericalfractional filtration efficiency for every stage of filtration. Such an analytical method for thedetermination of the filtration efficiency carried out at the stage of designing of an aircleaning system and leading to the quantitative assessment of dust concentration in the airbehind the successive falters, will permit a reliable analysis of the possibility of application ofthe specific filtration materials. For this purpose previously developed mathematical modelsfor the process of air filtration should be applied.This article presents a probabilistic model of air filtration process elaborated for filter papersmade of glass fibre. The applied method of modelling allowed to select the most importantparameters of fibres and nonwoven fabrics that (apart from the sizes of dust particles), havean essential influence on the variability of the numerical filtration efficiency. The article alsofocuses on the area of application of the proposed model and the reliability of quantitativeassessment of numerical concentration of dust behind the air filter.