Modelling of industrial HEPA filters clogging by solid particles
L. Bouilloux*, S. Artous, J-C. Laborde, O. Norvez, CFA 2003 - 19th Congrès Français sur les Aérosols, 10-11 décember 2003, Paris.
The communication presents some experimental and numerical results related to the clogging, by solid particles, of industrial pleated filters, especially High Efficiency Particulate Air (HEPA) filters used in French nuclear facilities. We propose to describe the clogging of pleated filters in three phases: first an in-depth filtration, as for flat filtering medium, which modifies slightly the filter pressure drop; the second phase corresponds to a filtration on the surface of the filtering medium, along the pleats, and the last phase to a reduction of the filtering area which generates a significant increase in the pressure drop. In a first part of the paper, are summarized some significant results of experiments in order to study the influence of filtration velocity and of particles diameter. The second part concerns different contributions to the modelling of clogging. One results from a dimensionless approach and the other derives from the Novick model in which a term of filtration area reduction is introduced.