ABSTRACT
The protection of critical components from contamination by particles is the core of clean high-technology manufacturing. Filters are used to purify the air in clean rooms and in process liquids and gases. This chapter presents an overview of filtration technology, and discusses the general performance of filter. The types of particulate filters developed over the years include: fibrous; membrane; fabric; granular bed; and electrostatic– active: applied fields and corona discharge– passive: Rosin-wool, electrets. Interception is simply the collection of a particle contacting a fiber when following a flow streamline. Diffusional particle collection is significant only for submicrometer particles with large diffusion coefficients. The filtration of particles from liquids is much more complex than filtration of particles from gases. Additional forces come into play, such as charge effects, adhesion, absorption, and the hydrophobic or hydrophilic properties of the filter.
