ABSTRACT
Many of the difficulties associated with conventional filtration can be eliminated if the slurry flow is tangential to rather than directly into the filtration media. Cross flow filtration (CFF) utilizes a high fluid circulation rate tangential to the filtration barrier to minimize the accumulation of particles at the filter surface. The filtration rate increases that are obtained with CFF compared to conventional filtration permit the use of commercially available microporous or ultrafiltration membranes for retaining colloidal and/or micron-sized particles. Increases of two orders of magnitude have been observed with microporous membranes. The polarization of the filter occurs because particles are transported to the surface by the solvent and are retained while the solvent passes through. Blatt et al. have proposed that the major difference between the effect of macrosolute and particulate polarization results from the differences in particle size of the particles that constitute the polarized layer in the two cases.
