ABSTRACT
Cross-flow filtration can be utilized with micro or ultrafiltration membranes. The fluid sweeps over the membrane layer and therefore keeps it unblocked. Dead-end filtration operates on the principle of passing a fluid feed stream through a filter device by means of a pressure drop, usually applied by either a pump or compressed gas pressure before the filter device. Cross-flow filtration gets its name because the majority of the feed flow travels tangentially across the surface of the filter, rather than into the filter. In the hollow fiber filtration process, no phase change is involved. Consequently, it needs no latent heat. This makes the hollow fiber membrane have the potential to replace some unit operations that consume heat, such as distillation or evaporation columns. When the ultrafiltration media is replaced with a microporous microfiltration membrane, one has the option of performing a wide range of separations involving larger species, while usually operating at much lower pressures.
