CROSSFLOW vs. DEADEND

Dead-end FiltrationWhen using a dead-end filtration technique, all the fluid passes through the membrane and all particles larger than the pore sizes of the membrane are stopped at its surface. Particle size prevents contaminants from entering and passing through the membrane. This means that the trapped particles start to build up a "filter cake" on the surface of the membrane which reduces the efficiency of the filtration process until the filter cake is washed away in back flushing.


Cross flow FiltrationIn cross flow filtration, the fluid feed stream runs tangential to the membrane, establishing a pressure differential across the membrane. This causes some of the particles to pass through the membrane. Remaining particles continue to flow across the membrane, "cleaning it". In contrast to the dead-end filtration technique, the use of a tangential flow will prevent thicker particles from building up a "filter cake".