Periodic backflushing

Fouling problems have been solved by a periodic backflush-ing of the membrane. 

Park, B. G., Lee, W. G., Chang, Y. K., Chang, H. N. (1997). Effects of periodic backflushing with filtrate on filtration performance in an internal-filtration bioreactor. Bioprocess Engineering, 16, 253—256. 

Particulate deposition, fouling and adsorption of molecular species at the membrane surfaces often lead to lower than expected permeate fluxes. While chemical cleaning and periodic backflushing/backpulsing with permeate or compressed gas can temporarily increase fluxes, large installed membrane areas may be required to achieve the desired separation rates. This, in conjunction with relatively high pumping duties, means that both capital and... 

Figure 2.22 Scanning electron micrographs of CA membranes after 2 h of filtration of 0.1 g L yeast suspension with periodic backflushing using APj = APj, = 3 psi, tf = 60s, tj, = 10s and wall shear rate y = 640s both with (left) and without (right) recycle of the retentate to the feed reservoir.

Periodic backflushing of the membrane using the permeate (Rodgers and Spark, 1992)... 

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