Microfiltration rotary vacuum filtration

At the end of Section 7.2.1, the process of rotary vacuum filtration is described. Here the membrane containing the particulate cake/deposit (see Figure 6.3.25(a)) is moved perpendicular to the pressure induced crossflow causing filtration through the filter. If we imagine the coordinate system to be fixed to the membrane, then the system configuration is similar to the crossflow microfiltration briefly considered earlier (Figure 6.3.25(b)) where the liquid slurry/suspension moves parallel to the membrane but perpendicular to the direction of the force. 

Consider a typical antibiotic production process, as illustrated in Figure 11.1.1. The antibiotic is present in a fermentation broth as a very dilute solution in the presence of considerable soluble impurities, as well as a significant concentration of whole cells and cellular debris. The particulate materials, such as whole cells, cell debris, etc., are removed first by filtration or centrifugation. The filtration method is described under rotary vacuum filtration (Section 7.2.1.5) or microfiltration (Section 7.2.1.4) of the tangential-flow type (TFF). Centrifugation is illustrated in Sections 7.3.2.1 and 7.S.2.2 via different types of centrifuges. This step has heen characterized as removal of insolubles (Belter et al, 1988) - it is essentially separation of cellular particles from a liquid solution of the product. 

Pharmaceutical Removal of suspended matter is a frequent application for MF. Processes may be either clarification, in which the main product is a clarified liquid, or solids recovery. Separating cells or their fragments from broth is the most common application. Clarification of the broth in preparation for product recovery is the usual objective, but the primary goal may be recovery of cells. Cross-flow microfiltration competes w l with centrifugation, conventional filtration by rotary vacuum filter or filter press and decantation. MF delivers a cleaner permeate, an uncontaminated, concentrated cell product... 

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