Centrifugal filtration maintenance

Regardless of the machine device, centrifuges are typically maintenance-intensive. Filters can be cheaper in terms of capital and maintenance and should be considered first unless centrifugal equipment already exists. Small facilities (<1000 liters) use filtration, since centrifugation scale-down is constrained by equipment availability. Comparative economics of the two classes of operations are discussed by Datar and Rosen (loc. cit.). 

The disadvantages associated with centrifugation are (I) without the use of chemicals the solids capture is often very poor, and chemical costs can be substantial (2) trash must often be removed from the centrifuge feed by screening (3) cake solids are often lower than those resulting from vacuum filtration and (4) maintenance costs are high. 

The reduction of downtime of the instrument (i.e., operations of pump components, injectors, and detectors) can be controlled to some degree if sample solutions are filtered and/or centrifuged the use of a 0.2- or 0.45-pm-pore-size filter is generally recommend for removal of particulates [15]. Filtration as a preventive maintenance tool for FfPLC analyses is well-documented in the ht-erature [16-18]. 

A throttle valve is sometimes needed with a centrifngal pnmp or filtration is started at a pressnre considerably above that at point B. The curve AB generally is essentially a parabola. The pressnre drop across the cake is essentially the vertical difference between enrves CB and AB. If the centrifugal pump is too large, overheating, particle breakup, and considerable maintenance problems are possible at startup. 

---