Batch-Operated, Large-scale Vacuum Fibers

As discussed in Chapter 9, optimisation of the batch operation of vacuum leaf filters has been discussed in the hterature [Maracek and Novotny, 1980] in hich a mathematical model 

Many suspensions of solids in liquids are difiBcult to separate by gravitational, centrifugal, or vacuum techniques by reason of slow settling characteristics, poor fiherability, high solids content and other fectors. hi this circumstances, iiere large separating areas may prove necessary, the use of pressure filtration equipment is indicated. 

Slow-filtering slurries, containing finely divided solids tend to require the application of elevated pressures, in order to maintain adequate flow. Stringent washing requirements may lead to the consideration of the batch-operated, pressure filters described in this section. 

In the units descnbed below, fluid pressure necessary for filtration is g erated by pim]ping. Pressures are usually below 600 kN/ni but in some machines, hi er values are used, e.g. iq to 140 bar in those madunes fitted with fiicilities for cake squeezing afiier filtration. 

An extremely large variety of presses are available in vbich three groups may be noted  

---