Batch-operated large-scale vacuum filters

Batch-Operated, Large scale Vacuum Filters 43 3... 

In other systems, where batch operation is practised, e.g. in large-scale vacuum filters or pressure units, extra time may be allowed, in order to achieve high solute removal Generally, extra wadi time means lower productivity per unit area vdien becomes unduly high, steps... 

Chapter 11 deals with the application of these concq>ts to process calculations in large-scale vacuum and pressure filters used in continuous and batch processes, hi all the examples presented, the importance of the consideration of the fiill filter cycle is stressed. Along with the development of modem fitters capable of operating in thin-cake conditions, units are also included for the dewatering of cakes by gas displacement and squeezing. 

DISCONTINUOUS VACUUM FILTERS. Pressure filters are usually discontinuous vacuum filters are usually continuous. A discontinuous vacuum filter, however, is sometimes a useful tool. A vacuum nutsch is little more than a large Buchner funnel, 1 to 3 m (3 to 10 ft) in diameter and forming a layer of solids 100 to 300 mm (4 to 12 in.) thick. Because of its simplicity, a nutsch can readily be made of corrosion-resistant material and is valuable where experimental batches of a variety of corrosive materials are to be filtered. Nutsches are uncommon in large-scale processes because of the labor involved in digging out the cake they are, however, useful as pressure filters in combination filter-dryers for certain kinds of batch operations. ... 

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