Filtration centrifuges pusher

Rapid filtration is accomplished with belts, top-feed drums or pusher-type centrifuges. 

FIGURE 58.20 Pusher centrifuge (1, feed pipe 2, solids collector 3, feed cone 4, slotted screen 5, basket 6, filtrate collector 7, pnsher plate 8, pusher plate 9, basket 10, pusher ring 11, scraper 12, wash pipe 13, basket). (From Mitsubishi Kakoki Kaisha, Ltd., licensed by Kracess Maffei Process Technology AG. With permission.)... 

One of the most commonly used solid-liquid separation methods in crystallization processes is centrifugal filtration, such as continuous pusher and batchwise peeler centrifuges shown schematically in Figure 64.10. A manufacturer of centrifuges used in crystallization processes is KMPT AG [52]. In addition, Nutsche filters, frame pressure filters, and belt filters have also been used. Most of these filters have a possibility of cake washing which is important for the final purity as discussed earlier. 

The salt removed in the solid bowl centrifuges is of less value than that removed in the primary (pusher) centrifuges. It usually is allowed to drop into a tank in which it is redissolved in the cell liquor and then recycled to the evaporators. The solid-bowl centrifugate still contains traces (<0.1%) of very line solid salt. The next step therefore is filtration, described below in Section 9.3.2.6. Some of the salt fixtm the centrifuges may be used in that step. 

Figure 3.36 Pusher centrifuge schematic. A, Slurry B, solids C, filtrate D, wash liquid.

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