Dynamic Crossflow Filter
Crossflow filters are state-of-the-art for substances with poor filtration characteristics. The use of ceramic filter membranes is gaining popularity in successful implementation when other separation processes, besides cake-forming filtration, do not achieve the desired results.
With the Krauss-Maffei dynamic crossflow filter DCF, ANDRITZ was able to successfully enhance dynamic crossflow filtration using two shafts. The improved process is especially suited for processing sensitive or viscous products. The DCF is able to concentrate the retentate to achieve a pasty or sludge consistency. As a result, it is more efficient in recovering valuable elements than any other crossflow filtration technology. Conventional, circulating crossflow filtration minimizes the formation of a clogging layer on the filter’s surface by passing a process medium over the membrane. However, this procedure is inefficient when processing sensitive or viscous products and is generally not advisable. Under these conditions, the feed cannot be concentrated into a high-viscosity retentate.
The technology of the Krauss-Maffei dynamic crossflow filter DCF generates a differential speed in the opposite direction between overlapping membrane discs rotating in the same direction.
This design generates a turbulent crossflow without using a pump to circulate the retentate. The wall shear stress generated is 50% higher than found in conventional crossflow filters. This greatly reduces formation of a clogging layer, while substantially improving the filtration rate at the same time. This advantage is most evident when dealing with high-viscosity retentates.
DCF, Andritz separation