Patent ID: 7540884
Filing Date: 2009-06-02
Classification: B01D

Abstract:
1. A process for purifying removal of crystals from their suspension in mother liquor, in which the suspension is fed to a washing column which has a wall which encloses a process chamber, and which wall on its side facing away from the process chamber contacts a first contact area and on its side facing towards the process chamber contacts a second contact area, mother liquor from the suspension fed into the process chamber is passed out of the process chamber while holding back the crystals and forming a crystal bed in the process chamber, the crystal bed is conveyed within the process chamber, at least one force other than gravity acts in the process chamber in the conveying direction of the crystal bed and conveys the crystal bed within the process chamber, pure melt comprising molten crystals which have been purifyingly removed by the process claimed is conducted in the process chamber in countercurrent to the crystal bed in such a manner that a washing front forms in the crystal bed which divides the crystal bed into a mother liquor zone and a pure melt zone,