Patent ID: 6267934
Filing Date: 2001-07-31
Classification: B01D,C01B

Abstract:
An industrial apparatus for the manufacture of persalt in a narrow particle size distribution by crystallization-classification comprising a crystallization vessel of cylindrical shape equipped with a rotary stirrer and with a cooling system, wherein:the vessel contains a perforated grid comprising a perforated plate which extends to the entire cross section of the vessel, separating a lower stirred region and an upper region,wherein the perforated grid is horizontal,the stirred region is identified as a formation and growth region, and is equipped with the stirrer and at its base with systems for admission of the reactants comprising starting materials for the manufacture of the persalt,the upper region, which does not have a stirrer, is intended for clarifying the liquid comprising crystallization mother liquors,the grid restricts stirring to the lower region,a cylinder with a diameter less than that of the vessel is arranged below the vessel,in communication with the vessel,is equipped at its base with a system for injection of a solution arising, via a recirculating pump, from a withdrawal pipe whose source is situated at the upper part of the non-stirred region of the vessel, andcomprises a region for classification by elutriation of the particles originating from the stirred region of the vessel, anda device for drawing off the classified particles is connected to the base of the said cylinder.