Crystallizer and method for producing phenol-bpa adduct crystals

摘要

Both a crystallizer and method for the evaporative production of phenol-BPA adduct crystals are provided that achieve more uniform crystal growth while suppressing undesired crystal nucleation. The crystallizer includes a cylindrical vessel; a draft tube concentrically disposed within the cylindrical vessel such that an annular space is defined between the vessel and tube; an impeller that circulates liquid in the vessel through the draft tube and the annular space, and a plurality of nozzles mounted around an inner wall of said cylindrical vessel that introduce an evaporative coolant into the vessel. Each of the nozzles includes a discharge end disposed between about 30% and 60% of a radial extent of the annular space, and is located below an upper end of the draft tube a distance of between about 50% to 150% of the diameter of the vessel. Such a nozzle arrangement provides a consistent and uniform concentration of coolant across the surface of the boiling zone that prevents or at least reduces unwanted crystal nucleation on the inner surfaces of the vessel and promotes uniform crystal growth by providing a consistent and uniform degree of supersaturation across the annular space within the boiling zone.