Cooling system for polymer processing

A system for the solid phase polymerization of polymers wherein cold amorphous polymer is introduced to one or more crystallizers and heated to crystallize the polymer, the crystallized polymer is discharged to a reactor for polymerization of the polymer, and the hot polymer product of the reactor is discharged to a fluid bed cooler for cooling of the polymerized product, said fluid bed cooler including an inlet for the hot polymer and an inlet for gas used for agitating the fluid bed, and means for discharging the cooled polymer and the off-gas from the cooler after contact of the gas with the polymer, and including at least one spray nozzle located in said cooler at a position adjacent the upper level of the polymer in the cooler, and means for introducing water through said nozzle and into said cooler for contact of the water with the polymer to achieve cooling of the polymer as a result of the vaporization of the water.