High-viscosity PETG or PCTG polymerization reactor and method for polymerizing PETG or PCTG

A polymerization reactor for preparing a PETG or PCTG melt, the PETG or PCTG melt having an intrinsic viscosity above 0.770, wherein, the polymerization reactor is a horizontal polymerization reactor, and comprises a main body containing a chamber internally, the main body comprises a low viscosity zone, a med-high viscosity zone and a high viscosity zone arranged in sequence along the axial direction of the polymerization reactor, the viscosity of the PETG or PCTG melt in the low viscosity zone, the med-high viscosity zone and the high viscosity zone increases in sequence;

• the polymerization reactor further comprises two agitating shafts, one agitating shaft is arranged in the low viscosity zone, and the other agitating shaft is arranged in the med-high viscosity zone and the high viscosity zone;
• the two agitating shafts are respectively provided with a plurality of disc reactors, the disc reactors in the low viscosity zone are six˜eight disc combinations, with three˜ten discs in each combination;
• the disc reactors in the med-high viscosity zone are five˜eight disc combinations in form of two-disc or three-disc combination;
• the disc reactors in the high viscosity zone are single discs, and the single discs are arranged in the polymerization reactor in a detachable manner;
• a combination of scrapers is further arranged on a wall of the polymerization reactor between each two adjacent single discs in the high viscosity zone, the combination of scrapers comprises a plurality of scrapers, and the distance between each scraper and adjacent single discs is different;
• the disc reactors in the high viscosity zone comprise circular rings and a plurality of spokes arranged inside the circular rings, the circular rings comprise first portions and second portions, the first portions are fixedly connected to the plurality of spokes, respectively, and the second portions are detachably connected to the first portions;
• and
• the plurality of scrapers is arranged vertically, with the end directions of the scrapers pointing towards the axes of the agitating shafts, and the projections of the plurality of scrapers on the plane where the disc reactors are located are on the same circle.