Apparatus for continuous stirring and process for continuous polycondensation of polymer resin

An apparatus for continuous stirring, which comprises a horizontal elongated cylindrical vessel with an inlet for supplying a liquid feed at one end thereof in the longitudinal direction, an outlet for discharging a stirred and mixed liquid product at the other end thereof and an outlet for volatile matters at the top thereof, and two rotating blade assemblies rotatable in the direction opposite to each other, provided in parallel to each other in the horizontal direction in the vessel, where a liquid feed supplied into the vessel from the inlet is moved from the one end to the other by rotation of the two rotating blade assemblies in the direction opposite to each other, while stirring and mixing the liquid feed, the two rotating blade assemblies each comprising a first rotor shaft supported by a bearing provided at one end of the vessel in a rotatable manner, a second rotor shaft supported by another bearing provided at the other end of the vessel in a rotatable manner, a first support member fixed to the first rotor shaft near the one end of and within the vessel, a second support member fixed to the second rotor shaft near the other end of and within the vessel, a plurality of connecting members spanned between the first support member and the second support member, provided in a predetermined distance from a substantial rotating shaft center in the radial direction, and a plurality of plate-shaped stirring blades provided in parallel to one another in the longitudinal direction of the substantial rotating shaft center and fixed to a plurality of the connecting members, thereby forming a clearance in the region of the substantial rotating shaft center, wherein the plate-shaped stirring blades are pairs of plate-shaped members, each pair being arranged symmetrically about the substantial rotating shaft center.

A process for continuous polycondensation of polymer resin in an apparatus for continuous stirring, which comprises a vessel, and two rotating blade assemblies rotatable in the direction opposite to each other, provided in parallel to each other in the horizontal direction in the vessel, where a liquid feed supplied into the vessel from an inlet is moved from one end to other therethrough by rotation of the two rotating blade assemblies in the direction opposite to each other, while stirring and mixing the liquid feed, the two rotating blade assemblies each comprising a first rotor shaft supported by a bearing provided at one end of the vessel in a rotatable manner, a second rotor shaft supported by another bearing provided at the other end of the vessel in a rotatable manner, a first support member fixed to the first rotor shaft near the one end of and within the vessel, a second support member fixed to the second rotor shaft near the other end of and within the vessel, connecting members spanned between the first support member and the second support member while forming a clearance on the region of a substantial rotating shaft center, and a plurality of plate-shaped stirring blades provided in parallel to each other in the longitudinal direction of the substantial rotating shaft center and fixed to the connecting members, wherein the plate-shaped stirring blades are pairs of plate-shaped members, each pair being arranged symmetrically about the substantial rotating shaft center, characterized by continuously supplying a polymer resin having a low degree of polymerization as the liquid feed into the vessel from the inlet, stirring the liquid feed by rotation of the two rotating blade assemblies in the direction opposite to each other, thereby carrying out good surface renewal and evaporation of volatile matters, and moving the liquid feed towards the outlet, thereby enhancing the degree of polymerization.