APPARATUS FOR HEAT TREATMENT OF POLYESTER PARTICLE AND METHOD OF MULTISTAGE SOLID-PHASE POLYCONDENSATION OF POLYESTER PARTICLE
A multistage method for solid-phase polycondensation of polyester particles, comprising continuous polycondensation in: (1) a first fluidized bed; (2) a first moving bed; (3) a second fluidized bed; and (4) a second moving bed in the stated order along a flow of the particles, wherein the second moving bed has a capacity twice or more as large as a capacity of the first moving bed, is provided.
1 - 47 . (canceled)
48 . A multistage solid-phase polycondensation method for polyester particles, comprising:
using an apparatus for a heat treatment of polyester particles for performing continuous solid-phase polycondensation of the polyester particles, comprising, in the stated order along a flow of the particles:
(1) a first fluidized bed having a temperature of from 100 to 200° C., comprising:
a porous plate, having an inclined part;
an inert gas inlet;
a continuous discharge in a constant amount; and
optionally, a stirring mechanism;
(2) a first moving bed having a temperature of from 190 to 230° C., comprising:
an inert gas inlet; and
a continuous discharge in a constant amount;
(3) a second fluidized bed having a temperature of from 230 to 245° C., comprising:
a porous plate;
an inert gas inlet;
a continuous discharge in a constant amount; and
optionally, a stirring mechanism; and
(4) a second moving bed having a temperature equal to or less than 250° C. and at least 15° C. higher than the temperature of the first moving bed, having an inert gas inlet and a gas exhaust outlet;
wherein the second moving bed has a capacity twice or more as large as a capacity of the first moving bed; and
performing solid-phase polycondensation of polyester particles having an intrinsic viscosity of 0.18 to 0.40 dL/g in the first moving bed of the apparatus for a heat treatment until the intrinsic viscosity increases by 0.03 to 0.10 dL/g; and
performing additional solid-phase polycondensation of the polyester particles in the second moving bed of the apparatus until the intrinsic viscosity becomes equal to or larger than 0.70 dL/g.
49 . The multistage solid-phase polycondensation method for polyester particles according to claim 48 , further comprising:
condensing and recovering part or entirety of organic matter as the by-product of the solid-phase polycondensation; and
using the recovered organic matter as part of raw materials for producing the polyester particles.
50 . The multistage solid-phase polycondensation method for polyester particles according to claim 48 , wherein in an upstream region of the first fluidized bed of the apparatus the polyester particles are uniformly dispersed in the entirety of the region and flow to a downstream region where the particles flow with plug flow property.
51 . The multistage solid-phase polycondensation method for polyester particles according to claim 48 , wherein the second fluidized bed comprises a fluidized bed having plug flow property.
52 . The multistage solid-phase polycondensation method for polyester particles according to claim 48 , wherein in the first moving bed the inert gas inlet is in a lower portion and an exhaust gas outlet is in an upper portion of the moving bed.
53 . The multistage solid-phase polycondensation method for polyester particles according to claim 48 , wherein the first moving bed and/or the second moving bed comprises multiple regions partitioned in upward and downward directions, and a lower portion and an upper portion of each region have a gas inlet and a gas outlet, respectively.
54 . The multistage solid-phase polycondensation method for polyester particles according to claim 48 , wherein the first moving bed and/or the second moving bed comprises multiple regions partitioned in upward and downward directions, and each region has a gas inlet and a gas outlet in a direction transverse to the direction of particle flow.
55 . The multistage solid-phase polycondensation method for polyester particles according to claim 48 , wherein an exhaust inert gas is recycled and a circulation path of the exhaust inert gas comprises removal of organic matter and/or water.
56 . The multistage solid-phase polycondensation method for polyester particles according to claim 55 , wherein the removed organic matter and/or water is recovered by being condensed.
57 . The multistage solid-phase polycondensation method for polyester particles according to claim 55 , wherein the organic matter in the exhaust gas is burnt and the water in the gas is absorbed in the stated order.
58 . The multistage solid-phase polycondensation method for polyester particles according to claim 56 , wherein the condensed organic matter is burnt, and the condensed water is absorbed in the stated order.
59 . The multistage solid-phase polycondensation method for polyester particles according to claim 53 , wherein in an uppermost region of the moving beds organic matter and/or water in the exhaust gas is recovered by being condensed, and in a lowermost region of the moving beds organic matter in the exhaust gas is burnt and water in the exhaust gas is absorbed in the stated order.
60 . The multistage solid-phase polycondensation method for polyester particles according to claim 56 , wherein the removed organic matter is added to raw materials for producing the polyester particles.
61 . The multistage solid-phase polycondensation method for polyester particles according to claim 48 , wherein the first fluidized bed comprises crystallization of the polyester particles, the first and second moving beds comprise a solid-phase polycondensation of the polyester particles, and the second fluidized bed comprises a rapid heating of the polyester particles.