Patent EP-2712881-A1 (EP)
Inventor: CHRISTEL ANDREAS
IPC: B01J3/00
Filed: 2012-09-26
Abstract: Apparatus for continuous pelletization and crystallization of polymer, comprises: unit for forming polymer pellet material and cooling pellet material in a liquid cooling medium; an after-connected unit for drying pellet material; and crystallizer (6) for crystallizing pellet material. The crystallizer: communicates directly via connection line (3) with pre-connected unit for separating liquid cooling medium from pellet material and drying pellet material, so that material to be treated can pass unimpeded from pre-connected unit to downstream unit; and comprises inlet for importing inert gas. Apparatus for continuous pelletization and crystallization of a polymer, comprises: a unit for forming a polymer pellet material and cooling the pellet material in a liquid cooling medium; an after-connected unit for drying the pellet material, where the after-connected unit comprises an exit opening for exporting gas; and a crystallizer (6) for crystallizing the pellet material. The crystallizer: communicates directly via a connection line (3) with the pre-connected unit for separating the liquid cooling medium from the pellet material and drying the pellet material, so that the material to be treated can pass unimpeded from the pre-connected unit to the downstream unit; and comprises an inlet for importing inert gas, where the crystallizer communicates via the inlet with an inert gas tank, so that the pressure in the crystallizer can be increased relative to a pressure in the unit for drying the pellet material. Independent claims are also included for: (1) continuous production of partly crystalline polymer pellet material, comprising: (a) forming the polymer melt into pellet material by adding a liquid cooling medium, and cooling to a temperature above the glass transition temperature of the polymer before or during or after forming the polymer melt; (b) separating the liquid cooling medium from the pellet material in a first treatment space at a temperature above the glass transition temperature of the polymer in a gas phase, where cooling medium separates off transitions into the gas phase; and (c) crystallizing the pellet material in an after-connected second treatment space under an inert gas, where the pellets are directly transferred from the first treatment space into the second treatment space via a connection line, so that the material to be treated can pass unimpeded from the pre-connected unit to the downstream unit, and a pressure (p2) in the second treatment space is set to be above a pressure (p1) in the first treatment space; and (2) retrofitting a plant for pelletization and crystallization of a polymer with the unit for drying the pellet material and the crystallizer, where the crystallization of the polymer in the plant takes place under air, comprising: modifying the existing crystallizer in the plant for operation with an inert gas or alternatively providing an additional crystallizer, which is equipped for operation with an inert gas; and additionally endowing the plant with a control unit (12a) for setting a pressure in the crystallizer, where the control unit can be used to increase the pressure in the crystallizer relative to an ascertained pressure in the unit for drying the pellet material.