| 摘要 |
The invention relates to a method for increasing the molecular weight of a polymer granulate from a polycondenstion system. Said polymer granulate is at least partially crystallised and is brought into direct contact with nitrogen-containing treatment gas which is guided in a circuit in a post condensation stage. The temperature of the polymer granulate in the post condensation stage is increased to between 175-250 DEGREE C with respect to the granulate from the polymer condensation system. A nitrogen rich unburnt gas which is obtained from air by means of physical methods and which has a residual oxygen content of between 0.1 5 vol. % and which also contains hydrocarbons is added to the treatment gas before it is directed via an oxidation stage and subsequently, to the post condensation stage.
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