Apparatus for thermal treatment of granular polymers comprises hopper whose walls have sieve sections with smooth, structured surface, allowing nitrogen-containing gas to be fed through granules, and smooth sections with structured surface

摘要

Apparatus for thermal treatment or post-treatment of granular polymers, especially polyesters, e.g. polyethylene terephthalate, comprises a vertical hopper (1), through which the granules fall, with a rectangular upper section (4) and tapering lower section (5). The walls have sieve sections with a smooth, structured surface whose structure is at right angles to the direction of flow of the granules and of the same size as them, which extend across their whole width and allow a nitrogen-containing gas to be fed through the granules at right angles to their direction of flow. An independent claim is included for a method for thermal treatment or post-treatment of granular polymers using the apparatus in which air or nitrogen is fed through the granules at 80 -120[deg] C in both the upper and lower sections of the hopper.