Hoechst Aktiengesellschaft

Siegfried Breitschaft

Rolf Holtermann

Polyester granules are crystallized and dried by passing hot gases of 120.degree. to 190.degree. C. in upward direction through the stationary layer of loose polyester granules resting in a cylindrical container on a plane or conical perforated tray slowly rotating about its vertical axis. The hot gas is passed through the material in an amount such that no fluidization is brought about. Under the action of the hot gas the granules agglomerate and the agglomerate is alternately slightly lifted and lowered again by stripping edges on the perforated tray whereby the agglomerate portion resting on the tray is disintegrated and the crystallized granules are discharged through slots behind the stripping edges in the tray.

Process for crystallizing and drying polyethylene terephthalate and

Polyester granules are crystallized and dried by passing hot gasses of 120.degree. to 190.degree. C in upward direction through the stationary layer of loose polyester granules resting in a cylindrical container on a plane or conical perforated tray slowly rotating about its vertical axis. The hot gas is passed through the material in an amount such that no fluidization is brought about. Under the action of the hot gas the granules agglomerate and the agglomerate is alternately slightly lifted and lowered again by stripping edges on the perforated tray whereby the agglomerate portion resting on the tray is disintegrated and the crystallized granules are discharged through slots behind the stripping edges in the tray.

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Augsburg, Germany

Siegfried Breitschaft