US 2026/0209162 A1 · CONTINUOUS PROCESS FOR CRYSTALLIZING BIS (2-HYDROXYETHYL) TEREPHTHALATE AND CRYSTALLIZER USED THEREIN

Abstract

Crystallization process of BHET in which a BHET solution is introduced into a crystallizer equipped with an impeller positioned in the lower part of the crystallizer and coaxial to a draft tube, which in turn is coaxial to the internal wall of the tank, which defines an interspace within which a plurality of heat exchange plates are placed in which a cooling fluid circulates. Thanks to the thrust of the impeller, the solution flows inside the interspace where the solution is cooled with high efficiency, thanks to the high exchange surface with the heat exchange plates, without generating excessive turbulence of the liquid. A suspension rich in BHET crystals with a low content of fines is therefore formed, which is then discharged from the crystalliser and sent to the subsequent BHET processing steps.

Claims23

Dependent claims

A process for crystallizing bis(2-hydroxyethyl) terephthalate (BHET) in a continuous manner, which comprises:

introducing a BHET solution into a crystallizer which comprises a tank equipped with an impeller positioned in a lower part of the tank and coaxial to a draft tube arranged inside the tank, where the external wall of the draft tube defines, with the internal wall of the tank, an interspace within which a plurality of heat exchange plates are located;
rotating the impeller so as to generate a thrust of the solution from the bottom upwards, along the longitudinal development direction (S) of the draft tube and consequently a flow of the solution from the top downwards inside the interspace, where the solution cools on contact with the plurality of heat exchange plates in which a cooling fluid circulates, at a temperature such as to cause crystallization of the BHET with formation of a BHET crystal suspension;
and
discharging the BHET crystal suspension from the crystallizer.

1 more element

Dependencies are inferred from the claim text.

Continuous process for crystallizing bis (2-hydroxyethyl) terephthalate and crystallizer used therein

Life of this patent

Continuous process for crystallizing bis (2-hydroxyethyl) terephthalate and crystallizer used therein

Life of this patent

Abstract

Claims23