Esterification and polymerization double-kettle apparatus

Abstract

The invention relates to an esterification and polymerization double-kettle apparatus. The apparatus comprises an esterification pre-condensation reaction tower and a stirring-free polymerization reactor, wherein a pre-condensation discharging hole of the esterification pre-condensation reaction tower is communicated with a feeding hole of the polymerization reactor through a pre-condensation melt conveying pump; a liquid distribution plate is arranged at the upper part of an inner cavity of the polymerization reactor; a falling-film tube is arranged in the liquid distribution hole; a hot medium heating tube is inserted in an inner cavity of the falling-film tube; the feeding hole of the polymerization reactor and a vacuumizing hole are formed in the outer wall of the upper part of a cylinder body; a discharging spiral and a polymer discharging hole are formed in the bottom of the polymerization reactor; an annular liquid distribution groove is formed in a part, corresponding to the feeding hole of the polymerization reactor, of the inner wall of the cylinder body; a uniform annular gap is reserved in the lower end of the liquid distribution groove; a liquid collection groove is formed in the inner wall of the lower part of the cylinder body; a middle melt outlet communicated with the liquid collection groove is formed in the outer wall of the cylinder body and is communicated with a middle melt inlet through a middle melt conveying pump; the middle melt inlet is formed in the upper part of the liquid distribution plate. The apparatus is compact in structure, small in occupied area and high in production efficiency.

Description

technical field [0001] The invention relates to a two-pot device for esterification polymerization, which belongs to the technical field of polyester production. Background technique [0002] In the prior art, the esterification reaction and polycondensation reaction during polyester production are generally carried out in independent reaction towers or reactors, such as the Chinese invention patent with publication number CN101618304B, which discloses an esterification reactor composed of multiple Each tray is composed of a downcomer and a gas riser. The gas riser is connected to a rotatable gas distributor, and the gas distributor is composed of an induction pipe, a fan and a nozzle. Each tray retains a certain level of liquid with a solid catalyst in the liquid. The liquid phase is the component containing carboxylic acid, which flows down from one esterification tray to the next tray in the reactor, and countercurrently reacts with the rising alcohol vapor. [0003] Th...

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Problems solved by technology

[0006] After the PET melt enters the inner cavity of the polymerization reactor, the heated area is relatively small, and only one polymerization reaction is carried out, the reaction speed is slow, and the production efficiency is low; the small molecules produced by the reaction are easy to carbonize on the wall of the kettle, fall into the material, and produce Black spot material, often need to stop and wash the kettle, the product quality is unstable, and the operation cycle is short

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