On the residence time in polyester (PET) polymerization reactors
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As I have been conducting research on PET polyester recently, the residence time of the materials in each reactor during the pre-polycondensation and final polymerization stages affects the proper progress of the work. I would appreciate your assistance regarding how to calculate this residence time and what data should be used for that purpose. I hope relevant experts can help and resolve this issue. Thank you all very much.
2# Chen Xuhui, could you be more detailed? I know how to apply what you're saying as well.
Temperature. Liquid level. Pressure. Agitator speed. Catalyst (type, concentration). Esterification degree in the esterification stage. =. =! It depends on the system load... The residence time varies a bit...
1. Simply put, the residence time is capacity/material flow rate. Capacity unit: Kg. The material flow rate is in units of Kg/h. The general material flow rate equals the production volume, and you should know what that production volume is. 2. Capacity calculation = volume * density. A density of 1.35–1.4 is generally sufficient. (The solid density of PET is 1.4; there are no data available for its molten state, so 1.35 should be a reasonable value). 3. The source of the volume data should be the measurement results taken of each reaction vessel before starting up the system. There should be volume data corresponding to different liquid levels. 4. Since the amount of material removed by vacuum during the polymerization stage is small and can be ignored, if an accurate calculation is required, the flow rate of the final condensed material = output * (1+0.2%), and the flow rate of the pre-condensed material = output * (1+2%)