Intelligent control method of PTA particle size in fine terephthalic acid production device

Abstract

An intelligent method for controlling the granularity of PTA particles in refined terephthalic acid (PTA) production includes such steps as selecting the temp and discharge flow of hydrogenating reactor, and the liquid levels and temp of the first and the second crystallizers and using them as the input variables of the soft measuring system of granularity, creating the affection relation of primary operating parameters to PTA granularity, real-time continuous acquisition of procedure data as the soft measured values, determining the difference between settings and measured values, and automatically controlling the liquid levels and temp of the first and the second crystallizers.

Description

1. Technical field [0001] The invention belongs to the field of chemical engineering and automatic control, and relates to an intelligent control method for the particle size of PTA products in the production of purified terephthalic acid (hereinafter referred to as PTA, namely Pure Terephthalic Acid). 2. Background technology [0002] PTA is an important raw material for the production of polyester (PET). Since the production of PET mostly adopts the direct esterification and polycondensation process of PTA, many factors related to the quality of PTA products (such as crystal particle size, impurity content, etc.) The preparation and transportation of PTA slurry have great influence. Secondly, according to the MIRES crystallization theory and the introduction of relevant technical data, one of the particle size indicators of PTA products - the increase of the average particle size is beneficial to the stability and slurryability of PTA slurry. As the use of polyester becom...

AI Technical Summary

Problems solved by technology

[0007] In the PTA production process, as far as the current existing technology is concerned, the particle size cannot be measured online. Usually, the mixed samples collected at multiple points are manually analyzed once a day.

Due to the large analysis lag in manual analysis, when the particle size of PTA changes, it is often impossible to adjust the operating conditions in time, or, due to the existence of many influencing factors, it is impossible to rely on manual operation experience alone. Quantitative adjustment of two operating variables at the same time may cause "overadjustment" or slow adjustment of product particle size, which will directly affect product quality.

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