CN111804255A - Method for enhancing stirring effect of esterification reaction kettle - Google Patents

Abstract

The invention discloses a method for enhancing the stirring effect of an esterification reaction kettle, which comprises the following steps of firstly, carrying out a plurality of times of increasing speed increasing during stirring of a stirrer of the esterification reaction kettle, and maintaining for 5-15min after each time of increasing speed; and step two, performing descending deceleration for a plurality of times, and maintaining for 5-15min after each deceleration. The method for enhancing the stirring effect of the esterification reaction kettle is beneficial to the product quality and stable production.

Description

Method for enhancing stirring effect of esterification reaction kettle

The technical field is as follows:

the invention relates to the field of polyester production, in particular to a method for enhancing the stirring effect of an esterification reaction kettle.

Background art:

the polyester production is a production process of esterification reaction and polycondensation reaction of Purified Terephthalic Acid (PTA) and Ethylene Glycol (EG). Whether the esterification reaction is sufficient in the polyester production process determines the stability and the product quality of subsequent production. In addition to mainly controlling technological parameters such as temperature, pressure and the like in the esterification reaction kettle in the esterification reaction process, the speed of a stirrer of the esterification reaction kettle is also a very important parameter. The stirrer plays the roles of uniformly mixing materials, strengthening heat and mass transfer and fully contacting the materials to generate chemical reaction in the esterification reaction. If the stirrer rotates at a fixed speed and the material in the reaction kettle flows in a fixed direction, the flow speed is constant. In this case, slow-flowing zones or dead-flowing zones are formed in the kettle, and the materials in these zones are not reacted sufficiently, which in turn affects the overall product quality and production stability.

The invention content is as follows:

the invention aims to solve the technical problem of providing a method for enhancing the stirring effect of an esterification reaction kettle, which is beneficial to product quality and stable production.

The technical proposal of the invention is to provide a method for enhancing the stirring effect of an esterification reaction kettle, which comprises the following steps,

step one, gradually increasing and increasing speed for a plurality of times when a stirrer of an esterification reaction kettle is used for stirring, and maintaining for 5-15min after each speed increase;

secondly, performing descending deceleration for a plurality of times, and maintaining for 5-15min after each deceleration;

and step three, recovering the speed before speed increasing after speed reducing, and performing the operations of the step one and the step two after the operation is performed for 5-15min at intervals, so as to circulate.

Preferably, the method comprises the following steps,

firstly, accelerating for two times when a stirrer of an esterification reaction kettle is used for stirring, wherein the first acceleration is 5%, and the operation is carried out for 10 min; after the first acceleration is finished, the speed is increased by 5% again on the basis of the first acceleration for the second time, and the operation is carried out for 10 min;

step two, after the two times of speed-up operation are finished, the speed reduction is started, the speed reduction is performed for 5% for the first time, and the operation is performed for 10 min; after the first deceleration is finished, the speed is reduced by 5% again on the basis of the first deceleration for the second time, and the operation is carried out for 10 min;

and step three, recovering the speed before increasing, and operating for 10min at intervals, and then performing the operation of the step one and the step two to circulate.

Compared with the prior art, the invention has the following advantages after adopting the scheme: through changing esterification reaction cauldron agitator speed, the flow direction, the flow velocity of messenger's material in esterification reaction cauldron have also changed, let material mixing homogeneity become good, fully obtain the contact between the material, esterification reaction is more abundant, finally makes polyester production stability reinforcing, and product quality obtains guaranteeing and promotion.

The specific implementation mode is as follows:

the invention is further illustrated with respect to specific embodiments below:

example 1

A method for enhancing the stirring effect of an esterification reaction kettle comprises the steps of firstly setting the required rotating speed for stirring the esterification reaction kettle according to the requirements of the polyester production process, and then automatically controlling the speed increase and the speed reduction by utilizing the multi-step control function of a frequency converter,

firstly, accelerating for two times when a stirrer of an esterification reaction kettle is used for stirring, wherein the first acceleration is 5%, and the operation is carried out for 10 min; after the first acceleration is finished, the speed is increased by 5% again on the basis of the first acceleration for the second time, and the operation is carried out for 10 min;

step two, after the two times of speed-up operation are finished, the speed reduction is started, the speed reduction is performed for 5% for the first time, and the operation is performed for 10 min; after the first deceleration is finished, the speed is reduced by 5% again on the basis of the first deceleration for the second time, and the operation is carried out for 10 min;

and step three, recovering the speed before increasing, and operating for 10min at intervals, and then performing the operation of the step one and the step two to circulate.

According to the invention, the flow direction and the flow speed of the materials in the esterification reaction kettle are changed by changing the speed of the stirrer of the esterification reaction kettle, so that the mixing uniformity of the materials is improved, the materials are fully contacted, the esterification reaction is more full, the production stability of the polyester is enhanced, and the product quality is ensured and improved. The method has the specific advantages that 1, the control method has clear thought and is relatively easy to realize. The esterification reaction is more sufficient through the speed increasing and decreasing action of the stirrer, and the production stability is improved; 2. the first esterified ester is tested, and after the method is adopted, the acid value is reduced to 60-62 mgKOH/g from the original range of 58-64 mgKOH/g, the fluctuation range is reduced, the acid value control is more accurate, the stability is better, and the esterification rate is improved to a certain extent; 3. after the method for enhancing the stirring effect of the esterification reaction kettle is applied, the acid value is more stable than before, the esterification rate is improved, the breakage rate of filament production is greatly reduced, the breakage rate of the filament of one production line is reduced from 90 times of breakage every 24 hours before to 60 times at present, 50 kilograms of waste filament are generated according to breakage every time, 1500 kilograms of waste filament and 1500 yuan/ton of difference between the waste filament and finished filament can be reduced every 24 hours, the benefit 2250 yuan can be generated every day, and the efficiency of one production line can be increased by 81 ten thousand yuan according to 360 days.

The foregoing is illustrative of the preferred embodiments of the present invention only and is not to be construed as limiting the claims. All the equivalent structures or equivalent process changes made by the description of the invention are included in the scope of the patent protection of the invention.

Claims (2)

1. A method for enhancing the stirring effect of an esterification reaction kettle is characterized by comprising the following steps: comprises the following steps of (a) carrying out,

step one, gradually increasing and increasing speed for a plurality of times when a stirrer of an esterification reaction kettle is used for stirring, and maintaining for 5-15min after each speed increase;

secondly, performing descending deceleration for a plurality of times, and maintaining for 5-15min after each deceleration;

and step three, recovering the speed before speed increasing after speed reducing, and performing the operations of the step one and the step two after the operation is performed for 5-15min at intervals, so as to circulate.

2. The method for enhancing stirring effect of esterification reaction kettle according to claim 1, characterized in that: comprises the following steps of (a) carrying out,

firstly, accelerating for two times when a stirrer of an esterification reaction kettle is used for stirring, wherein the first acceleration is 5%, and the operation is carried out for 10 min; after the first acceleration is finished, the speed is increased by 5% again on the basis of the first acceleration for the second time, and the operation is carried out for 10 min;

step two, after the two times of speed-up operation are finished, the speed reduction is started, the speed reduction is performed for 5% for the first time, and the operation is performed for 10 min; after the first deceleration is finished, the speed is reduced by 5% again on the basis of the first deceleration for the second time, and the operation is carried out for 10 min;

and step three, recovering the speed before increasing, and operating for 10min at intervals, and then performing the operation of the step one and the step two to circulate.