Automatic vacuumizing polyester reactor for chemical industry

Abstract

The utility model discloses an automatic vacuumizing polyester reactor for chemical industry, which comprises an esterification kettle, a polycondensation kettle and a vacuumizing mechanism, the centers of the bottoms of the esterification kettle and the polycondensation kettle are respectively provided with a discharge valve, the valve port of the discharge valve of the esterification kettle is connected with a delivery pipe, the body of the delivery pipe is provided with a delivery pump, and the delivery pump is connected with a vacuum pump. One end of the conveying pipe is connected with the interior of the polycondensation kettle, the vacuumizing mechanism comprises a temperature sensor, a controller, a vacuum pump, a vacuum degree sensor, a vacuum valve and a vacuum pipe, the temperature sensor is installed on the esterification kettle, a probe of the temperature sensor is arranged in the esterification kettle, and the vacuum degree sensor and the vacuum valve are both installed on the polycondensation kettle. The vacuum degree sensor probe is arranged in the polycondensation kettle, an extraction opening of the vacuum pump is connected with one end of the vacuum pipe, the other end of the vacuum pipe is connected with a valve port of the vacuum valve, the vacuum degree is monitored in real time and automatically adjusted, the vacuum degree in the reaction process is ensured to be stable, and therefore the quality of polyester products is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of reaction kettles, and in particular relates to an automatic vacuum polyester reactor for chemical use. Background Art

[0002] The polyester reaction, or polyester synthesis, refers to the conversion of terephthalic acid (PTA) and ethylene glycol (EG) into polyethylene terephthalate (PET) through esterification and polycondensation. This process is the core step in polyester production, and the final product, PET, is an engineering plastic and polyester film with excellent performance and a wide range of applications.

[0003] During the esterification stage, PTA and EG react to form diethylene terephthalate (BHET). The polycondensation reaction is the process by which BHET removes EG to form long-chain, high-molecular-weight PET. This polycondensation reaction generally requires a catalyst and is carried out under vacuum to promote the reaction toward a high degree of polymerization and increase the reaction rate. The polycondensation reaction is a chain-extending reaction in the polyester synthesis process, and the viscosity and molecular weight of the material gradually reach the required levels during the polycondensation process.

[0004] During the polyester synthesis reaction, the polyester reactor provides suitable reaction conditions and catalysts to promote the reaction. The timing of vacuuming the polyester reactor is crucial to the success of the reaction. Generally speaking, in order to move the reaction towards a high degree of polymerization and increase the reaction speed, the vacuuming operation should be carried out before the start of the polycondensation reaction, while ensuring the purity of the reaction environment and avoiding unnecessary interference. The polyester reactor mainly includes an esterification kettle and a pre-polycondensation kettle, wherein the esterification kettle is mainly used to carry out esterification reaction of the raw materials, which is the basic step of polyester synthesis. Pre-polycondensation kettle: After the esterification reaction, the pre-polycondensation kettle is used to further promote the polymerization of molecules and prepare for the final polycondensation reaction. At present, the polycondensation kettle usually requires manual operation of the vacuum pump for vacuuming, which is cumbersome and inefficient, and cannot guarantee the stability of the vacuum degree, affecting the quality of the polyester product. Therefore, the utility model provides a polyester reactor with automatic vacuuming for chemical use, which can realize the functions of automatic vacuuming and automatic adjustment of the vacuum degree, reduce manual operation and improve work efficiency.

[0005] Currently, no effective solutions have been proposed for the problems in related technologies. Utility Model Content

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a polyester reactor with automatic vacuum pumping for chemical use, comprising an esterification kettle, a polycondensation kettle and a vacuum pumping mechanism, wherein a discharge valve is installed at the center of the bottom of the esterification kettle and the polycondensation kettle, a delivery pipe is connected to the valve port of the discharge valve of the esterification kettle, a delivery pump is installed on the pipe body of the delivery pipe, one end of the delivery pipe is connected to the interior of the polycondensation kettle, the vacuum pumping mechanism comprises a temperature sensor, a controller, a vacuum pump, a vacuum sensor, a vacuum valve and a vacuum tube, the temperature sensor is installed on the esterification kettle, and the temperature sensor probe is placed inside the esterification kettle, the vacuum sensor and the vacuum valve are both installed on the polycondensation kettle, and the vacuum sensor probe is placed in the polycondensation kettle, the vacuum pump exhaust port is connected to one end of the vacuum tube, and the other end of the vacuum tube is connected to the valve port of the vacuum valve.

[0007] As an optimal technical solution of the present invention, the controller is electrically connected to the discharge valve, the delivery pump, the temperature sensor, the vacuum degree sensor of the vacuum pump and the vacuum valve.

[0008] As a preferred technical solution of the present invention, the esterification kettle and the polycondensation kettle both include a kettle body, a kettle cover and an agitator. The kettle body and the kettle cover are fastened together by bolts, and the agitator is mounted on the kettle cover.

[0009] As an optimal technical solution of the present invention, heating elements are installed on the outside of the esterification kettle and the polycondensation kettle, an insulation layer is provided on the outside of the heating elements, and cooling coils are installed on the inside of the kettle bodies of the esterification kettle and the polycondensation kettle.

[0010] As a preferred technical solution of the present invention, the kettle covers are respectively provided with feed ports.

[0011] Compared with existing technologies, the present invention has the following advantages: It utilizes the exothermic phenomenon associated with the esterification reaction, and the characteristic that the temperature tends to stabilize or decrease as the reaction reaches its endpoint. A temperature sensor monitors the temperature changes in the esterification reactor reaction system, thereby determining when to preemptively evacuate the polycondensation reactor. This system has a high degree of automation, with an automatic vacuum pumping mechanism enabling automatic vacuuming and vacuum degree adjustment, reducing manual operation and improving work efficiency. Real-time monitoring and automatic adjustment of the vacuum degree ensure stable vacuum throughout the reaction, thereby improving the quality of the polyester product. A vacuum degree sensor is provided to prevent excessive vacuum, thereby ensuring production safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0013] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0014] Figure 2 It is a schematic cross-sectional structure diagram of the esterification kettle and the polycondensation kettle in the utility model;

[0015] In the figure: 1. Esterification kettle; 2. Polycondensation kettle; 3. Discharge valve; 4. Delivery pipe; 5. Delivery pump; 6. Temperature sensor; 7. Controller; 8. Vacuum pump; 9. Vacuum sensor; 10. Vacuum valve; 11. Vacuum tube; 12. Kettle body; 13. Kettle cover; 14. Agitator; 15. Heating element; 16. Insulation layer; 17. Cooling coil; 18. Feed inlet. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0017] Example

[0018] See also Figure 1-2 The utility model provides the following technical solution: a polyester reactor with automatic vacuum pumping for chemical use, comprising an esterification kettle 1, a polycondensation kettle 2, and a vacuum pumping mechanism. The esterification kettle 1 and the polycondensation kettle 2 are both equipped with a discharge valve 3 at the center of the bottom to facilitate the discharge of materials after the reaction is completed. The discharge valve 3 outlet of the esterification kettle 1 is connected to a conveying pipe 4, on which a conveying pump 5 is installed for conveying materials from the esterification kettle 1 to the polycondensation kettle 2. One end of the conveying pipe 4 is connected to the interior of the polycondensation kettle 2. The vacuum pumping mechanism includes a temperature sensor 6, a controller 7, a vacuum pump 8, a vacuum sensor 9, a vacuum valve 10, and a vacuum tube 11. The temperature sensor 6 is installed on the esterification kettle 1, and its probe is inserted into the interior of the esterification kettle 1 to monitor the reaction temperature in real time. The vacuum sensor 9 and the vacuum valve 10 are installed on the polycondensation kettle 2, and the probe of the vacuum sensor 9 is also inserted into the interior of the polycondensation kettle 2 to monitor the vacuum degree. The exhaust port of the vacuum pump 8 is connected to the vacuum valve 10 via a vacuum tube 11, and the other end of the vacuum tube 11 is connected to the exhaust port of the vacuum pump 8. The controller 7 controls the discharge valve 3, the delivery pump 5, the temperature sensor 6, the vacuum pump 8, the vacuum sensor 9, and the vacuum valve 10 through electrical connections, ensuring automation and precise control of the entire reaction process.

[0019] The structural composition and connection method of the esterification kettle 1 and the polycondensation kettle 2. In this embodiment, as a preferred technical solution of the present invention, the esterification kettle 1 and the polycondensation kettle 2 both include a kettle body 12, a kettle cover 13 and an agitator 14. The kettle body 12 and the kettle cover 13 are fastened together by bolts, and the agitator 14 is installed on the kettle cover 13.

[0020] In order to provide reaction conditions for heating and cooling the esterification kettle 1 and the polycondensation kettle 2, in this embodiment, as a preferred technical solution of the present invention, a heating element 15 is installed on the outside of the kettle body 12 of the esterification kettle 1 and the polycondensation kettle 2, and an insulation layer 16 is provided on the outside of the heating element 15. A cooling coil 17 is installed on the inside of the kettle body 12 of the esterification kettle 1 and the polycondensation kettle 2.

[0021] In order to facilitate feeding, in this embodiment, as a preferred technical solution of the present invention, the kettle cover 13 is respectively equipped with a feeding port 18.

[0022] In summary, with the aid of the above technical solution of the present invention, when in use, PTA and EG are subjected to esterification reaction by the esterification reactor 1 to generate diethylene terephthalate (BHET). During the reaction, there will be heat release. The temperature change in the kettle body 12 of the esterification reactor 1 is monitored by the temperature sensor 6. Once the temperature rise trend slows down to a certain threshold, the temperature information is converted into an electrical signal by the temperature sensor 6 and transmitted to the controller 7. The controller 7 first controls the vacuum valve 10 to open, and at the same time controls the vacuum pump 8 to vacuum the polycondensation reactor 2. The vacuum degree sensor 9 monitors the temperature in the polycondensation reactor 2. When the vacuum degree reaches the threshold value, the information is converted into an electrical signal and transmitted to the controller 7. The controller 7 controls the vacuum pump 8 to close and the vacuum valve 10 to maintain the vacuum in the polycondensation kettle 2. The temperature sensor 6 is used to detect the temperature in the esterification kettle 1. If it tends to be stable or decreases, the controller 7 controls the discharge valve 3 to open, and the delivery pump 5 is used to deliver the reaction product of the esterification kettle 1 to the polycondensation kettle 2 with the help of the delivery pipe 4. The vacuum degree inside the polycondensation kettle 2 is monitored in real time by the vacuum sensor 9. When the vacuum degree does not reach the standard value, the vacuum pumping step is repeated to ensure the vacuum degree in the polycondensation kettle 2.

[0023] Finally, it should be noted that in the present invention, unless otherwise clearly stipulated and limited, terms such as "installation", "setting", "connection", "fixation", and "screw-on" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0024] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A polyester reactor with automatic vacuum pumping for chemical industry, comprising an esterification kettle (1), a polycondensation kettle (2) and a vacuum pumping mechanism, wherein a discharge valve (3) is installed at the center of the bottom of each of the esterification kettle (1) and the polycondensation kettle (2), a delivery pipe (4) is connected to the valve port of the discharge valve (3) of the esterification kettle (1), a delivery pump (5) is installed on the pipe body of the delivery pipe (4), and one end of the delivery pipe (4) is connected to the interior of the polycondensation kettle (2), characterized in that: The vacuum pumping mechanism comprises a temperature sensor (6), a controller (7), a vacuum pump (8), a vacuum sensor (9), a vacuum valve (10) and a vacuum tube (11); the temperature sensor (6) is mounted on the esterification kettle (1), and a probe of the temperature sensor (6) is placed inside the esterification kettle (1); the vacuum sensor (9) and the vacuum valve (10) are both mounted on the polycondensation kettle (2), and the probe of the vacuum sensor (9) is placed inside the polycondensation kettle (2); the air extraction port of the vacuum pump (8) is connected to one end of the vacuum tube (11), and the other end of the vacuum tube (11) is connected to the valve port of the vacuum valve (10).

2. The automatic vacuum-evacuated polyester reactor for chemical industry according to claim 1, characterized in that: The controller (7) is electrically connected to the discharge valve (3), the delivery pump (5), the temperature sensor (6), the vacuum pump (8), the vacuum degree sensor (9) and the vacuum valve (10).

3. The automatic vacuum-evacuated polyester reactor for chemical industry according to claim 1, characterized in that: The esterification kettle (1) and the polycondensation kettle (2) both comprise a kettle body (12), a kettle cover (13) and an agitator (14); the kettle body (12) and the kettle cover (13) are fastened together by bolts, and the agitator (14) is mounted on the kettle cover (13).

4. The automatic vacuum-evacuated polyester reactor for chemical industry according to claim 3, characterized in that: A heating element (15) is installed on the outside of the kettle body (12) of the esterification kettle (1) and the polycondensation kettle (2), and a heat-insulating layer (16) is provided on the outside of the heating element (15). A cooling coil (17) is installed on the inside of the kettle body (12) of the esterification kettle (1) and the polycondensation kettle (2).

5. The automatic vacuum-evacuating polyester reactor for chemical industry according to claim 3, characterized in that: The kettle cover (13) is respectively provided with a material inlet (18).

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