Efficient and energy-saving continuous polyester production device

Abstract

The utility model provides an efficient and energy-saving continuous polyester production device which comprises a raw material input pipeline, a polymerization unit and a product output pipeline which are sequentially arranged, the production device further comprises a heat exchanger, and the raw material input pipeline and the product output pipeline both pass through the heat exchanger. According to the continuous polyester production device provided by the utility model, the raw material input pipeline and the product output pipeline exchange heat through the heat exchanger, waste heat of high-temperature products in continuous polyester production is utilized to continuously heat raw materials, the fed liquid raw materials are heated while continuous cooling of the products is realized, and secondary energy is effectively utilized; and by utilizing the characteristic that the polyol raw material is generally polar molecules, the molecules are heated in a more energy-saving microwave mode, so that the energy is further saved, and the energy consumption of a polyester production device is reduced.

Description

Technical Field

[0001] This utility model relates to a polymer material production device, specifically to a high-efficiency and energy-saving continuous polyester production device. Background Technology

[0002] Polyester, as an important polymer material, plays a vital role in many areas of modern industry and daily life. For example, polyester film, with its excellent barrier properties, mechanical strength, and good optical properties, is widely used in the packaging industry; clothing made from polyester fibers has advantages such as crispness, wrinkle resistance, easy washing, and quick drying, and is widely used in the textile industry; polyester resin can be used to manufacture insulating components and casings, and is also widely used in electronics and electrical appliances. In addition to polyester plastics, polyester polyols can be used as raw materials for polyurethane, and are widely used in polyurethane elastomers, polyurethane fibers, and foamed polyurethane.

[0003] Currently, the traditional continuous process used in polyester production consumes a huge amount of energy, especially in core reaction stages such as esterification and polycondensation. On the one hand, the products after high-temperature reaction need to be cooled down, and the large amount of heat energy contained in this process is usually not effectively recovered and is directly or indirectly released into the environment, resulting in serious energy waste. On the other hand, the raw materials that will participate in the reaction, such as various liquid raw materials, need to be heated from a lower temperature to a suitable reaction temperature, which requires additional consumption of a large amount of electricity, heat and other energy to meet this demand, making the overall energy cost of the entire production process high. Utility Model Content

[0004] To address the aforementioned problems, this utility model provides a highly efficient and energy-saving continuous polyester production device, aiming to reduce energy consumption during polyester production. The specific solution is as follows:

[0005] A high-efficiency and energy-saving continuous polyester production apparatus includes a raw material input pipeline, a polymerization unit, and a product output pipeline arranged in sequence. The apparatus is characterized in that it further includes a heat exchanger, and both the raw material input pipeline and the product output pipeline pass through the heat exchanger.

[0006] Furthermore, the heat exchanger is one or more of a tubular heat exchanger, a plate heat exchanger, or a heat transfer medium heat exchanger.

[0007] Furthermore, the polymerization unit includes an esterification unit and a polycondensation unit arranged sequentially, the esterification unit including at least one reactor, and the polycondensation unit including at least one reactor.

[0008] Furthermore, the esterification unit includes a first esterification vessel and a second esterification vessel, the first esterification vessel being equipped with a self-circulating system, and the self-circulating system being equipped with a microwave heating unit.

[0009] Furthermore, the microwave heating unit is a box-type heating unit, including a microwave generator, a microwave radiator, a microwave reaction cavity, a microwave shielding structure, etc.

[0010] Furthermore, the microwave reaction cavity in the microwave heating unit is equipped with a gas outlet connected to the first esterification vessel.

[0011] Furthermore, the reaction chamber within the microwave heating unit is made of a microwave-transparent material, such as heat-resistant glass, tetrafluoroethylene, polypropylene ether ketone, quartz, or alumina ceramic.

[0012] Beneficial effects:

[0013] The continuous polyester production apparatus provided by this utility model allows for heat exchange between the raw material input pipeline and the product output pipeline via a heat exchanger. The heat source of the high-temperature product in continuous polyester production is used to continuously heat the raw material, achieving continuous cooling of the product while simultaneously heating the fed liquid raw material, effectively utilizing secondary energy. Furthermore, taking advantage of the characteristic that polyol raw materials are typically polar molecules, a more energy-efficient microwave method is used to directly heat the molecules, further saving energy and reducing the energy consumption of the polyester production apparatus. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the process flow of the high-efficiency and energy-saving continuous polyester production device of this utility model.

[0015] Figure 2 This is a schematic diagram of the process flow of the high-efficiency and energy-saving continuous polyester polyol production device of this utility model.

[0016] Explanation of reference numerals in the attached figures

[0017] 1. Liquid raw material storage tank 2. Raw material input pipeline 3. Feed port 4. First esterification reactor 5. First transfer pump 6. Microwave heating unit 7. Second esterification reactor 8. Second transfer pump 9. Prepolymerization reactor 10. Third transfer pump 11. Final polymerization reactor 12. Fourth transfer pump 13. Filtration and granulation unit 14. Product storage tank 15. Product output pipeline 16. Heat exchanger Detailed Implementation

[0018] In traditional polyester production processes, a large amount of heat is consumed during the heating of raw materials, and a large amount of heat is wasted during the cooling of the product. To solve the above problems, this utility model provides a highly efficient and energy-saving continuous polyester production device.

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be further described clearly and completely below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. For clarity and brevity, not all features of the actual implementation are described in the specification. However, it should be understood that many implementation-specific decisions must be made in the development of any such actual embodiment to achieve the developer's specific goals. To avoid obscuring the utility model with unnecessary details, only the device structures closely related to the solutions according to this utility model are described in the drawings and description. To more clearly show the structure of the device described in this utility model, some structures are omitted in the drawings to highlight the feature structures indicating important parts.

[0020] Example 1

[0021] This embodiment provides a highly efficient and energy-saving continuous polyester production apparatus. For example... Figure 1 The polyester production apparatus includes a liquid raw material storage tank 1, a raw material input pipeline 2, a polymerization unit, a product output pipeline 15, and a filtration and granulation unit 13 arranged sequentially. Furthermore, the polyester production apparatus also includes a heat exchanger 16. The polymerization unit includes a first esterification reactor 4, a second esterification reactor 7, a pre-condensation reactor 9, and a final condensation reactor 11. The liquid raw material storage tank 1 is connected to the polymerization unit via the raw material input pipeline 2, and the filtration and granulation unit 13 is connected to the polymerization unit via the product output pipeline 15. The input raw material and the output product exchange heat in the heat exchanger 16. The heat exchanger 16 transfers the heat from the high-temperature polyester product in the product output pipeline 15 to the low-temperature raw material. In this embodiment, the heat exchanger 16 is a tubular heat exchanger. In this embodiment, the raw material ethylene glycol in the raw material input pipeline 2 and the polyester product in the product output pipeline 15 exchange heat in the heat exchanger 16, cooling the polyester product while heating the raw material ethylene glycol, thus achieving the purpose of heat exchange.

[0022] A first transfer pump 5 is installed between the first esterification vessel 4 and the second esterification vessel 7; a second transfer pump 8 is installed between the second esterification vessel 7 and the polycondensation vessel 9; a third transfer pump 10 is installed between the pre-polycondensation vessel 9 and the final polycondensation vessel 11; and a fourth transfer pump 12 is installed between the final polycondensation vessel 11 and the heat exchanger 16. The first esterification vessel 4 is equipped with a feeding port 3 for adding other materials. The pipeline after the first transfer pump 5 is divided into two paths: one is a self-circulating microwave heating pipeline leading to the upper end of the first esterification vessel 4, and a microwave heating unit 6 is installed in this circulation pipeline. The microwave heating unit 6 is a box-type heating unit, including a microwave generator, a microwave radiator, a microwave reaction cavity, and a microwave shielding structure for the box. The term "box-type" refers to the heating unit having a shielding structure that encloses the microwave-related equipment to improve equipment safety. The microwave reaction cavity has a gas outlet connected to the first esterification vessel to prevent the product (such as water) from overheating and boiling, or the reaction liquid from vaporizing when overheated, which could affect the equipment. The microwave reaction cavity is made of a microwave-transparent material, allowing the material to be microwave-heated while passing through the microwave heating unit 6. A portion of the material in the first esterification vessel 4 is continuously fed to the second esterification vessel 7 via another path after the transfer pump 5.

[0023] The working process of the polyester production apparatus in this embodiment is as follows: Taking PET production as an example, during the production process, liquid raw material ethylene glycol enters the first esterification reactor 4 from the liquid raw material storage tank 1 through the raw material input pipeline 2. The liquid raw material ethylene glycol is stored at room temperature in the liquid raw material storage tank 1. During the transportation of ethylene glycol through the raw material input pipeline 2, it passes through the heat exchanger 16. When the ethylene glycol is transported in the heat exchanger 16, it absorbs the heat released by the high-temperature polyester product and rises in temperature. After being heated, the ethylene glycol leaves the heat exchanger 16 and enters the first esterification reactor 4 through the raw material input pipeline 2. PTA and other materials enter the first esterification reactor 4 through the other materials feed port 3. Ethylene glycol and PTA undergo esterification in the first esterification reactor 4. The materials in the first esterification reactor 4 are divided into two paths by the first transfer pump 5. One path is a self-circulating pipeline of the esterification system, which returns to the upper part of the first esterification reactor 4 through the microwave heating unit 6. The microwave generator in the microwave heating unit 6 generates microwaves, and the microwave radiator transmits the microwave energy to the microwave reaction cavity, ensuring that the materials in the microwave reaction cavity are fully and uniformly heated under the action of microwave energy. The microwave shielding structure of this unit is used to prevent microwave leakage into the surrounding environment, ensuring the health of operators and the normal operation of surrounding electronic equipment. The materials heated by the microwave heating unit 6 return to the first esterification reactor 4 for continuous esterification. After the initial esterification reaction, while the materials in the first esterification reactor 4 continue to circulate and undergo esterification, a portion of the materials in the first esterification reactor 4 is continuously transported to the second esterification reactor 7 through another pipeline after the first transfer pump 5. The material in the second esterification reactor 7 undergoes further esterification. After esterification, the material leaves the second esterification reactor 7 through a pipeline and is continuously transferred to the pre-polymerization reactor 9 by the second transfer pump 8 for pre-polymerization. After pre-polymerization, the material in the pre-polymerization reactor 9 is transferred to the final polymerization reactor 11 by the third transfer pump 10 for further polymerization. After final polymerization, the material in the final polymerization reactor 11 yields a qualified polyester melt product. This polyester product leaves the final polymerization reactor 11 through the product transfer pipe 15, passes through the fourth transfer pump 12, and is cooled by the heat exchanger 16 before continuously flowing to the product filtration and granulation unit 13.

[0024] The polyester product exiting the final polycondensation reactor 11 is still at a high temperature and requires cooling. During its transport in the product output pipe 15, the polyester product passes through the heat exchanger 16. In the heat exchanger 16, the polyester product in the product output pipe 15 undergoes thorough heat exchange with the room-temperature ethylene glycol material in the raw material input pipe 2. While the polyester product cools down, the ethylene glycol raw material is also heated. This saves energy consumption for both cooling the polyester product and heating the ethylene glycol, utilizing the waste heat of the product and reducing the overall energy consumption of the equipment.

[0025] Example 2

[0026] This embodiment provides a highly efficient and energy-saving continuous polyester polyol production apparatus. For example... Figure 2 The polyester polyol production apparatus includes a liquid raw material storage tank 1, a raw material input pipeline 2, a polymerization unit, a product output pipeline 15, and a product storage tank 14, arranged sequentially. Furthermore, the apparatus also includes a heat exchanger 16. The polymerization unit includes a first esterification reactor 4, a second esterification reactor 7, and a polycondensation reactor 9. The liquid raw material storage tank 1 is connected to the polymerization unit via the raw material input pipeline 2, and the product storage tank 14 is connected to the polymerization unit via the product output pipeline 15. The input raw material and the output product exchange heat in the heat exchanger 16. The heat exchanger 16 transfers the heat from the high-temperature polyester polyol product in the product output pipeline 15 to the low-temperature raw material in the raw material input pipeline 2. In this embodiment, the heat exchanger 16 is a plate heat exchanger. In this embodiment, the raw material ethylene glycol in the raw material input pipeline 2 and the polyester polyol product in the product output pipeline 15 pass through the heat exchanger 16, where the polyester polyol product is cooled while the raw material ethylene glycol is heated, achieving the purpose of heat exchange.

[0027] A first transfer pump 5 is installed between the first esterification vessel 4 and the second esterification vessel 7; a second transfer pump 8 is installed between the second esterification vessel 7 and the polycondensation vessel 9; and a third transfer pump 10 is installed between the polycondensation vessel 9 and the heat exchanger 16. The first esterification vessel 4 is equipped with a feeding port 3 for adding other materials. The pipeline after the first transfer pump 5 is divided into two paths: one is a self-circulating microwave heating pipeline leading to the upper end of the first esterification vessel 4, and a microwave heating unit 6 is installed in this circulation pipeline. The microwave heating unit 6 is a box-type heating unit, including a microwave generator, a microwave radiator, a microwave reaction cavity, and a microwave shielding structure for the box. The term "box-type" refers to the shielding structure that surrounds the microwave-related equipment in the heating unit to improve equipment safety. The microwave reaction cavity has a gas outlet connected to the first esterification vessel to prevent the product (such as water) from overheating and boiling, or the reaction liquid from vaporizing when overheated, which could affect the equipment. The reaction cavity is made of a microwave-transparent material so that the material is microwave-heated while passing through the microwave heating unit 6. A portion of the material in the first esterification vessel 4 is transferred to the second esterification vessel 7 via another path after the transfer pump 5.

[0028] The working process of the polyester polyol production device in this embodiment is as follows: Taking the production of polyethylene adipate diol as an example, during the production process, liquid raw material ethylene glycol enters the first esterification reactor 4 from the liquid raw material storage tank 1 through the raw material input pipeline 2. The liquid raw material ethylene glycol is stored at room temperature in the liquid raw material storage tank 1. During the transportation of ethylene glycol through the raw material input pipeline 2, it passes through the heat exchanger 16. When the ethylene glycol is transferred in the heat exchange unit, it absorbs the heat released by the high-temperature polyester polyol and its temperature rises. After being heated, the ethylene glycol leaves the heat exchanger 16 and enters the first esterification reactor 4 through the raw material input pipeline 2. Other materials such as adipic acid enter the first esterification reactor 4 through the other material feeding port 3. Ethylene glycol and other materials such as adipic acid undergo esterification reaction in the first esterification reactor 4. In this process, the material in the first esterification reactor 4 is divided into two paths by the first transfer pump 5. One path is a self-circulating pipeline of the esterification system, which flows back to the upper end of the first esterification reactor 4 through the microwave heating unit 6. The microwave generator in the microwave heating unit 6 generates microwaves, and the microwave radiator transmits the microwave energy to the microwave reaction cavity, allowing the material in the microwave reaction cavity to be fully and uniformly heated under the action of microwave energy. The microwave shielding structure of this unit is used to prevent microwave leakage into the surrounding environment, ensuring the health of the operators and the normal operation of the surrounding electronic equipment. The material heated by the microwave heating unit 6 flows back to the first esterification reactor 4 and continues to circulate for the esterification reaction. After the initial esterification reaction, while the material in the first esterification reactor 4 continues to circulate for the esterification reaction, a portion of the material in the first esterification reactor 4 is continuously transported to the second esterification reactor 7 through another pipeline after the first transfer pump 5. The material in the second esterification reactor 7 undergoes further esterification reaction. After esterification, the material leaves the second esterification reactor 7 through a pipeline and is continuously transferred to the polycondensation reactor 9 by the second transfer pump 8 for polycondensation reaction. After polycondensation, the material in the polycondensation reactor 9 yields qualified polyester polyol. The polyester polyol product leaves the final polycondensation reactor 9 through the product transfer pipe 15. After passing through the third transfer pump 10, the polyester polyol product is cooled by the heat exchanger 16 and then continuously flows into the product storage tank 14.

[0029] The polyester polyol product exiting the polycondensation reactor 9 is still at a high temperature and requires cooling. During its transport in the product output pipe 15, the polyester polyol product passes through the heat exchanger 16. In the heat exchanger 16, the polyester polyol product in the product output pipe 15 undergoes thorough heat exchange with the room-temperature ethylene glycol material in the raw material input pipe 2. While the polyester polyol product cools down, the ethylene glycol raw material is also heated up. This saves energy consumption for both cooling the polyester polyol product and heating the ethylene glycol, utilizing the waste heat of the product and reducing the overall energy consumption of the equipment.

Claims

1. A high-efficiency and energy-saving continuous polyester production apparatus, comprising a raw material input pipe, a polymerization unit, and a product output pipe arranged sequentially, characterized in that, The production apparatus also includes a heat exchanger, through which both the raw material input pipeline and the product output pipeline pass.

2. The continuous polyester production apparatus according to claim 1, characterized in that, The heat exchanger is one or more of the following: tubular heat exchanger, plate heat exchanger, or heat transfer medium heat exchanger.

3. The continuous polyester production apparatus according to claim 1, characterized in that, The polymerization unit includes an esterification unit and a polycondensation unit arranged sequentially. The esterification unit includes at least one reactor, and the polycondensation unit includes at least one reactor.

4. The continuous polyester production apparatus according to claim 3, characterized in that, The esterification unit includes a first esterification vessel and a second esterification vessel. The first esterification vessel is equipped with a self-circulation system, and the self-circulation system is equipped with a microwave heating unit.

5. The continuous polyester production apparatus according to claim 4, characterized in that, The microwave heating unit is a box-type heating unit, including a microwave generator, a microwave radiator, a microwave reaction cavity, a microwave shielding structure, etc.

6. The continuous polyester production apparatus according to claim 5, characterized in that, The microwave reaction chamber in the microwave heating unit is equipped with a gas outlet connected to the first esterification vessel.

7. The continuous polyester production apparatus according to claim 5, characterized in that, The reaction chamber inside the microwave heating unit is made of a wave-transparent material.

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