Combined horizontal double-shaft polycondensation reactor
By using a combined horizontal biaxial polycondensation reactor with different stirring paddle structures in different regions, the adhesion problem caused by increased viscosity during PBAT synthesis was solved, and PBAT with higher molecular weight and performance was prepared.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JIANGSU RUIYA MIXING TECH CO LTD
- Filing Date
- 2025-04-25
- Publication Date
- 2026-04-28
AI Technical Summary
In existing PBAT synthesis processes, horizontal single-axis disc reactors are prone to adhesion under high viscosity conditions, which limits film-forming performance and surface renewal performance, making it difficult to prepare high molecular weight and high-performance PBAT.
A combined horizontal biaxial polycondensation reactor is adopted. The low viscosity zone uses an open disc-shaped agitator, the medium viscosity zone uses a rectangular frame structure agitator, and the high viscosity zone uses a mountain-shaped agitator, which gradually enhances the film-forming performance and surface renewal performance along the axial direction.
It improves the film-forming performance and surface renewal performance of the reactor, adapts to the gradual increase in system viscosity, and enhances the molecular weight and performance of PBAT.
Smart Images
Figure CN224167511U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of polycondensation reactor technology, and in particular to a combined horizontal biaxial polycondensation reactor. Background Technology
[0002] Condensation polymerization (PPG) refers to the process by which difunctional and / or polyfunctional monomers combine multiple times to form high molecular weight polymers, with small molecule compounds generated during the reaction. Polyesters (PET), poly(butylene adipic acid / terephthalate) (PBAT), polyamides, polycarbonates (PC), polyimides, and polysulfones are all prepared through PPG reactions.
[0003] Common polycondensation methods include melt polycondensation, solid-state polycondensation, interfacial polycondensation, and solution polycondensation. Most polyesters and polyamides use melt polycondensation, which has the following characteristics: (1) The viscosity of the reaction system is very high and increases sharply as the polycondensation process proceeds; (2) The reaction temperature is high, and the pressure or high vacuum is required in the later stage of the reaction; (3) The polycondensation reaction is a reversible equilibrium reaction with a small equilibrium constant, and the generated small molecules must be released in time.
[0004] Polybutylene terephthalate (PBAT) is 100% biodegradable and is currently the most promising and popular petroleum-based biodegradable copolyester. It boasts advantages such as high elongation at break, good flexibility, and ease of large-scale production, making it suitable for various applications including packaging materials, hygiene products, biomedicine, and industrial composting. The main synthesis methods for PBAT are direct esterification and transesterification. Currently, industrialized production technologies all utilize the direct esterification process. Direct esterification of PBAT primarily uses 1,4-butanediol (BDO), adipic acid (AA), and terephthalic acid (PTA) as raw materials, directly undergoing esterification and polycondensation reactions under the action of a catalyst. The direct esterification process includes pulping, esterification, pre-polymerization, and final polycondensation.
[0005] The polycondensation process of PBAT is extremely critical. The system has high viscosity, which continues to increase as the reaction proceeds, and small molecules are generated. These small molecules need to be removed from the system in a timely manner for the molecular weight of PBAT to increase further. Currently, the final polycondensation reactor for PBAT is mainly a horizontal single-shaft disc reactor. As the viscosity of the polymer melt further increases, adhesion occurs between the discs, which greatly limits the film-forming performance and surface renewal performance of the reactor, making it difficult to prepare PBAT with higher molecular weight and higher performance. Utility Model Content
[0006] This invention solves the problems in related technologies and proposes a combined horizontal biaxial polycondensation reactor. The low viscosity zone uses an open-hole disc-shaped stirring paddle, the medium viscosity zone uses a rectangular frame structure stirring paddle, and the high viscosity zone uses a mountain-shaped stirring paddle. This makes the film-forming performance and surface renewal performance of the reactor gradually enhanced along the axial direction, thus better adapting to the gradual increase of the system viscosity during the polycondensation process.
[0007] To solve the above-mentioned technical problems, this utility model is achieved through the following technical solution: a combined horizontal biaxial polycondensation reactor, including a vessel body and a stirrer; the vessel body is provided with a material inlet, a material outlet and a devolatilization port, and the vessel body is divided into a low viscosity zone, a medium viscosity zone and a high viscosity zone from the material inlet to the material outlet; the stirrer includes two stirring shafts and stirring paddles installed on the stirring shafts; the stirring paddles include a low viscosity zone stirring paddle, a medium viscosity zone stirring paddle and a high viscosity zone stirring paddle; the low viscosity zone stirring paddle is an open disc shape, the medium viscosity zone stirring paddle is a rectangular frame, and the high viscosity zone stirring paddle has a mountain-shaped structure.
[0008] As a preferred embodiment, the low-viscosity zone stirring impellers are arranged alternately along the axial direction, the window area has a fan-shaped structure, and the number of windows is 2 to 6.
[0009] As a preferred embodiment, the two rectangular frames of the medium-viscosity zone stirring paddle connected end to end in the axial direction have an included angle of 90°, and the rectangular frames on the two stirring shafts in the radial direction are arranged in parallel.
[0010] As a preferred embodiment, the high viscosity zone stirring paddle is composed of mountain-shaped kneading elements, the number of which is 2 to 8, and the high viscosity zone stirring paddle is arranged alternately along the axial direction.
[0011] As a preferred embodiment, the phase angle of the corresponding impellers on the two stirring shafts is 45°.
[0012] As a preferred embodiment, the two stirring shafts rotate in opposite directions and at the same stirring speed.
[0013] Compared with the prior art, the beneficial effects of this utility model are as follows: The stirring paddle of this utility model is divided into three regions, and the stirring paddle structure of each region is different. The low viscosity region adopts an open disc-shaped stirring paddle, the medium viscosity region adopts a rectangular frame structure stirring paddle, and the high viscosity region adopts a mountain-shaped stirring paddle. This makes the film-forming performance and surface renewal performance of the reactor gradually enhanced along the axial direction, thereby better adapting to the gradual increase of the system viscosity during the polycondensation process. Attached Figure Description
[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model;
[0015] Figure 2This is a schematic diagram of the structure of the stirrer of this utility model;
[0016] Figure 3 This is a schematic diagram of the structure of the stirrer of this utility model.
[0017] In the picture:
[0018] 1. Kettle body; 2. Agitator; 21. Agitator shaft; 22. Agitator paddle; 221. Agitator paddle for low viscosity zone; 222. Agitator paddle for medium viscosity zone; 223. Agitator paddle for high viscosity zone; 3. Material inlet; 4. Material outlet; 5. Volatilization outlet. Detailed Implementation
[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present utility model or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.
[0020] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0021] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values of the components and steps described in these embodiments do not limit the scope of this invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.
[0022] In the description of this utility model, it should be understood that the directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this utility model. The directional terms "inner" and "outer" refer to the inner and outer contours of each component itself.
[0023] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.
[0024] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this utility model.
[0025] like Figures 1 to 3 As shown, a combined horizontal biaxial polycondensation reactor includes a vessel body 1 and a stirrer 2. The vessel body 1 is provided with a material inlet 3, a material outlet 4, and a devolatilization port 5. The material inlet 3 is used for feeding, the material outlet 4 is used for discharging, and the devolatilization port 5 facilitates the removal of small molecule by-products generated during the reaction, thereby improving product quality. The vessel body 1 is divided into a low-viscosity zone, a medium-viscosity zone, and a high-viscosity zone from the material inlet 3 to the material outlet 4. The stirrer 2 includes two stirring shafts 21 and stirring paddles 22 mounted on the stirring shafts 21. The stirring paddles 22 on the two stirring shafts 21 are staggered along the axial direction. Different structures of stirring paddles 22 are used for the three zones in the vessel body 1. That is, the stirring paddles 22 include a low-viscosity zone stirring paddle 221, a medium-viscosity zone stirring paddle 222, and a high-viscosity zone stirring paddle 223. The low-viscosity zone stirring paddle 221 is an open disc shape, the medium-viscosity zone stirring paddle 222 is a rectangular frame, and the high-viscosity zone stirring paddle 223 is a mountain-shaped structure.
[0026] In one embodiment, the low-viscosity zone impellers 221 are arranged alternately along the axial direction, and the window area has a fan-shaped structure with a total of 4 windows.
[0027] In one embodiment, the two rectangular frames of the medium-viscosity zone stirring paddle 222 connected end to end in the axial direction have an included angle of 90°, and the rectangular frames on the two stirring shafts 21 are arranged in parallel in the radial direction.
[0028] In one embodiment, the high viscosity zone stirring paddle 223 is composed of four mountain-shaped kneading elements, which are arranged alternately along the axial direction.
[0029] In one embodiment, the phase angle of the corresponding impellers 22 on the two stirring shafts 21 is 45°.
[0030] In one embodiment, the two stirring shafts 21 rotate in opposite directions and at the same stirring speed.
[0031] The above are preferred embodiments of this utility model. Those skilled in the art can make changes and modifications to the above embodiments. Therefore, this utility model is not limited to the specific embodiments described above. Any obvious improvements, substitutions or modifications made by those skilled in the art based on this utility model shall fall within the protection scope of this utility model.
Claims
1. A combined horizontal biaxial polycondensation reactor, characterized in that: The apparatus includes a vessel body (1) and a stirrer (2). The vessel body (1) is provided with a material inlet (3), a material outlet (4), and a volatilization port (5). The vessel body (1) is divided into a low viscosity zone, a medium viscosity zone, and a high viscosity zone from the material inlet (3) to the material outlet (4). The stirrer (2) includes two stirring shafts (21) and stirring paddles (22) mounted on the stirring shafts (21). The stirring paddles (22) include a low viscosity zone stirring paddle (221), a medium viscosity zone stirring paddle (222), and a high viscosity zone stirring paddle (223). The low viscosity zone stirring paddle (221) is a perforated disc shape, the medium viscosity zone stirring paddle (222) is a rectangular frame, and the high viscosity zone stirring paddle (223) is a mountain-shaped structure.
2. The combined horizontal biaxial polycondensation reactor according to claim 1, characterized in that: The low-viscosity stirring paddles (221) are arranged alternately along the axial direction, and the window area has a fan-shaped structure with 2 to 6 windows.
3. The combined horizontal biaxial polycondensation reactor according to claim 1, characterized in that: The two rectangular frames of the medium viscosity zone stirring paddle (222) are connected end to end in the axial direction with an included angle of 90°, and the rectangular frames on the two stirring shafts (21) are arranged in parallel in the radial direction.
4. The combined horizontal biaxial polycondensation reactor according to claim 1, characterized in that: The high viscosity zone stirring paddle (223) is composed of mountain-shaped kneading elements, the number of which is 2 to 8, and the high viscosity zone stirring paddle (223) is arranged alternately along the axial direction.
5. The combined horizontal biaxial polycondensation reactor according to claim 1, characterized in that: The phase angle of the corresponding impellers (22) on the two stirring shafts (21) is 45°.
6. The combined horizontal biaxial polycondensation reactor according to claim 1, characterized in that: The two stirring shafts (21) rotate in opposite directions and at the same stirring speed.