A polyester final polycondensation reactor

Abstract

This utility model belongs to the field of chemical equipment technology, specifically relating to a polyester final polycondensation reactor. The utility model includes: a cylindrical body with an inlet and an outlet at its lower ends, and an exhaust port above the outlet; a stirring shaft disposed within the cylindrical body, on which are arranged several discs, each disc having several scrapers evenly distributed on its outer circumference; and several dividing plates disposed inside the upper part of the cylindrical body, extending at intervals between the discs. This utility model addresses the technical problems of existing disc reactors in producing high-viscosity products, such as poor stirring effect, difficulty in pushing material along the cylinder wall, and low relative material movement between the discs, leading to decreased reaction efficiency and product quality.

Description

Technical Field

[0001] This utility model belongs to the field of chemical equipment technology, and specifically relates to a polyester final polycondensation reactor. Background Technology

[0002] Currently in the domestic polyester industry, when producing low-viscosity products (maximum intrinsic viscosity 0.75 dL / g, corresponding dynamic viscosity ≤300 Pa·s at different product operating temperatures) using conventional polyesters such as PET and PBT, disc reactors are typically used in the final polycondensation reaction stage. These reactors offer good film formation, high heat and mass transfer efficiency, large melt flow channels, and high production capacity. However, when producing high-viscosity products, ordinary disc reactors encounter the following problems: 1. As viscosity increases, the thickness of the melt on the disk increases, which causes the material between the disks to stick together. This makes the material relatively stationary with respect to the disk, preventing the subsequent replacement of material and thus significantly reducing the reaction efficiency. 2. As viscosity increases, the melt flowability at the edge of the disc reactor cylinder decreases, making it unable to form a film and participate in the reaction; 3. Insufficient mixing after the fluid enters the reactor reduces the fluid's propulsion towards the outlet, resulting in uneven heat exchange and making the product prone to localized degradation and discoloration. Utility Model Content

[0003] This invention provides a polyester final polycondensation reactor to solve the technical problems of poor stirring effect, difficulty in pushing material on the cylinder wall, and low relative movement of material between discs in the production of high viscosity products in the prior art disc reactors, which lead to a decrease in both reaction efficiency and product quality.

[0004] This utility model includes: a cylindrical body, with a feed inlet and a discharge outlet respectively provided at its lower two ends, and an exhaust outlet provided above the discharge outlet; A stirring shaft is provided inside the cylinder, and a number of discs are provided on the stirring shaft. A number of scrapers are evenly distributed on the outer circumferential surface of each disc. Several dividing plates are disposed above the interior of the cylinder and extend at intervals between the several disks.

[0005] In this invention, the scraper can scrape the high-viscosity material on the inner wall of the cylinder to prevent the material from not flowing, and the dividing plate can solve the problem of material sticking between adjacent discs. By using the scraper and the dividing plate in combination, a better cutting and stirring effect can be achieved for high-viscosity materials.

[0006] Furthermore: the disk includes a central tube and an annular plate, and the central tube and the annular plate are connected by a number of evenly distributed spokes. The beneficial effect of this step is that the through holes between the spokes allow material to flow through, which can increase the material flow path.

[0007] Furthermore, the number of scrapers on each of the discs is 4 to 12; The included angle between the scraper and the disc ranges from 15° to 75°, and the included angle between the disc and the scraper gradually decreases along the direction from the feed inlet to the discharge outlet. The beneficial effect of this step is that by adjusting the scraper angle, the material feeding speed can be controlled. That is, by adjusting the included angle of the scraper to be different at different positions, an angle difference is formed, so that the feeding speed of the material at different positions is also different, thereby controlling the residence time of the material in the cylinder.

[0008] Furthermore, the scrapers on adjacent discs are staggered. The beneficial effect of this step is that the staggered scrapers can alternately contact the material on the cylinder wall, rather than contacting the material on the cylinder wall simultaneously in a straight line. Under the action of the staggered scrapers, the material can be better stirred.

[0009] Furthermore, the cross-sectional shape of the scraper is square, willow leaf-shaped, or wedge-shaped. The beneficial effects of this step are: the willow leaf shape is large in the middle and pointed at both ends, and the wedge shape is pointed at the front end and thick at the rear end. Both of these shapes are easy to insert into the material and have good guiding properties, while the pointed end of the willow leaf shape is easier to separate from the material.

[0010] Furthermore, the distance between adjacent dividing plates gradually increases along the direction from the feed inlet to the discharge outlet. The beneficial effect of this step is that as the reaction continues, the viscosity of the material increases closer to the discharge outlet, and the material between the discs is more likely to stick together. More and denser dividing plates are needed to separate as much material as possible from the discs.

[0011] Furthermore: the dividing plate is fan-shaped, the arc edge of the dividing plate is connected to the cylinder, any straight edge of the dividing plate is connected to the bracket, and both ends of the bracket are connected to the cylinder. The beneficial effect of this step is that the bracket strengthens the installation structure of the dividing plate and prevents the dividing plate from separating from the cylinder wall.

[0012] The beneficial effects of this utility model are: This invention overcomes the problems of high-viscosity products sticking to the disc during stirring, reducing reaction efficiency, decreasing melt flow on the inner wall of the reactor, preventing film formation and residual reaction, and insufficient mixing by setting a scraper on the stirring shaft disc and a dividing plate on the inner wall of the reactor. This allows the original reactor to produce both low-viscosity and high-viscosity products, thus expanding the reactor's application range. Attached Figure Description

[0013] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0014] Figure 1 A cross-sectional perspective view of a polyester final polycondensation reactor provided for this utility model; Figure 2 A cross-sectional structural schematic diagram of a polyester final polycondensation reactor provided by this utility model; Figure 3 A cross-sectional structural diagram of the cylindrical body of a polyester final polycondensation reactor provided by this utility model; Figure 4 A perspective view of a disc in a polyester final polycondensation reactor provided by this utility model; Figure 5 This is a schematic diagram of the assembly structure of the dividing plate in a polyester final polycondensation reactor provided by this utility model.

[0015] Figure label: 1-Cylinder body; 2-Stirring shaft; 11-Inlet; 12-Outlet; 13-Exhaust port; 14-Divider plate; 15-Support; 21-Disc; 22-Scraper; 211-Central tube; 212-Ring plate; 213-Spoke plate. Detailed Implementation

[0016] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the present invention and should not be construed as limiting the scope of protection of the present invention. It should be noted that, unless otherwise stated, the technical or scientific terms used in this application shall have the ordinary meaning as understood by one of ordinary skill in the art to which this utility model pertains.

[0017] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and are not intended to 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 of this utility model.

[0018] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly defined.

[0019] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0020] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0021] Implementation of this application, for example Figures 1-5 As shown, this application provides a polyester final polycondensation reactor.

[0022] In the fields of chemical engineering and new materials, this involves polymerization technology and polyester products, including but not limited to PET (polyethylene terephthalate), PBT (polybutylene terephthalate), PBS (polybutylene succinate), PBAT (polybutylene terephthalate), TPEE (thermoplastic polyester elastomer), PETG / PCTG (polyethylene glycol terephthalate-1,4-cyclohexanediol ester), etc.

[0023] This application includes: a cylinder 1, with an inlet 11 and an outlet 12 at its lower ends, and an exhaust port 13 above the outlet 12, which is used to discharge the gas generated by the material during the reaction. A stirring shaft 2 is located inside the cylinder 1. Several discs 21 are provided on the stirring shaft 2, and several scrapers 22 are evenly distributed on the outer circumferential surface of each disc 21. Several dividing plates 14 are disposed above the interior of the cylinder 1 and extend at intervals between several of the discs 21.

[0024] In this application, the scraper 22 can scrape the high-viscosity material on the inner wall of the cylinder 1 to prevent the material from not flowing, and the dividing plate 14 can solve the problem of material sticking between adjacent discs 21. By using the combination of scraper 22 and dividing plate 14, a better cutting and stirring effect can be achieved for high-viscosity materials.

[0025] This application enables the production of polyester products with an intrinsic viscosity of 1.0 dL / g and a dynamic viscosity of over 300 Pa·s at different product operating temperatures. This allows disc reactors to be used normally in the production of high-viscosity polyesters, and even copolyesters such as PBAT (polybutylene terephthalate), TPEE (thermoplastic polyester elastomer), PETG / PCTG (polyethylene glycol terephthalate-1,4-cyclohexanediol ester), thus expanding the application range of disc reactors.

[0026] Based on the above technical solution, the disc 21 includes a central tube 211 and an annular plate 212. The central tube 211 and the annular plate 212 are connected by a number of evenly distributed spokes 213. The central tube 211 can be sleeved on the shaft of the stirring shaft 2. The length of the central tube 211 is the distance between the discs 21. During the production process of the stirring shaft 2, adjacent central tubes 211 abut against each other, which can determine the distance between the discs 21, enabling quick and easy positioning. The through holes between the annular plate 212, the central tube 211 and the spokes 213 allow material to flow, which can increase the material flow path.

[0027] Based on the above technical solution, the number of scrapers 22 on each of the discs 21 is 4 to 12, and the number of scrapers 22 is preferably an even number; The scraper 22 and the disc 21 have an included angle range α of 15° to 75°, and the included angle between the disc 21 and the scraper 22 gradually decreases along the direction from the feed inlet 11 to the discharge outlet 12. By adjusting the angle of the scraper 22, the material pushing speed is controlled. That is, by adjusting the included angle of the scraper 22 to be different at different positions, an angle difference is formed, so that the pushing speed of the material at different positions is also different, thereby controlling the residence time of the material in the cylinder 1.

[0028] Based on the above technical solution, the scrapers 22 on adjacent discs 21 are staggered. The staggered scrapers 22 can alternately contact the material on the cylinder wall, rather than contacting the material on the cylinder wall simultaneously in a straight line. Under the action of the staggered scrapers, the material can be better stirred. For example, when there are four scrapers 22 on the disc 21, the included angle of the scrapers 22 is 90°. Then, three discs 21 are grouped together, and adjacent discs 21 are staggered by 30°.

[0029] Based on the above technical solution, the cross-sectional shape of the scraper 22 is square, willow leaf-shaped, or wedge-shaped. The willow leaf shape is large in the middle and pointed at both ends, while the wedge shape is pointed at the front end and thick at the rear end. Both of these shapes are easy to insert into the material and have good guiding properties, while the pointed end of the willow leaf shape is easier to separate from the material.

[0030] Based on the above technical solution, the distance between adjacent dividing plates 14 gradually increases along the direction from the feed inlet 11 to the discharge outlet 12. As the reaction continues, the viscosity of the material increases closer to the discharge outlet 12, and the material is more likely to stick between the discs 21. Therefore, more and denser dividing plates 14 are needed to separate as much material as possible from the discs 21. The spacing between the dividing plates 14 is based on an even number of discs 21. For example, near the feed inlet 11, adjacent dividing plates 14 are spaced 4 discs 21 apart, and near the discharge outlet 12, adjacent dividing plates 14 are spaced 2 discs 21 apart.

[0031] Based on the above technical solution, the dividing plate 14 is fan-shaped, the arc edge of the dividing plate 14 is connected to the cylinder 1, any straight edge of the dividing plate 14 is connected to the bracket 15, and both ends of the bracket 15 are respectively connected to the cylinder 1. The bracket 15 strengthens the installation structure of the dividing plate 14 and prevents the dividing plate 14 from separating from the cylinder wall.

[0032] Numerous specific details are set forth in this specification. However, it will be understood that embodiments of this invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification. In the description of this specification, references to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of the different embodiments or examples.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model, and they should all be covered within the scope of the claims and specification of this utility model.

Claims

1. A polyester final polycondensation reactor, characterized in that, include: The cylinder has an inlet and an outlet at its lower ends, and an exhaust port is located above the outlet. A stirring shaft is provided inside the cylinder, and a number of discs are provided on the stirring shaft. A number of scrapers are evenly distributed on the outer circumferential surface of each disc. Several dividing plates are disposed above the interior of the cylinder and extend at intervals between the several disks.

2. The polyester final polycondensation reactor according to claim 1, characterized in that, The disk includes a central tube and an annular plate, and the central tube and the annular plate are connected by a plurality of evenly distributed spokes.

3. The polyester final polycondensation reactor according to claim 1, characterized in that, The number of scrapers on each of the discs is 4 to 12; The included angle between the scraper and the disc ranges from 15° to 75°, and the included angle between the disc and the scraper gradually decreases along the direction from the feed inlet to the discharge outlet.

4. The polyester final polycondensation reactor according to claim 1 or 3, characterized in that, The scrapers on adjacent disks are staggered.

5. The polyester final polycondensation reactor according to claim 4, characterized in that, The cross-sectional shape of the scraper is square, willow leaf-shaped, or wedge-shaped.

6. The polyester final polycondensation reactor according to claim 1, characterized in that, The distance between adjacent dividing plates gradually increases along the direction from the feed inlet to the discharge outlet.

7. The polyester final polycondensation reactor according to claim 1 or 6, characterized in that, The dividing plate is fan-shaped, with its arc edge connected to the cylinder body, and any straight edge of the dividing plate connected to the support. Both ends of the support are connected to the cylinder body.

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