A plug flow tower polymerization reaction system

Abstract

This invention discloses a plug flow tower polymerization reaction system, belonging to the field of chemical equipment technology. It includes a tower body with a plug flow working zone within it. A gas phase space is formed between the plug flow working zone and the top or bottom of the tower body. A gas phase channel penetrating the plug flow working zone is located at the central axis of the tower body. A falling film unit is provided in the plug flow working zone, and the falling film unit includes a falling film tray with a jacket. The jacket is used to introduce a heating medium, and the temperature of the falling film unit is controlled by regulating the heating medium. This invention achieves precise control of the polymerization reaction system by setting a falling film tray in the plug flow working zone, providing a jacket within the falling film tray, and introducing a heating medium into the jacket. The heating temperature is controlled by regulating the amount of heating medium.

Description

Technical Field

[0001] This invention belongs to the field of chemical equipment technology, specifically, it relates to a plug flow tower polymerization reaction system. Background Technology

[0002] Currently, the continuous polymerization production process of polyester polymers, such as PET, PBT, PTT, PBS, PBST, and PBAT, typically consists of esterification, pre-condensation, and final condensation reactions. The polymerization reactor is the main equipment responsible for the pre-condensation and final condensation reactions. Traditional polymerization reactors are typically vertical stirred-tank reactors, horizontal disc reactors, and horizontal cage reactors. Compared to vertical stirred-tank reactors, horizontal disc reactors and horizontal cage reactors significantly reduce backmixing of materials; however, their agitator structures are complex and difficult to manufacture. Furthermore, both horizontal disc reactors and horizontal cage reactors are dynamic equipment, resulting in high energy consumption.

[0003] Chinese patent application CN201110116240.4 discloses a downflow prepolymerization tower. This downflow prepolymerization reaction tower includes a cylindrical tower body, upper and lower end caps at the top and bottom of the tower body, and a plug flow working zone inside the tower body. This working zone is composed of several trays and baffles arranged alternately, ensuring that the downward-flowing material is constantly subjected to a repeated state of plugging and overflow. The downflow prepolymerization tower disclosed in this patent uses jacketed heating for temperature increase, which is a commonly used heating method for prepolymerization towers. However, if the prepolymerization tower is large, the heating effect is not significant and energy consumption is high. Furthermore, inconsistent temperatures may occur inside the prepolymerization tower, and precise temperature control for different reaction stages is not possible, affecting the reaction efficiency of the material inside the tower.

[0004] In addition, in the downflow prepolymer tower of this patent, the material overflows from the plug flow working area into the bottom end cap of the tower and cannot continue to maintain the plug flow, resulting in serious back mixing. Furthermore, the gas phase space at the bottom of the downflow prepolymer tower is small and the vacuum port is located at the bottom of the cylindrical tower body, which makes it easy for the material overflowing into the bottom end cap of the tower body to be entrained into the vacuum pipe by the polymerization by-product vapor, causing blockage.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a plug flow tower polymerization reaction system. The present invention aims to solve the problems of insignificant heating effect and high energy consumption of the prepolymer tower and the difficulty in controlling the internal temperature in the prior art.

[0007] To solve the above-mentioned technical problems, the basic concept of the technical solution adopted by the present invention is as follows:

[0008] A plug flow tower polymerization reaction system, comprising,

[0009] A tower-shaped cylindrical body is provided inside the tower-shaped cylindrical body, wherein a plug flow working zone is formed between the plug flow working zone and the top or bottom of the tower-shaped cylindrical body, and a gas phase space is provided at the central axis of the tower-shaped cylindrical body, which penetrates the plug flow working zone.

[0010] The plug flow working area is equipped with a falling film unit, which includes a falling film tray. The falling film tray has a jacket for introducing a heat medium, and the temperature of the falling film unit is controlled by regulating the heat medium.

[0011] Through the above design, a jacket is set inside the falling film tray, and a heat medium is introduced into the jacket. By controlling the heat medium flow rate of each falling film tray, the temperature of each tray can be controlled individually, so as to achieve differentiated control of the material temperature according to different reaction stages and improve the polymerization reaction rate of the material.

[0012] Furthermore, there is a gap between the gas phase channels of the falling film units in adjacent layers, and the width of the gap gradually increases towards the bottom of the tower-shaped cylinder.

[0013] Through the above design, the surface pressure of the first and second trays set in the tower body gradually decreases from the top to the bottom of the tower body, which facilitates the separation of polymerization reaction byproduct vapors.

[0014] Furthermore, the interlayer is provided with a first baffle and a second baffle.

[0015] The first baffle is arranged radially along the falling film tray, with one end connected to the outer peripheral edge of the falling film tray interlayer and the other end having a gap with the inner peripheral edge of the falling film tray interlayer.

[0016] The second baffle is arranged radially along the falling film tray, with one end connected to the inner peripheral edge of the falling film tray interlayer and the other end having a gap with the outer peripheral edge of the falling film tray interlayer;

[0017] Preferably, the falling film tray has a heat medium inlet and a heat medium outlet opposite each other on its radial outer peripheral sidewall;

[0018] Preferably, the first baffle and the second baffle on the side of the heat medium inlet and the heat medium outlet are alternately arranged in the interlayer; the first baffle and the second baffle on both sides of the heat medium inlet and the heat medium outlet are symmetrical.

[0019] With the above design, the heat medium enters the falling film tray and flows along the gap between the first baffle and the second baffle in the tray jacket, uniformly heating the falling film tray, thereby making the material heated and reacting uniformly.

[0020] Furthermore, the bottom of the tower body is provided with a back-mixing device, which causes the material flowing out of the push flow working area to be sequentially extracted from the discharge port.

[0021] The above design ensures that the material overflows from the plug flow working area in the tower and passes through the back-mixing device at the bottom of the tower, effectively preventing back-mixing of the material at the bottom of the tower and thus avoiding any impact on the efficiency of the polymerization reaction system.

[0022] Furthermore, the remixing device includes,

[0023] The outer chamber sleeve is a cylindrical structure with open ends and is located close to the inner wall of the tower cylinder. The bottom of the outer chamber sleeve is evenly provided with several slots, and the bottom end of the outer chamber sleeve is connected to the bottom wall of the tower cylinder.

[0024] The inner chamber sleeve is a cylindrical structure with open ends, which is disposed inside the outer chamber sleeve. The bottom end of the inner chamber sleeve is connected to the bottom wall of the tower-shaped cylinder.

[0025] Preferably, the outer chamber sleeve and the inner chamber sleeve are respectively coaxially arranged with the central axis of the tower body.

[0026] Through the above design, the outer chamber sleeve and the inner chamber sleeve have a simple structure, which can effectively prevent the material from being mixed back at the bottom of the tower body.

[0027] Furthermore, the outer sleeve includes,

[0028] A guide plate, wherein a plurality of slots are evenly provided around the bottom of the guide plate, and the bottom end of the guide plate is connected to the bottom wall of the tower-type cylinder.

[0029] A flow guide plate, the top of which is connected to the flow guide plate, guides the material into the space formed between the outer chamber sleeve and the tower body.

[0030] Through the above design, the guide plate introduces the material passing through the flat flow working area into the space formed between the outer chamber sleeve and the tower body, preventing the material from directly entering the outer chamber sleeve or the inner chamber sleeve, and effectively controlling the back mixing of the material.

[0031] Furthermore, the drainage plate is a conical structure that contracts inward toward the interior of the outer chamber sleeve;

[0032] Preferably, the drainage plate at least covers the opening between the outer chamber sleeve and the inner chamber sleeve;

[0033] Preferably, the top of the guide plate is higher than the top of the inner chamber sleeve.

[0034] With the above design, the flow guide plate has a simple structure, which allows the material to flow out of the flat flow working area and completely enter the space formed between the flow guide plate and the tower body. This prevents the material from passing through the space between the outer chamber sleeve and the inner chamber sleeve and into the interior of the inner chamber sleeve, and thus into the bottom of the tower body. It does not obstruct the material from overflowing into the interior of the inner chamber sleeve along the space between the flow guide plate and the inner chamber sleeve, and then being collected from the outlet.

[0035] Furthermore, the tower-shaped cylinder is equipped with a vortex applicator, which is a conical structure protruding from the center towards the bottom of the tower-shaped cylinder.

[0036] Through the above design, the swirling coating device allows the vapor of polymerization byproducts to enter the vacuum pipeline after defoaming, which can effectively prevent mist entrainment and avoid material from entering the vacuum pipeline and causing blockage.

[0037] Furthermore, the tower-shaped cylinder is also equipped with a vapor phase guide cylinder, which is a cylinder with one end open. The side wall of the vapor phase guide cylinder is provided with a vent, which is connected to a vacuum pipe; the vortex applicator is connected to the opening of the vapor phase guide cylinder.

[0038] Preferably, the vortex applicator is positioned above the plug flow working area of ​​the tower-shaped cylinder, and the gas phase outlet of the tower-shaped cylinder is positioned above the vortex applicator.

[0039] Alternatively, the gas phase guide tube is located below the horizontal flow working area and above the back mixing device, the gas phase outlet of the tower body is located below the tower body, and the gas phase outlet is connected to the vacuum pipe.

[0040] Through the above design, the swirling coating device allows the vapor of polymerization byproducts to enter the vacuum pipeline after being defoamed and de-foamed, which can effectively prevent mist entrainment and avoid material from entering the vacuum pipeline and causing blockage.

[0041] Furthermore, a semi-coil is provided circumferentially at the lower part of the tower-shaped cylinder;

[0042] Preferably, the outer wall of the tower cylinder equipped with a remixing device is provided with a semi-coil around its perimeter.

[0043] The above design allows the material to continue its polymerization reaction as it passes through the remixing device, further expelling the byproduct vapors, while the semi-tube jacket provides the necessary heat.

[0044] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art.

[0045] (1) The present invention sets up a falling film unit in the plug flow working area, and by setting up a jacket in the falling film unit and introducing a heat medium into the jacket, the temperature of the falling film tray is controlled, thereby achieving the purpose of differentially controlling the material temperature according to different reaction stages and improving the polymerization reaction rate of the material.

[0046] (2) The present invention provides baffles in the sandwich layer to guide the flow of heat medium and uniformly heat the tray, thereby achieving uniform heating of the material and improving the polymerization reaction rate of the material.

[0047] (3) The present invention provides a back-mixing device at the bottom of the tower body, so that after the material falls into the bottom of the tower body through the flat flow working area, the material back-mixing is effectively avoided, which affects the degree of material polymerization reaction.

[0048] (4) The present invention provides a swirling coating device in the tower body to remove the material entrained in the reaction byproduct vapor, effectively prevent mist entrainment, and avoid the problem of material entering the vacuum pipeline and causing blockage.

[0049] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0050] The accompanying drawings, as part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention, but do not constitute an undue limitation of the invention. Obviously, the drawings described below are merely some embodiments, and those skilled in the art can obtain other drawings based on these drawings without creative effort. In the drawings:

[0051] Figure 1 This is a schematic diagram of the structure of a first embodiment of a plug flow tower polymerization reaction system of the present invention;

[0052] Figure 2 This is a schematic diagram of the structure of a second embodiment of a plug flow tower polymerization reaction system according to the present invention;

[0053] Figure 3 This is the present invention. Figure 1 Enlarged view of point A in the middle;

[0054] Figure 4 This is a schematic diagram of the structure of the falling film tray of the present invention;

[0055] Figure 5 This is a schematic diagram of the structure of the falling film tray II of the present invention;

[0056] Figure 6 yes Figure 1 and Figure 2 Schematic diagram of the connection structure between the outer and middle chamber sleeves and the tower-type cylinder.

[0057] In the diagram: 1. Tower-type shell; 10. Plug flow working zone; 11. Falling film unit; 12. Falling film tray; 120. First tray; 121. First annular weir plate; 1210. First guide hole; 122. Second tray; 123. Second annular weir plate; 1230. Second guide hole; 124. Tray ring plate; 125. Heat medium inlet; 126. Heat medium outlet; 127. Jacket; 12 8. First baffle plate; 129. Second baffle plate; 13. Gas phase channel; 130. Gas phase outlet; 14. Back-mixing device; 15. Outer chamber sleeve; 151. Guide plate; 152. Drain plate; 153. Slot; 154. Fixing rib; 16. Inner chamber sleeve; 17. Swirl applicator; 18. Gas phase guide tube; 19. Half coil; 2. Inlet; 3. Outlet; 4. Conical umbrella plate.

[0058] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0059] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0060] In the description of this invention, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "inner", "outer", etc., 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 invention and simplifying the description, and 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. Therefore, they should not be construed as limiting this invention.

[0061] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0062] like Figures 1 to 6 As shown, the present invention provides a plug flow tower polymerization reaction system, comprising,

[0063] A tower-type cylindrical body 1 is provided inside the tower-type cylindrical body 1, and a plug flow working zone 10 is formed between the plug flow working zone 10 and the top or bottom of the tower-type cylindrical body 1. The tower-type cylindrical body 1 has a gas phase channel 13 that penetrates the plug flow working zone 10 at the central axis position.

[0064] The plug flow working area 10 is provided with a falling film unit 11, which includes a falling film tray 12. The falling film tray 12 is provided with a jacket 127, which is used to introduce a heat medium. The temperature of the falling film unit 11 is controlled by adjusting the heat medium.

[0065] The tower-shaped cylindrical body 1 of the present invention includes a cylindrical tower body, an upper end cap at the top of the cylindrical tower body, and a lower end cap at the bottom of the cylindrical tower body; as shown... Figure 1 and 2 As shown, the arrows indicate the direction of gas or material flow. Specifically, the upper part of the cylindrical tower body is provided with a feed inlet 2, and the lower part of the cylindrical tower body is provided with a discharge outlet 3. The discharge outlet 3 is located at the center of the lower end cap. The material enters the interior of the tower body 1 through the feed inlet 2 located at the upper part of the tower body 1 and falls into the falling film unit 11 of the plug flow working area 10. The falling film unit 11 of the present invention is composed of falling film trays 12. Each layer of falling film trays 12 is provided with a jacket 127. A heat medium can be introduced into the jacket 127 to heat the falling film trays 12. By controlling the flow rate of the heat medium, the temperature of each layer of falling film trays 12 can be controlled individually, thereby controlling the temperature of the material on the falling film trays 12. Differential control of the material temperature can be achieved according to different stages of the polymerization reaction, thereby improving the polymerization rate and degree of polymerization.

[0066] Furthermore, such as Figure 3 As shown, there is a gap between the gas phase channels 13 of two adjacent falling film units 11, and the width of the gap gradually increases towards the bottom of the tower body 1;

[0067] Preferably, the width of the slit is 0.5 to 5 cm.

[0068] Through the above design, the gap between the falling film units 11 serves as a conduit for the polymerization byproduct vapor to enter the gas phase channel 13. As the material flows horizontally through the falling film unit 11, the viscosity of the polymerization reactants gradually increases, thus gradually increasing the gap width from top to bottom. This facilitates the discharge of polymerization byproduct vapor without entraining too much material. The surface pressure of the falling film tray 12 located inside the tower body 1 gradually decreases from top to bottom, accelerating the volatilization of the byproduct vapor.

[0069] Furthermore, such as Figure 4 and 5 As shown, the interlayer 127 is provided with a first baffle 128 and a second baffle 129.

[0070] The first baffle plate 128 is arranged radially along the falling film tray 12, with one end connected to the outer peripheral edge of the interlayer 127 of the falling film tray 12, and the other end having a gap with the inner peripheral edge of the interlayer 127 of the falling film tray 12.

[0071] The second baffle plate 129 is arranged radially along the falling film tray 12, with one end connected to the inner peripheral edge of the falling film tray 12 and the other end having a gap with the outer peripheral edge of the falling film tray 12;

[0072] Preferably, the falling film tray 12 is provided with a heat medium inlet 125 and a heat medium outlet 126 opposite to each other on the radial outer peripheral sidewall;

[0073] Preferably, the first baffle 128 and the second baffle 129 on one side of the heat medium inlet 125 and the heat medium outlet 126 are alternately arranged in the interlayer 127; the first baffle 128 and the second baffle on both sides of the heat medium inlet 125 and the heat medium outlet 126 are symmetrical.

[0074] To ensure uniform heating of the falling film tray 12, the present invention provides a first baffle 128 and a second baffle 129 in the interlayer 127 of the falling film tray 12. The first baffle 128 and the second baffle 129 can be flat or corrugated. When the heat medium flows through the interlayer 127, it passes through the corrugated baffles, creating turbulence, and then flows through the gap between the first baffle 128, the second baffle 129, and the inner wall of the interlayer 127, thus heating the entire falling film tray 12. Preferably, multiple first baffles 128 and second baffles 129 can be provided, but not too many, as this would affect the flow rate of the heat medium and the heating rate. Preferably, the heat medium inlet 125 and the heat medium outlet 126 are located on the outer peripheral sidewall of the falling film tray 12, and the sidewall of the tower body 1 is provided with a connecting pipe inlet and a connecting pipe outlet corresponding to the heat medium inlet 125 and the heat medium outlet 126, and the heat medium is fed into the jacket 127 from the outside through the connecting pipe. Figure 3 and 4 As shown, the tower body 1 is provided with through holes corresponding to the heat medium inlet 125 and the heat medium outlet 126, and the through holes are connected to the heat medium pipe. The heat medium pipe connects the heat medium inlet 125 and the heat medium outlet 126. Elastic elements are provided between the heat medium inlet 125 and the heat medium outlet 126 on the side wall of the jacket 127 of the falling film tray 12 and the through holes and the heat medium pipe of the tower body 1, so that the jacket 127 of the falling film tray 12, the tower body 1 and the heat medium pipe are leak-free flexible connections, which are easy to disassemble and assemble. The elastic elements also have the function of eliminating vibration and extending the service life of the tower body 1.

[0075] Furthermore, such as Figure 1 and 2As shown in Figures 4 and 5, the falling film tray 12 includes,

[0076] The first tower plate is 120, as follows Figure 4 As shown, the first tray 120 is provided with a sandwich 127. The outer edge of the first tray 120 is connected to the side wall of the tower body 1. The inner edge of the first tray 120 is connected to the first annular weir plate 121 coaxial with the gas phase channel 13. There is an annular gap between the first annular weir plate 121 and the gas phase channel 13.

[0077] Second tower plate 122, as Figure 5 As shown, the second tray 122 is provided with a sandwich 127, and the outer edge of the second tray 122 is connected to a second annular weir plate 123 coaxial with the gas phase channel 13. There is an annular gap between the second annular weir plate 121 and the side wall of the tower body 1.

[0078] The tray ring plate 124 is connected at one end to the inner edge of the second tray 122 and at the other end extends toward the top of the tower body 1. The tray ring plate 124 forms a gas phase channel 13.

[0079] Preferred, such as Figure 3 As shown, the first tray 120 is provided with a plurality of first guide holes 1210 and second guide holes 1230 evenly on the inner side of the first annular weir plate 121 and the second tray 122 is provided with a plurality of first guide holes 1210 and second guide holes 1230 on the inner side of the second annular weir plate 123.

[0080] Specifically, both the first tray 120 and the second tray 122 have a heat medium inlet 125 and a heat medium outlet 126 on their radially outer peripheral sidewalls. Preferably, the heat medium inlet 125 of the first tray 120 corresponds to the heat medium inlet 125 of the second tray 122, and the heat medium outlet 126 of the first tray 120 corresponds to the heat medium outlet 126 of the second tray 122.

[0081] The material flows into the falling film unit 11, first into the first tray 120, and then flows horizontally through the first annular weir plate 121 and the first guide hole 1210 into the second tray 122. It then flows from the second annular weir plate 123 of the second tray 122 into the next falling film unit 11 through the second guide hole 1230, and so on.

[0082] The first annular weir plate 121 extends to the second tray 122, and the second annular weir plate 123 extends to the first tray 120 of the next falling film unit 11. The first annular weir plate 121 and the second annular weir plate 123 serve as flow guides. The tray structure of the present invention is relatively simple. The first flow guide hole 1210 and the second flow guide hole 1230 are respectively arranged inside the first annular weir plate 121 and the second annular weir plate 123. This can ensure the horizontal flow distance of the material in the falling film unit 11, and also make the root of the first annular weir plate 121 or the second annular weir plate 123 free of dead zones, making it closer to a horizontal flow, and flowing to the next tray.

[0083] Specifically, there is a gap between adjacent tower tray ring plates 124, and the width of the gap gradually increases towards the bottom of the tower body 1.

[0084] Specifically, the first baffle plate 128 is radially arranged along the first tray 120 and the second tray 122, with one end connected to the outer peripheral edge of the interlayer 127 between the first tray 120 and the second tray 122, and the other end having a gap with the inner peripheral edge of the interlayer 127 between the first tray 120 and the second tray 122.

[0085] The second baffle plate 129 is arranged radially along the first tray 120 and the second tray 122, with one end connected to the inner peripheral edge of the interlayer 127 between the first tray 120 and the second tray 122, and the other end having a gap with the outer peripheral edge of the interlayer 127 between the first tray 120 and the second tray 122.

[0086] Preferably, the first tray 120 and the second tray 122 are respectively provided with a heat medium inlet 125 and a heat medium outlet 126 on their radial outer peripheral sidewalls.

[0087] Preferably, the first baffle 128 and the second baffle 129 on one side of the heat medium inlet 125 and the heat medium outlet 126 are alternately arranged in the interlayer 127 of the first tray and the second tray 122; the first baffle 128 and the second baffle 129 on both sides of the heat medium inlet 125 and the heat medium outlet 126 are symmetrical.

[0088] Preferably, the second baffles 129 are provided on both sides of the heat medium inlet 125 and the second baffles 129 are provided on both sides of the heat medium outlet 126. The heat medium enters the interlayer 127 and flows in along the gaps between the second baffles 129 and the outer peripheral edge of the first tray 120 and the gaps between the second baffles 129 and the outer peripheral edge of the second tray 122, flows through the gap between the first baffles 128 and the second baffles 129, and then flows along the gap between the first baffles 128 and the inner peripheral edge of the first tray 120 and the second tray 122 into the next gap between the first baffles 128 and the second baffles 129, gradually heating the first tray 120 and the second tray 122. Finally, the heat medium flows out from the heat medium outlet 126 between the two second baffles 129. The first baffle plate 128 and the second baffle plate 129 are arranged in the same form in the first tray 120 and the second tray 122. Those skilled in the art can also make adjustments according to actual conditions to achieve the purpose of uniformly heating the first tray 120 and the second tray 122.

[0089] Furthermore, the bottom of the tower body 1 is provided with a back-mixing device 14, which causes the material flowing out of the push flow working area 10 to be sequentially extracted from the discharge port 3.

[0090] After multiple falling film processes, the material falls to the bottom of the tower body 1. Generally, the lower end cap of the tower body 1 is an arc-shaped structure. After the material enters the lower end cap, it cannot continue to maintain the horizontal flow motion, resulting in severe backmixing. The backmixing device 14 significantly reduces the degree of backmixing of the material at the bottom of the tower body 1 in the horizontal flow tower polymerization reaction system, thereby improving the polymerization reaction efficiency.

[0091] Furthermore, the remixing device 14 includes,

[0092] The outer chamber sleeve 15 is a cylindrical structure with open ends and is located close to the inner wall of the tower-type cylinder 1. The bottom of the outer chamber sleeve 15 is evenly provided with several slots, and the bottom end of the outer chamber sleeve 15 is connected to the bottom wall of the tower-type cylinder.

[0093] Inner chamber sleeve 16, the inner chamber sleeve 16 is a cylindrical structure with open ends, and is disposed inside the outer chamber sleeve 15. The bottom end of the inner chamber sleeve 16 is connected to the bottom wall of the tower-type cylinder 1.

[0094] Preferably, the outer chamber sleeve 15 and the inner chamber sleeve 16 are respectively coaxially arranged with the central axis of the tower body 1.

[0095] The outer chamber sleeve 15 and the inner chamber sleeve 16 divide the lower part of the tower-shaped cylinder 1 into an outer chamber formed between the outer chamber sleeve 15 and the inner wall of the tower-shaped cylinder 1, a middle chamber formed between the outer chamber sleeve 15 and the inner chamber sleeve 16, and an inner chamber formed inside the inner chamber sleeve 16. The radial widths of the outer chamber and the middle chamber can be adjusted according to actual conditions. The back-mixing device 14 has a simple structure, is easy to install, and has a significant back-mixing effect. Specifically, the outer chamber sleeve 15 is located at the upper part of the lower end cap.

[0096] More specifically, such as Figure 6 As shown, the slot 153 can be a long slot-shaped hole. The bottom end of the outer chamber sleeve 15 is welded and fixed to the bottom wall of the tower-shaped cylinder 1. The slot 153 allows the material entering the outer chamber to flow into the middle chamber through the slot 153. The number and size of the slots 153 are not limited here, as long as the material can flow smoothly from the outer chamber into the middle chamber and the outer chamber sleeve 15 is stable in the tower-shaped cylinder 1. To increase the seismic resistance of the outer chamber sleeve 15, several fixed parts are also provided on the upper part of the outer chamber sleeve 15 in actual use. The fixing rib 154 can be a rib or a rib plate. One end of the fixing rib 154 is connected to the outer wall of the outer chamber sleeve 15, and the other end is connected to the inner wall of the tower-shaped cylinder 1. Multiple fixing ribs 154 can be evenly arranged radially along the outer chamber sleeve 15. Preferably, 4 to 12 fixing ribs are evenly arranged radially along the outer chamber sleeve 15, or 3 are evenly arranged circumferentially along the outer chamber sleeve 15. The fixing ribs 154 prevent the upper part of the outer chamber sleeve 15 from shaking, increasing the stability of the outer chamber sleeve 15. The fixing ribs 154 are welded and fixed to the outer chamber sleeve 15 and the side wall of the tower-shaped cylinder 1. Under the influence of gravity, the material flows through the plug flow working zone 10 and enters the outer chamber between the lower part of the tower body 1 and the outer chamber sleeve 15. It then flows through the gap between the outer chamber sleeve 15 and the tower body 1 into the middle chamber, overflows from the middle chamber into the inner chamber, and is finally extracted from the bottom of the inner chamber. By utilizing the material's certain viscosity, the material entering the outer chamber is stacked, and the material at the top is squeezed into the middle chamber first and overflows from the middle chamber into the inner chamber. This can effectively prevent back mixing of the material and improve the polymerization reaction efficiency.

[0097] Furthermore, the outer sleeve 15 includes,

[0098] The guide plate 151 has a plurality of slots 153 evenly provided around its bottom circumference, and the bottom end of the guide plate 151 is at a certain distance from the bottom wall of the tower cylinder 1.

[0099] The guide plate 152 is connected to the top of the guide plate 151. The guide plate 152 introduces the material into the space formed between the outer chamber sleeve 15 and the tower body 1.

[0100] More specifically, the upper end of the slot 153 of the guide plate 151 can be flush with the upper end of the lower end cap, which facilitates the flow of material into the middle chamber under the action of the lower end cap and the slot 153. It also facilitates the accumulation of material, gradually squeezing the material that flows out first into the middle chamber, and then overflowing into the inner chamber and being collected in sequence, effectively avoiding back mixing. The top end of the guide plate 151 is welded and fixed to the bottom end of the guide plate 152.

[0101] More specifically, the fixing ribs 154 can be respectively disposed on the guide plate 151 and the diversion plate 152. The fixing ribs 154 disposed on the guide plate 151 and the diversion plate 152 can be disposed in the same position or can be disposed crosswise.

[0102] The number of fixing ribs 154 can be adjusted according to the actual size of the tower body 1.

[0103] Furthermore, the drainage plate 152 is a conical structure that contracts inward toward the interior of the outer chamber sleeve 15;

[0104] Preferably, the drainage plate 152 at least covers the opening between the outer chamber sleeve 15 and the inner chamber sleeve 16;

[0105] Preferably, the top of the guide plate 151 is higher than the top of the inner chamber sleeve 16.

[0106] The guide plate 152 of the present invention has a simple structure and can effectively prevent materials from entering the middle chamber or inner chamber. The top of the guide plate 151 is higher than the top of the inner chamber sleeve 16. The guide plate 152 will not obstruct or hinder the overflow of materials in the middle chamber due to its inclination towards the inner chamber. The overflowing materials entering the inner chamber are gradually extracted from the outlet 3.

[0107] Furthermore, such as Figure 1 and 2 As shown, the tower-shaped cylinder 1 is equipped with a vortex applicator 17, which is a conical structure that protrudes from the center toward the bottom of the tower-shaped cylinder 1.

[0108] The cyclone applicator 17 of the present invention adopts a conical structure, which can increase the surface area of ​​the cyclone applicator 17, increase the contact area between the polymerization reaction by-product vapor and the cyclone applicator 17, improve the gas-liquid separation efficiency, and also facilitate the application of materials into the gas phase guide tube 18.

[0109] Furthermore, such as Figure 1 As shown, the tower-shaped cylinder 1 is also provided with a gas phase guide cylinder 18. The gas phase guide cylinder 18 is a cylinder with one end open. The side wall of the gas phase guide cylinder 18 is provided with a vent, and the vent is connected to a vacuum pipe. The vortex applicator 17 is connected to the opening of the gas phase guide cylinder 18.

[0110] Preferred, such as Figure 2 As shown, the vortex applicator 17 is positioned above the plug flow working zone 10 of the tower body 1, and the gas phase outlet 130 of the tower body 1 is positioned above the vortex applicator 17.

[0111] Or, such as Figure 1 As shown, the gas phase guide tube 18 is located below the horizontal flow working area 10 and above the back mixing device 14. The gas phase outlet 130 of the tower body 1 is located below the tower body 1, and the gas phase outlet 130 is connected to the vacuum pipe.

[0112] The present invention employs a gas phase guide tube 18, which on the one hand provides a large flow space for polymerization by-product vapor, and on the other hand facilitates connection to a vacuum pipeline to extract the polymerization reaction by-product vapor of the separated materials from the tower body 1 in a targeted manner.

[0113] Furthermore, a semi-coil 19 is provided circumferentially at the lower part of the tower-shaped cylinder 1;

[0114] Preferably, the outer wall of the tower cylinder 1 equipped with the remixing device 14 is provided with a semi-coil 19.

[0115] The present invention only sets a half-pipe jacket at the lower part of the tower body 1, which saves materials and costs. Preferably, the half-pipe jacket is set at the position where the back mixing device 14 is set, which helps to prevent back mixing. The half-pipe jacket can be set according to the actual situation.

[0116] Example 1

[0117] like Figure 1 As shown in this embodiment, a plug flow tower polymerization system employs the aforementioned polymerization system. The bottom sidewall of the tower body 1 is provided with a gas phase outlet 130. Preferably, the gas phase outlet 130 is located below the plug flow working zone 10 and above the backmixing device 14. A conical umbrella plate 4 is provided between the plug flow working zone 10 and the top of the tower body 1. The feed inlet 2 is located above the conical umbrella plate 4. The material enters the tower body 1 through the feed inlet 2 and flows down along the upper surface of the conical umbrella plate 4 in a falling film manner, falling into the first tray 120 of the falling film unit 11. After flowing horizontally on the first tray 120, the material enters the second tray 122 and sequentially flows through the other falling film units 11 of the plug flow working zone 10, flowing towards the bottom of the tower body 1.

[0118] In this embodiment, the gap width between the gas phase channels 13 of two adjacent falling film units 11 is set to be between 0.5 and 2 cm. Specifically, the gap width between two adjacent tray ring plates 124 is set to be between 0.5 and 2 cm.

[0119] In this embodiment, a swirling coating device is provided inside the tower-shaped cylinder 1. The swirling coating device includes...

[0120] Swirl applicator 17, wherein the swirl applicator 17 is a conical structure protruding from the center toward the bottom of the tower-shaped cylinder 1;

[0121] A vapor phase guide tube 18 is a cylindrical structure with one end open. The side wall of the vapor phase guide tube 18 is provided with a vent, which is connected to a vacuum pipe. The opening of the vapor phase guide tube 18 is connected to the vortex applicator 17.

[0122] Preferably, the swirling coating device is located below the flat flow working area 10 (or gas phase channel 13) and above the back mixing device 14.

[0123] Preferably, the other end of the gas phase guide tube 18 is a conical or arc-shaped structure that protrudes outward.

[0124] The vent is connected to a vacuum pipe, which is located in the gas phase outlet 130. The polymerization byproduct vapor is deflected and defoamed by the cyclone demister and then enters the vacuum gas phase pipe through the gas phase outlet 130 to be extracted from the polymerization reaction system.

[0125] The present invention employs a gas phase guide tube 18, which on the one hand provides a large flow space for polymerization by-product vapor, and on the other hand facilitates connection to a vacuum pipeline to extract the polymerization reaction by-product vapor of the separated materials from the tower body 1 in a targeted manner.

[0126] Specifically, the opening diameter of the guide plate 152 is smaller than the diameter of the cyclone applicator 17, so that the cyclone applicator 17 performs gas-liquid separation on the polymerization by-product vapor in the inner chamber. The separated material flows back to the bottom of the tower body 1 along the cyclone applicator 17. Even if it flows back to the outer chamber, only a small amount of material is separated, so no new backmixing will occur.

[0127] Preferably, the falling film unit 11 has 20 layers.

[0128] Implementation effect

[0129] The succinic acid-terephthalic acid-butanediol copolyester with an esterification rate of 98% is continuously fed into the above-mentioned plug flow tower polymerization reactor, wherein the molar ratio of succinic acid to terephthalic acid structural units in the succinic acid-terephthalic acid-butanediol copolyester is 1:1; the temperature of the first tray 120 and the second tray 122 of the first to fifth tray units in the plug flow tower polymerization system of the present invention is 240°C, the temperature of the first tray 120 and the second tray 122 of the sixth to tenth tray units is 250°C, and the temperature of the first tray 120 and the second tray 122 of the eleventh to twentieth tray units is 260°C; the pressure inside the tower body 1 is 5 kPa; the intrinsic viscosity of the obtained succinic acid-terephthalic acid-butanediol ester prepolymer is 0.60 dL / g, and the turbidity of the polymerization by-product fraction is 75 NTU; the temperature of the tray units is set in zones to improve accuracy and save energy.

[0130] Example 2

[0131] like Figure 2 As shown in the figure, the plug flow tower polymerization system described in this embodiment adopts the above-mentioned polymerization system. The top of the tower body 1 is provided with a gas phase outlet 130, specifically, the gas phase outlet 130 is located in the upper end cap. In this embodiment, the conical umbrella plate 4 is not provided. The first falling film tray 12 of the plug flow operation is the second tray 122 mentioned above. The feed inlet 2 is located above the second tray 122. The outlet of the feed inlet 2 is close to the inner side of the tray ring plate 124, ensuring that the material falls to the next layer of falling film tray 12 after the plug flow in the second tray 122, that is, the first tray 120 of the next layer. The difference between this embodiment and embodiment one is that the conical umbrella plate 4 is not provided. Therefore, the first falling film tray 12 of the plug flow working area 10 is set as the second tray 122 in the falling film unit 11, which facilitates the plug flow during feeding. Then, it flows through the other falling film units 11 of the plug flow working area 10 in sequence to the bottom of the tower body 1.

[0132] In this embodiment, the gap width between the gas phase channels 13 of two adjacent falling film units 11 is set to be between 2 and 5 cm. Specifically, the gap width between two adjacent tray ring plates 124 is set to be between 2 and 5 cm.

[0133] In this embodiment, the tower-shaped cylinder 1 is provided with a vortex applicator 17, which is a conical structure that protrudes from the center toward the bottom of the tower-shaped cylinder 1.

[0134] The cyclone applicator 17 of the present invention adopts a conical structure, which can increase the surface area of ​​the cyclone applicator 17, increase the contact area between the polymerization reaction by-product vapor and the cyclone applicator 17, and improve the gas-liquid separation efficiency. After the polymerization by-product vapor is deflected and defoamed by the cyclone demister, it enters the vacuum gas phase pipeline through the gas phase outlet 130 to be extracted from the reaction system.

[0135] Preferably, the vortex applicator 17 is positioned above the horizontal flow working area 10 (or above the gas phase channel 13); more preferably, the vortex applicator 17 is positioned below the upper end cap, such that the gas phase outlet 130 is located above the vortex applicator 17. In this case, the vortex applicator 17 can be directly connected to the inner wall of the tower-type cylinder 1, eliminating the need for the gas phase guide tube 18. This makes the structure of the vortex applicator 17 simpler and easier to install.

[0136] Preferably, the falling film unit 11 has 8 layers.

[0137] Implementation effect

[0138] The ethylene glycol terephthalate ester with an esterification rate of 97% is continuously fed into the aforementioned plug flow tower polymerization reactor. The temperature of the first second tray 122 in the plug flow tower polymerization system is 275°C. Subsequently, the temperatures of the first tray 120 and second tray 122 in the first and second tray units are 275°C, the temperatures of the first tray 120 and second tray 122 in the third and fourth tray units are 280°C, and the temperatures of the first tray 120 and second tray 122 in the fifth to eighth tray units are 285°C. The pressure inside the tower body 1 is 3 kPa. The intrinsic viscosity of the obtained ethylene glycol terephthalate prepolymer is 0.30 dL / g, and the turbidity of the polymerization by-product fraction is 90 NTU. The zoned setting of the tray unit temperatures improves accuracy while saving energy.

[0139] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A plug flow tower polymerization system, comprising a tower body, wherein a plug flow working zone is disposed within the tower body, and a gas phase space is formed between the plug flow working zone and the top or bottom of the tower body, wherein a gas phase channel penetrating the plug flow working zone is located at the central axis of the tower body, characterized in that: The plug flow working area is provided with a falling film unit, which includes a falling film tray. The falling film tray includes: a first tray, the outer edge of which is connected to the side wall of the tower body, and the inner edge of which is connected to a first annular weir plate coaxial with the gas phase channel. There is an annular gap between the first annular weir plate and the gas phase channel. The second tray has an outer edge connected to a second annular weir plate coaxial with the gas phase channel, and there is an annular gap between the second annular weir plate and the side wall of the tower body. The tray ring plate has one end connected to the inner edge of the second tray and the other end extending towards the top of the tower body to form a gas phase channel. There is a gap between adjacent tray ring plates, which forms a gap between the gas phase channels of two adjacent falling film units. The width of the gap gradually increases towards the bottom of the tower body. The first tray and the second tray are uniformly provided with a plurality of first guide holes and second guide holes near the inner side of the first annular weir plate; The falling film tray is provided with a jacket, which is used to introduce a heat medium, and the temperature of the falling film unit is controlled by adjusting the heat medium. The interlayer is provided with a first baffle and a second baffle. The first baffle is arranged radially along the falling film tray, with one end connected to the outer peripheral edge of the falling film tray interlayer and the other end having a gap with the inner peripheral edge of the falling film tray interlayer. The second baffle is arranged radially along the falling film tray, with one end connected to the inner peripheral edge of the falling film tray and the other end having a gap with the outer peripheral edge of the falling film tray; The falling film tray has a heat medium inlet and a heat medium outlet arranged radially opposite each other on its outer peripheral sidewall, and the heat medium inlet and the heat medium outlet are located at opposite ends of the same diameter of the falling film tray. Within the interlayer on both sides of the diameter where the heat medium inlet and outlet are located, a first baffle plate and a second baffle plate are alternately arranged. The alternately arranged first baffle plate and second baffle plate are symmetrically arranged with the diameter as the axis of symmetry. The tower-shaped cylinder is provided with through holes corresponding to the heat medium inlet and the heat medium outlet. The through holes are connected to heat medium pipes, and the heat medium pipes are connected to the heat medium inlet and the heat medium outlet.

2. The plug flow tower polymerization reaction system according to claim 1, characterized in that: The bottom of the tower body is equipped with a back-mixing device, which causes the material flowing out of the push flow working area to be sequentially extracted from the discharge port.

3. The plug flow tower polymerization reaction system according to claim 2, characterized in that: The back-mixing device includes: an outer chamber sleeve, which is a cylindrical structure with open ends and is located close to the inner wall of the tower cylinder. The bottom of the outer chamber sleeve is evenly provided with several slots, and the bottom end of the outer chamber sleeve is connected to the bottom wall of the tower cylinder. The inner chamber sleeve is a cylindrical structure with open ends, which is disposed inside the outer chamber sleeve. The bottom end of the inner chamber sleeve is connected to the bottom wall of the tower-shaped cylinder.

4. The plug flow tower polymerization reaction system according to claim 3, characterized in that: The outer chamber sleeve and the inner chamber sleeve are respectively coaxially arranged with the central axis of the tower body.

5. A plug flow tower polymerization reaction system according to claim 3, characterized in that: The outer chamber sleeve includes: a guide plate, the bottom of which is evenly provided with a plurality of slots, and the bottom end of the guide plate is connected to the bottom wall of the tower-type cylinder; A flow guide plate, the top of which is connected to the flow guide plate, guides the material into the space formed between the outer chamber sleeve and the tower body.

6. The plug flow tower polymerization reaction system according to claim 5, characterized in that: The drainage plate is a conical structure that contracts inward toward the interior of the outer chamber sleeve.

7. A plug flow tower polymerization reaction system according to claim 6, characterized in that: The top diameter of the conical structure of the diversion plate is smaller than the bottom diameter. The bottom end of the diversion plate is connected to the guide plate. The bottom diameter is larger than the diameter of the inner chamber sleeve, and the top diameter is smaller than the diameter of the inner chamber sleeve.

8. A plug flow tower polymerization reaction system according to claim 6, characterized in that: The top of the guide plate is higher than the top of the inner chamber sleeve.

9. A plug flow tower polymerization reaction system according to claim 1, characterized in that: The tower-shaped cylinder is equipped with a vortex applicator, which is a conical structure that protrudes from the center to the bottom of the tower-shaped cylinder.

10. A plug flow tower polymerization reaction system according to claim 9, characterized in that: The tower-shaped cylinder is also equipped with a gas phase guide cylinder, which is a cylinder with one end open. The side wall of the gas phase guide cylinder is provided with a vent, which is connected to a vacuum pipe. The vortex applicator is connected to the opening of the gas phase guide cylinder.

11. A plug flow tower polymerization reaction system according to claim 10, characterized in that: The vortex applicator is positioned above the horizontal flow working area of ​​the tower body, and the gas phase outlet of the tower body is positioned above the vortex applicator. Alternatively, the gas phase guide tube is positioned below the horizontal flow working area and above the back mixing device, and the gas phase outlet of the tower body is positioned below the tower body. The gas phase outlet is connected to the vacuum pipe.

12. The plug flow tower polymerization reaction system according to claim 1, characterized in that: The lower part of the tower-shaped cylinder is provided with a semi-coil.

13. A plug flow tower polymerization reaction system according to claim 12, characterized in that: The outer wall of the tower-shaped cylinder corresponding to the remixing device is provided with a semi-coil around its perimeter.

Images