Parallel type vertical melt polycondensation reaction device

Abstract

The utility model provides a parallel type vertical melt polycondensation reaction device, and belongs to the technical field of efficient and energy-saving type special equipment for chemical engineering. Comprising a feeding main pipe, a first communicating piece, a feeding branch pipe, a feeding melt gear pump, polycondensation reactors, a discharging melt gear pump, a discharging branch pipe, a second communicating piece and a discharging main pipe, different on-off states of a feeding valve and a discharging valve are controlled, and parallel connection of the polycondensation reactors is achieved. According to the parallel type vertical melt polycondensation reactor device, the polycondensation reactors can be switched on the premise that normal production is not affected, so that production interruption caused by periodic reactor cleaning operation is avoided, the continuous and stable operation of the polymerization-tackifying-spinning process is guaranteed, the production cost is reduced, and the production efficiency is improved.

Description

Technical Field

[0001] The present application relates to a parallel vertical melt polycondensation reaction device, which belongs to the technical field of high-efficiency and energy-saving chemical special equipment. Background Art

[0002] Vertical falling-film melt polycondensation reactors are a new type of reactor for producing high-viscosity polyester products. They offer advantages such as simple structure, energy conservation, environmental protection, and high reaction efficiency. They have been widely used in the industrial production of high-molecular-weight polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polyamide (PA), and polycarbonate (PC). However, the reaction temperatures of vertical melt polycondensation reactors are generally relatively high. While this highly efficient polycondensation reaction can also trigger a series of side reactions, resulting in product yellowing and the formation of branched cross-linked products, coke, and carbonized byproducts, seriously impacting product quality. In actual production, regular cleaning of the polycondensation reactor is a common method to address these issues. This cleaning removes degradation products, branched cross-linked products, coke, and carbonized products from the reactor interior, optimizing the reactor's condition for the next use and improving the quality of the polycondensation product.

[0003] For the melt-spinning device in polyester industrial yarn, the polymerization workshop, viscosity-increasing workshop and spinning workshop are directly connected by pipelines. When the condensation reactor in the viscosity-increasing workshop is undergoing kettle washing, it will affect the normal production of the front polymerization workshop and the back spinning workshop, causing output fluctuations. In severe cases, it will cause the stability of product quality to deteriorate, the product quality to decline, and ultimately affect the overall benefits of the enterprise. Utility Model Content

[0004] In view of this, the present application provides a parallel vertical melt polycondensation reaction device, which not only realizes the parallel connection of multiple polycondensation reactors, but also enables the entire production process to carry out kettle washing operations without stopping the machine. While cleaning the polycondensation reactor, it ensures the continuous and stable progress of "polymerization-viscosity increase-spinning" in the polyester industrial yarn melt direct spinning production line.

[0005] Specifically, this application is implemented through the following solutions:

[0006] A parallel vertical melt polycondensation reaction device includes a feed main pipe, a first connecting piece, a feed branch pipe, a feed melt gear pump, a polycondensation reactor, a discharge melt gear pump, a discharge branch pipe, a second connecting piece, and a discharge main pipe.

[0007] There are at least two feed branch pipes, and the number of feed melt gear pumps, polycondensation reactors, and discharge melt gear pumps are all arranged corresponding to the number of feed branch pipes;

[0008] The feed main pipe is connected to the feed branch pipe via a first connecting piece, and a feed valve is provided on the feed branch pipe;

[0009] The feed branch pipe is connected to the feed pipe via a feed melt gear pump, and the feed pipe is communicated with the polycondensation reactor;

[0010] One end of the discharge pipe is connected to the polycondensation reactor, and the other end is connected to the discharge branch pipe via a discharge melt gear pump;

[0011] The discharge branch pipe is provided with a discharge valve;

[0012] Each discharge branch pipe is connected to the discharge main pipe through a second connecting piece;

[0013] Control the different on and off of the feed valve and discharge valve to realize the parallel connection of each polycondensation reactor.

[0014] When the polycondensation reactor in the above working state is switched to the polycondensation reactor to be worked, first, the opening of the feed valve corresponding to the polycondensation reactor in the working state is reduced, the feed speed is reduced, and at the same time, the feed valve and feed melt gear pump corresponding to the polycondensation reactor to be worked are opened. When the feed of the polycondensation reactor to be worked reaches the preset liquid level, the material at the bottom of the polycondensation reactor to be worked is discharged until the material quality is stable; finally, the feed valve corresponding to the polycondensation reactor in the working state is closed, and the feed valve and feed melt gear pump corresponding to the polycondensation reactor to be worked are increased to the set value to complete the switching. The polycondensation reactor in the original working state that has completed the switching is converted to an idle state or enters a cleaning stage, and the original polycondensation reactor to be worked is converted to a working state.

[0015] In the above-mentioned parallel vertical melt polycondensation reaction device, the feed main pipe, the first connecting piece, the feed branch pipe and the feed melt gear pump constitute the feed zone, the parallel polycondensation reactor constitutes the reaction zone, and the discharge melt gear pump, the discharge branch pipe, the second connecting piece and the discharge main pipe constitute the discharge zone. When this device is used to replace the traditional single-reactor production system, the feed main pipe inputs a low-viscosity melt and the discharge main pipe outputs a high-viscosity melt. It can not only realize the simultaneous production and cleaning of polyester melt in the vertical melt polycondensation reactor, but also control the melt polycondensation reaction process. By adjusting the different residence times of the melt in the reaction zone, the different molecular weights and viscosities of the polyester melt can be improved, and the same equipment can be used to diversify the products processed. It can also effectively solve the current problem of production interruption during reactor cleaning, thereby ensuring continuous, stable and efficient production from polymerization to spinning, which is conducive to reducing costs and energy waste caused by downtime and excessive waste.

[0016] Furthermore, as a preference:

[0017] The discharge branch pipe is provided with a waste discharge pipe, and the waste discharge pipe is provided with a waste discharge valve for discharging waste materials in the polycondensation reactor.

[0018] The polycondensation reactor is a vertical falling film melt polycondensation reactor with the feed port at the top and the discharge port at the bottom. The falling film element in the polycondensation reactor can be adjusted to meet the production requirements of different polyester materials and different viscosity increases.

[0019] The melt gear pump is a gear pump capable of controlling the flow of polyester melt, and may include straight gear type, helical gear type, herringbone gear type, and the like.

[0020] In the above scheme,

[0021] The first connecting piece and the second connecting piece are pipes for regulating the flow direction of the polyester melt, which can change and control the low-viscosity polyester melt to flow to different polycondensation reactors and the high-viscosity polyester melt to flow out of different polycondensation reactors. Two structures can be used:

[0022] Structure 1, all are three-way pipe fittings. At this time: there are two feed branches, and the corresponding feed valves, feed melt gear pumps, polycondensation reactors, discharge melt gear pumps, discharge branches, and discharge valves are also provided. The two polycondensation reactors are set in parallel.

[0023] Structure 2 uses five-way pipe fittings. In this case, there are four feed branches, along with four corresponding feed valves, feed melt gear pumps, polycondensation reactors, discharge melt gear pumps, discharge branches, and discharge valves. The four polycondensation reactors are arranged in parallel. In this case, the four polycondensation reactors are arranged in a ring around the feed main pipe.

[0024] For the reaction devices with different structures described above, further diversion can be performed on the feed branch pipe, that is, at least one diversion tee is provided on the feed branch pipe, one end of the diversion tee is connected to the feed branch pipe, and the other two ends are each connected to a melt reactor, forming a parallel structure including multiple polycondensation reactors. If the first connecting piece and the second connecting piece are both tees, the polycondensation reactors can be expanded to at least three or more polycondensation reactors in parallel; if the first connecting piece and the second connecting piece are both five-way pipes, the polycondensation reactors can be expanded to at least five or more polycondensation reactors in parallel.

[0025] The parallel vertical melt polycondensation reactor device in the present application is allowed to include two or more polycondensation reactors in parallel. In the case of two polycondensation reactors, a linear arrangement can be adopted; when the number of parallel polycondensation reactors is greater than three (including three), the parallel forms of the polycondensation reactors are allowed to be linear arrangement and annular arrangement, among which the annular arrangement allows for arrangements such as circular arrangement and rectangular arrangement.

[0026] The parallel vertical melt polycondensation reactor device in this application can switch the polycondensation reactor without affecting normal production, thereby avoiding production interruptions caused by periodic reactor cleaning operations, ensuring the continuous and stable progress of the "polymerization-viscosity increase-spinning" process, reducing production costs and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0028] Figure 1 This is a diagram showing the coordination relationship of the dual reactors in parallel in this application;

[0029] Figure 2 This is a structural diagram of the dual reactors in parallel of the present application;

[0030] Figure 3 This is a diagram of the use of two reactors in parallel in this application;

[0031] Figure 4 It is a top view of the dual reactors in parallel of the present application;

[0032] Figure 5 This is a schematic diagram of the structure of a linear arrangement of multiple reactors (taking four reactors as an example) in this application;

[0033] Figure 6 This is a top view schematic diagram of a linear arrangement of multiple reactors (taking four reactors as an example) in this application;

[0034] Figure 7 This is a schematic diagram of the structure of a rectangular arrangement of multiple reactors (taking four reactors as an example) in this application;

[0035] Figure 8 This is a top view schematic diagram of a rectangular arrangement of multiple reactors (taking four reactors as an example) in this application;

[0036] Figure 9 This is a schematic structural diagram of a ring-shaped arrangement of multiple reactors (taking four reactors as an example) in this application;

[0037] Figure 10 This is a top view schematic diagram of a circular arrangement of multiple reactors (taking four reactors as an example) in this application.

[0038] Reference numerals in the figure: A. Feed zone; B: Reaction zone; C: Discharge zone; 1. Feed main pipe; 2. First connecting piece; 3. Feed valve; 301. First feed valve; 302. Second feed valve; 4. Feed branch pipe; 5. Feed melt gear pump; 501. First feed melt gear pump; 502. Second feed melt gear pump; 6. Feed pipe; 7. Polycondensation reactor; 701. First polycondensation reactor; 702. Second polycondensation reactor; 703. Third polycondensation reactor; 704. Fourth polycondensation reactor; 8. Discharge pipe; 9. Discharge melt gear pump; 901. First discharge melt gear pump; 902. Second discharge melt gear pump; 10. Discharge branch pipe; 11. Discharge valve; 1101. First discharge valve; 1102. Second discharge valve; 12. Second connecting piece; 13. Discharge main pipe; 14. Waste pipe and waste valve; 1401. First waste pipe and waste valve; 1402. Second waste pipe and waste valve; 15. Waste pipe; 1501. First waste pipe; 1502. Second waste pipe; 16. Diversion pipe. DETAILED DESCRIPTION

[0039] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, the technical solutions in the embodiments of this application will be further described in detail below in conjunction with the drawings in the embodiments of this application. It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit the technical solutions of this application. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of this application.

[0040] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it may be located directly or indirectly on the other component. When a component is referred to as being "connected to" another component, it may be directly or indirectly connected to the other component. The directions or positions indicated by the terms "upper," "lower," "left," "right," "front," "back," "vertical," "horizontal," "top," "bottom," "inside," and "outside" are based on the directions or positions shown in the accompanying drawings and are for ease of description only. They should not be construed as limitations on the present technical solution.

[0041] In addition, the terms "first" and "second" are used only for descriptive purposes and should not be understood as indicating or implying relative importance or implicitly specifying the number of technical features. "Multiple" means two or more, unless otherwise specifically defined.

[0042] Example 1

[0043] This embodiment is a reaction device with two vertical polycondensation reactors in parallel. Figure 1As shown, this embodiment is divided into a feed zone A, a reaction zone B and a discharge zone C. The three zones cooperate to realize the process of raw material melt from low viscosity melt input to high viscosity melt output.

[0044] Specifically, combined with Figure 2 and Figure 3 The specific settings of the devices contained in each partition and their coordination relationships are as follows:

[0045] The main function of the feed zone A is to distribute and transport the low-viscosity melt into the corresponding polycondensation reactor 7. Along the melt flow direction, the following components are arranged in sequence: the feed main pipe 1, the first connecting piece 2, the feed valve 3, the feed branch pipe 4, the feed melt gear pump 5, and the feed pipe 6. The first connecting piece 2 is a tee. The main functions of the first connecting piece 2 and the feed valve 3 are to adjust the flow state and flow direction of the melt in the feed main pipe 1. The main function of the feed melt gear pump 5 is to control the flow rate of the low-viscosity polyester melt in the feed zone A, thereby adjusting the feed rate in the polycondensation reactor 7 and maintaining the balance of the melt level in the polycondensation reactor 7.

[0046] The main function of the reaction zone B is to provide a platform for the melt polycondensation reaction of the low-viscosity polyester melt, which includes a first polycondensation reactor 701 and a second polycondensation reactor 702. The first polycondensation reactor 701 and the second polycondensation reactor 702 are arranged linearly.

[0047] The primary function of the discharge zone C is to transport the high-viscosity polyester melt after the melt polycondensation reaction. Discharge pipe 8, discharge melt gear pump 9, discharge branch pipe 10, discharge valve 11, second connecting piece 12, and discharge main pipe 13 are arranged in sequence along the melt flow direction. The discharge melt gear pump 9 primarily controls the flow rate of the high-viscosity polyester melt in the discharge zone, thereby adjusting the discharge rate from the polycondensation reactor 7. The second connecting piece 12 also utilizes a tee. The discharge valve 11 and second connecting piece 12 primarily regulate the flow state and direction of the high-viscosity polyester melt in the discharge branch pipe.

[0048] Between the discharging melt gear pump 9 and the discharging valve 11, on the discharging branch pipe 10 close to the side of the discharging valve 11, a waste pipe 14 and a waste pipe waste valve 15 are set to discharge the waste in the condensation reactor 7.

[0049] The above device can realize the following production and reactor cleaning operations:

[0050] (1) Normal production process

[0051] When the parallel vertical melt polycondensation reactor device is in production, one polycondensation reactor is in normal production and the other polycondensation reactor is idle. Figure 3As shown, the first polycondensation reactor 701 is operating normally, while the second polycondensation reactor 702 is idle. A low-viscosity melt flows along the feed main pipe 1 through the first connecting piece 2. The first feed valve 301 is open, and the second feed valve 302 is closed, allowing the low-viscosity melt to flow toward the first polycondensation reactor 701. The low-viscosity melt flows along the feed branch pipe 4 through the first feed melt gear pump 501. The power of the first feed melt gear pump 501 can be adjusted to control the melt flow rate in the feed zone and the feed rate into the first polycondensation reactor 701.

[0052] After the low-viscosity melt undergoes a melt polycondensation reaction in the first polycondensation reactor 701, a high-viscosity melt with a specific viscosity is formed and flows out of the first polycondensation reactor 701. It flows through the discharge pipe 8 and passes through the first discharge melt gear pump 901. The power of the first discharge melt gear pump 901 can be adjusted to control the discharge rate of the high-viscosity melt from the first polycondensation reactor 701. At this time, the first discharge valve 1101 is in the open state, and the waste pipe discharge valve 1401 is in the closed state. The high-viscosity melt flows along the melt branch pipe 10 on the side of the first polycondensation reactor 701, through the second connecting piece 12, into the discharge main pipe 13, and then flows out of the discharge area C for downstream production.

[0053] While the first polycondensation reactor 701 is in production, the second feed valve 302, the second discharge valve 1102, the waste pipe discharge valve 1402, the second feed melt gear pump 502 and the second discharge melt gear pump 902 are all in the closed state. At this time, the second polycondensation reactor 702 is in an independent state, and it and its supporting equipment can be cleaned, inspected, maintained and serviced.

[0054] (2) Reactor switching process

[0055] When the quality of the high-viscosity melt produced by the first polycondensation reactor 701 fluctuates or the spinning conditions in the subsequent process deteriorate, the first polycondensation reactor 701 needs to be shut down for kettle cleaning. At this time, the first polycondensation reactor 701 and the second polycondensation reactor 702 should be switched.

[0056] First, reduce the opening of the first feed valve 301 to reduce its feed rate, and simultaneously open the second feed valve 302 and the second feed melt gear pump 502, allowing the low-viscosity melt to slowly enter the second polycondensation reactor 702 along the feed branch pipe 4 and feed pipe 6, and to be piled in the reactor. Secondly, after the melt level in the second polycondensation reactor 702 reaches the preset value, open the second discharge melt gear pump 902 and the waste pipe discharge valve 1402 to discharge the unstable head material in the second polycondensation reactor 702. Then, when the quality of the material flowing out of the waste pipe stabilizes, close the waste pipe discharge valve 1402 and open the second discharge valve 1102, allowing the high-viscosity melt flowing out of the second polycondensation reactor 702 to begin flowing to the discharge main pipe 13. Finally, slowly reduce the opening and power of the first feed valve 301 and the first feed melt gear pump 501 until they are closed. At the same time, slowly increase the opening and power of the second feed valve 302 and the second feed melt gear pump 502 until they open to the preset value. After the highly viscous melt in the first polycondensation reactor 701 is completely discharged, slowly reduce the opening and power of the discharge melt gear pump 901 and the first discharge valve 1101 until they are closed. At the same time, slowly increase the opening and power of the second discharge melt gear pump 902 and the second discharge valve 1102 until they open to the preset value, and the reactor switching process is completed.

[0057] (3) Reactor cleaning process

[0058] After the reactor switching process is complete, the second polycondensation reactor 702 resumes production, while the first polycondensation reactor 701 remains idle and independent. At this point, cleaning and maintenance work can be performed on the first polycondensation reactor 701 while the second polycondensation reactor 702 maintains normal production, without affecting the normal production of the upstream polymerization workshop and the downstream spinning workshop.

[0059] The above-mentioned device is also applicable to a plurality of (two or more) reactors connected in parallel. For a device containing three or more (including three) polycondensation reactors connected in parallel, different arrangement methods need to be considered, including linear arrangement and annular arrangement, wherein the annular arrangement may include circular arrangement and rectangular arrangement.

[0060] by Figure 5 and Figure 6Taking the four reactors shown as an example, by installing a diverter tee on the feed branch pipe 4 (a tee + diverter pipe 16 + valve, or just a diverter pipe 16 + valve is sufficient; the tee and valve adopt conventional structures, not shown in the figure), one feed main pipe 1 corresponds to two feed branch pipes 3, four feed melt gear pumps 5, four feed pipes 6, and four melt reactors 7. In this solution, the diverter pipe 16 is arranged along the length of the feed branch pipe 4, and the first polycondensation reactor 701, the second polycondensation reactor 702, the third polycondensation reactor 703, and the fourth polycondensation reactor 704 are arranged linearly.

[0061] And in Figure 7 and Figure 8 In the four-reactor structure shown, although it also includes four melt reactors 7 and a diverter tee is provided on the feed branch pipe 4, the diverter pipe 16 is arranged to cross the feed branch pipe 4 (the crossing angle in the figure is 90°, and the diverter pipe 16 is arranged perpendicular to the feed branch pipe 4), and the first polycondensation reactor 701, the second polycondensation reactor 702, the third polycondensation reactor 703, and the fourth polycondensation reactor 704 are arranged in a rectangular shape.

[0062] exist Figure 9 and Figure 10 The four-reactor structure shown also includes four melt reactors 7, but both the first connecting piece 2 and the second connecting piece 12 are five-way (a conventional five-way structure, not shown). In this case, four feed branch pipes 3 are provided, corresponding to four feed melt gear pumps 5, four feed pipes 6, and four melt reactors 7. The first polycondensation reactor 701, the second polycondensation reactor 702, the third polycondensation reactor 703, and the fourth polycondensation reactor 704 are arranged in a ring.

[0063] The above description is only a preferred embodiment of the present application and does not limit the present application in any form or substance. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the method of the present application, and these improvements and supplements should also be regarded as the scope of protection of the present application. Any technician familiar with this profession can make some changes, modifications and evolutions of the technical content disclosed above without departing from the spirit and scope of the present application, which are equivalent embodiments of the present application; at the same time, any changes, modifications and evolutions of any equivalent changes made to the above embodiments based on the essential technology of the present application still fall within the scope of the technical solution of the present application. In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application clearer, the technical solutions in the embodiments of the present application will be further described in detail in conjunction with the drawings in the embodiments of the present application. It should be understood that the specific embodiments described here are only used to explain the present application and are not used to limit the technical solutions of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work fall within the scope of protection of the present application.

Claims

1. A parallel vertical melt polycondensation reaction device, characterized in that: It includes a feed main pipe, a first connecting piece, a feed branch pipe, a feed melt gear pump, a polycondensation reactor, a discharge melt gear pump, a discharge branch pipe, a second connecting piece, and a discharge main pipe. There are at least two feed branch pipes, and the number of feed melt gear pumps, polycondensation reactors, and discharge melt gear pumps are all arranged corresponding to the number of feed branch pipes; The feed main pipe is connected to the feed branch pipe via a first connecting piece, and a feed valve is provided on the feed branch pipe; The feed branch pipe is connected to the feed pipe via a feed melt gear pump, and the feed pipe is communicated with the polycondensation reactor; The polycondensation reactor is connected to a discharge pipe, and the discharge pipe is connected to a discharge branch pipe via a discharge melt gear pump; The discharge branch pipe is provided with a discharge valve; Each discharge branch pipe is connected to the discharge main pipe through a second connecting piece; Control the different on and off of the feed valve and discharge valve to realize the parallel connection of each polycondensation reactor; The multiple polycondensation reactors in the above structure work simultaneously, and at this time, all the feed valves and discharge valves are open; Alternatively, at least one of the polycondensation reactors in the above configuration is working and at least one is idle. At this time, the feed valve and the discharge valve corresponding to the idle polycondensation reactor are closed.

2. A parallel vertical melt polycondensation reaction device according to claim 1, characterized in that: The discharge branch pipe is provided with a waste discharge pipe, and a waste discharge valve is provided on the waste discharge pipe to realize the waste discharge of the material in the discharge branch pipe.

3. The parallel vertical melt polycondensation reaction device according to claim 1, characterized in that: The polycondensation reactor is a vertical falling film melt polycondensation reactor, with a feed port at the top and a discharge port at the bottom.

4. The parallel vertical melt polycondensation reaction device according to claim 1, characterized in that: The melt gear pump is any one of a straight tooth type, a helical tooth type, and a herringbone tooth type.

5. The parallel vertical melt polycondensation reaction device according to claim 1, characterized in that: The first connecting piece and the second connecting piece are both three-way pipe fittings, two feed branches are provided, and two corresponding feed valves, feed melt gear pumps, polycondensation reactors, discharge melt gear pumps, discharge branches, and discharge valves are also provided. The two polycondensation reactors are arranged in parallel.

6. The parallel vertical melt polycondensation reaction device according to claim 1, characterized in that: The first connecting piece and the second connecting piece are both five-way pipe fittings, there are four feed branches, and there are four corresponding feed valves, feed melt gear pumps, polycondensation reactors, discharge melt gear pumps, discharge branches, and discharge valves. The four polycondensation reactors are arranged in parallel.

7. The parallel vertical melt polycondensation reaction device according to claim 6, characterized in that: The four polycondensation reactors are distributed in a ring shape relative to the feed main pipe.

8. A parallel vertical melt polycondensation reaction device according to any one of claims 1 to 7, characterized in that: At least one diversion tee pipe is provided on the feed branch pipe, one end of the diversion tee pipe is connected to the feed branch pipe, and the other two ends are respectively connected to a melt reactor, forming a parallel structure including multiple polycondensation reactors.

9. The parallel vertical melt polycondensation reaction device according to claim 8, characterized in that: The polycondensation reactors are arranged linearly along the length direction of the feed branch pipe.

10. The parallel vertical melt polycondensation reaction device according to claim 8, characterized in that: The polycondensation reactors are arranged in a rectangular shape.

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