Device and method for preparing recycled monomer of polyester raw material

Abstract

The present invention relates to a device and method for preparing recycled monomers from polyester raw materials, and belongs to the technical field of polyester raw material preparation. It mainly includes a bracket, a shell, a cover and functional components. The shell is fixed by a bracket, and a separation chamber composed of a rotatable separation inner barrel is provided inside, and a sealed cover is configured on the top. The driving mechanism drives the separation inner barrel to rotate, and the balanced heating unit adopts a heating component and an isolation cover combination arranged at an axial position to achieve uniform temperature control. The cover has a built-in rotating support unit, which includes a plurality of support arms with support wheels and a linkage mechanism. When the cover is closed, the linkage mechanism presses down the isolation cover to trigger the support wheels to abut against the upper wall of the inner tank, thereby enhancing the rotation stability. The pressurizing unit is arranged on the inner side of the cover, and a pressure chamber is formed by an annular cover plate with air holes and a containing groove to maintain the reaction pressure. This device effectively controls the temperature and pressure stability of the reaction system through the synergistic effect of rotary heating and dynamic pressurization, thereby improving the liquid phase quality of polyester depolymerization and regeneration monomers.

Description

Technical Field

[0001] The invention relates to a device and method for preparing polyester raw material recycled monomers, belonging to the technical field of polyester raw material preparation. Background Art

[0002] Due to its excellent properties, polyethylene terephthalate (PET) is widely used in beverage bottles, food packaging, fibers, and films, resulting in huge consumption and waste generation. Traditional treatment methods face severe challenges:

[0003] Limitations of physical recycling: Traditional physical recycling (melt recycling) involves washing and shredding waste PET before direct melt spinning or injection molding. This method, due to repeated thermal processing, can lead to polymer chain degradation and reduced material properties (such as decreased viscosity and yellowing). This method has a limited recycling cycle and is difficult to use in high-quality food contact applications, typically requiring only "downgrading."

[0004] Environmental pressures: Large amounts of discarded PET end up in landfills or incinerators, wasting land resources and causing secondary pollution (such as greenhouse gases and hazardous substances produced by incineration). Marine plastic pollution is becoming increasingly serious, of which PET is a major component.

[0005] Waste of resources: The raw materials of PET (terephthalic acid (TPA) and ethylene glycol (EG)) are mainly derived from non-renewable petroleum resources. Waste of PET is the waste of precious carbon resources.

[0006] The inventors have discovered that the prior art has at least the following technical problems:

[0007] In conventional methanolysis processes, the alcoholysis reaction typically occurs under high temperature and pressure. To separate the solid-liquid mixture after the reaction, equipment such as a horizontal spiral centrifuge is often used. However, when the high-temperature, high-pressure material enters a centrifuge operating at normal pressure without insulation and heating, a dramatic drop in pressure and temperature occurs. This leads to two serious problems:

[0008] Too rapid a temperature drop causes product precipitation: The target product in the liquid phase (such as DMT or its intermediate BHET) has a higher solubility at high temperatures. When the temperature drops rapidly, its solubility decreases, causing it to crystallize and precipitate prematurely during the separation process and mix into the semi-solid residue that should have been separated, resulting in the loss of valuable products.

[0009] Sudden pressure drops reduce material separation efficiency: When high-pressure materials enter a normal-pressure environment, they experience "flash evaporation," affecting separation stability. Simultaneously, a drop in temperature increases liquid viscosity and impairs fluidity, significantly reducing centrifugal separation efficiency and precision. Ultimately, the separated liquid product has low purity and high impurity content, impacting the load of subsequent purification steps and final product quality. Summary of the Invention

[0010] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a device for preparing polyester raw material recycled monomers, which avoids excessive temperature and pressure drops, thereby reducing the quality of the liquid phase.

[0011] The polyester raw material recycled monomer preparation device of the present invention comprises:

[0012] Bracket;

[0013] The shell is connected to the bracket and is internally rotatably connected to the separation inner barrel. A separation cavity is provided in the shell corresponding to the separation inner barrel.

[0014] A cover body is arranged at the upper end of the shell and forms a sealed connection with the shell;

[0015] A driving mechanism is provided on the housing and is used to drive the separation inner barrel to rotate;

[0016] The balanced heating unit includes a heating component connected to the axis of the separated inner barrel, and an isolation cover is provided on the outside of the heating component;

[0017] A rotation support unit is provided inside the cover body, and the rotation support unit is used to rotationally support the upper inner wall of the separation inner barrel. The rotation support unit includes a plurality of support arms installed in the cover body, and support wheels are provided at the ends of the support arms. The support wheels are used to abut against the upper inner wall of the separation inner barrel. A linkage mechanism for controlling the movement of the support arms is also provided in the middle of the inner side of the cover body. When the cover body falls to close, the linkage mechanism presses down on the isolation cover, thereby controlling the movement of the support arms;

[0018] A pressurizing unit is provided inside the cover body for pressurizing the inside of the separated inner barrel. The pressurizing unit includes a receiving groove provided on the upper wall of the inner side of the cover body, an annular cover plate is fixed outside the receiving groove, and air holes are evenly opened on the annular cover plate.

[0019] Furthermore, a support ring is connected to the upper inner wall of the separation inner barrel, and the support wheel abuts against the support ring.

[0020] Furthermore, a guide piece is provided at the end of the support ring, a plurality of drainage grooves are provided on the guide piece, and the guide piece is correspondingly arranged below the air hole.

[0021] Furthermore, the linkage mechanism includes a support seat provided corresponding to the support arm, the support arm is slidably connected to the support seat, the support seat is connected to the inner wall of the cover body, a guide column is provided in the middle of the inner wall of the cover body, a pressure plate is slidably connected to the guide column, a first compression spring is mounted on the guide column between the pressure plate and the cover body, the pressure plate and the support arm are hingedly connected by a connecting rod, and a second compression spring is elastically connected between the support arm and the support seat.

[0022] Furthermore, a cylindrical seat is coaxially provided in the separated inner barrel, and a heating component is connected to the cylindrical seat. The heating component includes a heating frame, and a plurality of separately arranged heating cavities are provided on the outer ring of the heating frame. Infrared heating tubes are installed in the heating cavities, and a reflective film is provided on the inner wall of the heating cavity. An isolation cover is connected to the cylindrical seat, and the isolation cover is mounted on the outside of the infrared heating tube.

[0023] Furthermore, a connecting frame is provided at the lower end of the shell, and the shell is connected to the bracket through the connecting frame. A driving mechanism is installed at the lower end of the connecting frame. The driving mechanism includes a motor, and the output end of the motor is connected to a gearbox, which is connected to the lower end of the connecting frame. The output end of the gearbox is connected to a main shaft, and the main shaft is connected to the separation inner barrel.

[0024] Furthermore, a connecting sleeve is connected to the connecting frame, and a receiving tray is connected to the connecting sleeve. The receiving tray is located below the separated inner barrel, and a discharge port below the separated inner barrel is directly connected to the receiving tray.

[0025] Furthermore, a supporting sleeve is provided on the receiving tray, and the main shaft is rotatably connected to the supporting sleeve. The main shaft is connected to the supporting sleeve through a tapered bearing, and pressure rings are provided at both ends for axial positioning of the tapered bearing.

[0026] Furthermore, a temperature detection sensor is provided at the lower end of the separated inner barrel for detecting the temperature of the separated inner barrel, thereby adjusting the heating component.

[0027] The method for preparing recycled monomers from polyester raw materials of the present invention comprises the following steps:

[0028] Step 1: pretreatment of waste polyester;

[0029] Step 2: pressure alcoholysis reaction;

[0030] Step 3, using a polyester raw material regeneration monomer preparation device to centrifugally separate the solid-liquid mixture;

[0031] Step 4, liquid phase monomer purification;

[0032] Step 5: Residue disposal.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] This invention maintains high-temperature separation, avoids product loss, and improves yield: Through a built-in balanced heating unit, the device compensates for heat loss in real time during high-speed centrifugation, maintaining the target high temperature within the separation chamber. This effectively prevents premature crystallization of target products (such as DMT / BHET) dissolved in the liquid phase due to sudden temperature drops, preventing them from being mistakenly separated into the semi-solid residue, thereby significantly improving the recovery rate of the target monomer.

[0035] Achieve pressure-maintained separation, improving separation efficiency and product purity: Through the pressurization unit on the cover, this device can establish and maintain a certain backpressure within the separation chamber, preventing the material entering from the autoclave from experiencing a dramatic pressure drop. This not only avoids "flash evaporation" and ensures smooth material separation, but more importantly, maintaining high temperature and pressure effectively reduces the viscosity of the liquid phase and improves its fluidity, thereby greatly improving the efficiency and precision of centrifugal separation, resulting in a purer liquid product with lower impurity content.

[0036] Highly integrated structure, stable and reliable operation: This invention cleverly integrates heating, pressurization, and stable support functions into the vertical centrifuge structure. In particular, the linked rotating support unit automatically supports the high-speed rotating separation barrel when the lid is closed, enhancing the stability of the equipment. The centrally located heating assembly and annular pressurization vents ensure uniform temperature and pressure distribution within the separation chamber, ensuring stability and control of the entire separation process, and providing reliable support for industrial continuous and stable production. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is one of the structural diagrams of an embodiment of the present invention;

[0038] Figure 2 This is the second structural diagram of an embodiment of the present invention;

[0039] Figure 3 This is a schematic diagram of the structure of the separated inner barrel according to an embodiment of the present invention;

[0040] Figure 4 This is a schematic diagram of the lower end structure of the separation inner barrel according to an embodiment of the present invention;

[0041] Figure 5 1 is a schematic structural diagram of a heating assembly according to an embodiment of the present invention;

[0042] Figure 6 This is a schematic diagram of the rear structure of the hidden cover according to an embodiment of the present invention;

[0043] Figure 7 is a structural schematic diagram of a rotation support unit according to an embodiment of the present invention;

[0044] Figure 8 This is a front view of the cover body of the embodiment of the present invention in an open state;

[0045] Figure 9 yes Figure 8 A partial enlarged view of the middle part;

[0046] Figure 10 This is a left side view of the cover body of the embodiment of the present invention in an open state;

[0047] Figure 11 yes Figure 10 A partial enlarged view of point B in the middle;

[0048] Figure 12 This is a schematic diagram of the cover closing structure of an embodiment of the present invention;

[0049] Figure 13 This is one of the structural schematic diagrams of the cover in the closed state according to an embodiment of the present invention;

[0050] Figure 14 This is an embodiment of the present invention Figure 13 A partial enlarged view of point C in the middle;

[0051] Figure 15 This is a left side view of the cover and tank body of the embodiment of the present invention;

[0052] Figure 16 This is the second structural diagram of the cover in the closed state according to the embodiment of the present invention;

[0053] Figure 17 yes Figure 16 A partial enlarged view of point D in the middle;

[0054] Figure 18 This is one of the structural schematic diagrams of the receiving tray according to an embodiment of the present invention;

[0055] Figure 19 This is the second structural diagram of the receiving tray according to the embodiment of the present invention;

[0056] In the picture:

[0057] 1. Bracket;

[0058] 2. Shell; 21. Separation chamber; 22. Receiving tray; 221. Support sleeve; 222. Press ring; 23. Connecting frame; 24. Connecting sleeve;

[0059] 3. Separate inner barrel; 31. Positioning ring; 32. Support ring; 33. Guide plate; 331. Drainage groove; 34. Column seat;

[0060] 4. Cover body; 41. Sliding groove;

[0061] 5. Opening and closing mechanism; 51. Lifting cylinder; 52. Locking block; 53. Triangular unlocking block; 54. Lifting hydraulic cylinder; 55. Sliding column; 551. Positioning plate; 56. Unlocking cylinder;

[0062] 6. Balanced heating unit; 61. Heating assembly; 611. Heating rack; 612. Infrared heating tube; 62. Isolation cover; 63. Temperature detection sensor;

[0063] 7. Rotation support unit; 71. Support wheel; 72. Support arm; 73. Support seat; 74. Second compression spring; 75. Connecting rod; 76. Pressure plate; 77. First compression spring; 78. Guide column;

[0064] 8. Driving mechanism; 81. Motor; 82. Gearbox; 83. Spindle; 84. Tapered bearing;

[0065] 9. Pressurizing unit; 91. Annular cover; 92. Air hole. DETAILED DESCRIPTION

[0066] Example

[0067] like Figures 1 to 19 As shown, the polyester raw material recycled monomer preparation device of the present invention comprises:

[0068] Bracket 1;

[0069] The shell 2 is connected to the bracket 1 and is internally rotatably connected to the separation inner barrel 3. A separation chamber 21 is provided in the shell 2 corresponding to the separation inner barrel 3.

[0070] The upper end of the separation inner barrel 3 extends out of the shell 2, which makes it easy to clean the outer wall of the separation inner barrel 3 during later maintenance.

[0071] The cover 4 is provided at the upper end of the housing 2 and forms a sealed connection with the housing 2;

[0072] like Figure 14 As shown, the outer ring of the cover body 4 is provided with a cover opening and closing mechanism 5, which includes at least three lifting cylinders 51 arranged on the outer wall of the shell 2. The output end of the lifting cylinder 51 is used to lift the cover body 4. One end of the shell 2 is hingedly connected to the cover body 4. A sliding column 55 that can move up and down is connected to one side of the shell 2. A locking block 52 is hingedly connected to the shell 2 for when the sliding column 55 is raised to the top. When the sliding column 55 is raised to the top, the locking block 52 engages the positioning plate 551 at the lower end of the sliding column 55. At this time, the lifting hydraulic cylinder 54 installed on the positioning plate 551 is pulled out and becomes tilted at the same time (as shown in FIG. Figure 14 As shown), it is convenient to lift the cover 4, as shown Figure 6 and Figure 7 As shown, the output end of the lifting hydraulic cylinder 54 is connected to a hinged column, and a sliding groove 41 is correspondingly provided on the cover body 4. The hinged column is slidably connected to the sliding groove 41. When the cover body 4 falls, the lifting hydraulic cylinder 54 is sent back downward.

[0073] like Figure 11 or Figure 17 As shown, an unlocking cylinder 56 is also provided corresponding to the locking block 52 on the shell 2, and the output end of the unlocking cylinder 56 is connected to the triangular unlocking block 53. When the cover body 4 needs to be lowered, the unlocking cylinder 56 is actuated, and the locking block 52 is pushed open through the triangular unlocking block 53, thereby causing the positioning plate 551 to fall and move.

[0074] The driving mechanism 8 is provided on the housing 2 and is used to drive the separation inner barrel 3 to rotate;

[0075] The balanced heating unit 6 includes a heating component 61 connected to the axis of the separated inner barrel 3, and an isolation cover 62 is sheathed on the outside of the heating component 61;

[0076] A rotation support unit 7 is provided inside the cover body 4. The rotation support unit 7 is used to rotationally support the upper inner wall of the separation inner barrel 3. The rotation support unit 7 includes a plurality of support arms 72 installed in the cover body 4. The end of the support arm 72 is provided with a support wheel 71. The support wheel 71 is used to abut against the upper inner wall of the separation inner barrel 3. A linkage mechanism for controlling the movement of the support arm 72 is also provided in the middle of the inner side of the cover body 4. When the cover body 4 falls to close, the linkage mechanism presses down on the isolation cover 62, thereby controlling the movement of the support arm 72.

[0077] A pressurizing unit 9 is provided inside the cover body 4 for pressurizing the interior of the separated inner barrel 3. The pressurizing unit 9 includes a receiving groove provided on the upper wall of the inner side of the cover body 4. An annular cover plate 91 is fixed to the outside of the receiving groove, and air holes 92 are evenly opened on the annular cover plate 91.

[0078] like Figure 2 As shown, an air inlet nozzle is provided at the upper end of the cover body 4, and the air inlet nozzle is connected to the receiving groove, so that the inert gas is sent from the air inlet nozzle into the annular receiving groove, and then sent into the separation inner barrel 3 through the air hole 92 on the annular cover plate 91.

[0079] A support ring 32 is connected to the upper inner wall of the separation inner barrel 3 , and the support wheel 71 abuts against the support ring 32 .

[0080] A positioning ring 31 is welded on the inner ring of the separation inner barrel 3, and the positioning ring 31 extends inward by one end to prevent the liquid from entering the area of ​​the support ring 32 during the separation process. The upper end of the positioning ring 31 is used to install the support ring 32, and the support ring 32 is placed on the positioning ring 31, and support is formed by the positioning ring 31. The inner ring of the support ring 32 is locked to the inner wall of the separation inner barrel 3 by screws.

[0081] A guide piece 33 is provided at the end of the support ring 32 . A plurality of drainage grooves 331 are provided on the guide piece 33 . The guide piece 33 is correspondingly arranged below the air hole 92 .

[0082] The drainage groove 331 is opened in a spiral shape. When the separation inner barrel 3 rotates, the gas entering from the upper end air hole 92 is sent into the separation inner barrel 3 through the drainage groove 331, thereby forming a certain internal pressure. The design of the drainage groove 331 can better ensure the uniformity of the internal gas temperature, thereby improving the stability of the separation.

[0083] The linkage mechanism includes a support seat 73 corresponding to the support arm 72, the support arm 72 is slidably connected to the support seat 73, the support seat 73 is connected to the inner wall of the cover body 4, a guide column 78 is provided in the middle of the inner wall of the cover body 4, a pressure plate 76 is slidably connected to the guide column 78, a first compression spring 77 is mounted on the guide column 78 between the pressure plate 76 and the cover body 4, the pressure plate 76 and the support arm 72 are hingedly connected by a connecting rod 75, and a second compression spring 74 is elastically connected between the support arm 72 and the support seat 73.

[0084] A cylindrical seat 34 is coaxially provided in the separated inner barrel 3, and a heating component 61 is connected to the cylindrical seat 34. The heating component 61 includes a heating frame 611. The outer ring of the heating frame 611 is provided with several separately arranged heating chambers. An infrared heating tube 612 is installed in the heating chamber, and a reflective film is provided on the inner wall of the heating chamber. An isolation cover 62 is connected to the cylindrical seat 34, and the isolation cover 62 is sleeved on the outside of the infrared heating tube 612.

[0085] A connecting frame 23 is provided at the lower end of the shell 2, and the shell 2 is connected to the bracket 1 through the connecting frame 23. A driving mechanism 8 is installed at the lower end of the connecting frame 23. The driving mechanism 8 includes a motor 81. The output end of the motor 81 is connected to a gearbox 82. The gearbox 82 is connected to the lower end of the connecting frame 23. The output end of the gearbox 82 is connected to a main shaft 83, and the main shaft 83 is connected to the separation inner barrel 3.

[0086] The connecting frame 23 is connected to a connecting sleeve 24 , and the connecting sleeve 24 is connected to a receiving tray 22 . The receiving tray 22 is located below the separation inner barrel 3 , and a discharge port below the separation inner barrel 3 is directly connected to the receiving tray 22 .

[0087] A support sleeve 221 is provided on the receiving tray 22, and the main shaft 83 is rotatably connected to the support sleeve 221. The main shaft 83 is connected to the support sleeve 221 through a tapered bearing 84, and pressure rings 222 are provided at both ends for axial positioning of the tapered bearing 84.

[0088] A temperature detection sensor 63 is provided at the lower end of the separation inner barrel 3 for detecting the temperature of the separation inner barrel 3 so as to adjust the heating component 61 .

[0089] The method for preparing polyester raw material recycled monomers of the present invention comprises the following steps:

[0090] Step 1: Pretreatment of waste polyester (PET)

[0091] 1. Sorting and impurity removal: Recycled waste PET bottles and packaging are sorted manually or automatically to remove non-PET impurities such as bottle caps (HDPE / PP), labels (PVC / PS / paper), and metal rings.

[0092] 2. Cleaning and crushing: The sorted PET is cleaned to remove surface dirt, glue, residue, etc. It is then crushed into 10-15mm PET flakes by a crusher.

[0093] 3. Flotation and Drying: Utilizing density differences, impurities such as polyolefins (PP / PE) with a density lower than that of water are further removed through water washing and flotation. Finally, the clean PET chips are dried to remove moisture, as water can interfere with the subsequent alcoholysis reaction.

[0094] Step 2: Pressurized alcoholysis reaction

[0095] 1. Feeding: Add the pretreated dry PET fragments, alcoholysis agent (such as methanol or ethylene glycol) and catalyst (such as zinc acetate, antimony oxide, etc.) into the high temperature and high pressure reactor in a certain proportion.

[0096] 2. Reaction: Seal the reactor, increase the temperature and pressure (e.g., 180-280°C, 1-4 MPa). The PET macromolecular chains undergo depolymerization under the action of the alcohol and catalyst.

[0097] 3. If methanol is used, it is methanolysis, and the main products are dimethyl terephthalate (DMT) and ethylene glycol (EG).

[0098] If ethylene glycol is used, it is glycolysis, and the main product is bis(2-hydroxyethyl) terephthalate (BHET).

[0099] 4. Completion of the reaction: After the reaction is completed, a high-temperature and high-pressure solid-liquid mixture containing the liquid target product (dissolved DMT or BHET), excess alcoholysis agent, catalyst and semi-solid residue (such as pigments, additives, unreacted PET, etc.) is formed in the kettle.

[0100] Step 3: Use this device for high temperature and high pressure centrifugal separation

[0101] The high-temperature, high-pressure solid-liquid mixture produced in step 2 is fed directly into the polyester raw material regeneration monomer production apparatus described herein without significantly reducing the temperature and pressure. The apparatus rotates at high speed while maintaining a high temperature (e.g., 150-250°C) and a certain back pressure (e.g., 0.5-2 MPa) to achieve efficient solid-liquid separation.

[0102] Liquid phase: mainly the alcoholysis agent solution in which the target monomer (DMT or BHET) is dissolved, enters the separation chamber 21 from the separation inner barrel 3, and is discharged from the liquid outlet at the lower end of the separation chamber 21.

[0103] Semi-solid phase: mainly catalysts, pigments, inorganic additives, unreacted residues and other residues, which are discharged from the discharge port at the lower end of the separation inner barrel 3 to the receiving tray 22.

[0104] Step 4: Liquid Phase Monomer Purification

[0105] Rectification / Distillation: The separated liquid phase is distilled to first recover the excess alcoholysis agent (methanol or ethylene glycol) for recycling.

[0106] Crystallization and recrystallization: The remaining crude monomer (crude DMT or crude BHET) is crystallized by cooling, and soluble impurities are further removed through one or more recrystallization operations.

[0107] Filtration and drying: The purified crystals are filtered, washed and dried to obtain high-purity polymerization-grade regenerated monomer products (DMT or BHET).

[0108] Step 5: Residue disposal

[0109] Catalyst recovery: The semi-solid residue separated by centrifugation is processed to recover the valuable catalyst.

[0110] Energy / resource utilization: The remaining residue can be incinerated to recover heat energy, or used as filler for other industrial applications to achieve final disposal of the waste.

[0111] Working principle:

[0112] High temperature and high pressure separation principle:

[0113] Maintaining high temperatures: The balanced heating unit 6 at the center of the device is crucial. The heating assembly 61, specifically the infrared heating tube 612, radiates heat into the interior of the separation inner barrel 3. The isolation cover 62 protects the heating element from material contamination and helps evenly distribute heat, compensating for heat lost during the separation process. A temperature sensor 63 at the bottom monitors the chamber temperature in real time. A closed-loop control system precisely adjusts the heating power to ensure the separation process remains at the target high temperature. This ensures high solubility of the target monomer (DMT / BHET) in the liquid phase, preventing premature crystallization and contamination of the solid phase, thereby improving yield.

[0114] Maintaining High Pressure: The pressurizing unit 9 on the lid 4 is responsible for maintaining pressure. An inert gas, such as nitrogen, enters the containment tank within the lid through an inlet nozzle. It then enters the separation inner barrel 3 through evenly distributed air holes 92 on the annular cover plate 91. This annular, multi-porous air intake creates a stable and uniform pressure environment within the rotating chamber, effectively balancing the high pressure from the upstream reactor and preventing violent "flash" of material upon entry. Maintaining pressure also reduces liquid viscosity and improves fluidity, significantly enhancing the efficiency and precision of centrifugal separation.

[0115] High-speed rotation stabilization principle:

[0116] Bottom drive and support: The drive mechanism 8 drives the separation inner barrel 3 to rotate from the bottom through the main shaft 83. The main shaft is stably supported by the tapered bearing 84 and the support sleeve 221, ensuring the rotation accuracy of the bottom.

[0117] Top dynamic adaptive support: The upper part of a vertical centrifuge that rotates at high speed is prone to shaking. The rotating support unit 7 solves this problem. When the cover body 4 falls and closes, the linkage mechanism pressure plate 76 in its center will be pressed down (by contacting the top of the isolation cover 62), and the multiple support arms 72 will be pushed outward through the connecting rod 75. The support wheel 71 at the end of the support arm will accurately rest on the support ring 32 on the inner wall of the separation inner barrel 3. This forms a multi-point dynamic support on the upper part of the inner tank, which greatly suppresses the vibration during high-speed rotation and enhances the stability and safety of operation. When the cover body is opened, the second compression spring 74 and the first compression spring 77 act to automatically retract the support arm.

[0118] How it works together:

[0119] Heating, pressurization, rotation, and support systems work in tandem. Rotation generates a centrifugal field, the driving force for separation; heating and pressurization create the ideal physical and chemical environment for separation; and top dynamic support provides the mechanical guarantee for the stable operation of the first three systems under demanding conditions (high temperature, high pressure, and high speed). This integrated design ensures efficient, stable, and controllable separation.

[0120] Working process:

[0121] Preparation stage:

[0122] Check the condition of the equipment to ensure that all seals are intact and pipe connections are correct.

[0123] Connect the power supply, compressed air (for the cylinder), and inert gas (for the pressurizing unit).

[0124] Verify that downstream liquid and solid phase collection vessels are in place.

[0125] Startup and preheating:

[0126] The motor 81 in the driving mechanism 8 is started, so that the separation inner tub 3 starts to rotate at a relatively low speed.

[0127] The balanced heating unit 6 is started, the target separation temperature (eg, 200° C.) is set, and the separation chamber 21 is preheated. Meanwhile, the reading of the temperature detection sensor 63 is monitored.

[0128] Cover closing and system pressurization:

[0129] When the equipment is preheated to a temperature close to the target temperature, the opening and closing mechanism 5 (such as the lifting cylinder 51 , the lifting hydraulic cylinder 54 , etc.) is operated to steadily lower the cover 4 and seal it with the shell 2 .

[0130] During this process, the linkage mechanism of the rotation support unit 7 is triggered, and the support wheel 71 automatically extends and abuts against the support ring 32 .

[0131] Inert gas is introduced into the separation inner barrel 3 through the pressurizing unit 9 to make the internal pressure reach a preset back pressure value (such as 1.0 MPa).

[0132] Feeding and separation:

[0133] After confirming that the temperature, pressure and speed are stable at the set values, open the feed valve to continuously feed the high-temperature and high-pressure solid-liquid mixture from the upstream reactor into the high-speed rotating separation inner barrel 3.

[0134] Under the action of strong centrifugal force, the liquid phase enters the separation chamber 21 from the filter screen on the outer wall of the separation inner barrel 3.

[0135] After entering from the air hole 92 , the gas passes through the drainage groove 331 on the guide plate 33 , is guided and evenly distributed, and the pressure in the cavity is maintained stable.

[0136] Operation monitoring:

[0137] Throughout the separation process, various parameters on the control panel, such as temperature, pressure, motor current, speed and equipment vibration, are continuously monitored to ensure smooth operation.

[0138] Shutdown and discharge:

[0139] After the materials are separated, close the feed valve first.

[0140] Allow the equipment to continue operating for a period of time to ensure that the liquid phase of the material in the liner is separated and discharged (purge process).

[0141] The rotation speed of the driving mechanism 8 is gradually reduced until the separation inner barrel 3 completely stops rotating, and the semi-solid residual material is discharged into the receiving tray 22 for discharge.

[0142] Pressure relief and cooling:

[0143] Slowly open the exhaust valve to safely reduce the pressure in the separation inner barrel 3 to normal pressure.

[0144] Turn off the balanced heating unit 6 and let the equipment cool down naturally or start the cooling system (if any) to cool it down.

[0145] Opening and cleaning maintenance:

[0146] After the device has cooled to a safe temperature and there is no internal pressure, the opening and closing mechanism 5 is operated (by unlocking the cylinder 56, etc.) to open the cover 4. The rotating support unit 7 is then automatically retracted.

[0147] The interior of the separation inner barrel 3, the support ring 32 and other components are inspected and cleaned as necessary to prepare for the next operation.

[0148] The description of the direction and relative position relationship of the structure in the present invention, such as the description of front, back, left, right, up and down, does not constitute a limitation of the present invention and is only for the convenience of description.

Claims

1. A device for preparing polyester raw material recycled monomers, comprising: Bracket (1); The shell (2) is connected to the bracket (1) and is internally rotatably connected to the separation inner barrel (3). A separation chamber (21) is provided in the shell (2) corresponding to the separation inner barrel (3); A cover (4) is provided at the upper end of the housing (2) and forms a sealed connection with the housing (2); A driving mechanism (8) is provided on the housing (2) and is used to drive the separation inner barrel (3) to rotate; It is characterized in that A balanced heating unit (6) includes a heating component (61) connected to the axis of the separation inner barrel (3), and an isolation cover (62) is provided on the outside of the heating component (61); A rotation support unit (7) is provided inside the cover body (4), and the rotation support unit (7) is used to rotationally support the upper inner wall of the separation inner barrel (3), including a plurality of support arms (72) installed in the cover body (4), and a support wheel (71) is provided at the end of the support arm (72), and the support wheel (71) is used to abut against the upper inner wall of the separation inner barrel (3). A linkage mechanism for controlling the movement of the support arm (72) is also provided in the middle of the inner side of the cover body (4). When the cover body (4) falls to close, the linkage mechanism presses down on the isolation cover (62), thereby realizing the control of the movement of the support arm (72); A pressurizing unit (9) is provided in the cover body (4) for pressurizing the interior of the separation inner barrel (3). The pressurizing unit (9) comprises a receiving groove provided on the upper wall of the inner side of the cover body (4), an annular cover plate (91) is fixed to the outside of the receiving groove, and air holes (92) are evenly formed on the annular cover plate (91); A support ring (32) is connected to the upper inner wall of the separation inner barrel (3), and the support wheel (71) abuts against the support ring (32); A guide piece (33) is provided at the end of the support ring (32), and a plurality of drainage grooves (331) are provided on the guide piece (33), and the guide piece (33) is correspondingly arranged below the air hole (92); The linkage mechanism includes a support seat (73) corresponding to the support arm (72), the support arm (72) is slidably connected to the support seat (73), the support seat (73) is connected to the inner wall of the cover body (4), a guide column (78) is provided in the middle of the inner wall of the cover body (4), a pressure plate (76) is slidably connected to the guide column (78), a first compression spring (77) is mounted on the guide column (78) between the pressure plate (76) and the cover body (4), the pressure plate (76) and the support arm (72) are hingedly connected through a connecting rod (75), and a second compression spring (74) is elastically connected between the support arm (72) and the support seat (73).

2. The polyester raw material recycled monomer preparation device according to claim 1, characterized in that: A cylindrical seat (34) is coaxially provided in the separation inner barrel (3), a heating assembly (61) is connected to the cylindrical seat (34), the heating assembly (61) includes a heating frame (611), a plurality of separately arranged heating cavities are provided on the outer ring of the heating frame (611), an infrared heating tube (612) is installed in the heating cavity, a reflective film is provided on the inner wall of the heating cavity, an isolation cover (62) is connected to the cylindrical seat (34), and the isolation cover (62) is sleeved on the outside of the infrared heating tube (612).

3. The polyester raw material recycled monomer preparation device according to claim 1, characterized in that: A connecting frame (23) is provided at the lower end of the housing (2), and the housing (2) is connected to the bracket (1) through the connecting frame (23). A driving mechanism (8) is installed at the lower end of the connecting frame (23). The driving mechanism (8) includes a motor (81), an output end of the motor (81) is connected to a gearbox (82), the gearbox (82) is connected to the lower end of the connecting frame (23), and an output end of the gearbox (82) is connected to a main shaft (83), and the main shaft (83) is connected to the separation inner barrel (3).

4. The polyester raw material recycled monomer preparation device according to claim 3, characterized in that: The connecting frame (23) is connected to a connecting sleeve (24), and the connecting sleeve (24) is connected to a receiving tray (22). The receiving tray (22) is located below the separation inner barrel (3), and the discharge port below the separation inner barrel (3) is directly connected to the receiving tray (22).

5. The polyester raw material recycled monomer preparation device according to claim 4, characterized in that: A supporting sleeve (221) is provided on the receiving tray (22), and the main shaft (83) is rotatably connected to the supporting sleeve (221). The main shaft (83) is connected to the supporting sleeve (221) through a tapered bearing (84), and pressure rings (222) for axial positioning of the tapered bearing (84) are respectively provided at both ends.

6. The polyester raw material recycled monomer preparation device according to claim 1, characterized in that: A temperature detection sensor (63) is provided at the lower end of the separation inner barrel (3) for detecting the temperature of the separation inner barrel (3) and thereby adjusting the heating component (61).

7. A method for preparing recycled monomers from polyester raw materials, based on the device for preparing recycled monomers from polyester raw materials according to any one of claims 1 to 6, characterized in that: The steps include: Step 1: pretreatment of waste polyester; Step 2: pressure alcoholysis reaction; Step 3, using a polyester raw material regeneration monomer preparation device to centrifugally separate the solid-liquid mixture; Step 4, liquid phase monomer purification; Step 5: Residue disposal.

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