Polyester waste closed loop recycling device and method

Abstract

The application relates to a polyester waste closed-loop recycling device and method, and belongs to the polyester waste recycling technical field.The device comprises a tank body, a liftable centrifugal cylinder is arranged in the tank body, a circular discharge port is arranged at the lower end of the centrifugal cylinder, a balance heating mechanism and an output shaft with a clutch mechanism are arranged inside, a jacking mechanism is arranged at the lower part of the tank body, and the jacking mechanism comprises a telescopic cylinder, a sealing cylinder in sliding cooperation with the circular discharge port and a jacking column.The jacking mechanism is lifted to realize three functions in one action: first, the clutch mechanism is connected with an external power source to realize power sharing of upper and lower equipment, and energy consumption is greatly reduced;second, the sealing cylinder is cooperated with the circular discharge port to realize bottom plugging and opening, and the problem that solid impurities cannot be discharged from the top when a reaction kettle is directly connected with a lower separation kettle is solved;third, dynamic sealing is realized by using a spiral groove, and high-viscosity material abrasion is avoided.The application has compact structure, and effectively improves the closed-loop recycling efficiency of polyester waste.

Description

Technical Field

[0001] This invention relates to a closed-loop recycling and reuse device and method for polyester waste, belonging to the field of polyester waste recycling technology. Background Technology

[0002] In the closed-loop recycling process of polyester waste, after screening and crushing, the waste material usually enters the core reaction tank, where the reaction is accelerated by internal emulsifiers and other means. The resulting mixture then needs to enter the lower tank for solid-liquid separation (usually using centrifugal separation for purification).

[0003] In the process of realizing the technical solution of this application, the inventors discovered that the prior art has at least the following technical problems:

[0004] 1. Conventional bottom discharge structures face fatal sealing and jamming problems under "high temperature, high viscosity, and easy curing" conditions.

[0005] To ensure process continuity and reduce heat loss during material transport, the core reaction vessel is typically positioned directly above the separation vessel. Therefore, the separated solid impurities must be removed from below. Since the centrifuge is directly above the reaction vessel, the separated solid impurities cannot be removed from the top, necessitating a bottom discharge solution. While existing centrifuges employ bottom-discharge gates, flap valves, or bottom-discharge structures, polyester waste has extremely high viscosity and is typically in a high-temperature, semi-molten state, containing hard solid particles. If existing bottom-discharge models are directly applied, the connection between the discharge gate and the outlet must rely on traditional contact-type static seals (such as rubber rings or PTFE gaskets) or mechanical seals. Under the high-speed rotation of the centrifuge and the continuous scouring of high-viscosity, high-friction materials, hard particles easily become lodged in the seal gaps, causing severe wear and tear of the contact seals within a very short time, leading to serious leakage of high-temperature materials. Even more fatally, once the leaked high-viscosity polyester slurry penetrates the bottom rotating bearing or lifting transmission components, it will quickly solidify after cooling, causing the core moving parts of the equipment to completely jam, resulting in shutdown and paralysis, making maintenance and cleaning extremely difficult.

[0006] 2. Independent drive of upstream and downstream equipment results in a bulky structure and extremely high energy consumption.

[0007] The existing two-stage equipment (the core reactor above and the centrifuge below) is typically treated as two independent mechanical units, each requiring its own high-power drive motor and associated reduction gear, transmission, and bearing assemblies. This superposition of dual drive systems not only results in high overall equipment procurement costs and excessively limited vertical installation space, but also leads to enormous energy losses due to the independent operation of the two heavy-duty power systems. Furthermore, the presence of multiple transmission systems significantly increases the mechanical failure rate and daily maintenance costs of the production line. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a closed-loop recycling and reuse device and method for polyester waste. The aim is to solve the problems that the existing equipment cannot achieve bottom slag discharge under the condition of direct connection of top reactor, high energy consumption caused by multiple power sources, and poor sealing reliability at the dynamic and static joints in high viscosity environment.

[0009] The polyester waste closed-loop recycling and reuse device of the present invention includes:

[0010] The tank body has a centrifuge cylinder inside that can be raised and lowered along its axial direction, and a circular discharge port is opened at the lower end of the centrifuge cylinder;

[0011] A balanced heating mechanism is located inside the centrifuge cylinder and rises and falls synchronously with the centrifuge cylinder;

[0012] The output shaft has its lower end connected to the balanced heating mechanism, and its upper end is provided with a clutch mechanism for engaging and disengaging with the input shaft of an external power source.

[0013] A lifting mechanism, located at the lower part of the tank, is used to drive the lifting assembly consisting of the centrifuge drum, the balancing heating mechanism, and the output shaft to move up and down axially, so that the clutch mechanism can engage or disengage from the input shaft of the external power source.

[0014] The lifting mechanism includes:

[0015] A lifting frame is connected to the inner wall of the tank.

[0016] Telescopic cylinder, mounted on the lifting frame;

[0017] A sealing cylinder is connected to the output end of the telescopic cylinder, and the outer wall of the sealing cylinder is slidably fitted with the circular discharge port;

[0018] The lifting mechanism also includes a lifting column, which is located at the upper end of the sealing cylinder. The upper end of the lifting column is provided with an axial bearing. When the telescopic cylinder drives the sealing cylinder to rise, the upper end face of the axial bearing on the lifting column abuts against the lower end face of the balancing heating mechanism.

[0019] Preferably, the inner wall of the circular discharge port is provided with a spiral groove. When the centrifuge cylinder rotates, the spiral groove is used to transport the medium in the gap between the sealing cylinder and the circular discharge port upward to form a dynamic seal.

[0020] Preferably, the balancing heating mechanism includes a mounting frame, on which a heating housing is connected, and a heating source is provided inside the heating housing; the output shaft is connected to the mounting frame via a spline or involute key.

[0021] Preferably, an outer isolation cover is provided on the lower end face of the heating shell, and an inner isolation cover is connected to the outer surface of the lifting column, with the inner isolation cover arranged inside the outer isolation cover to form a sliding connection.

[0022] Preferably, an upper guide cylinder is coaxially connected to the upper end of the lifting frame, and the inner wall of the sealing cylinder is slidably connected to the upper guide cylinder.

[0023] Preferably, the lower end face of the balancing heating mechanism is provided with an annular guide groove, and the upper outer circumferential surface of the axial bearing is slidably sleeved in the annular guide groove.

[0024] Preferably, the tank is provided with a partition support cylinder, and the lower end of the outer wall of the centrifuge cylinder is provided with an annular support plate, and the partition support cylinder can support the annular support plate.

[0025] Preferably, the annular support plate has a downwardly extending drainage tube on its outer periphery.

[0026] This invention also discloses a closed-loop recycling and reuse method for polyester waste, comprising the following steps:

[0027] S1: Start the lifting mechanism until the clutch mechanism at the upper end of the output shaft engages with the input shaft of the external power source;

[0028] S2: Start the external power source and drive the centrifuge cylinder to rotate through the input shaft, clutch mechanism and output shaft;

[0029] S3: The material enters the centrifuge cylinder for centrifugal separation;

[0030] S4: After centrifugal separation is completed, the external power source is stopped, and the lifting mechanism is driven to lower the sealing cylinder, open the circular discharge port, and allow solid impurities to fall out; at the same time, the clutch mechanism is separated from the input shaft.

[0031] Preferably, in S3, the separated slurry enters the area between the centrifuge tube and the tank, and the slurry flows out continuously from the discharge pipe.

[0032] Compared with the prior art, the beneficial effects of the present invention are:

[0033] Bottom discharge is achieved by ingeniously combining the sealing cylinder with the circular discharge port at the bottom of the centrifuge cylinder through a bottom discharge and lifting mechanism. When centrifugation is complete and discharge is required, the telescopic cylinder retracts, the sealing cylinder descends to open the bottom channel, and the solid material is discharged directly from the bottom. This completely solves the industry problem of being unable to discharge material when the top of the equipment is occupied by reaction equipment, ensuring seamless vertical connection between upstream and downstream processes.

[0034] Power sharing significantly reduces energy consumption and costs: The lifting mechanism, while blocking the lower discharge port, simultaneously lifts the centrifuge cylinder, the balancing heating mechanism, and the output shaft upwards, allowing the clutch mechanism at the top of the output shaft to engage with the input shaft of the upper reaction equipment (external power source). This design eliminates the need for the original independent drive motor of the separation equipment, achieving power sharing between the upper and lower stages of equipment. This not only reduces procurement and maintenance costs but also greatly reduces the overall energy loss of the system.

[0035] Spiral dynamic seal solves the problem of leakage prevention in high-viscosity materials: Addressing the issue of static seal failure caused by polyester materials, this invention innovatively incorporates a spiral groove on the inner wall of the circular outlet. When the centrifuge drum rotates at high speed, this spiral groove acts like a miniature spiral pump, generating an upward conveying force that forcibly pushes the polyester medium that may have seeped into the sealing gaps back into the centrifuge drum, creating a "zero-wear" dynamic seal effect and significantly extending the equipment's service life.

[0036] Multiple protective designs ensure long-term operation of the core bearing: By setting an outer isolation cover at the lower end of the heating shell and an inner isolation cover on the outer surface of the lifting column, the two are nested to form a labyrinth sliding connection. At the same time, with the help of the annular guide groove, it effectively prevents the separated polyester slurry or liquid from splashing and invading into the axial bearing, avoiding bearing jamming caused by the solidification of high temperature and high viscosity materials. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of the present invention;

[0038] Figure 2 This is a schematic diagram of the omitted support platform structure of Embodiment 1 of the present invention;

[0039] Figure 3 yes Figure 2 Enlarged view of a portion of point A in the middle;

[0040] Figure 4 This is one of the schematic diagrams of the internal structure of the lifting mechanism in Embodiment 1 of the present invention before it is lifted;

[0041] Figure 5 This is the second schematic diagram of the internal structure of the lifting mechanism in Embodiment 1 of the present invention before it is lifted.

[0042] Figure 6 This is one of the schematic diagrams of the lifting mechanism after lifting in Embodiment 1 of the present invention;

[0043] Figure 7 This is the second schematic diagram of the lifting mechanism after lifting in Embodiment 1 of the present invention;

[0044] Figure 8 yes Figure 7 Enlarged view of a section at point B in the middle;

[0045] Figure 9 This is a schematic diagram of the internal structure of the upper cover plate of Embodiment 1 of the present invention (omitted);

[0046] Figure 10 yes Figure 9 Enlarged view of a section at point C;

[0047] Figure 11 yes Figure 9 Enlarged view of a section at point D;

[0048] In the picture:

[0049] 1. Tank body; 11. Divider support cylinder; 12. Top cover plate; 121. Support frame;

[0050] 2. Centrifuge cylinder; 21. Circular discharge port; 211. Spiral groove; 22. Annular support plate; 23. Drainage cylinder;

[0051] 3. Balanced heating mechanism; 31. Mounting bracket; 311. Positioning plate; 312. Flange; 32. Heating shell; 321. Outer isolation cover; 33. Heating source; 331. Infrared heating tube; 332. Connecting ring; 333. Conversion component; 334. Conductive ring; 335. Brush; 34. Annular guide groove; 35. Sealing cover plate; 351. Isolation sleeve;

[0052] 4. Output shaft;

[0053] 5. Clutch mechanism;

[0054] 6. Lifting mechanism; 61. Lifting frame; 611. Upper guide cylinder; 62. Telescopic cylinder; 63. Sealing cylinder; 64. Lifting column; 641. Inner isolation cover; 65. Axial bearing;

[0055] P, external power source; P1, input shaft;

[0056] 100. Core reaction vessel; 200. Support platform. Detailed Implementation

[0057] Example 1

[0058] like Figures 1 to 11 As shown, the closed-loop recycling and reuse device for polyester waste of the present invention mainly includes a tank 1, a centrifuge cylinder 2, a balanced heating mechanism 3, an output shaft 4, and a lifting mechanism 6.

[0059] This device is particularly suitable for placement directly below the core reaction tank 100, and is installed via a support platform 200 at the lower end of the core reaction tank 100. The tank body 1 serves as an external support and collection component, and contains a centrifuge cylinder 2 that can be raised and lowered along its axial direction. The centrifuge cylinder 2 is the core component for achieving solid-liquid separation, and its lower end has a circular discharge port 21 for discharging solid impurities downwards after the operation is completed.

[0060] A balancing heating mechanism 3 is provided inside the centrifuge drum 2, which rises and falls synchronously with the centrifuge drum 2. Specifically, the balancing heating mechanism 3 includes a mounting frame 31, on which a heating shell 32 is connected. The heating shell 32 contains a heating source 33 (such as an infrared heating tube 331 or a resistance heating element) to maintain the temperature of the polyester material during the separation process and prevent it from cooling and solidifying prematurely. A sealing cover plate 35 is screwed to the upper end of the mounting frame 31. An isolation sleeve 351 extends upward from the sealing cover plate 35. The isolation sleeve 351 passes through the upper cover plate 12 at the upper end of the tank body 1 and extends to the outside of the tank body 1. The upper end of the mounting frame 31 is provided with an upwardly extending flange 312, which is used to prevent material from falling into the upper end of the sealing cover plate 35. The heating source 33 includes an infrared heating tube 331 connected to the mounting bracket 31. The mounting bracket 31 is provided with a detachable positioning plate 311, which is used to position and install the upper end of the infrared heating tube 331. The positioning plate 311 is equipped with a connecting ring 332. The sealing cover plate 35 is provided with a conversion element 333. The lower end of the conversion element 333 passes through the sealing cover plate 35 and abuts against the connecting ring 332 through an elastic conductive sheet. The upper end of the sealing cover plate 35 has a conductive ring 334 installed on the isolation sleeve 351. The conductive ring 334 is connected to the elastic conductive sheet in the conversion element 333 through a wire. The upper cover plate 12 is provided with a support frame 121. The support frame 121 is equipped with a brush 335 that works with the conductive ring 334. Two brushes 335 are installed here to ensure that one is used and one is spare, thus ensuring the stability of the connection with the conductive ring 334.

[0061] The lower end of the output shaft 4 is connected to the mounting bracket 31 via a spline or involute key, which enables high-power torque transmission. The upper end of the output shaft 4 is equipped with a clutch mechanism 5, which is a plug-in clutch that engages after power failure. The clutch mechanism 5 can engage and disengage with the input shaft P1 of the external power source P (i.e., the stirring motor or other power output end of the reaction equipment above).

[0062] To achieve coordinated bottom discharge, sealing, and power engagement, this invention incorporates a lifting mechanism 6 at the lower part of the tank body 1. The lifting mechanism 6 includes a lifting frame 61 connected to the inner wall below the tank body 1. A telescopic cylinder 62 (such as a hydraulic cylinder or pneumatic cylinder) is fixedly mounted on the lifting frame 61; a hydraulic cylinder is used here to ensure stability. A sealing cylinder 63 is connected to the output end of the telescopic cylinder 62. The outer wall dimensions of the sealing cylinder 63 are adapted to the inner wall dimensions of the circular discharge port 21, forming a sliding fit between them.

[0063] Meanwhile, a lifting column 64 is provided at the upper end of the sealing cylinder 63, and an axial bearing 65 is installed at the upper end of the lifting column 64. An upper guide cylinder 611 is coaxially connected to the upper end of the lifting frame 61, and the inner wall of the sealing cylinder 63 is slidably connected to the upper guide cylinder 611 to ensure the verticality and stability of the lifting process.

[0064] Dynamic sealing and protective structure design:

[0065] When separating high-viscosity polyester waste, traditional static sealing rings are prone to wear and leakage. To address this, the present invention incorporates a spiral groove 211 machined into the inner wall of the circular outlet 21. When the centrifuge cylinder 2 is rotating, the sealing cylinder 63 remains stationary, and the spiral groove 211 rotates at high speed. Based on fluid mechanics principles, the rotating spiral groove 211 generates an upward pumping force (Archimedes' screw pump principle), forcibly pushing the trace amounts of medium entering the gap between the sealing cylinder 63 and the circular outlet 21 back into the centrifuge cylinder 2, thus forming a non-contact "dynamic seal," fundamentally solving the problems of leakage of high-viscosity materials and wear of the seals.

[0066] To protect the core axial bearing 65 from contamination by falling materials, an outer isolation cover 321 is provided on the lower end face of the heating shell 32, and an inner isolation cover 641 is connected to the outer surface of the lifting column 64. The inner isolation cover 641 is inserted into the outer isolation cover 321 to form a labyrinthine sliding connection. Furthermore, an annular guide groove 34 is provided on the lower end face of the balancing heating mechanism 3, and the upper outer circumferential surface of the axial bearing 65 is slidably fitted within the annular guide groove 34, serving a positioning function.

[0067] For liquid collection, the tank 1 is equipped with a partition support cylinder 11, and the lower end of the outer wall of the centrifuge cylinder 2 is equipped with an annular support plate 22. When the centrifuge cylinder 2 descends, the partition support cylinder 11 can support the annular support plate 22 to prevent the equipment from falling and being damaged. The outer periphery of the annular support plate 22 is equipped with a downward-extending guide cylinder 23. After the liquid slurry ejected by centrifugation crosses the edge along the inner wall of the centrifuge cylinder 2, it is guided downward by the guide cylinder 23 into the designated collection area.

[0068] Working process or working principle:

[0069] The closed-loop recycling and reuse method for polyester waste, combined with the apparatus of Example 1, has the following complete working principle:

[0070] 1. Lifting and power engagement preparation stage (corresponding to S1):

[0071] The telescopic cylinder 62 in the lifting mechanism 6 is activated, causing it to extend upwards. The telescopic cylinder 62 pushes the sealing cylinder 63 upwards, and the outer wall of the sealing cylinder 63 inserts into the circular discharge port 21 at the lower end of the centrifuge cylinder, completing the initial sealing of the lower circular discharge port. At the same time, the sealing cylinder 63 drives the lifting column 64 and the axial bearing 65 to move upwards. The upper end face of the axial bearing 65 abuts against the annular guide groove 34 on the lower end face of the balancing heating mechanism 3, thereby lifting the balancing heating mechanism 3, the centrifuge cylinder 2, and the output shaft 4 upwards as a whole. As the whole rises, the clutch mechanism 5 at the top of the output shaft 4 smoothly engages with the input shaft P1 of the external power source P.

[0072] 2. Rotational separation stage (corresponding to S2 and S3):

[0073] When the external power source P is started, the rotational power is transmitted to the output shaft 4 through the input shaft P1 and the clutch mechanism 5, which in turn drives the balancing heating mechanism 3 and the centrifuge cylinder 2 to rotate at high speed via the spline (at this time, the lifting column 64 and the sealing cylinder 63 remain stationary, and the axial bearing 65 bears the rotational friction). Polyester waste enters the centrifuge cylinder 2, and the heating source 33 maintains the flowability of the material. Under the action of centrifugal force, the pure liquid slurry overflows the edge of the centrifuge cylinder 2, is guided by the guide tube 23 to the area between the centrifuge cylinder 2 and the tank 1, and continuously flows out from the discharge pipe below, realizing product purification. During this process, the spiral groove 211 continuously plays a dynamic sealing role to prevent material from leaking out from the bottom gap.

[0074] 3. Shutdown and bottom discharge stage (corresponding to S4):

[0075] After centrifugal separation is completed, the external power source P is stopped. The telescopic cylinder 62 is retracted downwards, causing the sealing cylinder 63 and the lifting column 64 to descend. At this time, the centrifuge cylinder 2, due to its own weight (or the limitation of the guide component), descends a short distance and is then supported by the separating support cylinder 11, stopping its descent; while the sealing cylinder 63 continues to descend, thus completely separating from the circular discharge port 21, and the bottom channel is fully opened. Simultaneously, the output shaft 4 also descends, and the clutch mechanism 5 automatically separates from the input shaft P1. Finally, the solid impurities remaining inside the centrifuge cylinder 2 are no longer obstructed by the upper reactor and are directly discharged downwards from the opened circular discharge port 21 by gravity, completing the entire closed-loop recovery solid-liquid separation and discharge cycle.

[0076] The descriptions of the orientation and relative positional relationships of the structures in this invention, such as front, back, left, right, up, and down, do not constitute a limitation of this invention, but are merely for the convenience of description.

Claims

1. A closed-loop recycling and reuse device for polyester waste, characterized in that, include: The tank (1) has a centrifuge cylinder (2) inside which can be raised and lowered along its axis, and a circular discharge port (21) is opened at the lower end of the centrifuge cylinder (2). A balanced heating mechanism (3) is located inside the centrifuge cylinder (2) and moves up and down synchronously with the centrifuge cylinder (2); The output shaft (4) is connected to the balance heating mechanism (3) at its lower end. The upper end of the output shaft (4) is provided with a clutch mechanism (5) for engaging and disengaging with the input shaft (P1) of the external power source (P). The lifting mechanism (6) is located at the lower part of the tank (1) and is used to drive the lifting assembly consisting of the centrifuge cylinder (2), the balancing heating mechanism (3) and the output shaft (4) to move up and down axially so that the clutch mechanism (5) can engage or disengage from the input shaft (P1) of the external power source (P). The lifting mechanism (6) includes: A lifting frame (61) is connected to the inner wall of the tank (1); Telescopic cylinder (62) is mounted on the lifting frame (61); A sealing cylinder (63) is connected to the output end of the telescopic cylinder (62), and the outer wall of the sealing cylinder (63) is slidably fitted with the circular discharge port (21); The lifting mechanism (6) further includes a lifting column (64), which is located at the upper end of the sealing cylinder (63). The upper end of the lifting column (64) is provided with an axial bearing (65). When the telescopic cylinder (62) drives the sealing cylinder (63) to rise, the upper end face of the axial bearing (65) on the lifting column (64) abuts against the lower end face of the balancing heating mechanism (3). The inner wall of the circular discharge port (21) is provided with a spiral groove (211). When the centrifuge cylinder (2) rotates, the spiral groove (211) is used to transport the medium in the gap between the sealing cylinder (63) and the circular discharge port (21) upward to form a dynamic seal.

2. The closed-loop recycling and reuse device for polyester waste according to claim 1, characterized in that, The balanced heating mechanism (3) includes a mounting frame (31), on which a heating shell (32) is connected, and a heating source (33) is provided inside the heating shell (32); the output shaft (4) is connected to the mounting frame (31) by a spline or involute key.

3. The closed-loop recycling and reuse device for polyester waste according to claim 2, characterized in that, The heating shell (32) is provided with an outer isolation cover (321) on its lower end surface, and an inner isolation cover (641) is connected to the outer surface of the lifting column (64). The inner isolation cover (641) is arranged inside the outer isolation cover (321) to form a sliding connection.

4. The closed-loop recycling and reuse device for polyester waste according to claim 1, characterized in that, The upper end of the lifting frame (61) is coaxially connected to the upper guide cylinder (611), and the inner wall of the sealing cylinder (63) is slidably connected to the upper guide cylinder (611).

5. The closed-loop recycling and reuse device for polyester waste according to claim 1, characterized in that, The lower end face of the balanced heating mechanism (3) is provided with an annular guide groove (34), and the upper outer circumferential surface of the axial bearing (65) is slidably sleeved in the annular guide groove (34).

6. The closed-loop recycling and reuse device for polyester waste according to claim 1, characterized in that, The tank (1) is provided with a partition support cylinder (11), and the lower end of the outer wall of the centrifuge cylinder (2) is provided with an annular support plate (22). The partition support cylinder (11) can support the annular support plate (22).

7. The closed-loop recycling and reuse device for polyester waste according to claim 6, characterized in that, The annular support plate (22) has a downwardly extending drainage tube (23) on its outer periphery.

8. A closed-loop recycling and reuse method for polyester waste, based on the closed-loop recycling and reuse device for polyester waste according to any one of claims 1-7, characterized in that, include: S1: Start the lifting mechanism (6) until the clutch mechanism (5) at the upper end of the output shaft (4) engages with the input shaft (P1) of the external power source (P); S2: Start the external power source (P) and drive the centrifuge tube (2) to rotate through the input shaft (P1), clutch mechanism (5) and output shaft (4); S3: The material enters the centrifuge cylinder (2) for centrifugal separation; S4: After centrifugal separation is completed, the external power source (P) is stopped and the lifting mechanism (6) is driven to lower the sealing cylinder (63), open the circular discharge port (21), and allow solid impurities to fall; at the same time, the clutch mechanism (5) is separated from the input shaft (P1).

9. The closed-loop recycling and reuse method for polyester waste according to claim 8, characterized in that, In S3, the separated slurry enters the area between the centrifuge tube (2) and the tank (1), and the slurry flows out continuously from the discharge pipe.

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