Polyester regenerated raw material conveying system

Abstract

The utility model relates to a polyester regenerated raw material conveying system. A plurality of problems exist in processing and conveying of traditional polyester regenerated cloth, for example, energy consumption for manufacturing bubble materials is high, water content is high, follow-up procedures are affected, materials are prone to being blocked during conveying, and valve sealing is poor. The system can solve the problems, waste heat or steam is used for heating rags, and a large-dip-angle belt conveyor is used for feeding, so that energy consumption is reduced; the moisture content is reduced by a drying roller, and the stability is improved by a compacting device; and material blockage is avoided through double-helix feeding. The system comprises a metering scale, a crusher and the like, the rotary internal screw dryer has specific parameters, the compaction device is special in structure, the vertical screw conveyor vertically feeds materials downwards, the outlet end of the vertical screw conveyor is provided with a pushing device, and a nitrogen inlet is formed between the gate valve and the reaction kettle. The system has obvious advantages in the aspects of energy consumption, stability, material blocking, waste heat utilization and the like, and the overall performance can be improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of polyester regeneration equipment, in particular to a polyester regeneration raw material conveying system. Background Art

[0002] In the field of polyester recycling, fabric processing and transportation play a crucial role in the entire production process. The operation of this link is directly related to several key aspects of polyester recycling, such as production efficiency, cost control, and product quality.

[0003] Traditional fabric processing involves forming the fabric into foam, which is then transported to a large silo on the top of the workshop using pneumatic conveying. The foam is produced using a semi-plasticized, water-added granulation process. However, this traditional processing and conveying method presents a number of challenges.

[0004] First, energy consumption is a prominent issue. The semi-plasticized water-adding granulation process used to produce foam materials consumes a significant amount of energy. Against the backdrop of rising energy costs and the global push for energy conservation and emission reduction, this energy-intensive process not only significantly increases production costs but also runs counter to current sustainable development concepts. This means companies face higher energy costs and greater environmental pressure.

[0005] Secondly, the high moisture content of the foam material creates numerous challenges for downstream processes. A high moisture content can alter the physical and chemical properties of the material, negatively impacting the operational load of downstream processes. In actual production, this can cause downstream equipment to operate beyond its normal design parameters, challenging its operational stability. For example, this can cause fluctuations in operating parameters such as temperature and pressure, impacting product quality stability. This can lead to uneven product quality and substandard performance, increasing uncertainty and risk in the production process.

[0006] Third, existing conveying processes and equipment themselves have flaws. For example, when using a screw conveyor to transport materials into a reactor, the materials become damp due to the ethylene glycol vapor before the reactor exits. Wet materials easily adhere to the inner wall of the conveying pipe, and over time and with the continuous accumulation of materials, they can easily cause blockage. Once a blockage occurs, the entire production process is forced to be interrupted, and production efficiency is greatly reduced. To resume production, companies need to invest a lot of manpower and time to clear the blocked materials, which undoubtedly increases the labor cost of production. Moreover, frequent blockages can damage the conveying equipment and shorten its service life, further increasing the company's equipment maintenance and replacement costs.

[0007] Fourthly, the ball valve and gate valve beneath the vertical screw conveyor also present issues. During actual operation, material often becomes stuck in the pipe wall. This material stagnation prevents the valve from fully closing, preventing an effective seal. Incomplete valve sealing compromises the integrity of the entire conveying system, potentially allowing material to leak from the valve. This not only results in material waste but also potentially pollutes the surrounding environment. Furthermore, leaked material can enter other parts of the equipment, impacting its normal operation and further disrupting production.

[0008] In summary, the existing technical solutions have considerable problems in many aspects such as energy consumption, production costs, production stability and equipment operation. These problems have seriously restricted the development of the polyester recycling field. Therefore, there is an urgent need for a more optimized solution to improve the current fabric processing and transportation conditions. Utility Model Content

[0009] In view of this, the present invention aims to propose a polyester recycled raw material conveying system. This system overcomes the shortcomings of the existing polyester recycled fabric processing and conveying process, and provides a system with reasonable design and high efficiency. The system can solve the problem of high energy consumption in the process of making foam materials, and heat the scraps of fabric by utilizing the waste heat or steam generated by other processes, thereby reducing energy consumption and reducing production costs; in response to the high energy consumption problem in the conveying process of the pneumatic conveying device, a large-angle belt conveyor is used to directly convey the pre-pressed scraps of fabric to the upper buffer bin of the double-screw conveyor, thereby reducing the conveying energy consumption; to solve the problem that the moisture content of the foam material is high and affects the operating load of the subsequent process, the fabric is dried with the help of a drying drum with an inner spiral to reduce the moisture content and reduce the burden on the subsequent process; and it can deal with the problem of material blockage in the existing conveying process and equipment, and directly adopt double-screw feeding to push the material directly vertically into the reactor to avoid material blockage, thereby improving production efficiency.

[0010] In order to achieve the above-mentioned purpose, the technical solution of the utility model is achieved as follows:

[0011] A polyester recycled raw material conveying system includes a weighing scale, a belt conveyor, a crusher, a rotary inner spiral dryer, a compacting device, a large-angle belt conveyor, a horizontal spiral feeder, a vertical spiral conveyor, a ball valve, a gate valve, and a depolymerization reactor. The weighing scale is arranged at the front end of the belt conveyor, and the rear end of the belt conveyor is connected to the crusher feed port. After the rags and waste clothes are processed in the previous sorting process, the fabrics with a polyester content greater than 90% are grabbed and weighed by the weighing scale, and then sent to the crusher via the belt conveyor and crushed into rags with a size of less than 3×3 cm. The crusher discharge port is connected to the feed port of the rotary inner spiral dryer. The rotary inner spiral dryer dries the fabric while conveying the fabric forward. The rotary inner spiral dryer discharge port is connected to the feed port of the compacting device. After drying treatment by the drying drum, the moisture content of the rags is further reduced to 1%. The following has good thermoplasticity. The discharge port of the compacting device is connected to the front end of the large-angle belt conveyor, and the rear end of the large-angle belt conveyor is connected to the feed port of the horizontal screw feeder. The discharge port of the horizontal screw feeder is connected to the feed port of the vertical screw conveyor, and the feed port of the vertical screw conveyor is connected to the ball valve, the ball valve is connected to the gate valve, and the gate valve is connected to the feed port of the depolymerization reactor.

[0012] In a structure that can optimize the above-mentioned solution, the drying drum in the rotary inner spiral dryer has a diameter of 1000 mm, a length of 4000 mm, a rotation speed of 10 r / min, and a temperature in the drying drum controlled at 160°C.

[0013] Furthermore, the compacting device is provided with a plate chain with an angle. The compacting device performs preliminary compression on the heated and dried scraps of fabric, and the compression device mainly uses a stainless steel plate chain with a certain angle to gradually compress the fabric.

[0014] In a structure that can optimize the above solution, a sealed heating space is provided outside the compacting device. Since the fabric has good thermoplasticity, the rebound rate after compression is greatly reduced, thereby achieving the effect of increasing the packing density.

[0015] One structure that optimizes the aforementioned solution also includes a buffer chamber. The front end of a steeply angled belt conveyor is connected to the buffer chamber inlet, and the buffer chamber outlet is connected to the feed inlet of a horizontal screw feeder. The steeply angled belt conveyor directly transports the pre-pressed rags to the upper buffer chamber of the twin-screw conveyor. The twin-screw feeder then pushes the materials vertically into the reactor. The conveying process is fully enclosed, and the reaction temperature required is 210°C.

[0016] Furthermore, the vertical screw conveyor conveys the raw materials vertically downward. This facilitates material transport and gravity utilization, leveraging gravity to facilitate smoother material transport. Its gravity component is in the same direction as the screw's propulsion force, reducing energy loss and helping to form a stable material flow, reducing the risk of blockage and ensuring system continuity and stability. Furthermore, it adapts to system layout and process requirements. From a spatial layout perspective, it optimizes the plant's spatial structure, making the system more compact and facilitating efficient connection with upstream and downstream equipment. From a process perspective, it meets the feed requirements of the depolymerization reactor, ensuring accurate and uniform material entry into the reactor, and improving the efficiency and quality of the depolymerization reaction.

[0017] In a configuration that optimizes the aforementioned solution, a nitrogen inlet is located between the gate valve and the depolymerization reactor, with the nitrogen inlet flowing downward from top to bottom. Below the gate valve, 0.1 bar of nitrogen gas displaces oxygen from the raw materials, ensuring a safe reaction process.

[0018] In a structure that can optimize the aforementioned solution, the outlet end of the vertical screw conveyor is provided with a pushing device, comprising a hollow screw shaft, a spring, a housing, a slider, a push rod, and a frame. One end of the push rod is inserted into the hollow screw shaft, the slider is mounted on the push rod, the frame is hinged to the push rod and the slider, respectively, the spring is mounted on the push rod, one end of the spring is connected to the slider, and the other end of the spring is in contact with the hollow screw shaft, and the hollow screw shaft is disposed within the housing. The frame, push rod, and slider are hingedly connected, and the entire frame is rotatable. The structure is similar to that of an umbrella frame. After the push rod extends out of the hollow screw shaft, the spring, which is already compressed, pushes down the slider, and the frame opens, thereby pushing material that has failed to fall into the reactor from the pipeline into the reactor. When the push rod is retracted, the frame is squeezed by the inner wall of the housing, compressing the spring and closing the frame, thereby ensuring the normal operation of the vertical screw conveyor. After the material is pushed through this device, the accumulation of material at the valve is greatly reduced, which can improve the sealing performance of the valve.

[0019] Furthermore, the diameter of the skeleton when opened is larger than the inner diameter of the outer shell. This structure, on the one hand, ensures effective material delivery by expanding the delivery range and increasing the contact area with the material, allowing the material to be more thoroughly delivered to the reactor, improving delivery efficiency, while also increasing the delivery force and overcoming material resistance such as friction and adhesion. On the other hand, it prevents material residue by thoroughly cleaning the pipe wall, preventing material from adhering to the inner wall of the outer shell and affecting delivery or even causing blockage, while also reducing material accumulation in the valve, improving valve sealing, and reducing the risk of valve failure and leakage.

[0020] Compared with the existing technology, the polyester recycled raw material conveying system described in the present invention has the following advantages:

[0021] First, to reduce energy consumption, waste heat or steam from other processes is used to heat the shredded fabric, which is then dried using a drying drum with an internal spiral. This method eliminates the granulation step, reduces energy consumption, and achieves energy recycling, further reducing costs. Furthermore, a high-angle belt conveyor is used to deliver the pre-compressed shredded fabric to the upper buffer bin of the double-screw conveyor. Its power is lower than that of a pneumatic conveying system, achieving the goals of reducing conveying energy consumption and saving costs. Second, to improve production stability and prevent blockages, a compression device is used to initially compress the heated and dried shredded fabric. This solves the problem of high moisture content in traditional foam materials, which affects the operating load of subsequent processes, ensuring stable production operations. Furthermore, direct double-screw feeding and a new pusher device push the material vertically into the reactor to prevent the material from becoming moist due to the influence of ethylene glycol vapor and causing blockages, improving production efficiency and reducing maintenance difficulty and costs.

[0022] In summary, this solution demonstrates significant advantages in reducing energy consumption, improving production stability, reducing transportation energy consumption, avoiding material blockage, and comprehensively utilizing waste heat steam, and can effectively improve the overall performance of the polyester recycled raw material transportation system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which constitute part of the present invention, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0024] Figure 1 This is a schematic structural diagram of the polyester recycled raw material conveying system of the present invention;

[0025] Figure 2 This is a schematic structural diagram of the internal pushing device of the vertical screw conveyor of the present utility model.

[0026] Description of reference numerals:

[0027] 1. Weighing scale, 2. Raw materials, 3. Belt conveyor, 4. Crusher, 5. Rotary inner screw dryer, 6. Compacting device, 7. High-angle belt conveyor, 8. Horizontal screw feeder, 9. Vertical screw conveyor, 10. Ball valve, 11. Gate valve, 12. Depolymerization reactor, 13. Hollow screw shaft, 14. Spring, 15. Housing, 16. Slider, 17. Push rod, 18. Frame, 19. Buffer bin. DETAILED DESCRIPTION

[0028] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features therein can be combined with each other.

[0029] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0030] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0031] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0032] The polyester recycled raw material conveying system is mainly composed of a weighing scale 1, a belt conveyor 3, a crusher 4, a rotary inner screw dryer 5, a compacting device 6, a large-angle belt conveyor 7, a horizontal screw feeder 8, a vertical screw conveyor 9, a ball valve 10, a gate valve 11, a depolymerization reactor 12 and other components.

[0033] Weighing scale 1 is located at the front end of belt conveyor 3, the rear end of which connects to the feed port of crusher 4. Fabric with a polyester content greater than 90% after the previous sorting process is picked up and weighed by the weighing scale before being conveyed via the belt conveyor to the crusher, where it is broken into shredded fabric pieces within a size of 3 x 3 cm. The discharge port of crusher 4 is connected to the feed port of rotary internal spiral dryer 5. The drying drum in rotary internal spiral dryer 5 has a diameter of 1000 mm, a length of 4000 mm, and a rotation speed of 10 rpm. Its internal temperature is controlled at 160°C. As the fabric is dried and conveyed forward, the moisture content of the shredded fabric is further reduced to below 1%, while also maintaining good thermoplastic properties.

[0034] The discharge port of the rotary inner spiral dryer 5 is connected to the feed port of the compacting device 6. The compacting device 6 is provided with an angled plate chain inside and a sealed heating space outside. The stainless steel plate chain with a certain angle is used to gradually compress the fabric. Due to the good thermoplasticity of the fabric, the rebound rate after compression is greatly reduced, which can increase the bulk density. The discharge port of the compacting device 6 is connected to the front end of the high-angle belt conveyor 7. In an optimized structure, the front end of the high-angle belt conveyor 7 can be connected to the feed port of the buffer bin 19 first, and the outlet of the buffer bin 19 is then connected to the feed port of the horizontal screw feeder 8. The rear end of the high-angle belt conveyor 7 is connected to the feed port of the horizontal screw feeder 8. The discharge port of the horizontal screw feeder 8 is connected to the feed port of the vertical screw conveyor 9. The vertical screw conveyor 9 conveys the raw materials vertically downward and its feed port is connected to the ball valve 10. The ball valve 10 is connected to the gate valve 11, and the gate valve 11 is connected to the feed port of the depolymerization reactor 12.

[0035] A nitrogen inlet is provided between the gate valve 11 and the depolymerization reactor 12. The inlet direction is from top to bottom. There is 0.1 bar nitrogen below the gate valve to replace the oxygen contained in the raw materials from bottom to top to ensure the safety of the reaction. The outlet of the vertical screw conveyor 9 is equipped with a pushing device, which includes a hollow screw shaft 13, a spring 14, a housing 15, a slider 16, a push rod 17, and a skeleton 18. One end of the push rod 17 is inserted into the hollow screw shaft 13, and the slider 16 is mounted on the push rod 17. The skeleton 18 is hinged to the push rod 17 and the slider 16 respectively. The spring 14 is mounted on the push rod 17, one end of the spring 14 is connected to the slider 16, and the other end is in contact with the hollow screw shaft 13. The hollow screw shaft 13 is set in the housing 15. When the skeleton is opened, the diameter of the skeleton is larger than the inner diameter of the housing 15. After the push rod extends out of the hollow screw shaft, the spring pushes down the slider to open the skeleton, pushing the material that has not fallen into the reactor into the reactor. When the push rod is retracted, the skeleton is squeezed by the inner wall of the housing, compressing the spring and closing the skeleton, thereby ensuring the normal operation of the vertical screw conveyor and reducing material accumulation at the valve to improve the valve sealing. The entire conveying process is fully enclosed, and the required reaction temperature is 210°C.

[0036] Working principle:

[0037] After rags and used clothing are sorted through the previous sorting process, fabrics with a polyester content greater than 90% are used as raw material 2. They are first grabbed and weighed by a weighing scale 1 located at the front end of a belt conveyor 3, and then conveyed to a crusher 4 via the belt conveyor 3 to be broken into rags within a size of 3×3cm. The discharge port of the crusher 4 is connected to the feed port of a rotary internal spiral dryer 5. The drying drum in the rotary internal spiral dryer 5 has a diameter of 1000mm, a length of 4000mm, a rotation speed of 10r / min, and a temperature controlled at 160°C. The fabric is conveyed forward while drying, reducing the moisture content of the rags to 1%. The cloth comes out of the compacting device 6 and is connected to the front end of the large-angle belt conveyor 7. If there is a buffer bin 19, the large-angle belt conveyor 7 first sends the cloth to the buffer bin 19 and then connects its outlet to the feed port of the horizontal screw feeder 8. If not, the rear end of the large-angle belt conveyor 7 is directly connected to the feed port of the horizontal screw feeder 8. The discharge port of the horizontal screw feeder 8 is connected to the feed port of the vertical screw conveyor 9. The vertical screw conveyor 9 transports the raw materials vertically downward and is connected to the feed port of the depolymerization reactor 12 through the ball valve 10 and the gate valve 11. The direct double-helix feeding prevents the material from being affected by the ethylene glycol vapor and becoming wet and blocked. There is a nitrogen inlet between the gate valve 11 and the depolymerization reactor 12. The air is fed from top to bottom and there is 0.1 bar below the gate valve. Nitrogen replaces oxygen to ensure reaction safety. The pushing device at the outlet end of the vertical screw conveyor 9 is composed of a hollow screw shaft 13, a spring 14, a shell 15, a slider 16, a push rod 17, and a skeleton 18. When the push rod 17 is extended, the skeleton 18 opens to push the unfallen material. When it is retracted, the skeleton 18 is retracted to reduce valve material accumulation and improve sealing. The entire process uses waste heat or steam to heat and dry the cloth with a drying drum, eliminating the granulation step, reducing energy consumption and recycling energy. The large-angle belt conveyor 7 reduces transportation energy consumption. The compacting device 6 solves the problem of high moisture content of traditional foam materials affecting subsequent processes, avoids blockage, improves production efficiency, reduces maintenance difficulty and cost, and improves the overall performance of the polyester recycled raw material transportation system.

[0038] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A polyester recycled raw material conveying system, characterized by: Weighing scale (1), belt conveyor (3), crusher (4), rotary inner spiral dryer (5), compacting device (6), large-angle belt conveyor (7), horizontal spiral feeder (8), vertical spiral conveyor (9), ball valve (10), gate valve (11), depolymerization reactor (12), weighing scale (1) is set at the front end of belt conveyor (3), the rear end of belt conveyor (3) is connected to the feed port of crusher (4), and the discharge port of crusher (4) is connected to the feed port of rotary inner spiral dryer (5). The discharge port of the rotary inner screw dryer (5) is connected to the feed port of the compacting device (6), the discharge port of the compacting device (6) is connected to the front end of the large-angle belt conveyor (7), the rear end of the large-angle belt conveyor (7) is connected to the feed port of the horizontal screw feeder (8), the discharge port of the horizontal screw feeder (8) is connected to the feed port of the vertical screw conveyor (9), the feed port of the vertical screw conveyor (9) is connected to the ball valve (10), the ball valve (10) is connected to the gate valve (11), and the gate valve (11) is connected to the feed port of the depolymerization reactor (12).

2. The polyester recycled raw material conveying system according to claim 1, characterized in that: The drying drum in the rotary inner spiral dryer (5) has a diameter of 1000 mm and a length of 4000 mm.

3. The polyester recycled raw material conveying system according to claim 1, characterized in that: A plate chain with an angle is provided inside the compacting device (6).

4. The polyester recycled raw material conveying system according to claim 1, characterized in that: A sealed heating space is provided outside the compacting device (6).

5. The polyester recycled raw material conveying system according to claim 1, characterized in that: It also includes a buffer bin (19), the front end of the high-angle belt conveyor (7) is connected to the feed port of the buffer bin (19), and the outlet of the buffer bin (19) is connected to the feed port of the horizontal screw feeder (8).

6. The polyester recycled raw material conveying system according to claim 1, characterized in that: The vertical screw conveyor (9) conveys the raw materials vertically downward.

7. The polyester recycled raw material conveying system according to claim 1, characterized in that: A nitrogen inlet is provided between the plug valve (11) and the depolymerization reactor (12), and the nitrogen inlet direction is from top to bottom.

8. The polyester recycled raw material conveying system according to claim 1, characterized in that: The outlet end of the vertical screw conveyor (9) is provided with a pushing device, which includes a hollow screw shaft (13), a spring (14), a housing (15), a slider (16), a push rod (17), and a skeleton (18). One end of the push rod (17) is inserted into the hollow screw shaft (13), the slider (16) is sleeved on the push rod (17), the skeleton (18) is hinged to the push rod (17) and the slider (16), the spring (14) is sleeved on the push rod (17), one end of the spring (14) is connected to the slider (16), and the other end of the spring (14) is in contact with the hollow screw shaft (13), and the hollow screw shaft (13) is arranged in the housing (15).

9. The polyester recycled raw material conveying system according to claim 8, characterized in that: The diameter of the skeleton (18) when opened is larger than the inner diameter of the shell (15).

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