An improved structure of a water circulation system of a polyester production pelletizer

Abstract

This utility model discloses a structural improvement device for the water circulation system of a polyester production pelletizer, belonging to the technical field of polyester production equipment. It includes a water circulation pipeline, a self-cleaning filter, an automatic switching valve, a secondary cooling device, and a control system. The water circulation pipeline is arranged in a ring. The self-cleaning filter is located at the upper part of the water circulation pipeline, the automatic switching valve is installed downstream of the self-cleaning filter, and the secondary cooling device is installed downstream of the automatic switching valve. The control system is connected to the self-cleaning filter, the automatic switching valve, and the secondary cooling device. This invention solves the technical problems of low operational flexibility and poor pre-dehydration effect in ethylene glycol pre-dehydration towers, and addresses the technical problems of poor water resource utilization and unstable system operation in current pelletizer water circulation systems. It is mainly applied to the water circulation utilization of pelletizers.

Description

Technical Field

[0001] This utility model belongs to the technical field of polyester production equipment, specifically relating to a structural improvement device for the water circulation system of a polyester pelletizer. Background Technology

[0002] With the development of water circulation systems for polyester pellet mills, various water circulation systems have been widely used. However, these systems still have some problems in actual use. For example, the water circulation systems for pellet mills on the market usually adopt traditional filtration and cooling methods, which have low water circulation efficiency. When facing high-volume production, it is difficult to achieve efficient water resource utilization, which leads to water waste and unstable system operation in some scenarios.

[0003] To improve performance, some manufacturers have tried to increase water circulation efficiency by adding multi-stage filtration devices. However, such improvements often face problems such as inconvenient switching of filtration devices and large fluctuations in system pressure, resulting in poor overall system stability and high maintenance costs.

[0004] Patent publication number (CN108837592B) discloses a pelletizing water filling device and pelletizing system, published on November 20, 2018. This patent adopts a dual filter switching structure, which achieves filter switching by setting multiple valves. Although this structure can provide a certain degree of filtration effect, the system pressure fluctuates greatly during valve switching, which can easily lead to unstable operation of the pelletizer. In addition, this design relies on manual or semi-automatic switching, which cannot meet the application requirements of modern industry for fully automated and real-time response scenarios.

[0005] A high-volume pelletizing system particle-water separation device, disclosed in patent publication number (CN117001881B) on November 7, 2023, uses a filtration mechanism and a water flow guiding mechanism to achieve particle-water separation by guiding the water flow direction. Although this design can achieve basic particle-water separation, its filtration mechanism is prone to trapping particles, resulting in low dewatering efficiency. At the same time, the design of the water flow guiding mechanism is relatively complex, and its maintenance cost is high. It is not suitable for large-scale industrial production scenarios that require efficient and low-cost operation. Therefore, it is difficult to meet the current industrial field's demand for a new type of pelletizer water circulation system with high efficiency and high degree of automation. Utility Model Content

[0006] Purpose of the utility model: The purpose of this utility model is to provide a structural improvement device for the water circulation system of a polyester production pelletizer, so as to solve the technical problems of poor water resource utilization and unstable system operation of the current pelletizer water circulation system.

[0007] The above-mentioned technical objective of this utility model is achieved through the following technical solution: a structural improvement device for the water circulation system of a polyester production pelletizer, comprising a water circulation pipe, a self-cleaning filter, an automatic switching valve, a secondary cooling device, and a control system. The water circulation pipe is arranged in a ring, the self-cleaning filter is installed at the upper part of the water circulation pipe, the automatic switching valve is installed downstream of the self-cleaning filter, the secondary cooling device is installed downstream of the automatic switching valve, and the control system is connected to the self-cleaning filter, the automatic switching valve, and the secondary cooling device.

[0008] Furthermore: The self-cleaning filter includes a filter cartridge, a rotating brush, and a drive motor. The filter cartridge is cylindrical and contains a filter screen. The rotating brush is installed inside the filter cartridge and is connected to the drive motor. The drive motor is fixed on the outer wall of the filter cartridge. The rotation direction of the rotating brush is opposite to the water flow direction in the water circulation pipe. The bottom of the filter cartridge is provided with a drain port, which is connected to the waste treatment system through a drain pipe.

[0009] Furthermore: The automatic switching valve includes a main valve body, a switching valve core, and a drive cylinder. The main valve body is cylindrical and has two mutually perpendicular channels inside. The switching valve core is installed inside the main valve body. The drive cylinder is connected to the switching valve core and is controlled by the control system. The switching valve core has two working positions, which switch the two channels of the main valve body to different water flow paths respectively. Pressure sensors are installed upstream and downstream of the automatic switching valve, and the pressure sensors are connected to the control system.

[0010] Furthermore: the secondary cooling device includes a first cooler and a second cooler. The first cooler is installed downstream of the automatic switching valve, and the second cooler is installed downstream of the first cooler. Both the first and second coolers are plate heat exchangers. The refrigerant inlet and outlet of the plate heat exchanger are connected to the refrigerant supply system, and the cooling water inlet and outlet of the plate heat exchanger are connected to the water circulation pipe. A bypass pipe is provided between the first and second coolers, and a regulating valve is provided on the bypass pipe. The regulating valve is controlled by the control system.

[0011] Furthermore: The control system includes a control box, a processor, input / output modules, and a display screen. The control box is installed in the control room of the pelletizer. The processor is connected to the input / output modules, which are connected to the self-cleaning filter, the automatic switching valve, the secondary cooling device, and the pressure sensor. The display screen is installed at the front of the control box and is used to display the system's operating status and parameters.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] 1. The self-cleaning filter uses a rotating brush to clean the filter screen in the opposite direction, effectively preventing particulate matter from remaining on the filter screen, improving filtration efficiency, reducing maintenance frequency, and lowering maintenance costs;

[0014] 2. The automatic switching valve intelligently switches the water flow path based on feedback from the control system and pressure sensor, ensuring stable operation of the system under different production loads and improving the system's adaptability and stability.

[0015] 3. The secondary cooling device achieves efficient cooling and energy saving through the design of dual-stage cooling and bypass pipelines, ensuring that the water temperature is within the set range, thereby improving the production efficiency and product quality of the pelletizer. Attached Figure Description

[0016] Figure 1 This is a structural diagram of the utility model;

[0017] Figure 2 This is a structural diagram of the self-cleaning filter of this utility model;

[0018] Figure 3 This is a structural diagram of the automatic switching valve of this utility model.

[0019] The attached diagram is labeled as follows: 1. Water circulation pipe; 2. Self-cleaning filter; 3. Automatic switching valve; 4. Secondary cooling device; 5. Control system; 6. Filter cartridge; 7. Rotary brush; 8. Drive motor; 9. Filter screen; 10. Drain outlet; 11. Drain pipe; 12. Main valve body; 13. Switching valve core; 14. Drive cylinder; 15. Pressure sensor; 16. First cooler; 17. Second cooler; 18. Bypass pipe; 19. Regulating valve; 20. Refrigerant inlet; 21. Refrigerant outlet; 22. Cooling water inlet; 23. Cooling water outlet; 24. Refrigerant supply system; 25. Control box; 26. Processor; 27. Input / output module; 28. Display screen; 29. ​​Electric valve; 30. First position; 31. Second position. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0021] In the description of this utility model, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used solely for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] Example 1:

[0023] In one technical solution of this utility model, such as Figure 1 As shown, this utility model provides a structural improvement device for the water circulation system of a polyester production pelletizer, including a water circulation pipe 1, a self-cleaning filter 2, an automatic switching valve 3, a secondary cooling device 4, and a control system 5. The water circulation pipe 1 is arranged in a ring, the self-cleaning filter 2 is located at the upper part of the water circulation pipe 1, the automatic switching valve 3 is installed downstream of the self-cleaning filter 2, the secondary cooling device 4 is installed downstream of the automatic switching valve 3, and the control system 5 is connected to the self-cleaning filter 2, the automatic switching valve 3, and the secondary cooling device 4.

[0024] The self-cleaning filter 2 includes a filter cartridge 6, a rotating brush 7, and a drive motor 8. The filter cartridge 6 is cylindrical and contains a filter screen 9. The rotating brush 7 is installed inside the filter cartridge 6 and is connected to the drive motor 8, which is fixed to the outer wall of the filter cartridge 6. The rotation direction of the rotating brush 7 is opposite to the water flow direction in the water circulation pipe 1. The filter screen 9 filters particulate matter in the water. The bottom of the filter cartridge 6 has a drain port 10, which is connected to the waste treatment system through a drain pipe 11. The drain pipe 11 is equipped with an electric valve 29, which is controlled by the control system 5. Specifically, the bristles of the rotating brush 7 are made of wear-resistant material, with a bristle length of 10 mm. The rotation speed of the rotating brush 7 is 450 rpm, and the diameter of the drain port 10 is 40 mm.

[0025] The automatic switching valve 3 includes a main valve body 12, a switching valve core 13, and a drive cylinder 14. The main valve body 12 is cylindrical and has two mutually perpendicular channels inside. The switching valve core 13 is installed inside the main valve body 12, and the drive cylinder 14 is connected to the switching valve core 13 and controlled by the control system 5. The switching valve core 13 has two working positions: a first position 30 and a second position 31. The first position 30 connects the two channels of the main valve body 12 to the first cooler 16 and the second cooler 17, respectively, while the second position 31 connects both channels of the main valve body 12 to the first cooler 16. Pressure sensors 15 are installed upstream and downstream of the automatic switching valve 3, and the pressure sensors 15 are connected to the control system 5. Specifically, the drive cylinder 14 has a stroke of 250 mm and a thrust of 800 N.

[0026] The secondary cooling device 4 includes a first cooler 16 and a second cooler 17. The first cooler 16 is installed downstream of the automatic switching valve 3, and the second cooler 17 is installed downstream of the first cooler 16. Both the first cooler 16 and the second cooler 17 are plate heat exchangers. The refrigerant inlet 20 and outlet 21 of the plate heat exchangers are connected to the refrigerant supply system 24, which supplies refrigerant through pipelines. The cooling water inlet 22 and outlet 23 of the plate heat exchangers are connected to the water circulation pipeline 1. A bypass pipeline 18 is provided between the first cooler 16 and the second cooler 17, and a regulating valve 19 is installed on the bypass pipeline 18. The regulating valve 19 is controlled by the control system 5. Specifically, the heat exchange plates of the plate heat exchangers are made of stainless steel, with a thickness of 1 mm and an area of ​​0.75 m². 2 The diameter of the bypass pipe 18 is 75mm, and the adjustment range of the regulating valve 19 is 0% to 100%.

[0027] The control system 5 includes a control box 25, a processor 26, an input / output module 27, and a display screen 28. The control box 25 is installed inside the pelletizer's control room. The processor 26 is connected to the input / output module 27, which is connected to the self-cleaning filter 2, the automatic switching valve 3, the secondary cooling device 4, and the pressure sensor 15. The display screen 28 is installed at the front of the control box 25 and is used to display the system's operating status and parameters. Specifically, the processor 26 is an embedded microcontroller, the input / output module 27 includes digital input / output modules and analog input / output modules, the display screen 28 is a color LCD screen with a resolution of no less than 800x480 pixels, and the control box 25 has a dustproof and waterproof design with an IP65 protection rating.

[0028] The water circulation path diagram further illustrates the system's operating principle. Water from the pelletizer's water circulation system enters the self-cleaning filter 2 through water circulation pipe 1. The filter screen 9 inside the self-cleaning filter 2 filters particulate matter from the water. A rotating brush 7, driven by a drive motor 8, rotates in the opposite direction to scrub the filter screen 9, preventing particulate matter from accumulating on it. The drain port 10 is opened periodically, and particulate matter on the filter screen 9 is discharged to the waste treatment system through the drain pipe 11. The filtered water then passes through an automatic switching valve 3. The automatic switching valve 3 switches the water flow path based on preset parameters in the control system 5 and feedback from the pressure sensor 15. During high-volume production, the automatic switching valve 3 switches the water flow path to the first cooler 16 and the second cooler 17, achieving dual-stage cooling and ensuring the water temperature remains within the set range. During low-volume production, the automatic switching valve 3 switches the water flow path to the first cooler 16, bypassing the second cooler 17 through the bypass pipe 18, reducing energy consumption. The first cooler 16 and the second cooler 17 employ plate heat exchangers and are cooled by refrigerant supplied by the refrigerant supply system 24. The cooled water then re-enters the water circulation pipe 1, completing one cycle. The control system 5 intelligently controls the entire system through the processor 26 in the control box 25, receives and sends signals through the input / output module 27, and displays the system's operating status and parameters through the display screen 28, achieving comprehensive monitoring and optimization of the water circulation system.

[0029] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of the present utility model, and these improvements should also be considered within the protection scope of the present utility model.

Claims

1. A structural improvement device for the water circulation system of a polyester production pelletizer, comprising a water circulation pipe (1), a self-cleaning filter (2), an automatic switching valve (3), a secondary cooling device (4), and a control system (5). The water circulation pipe (1) is arranged in a ring. The self-cleaning filter (2) is located at the upper part of the water circulation pipe (1). The automatic switching valve (3) is installed downstream of the self-cleaning filter (2). The secondary cooling device (4) is installed downstream of the automatic switching valve (3). The control system (5) is connected to the self-cleaning filter (2), the automatic switching valve (3), and the secondary cooling device (4).

2. The structural improvement device of a water circulation system of a pelletizer for polyester production according to claim 1, characterized in that, The self-cleaning filter (2) includes a filter cylinder (6), a rotating brush (7) and a drive motor (8). The filter cylinder (6) is cylindrical and contains a filter screen (9). The filter screen (9) filters particulate matter in the water. The rotating brush (7) is installed inside the filter cylinder (6) and connected to the drive motor (8). The drive motor (8) is fixed on the outer wall of the filter cylinder (6). The rotation direction of the rotating brush (7) is opposite to the water flow direction in the water circulation pipe (1). The bottom of the filter cylinder (6) is provided with a drain port (10). The drain port (10) is connected to the waste treatment system through a drain pipe (11). An electric valve (29) is installed on the sewage pipe (11), and the electric valve (29) is controlled by the control system (5).

3. The structural improvement device for the water circulation system of a polyester pelletizer according to claim 2, characterized in that, The automatic switching valve (3) includes a main valve body (12), a switching valve core (13), and a drive cylinder (14). The main valve body (12) is cylindrical and has two mutually perpendicular channels inside. The switching valve core (13) is installed inside the main valve body (12). The drive cylinder (14) is connected to the switching valve core (13). The drive cylinder (14) is controlled by the control system (5). The switching valve core (13) has two working positions, namely the first position (30) and the second position (31), which switch the two channels of the main valve body (12) to different water flow paths. The first position (30) connects the two channels of the main valve body (12) to the first cooler (16) and the second cooler (17) respectively. The second position (31) connects the two channels of the main valve body (12) to the first cooler (16). Pressure sensors (15) are provided upstream and downstream of the automatic switching valve (3). The pressure sensors (15) are connected to the control system (5).

4. The construction improvement device of a water circulation system of a pelletizer for polyester production according to claim 3, characterized in that, The secondary cooling device (4) includes a first cooler (16) and a second cooler (17). The first cooler (16) is installed downstream of the automatic switching valve (3), and the second cooler (17) is installed downstream of the first cooler (16). Both the first cooler (16) and the second cooler (17) are plate heat exchangers. The refrigerant inlet (20) and outlet (21) of the plate heat exchanger are connected to the refrigerant supply system (24) respectively. The cooling water inlet (22) and cooling water outlet (23) of the plate heat exchanger are connected to the water circulation pipe (1) respectively. A bypass pipe (18) is provided between the first cooler (16) and the second cooler (17). A regulating valve (19) is provided on the bypass pipe (18). The regulating valve (19) is controlled by the control system (5).

5. The construction improvement device of a water circulation system of a pelletizer for polyester production according to claim 4, characterized in that, The control system (5) includes a control box (25), a processor (26), an input / output module (27), and a display screen (28). The control box (25) is installed in the control room of the pelletizer. The processor (26) is connected to the input / output module (27). The input / output module (27) is connected to the self-cleaning filter (2), the automatic switching valve (3), the secondary cooling device (4), and the pressure sensor (15). The display screen (28) is installed at the front of the control box (25) and is used to display the working status and parameters of the system.

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