A heating and melting device for regenerating polyester chips

Abstract

This utility model discloses a heating and melting device for recycled polyester chips, belonging to the technical field of melting devices. It includes a barrel and a connected head, a filter plate and a filter screen mounted thereon, and a slot at the top of the head for accommodating the filter plate. Several springs are installed in an annular groove on the inner wall of the slot. A second sealing ring is provided on the annular plate on which the springs are fixed. The inclined surface on the outer ring of the annular plate cooperates with the inclined surface on the side wall of the filter plate to push the annular plate to compress the springs. The springs drive the second sealing ring to adhere to the side wall of the filter plate. This utility model provides a heating and melting device for recycled polyester chips that enables quick filter screen replacement, reliable sealing performance, and easy maintenance.

Description

Technical Field

[0001] This utility model relates to the field of melting device technology, and in particular to a heating and melting device for recycled polyester chips. Background Technology

[0002] Currently, the equipment used for heating and melting recycled polyester chips is usually a screw extruder. During operation, the dried recycled PET chips are fed into the extruder barrel from the hopper. Through the rotation of the screw and the action of the external heater of the barrel, they are conveyed, compressed, melted and finally extruded from the die head.

[0003] Recycled polyester chips inevitably contain various physical impurities, such as tiny metal shavings, sand, unmelted polymer particles, or other impurities. In order to ensure the quality of subsequent products, effective filtration must be carried out before melt extrusion. Traditional filtration devices are usually complex in structure, and changing the filter screen is cumbersome and requires a long downtime. This directly affects the continuity and overall efficiency of the production line. In addition, some simple plate filters have poor sealing performance.

[0004] Polyester melt has the characteristics of high temperature and high pressure at the die head. For replaceable filter components, such as filter plates, sealing between them and the equipment die head is a technical challenge. Traditional flat seals or simple O-ring seals are prone to aging and failure under high temperature and high pressure, leading to melt leakage. This not only causes waste of raw materials and environmental pollution, but also poses serious safety hazards. Utility Model Content

[0005] The purpose of this invention is to provide a heating and melting device for recycled polyester chips that enables quick filter replacement, provides reliable sealing performance, and is easy to maintain.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a heating and melting device for recycled polyester chips, comprising a barrel and a head connected thereto, and further comprising a filter plate and a filter screen disposed thereon, wherein the top of the head is provided with a slot for accommodating the filter plate.

[0007] A number of springs are installed in the annular groove provided on the inner wall of the slot. A second sealing ring is provided on the annular plate on which the springs are fixed. The inclined surface of the outer ring of the annular plate cooperates with the inclined surface of the side wall of the filter plate to push the annular plate to compress the springs.

[0008] The spring is used to drive the second sealing ring to adhere to the side wall of the filter plate.

[0009] As a further description of the above technical solution: the barrel includes, in sequence along the material extrusion direction, a feeding cylinder, at least one melting cylinder and a homogenizing cylinder, which are fixedly connected by several mounting bolts.

[0010] As a further description of the above technical solution: the number of melting cylinders is two.

[0011] As a further description of the above technical solution: a hopper is fixed at the top of the feeding cylinder, and two screws are provided in the inner cavity of the cylinder.

[0012] As a further description of the above technical solution: the outer ring of the melting cylinder is provided with a heater and a water-cooling jacket.

[0013] As a further description of the above technical solution: the connecting surfaces of the feeding cylinder, the melting cylinder, the homogenizing cylinder, and the die head are provided with a first sealing ring.

[0014] As a further description of the above technical solution: a plurality of fixing bolts provided on the machine head are threaded through the machine head and threadedly connected to the filter plate.

[0015] As a further description of the above technical solution: a handle is provided on the top of the filter plate.

[0016] In summary, due to the adoption of the above technical solution, the beneficial effects of this utility model are:

[0017] 1. The filter plate adopts a direct insertion type and is equipped with a handle. When the filter screen needs to be replaced, the operator only needs to loosen a few fixing bolts to quickly pull out the entire filter plate and replace it with a spare part. The whole process is simple and quick, which simplifies the operation process and minimizes the production interruption time caused by filter screen replacement, thereby improving the operating efficiency of the equipment.

[0018] 2. By utilizing the inclined surface fit between the annular plate and the filter plate, automatic elastic pre-tightening of the second sealing ring is achieved. This dynamically compensates for gaps caused by high-temperature thermal expansion or minor wear, maintaining effective sealing pressure at all times. Combined with the rigid locking of the external fixing bolts, this solves the problem of melt leakage that is prone to occur in traditional plate filters under high pressure, ensuring the cleanliness and safety of the production process. Attached Figure Description

[0019] Figure 1 A perspective view of the present invention is shown;

[0020] Figure 2 A cross-sectional view of the present invention is shown;

[0021] Figure 3 This utility model is shown Figure 2 Enlarged view of point A in the middle;

[0022] Figure 4 This utility model is shown Figure 2 Enlarged view of point B in the middle;

[0023] Figure 5 A perspective view of the screw of this utility model is shown.

[0024] Legend:

[0025] 10. Barrel; 11. Feeding cylinder; 12. Melting cylinder; 13. Homogenizing cylinder; 14. Mounting bolts;

[0026] 20. Hopper; 21. Screw; 22. Heater; 23. Water-cooled jacket; 24. First sealing ring;

[0027] 30. Machine head; 31. Filter plate; 32. Filter screen; 33. Handle; 34. Spring; 35. Annular plate; 36. Second sealing ring; 37. Fixing bolt. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0029] Please see Figures 1-5 This utility model provides a technical solution: a heating and melting device for recycled polyester chips, including a barrel 10, a working component disposed inside the barrel 10, and a head 30 connected to the end of the barrel 10.

[0030] In this embodiment, the barrel 10 adopts a segmented modular design, which facilitates processing, installation and maintenance. Specifically, the barrel 10 is composed of a feeding cylinder 11, two melting cylinders 12 and a homogenizing cylinder 13 connected sequentially along the material advance direction. The cylinders are fixedly connected by high-strength mounting bolts 14 to ensure the reliability and sealing of the connection under high pressure working environment.

[0031] To prevent leakage of molten polyester at the cylinder connection, a first sealing ring 24 that is resistant to high temperature and corrosion is provided between the contact flange surfaces of the feeding cylinder 11, the melting cylinder 12, the homogenizing cylinder 13 and the subsequent connecting die head 30. The first sealing ring 24 is preferably made of graphite composite gasket or copper gasket to adapt to the high temperature working environment of polyester melt.

[0032] The inner cavity of the barrel 10 is a double-hole channel. Two screws 21 are arranged in parallel inside the barrel 10. The two screws 21 are driven to rotate by a drive system (not shown) to convey, compress, shear, melt and homogenize the material. The drive system includes a main motor and a gearbox.

[0033] The main motor provides power to the entire device and is usually an AC or DC motor; the gearbox connects the main motor and the screw 21, reducing the high speed of the main motor while increasing the torque to provide sufficient force to push and shear the material.

[0034] A hopper 20 is fixedly connected to the top of the feeding cylinder 11. Recycled polyester chips that have been fully dried by an external crystallization and drying device are added into the feeding cylinder 11 through this hopper 20.

[0035] The two melting cylinders 12 are the areas where polyester chips are transformed from a solid state to a molten state. A heater 22, such as a resistance heating coil or an electromagnetic induction heater, is provided around the outer circumference of each melting cylinder 12 to provide the main heat for melting the material. At the same time, in order to accurately control the temperature of the melting cylinder 12 and prevent the polyester melt from degrading due to excessive shear heat, a water-cooled jacket 23 is also provided on the outside of the heater 22. By controlling the flow rate of cooling water entering the jacket, it can work in conjunction with the heater 22 to achieve precise control of the cylinder temperature.

[0036] The melting cylinder 12 is equipped with both a heater 22 and a water-cooled jacket 23, which can simultaneously achieve heating and cooling. This effectively prevents local overheating caused by the accumulation of shear heat from the screw, avoids polyester degradation, and thus ensures the stability of melt viscosity and the quality of the final product.

[0037] The homogenizing cylinder 13 is located after the melting cylinder 12. Its main function is to further stir and mix the polyester melt that has been completely melted but may have uneven temperature or viscosity, so as to ensure that the extruded melt has a high degree of uniformity.

[0038] The barrel 10 adopts a modular structure consisting of a feeding barrel 11, a melting barrel 12, and a homogenizing barrel 13 connected by bolts in sections. When a certain part of the barrel wears out due to long-term use, only that specific section needs to be replaced, without replacing the entire barrel, which reduces spare parts costs and maintenance costs.

[0039] The end of the homogenizing cylinder 13 is fixedly connected to the die head 30 by mounting bolts 14. The die head 30 is the final channel for the melt to leave the extruder.

[0040] The machine head 30 has a filter structure inside. Specifically, the top of the machine head 30 has a slot, and the filter plate 31 is designed to be inserted or pulled out vertically from the slot. In order to facilitate the operator to install and replace, the top of the filter plate 31 is provided with an easy-to-grip handle 33.

[0041] On the main body of the filter plate 31, a through hole is provided at a position corresponding to the main melt channel inside the die head 30. A filter screen 32 is installed in the through hole. The filter screen 32 is a combination of multiple layers of metal mesh with different mesh sizes, which is used to intercept impurity particles in the melt.

[0042] To solve the sealing problem between the filter plate 31 and the slot of the head 30 after insertion, an annular groove is formed on the inner wall of the slot. Several springs 34 are pre-installed in the annular groove. The outer ends of the springs 34 abut against the bottom of the annular groove, and the inner ends push against an annular plate 35. The outer sidewall of the annular plate 35 is designed as a slope. At the same time, a high-temperature resistant second sealing ring 36 is installed on the side of the annular plate 35 facing the filter plate 31. The sidewall of the filter plate 31 is also machined with a slope that matches the outer ring of the annular plate 35.

[0043] When the operator holds handle 33 and inserts filter plate 31 into the slot, the inclined surface of filter plate 31 will first contact the inclined surface of annular plate 35. As filter plate 31 continues to go deeper, the two inclined surfaces slide relative to each other. This sliding action will generate a lateral component force, pushing annular plate 35 into the depth of the annular groove, thereby compressing spring 34.

[0044] Once the filter plate 31 is fully installed, its inclined surface no longer exerts lateral thrust on the annular plate 35. The elastic force of the compressed spring 34 will push the annular plate 35 back, causing the annular plate 35 with the second sealing ring 36 to be tightly pressed against the side of the filter plate 31, forming an adaptive elastic seal. This sealing structure can effectively compensate for gaps caused by thermal expansion and contraction or slight wear, preventing high-pressure melt from leaking from the slot.

[0045] To further enhance the stability of the filter plate 31 under high pressure and prevent it from being pushed out by the melt pressure, several fixing bolts 37 are provided on the die head 30. The threads of the fixing bolts 37 pass through the die head 30 and are finally screwed into the threaded holes reserved on the filter plate 31, thereby locking the filter plate 31 on the die head 30.

[0046] Work process:

[0047] Start heater 22 to heat melting cylinder 12, homogenizing cylinder 13 and die head 30 to the preset process temperature, such as 260-280℃.

[0048] Add the dried and qualified recycled polyester chips into the hopper 20, start the main motor, and the twin screws 21 rotate to convey and compact the chips from the feeding cylinder 11.

[0049] The material enters the melting cylinder 12 area and, under the combined action of the heat provided by the heater 22 and the strong shear heat brought about by the high-speed rotation of the screw 21, it quickly melts into a viscous flow state. The water-cooled jacket 23 is activated in a timely manner according to the feedback of the temperature sensor to ensure the stability of the melt temperature. Subsequently, the melt enters the homogenizing cylinder 13 and is fully mixed.

[0050] The uniform melt is pumped into the die head 30 by the screw 21 at a stable pressure. Inside the die head 30, the melt passes through the filter screen 32 on the filter plate 31, and solid impurities are effectively intercepted. The clean melt is extruded from the die orifice of the die head 30 and enters the subsequent spinning or pelletizing process.

[0051] When the filter screen 32 is clogged with impurities, causing the melt pressure to be too high, the operator can loosen the fixing bolt 37, pull out the old filter plate 31 through the handle 33, quickly replace it with a new filter plate 31 equipped with a clean filter screen 32, and then tighten the fixing bolt 37 again to resume production. The operation is convenient.

[0052] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A heating and melting apparatus for recycled polyester chips, comprising a barrel (10) and a die head (30) connected thereto, characterized in that, It also includes a filter plate (31) and a filter screen (32) disposed thereon, and the top of the machine head (30) is provided with a slot for accommodating the filter plate (31); A number of springs (34) are installed in the annular groove provided on the inner wall of the slot. A second sealing ring (36) is provided on the annular plate (35) on which the springs (34) are fixed. The inclined surface provided on the outer ring of the annular plate (35) cooperates with the inclined surface provided on the side wall of the filter plate (31) to push the annular plate (35) to compress the springs (34). The spring (34) is used to drive the second sealing ring (36) to adhere to the side wall of the filter plate (31).

2. The heating and melting apparatus for recycled polyester chips according to claim 1, characterized in that, The barrel (10) includes, in sequence along the material extrusion direction, a feeding cylinder (11), at least one melting cylinder (12), and a homogenizing cylinder (13) fixedly connected by several mounting bolts (14).

3. The heating and melting apparatus for recycled polyester chips according to claim 2, characterized in that, The number of the melting cylinders (12) is two.

4. The heating and melting device for recycled polyester chips according to claim 2, characterized in that: The top of the feeding cylinder (11) is fixed with a hopper (20), and two screws (21) are provided in the inner cavity of the machine cylinder (10).

5. The heating and melting apparatus for recycled polyester chips according to claim 2, characterized in that, The outer ring of the melting cylinder (12) is provided with a heater (22) and a water-cooling jacket (23).

6. The heating and melting apparatus for recycled polyester chips according to claim 2, characterized in that, The connecting surfaces of the feeding cylinder (11), the melting cylinder (12), the homogenizing cylinder (13), and the die head (30) are provided with a first sealing ring (24).

7. The heating and melting apparatus for recycled polyester chips according to claim 1, characterized in that, Several fixing bolts (37) provided on the machine head (30) are threaded through the machine head (30) and threadedly connected to the filter plate (31).

8. The heating and melting apparatus for recycled polyester chips according to claim 1, characterized in that, The filter plate (31) is provided with a handle (33) on its top.

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