Barrel type dryer for recycling and crushing plastics

Abstract

The invention belongs to the field of drying equipment, and particularly relates to a plastic recycling and crushing barrel type dryer which comprises a workbench, a heating mechanism and a pressure adjusting device, a heat insulation box is fixedly installed on the workbench, a first hydraulic cylinder device is arranged under the heat insulation box, and a discharging device is fixedly connected to the upper end of the first hydraulic cylinder device; a drying cylinder is fixedly installed in the heat insulation box, a vertically-arranged conveying cylinder device is arranged in the drying cylinder, a discharging cylinder connected with the discharging device in a sealed and sliding mode is arranged at the lower end of the drying cylinder, the heating mechanisms are symmetrically installed on an outer side plate of the heat insulation box, and the pressure adjusting devices are arranged in the heating mechanisms. According to the plastic fragment drying device, it can be guaranteed that in the negative pressure state, contact between hot air and plastic fragments can be efficiently conducted, the drying efficiency is effectively improved, the water evaporation temperature is reduced, the plastic fragments are prevented from being softened and agglomerated due to high temperature, and the service life of the plastic fragments is prolonged. The product quality is improved.

Description

Technical Field

[0001] This invention belongs to the field of drying equipment, specifically relating to a cylindrical dryer for plastic recycling scraps. Background Technology

[0002] In the plastic recycling process, the washed scraps usually contain a large amount of surface moisture and must undergo effective drying before entering the subsequent granulation or molding processes. Drum dryers are widely used in this field due to their simple structure, large processing capacity, and continuous operation.

[0003] For example, Chinese patent application CN202223496023.5 discloses a drying device for recycling waste plastic granules. Hot air is introduced into the drying chamber, and a stirring rod is installed. A motor drives the stirring rod through a rotating shaft, agitating the plastic granules and bringing them into contact with the hot air. This device continuously introduces hot air into the drying chamber under normal pressure, relying on direct contact and convective heat exchange between the heat medium and the wet material to evaporate and remove moisture, thus achieving the drying function. This is also a common operating method for current drum dryers. However, the above-mentioned normal pressure heating drying method has significant efficiency bottlenecks. On the one hand, under normal pressure, the evaporation temperature of water is high, and the evaporation rate is limited by the environmental pressure. The heat energy is mainly used to heat the liquid water to its boiling point rather than for efficient phase change evaporation, resulting in low efficiency of moisture removal per unit of heat energy and high energy consumption. On the other hand, the hot airflow enters at one end and is naturally discharged or simply exhausted at the other end. The contact time and uniformity between the heat medium and the material are insufficient, easily leading to airflow short-circuiting or localized overheating. Heat is not fully absorbed before being discharged, resulting in low heat exchange efficiency. In addition, for some heat-sensitive plastic scraps, excessively high drying temperatures may cause the material to soften and clump, affecting product quality. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a plastic recycling scrap drum dryer. This dryer features a novel drum structure that ensures efficient contact between hot air and plastic scraps under negative pressure, effectively improving drying efficiency, reducing moisture evaporation temperature, preventing plastic scraps from softening and clumping due to high temperatures, and ultimately improving product quality.

[0005] To achieve the above objectives, the specific technical solution of the present invention is as follows: A plastic recycling scrap drum dryer includes a workbench, a heating mechanism, and a pressure regulating device. A heat insulation box is fixedly installed on the workbench. A vertically arranged first hydraulic cylinder is positioned directly below the heat insulation box, and a discharge device is fixedly connected to the upper end of the first hydraulic cylinder. A drying drum is fixedly installed inside the heat insulation box, and a vertically arranged conveying cylinder is located inside the drying drum. A discharge cylinder, which is slidably and sealingly connected to the discharge device, is located at the lower end of the drying drum. The heating mechanism includes a circulating air box, which is symmetrically installed on the outer side plate of the heat insulation box. A heating plate is located inside the circulating air box, and a horizontally arranged second hydraulic cylinder is located on the outer side plate of the circulating air box. The drying drum has symmetrically arranged horizontal guide air pipes, which are evenly distributed vertically and extend outwards through the heat insulation box, connecting the circulating air box and the drying drum. The pressure regulating device includes a partition plate, which is vertically and sealed within the circulating air box. The partition plate is connected to the second hydraulic cylinder device via a connecting rod. On the other side of the partition plate, there is a vent pipe corresponding to the guide air pipe. The vent pipe and the guide air pipe are slidably and sealed together. A filter disc is installed at the end of the vent pipe away from the partition plate, and an air hole is opened on the outer wall of the end of the vent pipe near the partition plate.

[0006] As a further feature of the above scheme, the heating plate device is fixedly installed between the partition and the heat insulation box, and a ventilation window is opened on the outer side plate of the circulating air box. A mounting bracket is provided at the center of the outer side plate of the circulating air box, and the mounting bracket is used to install the second hydraulic cylinder device.

[0007] As a further feature of the above solution, the partition is equipped with a valve device that can automatically control the on / off state of both sides of the partition. A sealing strip is provided on the outer edge of the partition, and the sealing strip is slidably and sealingly connected to the inner wall of the circulating air box.

[0008] As a further feature of the above solution, a guide plate is provided between the discharge cylinder and the lower inner wall of the drying cylinder so that the material can automatically slide into the discharge cylinder. The upper and lower end faces of the heat insulation box are respectively provided with an upper plate and a lower plate, which are respectively sealed to the upper and lower end faces of the drying cylinder. The upper plate is provided with a feeding device that communicates with the drying cylinder. The feeding device can add material into the drying cylinder. When the feeding device is closed, it seals the drying cylinder.

[0009] As a further provision of the above scheme, the discharge device includes a push rod, the lower end of which is fixedly connected to the output end of the first hydraulic cylinder device, and a sealing frustum is fixedly connected to the upper end of the push rod. A sealing ring is provided on the outer wall of the sealing frustum, and a limiting groove is opened at the center of the upper surface of the sealing frustum. The first hydraulic cylinder device drives the sealing frustum to move up and down, and the sealing frustum can be sealed to the discharge cylinder. When the sealing frustum is inside the discharge cylinder, it can seal the drying cylinder. When the sealing frustum is detached from the discharge cylinder, it can open the drying cylinder for automatic discharge.

[0010] As a further provision of the above scheme, the conveying cylinder device includes a conveying cylinder with the same central axis as the drying cylinder. The conveying cylinder has uniformly distributed through holes. The lower end face of the conveying cylinder is provided with a circumferentially arranged lower grid plate, and the upper end face of the conveying cylinder is provided with a circumferentially arranged upper grid plate. The upper end of the upper grid plate is fixedly connected to the upper plate, and the lower end of the lower grid plate is fixedly connected to the guide inclined plate. The conveying cylinder is vertically installed inside the drying cylinder.

[0011] As a further feature of the above scheme, the upper end of the outer wall of the conveying cylinder is provided with circumferentially arranged, downwardly oriented throwing plates, which serve to scatter materials.

[0012] As a further feature of the above scheme, a rotating shaft is rotatably connected inside the conveying cylinder, and a spiral auger blade is provided on the rotating shaft. A drive motor is driven and connected to the upper end of the rotating shaft, and the drive motor is fixedly mounted on the upper plate. The lower end of the rotating shaft is driven and connected to a limiting circular groove to ensure the stability of the rotating shaft.

[0013] The beneficial effects of this invention are: After plastic fragments are added to the drying cylinder via the feeding device, the feeding device and the air valve are closed. Simultaneously, the sealing frustum moves into the discharge cylinder. At this point, the drying cylinder and the circulating air box inside the partition form an interconnected, sealed drying space. The heating plate device heats the air in the circulating air box inside the partition. Simultaneously, the second hydraulic cylinder device is activated, and both second hydraulic cylinder devices retract synchronously. Through the connecting rod, they drive the two partitions to move outward synchronously, creating a sealed drying space with appropriate negative pressure within the circulating air box inside the drying cylinder and partition, thus establishing a stable negative pressure. After the environment is set up, the two second hydraulic cylinders operate synchronously. One second hydraulic cylinder retracts while the other extends synchronously, and this operation is performed periodically to ensure that the negative pressure environment remains constant. The hot air in the circulating air box is circulated into the drying cylinder through the air pipe and guide air pipe, ensuring full contact with the plastic fragments. This device can ensure efficient contact between hot air and plastic fragments under negative pressure, effectively improving drying efficiency. Furthermore, the moisture evaporation temperature is reduced under negative pressure, lowering the drying temperature and preventing the plastic fragments from softening and clumping due to high temperature, thus improving product quality.

[0014] During drying, plastic fragments come into contact with the auger blades through the lower grid plate. The drive motor rotates the shaft, which in turn rotates the auger blades, conveying the plastic fragments upwards. When the plastic fragments reach the top, they pass through the upper grid plate and are guided by the throwing inclined plate, causing the plastic fragments to be thrown downwards. This process causes the plastic fragments to circulate up and down within the drying drum, increasing the contact between the hot air and the plastic fragments and further improving drying efficiency. Attached Figure Description

[0015] Figure 1 This is a cross-sectional schematic diagram of the present invention; Figure 2 This is a schematic diagram of the structure of the present invention; Figure 3 This is a schematic diagram of the cross-section of the drying cylinder of the present invention; Figure 4 This is a schematic cross-sectional view of the heat insulation box of the present invention; Figure 5 This is a schematic diagram showing the positions of the conveying cylinder device and the discharge device of the present invention; Figure 6 This is a schematic diagram of the heating mechanism structure of the present invention; Figure 7 This is a first schematic diagram of the pressure regulating device of the present invention; Figure 8 This is a second schematic diagram of the pressure regulating device of the present invention.

[0016] 1. Workbench; 2. First hydraulic cylinder device; 3. Heat insulation box; 301. Upper plate; 302. Lower plate; 303. Feeding device; 4. Drying cylinder; 401. Guide air pipe; 402. Guide inclined plate; 403. Discharge cylinder; 5. Conveying cylinder device; 501. Conveying cylinder; 5011. Through hole; 5012. Lower grid plate; 5013. Upper grid plate; 502. Discharge inclined plate; 503. Rotating shaft; 5031. Spiral auger blades; 504. Drive motor; 6. Heating Mechanism; 601, Circulating air box; 6011, Vent window; 602, Mounting bracket; 603, Second hydraulic cylinder device; 604, Heating plate device; 7, Pressure regulating device; 701, Partition plate; 7011, Sealing strip; 702, Air valve device; 703, Connecting rod; 704, Vent pipe; 7041, Air hole; 7042, Filter disc; 8, Discharge device; 801, Push rod; 802, Sealing frustum; 803, Sealing ring; 804, Limiting groove. Detailed Implementation

[0017] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0018] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The following will refer to the appendix... Figures 1-8 This application will be described in detail with reference to the embodiments.

[0019] This embodiment discloses a plastic recycling scrap drum dryer, including a workbench 1, a heating mechanism 6, and a pressure regulating device 7. A heat insulation box 3 is fixedly installed on the workbench 1. A vertically arranged first hydraulic cylinder device 2 is provided directly below the heat insulation box 3. A discharge device 8 is fixedly connected to the upper end of the first hydraulic cylinder device 2. A drying drum 4 is fixedly installed inside the heat insulation box 3. A vertically arranged conveying cylinder device 5 is provided inside the drying drum 4. A discharge cylinder 403 is provided at the lower end of the drying drum 4 and is slidably and sealingly connected to the discharge device 8. The heating mechanism 6 includes a circulating air box 601. The circulating air box 601 is symmetrically installed on the outer side plate of the heat insulation box 3. A heating plate device 604 is provided inside the circulating air box 601. A horizontally arranged second hydraulic cylinder device 603 is provided on the outer side plate of the circulating air box 601. A horizontally arranged guide air pipe 401 is symmetrically arranged on the drying drum 4. The guide air pipe 401 is evenly distributed in the vertical direction and passes outward through the heat insulation box 3 to connect the circulating air box 601 and the drying drum 4.

[0020] like Figure 6 , Figure 7 , Figure 8 As shown, the pressure regulating device 7 includes a partition 701, which is vertically and sealed within the circulating air box 601. The partition 701 is connected to the second hydraulic cylinder device 603 via a connecting rod 703. On the other side of the partition 701, there is a vent pipe 704 corresponding to the guide air pipe 401. The vent pipe 704 is slidably and sealed with the guide air pipe 401. A filter disc 7042 is installed at the end of the vent pipe 704 away from the partition 701. An air hole 7041 is opened on the outer wall of the end of the vent pipe 704 near the partition 701. The filter disc 7042 can prevent plastic fragments from entering the vent pipe 704 and also serves to clean the guide air pipe 401.

[0021] The partition 701 is equipped with a valve device 702, which can automatically control the on / off state of both sides of the partition 701. The outer edge of the partition 701 is equipped with a sealing strip 7011, which is slidably and sealingly connected to the inner wall of the circulating air box 601.

[0022] like Figure 6 As shown, the heating plate device 604 is fixedly installed between the partition 701 and the heat insulation box 3, and can heat the air in the circulating air box 601. A ventilation window 6011 is opened on the outer side plate of the circulating air box 601. A mounting bracket 602 is provided at the center of the outer side plate of the circulating air box 601. The mounting bracket 602 is used to install the second hydraulic cylinder device 603.

[0023] like Figure 3 , Figure 4As shown, a guide plate 402 is provided between the discharge cylinder 403 and the lower inner wall of the drying cylinder 4 so that the material can automatically slide into the discharge cylinder 403. The upper and lower end faces of the heat insulation box 3 are respectively provided with an upper plate 301 and a lower plate 302. The upper plate 301 and the lower plate 302 are respectively sealed to the upper and lower end faces of the drying cylinder 4. The upper plate 301 is provided with a feeding device 303 that communicates with the drying cylinder 4. The feeding device 303 can add material into the drying cylinder 4. When the feeding device 303 is closed, it seals the drying cylinder 4.

[0024] like Figure 3 , Figure 5 As shown, the discharge device 8 includes a push rod 801. The lower end of the push rod 801 is fixedly connected to the output end of the first hydraulic cylinder device 2. A sealing frustum 802 is fixedly connected to the upper end of the push rod 801. A sealing ring 803 is provided on the outer wall of the sealing frustum 802. A limiting groove 804 is opened at the center of the upper end face of the sealing frustum 802. The first hydraulic cylinder device 2 drives the sealing frustum 802 to move up and down. The sealing frustum 802 can be sealed to the discharge cylinder 403. When the sealing frustum 802 is inside the discharge cylinder 403, it can seal the drying cylinder 4. When the sealing frustum 802 is separated from the discharge cylinder 403, it can open the drying cylinder 4 for automatic discharge.

[0025] The conveying cylinder device 5 includes a conveying cylinder 501 with the same central axis as the drying cylinder 4. The conveying cylinder 501 has evenly distributed through holes 5011. The lower end face of the conveying cylinder 501 is provided with a lower grid plate 5012 arranged in a circle, and the upper end face of the conveying cylinder 501 is provided with an upper grid plate 5013 arranged in a circle. The upper end of the upper grid plate 5013 is fixedly connected to the upper plate 301, and the lower end of the lower grid plate 5012 is fixedly connected to the guide inclined plate 402. The conveying cylinder 501 is vertically installed in the drying cylinder 4. The upper end of the outer wall of the conveying cylinder 501 is provided with a circumferentially arranged inclined throwing plate 502 that is inclined downward. The inclined throwing plate 502 plays the role of throwing materials.

[0026] A rotating shaft 503 is rotatably connected inside the conveying cylinder 501. The rotating shaft 503 is equipped with spiral auger blades 5031. A drive motor 504 is connected to the upper end of the rotating shaft 503. The drive motor 504 is fixedly installed on the upper plate 301. The lower end of the rotating shaft 503 is slidably connected to the limiting circular groove 804 to ensure the stability of the rotating shaft 503.

[0027] The working process of this equipment is as follows: When the equipment is working, plastic fragments are added to the drying cylinder 4 through the feeding device 303. After the feeding device 303 is closed, the air valve device 702 is closed, and at the same time, the sealing frustum 802 moves into the discharge cylinder 403. At this time, the drying cylinder 4 and the circulating air box 601 inside the partition 701 form an interconnected and sealed drying space. The heating plate device 604 heats the air in the circulating air box 601 inside the partition 701. Simultaneously, the second hydraulic cylinder device 603 is started, and the two second hydraulic cylinder devices 603 retract synchronously. Rod 703 drives the two partitions 701 to move outward synchronously, forming a closed drying space with appropriate negative pressure in the drying cylinder 4 and the circulating air box 601 inside the partitions 701. After a stable negative pressure environment is formed, the two second hydraulic cylinder devices 603 operate synchronously. One second hydraulic cylinder device 603 retracts and the other second hydraulic cylinder device 603 extends synchronously and operates periodically to ensure that the negative pressure environment remains unchanged. At the same time, the hot air in the circulating air box 601 is circulated into the drying cylinder 4 through the air pipe 704 and the guide air pipe 401 to fully contact the plastic fragments.

[0028] During the drying process, plastic fragments come into contact with the spiral auger blades 5031 through the lower grid plate 5012. The drive motor 504 drives the rotating shaft 503 to rotate, which in turn drives the spiral auger blades 5031 to rotate, conveying the plastic fragments upward. When the plastic fragments reach the top, they pass through the upper grid plate 5013 and are guided by the throwing inclined plate 502, causing the plastic fragments to be thrown downward. This causes the plastic fragments to circulate and be conveyed up and down in the drying drum 4, increasing the contact between the hot air and the plastic fragments.

[0029] When it is necessary to discharge hot and humid gas, when the sealed spaces of the two circulating air boxes 601 are the same size, the two second hydraulic cylinder devices 603 contract synchronously, causing the two partitions 701 to move away from each other. The air valve device 702 slowly opens, and the outside gas enters the sealed space of the circulating air box 601 through the air valve device 702. At this time, the drying space in the circulating air box 601 inside the drying cylinder 4 and the partition 701 is converted to a normal pressure state. The air in the circulating air box 601 is in a relatively dry and hot state, and the air in the drying cylinder 4 is in a relatively humid and hot state. The air valve device 702 is closed, and the two second hydraulic cylinder devices 603 extend synchronously, causing the two partitions 701 to move closer to each other. The feeding device 303 is opened, and the hot and humid air in the drying cylinder 4 is discharged upwards. The relatively dry and hot air in the circulating air box 601 enters the drying cylinder 4, automatically completing the dehumidification and air exchange.

[0030] After drying, the first hydraulic cylinder device 2 drives the sealing truncated cone 802 to descend, the sealing truncated cone 802 disengages from the discharge cylinder 403, the drive motor 504 drives the rotating shaft 503 to reverse, the spiral auger blades 5031 drive the plastic fragments downward, and the plastic fragments are automatically discharged from the discharge cylinder, completing the automatic discharge.

[0031] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0032] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined.

Claims

1. A drum dryer for recycled plastic scraps, comprising a worktable, a heating mechanism, and a pressure regulating device, characterized in that, A heat insulation box is fixedly installed on the workbench. A vertically arranged first hydraulic cylinder device is located directly below the heat insulation box. A discharge device is fixedly connected to the upper end of the first hydraulic cylinder device. A drying cylinder is fixedly installed inside the heat insulation box. A vertically arranged conveying cylinder device is located inside the drying cylinder. A discharge cylinder that is sealed and slidably connected to the discharge device is located at the lower end of the drying cylinder. The heating mechanism includes a circulating air box, which is symmetrically installed on the outer side plate of the heat insulation box. A heating plate device is located inside the circulating air box. A horizontally arranged second hydraulic cylinder device is located on the outer side plate of the circulating air box. A horizontally arranged guide air pipe is symmetrically arranged on the drying cylinder. The guide air pipe is evenly distributed in the vertical direction and passes outward through the heat insulation box to connect the circulating air box and the drying cylinder. The pressure regulating device includes a partition plate, which is vertically and sealed within the circulating air box. The partition plate is connected to the second hydraulic cylinder device via a connecting rod. On the other side of the partition plate, there is a vent pipe corresponding to the guide air pipe. The vent pipe and the guide air pipe are slidably and sealed together. A filter disc is installed at the end of the vent pipe away from the partition plate, and an air hole is opened on the outer wall of the end of the vent pipe near the partition plate.

2. The plastic recycling scrap drum dryer according to claim 1, characterized in that, The heating plate device is fixedly installed between the partition and the heat insulation box. A ventilation window is opened on the outer side plate of the circulating air box, and a mounting bracket is provided at the center of the outer side plate of the circulating air box.

3. The plastic recycling scrap drum dryer according to claim 2, characterized in that, The partition is equipped with an air valve device, which can automatically control the on / off state of both sides of the partition. A sealing strip is provided on the outer edge of the partition, and the sealing strip is slidably and sealingly connected to the inner wall of the circulating air box.

4. The plastic recycling scrap drum dryer according to claim 2, characterized in that, A guide plate is provided between the discharge cylinder and the lower inner wall of the drying cylinder. The upper and lower end faces of the heat insulation box are respectively provided with an upper plate and a lower plate. The upper plate and the lower plate are respectively sealed to the upper and lower end faces of the drying cylinder. The upper plate is provided with a feeding device that communicates with the drying cylinder.

5. The plastic recycling scrap drum dryer according to claim 4, characterized in that, The discharge device includes a push rod, the lower end of which is fixedly connected to the output end of the first hydraulic cylinder device, and a sealing frustum is fixedly connected to the upper end of the push rod. A sealing ring is provided on the outer wall of the sealing frustum, and a limit groove is opened at the center of the upper surface of the sealing frustum.

6. The plastic recycling scrap drum dryer according to claim 4, characterized in that, The conveying cylinder device includes a conveying cylinder with the same central axis as the drying cylinder. The conveying cylinder has evenly distributed through holes. The lower end face of the conveying cylinder is provided with a circumferentially arranged lower grid plate, and the upper end face of the conveying cylinder is provided with a circumferentially arranged upper grid plate. The upper end of the upper grid plate is fixedly connected to the upper plate, and the lower end of the lower grid plate is fixedly connected to the guide inclined plate. The conveying cylinder is installed vertically inside the drying cylinder.

7. The plastic recycling scrap drum dryer according to claim 6, characterized in that, The upper end of the outer wall of the conveying cylinder is provided with circumferentially arranged, downward-sloping throwing plates.

8. The plastic recycling scrap drum dryer according to claim 5, characterized in that, The conveying cylinder is rotatably connected to a rotating shaft, which is equipped with spiral auger blades. The upper end of the rotating shaft is connected to a drive motor, which is fixedly mounted on the upper plate. The lower end of the rotating shaft is slidably connected to a limiting circular groove.

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