PE particle deoiling equipment and PE particle deoiling method

Abstract

The invention discloses PE (polyethylene) particle deoiling equipment and a PE particle deoiling method. The equipment comprises a shell, a rotary drum, a driving mechanism, a tilting mechanism, a spraying system and a heating device, wherein the rotary drum is arranged in the shell and can rotate around the axis of the rotary drum, the driving mechanism is used for driving the rotary drum to rotate, the tilting mechanism is used for driving the feeding end of the rotary drum to swing up and down, the spraying system is arranged in the rotary drum, and the heating device is arranged in the shell. By driving the tilting mechanism and the driving mechanism, the rotary drum sequentially completes the whole-process operation of inclined feeding, horizontal rotary cleaning, rotary drying and inclined discharging. The problem that in the prior art, physical deoiling of PE particles is not thorough is solved, efficient and automatic chemical cleaning and drying are achieved by combining the rotating function and the tilting function, oil stains inside and outside the particles can be thoroughly removed, and the purity and quality of the recycled PE particles are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer material post-processing, and in particular to a PE particle deoiling device and a PE particle deoiling method. Background Art

[0002] During the production process of lithium battery separators, a large amount of scraps and defective products are generated. In order to achieve a circular economy and reduce costs, these waste materials containing polyethylene (PE) and white oil are usually recycled and remade into PE particles through processes such as dissolution, stretching, and pelletizing. However, due to the deep mixing of PE and white oil in the separator production process, the recycled PE particles contain a high level of oil pollution (mainly white oil). After these oil-containing particles are sold to the downstream industrial chain, the presence of oil pollution will significantly reduce the physical strength and purity of the PE material itself, resulting in more defects in applications such as blown film and injection molding. The scope of application is limited and can only be used to manufacture low-end products with low performance requirements, and the economic value is greatly reduced.

[0003] Currently, the industry generally uses physical methods to deoil PE particles. The most common solution is high-speed drying in a centrifuge. This method relies primarily on centrifugal force to remove oil from the particle surface, which has a certain effect on removing liquid oil on the particle surface. However, as a high-molecular polymer material, PE particles have a complex internal structure, and oil can penetrate and remain within the particles. During the centrifugation process, the oil inside the particles has difficulty penetrating the external PE matrix and being effectively separated. Therefore, physical centrifugation can usually only remove some oil from the particle surface, but is unable to remove the oil inside the particles, resulting in incomplete deoiling and a large amount of white oil remaining in the PE particles.

[0004] Therefore, how to provide a deoiling device and method that can completely remove the oil stains inside PE particles and improve the purity of the particles has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] The purpose of the present invention is to provide a PE particle deoiling device and a PE particle deoiling method, aiming to solve the technical problem in the prior art that the physical centrifugation method is not used to completely deoil the oil-containing PE particles, resulting in insufficient particle purity and strength.

[0006] The present invention provides a PE particle deoiling device, comprising:

[0007] case;

[0008] The rotating drum is rotatably arranged in the housing around its own axis, and the drum has a feeding end and a transmission end;

[0009] A driving mechanism is connected to the driving end of the rotating drum and is used to drive the drum to rotate;

[0010] A tilting mechanism is drivably connected to the feed end of the rotating drum and is used to drive the feed end to swing up and down to switch between an upward tilt position for feeding and a downward tilt position for discharging;

[0011] The spraying system includes at least one spray head fixedly arranged inside the rotating drum, which is used to spray the cleaning solvent onto the PE particles rolling in the rotating drum;

[0012] The heating device is arranged in the shell and is used to heat the rotating drum to gasify the cleaning solvent remaining on the PE particles.

[0013] Optionally, the driving mechanism includes a motor, a gearbox connected to the motor, and a transmission universal joint connected between the gearbox and the transmission end of the rotating drum.

[0014] Optionally, the tilting mechanism is a cylinder, one end of which is hinged to the housing, and the other end of which is hinged to the feed end of the rotating drum.

[0015] Optionally, the heating device includes a drying fan and a heater, and the hot air outlet of the drying fan is arranged in the shell and faces the outer wall of the rotating drum.

[0016] Optionally, a mixed liquid recovery system is further included. The mixed liquid recovery system is arranged as a whole just below the rotating drum and is used to collect the mixed liquid flowing out of the rotating drum.

[0017] Optionally, an exhaust gas recovery system is further included, wherein one end of the exhaust gas removal duct of the exhaust gas recovery system is connected to the upper part of the shell, and is used to collect the cleaning solvent vaporized during the drying process.

[0018] Optionally, the upward tilt position is when the feed end of the rotating drum forms an upward tilt angle of 15-45 degrees with the horizontal plane, and the downward tilt position is when the feed end of the rotating drum forms a downward tilt angle of 15-45 degrees with the horizontal plane.

[0019] Optionally, the mixed liquor recovery system includes:

[0020] A receiving tray for receiving the mixed liquid;

[0021] a mixed liquid collection box connected to the liquid receiving tray;

[0022] a liquid separation tank connected to the mixed liquid collection tank;

[0023] A mixed liquid pump provided between the mixed liquid collecting tank and the liquid separation tank;

[0024] Collection tank level gauge used to monitor the liquid level in the mixed liquid collection tank.

[0025] A second aspect of the present invention provides a method for deoiling PE particles using the PE particle deoiling device according to any one of the first aspects of the present invention, comprising the following steps:

[0026] Feeding step: drive the tilting mechanism to move the feed end of the rotating drum to the upward tilt position, and add the PE particles to be deoiled into the rotating drum;

[0027] Cleaning steps: drive the tilting mechanism to restore the rotating drum to the horizontal working position, start the driving mechanism to rotate the rotating drum, and simultaneously start the spraying system to spray the cleaning solvent onto the PE particles;

[0028] Drying step: stop the spray system, start the heating device to heat the rotating drum, and keep the rotating drum rotating;

[0029] Discharging step: stop the heating device and the driving mechanism, drive the tilting mechanism to move the feeding end of the rotating drum to a downward tilt position to discharge the deoiled and dried PE particles.

[0030] Optionally, in the washing step, the washing solvent is dichloromethane.

[0031] The technical content disclosed in the present invention has the following beneficial effects:

[0032] By utilizing a horizontal rotating drum and innovatively combining a drive mechanism, tilting mechanism, spray system, and heating device, the system achieves fully automated processing of PE pellets, including feeding, uniform tumbling cleaning, efficient drying, and automatic discharge. Compared to existing technologies, this invention employs the principle of chemical cleaning, utilizing a cleaning solvent with excellent oil-dissolving properties (e.g., the miscibility of dichloromethane and white oil). The tumbling action of the drum allows the solvent to fully and evenly contact the PE particles, penetrating deeply into the particles and completely dissolving and removing internal oil contaminants that are difficult to remove with traditional physical methods, thereby achieving near-100% deep deoiling. This thorough deoiling significantly improves the purity and physical strength of the recovered PE pellets. Furthermore, the equipment integrates solvent recovery and exhaust gas treatment systems, achieving efficient chemical recycling, reducing production costs, and avoiding organic solvent fugitive pollution, meeting green production requirements. The entire process boasts a high degree of automation, stable operation, and simple operation, providing a new, efficient, environmentally friendly, and economical solution to the deoiling challenge in PE waste recycling and reuse.

[0033] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0035] Figure 1 Schematic diagram of the structure of the PE particle deoiling equipment in an embodiment of the present invention.

[0036] Figure 2 2. It is a front view of the PE particle deoiling equipment in an embodiment of the present invention.

[0037] Figure 3 1 is a top view of the PE particle deoiling equipment in an embodiment of the present invention.

[0038] Explanation of the accompanying symbols: 1. Rotating drum; 2. Dichloromethane nozzle; 3. Cylinder; 4. Dichloromethane spray pump; 5. Dichloromethane storage tank; 6. Transmission universal joint; 7. Gearbox; 8. Motor; 9. Drying fan; 10. Air outlet duct heater; 11. Exhaust gas duct; 12. Collection box liquid level gauge; 13. Mixed liquid pump; 14. Liquid separation tank; 15. Shell; 16. Liquid level gauge interface. DETAILED DESCRIPTION

[0039] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention.

[0040] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0041] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0042] In all examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0043] It should be noted that like reference numerals and letters refer to like items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0044] See also Figure 1 and Figure 2The present invention provides a PE particle deoiling device with four core processes: feeding, rolling spraying, drying, and discharging. The device primarily comprises a horizontal rotating drum (1), along with a supporting drive mechanism, tilting mechanism, spraying system, and heating device.

[0045] Figure 2 As shown, the entire device is enclosed by a sealed housing 15. Inside the housing 15, the core component is a rotating drum 1 that can be rotated around its own axis, which is used to accommodate and process PE particles. The rotating drum has a feed end and a transmission end.

[0046] The driving mechanism is connected with the transmission end of the rotary drum 1 and is used for driving the drum to rotate around its own axis when in the horizontal working position. In the present embodiment, it is composed of a motor 8, a gearbox 7 and a transmission universal joint 6.

[0047] The tilting mechanism is connected to the feed end of the rotating drum 1 and can drive the feed end to swing up and down to facilitate feeding and unloading. In this embodiment, the tilting mechanism is specifically a cylinder 3, one end of which is hinged to the housing 15 and the other end is hinged to the feed end of the rotating drum 1.

[0048] The adoption of a transmission universal joint is a key design of this solution. Its function is that it can effectively transmit the rotational power of the drive mechanism, while adapting to the angular changes caused by the swing of the rotating drum through the tilting mechanism, thereby ensuring that the equipment can flexibly switch between different working conditions such as cleaning, feeding and unloading.

[0049] The spray system is used to perform chemical cleaning and includes a dichloromethane storage tank 5, a dichloromethane spray pump 4, and a dichloromethane spray head 2 arranged above the interior of the rotating drum 1.

[0050] The heating device in this embodiment is specifically a drying system for removing residual solvent on the particles after cleaning, which includes a drying fan 9 and an air outlet duct heater 10.

[0051] In addition, the equipment is also integrated with a mixed liquid recovery system and an exhaust gas recovery system to achieve solvent recycling and environmental protection.

[0052] Workflow:

[0053] 1. Feeding unit

[0054] At the beginning of the operation, select "Start feeding" on the control panel of the equipment. The control program drives the tilting mechanism (cylinder 3) to move, and lifts the feed end of the rotating drum 1 to the upward tilt position. In this embodiment, the upward tilt position is that the feed end forms an angle of 15-45 degrees with the horizontal plane, for example, 30 degrees. This angle makes it easy for PE particles to slide smoothly into the deep of the drum by gravity, avoiding accumulation and blockage at the entrance. At this time, the staff will align the unloading hose containing the silo with the drum entrance, and the particles can enter the inside of the drum quickly and evenly. When a whole batch of particles is added, the operator clicks "Feeding Completed", and the tilting mechanism drives the rotating drum 1 to return to the horizontal working position. Subsequently, the drive mechanism starts, causing the drum to rotate at a low speed for a period of time (such as 60 seconds) to allow the particles inside to be evenly distributed, preparing for the subsequent spray cleaning.

[0055] 2. Rolling spray unit (cleaning unit)

[0056] After loading and internal material balance are complete, the equipment automatically enters tumbling spray mode. The drive mechanism continuously drives the rotating drum 1 at a preset, steady speed. This speed is optimized to ensure that the particles are fully tumbled and evenly exposed to the cleaning solvent, while avoiding excessive particle splashing or excessive wear due to excessive speed.

[0057] Simultaneously, the spray system activates, and dichloromethane spray pump 4 pumps dichloromethane (used as a cleaning solvent) from dichloromethane storage tank 5 to dichloromethane spray nozzle 2 inside the drum. Spray nozzle 2 evenly sprays dichloromethane onto the tumbling PE particles in the form of semi-atomized droplets. Because dichloromethane has excellent solubility in white oil, it quickly penetrates the particles, dissolving the encapsulated white oil.

[0058] Combine Figure 3 The dichloromethane dissolved in the white oil forms a mixed liquid, which drips under gravity through the filter holes of the drum (not shown) into the liquid receiving tray below. It then flows along the diversion structure into the mixed liquid collection tank. The mixed liquid collection tank is equipped with two level gauge interfaces 16, one above the other. These interfaces are connected to the collection tank level gauge 12. When the liquid level reaches the set high level, the level gauge 12 sends a signal, triggering the mixed liquid pump 13 to start, pumping the mixed liquid in the collection tank into the liquid separation tank 14 at the rear end.

[0059] In liquid separation tank 14, the mixed liquid is heated, taking advantage of the significant difference in boiling points between dichloromethane (boiling point approximately 39.8°C) and white oil (boiling point approximately 230°C). The dichloromethane vapor is vaporized, while the white oil remains at the bottom of the tank. The vaporized dichloromethane vapor is cooled in a condenser and then recondensed into liquid, returning to dichloromethane storage tank 5, thus recycling the cleaning solvent. The separated white oil can be collected and returned to other production lines for reuse.

[0060] According to experimental data, the spraying process lasts approximately three hours and completely removes the white oil from the particles. After the program-controlled spraying process reaches the preset time, the spray system stops, and the drum continues to rotate for a short period of time before remaining stationary for five minutes to allow the remaining mixed liquid to drip out. This concludes the rolling spray mode.

[0061] 3. Drying unit

[0062] After the spraying process is complete, the system automatically switches to drying mode. Rotating drum 1 begins rotating again to evenly heat the particles. Simultaneously, the heating device (i.e., drying fan 9 and outlet duct heater 10) activates, blowing 40°C hot air into the air ducts on both sides of the drum, heating the exterior of rotating drum 1. This temperature is above the boiling point of dichloromethane, sufficient to rapidly vaporize it, but well below the softening temperature of the PE particles, preventing damage.

[0063] Heat is transferred to the internal PE particles through the drum wall. The residual dichloromethane on the surface and inside of the particles is heated and vaporized, forming exhaust gas in the shell 15. The exhaust gas is extracted by the exhaust gas removal duct 11 at the top and sent to the exhaust gas recovery equipment. The exhaust gas recovery equipment can use a carbon fiber adsorption device to recover the dichloromethane vapor by utilizing the high efficiency of carbon fiber adsorption capacity. The adsorption saturated carbon fiber can be regenerated by passing steam. After the desorbed dichloromethane vapor and water vapor mixture is condensed and separated into oil and water, the recovered dichloromethane can be returned to the storage tank 5 for recycling.

[0064] After the drying process lasts for about 30 minutes, the dichloromethane on the particles is completely removed. The system automatically ends the drying mode and sounds an audible and visual alarm, prompting the operator to discharge the particles.

[0065] 4. Unloading unit

[0066] After receiving the drying completion signal, the operator prepares the ton bags for collection and clicks "Start Discharging" on the control panel. The control program again activates the tilting mechanism (cylinder 3), this time moving the feed end of the rotating drum 1 to a downward tilt position, for example, forming a downward angle of 15-45 degrees. Driven by gravity and the inner wall guide plates (not shown), the dry, clean PE particles quickly and completely slide out of the drum and into the ton bags.

[0067] After all the particles have been dumped, the operator clicks "End Discharge" and the tilting mechanism drives the rotating drum 1 back to its horizontal initial position. At this point, a complete PE particle deoiling cycle is completed and the equipment is ready for the next round of operation.

[0068] The equipment of the present invention offers both manual and automatic operating modes. The automatic mode is used for daily production. Except for the initial steps of loading and unloading, which require manual confirmation, the remaining processes are automatically completed by the control program. The manual mode is used for equipment commissioning and maintenance. It allows individual start and stop operations for any mechanism (such as the motor, fan, and pump), facilitating inspection and troubleshooting.

[0069] In summary, the present invention achieves automated, full-process processing of PE particles by organically integrating a rotating drum, drive mechanism, tilting mechanism, spray system, and heating device within a closed housing 15. In particular, the coordinated operation of the drive and tilting mechanisms, coupled with their ingenious connection via universal joints, solves the difficult problem of achieving both efficient horizontal rotary cleaning and convenient tilted loading and unloading within the same device. This results in a rational structural design and efficient and reliable operation.

[0070] Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It should be understood by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A PE particle deoiling device, characterized in that: include: case; A rotating drum is rotatably disposed in the housing about its own axis, and the drum has a feeding end and a transmission end; A driving mechanism, in driving connection with the driving end of the rotating drum, for driving the drum to rotate; a tilting mechanism, drivingly connected to the feed end of the rotating drum, for driving the feed end to swing up and down to switch between an upward tilt position for feeding and a downward tilt position for discharging; a spraying system comprising at least one spray head fixedly disposed inside the rotating drum, for spraying a cleaning solvent onto the PE particles tumbling inside the rotating drum; The heating device is arranged in the shell and is used to heat the rotating drum to gasify the cleaning solvent remaining on the PE particles.

2. The PE particle deoiling equipment according to claim 1, characterized in that: The driving mechanism includes a motor, a gearbox connected to the motor, and a transmission universal joint connected between the gearbox and the transmission end of the rotating drum.

3. The PE particle deoiling equipment according to claim 1, characterized in that: The tilting mechanism is a cylinder, one end of which is hinged to the shell, and the other end of which is hinged to the feeding end of the rotating drum.

4. The PE particle deoiling equipment according to claim 1, characterized in that: The heating device includes a drying fan and a heater. The hot air outlet of the drying fan is arranged in the shell and faces the outer wall of the rotating drum.

5. The PE particle deoiling equipment according to claim 1, characterized in that: The invention also comprises a mixed liquid recovery system, which is entirely arranged directly below the rotating drum and is used for collecting the mixed liquid flowing out of the rotating drum.

6. The PE particle deoiling equipment according to claim 1, characterized in that: It also includes an exhaust gas recovery system, one end of the exhaust gas removal duct of the exhaust gas recovery system is connected to the upper part of the shell, and is used to collect the cleaning solvent vaporized during the drying process.

7. The PE particle deoiling equipment according to claim 3, characterized in that: The upward tilt position is when the feed end of the rotating drum forms an upward tilt angle of 15-45 degrees with the horizontal plane, and the downward tilt position is when the feed end of the rotating drum forms a downward tilt angle of 15-45 degrees with the horizontal plane.

8. The PE particle deoiling equipment according to claim 5, characterized in that: The mixed liquid recovery system comprises: A receiving tray for receiving the mixed liquid; a mixed liquid collection box communicated with the liquid receiving tray; a liquid separation tank connected to the mixed liquid collection tank; A mixed liquid pump disposed between the mixed liquid collecting tank and the liquid separation tank; A collecting tank level gauge is used to monitor the liquid level in the mixed liquid collecting tank.

9. A method for deoiling PE particles using the PE particle deoiling equipment according to any one of claims 1 to 8, characterized in that: The following steps are involved: Feeding step: driving the tilting mechanism to move the feed end of the rotating drum to an upward tilt position, and adding the PE particles to be deoiled into the rotating drum; Cleaning step: driving the tilting mechanism to restore the rotating drum to a horizontal working position, starting the driving mechanism to rotate the rotating drum, and simultaneously starting the spraying system to spray the cleaning solvent onto the PE particles; Drying step: stopping the spraying system and starting the heating device to heat the rotating drum while keeping the rotating drum rotating; Discharging step: stopping the heating device and the driving mechanism, driving the tilting mechanism to move the feed end of the rotating drum to a downwardly inclined position to discharge the deoiled and dried PE particles.

10. The method for deoiling PE particles according to claim 9, characterized in that: In the cleaning step, the cleaning solvent is dichloromethane.

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