Oil gas purification device and method in waste plastic pyrolysis system

Abstract

The application discloses an oil-gas purification device and method in a waste plastic pyrolysis system, and belongs to the technical field of waste plastic resource utilization, which comprises an outer cylinder, a tangential gas inlet arranged in the side wall of the outer cylinder, an inner cylinder coaxially fixed at the top of the inner cylinder, an exhaust cover fixed at the top of the outer cylinder and communicating with the inner cylinder, a collection bin fixed at the bottom of the outer cylinder for collecting heavy oil and solid slag, and a surplus oil discharge port arranged at the side of the collection bin for discharging surplus heavy oil. The shaft rod with fan blades and spiral scrapers is coaxially arranged in the outer cylinder and the inner cylinder, the kinetic energy of the gas flow discharged after purification can be directly used to drive the rotation of the fan blades, and a power driving unit is not needed, so that energy saving and consumption reduction are realized, the spiral scraper is simultaneously driven to continuously scrape the inner wall of the outer cylinder, the agglomerates formed by the solid phase coke powder and the viscous heavy oil drops in the pyrolysis oil gas are prevented from adhering to the cylinder wall, the device flow channel is effectively prevented from being blocked, and long-term continuous and stable operation of the device is ensured.

Description

Technical Field

[0001] This invention relates to a purification device, and more particularly to an oil and gas purification device in a waste plastic pyrolysis system. This invention also relates to a purification method, and more particularly to an oil and gas purification method in a waste plastic pyrolysis system, belonging to the field of waste plastic resource utilization technology. Background Technology

[0002] Currently, the industry generally adopts a combination process of high-temperature cyclone dust collector and subsequent high-temperature spray scrubbing tower for gas-solid purification of oil and gas from waste plastic pyrolysis. First, the high-temperature cyclone dust collector removes most of the large-diameter solid particles in the oil and gas by relying on the principle of centrifugal force, completing the primary gas-solid separation. Then, the high-temperature spray scrubbing tower uses the self-produced heavy oil from pyrolysis as the washing medium to perform countercurrent spray scrubbing on the oil and gas after cyclone treatment, completing the deep purification and removing ultrafine solid particles and sticky heavy components that cannot be effectively removed by the cyclone.

[0003] However, in the long-term industrial application process, the oil and gas from the pyrolysis of waste plastics not only contain solid coke powder particles, but also a large number of sticky heavy oil droplets, gum and asphalt components. The solid particles and sticky oil droplets are very easy to form agglomerates, which then adhere to the inner wall of the cyclone, affecting the purification effect. In addition, subsequent separate spray washing is not only complicated, but also increases the purification cost.

[0004] To address this issue, an oil and gas purification device and method for a waste plastic pyrolysis system were designed to optimize the aforementioned problems. Summary of the Invention

[0005] The main objective of this invention is to provide an oil and gas purification device and method in a waste plastic pyrolysis system, in order to solve the problems of material adhesion on the inner wall of the cyclone separator, poor purification effect of a single centrifugal dust removal method, cumbersome purification process, and high equipment operating cost in the prior art.

[0006] The objective of this invention can be achieved by adopting the following technical solution: An oil and gas purification device in a waste plastic pyrolysis system includes an outer cylinder, a tangential air inlet on the side wall of the outer cylinder, an inner cylinder coaxially fixed to the top of the outer cylinder, an exhaust hood fixed to the top of the outer cylinder and communicating with the inside of the inner cylinder, a collection bin fixed to the bottom of the outer cylinder for collecting heavy oil and solid residue, and an excess oil outlet on the side of the collection bin for discharging excess heavy oil. The outer cylinder and the inner cylinder are coaxially equipped with a scraping mechanism. The scraping mechanism is powered by the purified oil flow discharged through the inner cylinder and is used to continuously self-clean the inner wall of the outer cylinder. The bottom end of the inner cylinder is fitted with a spray pipe in a circumferential manner, and the top of the exhaust hood is equipped with an oil circulation mechanism, which is used to transport the heavy oil that settles in the collection bin to the spray pipe for spraying. The power input end of the oil circulation mechanism is linked with the scraping mechanism. The bottom of the inner cylinder is also equipped with a vibration mechanism. The vibration end of the vibration mechanism faces the outer wall of the inner cylinder and is used to vibrate and strike the outer wall of the inner cylinder. The power input end of the vibration mechanism is linked with the scraping mechanism. The tangential air inlet is equipped with a wind speed regulation mechanism, which is used to adaptively adjust the flow cross-sectional area of ​​the tangential air inlet according to the flow rate of the pyrolysis oil inlet.

[0007] Preferably, the scraping mechanism includes a shaft coaxially rotatably mounted inside the outer cylinder and the inner cylinder. A fan blade is fixed at the upper part of the shaft inside the inner cylinder, and a spiral scraper is fixed at the outer side of the shaft in the annular cavity between the outer cylinder and the inner cylinder. The outer edge of the spiral scraper slides against the inner wall of the outer cylinder. The fan blade is driven to rotate by the oil and gas flow passing through the inner cylinder and being discharged into the exhaust hood, which drives the shaft and the spiral scraper to rotate synchronously.

[0008] Preferably, the wind speed adjustment mechanism includes a rotating shaft rotatably installed inside the tangential air inlet, a baffle fixed on the outside of the rotating shaft, and a spring-loaded spring between the two ends of the rotating shaft and the inner wall of the tangential air inlet. The baffle rotates around the rotating shaft under the thrust of the airflow, and in conjunction with the restoring force of the spring-loaded spring, adaptively adjusts the flow cross-sectional area of ​​the tangential air inlet.

[0009] Preferably, the oil circulation mechanism includes a power compartment fixed to the top of the exhaust hood, the top end of the shaft extends into the interior of the power compartment, a turntable is fixed to the top end of the shaft, a lever is fixed to the eccentric part of the top of the turntable, a rectangular frame plate is slidably arranged inside the power compartment, and the lever extends to the inner side of the rectangular frame plate and slides in cooperation with the inner wall of the rectangular frame plate. The two ends of the rectangular frame plate are symmetrically fixed with sliding rods, and the two ends of the inner wall of the power compartment are symmetrically fixed with fixing blocks. The sliding rods and the fixing blocks are slidably connected. The power compartment has cylinders fixed symmetrically at both ends, and pistons are slidably installed inside the cylinders. The end of the slide rod away from the rectangular frame plate is fixedly connected to the piston. The end of the cylinder is connected to a suction pipe and a discharge pipe. The end of the suction pipe away from the cylinder extends to the bottom of the collection chamber, and the end of the discharge pipe away from the cylinder is connected to a spray pipe. Both the suction pipe and the discharge pipe are equipped with a one-way valve.

[0010] Preferably, the vibration mechanism includes a crossbar fixed at the middle position of the shaft, the crossbar being located at the bottom of the inner cylinder, and a mounting plate vertically fixed at the end of the crossbar away from the shaft. The mounting plate is located on the outer side of the inner cylinder, and a mounting groove is provided on the inner side of the mounting plate. An insert block is slidably disposed inside the mounting groove, and a return spring is provided between the insert block and the inner end of the mounting groove. A protrusion that cooperates with the insert block is fixed on the outer side of the inner cylinder. When the insert block rotates with the shaft, it intermittently abuts against and slides off the protrusion. The spring force of the return spring drives the insert block to pop out, vibrating and striking the inner cylinder.

[0011] Preferably, a filter cylinder is fixed to the top of the collection chamber. The filter cylinder is funnel-shaped, and a sheet scraper is fixed to the outside of the shaft. The outer edge of the sheet scraper slides against the inner wall of the filter cylinder to scrape and clean the inner wall of the filter cylinder.

[0012] Preferably, the bottom of the collection chamber is provided with a solid slag discharge pipe, the top of the solid slag discharge pipe is connected to the bottom of the filter cartridge, the bottom of the solid slag discharge pipe is provided with a switch valve, the bottom of the shaft extends into the interior of the solid slag discharge pipe, and a spiral conveying blade is fixed on the outer side of the shaft at the position inside the solid slag discharge pipe.

[0013] Preferably, the residual oil outlet is located at the bottom of the side wall of the collection chamber, and a control valve is installed on the residual oil outlet.

[0014] Preferably, multiple sets of spray holes are evenly opened on the outer side of the spray pipe along the circumference, and the spray direction of the spray holes is opposite to the direction of the rising oil and gas, forming countercurrent spray washing.

[0015] The present invention also provides a method for purifying oil and gas in a waste plastic pyrolysis system, comprising the following steps: Step 1: The oil and gas generated by the pyrolysis of waste plastics are introduced into the outer cylinder through the tangential air inlet. The airflow forms a swirling flow along the inner wall of the outer cylinder. The centrifugal force is used to achieve the primary separation of large-diameter solid particles and heavy oil droplets in the oil and gas. The separated solid particles and heavy components settle into the collection chamber at the bottom of the outer cylinder. Step 2: After primary separation, the oil and gas flow upward and enter the inner cylinder through the bottom end. The oil and gas flow upward and is discharged through the exhaust hood, which drives the scraping mechanism to continuously self-clean and scrape the inner wall of the outer cylinder, scraping off the agglomerates adhering to the inner wall into the collection chamber. Step 3: While the scraping mechanism is running, the oil circulation mechanism is driven to work in conjunction to extract the heavy oil that has settled in the collection bin and transport it to the spray pipe for spraying. The rising oil and gas are washed by countercurrent spraying to capture ultrafine solid particles and remaining viscous heavy components in the oil and gas, thus completing the deep purification of the oil and gas. Step 4: While the scraping mechanism is running, the vibration mechanism is driven to work in conjunction to intermittently vibrate and knock on the outer wall of the inner cylinder, accelerating the shaking and peeling off of the agglomerates adhering to the cylinder wall and avoiding blockage of the flow channel of the device; Step 5: The wind speed adjustment mechanism in the tangential air inlet adaptively adjusts the flow cross-sectional area of ​​the tangential air inlet according to the real-time air intake rate of the pyrolysis oil and gas, stably controls the flow rate of the oil and gas entering the outer cylinder, and ensures the centrifugal separation effect. Step 6: The oil and gas after deep purification are discharged through the exhaust hood to the subsequent condensation process. The excess heavy oil in the collection chamber is discharged through the excess oil outlet, and the collected solid slag is continuously discharged through the solid slag discharge pipe at the bottom of the collection chamber.

[0016] The beneficial effects of this invention are as follows: This invention provides an oil and gas purification device and method in a waste plastic pyrolysis system. By coaxially arranging a shaft with fan blades and a spiral scraper in the outer and inner cylinders, the fan blades can be directly driven to rotate by the kinetic energy of the gas discharged after purification, without the need for an additional power drive unit. While achieving energy saving and consumption reduction, it simultaneously drives the spiral scraper to continuously scrape the inner wall of the outer cylinder, preventing agglomerates formed by solid coke powder and viscous heavy oil droplets in the pyrolysis oil and gas from adhering to the cylinder wall, effectively preventing blockage of the device flow channel, and ensuring long-term continuous and stable operation of the device. By installing a spray pipe at the bottom of the outer side of the inner cylinder, and using the oil circulation mechanism composed of the power chamber at the top of the exhaust hood, turntable, lever, rectangular frame plate, slide rod, fixed block, cylinder, piston, suction pipe, and discharge pipe in linkage with the shaft, the heavy oil settled in the collection chamber at the bottom of the device can be automatically extracted as a washing medium and sprayed through the spray pipe to achieve self-sufficiency and self-circulation of the washing oil. The spraying process can efficiently capture ultrafine solid particles and residual viscous heavy components that are difficult to remove from the oil and gas after centrifugal treatment, achieving deep separation of gas and solid as well as gas and liquid, and significantly improving the oil and gas purification accuracy and treatment effect. By setting a vibration mechanism consisting of a crossbar, mounting plate, mounting groove, insert block, return spring, and protrusion at the bottom of the inner cylinder, which is also linked with the shaft, the inner cylinder and the main body of the device can be continuously vibrated during the operation of the device. This not only accelerates the shaking and peeling off of the agglomerates adhering to the cylinder wall, but also forms a synergistic anti-clogging effect with the spiral scraper scraping operation, improving the cleaning efficiency of the device wall. It can also effectively avoid the blockage caused by the accumulation of solid particles and sticky components at the top of the collection chamber, ensuring the smooth progress of solid-liquid sedimentation and gas-solid separation processes. By setting an adaptive wind speed adjustment mechanism consisting of a rotating shaft, baffle, and spring at the tangential air inlet, the flow cross-sectional area of ​​the tangential air inlet can be automatically adjusted according to the real-time air intake rate of the pyrolysis oil and gas through the dynamic balance between the thrust of the intake airflow and the restoring force of the spring. This stabilizes the flow rate and swirling intensity of the oil and gas entering the outer cylinder, ensuring that the device can maintain a stable and efficient centrifugal separation effect under different load conditions, thus improving the applicability of the device. Attached Figure Description

[0017] Figure 1 This is a front view schematic diagram of the present invention; Figure 2 This is a schematic front sectional view of the present invention along the axial direction; Figure 3 This is a schematic diagram of the internal structure of the outer cylinder of the present invention; Figure 4 This is a schematic cross-sectional view of the tangential air inlet of the present invention; Figure 5 This is a schematic diagram of the overall transmission structure of the present invention; Figure 6 This is a schematic diagram of the internal structure of the collection chamber of the present invention; Figure 7 This is a top view of the interior of the power compartment of the present invention; Figure 8 This is a schematic diagram of the internal side section structure of the power compartment of the present invention; Figure 9 This is a partially enlarged schematic diagram of the vibration mechanism of the present invention.

[0018] In the diagram: 1. Outer cylinder; 2. Tangential air intake; 201. Shaft; 202. Baffle; 203. Spring; 3. Inner cylinder; 4. Exhaust hood; 5. Collection bin; 501. Residual oil discharge outlet; 6. Scraping mechanism; 601. Shaft; 602. Fan blade; 603. Spiral scraper; 7. Spray pipe; 8. Oil circulation mechanism; 801. Power compartment; 802. Turntable; 803. Lever; 804. Rectangular frame plate; 805. Slide rod; 806. Fixing block; 807. Cylinder block; 808. Piston; 809. Suction pipe; 810. Drain pipe; 9. Vibration mechanism; 901. Crossbar; 902. Mounting plate; 903. Mounting groove; 904. Insert block; 905. Return spring; 906. Protrusion; 10. Filter cartridge; 11. Flake scraper; 12. Solid slag discharge pipe; 13. Screw conveyor blades. Detailed Implementation

[0019] To enable those skilled in the art to more clearly understand the technical solution of the present invention, the present invention will be further described in detail below with reference to embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0020] like Figures 1-9As shown, this embodiment provides an oil and gas purification device in a waste plastic pyrolysis system, including an outer cylinder 1, a tangential air inlet 2 opened on the side wall of the outer cylinder 1, an inner cylinder 3 coaxially fixed to the top of the outer cylinder 1, an exhaust hood 4 fixed to the top of the outer cylinder 1 and communicating with the inside of the inner cylinder 3, a collection bin 5 fixed to the bottom of the outer cylinder 1 for collecting heavy oil and solid residue, and an excess oil outlet 501 on the side of the collection bin 5 for discharging excess heavy oil. The outer cylinder 1 and the inner cylinder 3 are coaxially equipped with a scraping mechanism 6. The scraping mechanism 6 is powered by the purified oil flow discharged through the inner cylinder 3 and is used to continuously self-clean the inner wall of the outer cylinder 1. The bottom end of the inner cylinder 3 is circumferentially fitted with a spray pipe 7, and the top of the exhaust hood 4 is provided with an oil circulation mechanism 8, which is used to transport the heavy oil that settles in the collection bin 5 to the spray pipe 7 for spraying. The power input end of the oil circulation mechanism 8 is linked with the scraping mechanism 6. The bottom end of the inner cylinder 3 is also provided with a vibration mechanism 9. The vibration end of the vibration mechanism 9 faces the outer wall of the inner cylinder 3 and is used to vibrate and strike the outer wall of the inner cylinder 3. The power input end of the vibration mechanism 9 is linked and cooperates with the scraping mechanism 6. The tangential air inlet 2 is equipped with a wind speed adjustment mechanism, which is used to adaptively adjust the flow cross-sectional area of ​​the tangential air inlet 2 according to the flow rate of the pyrolysis oil inlet 2.

[0021] The high-temperature oil and gas generated from the pyrolysis of waste plastics is tangentially introduced into the outer cylinder 1 through the tangential air inlet 2, forming a high-speed swirling flow along the inner wall of the outer cylinder 1. Under the action of centrifugal force, large-diameter solid coke powder particles, heavy oil droplets, and resinous and asphaltene components entrained in the oil and gas are thrown towards the inner wall of the outer cylinder 1, completing the primary gas-solid and gas-liquid separation. The separated solid particles and heavy components slide down the inner wall of the outer cylinder 1 and settle into the collection chamber 5 at the bottom of the outer cylinder 1. The oil and gas after primary separation flows upward along the annular cavity between the outer cylinder 1 and the inner cylinder 3, and then flows through the inner cylinder 3... The oil and gas enter the inner cylinder 3 through the bottom opening, continue to flow upwards, and are eventually discharged through the exhaust hood 4 to the subsequent condensation process. During the upward flow of oil and gas and its discharge through the exhaust hood 4, the airflow drives the scraping mechanism 6 to operate continuously. The scraping mechanism 6 continuously scrapes the inner wall of the outer cylinder 1, scraping off the solid particles and agglomerates of viscous heavy components adhering to the inner wall into the collection bin 5, achieving self-cleaning of the device without power. Simultaneously, the scraping mechanism 6 drives the oil circulation mechanism 8 and the vibration mechanism 9 in conjunction with each other. The oil circulation mechanism 8... The heavy oil that settles in the collection chamber 5 is continuously extracted and transported to the spray pipe 7 at the bottom of the inner cylinder 3 for spraying. This counter-current spraying washes the rising oil and gas, capturing ultrafine solid particles and remaining viscous heavy components that cannot be removed by centrifugal separation, thus completing deep purification of the oil and gas. The vibration mechanism 9 intermittently vibrates and strikes the outer wall of the inner cylinder 3, accelerating the shaking and peeling off of agglomerates adhering to the outer wall of the inner cylinder 3 and the inner wall of the outer cylinder 1, while preventing blockage of the flow channels and filter cartridge 10 within the device. The wind speed regulation mechanism in the tangential air inlet 2 adjusts the airflow according to the pyrolysis oil and gas flow rate. The real-time air intake rate adaptively adjusts the flow cross-sectional area of ​​the tangential air intake port 2, stably controlling the oil and gas flow rate and swirling intensity entering the outer cylinder 1, ensuring that the device can maintain a stable centrifugal separation effect under different air intake loads; part of the heavy oil that settles in the collection chamber 5 is recycled for spray washing through the oil circulation mechanism 8, and the excess heavy oil is discharged from the device through the excess oil discharge port 501, while the settled solid slag is discharged through the solid slag discharge pipe 12 at the bottom of the collection chamber 5, completing the entire process of oil and gas purification, self-cleaning, material circulation and slag discharge.

[0022] In this embodiment, the scraping mechanism 6 includes a shaft 601 coaxially rotatably installed inside the outer cylinder 1 and the inner cylinder 3. A fan blade 602 is fixed at the upper part of the shaft 601 inside the inner cylinder 3. A spiral scraper 603 is fixed at the outer side of the shaft 601 in the annular cavity between the outer cylinder 1 and the inner cylinder 3. The outer edge of the spiral scraper 603 slides against the inner wall of the outer cylinder 1. The fan blade 602 is driven to rotate by the oil and gas flow passing through the inner cylinder 3 and being discharged into the exhaust hood 4, which drives the shaft 601 and the spiral scraper 603 to rotate synchronously.

[0023] The purified oil and gas flowing upward through the inner cylinder 3 and discharged into the exhaust hood 4 continuously impacts the fan blades 602 inside the inner cylinder 3, driving the fan blades 602 to rotate at high speed around the axis of the shaft 601. When the fan blades 602 rotate, they drive the shaft 601 to rotate synchronously, which in turn drives the spiral scraper 603 fixed on the shaft 601 to rotate synchronously. During the rotation of the spiral scraper 603, its outer edge always maintains sliding contact with the inner wall of the outer cylinder 1. Through the spiral blade structure, it continuously scrapes down the agglomerates formed by solid coke powder and viscous heavy oil droplets that are adhering to the inner wall of the outer cylinder 1. The scraped agglomerates slide down along the guide of the spiral scraper 603 and finally settle into the collection chamber 5 at the bottom, thus achieving continuous self-cleaning of the inner wall of the outer cylinder 1.

[0024] In this embodiment, the wind speed adjustment mechanism includes a rotating shaft 201 rotatably installed inside the tangential air inlet 2. A baffle 202 is fixed on the outside of the rotating shaft 201. A spring spring 203 is provided between the two ends of the rotating shaft 201 and the inner wall of the tangential air inlet 2. The baffle 202 rotates around the rotating shaft 201 under the thrust of the airflow. With the restoring force of the spring spring 203, the flow cross-sectional area of ​​the tangential air inlet 2 is adaptively adjusted.

[0025] When pyrolysis oil and gas enter the outer cylinder 1 through the tangential inlet 2, the airflow exerts a continuous thrust on the baffle 202, causing it to rotate around the shaft 201. The rotation of the shaft 201 causes the springs 203 at both ends to deform, generating a reverse restoring force. As the oil and gas intake rate increases, the thrust on the baffle 202 increases, the rotation angle of the baffle 202 increases, and the flow cross-sectional area of ​​the tangential inlet 2 increases accordingly. This prevents throttling pressure drop at the tangential inlet 2, ensuring the stability of the oil and gas flow. When the oil and gas intake rate decreases, the thrust of the airflow on the baffle 202 decreases, and the restoring force of the spring 203 drives the rotating shaft 201 to rotate in the opposite direction to the baffle 202, reducing the flow cross-sectional area of ​​the tangential air inlet 2, thereby increasing the oil and gas flow rate into the outer cylinder 1, ensuring that the oil and gas can form a sufficiently strong vortex in the outer cylinder 1, and maintaining a stable centrifugal separation effect; through the dynamic balance between the airflow thrust and the restoring force of the spring 203, the adaptive adjustment of the flow cross-sectional area of ​​the tangential air inlet 2 is achieved.

[0026] In this embodiment, the oil circulation mechanism 8 includes a power chamber 801 fixed to the top of the exhaust hood 4, the top end of the shaft 601 extends into the interior of the power chamber 801, a turntable 802 is fixed to the top end of the shaft 601, a lever 803 is fixed to the eccentric part of the top of the turntable 802, a rectangular frame plate 804 is slidably arranged inside the power chamber 801, and the lever 803 extends into the inner side of the rectangular frame plate 804 and slides in cooperation with the inner wall of the rectangular frame plate 804. The two ends of the rectangular frame plate 804 are symmetrically fixed with sliding rods 805, and the two ends of the inner wall of the power compartment 801 are symmetrically fixed with fixing blocks 806. The sliding rods 805 and the fixing blocks 806 are slidably connected. The power compartment 801 has cylinders 807 symmetrically fixed at both ends inside. A piston 808 is slidably arranged inside the cylinder 807. The end of the slide rod 805 away from the rectangular frame plate 804 is fixedly connected to the piston 808. The end of the cylinder 807 is connected to a suction pipe 809 and a drain pipe 810. The end of the suction pipe 809 away from the cylinder 807 extends to the bottom of the collection chamber 5. The end of the drain pipe 810 away from the cylinder 807 is connected to the spray pipe 7. Both the suction pipe 809 and the drain pipe 810 are equipped with a one-way valve.

[0027] When the shaft 601 rotates under the drive of the fan blade 602, it drives the turntable 802 at its top to rotate synchronously. When the turntable 802 rotates, it drives the eccentrically mounted lever 803 at its top to perform circular motion around the axis of the turntable 802. During the circular motion, the lever 803 always slides against the inner wall of the rectangular frame plate 804, thereby pushing the rectangular frame plate 804 to perform reciprocating linear motion in the horizontal direction. When the rectangular frame plate 804 reciprocates, it drives the sliding rods 805 at both ends to slide synchronously along the fixed block 806, thereby pushing the pistons 808 in the cylinders 807 at both ends to perform reciprocating extension and retraction motion inside the cylinders 807. When the pistons 808 slide to the outside of the cylinders 807, a negative pressure is formed inside the cylinders 807. At this time, the one-way valve on the suction pipe 809 opens, and the liquid is discharged. When the one-way valve on pipe 810 is closed, the heavy oil settled in collection chamber 5 is drawn into cylinder 807 via suction pipe 809. When piston 808 slides into cylinder 807, positive pressure is formed inside cylinder 807. At this time, the one-way valve on suction pipe 809 is closed, and the one-way valve on discharge pipe 810 is opened. The heavy oil in cylinder 807 is pumped into spray pipe 7 via discharge pipe 810, completing the extraction and transportation of heavy oil. Through the rotation of shaft 601, the double cylinders 807 alternately complete the suction and discharge operations, realizing a continuous and stable circulation supply of washing oil. No additional electric pumping equipment is required, further reducing the energy consumption and operating cost of the device. At the same time, centrifugal dust removal and spray washing are integrated, simplifying the purification process.

[0028] In this embodiment, the vibration mechanism 9 includes a crossbar 901 fixed at the middle position of the shaft 601. The crossbar 901 is located at the bottom of the inner cylinder 3. A mounting plate 902 is vertically fixed at the end of the crossbar 901 away from the shaft 601. The mounting plate 902 is located on the outside of the inner cylinder 3. A mounting groove 903 is provided on the inner side of the mounting plate 902. An insert 904 is slidably disposed inside the mounting groove 903. A return spring 905 is provided between the insert 904 and the inner end of the mounting groove 903. A protrusion 906 that cooperates with the insert 904 is fixed on the outside of the inner cylinder 3. When the insert 904 rotates with the shaft 601, it intermittently abuts against and slides off the protrusion 906. The spring force of the return spring 905 drives the insert 904 to pop out and vibrate and strike the inner cylinder 3.

[0029] When the shaft 601 rotates, it drives the crossbar 901, which is fixed in the middle, to rotate around the axis of the shaft 601. As the crossbar 901 rotates, it drives the mounting plate 902 at its end to move in a circular motion along the outer side of the inner cylinder 3. During the movement of the mounting plate 902, the insert 904 in its inner mounting groove 903 moves synchronously with the mounting plate 902. When the insert 904 moves to the position of the protrusion 906 on the outer side of the inner cylinder 3, the end of the insert 904 abuts against the protrusion 906. The protrusion 906 generates a reverse thrust on the insert 904, pushing the insert 904 to slide into the mounting groove 903, compressing the return spring 905. When the insert 904 continues to move with the mounting plate 902 and slides off the surface of the protrusion 906, the elastic force of the return spring 905 is released instantaneously, pushing... The movable insert 904 is quickly ejected from the outside of the mounting slot 903. The ejected insert 904 generates an instantaneous impact force on the outer wall of the inner cylinder 3, causing the inner cylinder 3 to vibrate. The shaft 601 continues to rotate, causing the insert 904 to intermittently abut and slide against multiple sets of protrusions 906, thereby generating continuous, high-frequency vibration impact on the outer wall of the inner cylinder 3. The vibration is transmitted to the entire device body through the inner cylinder 3. On the one hand, it accelerates the shaking and peeling off of the agglomerates adhering to the inner wall of the outer cylinder 1 and the outer wall of the inner cylinder 3, forming a synergistic anti-clogging effect with the scraping operation of the spiral scraper 603. On the other hand, it can avoid blockage caused by the accumulation of solid particles and viscous components in key flow channels such as the bottom opening of the inner cylinder 3 and the filter cartridge 10, ensuring the smoothness of the gas-solid separation and oil-gas flow process in the device.

[0030] In this embodiment, a filter cylinder 10 is fixed to the inner top of the collection chamber 5. The filter cylinder 10 is funnel-shaped, and a sheet scraper 11 is fixed to the outer side of the shaft 601. The outer edge of the sheet scraper 11 slides against the inner wall of the filter cylinder 10 to scrape and clean the inner wall of the filter cylinder 10.

[0031] The funnel-shaped filter cartridge 10 can perform solid-liquid separation on the oil-sludge mixture that settles into the collection bin 5, intercepting large-diameter solid particles and preventing solid particles from entering the lower layer of oil and causing blockage of the suction pipe 809, thus ensuring the stable operation of the oil circulation mechanism 8. At the same time, when the shaft 601 rotates, it drives the outer plate scraper 11 to rotate synchronously. During the rotation of the plate scraper 11, its outer edge always slides and adheres to the inner wall of the filter cartridge 10, continuously scraping the inner wall of the filter cartridge 10, continuously scraping off the filter cake, solid particles and sticky oil droplets attached to the inner wall of the filter cartridge 10, preventing the filter holes of the filter cartridge 10 from becoming blocked, ensuring the filtration throughput and long-term stable filtration effect of the filter cartridge 10. The scraped material slides down the funnel-shaped inner wall of the filter cartridge 10 and is finally discharged from the collection bin 5.

[0032] In this embodiment, the bottom of the collection chamber 5 is provided with a solid slag discharge pipe 12. The top end of the solid slag discharge pipe 12 is connected to the bottom end of the filter cylinder 10. The bottom end of the solid slag discharge pipe 12 is provided with a switch valve. The bottom end of the shaft 601 extends into the interior of the solid slag discharge pipe 12. A spiral conveying blade 13 is fixed on the outer side of the shaft 601 at the position inside the solid slag discharge pipe 12.

[0033] The solid phase and slag settling in the collection bin 5, as well as the solid phase material scraped off by the filter cartridge 10, all slide into the interior of the solid slag discharge pipe 12. When the shaft 601 rotates, it drives the spiral conveying blades 13 inside the solid slag discharge pipe 12 to rotate synchronously. When the spiral conveying blades 13 rotate, they generate a continuous downward conveying force on the solid slag through the spiral lead, continuously and stably conveying the solid phase and slag in the solid slag discharge pipe 12 downward. The opening and closing of the switch valve can be controlled according to the slag discharge requirements, and the spiral conveying blades 13 can be used to realize continuous or intermittent slag discharge operations, avoiding the accumulation and caking of solid slag in the collection bin 5, and ensuring the long-term continuous operation of the device. At the same time, the conveying power of the spiral conveying blades 13 also comes from the rotation of the shaft 601, eliminating the need for additional slag discharge drive equipment, further simplifying the device structure and reducing energy consumption.

[0034] In this embodiment, the excess oil outlet 501 is located at the bottom of the side wall of the collection chamber 5, and a control valve is provided on the excess oil outlet 501.

[0035] The heavy oil that settles in the collection chamber 5 is partially extracted by the oil circulation mechanism 8 for circulating spray washing. When the heavy oil level in the collection chamber 5 reaches the set height, the control valve on the excess oil outlet 501 is opened to discharge the excess heavy oil from the collection chamber 5 out of the device and transport it to the pyrolysis system for reuse or subsequent oil refining process. The discharge rate of the excess oil can be adjusted by the control valve, thereby stabilizing the heavy oil level in the collection chamber 5, ensuring that the suction pipe 809 of the oil circulation mechanism 8 is always immersed in the oil, avoiding the occurrence of cavitation, and ensuring the stable operation of the oil circulation mechanism 8.

[0036] In this embodiment, multiple sets of spray holes are uniformly opened along the circumferential direction on the outer side of the spray pipe 7, and the spray direction of the spray holes is opposite to the direction of the rising oil and gas, forming countercurrent spray washing.

[0037] After the heavy oil conveyed by the oil circulation mechanism 8 enters the spray pipe 7, it is sprayed outward through the spray holes evenly distributed around the outside of the spray pipe 7, forming an atomized oil curtain. This causes the atomized washing oil to come into countercurrent contact with the upward-flowing oil and gas, greatly increasing the contact area and contact time between the washing oil and the oil and gas. The washing oil can fully capture the ultrafine solid particles, residual colloids and asphalt and other viscous heavy components entrained in the oil and gas. The captured material drips downward with the washing oil and finally settles into the collection chamber 5, completing the deep spray purification of the oil and gas.

[0038] like Figures 1-9 As shown in the figure, this embodiment provides a method for purifying oil and gas in a waste plastic pyrolysis system. The process is as follows: Step 1: The oil and gas generated by the pyrolysis of waste plastics are introduced into the inner cylinder 1 through the tangential air inlet 2. The airflow forms a swirling flow along the inner wall of the outer cylinder 1. The centrifugal force is used to achieve the primary separation of large-diameter solid particles and heavy oil droplets in the oil and gas. The separated solid particles and heavy components settle into the collection chamber 5 at the bottom of the outer cylinder 1. Step 2: After primary separation, the oil and gas flow upward and enter the inner cylinder 3 through the bottom end of the inner cylinder 3. The oil and gas flow upward and is discharged through the exhaust hood 4, which drives the scraping mechanism 6 to run continuously and self-clean the inner wall of the outer cylinder 1, scraping the agglomerates adhering to the inner wall into the collection chamber 5. Step 3: While the scraping mechanism 6 is running, the oil circulation mechanism 8 is driven to work in conjunction to extract the heavy oil that has settled in the collection bin 5 and transport it to the spray pipe 7 for spraying. The rising oil and gas are washed by countercurrent spraying to capture ultrafine solid particles and remaining viscous heavy components in the oil and gas, thus completing the deep purification of the oil and gas. Step 4: While the scraping mechanism 6 is running, the vibration mechanism 9 is driven to work in conjunction to intermittently vibrate and knock on the outer wall of the inner cylinder 3, which accelerates the shaking and peeling off of the agglomerates adhering to the cylinder wall and avoids blockage of the flow channel of the device. Step 5: The wind speed regulating mechanism in the tangential air inlet 2 adaptively adjusts the flow cross-sectional area of ​​the tangential air inlet 2 according to the real-time air intake rate of the pyrolysis oil and gas, stabilizes and controls the flow rate of the oil and gas entering the outer cylinder 1, and ensures the centrifugal separation effect. Step 6: The oil and gas after deep purification are discharged through the exhaust hood 4 to the subsequent condensation process. The excess heavy oil in the collection chamber 5 is discharged through the excess oil outlet 501, and the collected solid slag is continuously discharged through the solid slag discharge pipe 12 at the bottom of the collection chamber 5.

[0039] The above description is merely a further embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope disclosed in the present invention, based on the technical solution and concept of the present invention, shall fall within the scope of protection of the present invention.

Claims

1. An oil and gas purification device in a waste plastic pyrolysis system, comprising an outer cylinder (1), a tangential air inlet (2) opened on the side wall of the outer cylinder (1), an inner cylinder (3) coaxially fixed to the top of the outer cylinder (1), an exhaust hood (4) fixed to the top of the outer cylinder (1) and communicating with the interior of the inner cylinder (3), a collection bin (5) fixed to the bottom of the outer cylinder (1) for collecting heavy oil and solid residue, and an excess oil outlet (501) on the side of the collection bin (5) for discharging excess heavy oil. Its features are: The outer cylinder (1) and the inner cylinder (3) are coaxially equipped with a scraping mechanism (6). The scraping mechanism (6) is powered by the purified oil flow discharged through the inner cylinder (3) and is used to continuously self-clean the inner wall of the outer cylinder (1). The bottom end of the inner cylinder (3) is fitted with a spray pipe (7) in a circumferential manner, and the top of the exhaust hood (4) is equipped with an oil circulation mechanism (8) for transporting the heavy oil that settles in the collection bin (5) to the spray pipe (7) for spraying out. The power input end of the oil circulation mechanism (8) is linked with the scraping mechanism (6). The bottom end of the inner cylinder (3) is also provided with a vibration mechanism (9). The vibration end of the vibration mechanism (9) faces the outer wall of the inner cylinder (3) and is used to vibrate and strike the outer wall of the inner cylinder (3). The power input end of the vibration mechanism (9) is linked with the scraping mechanism (6). The tangential air inlet (2) is equipped with a wind speed adjustment mechanism. The wind speed adjustment mechanism is used to adaptively adjust the flow cross-sectional area of ​​the tangential air inlet (2) according to the flow rate of the pyrolysis oil inlet (2).

2. The oil and gas purification device in a waste plastic pyrolysis system according to claim 1, characterized in that: The scraping mechanism (6) includes a shaft (601) coaxially rotatably installed inside the outer cylinder (1) and the inner cylinder (3). A fan blade (602) is fixed at the upper part of the shaft (601) inside the inner cylinder (3). A spiral scraper (603) is fixed at the outer side of the shaft (601) in the annular cavity between the outer cylinder (1) and the inner cylinder (3). The outer edge of the spiral scraper (603) slides against the inner wall of the outer cylinder (1). The fan blade (602) is driven to rotate by the oil and gas flow passing through the inner cylinder (3) and discharged to the exhaust hood (4), which drives the shaft (601) and the spiral scraper (603) to rotate synchronously.

3. The oil and gas purification device in a waste plastic pyrolysis system according to claim 1, characterized in that: The wind speed adjustment mechanism includes a rotating shaft (201) rotatably installed inside the tangential air inlet (2). A baffle (202) is fixed on the outside of the rotating shaft (201). A spring spring (203) is provided between the two ends of the rotating shaft (201) and the inner wall of the tangential air inlet (2). The baffle (202) rotates around the rotating shaft (201) under the thrust of the airflow. With the reset force of the spring spring (203), the flow cross-sectional area of ​​the tangential air inlet (2) is adaptively adjusted.

4. The oil and gas purification device in a waste plastic pyrolysis system according to claim 2, characterized in that: The oil circulation mechanism (8) includes a power chamber (801) fixed to the top of the exhaust hood (4), the top end of the shaft (601) extending into the interior of the power chamber (801), a turntable (802) fixed to the top end of the shaft (601), a lever (803) fixed to the eccentric top of the turntable (802), a rectangular frame plate (804) slidingly arranged inside the power chamber (801), and the lever (803) extending into the inner side of the rectangular frame plate (804) and slidingly engaging with the inner wall of the rectangular frame plate (804); The two ends of the rectangular frame plate (804) are symmetrically fixed with sliding rods (805), and the two ends of the inner wall of the power compartment (801) are symmetrically fixed with fixing blocks (806). The sliding rods (805) and the fixing blocks (806) are slidably connected. The power compartment (801) has cylinders (807) fixed symmetrically at both ends inside. A piston (808) is slidably arranged inside the cylinder (807). The end of the slide rod (805) away from the rectangular frame plate (804) is fixedly connected to the piston (808). The end of the cylinder (807) is connected to a suction pipe (809) and a drain pipe (810). The end of the suction pipe (809) away from the cylinder (807) extends to the bottom of the collection chamber (5). The end of the drain pipe (810) away from the cylinder (807) is connected to the spray pipe (7). Both the suction pipe (809) and the drain pipe (810) are equipped with a one-way valve.

5. The oil and gas purification device in a waste plastic pyrolysis system according to claim 2, characterized in that: The vibration mechanism (9) includes a crossbar (901) fixed at the middle position of the shaft (601). The crossbar (901) is located at the bottom of the inner cylinder (3). A mounting plate (902) is vertically fixed at one end of the crossbar (901) away from the shaft (601). The mounting plate (902) is located on the outside of the inner cylinder (3). A mounting groove (903) is provided on the inner side of the mounting plate (902). An insert (904) is slidably arranged inside the mounting groove (903). A return spring (905) is provided between the insert (904) and the inner end of the mounting groove (903). A protrusion (906) that cooperates with the insert (904) is fixed on the outside of the inner cylinder (3). When the insert (904) rotates with the shaft (601), it intermittently abuts against and slides off the protrusion (906). The spring force of the return spring (905) drives the insert (904) to pop out and vibrate and strike the inner cylinder (3).

6. The oil and gas purification device in a waste plastic pyrolysis system according to claim 2, characterized in that: A filter cylinder (10) is fixed to the top of the collection chamber (5). The filter cylinder (10) is funnel-shaped. A sheet scraper (11) is fixed to the outside of the shaft (601). The outer edge of the sheet scraper (11) slides against the inner wall of the filter cylinder (10) to scrape and clean the inner wall of the filter cylinder (10).

7. The oil and gas purification device in a waste plastic pyrolysis system according to claim 6, characterized in that: The bottom of the collection chamber (5) is provided with a solid slag discharge pipe (12). The top end of the solid slag discharge pipe (12) is connected to the bottom end of the filter cylinder (10). The bottom end of the solid slag discharge pipe (12) is provided with a switch valve. The bottom end of the shaft (601) extends into the interior of the solid slag discharge pipe (12). The outer side of the shaft (601) is fixed with a spiral conveying blade (13) inside the solid slag discharge pipe (12).

8. The oil and gas purification device in a waste plastic pyrolysis system according to claim 1, characterized in that: The residual oil outlet (501) is located at the bottom of the side wall of the collection chamber (5), and a control valve is installed on the residual oil outlet (501).

9. The oil and gas purification device in a waste plastic pyrolysis system according to claim 1, characterized in that: Multiple sets of spray holes are evenly opened on the outer side of the spray pipe (7) along the circumference. The spray direction of the spray holes is opposite to the direction of the rising oil and gas, forming countercurrent spray washing.

10. A method for purifying oil and gas in a waste plastic pyrolysis system, based on an oil and gas purification device for a waste plastic pyrolysis system according to any one of claims 1-9, characterized in that, Includes the following steps: Step 1: The oil and gas generated by the pyrolysis of waste plastics are introduced into the interior of the outer cylinder (1) through the tangential air inlet (2). The airflow forms a swirling flow along the inner wall of the outer cylinder (1). The centrifugal force is used to achieve the primary separation of large-diameter solid particles and heavy oil droplets in the oil and gas. The separated solid particles and heavy components settle into the collection chamber (5) at the bottom of the outer cylinder (1). Step 2: After primary separation, the oil and gas flow upward and enter the inner cylinder (3) through the bottom end of the inner cylinder (3). The oil and gas flow upward and is discharged through the exhaust hood (4) to drive the scraping mechanism (6) to continuously self-clean and scrape the inner wall of the outer cylinder (1), scraping the agglomerates adhering to the inner wall into the collection bin (5). Step 3: While the scraping mechanism (6) is running, the oil circulation mechanism (8) is driven to work to extract the heavy oil that has settled in the collection bin (5) and transport it to the spray pipe (7) for spraying. The rising oil and gas are washed by countercurrent spraying to capture the ultrafine solid particles and the remaining viscous heavy components in the oil and gas, thus completing the deep purification of the oil and gas. Step 4: While the scraping mechanism (6) is running, the vibration mechanism (9) is driven to work in conjunction to intermittently vibrate and knock on the outer wall of the inner cylinder (3) to accelerate the shaking and peeling off of the agglomerates adhering to the cylinder wall and avoid blockage of the flow channel of the device. Step 5: The wind speed adjustment mechanism in the tangential air inlet (2) adjusts the flow cross-sectional area of ​​the tangential air inlet (2) according to the real-time air intake rate of the pyrolysis oil and gas, stabilizes and controls the flow rate of the oil and gas entering the outer cylinder (1), and ensures the centrifugal separation effect. Step 6: The oil and gas after deep purification are discharged through the exhaust hood (4) to the subsequent condensation process. The excess heavy oil in the collection bin (5) is discharged through the excess oil outlet (501). The collected solid slag is continuously discharged through the solid slag discharge pipe (12) at the bottom of the collection bin (5).

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