A two-stage cracked gasoline hydrorefining unit

Abstract

This invention discloses a two-stage cracked gasoline hydrorefining device, comprising: a feedstock pretreatment unit, a first-stage low-temperature selective hydrogenation unit, an intermediate precision fractionation unit, a second-stage high-temperature deep hydrogenation unit, a product stabilization and refining unit, and a hydrogen circulation and replenishment unit connected in sequence. The feedstock pretreatment unit includes: a base platform, a premixing mechanism, a feedstock storage system, a feedstock conveying system, a filtration system, a feedstock buffering system, a first conveying pump group, a dehydration system, and a second conveying pump group. This two-stage cracked gasoline hydrorefining device, through an adaptive dual-source independent throttling adjustment mechanism, can achieve ratio control of circulating hydrogen and replenished hydrogen from two gas sources, and can adaptively adjust the aeration height and gas distribution position in real time to achieve layered, full-area, and dead-angle-free microporous gas distribution, expanding the gas-liquid two-phase contact area and disturbance range.

Description

Technical Field

[0001] This invention relates to the field of deep processing of ethylene and refining of aromatics in the petrochemical industry, specifically a two-stage cracked gasoline hydrorefining device. Background Technology

[0002] Cracked gasoline is an important high-value-added liquid byproduct produced in the steam cracking of petroleum hydrocarbons to produce ethylene. It is rich in high-value aromatic components such as benzene, toluene, and xylene, with aromatics accounting for 60%–80% of its total mass. It is a core high-quality feedstock for the large-scale industrial extraction and production of BTX light aromatics, possessing extremely high resource utilization value. The crude cracked gasoline directly produced from the cracking unit has a complex composition. In addition to high-value aromatic components, it is also enriched with a large amount of unsaturated reactive hydrocarbons such as conjugated dienes and styrene. These reactive components are chemically active and readily undergo reactions during storage and heat exchange. Oxidation, polymerization, gumming, and coking reactions can easily cause problems such as equipment blockage, catalyst carbon buildup and deactivation, and increased pressure drop in the unit. At the same time, crude cracked gasoline feedstock generally contains thiophene-type organic sulfur, cyclic organic nitrogen, organic acid and organic oxygen, which are difficult-to-remove heteroatom impurities. These impurities not only seriously poison the subsequent hydrorefining catalyst, reducing its activity and service life, but also affect the purity and color of aromatic products, resulting in substandard quality of refined products. Therefore, crude cracked gasoline must undergo a refined hydrorefining pretreatment process to remove unsaturated active components and harmful heteroatom impurities in order to meet the feedstock requirements for subsequent aromatic extraction and refining. In the existing technical field, in the gas-liquid mixing process of pyrolysis gasoline hydrotreating pretreatment, hydrogen supply mostly adopts a single-path gas inlet mode with a fixed opening. This generally suffers from low accuracy in hydrogen-to-oil ratio adjustment and poor adaptability to operating conditions. During variable load production, the unit is prone to local hydrogen content being too high or hydrogen deficiency imbalance, which leads to decreased selectivity of the hydrotreating reaction, increased side reactions, intensified feedstock gelation, and shortened catalyst life. At the same time, traditional aeration and gas distribution structures are mostly fixed installation layouts with limited gas-liquid contact range, which easily leads to gas phase floating and coalescence, local liquid phase retention, and poor gas-liquid mixing uniformity. This results in insufficient stability of the oil-hydrogen mixture system, causing large fluctuations in the physical properties of the feedstock for subsequent hydrotreating reactions, directly affecting the quality stability of hydrorefined products and the overall operational fault tolerance of the unit. Summary of the Invention

[0003] The purpose of this invention is to provide a two-stage cracked gasoline hydrorefining apparatus to at least solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a two-stage cracked gasoline hydrorefining apparatus, comprising: a feedstock pretreatment unit, a first-stage low-temperature selective hydrogenation unit, an intermediate precision fractionation unit, a second-stage high-temperature deep hydrogenation unit, a product stabilization and refining unit, and a hydrogen circulation and replenishment unit connected in sequence; the first-stage low-temperature selective hydrogenation unit adopts a liquid-phase hydrogenation low-temperature condition and is filled with a selective hydrogenation catalyst for the removal of dienes and styrene; the second-stage high-temperature deep hydrogenation unit adopts a gas-phase hydrogenation high-temperature condition and is filled with a sulfurized hydrorefining catalyst for olefin saturation and heteroatom removal; the intermediate precision fractionation unit is equipped with a C5 removal tower and a C9 removal tower, and only the C6-C8 central fraction is fed into the second-stage hydrogenation unit; The raw material pretreatment unit includes: Base platform; A premixing mechanism is located at the top left front of the base platform; The raw material storage system is fixedly installed at the top right front of the base platform; The raw material conveying system is fixedly installed on the top of the base platform and located on the front side of the raw material storage system. The discharge end of the raw material storage system is connected to the inlet end of the raw material conveying system. The filtration system is fixedly installed at the top of the base platform and located on the outside left side of the raw material conveying system. The discharge end of the raw material conveying system is connected to the inlet end of the filtration system. The raw material buffer system is fixedly installed on the top of the base platform and located on the rear side of the filter system. The discharge end of the filter system is connected to the inlet end of the raw material buffer system. The first conveying pump unit is fixedly installed at the top of the base platform and located on the lower left side of the raw material buffer system. The discharge end of the raw material buffer system is connected to the inlet end of the first conveying pump unit. The dewatering system is fixedly installed at the top of the base platform and located on the outer left side of the first conveying pump group. The discharge end of the first conveying pump group is connected to the inlet end of the dewatering system. The second conveying pump unit is fixedly installed at the top of the base platform and located on the front side of the dewatering system. The discharge end of the dewatering system is connected to the inlet end of the second conveying pump unit.

[0005] Preferably, the premixing mechanism includes: a vertical frame, an outer tank, an inner tank, an electrically controlled valve, a heat exchanger, a feed connector, a gas supply component, and a mixing component; the vertical frame is fixedly installed on the top of the base platform in the vertical direction; the outer tank is fixedly installed on the inner side of the vertical frame in the vertical direction; the inner tank is fixedly installed below the inner cavity of the vertical frame via a bracket in the vertical direction; the electrically controlled valve is connected to the bottom of the discharge port of the inner tank, and the discharge end of the electrically controlled valve extends out of the lower surface of the outer tank; the heat exchanger... The support bracket is fixedly installed on the top of the base platform and located on the front side of the outer tank. The discharge end of the raw material conveying system is connected to the inlet end of the filtration system. The liquid inlet and liquid outlet of the heat exchanger extend to the upper and lower ends of the gap between the inner cavity of the outer tank and the outer side of the inner tank, respectively. The feed connector is embedded in the opening on the rear top of the outer tank and is connected to the discharge pipe of the second conveying pump group. The air supply component is located on the outside of the outer tank. The mixing component is located in the inner cavity of the inner tank.

[0006] Preferably, the air supply component includes: an air supply pump, an air intake unit, an outer cylinder, a mounting plate, a first motor, a first telescopic cylinder, a second telescopic cylinder, and a third telescopic cylinder; the air supply pump is fixedly installed on the rear side of the outer surface of the outer tank via a bracket; the air intake unit is located below the air supply pump; the outer cylinder is fixedly installed in the inner cavity of the outer tank via a bracket, and is located on the upper right side of the inner cavity of the inner tank; the mounting plate is fixedly installed above the inner cavity of the outer cylinder; the first motor is fixedly installed on the upper surface of the mounting plate, and the rotating end of the first motor extends out of the lower surface of the mounting plate; the first telescopic cylinder is inserted into the inner cavity of the outer cylinder in the vertical direction, and is located below the mounting plate; the second telescopic cylinder is inserted into the inner cavity of the first telescopic cylinder in the vertical direction, and the upper part of the outer wall of the second telescopic cylinder can be engaged with the bottom of the inner wall of the first telescopic cylinder; the third telescopic cylinder is inserted into the inner cavity of the second telescopic cylinder in the vertical direction, and the upper part of the outer wall of the third telescopic cylinder can be engaged with the bottom of the inner wall of the second telescopic cylinder.

[0007] Preferably, the air supply component further includes: a folding telescopic frame, a connecting rod, a connecting seat, a lead screw assembly, an electric telescopic rod, an annular aeration pipe, and a connecting hose; the number of folding telescopic frames is two, with one end of each frame installed on the front and rear sides of the bottom center of the mounting plate; the number of connecting rods is two, with each rod installed outside the bottom axis of the front and rear folding telescopic frames, and the outer ends of each rod fixedly connected to the front and rear sides of the inner wall of the third telescopic cylinder; the connecting seat is installed inside the upper axis of the front and rear folding telescopic frames; the lead screw assembly... The lead screw of the component is fixedly installed at the bottom of the rotating end of the first motor, and the lead screw nut of the lead screw assembly is connected to the inside of the connecting seat; the electric telescopic rod is fixedly installed in the middle of the bottom end of the third telescopic cylinder in the vertical direction, and the telescopic end of the electric telescopic rod extends out of the lower surface of the third telescopic cylinder; the annular aeration pipe is arranged circumferentially below the inner cavity of the inner tank, and the annular aeration pipe is fixedly connected to the telescopic end of the electric telescopic rod through a bracket; one end of the connecting hose is connected to the exhaust port of the air supply pump, and the other end of the connecting hose extends to the inner cavity of the outer tank and is connected to the annular aeration pipe.

[0008] Preferably, the air intake unit includes: a curved fixing bracket and a three-way connector; the curved fixing bracket is fixedly installed on the lower surface of the air supply pump; the three-way connector is installed at the rear end of the curved fixing bracket, and the top exhaust pipe of the three-way connector is connected to the air intake port of the air supply pump; wherein, gas control parts are provided on both the left and right air intake ports of the three-way connector.

[0009] Preferably, the gas control section includes: an external pipe, a housing, a vertical shaft, a first sleeve, a first sector-shaped sealing plate, a second sleeve, a second sector-shaped sealing plate, a cam seat, and a transmission pin; the external pipe is installed outside the air inlet of the three-way connector; the housing is fixedly installed on the top of the outer surface of the external pipe; the vertical shaft is rotatably installed in the inner cavity of the external pipe via bearings in the vertical direction, and the top of the vertical shaft extends into the inner cavity of the housing; there are two first sleeves, which are fixedly installed at intervals on the upper and lower sides of the outer wall of the vertical shaft; the first sector-shaped sealing plate is fixedly installed on the rear side of the outer wall of the upper and lower first sleeves; there are three second sleeves, which are rotatably installed on the outer wall of the vertical shaft via bearings and are located outside the first sleeves; the second sector-shaped sealing plate is fixedly installed on the front side of the outer wall of the three second sleeves; there are two cam seats, which are fixedly installed on the top of the outer wall of the vertical shaft and the top of the outer wall of the uppermost second sleeve; there are two transmission pins, which are installed on the right side of the bottom end and the left side of the top end of the outer surface of the two cam seats.

[0010] Preferably, the gas control section further includes: a limiting groove, a movable seat, a cross-grooved seat, a micro motor, a limiting groove seat, a movable plate, a connecting rod, a radial groove, a crank, and a lever pin; the number of limiting grooves is two, and the two limiting grooves are respectively opened on the left and right sides of the inner cavity of the housing along the front-rear direction; the movable seat is inserted into the inner side of the inner cavity of the left and right limiting grooves, and the movable seat is U-shaped; the cross-grooved seat is embedded in the inner side of the movable seat, and the two drive pins are respectively inserted into the transverse grooves on the left and right sides of the inner cavity of the cross-grooved seat; the micro motor is fixedly installed on the top front side of the outer surface of the housing. The rotating end of the micro motor extends into the inner cavity of the housing; there are two limiting slots, which are respectively fixedly installed at the left and right ends of the rear top of the inner cavity of the housing; a movable plate is inserted into the inner side of the left and right limiting slots; a connecting rod is fixedly installed on the rear side of the lower surface of the movable plate, and the bottom end of the connecting rod is fixedly connected to the front side of the upper surface of the movable plate; a radial groove is formed on the front side of the movable plate; one end of the crank is fixedly installed at the bottom of the rotating end of the micro motor; a toggle pin is fixedly installed at the bottom of the other end of the crank, and the bottom of the toggle pin is inserted into the inner cavity of the radial groove.

[0011] Compared with the prior art, the beneficial effects of the present invention are: 1. Two hydrogen media with different properties are connected to the T-junction via corresponding external pipes to achieve pressure stabilization and convergence. The unified gas source after convergence enters the gas supply pump for pressurization, and then is sealed and delivered to the annular aeration pipe at the bottom of the inner tank cavity through a connecting hose. It is evenly dispersed and released into the liquid phase of the cracked gasoline in the tank through microporous aeration. When it is necessary to dynamically adjust the ratio of the two hydrogen sources, the micro motor drives the crank to rotate synchronously, causing the actuating pin at the bottom of the crank to slide back and forth along the radial groove inside the moving plate and apply a pushing force, driving the moving plate to complete precise forward and backward translation along the limiting groove seat. The moving plate drives the moving seat to move synchronously linearly under the constraint of the limiting groove through rigid transmission of the connecting rod, so that... The cross-groove seat inside the moving seat moves synchronously with it; during the sliding process of the cross-groove seat, the single horizontal linear displacement is decomposed into the opposite coaxial rotational motion of two sets of cam seats through the sliding cooperation between the internal transverse groove and the transmission pins on both sides. The two sets of cam seats drive the vertical shaft and the second sleeve to rotate synchronously, and link the first sleeve to realize the synchronous angular deflection of the first sector sealing plate and the second sector sealing plate; by controlling the translation stroke of the moving seat, the precise switching of the pipeline to full closure, full opening and any intermediate opening can be realized, dynamically changing the effective flow cross-sectional area of ​​the hydrogen pipelines on both sides, and finally completing the real-time adjustment of the mixing ratio of a section of circulating hydrogen and replenished new hydrogen, meeting the hydrogen-oil ratio matching requirements of different loads in the hydrogenation process.

[0012] 2. The first motor drives the lead screw of the lead screw assembly to rotate according to process requirements. Through the thread transmission of the lead screw nut, the connecting seat is driven to perform stable vertical lifting and lowering displacement. During the displacement process, the connecting seat synchronously drives the symmetrically arranged folding telescopic frames on both sides to switch between upward folding and downward extension. The folding telescopic frames drive the third telescopic cylinder to slide vertically along the inner cavity of the second telescopic cylinder through the synchronous transmission of the connecting rods on both sides at the bottom. Relying on the limiting and locking structure set in the third, second, and first telescopic cylinders, the multi-stage telescopic cylinders maintain a sealed state inside the cylinder while completing the step-by-step retraction or multi-stage extension stroke adjustment, effectively preventing hydrogen leakage and pressure fluctuation. At the same time, the electric telescopic rod assembled at the bottom of the third telescopic cylinder can independently complete the extension and fine adjustment action, precisely driving the annular aeration pipe to complete the vertical height fine adjustment in the inner cavity of the tank. The aeration position and aeration depth can be adjusted in real time according to the liquid level of the material in the tank and the gas-liquid mixing conditions, realizing full-area layered gas distribution and effectively improving the uniformity of oil-hydrogen gas-liquid contact.

[0013] In summary, this invention, through an adaptive dual-source independent throttling adjustment mechanism, enables the ratio control of circulating hydrogen and replenished hydrogen. It can dynamically fine-tune the flow cross-sectional area and supply flow rate of the two hydrogen media based on the unit's production load, raw material property fluctuations, and real-time hydrogenation reaction conditions. This effectively solves the industry pain points of traditional hydrogenation pretreatment systems, such as low hydrogen-to-oil ratio matching accuracy, poor adaptability to changing operating conditions, and hydrogen content imbalance. It can maintain the optimal hydrogen-to-oil ratio in the hydrogenation feed system throughout the entire process, effectively suppressing diene polymerization and gelation, and ineffective hydrogenation side reactions. This significantly improves the reaction accuracy and selectivity of the low-temperature selective hydrogenation reaction, avoids defects such as hydrogen deficiency coking and over-hydrogen saturation, and stabilizes the system. The operating parameters of the hydrogenation reaction system improve the refining quality of hydrogenated products from the source. It can also adaptively adjust the aeration height and gas distribution position in real time according to the liquid level of the material in the tank, the viscosity of the medium, and the gas-liquid mixing progress. This achieves precise microporous gas distribution with stratification, full coverage, and no dead angles, effectively solving the technical defects of traditional fixed aeration methods, such as bubble coalescence and floating, weak local gas-liquid mixing, many mixing dead angles in the tank, and poor homogenization. It expands the contact area and disturbance range of the gas and liquid phases, promotes the uniform dispersion and dissolution of micron-sized hydrogen bubbles in the liquid phase feedstock, significantly improves the homogeneous mixing effect and mixing stability of the oil and hydrogen phases, and thus comprehensively improves the operating stability of the unit and the overall process performance of hydrogenation refining. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 for Figure 1 Exploded view of the hybrid mechanism; Figure 3 for Figure 2 Exploded view of the gas supply components; Figure 4 for Figure 3 Enlarged view of point A; Figure 5 for Figure 3 Exploded view of the air intake unit; Figure 6 for Figure 5 Enlarged view of point B; Figure 7 for Figure 2 Exploded view of the mixed components; Figure 8 for Figure 7 Enlarged view of point C.

[0015] In the diagram: 1. Base platform; 2. Premixing mechanism; 21. Vertical frame; 22. Outer tank; 23. Inner tank; 24. Electrically controlled valve; 25. Heat exchanger; 26. Feed connector; 3. Air supply components; 31. Air pump; 32. Outer cylinder; 33. Mounting plate; 34. First motor; 35. First telescopic cylinder; 36. Second telescopic cylinder; 37. Third telescopic cylinder; 38. Folding telescopic frame; 39. Connecting rod; 310. Connecting seat; 311. Screw assembly; 312. Electric telescopic rod; 313. Annular aeration pipe; 314. Connecting hose; 4. Air intake unit; 41. Bent-shaped fixing frame; 42. T-joint; 43. Outer pipe; 44. Shell; 45. Vertical shaft; 46. First sleeve; 47. First sector-shaped sealing plate; 48. Second sleeve; 49. Second sector-shaped sealing plate; 410. Cam seat; 4 11. Drive pin; 412. Limiting groove; 413. Moving seat; 414. Cross groove seat; 415. Micro motor; 416. Limiting groove seat; 417. Moving plate; 418. Connecting rod; 419. Radial groove; 420. Crank; 421. Actuating pin; 5. Mixing component; 51. Rotating table; 52. Mounting seat; 53. First micro electric telescopic rod; 54. First slot frame; 55. First rack; 56. Cross; 57. First gear; 58. Mounting frame; 59. Second micro electric telescopic rod; 510. Second slot frame; 511. Second rack; 512. Second gear; 513. Second motor; 514. Stirring rod; 6. Raw material storage system; 7. Raw material conveying system; 8. Filtration system; 9. Raw material buffering system; 10. First conveying pump set; 11. Dehydration system; 12. Second conveying pump set. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Please see Figures 1-8This invention provides a technical solution: a two-stage cracked gasoline hydrorefining unit, comprising: a feedstock pretreatment unit, a first-stage low-temperature selective hydrogenation unit, an intermediate precision fractionation unit, a second-stage high-temperature deep hydrogenation unit, a product stabilization and refining unit, and a hydrogen circulation and replenishment unit connected in sequence; the first-stage low-temperature selective hydrogenation unit adopts a liquid-phase hydrogenation low-temperature condition and is loaded with a selective hydrogenation catalyst for the removal of dienes and styrene; the second-stage high-temperature deep hydrogenation unit adopts a gas-phase hydrogenation high-temperature condition and is loaded with a sulfurized hydrogenation refining catalyst for olefin saturation and heteroatom removal; the intermediate refining unit... The semi-fractionation unit is equipped with a C5 stripping tower and a C9 stripping tower, and only the C6-C8 central fraction is fed into the second-stage hydrogenation unit. The feedstock pretreatment unit includes: a base platform 1, a premixing mechanism 2, a feedstock storage system 6, a feedstock conveying system 7, a filtration system 8, a feedstock buffer system 9, a first conveying pump group 10, a dehydration system 11, and a second conveying pump group 12. The premixing mechanism 2 is located at the top left front of the base platform 1. The feedstock storage system 6 is fixedly installed at the top right front of the base platform 1, and the feedstock storage system 6 is a vertical atmospheric pressure nitrogen-sealed feedstock storage tank, with the tank body material being a pressure vessel. The tank is constructed using specialized steel plates with internal rust and anti-static treatment. The top is equipped with a nitrogen pressure stabilizing seal, a breather valve, a level transmitter, a pressure transmitter, and an explosion-proof pressure gauge. The bottom of the tank features a settling and drainage structure and a sloping sludge collection structure. It is specifically designed for storing crude cracked gasoline, a byproduct of ethylene plants. It features static settling, preliminary impurity separation, raw material pressure stabilization and buffering, air isolation to prevent oxidation and gum formation, and prevention of diene polymerization and deterioration. This allows for long-term, sealed, safe, and stable storage of crude cracked gasoline. The raw material conveying system 7 is fixedly installed on the top of the base platform 1 and located outside the raw material storage system 6. On the other side, the discharge end of the raw material storage system 6 is connected to the inlet end of the raw material conveying system 7. The raw material conveying system 7 adopts an explosion-proof variable frequency centrifugal pump conveyor unit. The whole machine is driven by an explosion-proof motor and is equipped with inlet and outlet shut-off valves, check valves, flow meters, pressure monitoring gauges, minimum flow return pipelines and variable frequency speed control systems. It can automatically adjust the conveying flow and conveying pressure according to the load of the device. It has the characteristics of stable conveying pressure, wide adjustable flow range, no pulsation of medium conveying, and adaptability to fluctuating feed conditions. It is used to continuously, smoothly and controllably convey the crude cracked gasoline inside the raw material storage system 6 to the outside.The filtration system 8 is fixedly installed at the top of the base platform 1, located on the outer left side of the raw material conveying system 7. The discharge end of the raw material conveying system 7 connects to the inlet end of the filtration system 8. The filtration system 8 adopts a fully automatic backwashing precision filter with a built-in multi-layer pleated high-precision composite filter element. The equipment is equipped with a differential pressure online monitoring transmitter, an automatic oil circuit backwashing mechanism, a PLC self-controlled flushing module, a drain valve, and an impurity collection chamber. It can monitor the inlet and outlet differential pressure in real time and has the functions of automatic backwashing when the differential pressure exceeds the standard, online self-cleaning, and filter element replacement without stopping the machine. It is specifically used to intercept coke particles, rust impurities, suspended colloids, and solid precipitates contained in crude cracked gasoline, achieving fine removal of solid phase impurities in the raw material and protecting the raw material. The downstream components and hydrogenation catalyst are not clogged or worn by hard particles. The raw material buffer system 9 is fixedly installed on the top of the base platform 1 and located on the rear side of the filter system 8. The discharge end of the filter system 8 is connected to the inlet end of the raw material buffer system 9. The raw material buffer system 9 adopts a vertical pressure-stabilizing buffer tank with a water collection bag. The top is equipped with a nitrogen pressure stabilizing interface, an explosion-proof liquid level gauge, and a pressure sensor. The bottom is equipped with an independent drain bag and an automatic drainage control valve. The tank body is equipped with flow stabilizing and rectifying components and an anti-vortex structure. It has comprehensive functions of flow buffering, pressure stabilization, material flow stabilization, trace water sedimentation and separation, and nitrogen isolation and anti-oxidation. It can effectively absorb upstream flow fluctuations and pressure pulsations, and stabilize the feeding conditions of the entire pretreatment system. Simultaneously, trace amounts of free water in the raw material continuously settle, achieving initial oil-water separation. The first conveying pump group 10 is fixedly installed at the top of the base platform 1 and located on the lower left side of the raw material buffer system 9. The discharge end of the raw material buffer system 9 is connected to the inlet end of the first conveying pump group 10. The first conveying pump group 10 adopts an explosion-proof horizontal multi-stage centrifugal pump group, equipped with an explosion-proof variable frequency motor. The sealing form adopts a double sealing structure of mechanical seal and bellows. It is equipped with inlet and outlet pressure gauges, flow monitoring instruments, shock-absorbing supports and noise reduction structures. It can perform secondary precise pressurization and stabilization of the buffered and stabilized cracked gasoline, providing stable pressure and flow conditions for the downstream dehydration system 11, ensuring controllable dehydration conditions. The dehydration system 11 is fixedly installed at the top of the base platform 1 and located on the lower left side of the raw material buffer system 9. The discharge end of the raw material buffer system 9 is connected to the inlet end of the first conveying pump group 10. The first conveying pump group 10 adopts an explosion-proof horizontal multi-stage centrifugal pump group, equipped with an explosion-proof variable frequency motor. The sealing form adopts a double sealing structure of mechanical seal and bellows. It is equipped with inlet and outlet pressure gauges, flow monitoring instruments, shock-absorbing supports and noise reduction structures. It can perform secondary precise pressurization and stabilization of the cracked gasoline after buffering and stabilization, providing stable pressure and flow conditions for the downstream dehydration system 11, ensuring controllable dehydration conditions. The system is fixedly installed at the top of the base platform 1 and located on the outer left side of the first conveying pump group 10. The discharge end of the first conveying pump group 10 is connected to the inlet end of the dehydration system 11. The dehydration system 11 adopts a high-efficiency coalescing oil-water dehydrator, which is internally equipped with a multi-stage glass fiber coalescing filter element, a rectifier distributor, a gravity sedimentation separation chamber, a water storage chamber, and an automatic drainage mechanism. It utilizes the multiple coupling principles of demulsification, coalescence, adsorption, flotation, and gravity sedimentation to deeply remove trace amounts of emulsified water from cracked gasoline. It can control the water content of the raw material within the ultra-low limit allowed by the process, and prevent trace amounts of water from entering the hydrogenation reaction system and causing problems such as catalyst hydrolysis and deactivation, increased bed pressure drop, and equipment corrosion, thereby achieving deep purification and refining of the raw material.The second delivery pump unit 12 is fixedly installed at the top of the base platform 1 and located on the front side of the dehydration system 11. The discharge end of the dehydration system 11 is connected to the inlet end of the second delivery pump unit 12. The second delivery pump unit 12 is a high-precision explosion-proof metering delivery pump unit with variable frequency precise flow control. The pump body is equipped with a high-precision flow feedback instrument, a pressure interlock protection device, and a pulsation buffer structure. It can accurately, quantitatively, and with stable pressure, deliver the clean pyrolysis gasoline after deep dehydration with low pulsation, ensuring the stability of the raw material flow, pressure, and physical properties before entering the oil-hydrogen mixing process.

[0018] As a preferred option, further, such as Figure 2As shown, the premixing mechanism 2 includes: a vertical frame 21, an outer tank 22, an inner tank 23, an electric control valve 24, a heat exchange device 25, a feed connector 26, an air supply component 3, and a mixing component 5; the vertical frame 21 is fixedly installed on the top of the base platform 1 along the vertical direction; the outer tank 22 is fixedly installed on the inner side of the vertical frame 21 along the vertical direction. The outer tank 22 is a vertical sealed jacketed protective tank, and the whole is a cylindrical vertical pressure-bearing structure, which has the basic attributes of sealing and dustproofing, heat insulation, pressure protection, and medium containment. The outer tank 22 and the inner tank 23 form an annular sealed jacket cavity, which can accommodate the circulating filling of heat exchange medium to form a surrounding full-area heat exchange insulation layer; the inner tank 23 along the vertical direction... The inner tank 23, a dedicated gas-liquid mixing reaction vessel, is fixedly installed below the inner cavity of the vertical frame 21 via a bracket. Its inner wall is mirror-polished for anti-sticking, effectively resisting the swelling and corrosion of aromatic hydrocarbons from cracked gasoline and the adhesion and scaling of trace amounts of gum. An electrically controlled valve 24 is connected to the bottom of the discharge port of the inner tank 23, with its discharge end extending beyond the lower surface of the outer tank 22. The valve 24 is an explosion-proof electric shut-off regulating valve, featuring remote electric control opening and closing, controllable flow, excellent sealing performance, and oil and corrosion resistance. It enables precise and controllable discharge of the mixed material from the inner tank 23, and has functions such as power-off self-locking, preventing backflow, and sealing off the flow. The heat exchanger 25 is fixedly installed via a bracket. At the top of the base platform 1, and located on the front side of the outer tank 22, the discharge end of the raw material conveying system 7 connects to the inlet end of the filtration system 8. The liquid inlet and outlet ends of the heat exchanger 25 extend to the upper and lower ends of the gap between the inner cavity of the outer tank 22 and the outer side of the inner tank 23, respectively. The heat exchanger 25 adopts an explosion-proof constant temperature heat transfer oil heat exchanger unit, which is a skid-mounted integrated structure. It is equipped with an intelligent temperature control module, a circulating pump, a heat exchange medium storage tank, and a temperature sensor. It can achieve precise heating, constant temperature and pressure stabilization, and closed-loop circulation of the heat exchange medium. It is suitable for a low-temperature selective hydrogenation process range. Through the gap between the outer tank and the inner tank, it achieves full-area circumferential indirect heat exchange and has high temperature control accuracy. It features a uniform temperature field, no local overheating, no media contamination, and high heat exchange efficiency, enabling stable, precise, and continuous temperature control of the oil-hydrogen mixture inside the inner tank 23. The feed connector 26 is embedded in the opening on the rear top of the outer tank 22 and is connected to the discharge pipe of the second delivery pump group 12. The feed connector 26 adopts a high-pressure explosion-proof quick-connect sealing connector, equipped with a high-pressure sealing gasket, anti-loosening locking structure, and anti-static grounding structure, which can ensure that the clean cracked gasoline delivered by the second delivery pump group 12 is introduced into the inner tank 23 without leakage, with stable pressure, and smoothly. The gas supply component 3 is located on the outside of the outer tank 22, and the mixing component 5 is located in the inner cavity of the inner tank 23.

[0019] As a preferred option, further, such as Figure 3 and Figure 4As shown, the gas supply component 3 includes: a gas supply pump 31, an air intake unit 4, an outer cylinder 32, a mounting plate 33, a first motor 34, a first telescopic cylinder 35, a second telescopic cylinder 36, a third telescopic cylinder 37, a folding telescopic frame 38, a connecting rod 39, a connecting seat 310, a lead screw assembly 311, an electric telescopic rod 312, an annular aeration pipe 313, and a connecting hose 314. The gas supply pump 31 is fixedly installed on the rear side of the outer surface of the outer tank 22 by a bracket. The gas supply pump 31 adopts an explosion-proof oil-free hydrogen booster pump, which has the characteristics of being resistant to hydrogen medium, free from oil pollution, low pulsation, and stable pressure output. It is suitable for the flammable and explosive high-purity hydrogen transportation conditions of the hydrogenation device and can perform constant pressure boosting transportation of a section of circulating hydrogen after the convergence and the replenished new hydrogen. The air intake unit 4 is located below the air supply pump 31; the outer cylinder 32 is fixedly installed in the inner cavity of the outer tank 22 by a bracket, and is located on the upper right side of the inner cavity of the inner tank 23; the mounting plate 33 is fixedly installed above the inner cavity of the outer cylinder 32; the first motor 34 is fixedly installed on the upper surface of the mounting plate 33, and the rotating end of the first motor 34 extends out of the lower surface of the mounting plate 33. The first motor 34 adopts an explosion-proof servo speed-regulating motor, which has the characteristics of precise and controllable speed, stable torque, high thrust at low speed, and smooth start and stop, and can provide high-precision rotary power input for the transmission structure of the lead screw assembly 311; the first telescopic cylinder 35 is inserted into the inner cavity of the outer cylinder 32 in the vertical direction and is located below the mounting plate 33. As a primary sealed telescopic bearing cylinder, the first telescopic cylinder 35 has a limiting sealing structure at its upper end, which can form a sliding seal with the inner wall of the outer cylinder 32. It has the structural functions of vertical sliding guidance, radial limiting, dustproof sealing, and bearing the lower cylinder. The second telescopic cylinder 36 is inserted vertically into the inner cavity of the first telescopic cylinder 35. The upper part of the outer wall of the second telescopic cylinder 36 can interlock with the bottom of the inner wall of the first telescopic cylinder 35. The second telescopic cylinder 36 is made of wear-resistant precision stainless steel tubing, and its upper outer wall has a limiting protrusion structure, which can form an axial limiting interlock with the lower end of the first telescopic cylinder 35 to prevent over-travel slippage and detachment. It has the functions of secondary vertical telescopic compensation, precise radial limiting, and step-by-step sealing protection, and can be equipped with... The first telescopic cylinder 35 and the third telescopic cylinder 37 are combined to achieve multi-stage telescopic stroke superposition; the third telescopic cylinder 37 is inserted into the inner cavity of the second telescopic cylinder 36 in the vertical direction, and the upper part of the outer wall of the third telescopic cylinder 37 can be engaged with the bottom of the inner wall of the second telescopic cylinder 36. The third telescopic cylinder 37 is a three-stage telescopic bearing cylinder at the end, and the upper and lower ends of the outer wall are provided with limiting engagement structures, which can form a limiting sliding fit with the second telescopic cylinder 36; there are two folding telescopic frames 38, and one end of the two folding telescopic frames 38 is respectively installed on the front and rear sides of the bottom middle of the mounting plate 33. The folding telescopic frame 38 is a symmetrical multi-link folding lifting transmission frame, which can convert the vertical thrust of the screw nut in the screw assembly 311 into symmetrical folding lifting motion;There are two connecting rods 39, which are respectively installed on the outside of the bottom axis of the front and rear folding telescopic frames 38. The outer ends of the front and rear connecting rods 39 are fixedly connected to the front and rear sides of the inner wall of the third telescopic cylinder 37, respectively. The connecting seat 310 is installed on the inner side of the upper axis of the front and rear folding telescopic frames 38. The screw of the screw assembly 311 is fixedly installed at the bottom of the rotating end of the first motor 34. The screw nut of the screw assembly 311 is connected to the inside of the connecting seat 310. The screw assembly 311 adopts a precision ball screw transmission assembly, which can convert the rotational motion of the first motor 34 into vertical linear displacement. The electric telescopic rod 312 is fixedly installed in the middle of the bottom end of the third telescopic cylinder 37 in the vertical direction. The telescopic end of the electric telescopic rod 312 extends out of the lower surface of the third telescopic cylinder 37. The electric telescopic rod 312 adopts an explosion-proof miniature precision electric push rod, which has the characteristics of high telescopic accuracy, strong self-locking performance, and micro-stroke adjustable, serving as the end micro The actuator allows for secondary fine-tuning of the height of the annular aeration pipe 313. The annular aeration pipe 313 is circumferentially positioned below the inner cavity of the inner tank 23. The annular aeration pipe 313 is fixedly connected to the telescopic end of the electric telescopic rod 312 via a bracket. The annular aeration pipe 313 is an annular microporous homogeneous aeration assembly with micron-level aeration micropores evenly distributed on the pipe wall. It features uniform gas output, anti-clogging, corrosion resistance, and no dead-angle gas distribution. It can evenly disperse and release high-pressure hydrogen into the liquid medium, achieving fine, comprehensive, and microbubble-type gas distribution of the gas medium. One end of the connecting hose 314 is connected to the exhaust port of the air supply pump 31, and the other end of the connecting hose 314 extends to the inner cavity of the outer tank 22 and connects to the annular aeration pipe 313. The connecting hose 314 is made of high-pressure explosion-proof and corrosion-resistant stainless steel braided hose, which can adapt to the following displacement of the annular aeration pipe 313's lifting and lowering adjustment, maintaining a sealed ventilation state throughout the process to avoid pipeline pulling and leakage, and medium leakage. ;

[0020] As a preferred option, further, such as Figure 5 and Figure 6As shown, the intake unit 4 includes: a bent fixing bracket 41 and a three-way connector 42; the bent fixing bracket 41 is fixedly installed on the lower surface of the air supply pump 31; the three-way connector 42 is installed at the rear end of the bent fixing bracket 41, and the exhaust pipe at the top of the three-way connector 42 is connected to the air inlet of the air supply pump 31. The three-way connector 42 adopts a high-pressure explosion-proof stainless steel three-way manifold valve body, which has the structural function of two-way air intake and single-way manifold output. It can realize the independent access and pressure stabilization of two gas sources, one for circulating hydrogen and the other for replenishing new hydrogen, and provide a manifold base structure for dual-way gas ratio adjustment; wherein, the air inlets on both the left and right sides of the three-way connector 42 are provided with gas control parts, which include: an external pipe 43, a housing 44, a vertical shaft 45, a first sleeve 46, and a first sector. The components include a sealing plate 47, a second sleeve 48, a second sector-shaped sealing plate 49, a cam seat 410, a transmission pin 411, a limiting groove 412, a moving seat 413, a cross groove seat 414, a micro motor 415, a limiting groove seat 416, a moving plate 417, a connecting rod 418, a radial groove 419, a crank 420, and a toggle pin 421. An external pipe 43 is installed outside the air inlet of the tee connector 42. The external pipe 43 is a high-precision, pressure-resistant inlet guide pipe, serving as an independent single-path hydrogen medium guide channel. It provides a sealed installation cavity and medium flow channel for internal components, ensuring a leak-free gas delivery process. A housing 44 is fixedly installed on the top of the outer surface of the external pipe 43. A vertical shaft 45 is rotatably mounted on the external pipe 43 via bearings in the vertical direction. The inner cavity of the housing 44 is formed by extending the top of the vertical shaft 45 into the inner cavity of the housing 44. Two first sleeves 46 are fixedly installed on the upper and lower sides of the outer wall of the vertical shaft 45 at intervals. A first sector-shaped sealing plate 47 is fixedly installed on the rear side of the outer wall of the two first sleeves 46. The first sector-shaped sealing plate 47 is made of hard alloy-coated stainless steel sheet and maintains a synchronous fixed posture with the first sleeves 46 and the vertical shaft 45. It cooperates with the rotatable second sector-shaped sealing plate 49 to form a composite throttling channel, realizing controllable adjustment of the gas flow cross-sectional area. Three second sleeves 48 are rotatably installed on the outer wall of the vertical shaft 45 via bearings, located outside the first sleeves 46. The second sector-shaped sealing plate 49... The second sector-shaped sealing plate 49, made of hard alloy corrosion-resistant sealing material, is fixedly installed on the front side of the outer wall of the three second sleeves 48. It can rotate synchronously with the second sleeve 48 and cooperate with the first sector-shaped sealing plate 47 to form an adjustable flow sealing pair, thereby realizing the adjustment of the gas passage opening. There are two cam seats 410, which are fixedly installed on the top of the outer wall of the vertical shaft 45 and the top of the outer wall of the uppermost second sleeve 48, respectively. The cam seat 410 is a special-shaped cam transmission base, which can convert the mechanical displacement of the transmission pin 411 into angular rotational motion, providing a cam transmission base for double reverse synchronous rotation adjustment. There are two transmission pins 411, which are installed on the right side of the bottom end and the left side of the top end of the outer surface of the two cam seats 410, respectively.There are two limiting grooves 412, which are respectively opened on the left and right sides of the inner cavity of the housing 44 along the front-rear direction. The limiting grooves 412 are high-precision linear guide grooves, providing a constraint track for the linear sliding motion of the moving seat 413. The moving seat 413 is inserted into the inner side of the inner cavity of the two limiting grooves 412 and is U-shaped. The cross slot seat 414 is embedded in the inner side of the moving seat 413. Two transmission pins 411 are respectively inserted into the transverse grooves on the left and right sides of the inner cavity of the cross slot seat 414. The cross slot seat 414 is a pin-groove coupling transmission component, which can form a precise sliding fit with the two sets of transmission pins 411 and has the transmission function of decomposing a single horizontal linear displacement into a bidirectional reverse rotational motion. The micro motor 415 is fixedly installed on the top front side of the outer surface of the housing 44. The rotating end of the micro motor 415 extends into the inner cavity of the housing 44. The micro motor 415 is an explosion-proof precision servo micro motor, which has the characteristics of small size, precise torque, smooth start and stop, and high angle control accuracy. The characteristics of the gas regulating structure provide precise and controllable rotary power input; there are two limiting slots 416, which are fixedly installed on the left and right ends of the rear top of the inner cavity of the housing 44, respectively. The limiting slots 416 provide stable limiting guidance for the forward and backward sliding movement of the moving plate 417; the moving plate 417 is inserted into the inner side of the left and right limiting slots 416; the connecting rod 418 is fixedly installed on the rear side of the lower surface of the moving plate 417, and the bottom end of the connecting rod 418 is connected to the moving plate. The upper surface of 413 is fixedly connected to the front side; a radial groove 419 is formed on the front side of the moving plate 417. The radial groove 419 is an arc-shaped end guide drive groove, which can form a sliding and pushing engagement with the actuating pin 421 to convert the rotary motion of the crank 420 into the linear reciprocating motion of the moving plate 417; one end of the crank 420 is fixedly installed at the bottom of the rotating end of the micro motor 415; the actuating pin 421 is fixedly installed at the bottom of the other end of the crank 420, and the bottom of the actuating pin 421 is inserted into the inner cavity of the radial groove 419.

[0021] As a preferred option, further, such as Figure 7 and Figure 8As shown, the mixing component 5 includes: a rotating platform 51, a mounting base 52, a first miniature electric telescopic rod 53, a first slot frame 54, a first rack 55, a cross 56, a first gear 57, a mounting bracket 58, a second miniature electric telescopic rod 59, a second slot frame 510, a second rack 511, a second gear 512, a second motor 513, and a stirring rod 514. The rotating platform 51 is fixedly installed in the middle of the top of the inner cavity of the outer tank 22 by a bracket. The rotating platform 51 adopts an explosion-proof precision servo rotating platform, which has the characteristics of high rotational accuracy, strong load stability, low-speed vibration-free operation, explosion-proof and corrosion-resistant properties. It can realize 360° precise circumferential angle positioning and reversing adjustment of the lower overall structure. The stirring rod 514 provides a circumferential rotation reference for full-area homogenization operation; the mounting base 52 is fixedly installed at the bottom of the rotating end of the rotating table 51; the first miniature electric telescopic rod 53 is installed on the right side of the outer surface of the mounting base 52 via a bracket in the vertical direction. The first miniature electric telescopic rod 53 adopts an explosion-proof precision miniature electric push rod, which has the characteristics of high telescopic accuracy, strong self-locking, fast response speed, and controllable stroke. The first miniature electric telescopic rod 53 serves as the linear power input source for the first-dimensional attitude adjustment, providing linear drive power for the pitch and swing adjustment of the stirring rod 514; the first slot frame 54 is installed on the lower right side of the outer surface of the mounting base 52. The first slot frame 54 adopts an integrated design. A high-precision rack guide support provides a precise constraint trajectory for the vertical telescopic sliding of the first rack 55, ensuring smooth rack meshing transmission without eccentric load. The first rack 55 is inserted into the inner cavity of the first slot bracket 54 along the vertical direction. The top of the first rack 55 is fixedly connected to the bottom of the telescopic end of the first miniature electric telescopic rod 53. The first rack 55 can accurately convert the linear telescopic displacement of the first miniature electric telescopic rod 53 into the rotational torque of the first gear 57, forming a pitch adjustment transmission pair. The cross 56 is rotatably mounted on the lower inner side of the mounting base 52 via bearings along the left and right direction. The first gear 57 is keyed to the outer right side of the cross 56's shaft. The first gear 57 and the first rack 55... 5. Engagement; Mounting bracket 58 is rotatably mounted on the lower outer side of cross 56 via bearings in the front-rear direction; the second miniature electric telescopic rod 59 is mounted on the lower left rear end of the outer surface of mounting bracket 58 via bracket. The second miniature electric telescopic rod 59 adopts an explosion-proof miniature precision drive push rod, which has the characteristics of precise micro-stroke adjustment, power failure self-locking, stable operation, and suitability for chemical explosion-proof working conditions. The second miniature electric telescopic rod 59 serves as a linear power input mechanism for second-dimensional spatial yaw adjustment; the second slot bracket 510 is mounted on the upper rear left side of the outer surface of mounting bracket 58. The second slot bracket 510 is a vertical rack guide limit support, which can limit the vertical sliding of the second rack 511 throughout its entire range;The second rack 511 is inserted vertically into the inner cavity of the second slot frame 510. The bottom end of the second rack 511 is fixedly connected to the telescopic end of the second miniature electric telescopic rod 59. The second rack 511 can stably convert the linear telescopic motion of the second miniature electric telescopic rod 59 into rotational power around the second gear 512, forming a second-dimensional yaw adjustment transmission pair. The second gear 512 is fixedly installed outside the rear shaft of the cross 56, and the outer side of the second gear 512 meshes with the second rack 511. The second motor 513 is embedded in the lower inner side of the mounting bracket 58. The second motor 513 is an explosion-proof high-speed stirring servo motor with adjustable speed, stable torque, low noise operation, and resistance to damp heat and corrosion. As the core of the self-rotation power of the stirring rod 514, it provides continuous and stable rotational power for the high-speed homogenization stirring operation of the stirring rod 514. The stirring rod 514 is fixedly installed vertically at the rotating end of the second motor 513, and the lower part of the stirring rod 514 extends into the inner cavity of the inner tank 23.

[0022] The specific work steps are as follows: Step 1: The crude pyrolysis gasoline continuously produced by the ethylene steam cracking unit is first transported to the sealed nitrogen-sealed feedstock storage tank inside the feedstock storage system 6 for pressurized storage. Through the large-volume static settling effect of the storage tank, free water, rust impurities, and heavy colloidal precipitates carried in the feedstock are pre-separated and removed. The qualified crude pyrolysis gasoline is then pressurized and transported to the filtration system 8 via the feedstock conveying system 7. The high-precision filter element inside the filtration system 8 intercepts residual solid coke powder, fine mechanical impurities, and suspended colloidal particles in the feedstock. In case of filter element clogging, the filtration system 8 can automatically start the oil washing backwashing program based on the inlet and outlet pressure difference interlock threshold, and periodically discharge concentrated filter residue to achieve long-term self-cleaning operation of the filter components. The clean liquid phase material after precision filtration flows smoothly into the buffer tank with water collection bag inside the feedstock buffer system 9. Relying on the volume effect of the buffer tank, the flow fluctuation and pressure pulsation of the feedstock from the upstream unit are effectively eliminated, ensuring the stability of the feed conditions of the downstream process. At the same time, the micro-enrichment is continuously accumulated through static settling at the bottom of the tank. The free water is measured, and the automatic liquid level interlocking mechanism is used to achieve intermittent and precise water cutting. Nitrogen gas is continuously introduced into the top of the buffer tank to form a slightly positive pressure inert protective atmosphere, which completely isolates the air from contact with the raw material and prevents the oxidation and polymerization of diene components to generate secondary gum. After buffering, stabilizing and dehydrating the material, it is pressurized and stabilized again by the first conveying pump group 10 and stably conveyed to the coalescing dehydrator inside the dehydration system 11. Through the multiple actions of demulsification, coalescence, adsorption and gravity sedimentation of the coalescing filter element, the emulsified trace water that is difficult to settle inside the raw material is removed, and the water content of the raw material is strictly controlled within the allowable limit of the hydrogenation process. This avoids the problem of water entering the reactor and causing catalyst hydrolysis and deactivation, and bed pressure drop increase. Finally, the high-cleanliness cracked gasoline that has completed all pretreatment, impurity removal, dehydration and pressure stabilization processes is pressurized again by the second conveying pump group 12 and conveyed to the feed joint 26 of the premixing mechanism 2 through the dedicated discharge pipeline. It is then introduced into the inner tank 23 through the feed joint 26 to complete the supply and storage of raw materials before oil-hydrogen mixing. Step 2: When the level of the cracked gasoline stored inside the inner tank 23 reaches the system's set working threshold, the device automatically interlocks and controls the second delivery pump group 12 to stop feeding, ensuring the stability of the liquid level inside the inner tank 23. The gas control section, symmetrically arranged on the left and right sides of the equipment, has its external pipe 43 connected to a section of circulating hydrogen return pipeline and a new hydrogen supply pipeline respectively, realizing the independent controlled gas intake of two hydrogen media with different properties. The circulating hydrogen and the new hydrogen are respectively merged into the three-way connector 42 through the external pipes 43 on both sides to complete the convergence and pressure stabilization. The combined hydrogen media enters the gas supply pump 31, which provides a stable gas supply pressure. Then, it is sealed and transported through the connecting hose 314 to the annular aeration pipe 313 at the bottom of the inner cavity of the inner tank 23. The hydrogen is evenly diffused into the liquid phase oil through the aeration micropores arranged in the annular aeration pipe 313 to achieve initial gas-liquid contact. Step 3: During the operation of Step 2, the intake ratio of the two hydrogen streams can be precisely adjusted according to the real-time hydrogen-to-oil ratio process parameters. The operator triggers the micro-motor 415 of the corresponding gas control section through the control system. The micro-motor 415 drives the crank 420 connected to the output end to rotate. During rotation, the actuating pin 421 at the bottom of the crank 420 reciprocates along the radial groove 419 inside the moving plate 417. Through the pin groove's pushing action, the moving plate 417 is driven to move forward and backward along the constraint trajectory of the limiting groove seat 416. Under the rigid connection transmission of the connecting rod 418, the moving plate 417 synchronously drives the U-shaped moving seat 413 to make a stable axial linear displacement along the limiting groove 412 inside the housing 44. The cross groove seat 414 inside the moving seat 413 moves synchronously with the moving seat. The transverse groove inside the cross groove seat 414 forms a sliding fit structure with the transmission pins 411 at the bottom and top of the two cam seats 410. During the linear displacement of the cross groove seat 414, the side wall of the groove applies a continuous and controllable lateral component force to the two sets of transmission pins 411, converting the single horizontal linear input motion into two The cam seats 410 rotate synchronously in opposite directions around a common central axis. The two cam seats 410 drive the corresponding vertical shafts 45 and the matching second sleeves 48 to rotate coaxially, and work in conjunction with the fixedly assembled first sleeve 46. This causes the first sector-shaped sealing plate 47 and the second sector-shaped sealing plate 49 to deflect synchronously at different angles. When the moving seat 413 moves to its unilateral limit position, the two sets of sector-shaped sealing plates completely adhere to the inner wall of the outer pipe 43, achieving full closure of the pipeline flow channel and completely blocking the flow of hydrogen medium in the corresponding branch. When the moving seat 413 reverses direction... When moved to the other extreme position, the sector-shaped sealing plate rotates to the fully open state parallel to the gas flow direction, and the branch pipeline is fully connected to ensure the maximum hydrogen flow supply. When the moving seat 413 stops at any intermediate stroke position, the sector-shaped sealing plate maintains the steplessly adjustable intermediate flow opening. By changing the gas flow cross-sectional area, the single-path hydrogen flow rate is precisely controlled. Relying on the coordinated adjustment of the two independent gas control parts on the left and right, the real-time dynamic matching of the mixing ratio of a section of circulating hydrogen and replenished new hydrogen is achieved, which meets the optimal hydrogen-to-oil ratio requirements of low-temperature selective hydrogenation. Step 4: During the hydrogen aeration and mixing process, the system can adaptively adjust the vertical aeration position of the annular aeration pipe 313 according to the liquid level in the inner tank 23, the oil viscosity, and the uniformity of gas-liquid mixing. Specifically, the adjustment process is as follows: The first motor 34 is energized and drives the screw of the screw assembly 311 to rotate. Through the threaded transmission between the screw nut and the screw, the rotational motion of the first motor 34 is converted into the vertical linear displacement of the connecting seat 310. During the vertical movement of the connecting seat 310, the central hinge axis of the two folding telescopic frames 38 is synchronously raised and lowered, allowing the two symmetrically arranged folding telescopic frames 38 to switch between folding upwards for storage and extending downwards as the displacement changes. The bottom of the folding telescopic frame 38 is fixedly connected to the inner wall of the third telescopic cylinder 37 through two sets of connecting rods 39, thereby... The third telescopic cylinder 37 slides vertically along the inner cavity of the second telescopic cylinder 36. At the same time, relying on the step-by-step matching limiting and locking structure of the third telescopic cylinder 37, the second telescopic cylinder 36, and the first telescopic cylinder 35, the three-stage telescopic cylinders are gradually retracted and multi-stage extended and adjusted, while maintaining the internal sealing of the cylinder throughout the process. Meanwhile, the electric telescopic rod 312, which is installed at the bottom middle of the third telescopic cylinder 37, independently performs telescopic action, further fine-tuning the vertical installation height of the annular aeration pipe 313. This ensures that the annular aeration pipe 313 can always adapt to the liquid phase depth in the tank, achieving a multi-stage gas distribution effect of low-level hydrogen dispersion aeration, uniform gas distribution in the middle layer, and high-level disturbance gas replenishment under different liquid level conditions. This expands the gas-liquid contact range, avoids local hydrogen enrichment or hydrogen deficiency dead zones, and provides stable and all-area gas phase supply conditions for homogeneous mixing of oil and liquid. Step 5: Under the synchronous working condition of continuous hydrogen aeration and dispersion, the mixing component 5 starts the stirring and homogenization operation. The second motor 513 continuously drives the bottom stirring rod 514 to rotate at high speed, continuously shearing, disturbing and mixing the oil-hydrogen mixture inside the inner tank 23, accelerating the uniform dispersion and dissolution of hydrogen bubbles in the cracked gasoline liquid phase, and quickly eliminating the gas-liquid stratification phenomenon. During the stirring operation, the top rotating platform 51 can drive the overall stirring component below to rotate circumferentially according to the mixing conditions, and adjust the basic orientation of the overall stirring structure. Step 6: For localized mixing dead zones and fluid stagnation areas within the tank, the spatial stirring angle of the stirring rod 514 can be precisely adjusted using a dual-degree-of-freedom attitude adjustment mechanism: The first micro electric telescopic rod 53 drives the first rack 55 to slide vertically along the inner cavity of the first slot frame 54 through its telescopic movement. Utilizing the gear-rack meshing transmission relationship between the first rack 55 and the first gear 57, the first gear 57 and the coaxially fixed cross 56 are driven to complete the first-dimensional pitch swing around the hinge axis inside the mounting base 52, thereby adjusting the vertical tilt angle of the stirring rod 514. The second micro electric telescopic rod 59, through its own telescopic stroke change, drives the second rack 511 to slide vertically along the inner cavity of the second slot frame 510. The meshing transmission of gear 511 and the second gear 512 drives the mounting frame 58 to complete the second-dimensional horizontal yaw motion around the outer axis of the cross 56. By individually controlling or coordinating the extension stroke of the two sets of micro electric telescopic rods, the two sets of independent linear extension displacements are coupled and superimposed through multi-stage transmission pairs, and finally transformed into the pitch and yaw two-degree-of-freedom spherical rotation motion of the stirring rod 514, realizing the adjustment of the spatial attitude of the stirring rod 514. It can be used to target and strengthen the stirring of fluids in different areas and at different depths in the tank, eliminating the defects of traditional fixed stirring mode such as mixing dead angles, poor homogenization effect, and bubble coalescence and floating, and maximizing the gas-liquid mixing uniformity of the first-stage circulating hydrogen, the replenished new hydrogen and the cracked gasoline. Step 7: Under the simultaneous operation of hydrogen aeration and gas-liquid homogenization inside the inner tank 23, the heat exchanger 25 can heat its built-in heat transfer medium at a constant temperature according to the preset feed temperature parameters of a low-temperature selective hydrogenation stage. After the heat transfer medium is heated to the specified temperature range, it is transported through the medium circulation pipeline of the heat exchanger 25 to the annular interlayer gap cavity formed between the outer tank 22 and the inner tank 23. The interlayer surrounding full-area heat exchange structure is used to heat the material inside the inner tank 23. After the oil-hydrogen mixing process inside the inner tank 23 is completed, the internal structure of the automatic control gas supply component 3 is reset to zero and the hydrogen supply passage is closed. At the same time, the mixing component 5 stops and resets to the initial standby position. The system automatically opens the electronic control valve 24, so that the oil-hydrogen mixture prepared inside the inner tank 23 is discharged through the bottom outlet and continuously transported to the subsequent low-temperature selective hydrogenation process, providing a stable and high-quality hydrogenation feed for the two-stage cracked gasoline hydrorefining unit.

[0023] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A two-stage cracked gasoline hydrorefining unit, characterized in that, include: The raw material pretreatment unit, the first low-temperature selective hydrogenation unit, the intermediate precision fractionation unit, the second high-temperature deep hydrogenation unit, the product stabilization and refining unit, and the hydrogen circulation and replenishment unit are connected in sequence. The first-stage low-temperature selective hydrogenation unit adopts a liquid-phase hydrogenation low-temperature operating condition and is filled with a selective hydrogenation catalyst for the removal of dienes and styrene; the second-stage high-temperature deep hydrogenation unit adopts a gas-phase hydrogenation high-temperature operating condition and is filled with a sulfurized hydrogenation refining catalyst for olefin saturation and heteroatom removal; the intermediate precision fractionation unit is equipped with a C5 removal tower and a C9 removal tower, and only the C6-C8 central fraction is fed into the second-stage hydrogenation unit; The raw material pretreatment unit includes: Base platform (1); The premixing mechanism (2) is located at the top left front of the base platform (1); The raw material storage system (6) is fixedly installed at the top right front of the base platform (1); The raw material conveying system (7) is fixedly installed on the top of the base platform (1) and located on the front side of the raw material storage system (6). The discharge end of the raw material storage system (6) is connected to the inlet end of the raw material conveying system (7). The filtration system (8) is fixedly installed at the top of the base platform (1) and located on the outside left side of the raw material conveying system (7). The discharge end of the raw material conveying system (7) is connected to the inlet end of the filtration system (8). The raw material buffer system (9) is fixedly installed on the top of the base platform (1) and located on the rear side of the filter system (8). The discharge end of the filter system (8) is connected to the feed end of the raw material buffer system (9).

2. The two-stage cracked gasoline hydrorefining unit according to claim 1, characterized in that, The raw material pretreatment unit further includes: The first conveying pump group (10) is fixedly installed at the top of the base platform (1) and located on the lower left side of the raw material buffer system (9). The discharge end of the raw material buffer system (9) is connected to the inlet end of the first conveying pump group (10). The dewatering system (11) is fixedly installed at the top of the base platform (1) and located on the outside left side of the first conveying pump group (10). The discharge end of the first conveying pump group (10) is connected to the feed end of the dewatering system (11). The second conveying pump group (12) is fixedly installed at the top of the base platform (1) and located on the front side of the dewatering system (11). The discharge end of the dewatering system (11) is connected to the feed end of the second conveying pump group (12).

3. A two-stage cracked gasoline hydrorefining apparatus according to claim 2, characterized in that, The premixing mechanism (2) includes: A vertical frame (21) is fixedly installed on the top of the base platform (1) in the vertical direction; The outer tank (22) is fixedly installed on the inner side of the vertical frame (21) in the vertical direction; The inner tank (23) is fixedly installed in the lower part of the inner cavity of the vertical frame (21) by a bracket along the vertical direction; An electric control valve (24) is connected and installed at the bottom of the discharge port of the inner tank (23), and the discharge end of the electric control valve (24) extends out of the lower surface of the outer tank (22); The heat exchanger (25) is fixedly installed on the top of the base platform (1) by a bracket and is located on the front side of the outer tank (22). The discharge end of the raw material conveying system (7) is connected to the inlet end of the filtration system (8). The liquid inlet and liquid outlet of the heat exchanger (25) extend to the upper and lower ends of the inner cavity of the outer tank (22) and the outer gap of the inner tank tank (23), respectively. The feed connector (26) is embedded in the top rear opening of the outer tank (22) and is connected to the discharge pipe of the second conveying pump group (12).

4. A two-stage cracked gasoline hydrorefining apparatus according to claim 3, characterized in that, The premixing mechanism (2) further includes: An air supply component (3) is disposed outside the external tank (22); A mixing component (5) is disposed in the inner cavity of the inner tank (23).

5. A two-stage cracked gasoline hydrorefining apparatus according to claim 4, characterized in that, The gas supply component (3) includes: An air supply pump (31) is fixedly installed on the rear side of the outer surface of the outer tank (22) by a bracket; An air intake unit (4) is located below the air supply pump (31); The outer cylinder (32) is fixedly installed in the inner cavity of the outer tank (22) by a bracket and is located on the upper right side of the inner liner tank (23); Mounting plate (33) is fixedly installed above the inner cavity of the outer cylinder (32); The first motor (34) is fixedly installed on the upper surface of the mounting plate (33), and the rotating end of the first motor (34) extends out of the lower surface of the mounting plate (33); The first telescopic cylinder (35) is inserted into the inner cavity of the outer cylinder (32) in the vertical direction and is located below the mounting plate (33); The second telescopic cylinder (36) is inserted into the inner cavity of the first telescopic cylinder (35) in the vertical direction, and the upper part of the outer wall of the second telescopic cylinder (36) can be engaged with the bottom of the inner wall of the first telescopic cylinder (35). The third telescopic cylinder (37) is inserted into the inner cavity of the second telescopic cylinder (36) in the vertical direction, and the upper part of the outer wall of the third telescopic cylinder (37) can be engaged with the bottom of the inner wall of the second telescopic cylinder (36).

6. A two-stage cracked gasoline hydrorefining apparatus according to claim 5, characterized in that, The gas supply component (3) also includes: Folding telescopic frame (38), the number of the folding telescopic frame (38) is two, and one end of the two folding telescopic frames (38) is respectively installed on the front and rear sides of the bottom middle of the mounting plate (33); Connecting rod (39), there are two connecting rods (39), the two connecting rods (39) are respectively installed outside the bottom axis of the front and rear folding telescopic frames (38), and the outer ends of the front and rear connecting rods (39) are respectively fixedly connected to the front and rear sides of the inner wall of the third telescopic cylinder (37); The connecting seat (310) is installed on the inner side of the upper axis of the two folding telescopic frames (38) at the front and rear; The lead screw assembly (311) has its lead screw fixedly installed at the bottom of the rotating end of the first motor (34), and the lead screw nut of the lead screw assembly (311) is connected to the interior of the connecting seat (310). An electric telescopic rod (312) is fixedly installed in the middle of the bottom end of the third telescopic cylinder (37) in the vertical direction, and the telescopic end of the electric telescopic rod (312) extends out of the lower surface of the third telescopic cylinder (37). An annular aeration pipe (313) is arranged circumferentially below the inner cavity of the inner tank (23), and the annular aeration pipe (313) is fixedly connected to the telescopic end of the electric telescopic rod (312) by a bracket. A connecting hose (314) is connected at one end to the exhaust port of the air supply pump (31), and the other end of the connecting hose (314) extends into the inner cavity of the outer tank (22) and is connected to the annular aeration pipe (313).

7. A two-stage cracked gasoline hydrorefining apparatus according to claim 6, characterized in that, The intake unit (4) includes: A curved fixing bracket (41) is fixedly installed on the lower surface of the air supply pump (31); A three-way connector (42) is installed at the rear end of the curved fixing bracket (41), and the top exhaust pipe of the three-way connector (42) is connected to the air inlet of the air supply pump (31). The three-way connector (42) has gas control components installed on both the left and right air inlets.

8. A two-stage cracked gasoline hydrorefining apparatus according to claim 7, characterized in that, The gas control section includes: An external pipe (43) is installed outside the air inlet of the three-way connector (42); The housing (44) is fixedly installed on the top of the outer surface of the outer tube (43); A vertical shaft (45) is rotatably mounted in the inner cavity of the outer tube (43) via a bearing in the up-down direction, and the top of the shaft of the vertical shaft (45) extends into the inner cavity of the housing (44); The first sleeve (46) has two sleeves (46), and the two first sleeves (46) are fixedly installed on the upper and lower sides of the outer wall of the vertical shaft (45) at intervals. The first sector-shaped sealing plate (47) is fixedly installed on the rear side of the outer wall of the upper and lower first sleeves (46); The second sleeve (48) has three parts. The three second sleeves (48) are rotatably mounted on the outer wall of the vertical shaft (45) by bearings and are located outside the first sleeve (46). The second sector-shaped sealing plate (49) is fixedly installed on the front side of the outer wall of the three second sleeves (48); Cam seat (410), there are two cam seats (410), and the two cam seats (410) are respectively fixedly installed on the top of the outer wall of the vertical shaft (45) and the top of the outer wall of the uppermost second sleeve (48); The transmission pin (411) is two in number, and the two transmission pins (411) are respectively installed on the bottom right and top left of the outer surface of the two cam seats (410).

9. A two-stage cracked gasoline hydrorefining apparatus according to claim 8, characterized in that, The gas control section also includes: The limiting groove (412) is two in number, and the two limiting grooves (412) are respectively opened on the left and right sides of the inner cavity of the shell (44) along the front and rear directions; The movable seat (413) is inserted into the inner cavity of the left and right limiting grooves (412), and the movable seat (413) is U-shaped. The cross-groove seat (414) is embedded in the inner side of the movable seat (413), and the two transmission pins (411) are respectively inserted into the transverse grooves on the left and right sides of the inner cavity of the cross-groove seat (414). A micro motor (415) is fixedly installed on the top front side of the outer surface of the housing (44), and the rotating end of the micro motor (415) extends into the inner cavity of the housing (44); The limiting slot (416) has two positions, and the two limiting slots (416) are respectively fixedly installed on the left and right ends of the rear end of the inner cavity of the housing (44). The movable plate (417) is inserted into the inner side of the two limiting slots (416) on the left and right sides; A connecting rod (418) is fixedly installed on the rear side of the lower surface of the movable plate (417), and the bottom end of the connecting rod (418) is fixedly connected to the front side of the upper surface of the movable seat (413). A radial groove (419) is formed on the front side of the movable plate (417); A crank (420) is fixedly mounted at one end to the bottom of the rotating end of the micro motor (415); A toggle pin (421) is fixedly installed at the bottom of the other end of the crank (420), and the bottom of the toggle pin (421) is inserted into the inner cavity of the radial groove (419).

Images