A high-boiling aromatic hydrocarbon solvent extractive distillation coupling refining equipment

Abstract

The application discloses a high-boiling aromatic hydrocarbon solvent extraction rectification coupling refining equipment and belongs to the technical field of chemical equipment. The equipment comprises an extraction rectification tower, a condenser and a reflux tank are arranged at the top of the extraction rectification tower, a reboiler is arranged at the bottom of the extraction rectification tower, and the extraction rectification tower further comprises a solvent cylinder and a raw material cylinder. The two solvent cylinders are symmetrically arranged at the two sides of the top end of the extraction rectification tower. The raw material cylinder is symmetrically arranged at the vertical opposite position below the solvent cylinders. The first pistons driven by the first piston rods are slidably arranged in the solvent cylinders and the raw material cylinder. The reciprocating mechanism composed of the driving motor, the driving bevel gear, the driven bevel gear, the first shaft rod, the cross rod, the shifting rod, the rectangular frame plate, the strip-shaped groove, the sliding block and the screw rod can realize the synchronous and quantitative suction and discharge of the solvent and the raw material, avoids the measurement error superposition and accumulation problems caused by the independent monitoring of the traditional double-path flow meters, and ensures the accuracy and stability of the solvent ratio.

Description

Technical Field

[0001] This invention relates to an extraction distillation coupled refining device, and more particularly to an extraction distillation coupled refining device for high-boiling-point aromatic hydrocarbon solvents, belonging to the field of chemical equipment technology. Background Technology

[0002] In the extraction and distillation coupled refining process of high-boiling-point aromatic solvents, the extraction distillation column is the core equipment for achieving efficient separation of aromatics and non-aromatics. The solvent ratio and reflux ratio are the two most critical operating parameters affecting the separation effect and product quality. The solvent ratio directly determines the selective dissolution ability of the extractant to aromatics, while the reflux ratio directly affects the gas-liquid mass transfer efficiency and product purity in the column.

[0003] In existing extractive distillation equipment, the solvent ratio and reflux ratio control both rely on independent monitoring by flow meters. The former causes the solvent ratio to deviate due to the superposition of errors from the two flow meters, while the latter causes fluctuations due to the separate measurement of reflux flow and output flow and the lag adjustment of the controller. The entire control system is complex, with insufficient control accuracy and stability, which directly affects the quality of the finished product.

[0004] To address these issues, a high-boiling-point aromatic hydrocarbon solvent extraction and distillation coupled purification device was designed. Summary of the Invention

[0005] The main objective of this invention is to provide a solvent extraction and distillation coupled purification apparatus for high-boiling-point aromatic hydrocarbons to solve the problems mentioned in the background art.

[0006] The objective of this invention can be achieved by adopting the following technical solution: A solvent extraction and distillation coupled purification apparatus for high-boiling-point aromatic hydrocarbons includes an extractive distillation column, a condenser and a reflux tank at the top of the column, and a reboiler at the bottom of the column. It also includes: The solvent cylinder and the raw material cylinder are provided. There are two solvent cylinders, which are symmetrically arranged on both sides of the top of the extractive distillation column. There are two raw material cylinders, which are symmetrically arranged on both sides of the extractive distillation column and located below the solvent cylinders. The raw material cylinder and the solvent cylinder are arranged vertically opposite each other. The first piston is slidably disposed inside the solvent cylinder and the raw material cylinder; The first piston rod is fixedly connected to the outer end of the first piston and extends out of the solvent cylinder and the raw material cylinder; A reciprocating mechanism is located on the side of the extractive distillation column and is used to drive the first piston rod to reciprocate. The reflux tank and the discharge tank are located on the side of the extractive distillation column and are connected to the liquid outlet of the reflux tank. The internal volume of the reflux tank and the discharge tank is set according to the reflux ratio. The second piston is slidably disposed inside the return liquid cylinder and the discharge cylinder; The second piston rod is fixedly connected to the outer end of the second piston and extends out of the outside of the return liquid cylinder and the discharge cylinder; A telescopic mechanism, connected between the second piston rods, is used to synchronously drive the second piston in the return liquid cylinder and the discharge cylinder to slide. The telescopic mechanism and the reciprocating mechanism are mechanically linked, with the reciprocating mechanism providing power for synchronous operation.

[0007] Preferably, the reciprocating mechanism includes a drive motor, a driving bevel gear, a driven bevel gear, a first shaft, a crossbar, a lever, a rectangular frame plate, and a translation assembly; The drive motor is fixedly installed on the outer wall of the extraction distillation column. The driving bevel gear is installed at the output end of the drive motor. The driven bevel gear is symmetrically meshed on the upper and lower sides of the driving bevel gear. The first shaft is coaxially fixed on the side of the driven bevel gear away from the driving bevel gear. The crossbar is fixedly installed on the first shaft. A lever is vertically installed on the outside of the crossbar. The rectangular frame plate is fixedly installed between the two sets of first piston rods on the same plane. The lever passes through the rectangular frame plate and is slidably connected to it. The crossbar is equipped with a translation component for fine-tuning the position of the lever to control the sliding amplitude of the first piston.

[0008] This reciprocating mechanism can efficiently convert the rotational motion of the drive motor into the reciprocating linear motion of the first piston rod, and enable convenient adjustment of the piston stroke, ensuring the synchronization and proportional accuracy of solvent and raw material delivery.

[0009] Preferably, the translation component includes a strip groove, a slider, and a screw; A strip groove is formed on the crossbar, and a slider is slidably set in the strip groove. One end of the lever is rotatably connected to the slider, and a screw is rotatably installed in the strip groove and threadedly connected to the slider.

[0010] The translation component, which combines a screw and a slider, allows for precise and stepless adjustment of the rotation radius of the lever, thereby enabling continuous adjustment of the solvent ratio and improving the equipment's adaptability to different operating conditions.

[0011] Preferably, one end of the screw extends to the outside of the crossbar, and an adjustment groove is provided at the end of the screw.

[0012] The screw end is extended and an adjustment groove is provided, which allows operators to quickly adjust it without disassembling the external structure, simplifying maintenance and parameter adjustment operations.

[0013] Preferably, the telescopic mechanism includes a fixed plate, a connecting rod, a second shaft, and an arm. The fixing plate is fixedly installed at the ends of the two sets of second piston rods. The second shaft is coaxially fixed to the side of the driving bevel gear. An arm is fixedly installed at the end of the second shaft away from the driving bevel gear. A connecting rod is hinged between the end of the arm and the fixing plate.

[0014] This telescopic mechanism enables the synchronous driving of the second piston in the reflux cylinder and the discharge cylinder using the same drive source, ensuring precise timing matching between the reflux and extraction actions, without requiring additional power.

[0015] Preferably, the input end of the reflux cylinder and the discharge cylinder are connected to the liquid outlet end of the reflux tank by a reflux main pipe, the output end of the reflux cylinder is connected to a conduit, the end of the conduit away from the reflux cylinder is provided with a temporary storage tank that is connected to the reflux port at the top of the extractive distillation column, the output end of the discharge cylinder is provided with a discharge pipe, and a one-way valve is connected in series on the reflux main pipe, the conduit and the discharge pipe.

[0016] By setting up a reflux main pipe and a check valve, the liquid can flow in one direction, preventing backflow and further improving the reliability of reflux ratio control.

[0017] Preferably, a solvent inlet pipe is connected between the input ends of the two sets of solvent cylinders, and a solvent outlet pipe is provided between the output ends of the two sets of solvent cylinders, which is connected to the solvent port at the top of the extractive distillation column. Both the solvent inlet pipe and the solvent outlet pipe are equipped with a one-way valve.

[0018] The solvent cylinders are arranged symmetrically, and the corresponding inlet and outlet pipes and check valves enable continuous and stable delivery of solvent. The delivery volume is precisely controlled by the piston stroke, which improves the metering accuracy.

[0019] Preferably, a raw material inlet pipe is connected between the input ends of the two sets of raw material cylinders, and a raw material outlet pipe is provided between the output ends of the two sets of raw material cylinders, which is connected to the raw material inlet on the side of the extractive distillation column. Both the raw material inlet pipe and the raw material outlet pipe are equipped with one-way valves.

[0020] By using symmetrically arranged raw material cylinders, inlet and outlet pipes, and check valves, the raw materials are synchronously and quantitatively conveyed, maintaining a fixed ratio with the solvent delivery, thus eliminating flow meter errors from a mechanical structure perspective.

[0021] Preferably, the inner diameter of the reflux cylinder and the discharge cylinder and the reciprocating stroke of the second piston are matched so that the ratio of their effective working volumes is equal to the preset reflux ratio.

[0022] By matching the cylinder inner diameter with the piston stroke, the ratio of the effective working volume is made equal to the preset reflux ratio. This allows for constant control of the reflux ratio without the need for sensors and regulating valves, ensuring product purity.

[0023] Preferably, the outer diameter of the lever is adapted to the inner side of the rectangular frame plate, and both the outer wall of the lever and the inner side of the rectangular frame plate are coated with a wear-resistant coating.

[0024] By applying a wear-resistant coating to the mating surface between the lever and the rectangular frame plate, wear can be significantly reduced, the service life of the mechanism can be extended, and the frequency of maintenance can be reduced.

[0025] The beneficial effects of this invention are as follows: This invention provides a high-boiling-point aromatic hydrocarbon solvent extraction and distillation coupled refining device. Solvent cylinders are symmetrically arranged on both sides of the top of the extraction and distillation column, and raw material cylinders are symmetrically arranged vertically below them. Both the solvent and raw material cylinders contain a first piston driven by a first piston rod. This, combined with a reciprocating mechanism consisting of a drive motor, a driving bevel gear, a driven bevel gear, a first shaft, a crossbar, a lever, a rectangular frame, a strip groove, a slider, and a screw, enables synchronous quantitative intake and discharge of solvent and raw material. This avoids the problem of cumulative measurement errors caused by independent monitoring with traditional dual-channel flow meters, ensuring the accuracy and stability of the solvent ratio. Furthermore, by adjusting the position of the lever within the reciprocating mechanism, the sliding amplitude of the first piston can be easily changed, thereby achieving stepless adjustment of the solvent ratio. This allows the device to flexibly adapt to different raw material compositions and process requirements, significantly improving the applicability and operational flexibility of the device. By installing a reflux cylinder and a discharge cylinder on the side of the extractive distillation column, with the internal volumes of the reflux cylinder and discharge cylinder set according to the reflux ratio, and utilizing a telescopic mechanism consisting of a fixed plate, connecting rod, second shaft, and arm to synchronously control the sliding of the second piston in the reflux cylinder and discharge cylinder, quantitative synchronous delivery of reflux liquid and produced liquid is achieved. This replaces the traditional closed-loop regulation method of flow meter and flow controller, eliminating reflux ratio fluctuations caused by flow meter accuracy deviation and nonlinearity of regulating valve, ensuring accurate and constant reflux ratio. At the same time, the mechanical linkage between the telescopic mechanism and the reciprocating mechanism enables the control of reflux ratio and solvent ratio to work in tandem, eliminating the need for a complex electronic control system, thus improving the reliability of equipment operation and reducing manufacturing costs. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a partial structural diagram of the top of the extractive distillation column of the present invention; Figure 3 This is a schematic diagram of the structure between the first piston rods of the present invention; Figure 4 This is a schematic diagram of the reciprocating mechanism and the first piston rod in the linkage state of the present invention; Figure 5 This is a schematic diagram of the top structure of the crossbar of the present invention; Figure 6 This is a schematic cross-sectional view of the solvent tank and raw material tank of the present invention; Figure 7 This is a schematic diagram of the linkage state between the telescopic mechanism and the reciprocating mechanism of the present invention; Figure 8 This is a schematic diagram of the linkage state between the telescopic mechanism and the second piston rod of the present invention; Figure 9 This is a schematic cross-sectional view of the inside of the reflux cylinder and discharge cylinder of the present invention.

[0027] In the diagram: 1. Extractive distillation column; 101. Condenser; 102. Reflux tank; 103. Reboiler; 2. Solvent tank; 201. Solvent inlet pipe; 202. Solvent outlet pipe; 3. Raw material cylinder; 301. Raw material inlet pipe; 302. Raw material outlet pipe; 4. First piston; 5. First piston rod; 6. Reciprocating mechanism; 601. Drive motor; 602. Driving bevel gear; 603. Driven bevel gear; 604. First shaft; 605. Crossbar; 606. Lever; 607. Rectangular frame plate; 608. Strip groove; 609. Slider; 610. Screw; 7. Reflux cylinder; 701. Guide tube; 8. Discharge cylinder; 801. Discharge pipe; 9. Second piston; 10. Second piston rod; 11. Telescopic mechanism; 1101. Fixing plate; 1102. Connecting rod; 1103. Second shaft; 1104. Arm; 12. Temporary storage tank; 13. Return main pipe. Detailed Implementation

[0028] To enable those skilled in the art to better 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.

[0029] Example 1: As Figures 1-9 As shown, this embodiment provides a high-boiling-point aromatic hydrocarbon solvent extraction and distillation coupled purification apparatus, including an extraction distillation column 1, a condenser 101 and a reflux tank 102 at the top of the extraction distillation column 1, and a reboiler 103 at the bottom of the column, and further including: Solvent cylinder 2 and raw material cylinder 3 are provided. There are two solvent cylinders 2, which are symmetrically arranged on both sides of the top of the extractive distillation column 1. There are two raw material cylinders 3, which are symmetrically arranged on both sides of the extractive distillation column 1 and located below the solvent cylinders 2. The raw material cylinders 3 and solvent cylinders 2 are arranged vertically opposite each other. The first piston 4 is slidably disposed inside the solvent cylinder 2 and the raw material cylinder 3; The first piston rod 5 is fixedly connected to the outer end of the first piston 4 and extends out of the solvent cylinder 2 and the raw material cylinder 3; The reciprocating mechanism 6 is located on the side of the extractive distillation column 1 and is used to drive the first piston rod 5 to reciprocate. The reflux cylinder 7 and the discharge cylinder 8 are located on the side of the extractive distillation column 1 and are connected to the liquid outlet of the reflux tank 102. The internal volumes of the reflux cylinder 7 and the discharge cylinder 8 are set according to the reflux ratio. The second piston 9 is slidably disposed inside the return liquid cylinder 7 and the discharge cylinder 8; The second piston rod 10 is fixedly connected to the outer end of the second piston 9 and extends out of the outside of the return liquid cylinder 7 and the discharge cylinder 8; The telescopic mechanism 11 is connected between the second piston rods 10 and is used to synchronously drive the second piston 9 in the return liquid cylinder 7 and the discharge cylinder 8 to slide. The telescopic mechanism 11 is mechanically linked to the reciprocating mechanism 6, and the reciprocating mechanism 6 provides power for synchronous operation.

[0030] When the equipment is running, the reciprocating mechanism 6 outputs reciprocating linear power, which synchronously drives all the first piston rods 5 to move. The first piston rods 5 push the first piston 4 to slide back and forth inside the solvent cylinder 2 and the raw material cylinder 3. Through the suction and pressure action of the piston, the suction and discharge of the extraction solvent and the raw material are completed respectively. Since the solvent cylinder 2 and the raw material cylinder 3 are driven synchronously by the same reciprocating mechanism 6, the liquid volume ratio of each cylinder is constant, which ensures the accuracy and stability of the solvent ratio from the mechanical structure level, replacing the detection and control method of the traditional dual flow meter.

[0031] At the same time, the telescopic mechanism 11 and the reciprocating mechanism 6 operate synchronously in mechanical linkage, driving the two sets of second piston rods 10 to move synchronously. The second piston rods 10 push the second pistons 9 to slide back and forth in the reflux cylinder 7 and the discharge cylinder 8 respectively. The effective working volume of the reflux cylinder 7 and the discharge cylinder 8 is configured according to the preset reflux ratio. Therefore, the amount of reflux liquid and produced liquid transported in a single cycle always maintains a fixed ratio, realizing constant control of the reflux ratio.

[0032] Solvent and raw material are continuously and quantitatively fed into extractive distillation column 1 for extractive distillation separation. The gas phase at the top of the column is condensed by condenser 101 and enters reflux tank 102. It is then divided into reflux liquid and product liquid according to a fixed reflux ratio. The liquid phase at the bottom of the column is heated and circulated by reboiler 103, and finally the coupled purification process of high-boiling-point aromatic solvent is completed.

[0033] Example 2: The solution in Example 1 will be further described below with reference to its specific working method. See the description below for details: In this embodiment, the reciprocating mechanism 6 includes a drive motor 601, a driving bevel gear 602, a driven bevel gear 603, a first shaft 604, a crossbar 605, a lever 606, a rectangular frame plate 607, and a translation assembly; The drive motor 601 is fixedly installed on the outer wall of the extraction distillation column 1. The driving bevel gear 602 is installed at the output end of the drive motor 601. The driven bevel gear 603 is symmetrically meshed on the upper and lower sides of the driving bevel gear 602. The first shaft 604 is coaxially fixed on the side of the driven bevel gear 603 away from the driving bevel gear 602. The crossbar 605 is fixedly installed on the first shaft 604. A lever 606 is vertically installed on the outer side of the crossbar 605. The rectangular frame plate 607 is fixedly installed between the two sets of first piston rods 5 on the same plane. The lever 606 passes through the rectangular frame plate 607 and is slidably connected to it. The crossbar 605 is provided with a translation component for fine-tuning the position of the lever 606 to control the sliding amplitude of the first piston 4.

[0034] After the drive motor 601 starts, it outputs rotational power, driving the active bevel gear 602 to rotate synchronously. The active bevel gear 602 meshes with and drives two sets of driven bevel gears 603 arranged symmetrically to rotate synchronously in opposite directions. The driven bevel gears 603 drive the coaxial first shaft 604 to rotate synchronously. When the first shaft 604 rotates, it drives the crossbar 605 to swing around the axis of the first shaft 604. The lever 606 on the crossbar 605 moves synchronously with the crossbar 605. At the same time, the lever 606 is embedded in the frame of the rectangular frame plate 607 and slides along the inner wall of the frame, converting the circular motion into the horizontal reciprocating linear motion of the rectangular frame plate 607. The rectangular frame plate 607 is fixedly connected to two sets of first piston rods 5 on the same plane, thereby driving the upper and lower sets of first piston rods 5 to slide synchronously back and forth, respectively driving the first pistons 4 in the solvent cylinder 2 and the raw material cylinder 3 to synchronously complete the liquid suction and discharge actions, realizing the synchronous quantitative delivery of solvent and raw materials.

[0035] In this embodiment, the translation component includes a strip groove 608, a slider 609, and a screw 610; A strip groove 608 is formed on a crossbar 605, a slider 609 is slidably disposed in the strip groove 608, one end of a lever 606 is rotatably connected to the slider 609, and a screw 610 is rotatably installed in the strip groove 608 and threadedly connected to the slider 609.

[0036] When the solvent ratio needs to be adjusted, the screw 610 is rotated. The screw 610 drives the slider 609 to slide along the length of the strip groove 608 through the threaded transmission, which in turn drives the lever 606 to move radially along the crossbar 605. After the position of the lever 606 changes, its radius of rotation for circular motion changes accordingly, which in turn changes the reciprocating linear stroke of the rectangular frame plate 607, and finally adjusts the sliding amplitude of the first piston 4 in the solvent cylinder 2 and the raw material cylinder 3, thereby changing the volume of liquid sucked and discharged in a single cycle. By adjusting the screw 610, the piston stroke can be infinitely adjusted, thereby flexibly changing the delivery ratio of solvent and raw materials to adapt to the production needs of different raw material compositions and process parameters.

[0037] In this embodiment, one end of the screw 610 extends to the outside of the crossbar 605, and an adjustment groove is provided at the end of the screw 610.

[0038] The outer end of the screw 610 extends to the outside of the crossbar 605. The operator can directly rotate the screw 610 through the adjustment groove at the end with a standard tool. The position of the lever 606 can be adjusted without disassembling the external structure of the reciprocating mechanism 6. This facilitates quick adjustment of the solvent ratio parameters during the equipment installation and commissioning stage and when production conditions change.

[0039] In this embodiment, the telescopic mechanism 11 includes a fixed plate 1101, a connecting rod 1102, a second shaft 1103, and an arm 1104; The fixing plate 1101 is fixedly installed at the ends of the two sets of second piston rods 10. The second shaft 1103 is coaxially fixed on the side of the active bevel gear 602. An arm 1104 is fixedly installed at the end of the second shaft 1103 away from the active bevel gear 602. A connecting rod 1102 is hinged between the end of the arm 1104 and the fixing plate 1101.

[0040] The second shaft 1103 is coaxially and fixedly connected to the active bevel gear 602, and rotates synchronously with the active bevel gear 602, thereby driving the arm 1104 to swing around the axis of the second shaft 1103 in a circular motion. When the arm 1104 swings, it pushes and pulls the fixed plate 1101 in a horizontal reciprocating linear motion through the hinged connecting rod 1102. The fixed plate 1101 synchronously drives the two sets of second piston rods 10 to slide back and forth, driving the second pistons 9 in the reflux cylinder 7 and the discharge cylinder 8 to synchronously complete the liquid suction and discharge actions. Since the telescopic mechanism 11 is directly powered by the active bevel gear 602 of the reciprocating mechanism 6, the two are completely mechanically linked, and the timing of the solvent feeding and reflux extraction actions is precisely matched. There is no need to set up an additional electrical control synchronization system, and the operation reliability is higher.

[0041] In this embodiment, the input ends of the reflux cylinder 7 and the discharge cylinder 8 are connected to the liquid outlet end of the reflux tank 102 via a reflux main pipe 13. The output end of the reflux cylinder 7 is connected to a conduit 701. The end of the conduit 701 away from the reflux cylinder 7 is provided with a temporary storage tank 12 that communicates with the reflux port at the top of the extractive distillation column 1. The output end of the discharge cylinder 8 is provided with a discharge pipe 801. A one-way valve is connected in series on the reflux main pipe 13, the conduit 701, and the discharge pipe 801.

[0042] When the second piston 9 slides to the outside of the cylinder, the internal chamber volume of the reflux cylinder 7 and the discharge cylinder 8 increases, creating a negative pressure. The condensed liquid in the reflux tank 102 is drawn into the two cylinders through the reflux main pipe 13 and the corresponding one-way valve. When the second piston 9 slides to the inside of the cylinder, the internal chamber volume decreases and the pressure increases. The liquid in the reflux cylinder 7 is pressurized to the temporary storage tank 12 through the conduit 701 and the corresponding one-way valve, and finally sent to the top reflux port of the extractive distillation column 1 as reflux liquid. The liquid in the discharge cylinder 8 is discharged outward through the discharge pipe 801 and the corresponding one-way valve. The one-way valves on each pipeline strictly control the unidirectional flow of liquid to avoid backflow of liquid during piston reversal and ensure that the ratio of reflux flow to discharge flow is accurate and constant.

[0043] In this embodiment, a solvent inlet pipe 201 is connected between the input ends of the two sets of solvent cylinders 2, and a solvent outlet pipe 202 is provided between the output ends of the two sets of solvent cylinders 2, which is connected to the solvent port at the top of the extraction distillation column 1. Both the solvent inlet pipe 201 and the solvent outlet pipe 202 are equipped with one-way valves.

[0044] When the first piston 4 slides to the outside of the solvent cylinder 2, the internal chamber volume of the solvent cylinder 2 increases, creating a negative pressure. The extraction solvent is drawn into the solvent cylinder 2 through the solvent inlet pipe 201 and the corresponding one-way valve. When the first piston 4 slides to the inside of the solvent cylinder 2, the solvent inside the cylinder is pressurized and is pumped to the top solvent port of the extraction distillation column 1 through the solvent outlet pipe 202 and the corresponding one-way valve. The two sets of solvent cylinders 2 are symmetrically arranged and operate synchronously, which can ensure the continuity and stability of solvent delivery. The delivery volume is precisely controlled by the stroke of the first piston 4, effectively improving the metering accuracy of solvent feeding.

[0045] In this embodiment, a raw material inlet pipe 301 is connected between the input ends of the two sets of raw material cylinders 3, and a raw material outlet pipe 302 is provided between the output ends of the two sets of raw material cylinders 3, which is connected to the raw material inlet on the side of the extraction distillation column 1. Both the raw material inlet pipe 301 and the raw material outlet pipe 302 are equipped with one-way valves.

[0046] When the first piston 4 slides to the outside of the raw material cylinder 3, the internal chamber volume of the raw material cylinder 3 increases, creating a negative pressure. The raw material to be processed is drawn into the raw material cylinder 3 through the raw material inlet pipe 301 and the corresponding one-way valve. When the first piston 4 slides to the inside of the raw material cylinder 3, the raw material in the cylinder is pressurized and is pushed to the side raw material inlet of the extractive distillation column 1 through the raw material outlet pipe 302 and the corresponding one-way valve. The raw material cylinder 3 and the solvent cylinder 2 are synchronously driven by the same reciprocating mechanism 6, and their piston strokes are completely consistent. The conveying volume ratio of a single cycle is fixed, which eliminates the error superposition problem caused by the independent detection of the dual flow meters from the mechanical structure, ensuring the long-term stability of the solvent ratio.

[0047] In this embodiment, the inner diameters of the reflux cylinder 7 and the discharge cylinder 8, and the reciprocating stroke of the second piston 9 are matched so that the ratio of their effective working volumes is equal to a preset reflux ratio.

[0048] The second piston 9 in the reflux cylinder 7 and the discharge cylinder 8 are driven by the same telescopic mechanism 11, and their reciprocating strokes are exactly the same. By setting different inner diameters of the cylinders, the ratio of their effective working volumes is equal to the preset reflux ratio. During the operation of the equipment, the amount of reflux liquid delivered and the amount of produced liquid delivered in a single cycle always maintain a fixed ratio, without the need for flow sensor detection and closed-loop regulation by the regulating valve, thus ensuring the stability of the purity of the product at the top of the tower.

[0049] In this embodiment, the outer diameter of the lever 606 is adapted to the inner side of the rectangular frame plate 607, and both the outer wall of the lever 606 and the inner side of the rectangular frame plate 607 are coated with a wear-resistant coating.

[0050] The wear-resistant coating applied to the outer wall of the lever 606 and the inner side of the rectangular frame plate 607 can significantly reduce the wear rate of the mating surfaces, reduce the expansion of the mating clearance after long-term operation, ensure the positional accuracy of the reciprocating transmission, extend the service life of the mechanism, and reduce the maintenance frequency and operating costs of the equipment.

[0051] The solutions in Embodiment 1 and Embodiment 2 will be further described below with reference to their specific working methods. After the equipment is started, the drive motor 601 starts to run, and the output rotational power is divided into two transmission paths through the active bevel gear 602: one path drives the two sets of first shafts 604 to rotate synchronously in opposite directions through the upper and lower symmetrical driven bevel gears 603, and the other path drives the arm 1104 to rotate synchronously through the second shaft 1103.

[0052] When the first shaft 604 rotates, the crank-slider mechanism composed of the crossbar 605, the lever 606, and the rectangular frame plate 607 converts the rotational motion into the horizontal reciprocating linear motion of the first piston rod 5, driving the first piston 4 to slide back and forth in the solvent cylinder 2 and the raw material cylinder 3. With the cooperation of the one-way valves on each pipeline, the solvent cylinder 2 continuously and quantitatively feeds the extractant into the top of the extractive distillation column 1, and the raw material cylinder 3 simultaneously and quantitatively feeds the raw material into the side of the extractive distillation column 1. The ratio of the two feeds is determined by the piston stroke. Rotating the screw 610 can adjust the rotation radius of the lever 606, change the piston stroke, and realize stepless adjustment of the solvent ratio.

[0053] Meanwhile, the second shaft 1103 drives the arm 1104 to rotate. Through the crank-connecting rod mechanism composed of the connecting rod 1102 and the fixed plate 1101, the rotational motion is converted into the horizontal reciprocating linear motion of the second piston rod 10, which drives the second piston 9 to slide back and forth in the reflux cylinder 7 and the discharge cylinder 8. With the cooperation of the one-way valves on each pipeline, the reflux cylinder 7 and the discharge cylinder 8 synchronously draw in condensate from the reflux tank 102, and then send the reflux liquid back to the top of the extractive distillation column 1 and discharge the produced liquid outward, respectively. The effective volume of the reflux cylinder 7 and the discharge cylinder 8 is configured according to the preset reflux ratio, so the reflux flow rate and the produced flow rate always maintain a fixed ratio.

[0054] The raw material and extractant undergo thorough contact and mass transfer within the extractive distillation column 1, achieving the separation of aromatics and non-aromatics. The vapor phase at the top of the column is condensed by condenser 101 and flows into reflux tank 102, while the material at the bottom of the column is heated and circulated by reboiler 103. The entire system operates through a single mechanical drive source, simultaneously achieving precise and constant control of the solvent ratio and reflux ratio. It eliminates the need for complex electronic control systems, ensuring stable and reliable operation and effectively improving the purification efficiency and product quality stability of high-boiling-point aromatic solvents.

[0055] 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. A solvent extraction and distillation coupled purification apparatus for high-boiling-point aromatic hydrocarbons, comprising an extractive distillation column (1), wherein a condenser (101) and a reflux tank (102) are provided at the top of the extractive distillation column (1), and a reboiler (103) is provided at the bottom of the column, characterized in that, Also includes: Solvent cylinder (2) and raw material cylinder (3). There are two solvent cylinders (2) and they are symmetrically arranged on both sides of the top of the extractive distillation column (1). There are two raw material cylinders (3) and they are symmetrically arranged on both sides of the extractive distillation column (1) and located below the solvent cylinders (2). The raw material cylinders (3) and the solvent cylinders (2) are vertically opposite each other. The first piston (4) is slidably disposed inside the solvent cylinder (2) and the raw material cylinder (3); The first piston rod (5) is fixedly connected to the outer end of the first piston (4) and extends out of the solvent cylinder (2) and the raw material cylinder (3); A reciprocating mechanism (6) is located on the side of the extractive distillation column (1) and is used to drive the first piston rod (5) to reciprocate. The reflux cylinder (7) and the discharge cylinder (8) are located on the side of the extractive distillation column (1) and are connected to the liquid outlet of the reflux tank (102). The internal volume of the reflux cylinder (7) and the discharge cylinder (8) is set according to the reflux ratio. The second piston (9) is slidably disposed inside the reflux cylinder (7) and the discharge cylinder (8); The second piston rod (10) is fixedly connected to the outer end of the second piston (9) and extends out of the outside of the return liquid cylinder (7) and the discharge cylinder (8); The telescopic mechanism (11) is connected between the second piston rods (10) and is used to synchronously drive the second piston (9) in the return liquid cylinder (7) and the discharge cylinder (8) to slide. The telescopic mechanism (11) and the reciprocating mechanism (6) are mechanically linked and powered by the reciprocating mechanism (6) to operate synchronously.

2. The high-boiling-point aromatic hydrocarbon solvent extraction and distillation coupled refining equipment according to claim 1, characterized in that: The reciprocating mechanism (6) includes a drive motor (601), a driving bevel gear (602), a driven bevel gear (603), a first shaft (604), a crossbar (605), a lever (606), a rectangular frame plate (607), and a translation assembly; The drive motor (601) is fixedly installed on the outer wall of the extraction distillation column (1). The driving bevel gear (602) is installed at the output end of the drive motor (601). The driven bevel gear (603) is symmetrically meshed on the upper and lower sides of the driving bevel gear (602). The first shaft (604) is coaxially fixed on the side of the driven bevel gear (603) away from the driving bevel gear (602). The crossbar (605) is fixedly installed on the first shaft (604). A lever (606) is vertically installed on the outside of the crossbar (605). The rectangular frame plate (607) is fixedly installed between the two sets of first piston rods (5) on the same plane. The lever (606) passes through the rectangular frame plate (607) and is slidably connected to it. The crossbar (605) is provided with a translation component for fine-tuning the position of the lever (606) to control the sliding amplitude of the first piston (4).

3. The high-boiling-point aromatic hydrocarbon solvent extraction and distillation coupled refining equipment according to claim 2, characterized in that: The translation component includes a slot (608), a slider (609), and a screw (610); A strip groove (608) is formed on a crossbar (605), a slider (609) is slidably disposed in the strip groove (608), one end of a lever (606) is rotatably connected to the slider (609), and a screw (610) is rotatably installed in the strip groove (608) and threadedly connected to the slider (609).

4. The high-boiling-point aromatic hydrocarbon solvent extraction and distillation coupled refining equipment according to claim 3, characterized in that: One end of the screw (610) extends to the outside of the crossbar (605), and an adjustment groove is provided at the end of the screw (610).

5. The high-boiling-point aromatic hydrocarbon solvent extraction and distillation coupled refining equipment according to claim 2, characterized in that: The telescopic mechanism (11) includes a fixed plate (1101), a connecting rod (1102), a second shaft (1103), and an arm (1104). The fixing plate (1101) is fixedly installed at the ends of the two sets of second piston rods (10). The second shaft (1103) is coaxially fixed on the side of the active bevel gear (602). An arm (1104) is fixedly installed at the end of the second shaft (1103) away from the active bevel gear (602). A connecting rod (1102) is hinged between the end of the arm (1104) and the fixing plate (1101).

6. The high-boiling-point aromatic hydrocarbon solvent extraction and distillation coupled refining equipment according to claim 1, characterized in that: The input end of the reflux cylinder (7) and the discharge cylinder (8) are connected to the liquid outlet end of the reflux tank (102) via a reflux main pipe (13). The output end of the reflux cylinder (7) is connected to a conduit (701). The end of the conduit (701) away from the reflux cylinder (7) is provided with a temporary storage tank (12) that is connected to the reflux port at the top of the extractive distillation column (1). The output end of the discharge cylinder (8) is provided with a discharge pipe (801). A one-way valve is connected in series on the reflux main pipe (13), the conduit (701) and the discharge pipe (801).

7. The high-boiling-point aromatic hydrocarbon solvent extraction and distillation coupled refining equipment according to claim 1, characterized in that: A solvent inlet pipe (201) is connected between the input ends of the two sets of solvent cylinders (2), and a solvent outlet pipe (202) is provided between the output ends of the two sets of solvent cylinders (2) to communicate with the solvent port at the top of the extraction distillation column (1). Both the solvent inlet pipe (201) and the solvent outlet pipe (202) are equipped with one-way valves.

8. The high-boiling-point aromatic hydrocarbon solvent extraction and distillation coupled refining equipment according to claim 1, characterized in that: A raw material inlet pipe (301) is connected between the input ends of the two sets of raw material cylinders (3), and a raw material outlet pipe (302) is provided between the output ends of the two sets of raw material cylinders (3) to communicate with the raw material inlet on the side of the extraction distillation column (1). Both the raw material inlet pipe (301) and the raw material outlet pipe (302) are equipped with one-way valves.

9. The high-boiling-point aromatic hydrocarbon solvent extraction and distillation coupled refining equipment according to claim 1, characterized in that: The inner diameter of the reflux cylinder (7) and the discharge cylinder (8) and the reciprocating stroke of the second piston (9) are matched so that the ratio of their effective working volumes is equal to the preset reflux ratio.

10. The high-boiling-point aromatic hydrocarbon solvent extraction and distillation coupled refining equipment according to claim 2, characterized in that: The outer diameter of the lever (606) is adapted to the inner side of the rectangular frame plate (607), and both the outer wall of the lever (606) and the inner side of the rectangular frame plate (607) are coated with a wear-resistant coating.

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