A multi-stage treatment device and method for plant extraction and processing wastewater.

Abstract

This invention discloses a multi-stage treatment device and method for plant extraction and processing wastewater, relating to the field of organic wastewater treatment technology. The multi-stage treatment device includes a treatment tower body, within which multiple sets of tray assemblies are arranged axially at equal intervals. Each tray assembly, from top to bottom, includes a first guide shroud, an isolation sleeve, and a second guide shroud arranged coaxially. The first guide shroud has a bowl-shaped structure, with an upper tray component coaxially arranged on its inner side. Through the complementary nesting of the bowl-shaped structure of the first guide shroud and the inverted bowl-shaped structure of the second guide shroud, reverse flow of the gas and liquid phases is achieved, improving the heat exchange effect in this process. A physical isolation barrier is formed through the upper and lower separation rings, forcibly guiding the high-viscosity wastewater to flow directionally along the guide shroud wall, completely blocking impurities such as sugars and colloids from entering the upper and lower pores, solving the problem of pore blockage in traditional treatment tower trays, and extending the continuous operation cycle of the equipment.

Description

Technical Field

[0001] This invention relates to the field of organic wastewater treatment technology, specifically to a multi-stage treatment device and method for plant extraction and processing wastewater. Background Technology

[0002] During the process of extracting target products from plant raw materials through crushing, soaking, extraction, and refining, a large amount of waste liquid containing natural organic pollutants is generated. The composition of this type of waste liquid is complex and fluctuates significantly, covering plant-derived substances such as cellulose, hemicellulose, sugars, and proteins, as well as organic solvents such as alcohols. It is a typical high-concentration and difficult-to-treat organic waste liquid. With the development of the plant extraction industry, its water consumption is increasing, and water pollution problems are becoming more and more prominent. If the wastewater is not treated, it not only becomes a wasteful resource that can no longer be used, but also, if discharged directly without treatment, it will inevitably seriously pollute natural water bodies, making the limited available water resources even more scarce. Furthermore, if the organic alcohol solvents and sugars in the plant extraction and processing waste liquid are not treated, they will not only harm the surrounding environment, but also lead to a large loss of resources.

[0003] Due to differences in production processes and finished products, the quality of wastewater exhibits strong fluctuations. Its high viscosity and tendency to scale pose serious challenges to traditional treatment equipment: the pores of the trays in conventional treatment towers are easily blocked by sugars and colloids, resulting in obstructed steam channels and reduced separation efficiency; the fixed tray structure cannot respond to pressure fluctuations, and insufficient operational flexibility can lead to flooding or leakage accidents. Furthermore, the low gas-liquid contact efficiency limits the utilization of thermal energy, resulting in high steam energy consumption. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a multi-stage treatment device and method for plant extraction and processing wastewater, solving the problems raised in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a multi-stage treatment device for plant extraction and processing wastewater, comprising a pretreatment mechanism, a treatment tower, and a membrane filtration mechanism. Multiple sets of tray assemblies are equidistantly arranged along the axial direction within the treatment tower. Each tray assembly includes, from top to bottom, a first guide shroud, an isolation sleeve, and a second guide shroud arranged coaxially. The first guide shroud has a bowl-shaped structure, with an upper tray component coaxially arranged on its inner side. The upper tray component includes upper vent holes formed on the surface of the first guide shroud and an upper separation ring fixed to the inner side of the first guide shroud. The upper separation ring extends and covers the upper vent holes to guide the liquid phase away from the upper vent holes. The second guide shroud... The structure is an inverted bowl shape, with a lower tower plate component coaxially arranged on the outer side. The lower tower plate component includes a lower gas hole opened on the surface of the second guide shroud and a lower separation ring fixed to the outside of the second guide shroud. The lower separation ring extends and covers the lower gas hole to guide the liquid phase away from the lower gas hole. A drain trough is provided at the edge of the second guide shroud, and a flow guide plate is installed on both sides of the drain trough. A conical balance plate is installed between the first and second guide shrouds of adjacent tower plate components. The conical balance plate separates the gap between the two flow guide plates into a gas port and a water port. The conical balance plate can slide along the axial direction of the treatment tower body driven by the rising gas pressure and gravity in the treatment tower body to dynamically adjust the flow cross section of the water port.

[0006] Furthermore, the isolation sleeve has an hourglass-shaped structure, which is filled with heat-insulating cotton, and the surface of the isolation sleeve is provided with a vibrating sheet. The vibrating sheet vibrates under the impact of the rising airflow to disturb the steam flow field.

[0007] Furthermore, the upper tower plate component also includes an upper flow baffle ring installed on the upper end of the inner ring of the upper separation ring, and an upper water distribution net is installed between the upper flow baffle ring and the first flow guide shroud; the lower tower plate component also includes a lower flow baffle ring installed on the outer ring of the lower separation ring, and a lower water distribution net is installed between the lower flow baffle ring and the second flow guide shroud.

[0008] Furthermore, the first flow guide shroud has a flow port at its bottom, and the processing tower body has a bushing. The bushing is fixedly connected to the second flow guide shroud, and the gap between the bushing and the flow port forms a downward liquid phase channel.

[0009] Furthermore, a rotating shaft is rotatably installed inside the bushing, and a fan blade is fixed at the lower end of the rotating shaft; a reboiler is provided at the lower end of the outer side of the processing tower body, and a steam output pipe is installed at the output end of the reboiler. The outlet of the steam output pipe is arranged tangentially along the processing tower body to drive the fan blade to rotate.

[0010] Furthermore, a diverter is installed inside the processing tower near the upper end. The diverter is fixedly connected to the upper end of the rotating shaft, and both ends of the diverter are conical structures with radial flow channels on their surfaces.

[0011] Furthermore, the conical balance disc is made of high-temperature resistant lightweight plastic material, and a groove is provided in the middle of the conical balance disc. A limiting guide rail is provided on the outside of the bushing that is slidably connected to the groove. When the conical balance disc slides to the lowest end of the limiting guide rail, the minimum distance between the conical balance disc and the lower first guide shroud is 0.5cm.

[0012] Furthermore, it also includes: a baffle plate, fixed inside the upper part of the processing tower; and a condenser, located outside the processing tower, wherein the condenser is used to condense the gas escaping from the processing tower, and its refrigerant is the pretreated plant extract processing waste liquid stock solution, and its refrigerant output end extends to the upper part of the processing tower.

[0013] Furthermore, a raw liquid feed pipe is installed near the upper end of the processing tower body, and a tower bottom discharge pipe is provided at the lower end of the processing tower body. An overflow pipe is also installed on the processing tower body, and the overflow pipe is located between the steam output pipe and the tower bottom discharge pipe.

[0014] This invention also provides a multi-stage treatment method for plant extraction and processing wastewater, using the multi-stage treatment device for plant extraction and processing wastewater provided in this embodiment, including the following steps:

[0015] S1. Pretreatment: The plant extract processing waste liquid is treated by sedimentation, filtration, and pH adjustment to 4.5-5.5 to obtain the original plant extract processing waste liquid;

[0016] S2. Multi-stage treatment: The raw liquid of plant extraction and processing waste liquid is treated at least twice by a multi-stage treatment device to obtain alcohol solvent and de-alcoholized liquid.

[0017] S3. Membrane filtration: The alcohol-dehydrogenated liquid at 80-85℃ is directly filtered through a ceramic microfiltration membrane, and then treated with a ceramic spiral wound nanofiltration membrane to separate low-sugar, low-salt permeate and a sugar-salt mixture.

[0018] S4. Energy Recovery: Low-sugar, low-salt permeate is placed in an IC anaerobic reactor to produce biogas, which is then burned to provide auxiliary heat energy for the reboiler.

[0019] The present invention has the following beneficial effects:

[0020] (1) The multi-stage treatment device for plant extraction and processing waste liquid achieves reverse flow of gas and liquid phases by complementing and nesting the bowl-shaped structure of the first guide hood and the inverted bowl-shaped structure of the second guide hood, thereby improving the heat exchange effect in this process. Through the upper separation ring and the lower separation ring, a physical isolation barrier is formed, which forces the high viscosity waste liquid to flow in a directional manner along the guide hood wall, completely blocking the intrusion of impurities such as sugar and colloid into the upper and lower pores, solving the problem of pore blockage in the traditional treatment tower trays, and extending the continuous operation cycle of the equipment.

[0021] (2) The multi-stage treatment device for plant extraction and processing waste liquid drives the balance plate to slide along the axis through the opposite force of air pressure and gravity, so that the water inlet automatically moves upward to expand the flow cross section under high pressure conditions, effectively suppressing the risk of flooding, and automatically sinks to shrink the water inlet under low pressure conditions, maintaining the stability of the fractionation pressure difference in the tower. The adaptive mechanism greatly improves the operational flexibility and overcomes the problem of separation efficiency reduction caused by air pressure fluctuations in traditional fixed tower plates.

[0022] (3) The multi-stage treatment device for plant extraction and processing waste liquid reduces axial heat loss by using the insulation cotton inside the isolation sleeve to maintain the temperature gradient inside the treatment tower. It utilizes the high-frequency micro-amplitude vibration generated by the vibration of the vibrating sheet on the surface of the isolation sleeve under the excitation of the rising airflow to continuously disturb the vapor boundary layer and break the gas-liquid mass transfer resistance. The hourglass structure of the isolation sleeve, together with the first and second guide hoods, forms a reverse nested structure, which can extend the gas-liquid phase passage path in the gas-liquid phase flow, realize continuous heat exchange, and significantly improve the thermal energy utilization rate.

[0023] (4) The multi-stage treatment method for plant extraction and processing waste liquid uses pre-treated waste liquid as a condenser refrigerant to recover the waste heat of the top steam of the tower. After preheating, it is returned to the tower through a secondary feed pipe, reducing the dependence on external refrigerant. The high-temperature direct membrane filtration of the dehydrogenated liquid uses waste heat to reduce the viscosity of the sugar solution and delay membrane fouling. The biogas produced by IC anaerobic production provides auxiliary heat energy for the reboiler, forming an internal circulation chain of waste liquid treatment - energy recovery - system energy supply, which greatly reduces the overall energy consumption.

[0024] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0025] Figure 1 Structural diagram of a multi-stage treatment device for wastewater from plant extraction and processing;

[0026] Figure 2 Internal structure diagram of a multi-stage treatment device for wastewater from plant extraction and processing;

[0027] Figure 3 Multi-stage treatment device for plant extraction and processing wastewater Figure 2 The main view;

[0028] Figure 4 A schematic diagram of the tray assembly in a multi-stage treatment device for plant extraction and processing wastewater;

[0029] Figure 5 Multi-stage treatment device for plant extraction and processing wastewater Figure 4 Another perspective view;

[0030] Figure 6 A schematic diagram of the installation structure of the conical balance disc in a multi-stage treatment device for plant extraction and processing waste liquid;

[0031] Figure 7 Multi-stage treatment device for plant extraction and processing wastewater Figure 6 The main view;

[0032] Figure 8 Multi-stage treatment device for plant extraction and processing wastewater Figure 7 Enlarged view of point A in the middle;

[0033] Figure 9 A diagram showing the positional relationship between the first and second guide hoods in a multi-stage treatment device for plant extraction and processing wastewater;

[0034] Figure 10 Multi-stage treatment device for plant extraction and processing wastewater Figure 9 Another perspective view;

[0035] Figure 11 A diagram showing the distribution of pores in the upper and lower layers of a multi-stage treatment device for plant extraction and processing wastewater.

[0036] Figure 12 A schematic diagram of the baffle plate structure in a multi-stage treatment device for plant extraction and processing wastewater;

[0037] Figure 13 A schematic diagram of a multi-stage treatment method for wastewater from plant extraction and processing.

[0038] In the diagram, 1. Processing tower body; 2. Base; 3. Tower reboiler outlet pipe; 4. Overflow pipe; 5. Tower reboiler outlet pipe; 6. Reboiler; 7. Steam outlet pipe; 8. Raw liquid feed pipe; 9. Condenser; 10. Condenser inlet; 11. Condenser outlet; 12. Tower top gas outlet pipe; 13. Product outlet pipe; 14. Secondary feed pipe; 15. Baffle plate; 16. Isolation sleeve; 17. First flow guide shroud; 18. Second flow guide shroud; 19. Flow divider; 20. Fan blade; 21. Rotating shaft; 22. Flow channel; 23. 24. Drainage trough; 25. Vibrating plate; 26. Conical balance plate; 27. Gas inlet; 28. Water inlet; 29. ​​Bushing; 30. Limiting guide rail; 31. Slide groove; 32. Lower tray components; 3201. Lower separation ring; 3202. Lower vent; 3203. Lower baffle ring; 3204. Lower water distribution network; 33. Upper tray components; 3301. Upper separation ring; 3302. Upper vent; 3303. Upper baffle ring; 3304. Upper water distribution network; 34. Flow port. Detailed Implementation

[0039] 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.

[0040] In the description of this invention, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inner", "around", etc., which indicate orientation or positional relationship, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this invention.

[0041] The following is based on Figure 1 - Figure 13 This invention describes a multi-stage treatment device and method for plant extraction and processing wastewater provided in embodiments of the present invention.

[0042] Please see Figure 1 - Figure 12 The present invention provides a technical solution: a multi-stage treatment device for plant extraction and processing waste liquid, including a pretreatment mechanism, a treatment tower 1 and a membrane filtration mechanism. Multiple sets of tower plate assemblies are arranged at equal intervals along the axial direction in the treatment tower 1. There are at least three sets of tower plate assemblies. Each set of tower plate assemblies includes, from top to bottom, a first guide shroud 17, an isolation sleeve 16 and a second guide shroud 18 arranged coaxially.

[0043] The first guide shroud 17 provided in this embodiment has a bowl-shaped structure, with its edge fixed inside the processing tower body 1. At least three sets of upper tower plate components 33 are coaxially provided on its inner side. The maximum outer diameter of each set of upper tower plate components 33 changes stepwise along the inner diameter of the first guide shroud 17. The upper tower plate component 33 provided in this embodiment includes upper air holes 3302 opened on the surface of the first guide shroud 17 and upper separation rings 3301 fixed on the inner side of the first guide shroud 17. The upper air holes 3302 are evenly arranged around the circumference of the first guide shroud 17. The upper separation rings 3301 extend and cover the upper air holes 3302 to guide the liquid phase away from the upper air holes 3302, so that the upper liquid phase does not pass through the upper air holes 3302 when it flows downward, thereby reducing the ventilation pressure of the upper air holes 3302, effectively preventing the upper air holes 3302 from being blocked, and extending the service life of the upper air holes 3302.

[0044] The second guide shroud 18 provided in this embodiment has an inverted bowl-shaped structure, with its edge fixed inside the processing tower body 1. A lower tower plate component 32 is coaxially arranged on its outer side. It should be noted that the number of lower tower plate components 32 is less than the number of upper tower plate components 33, and there are at least two sets. This ensures that the air pressure in the lower layer of the tower plate assembly is greater than that in the upper layer during the ventilation process, which is beneficial for the stepwise change of air pressure and thus prevents turbulent upward steam rise. The lower tower plate component 32 provided in this embodiment includes components formed on the surface of the second guide shroud 18. The lower vent 3202 and the lower separation ring 3201 fixed to the outside of the second guide shroud 18 are provided. The lower vent 3202 is evenly arranged around the second guide shroud 18. The lower separation ring 3201 extends and covers the lower vent 3202 to guide the liquid phase away from the lower vent 3202, so that the upper liquid phase does not pass through the lower vent 3202 when it flows downward, thereby reducing the ventilation pressure of the lower vent 3202, effectively preventing the lower vent 3202 from being blocked, and extending the service life of the lower vent 3202.

[0045] To further achieve adaptive adjustment of the internal gas pressure of the treatment tower 1, the second guide shroud 18 provided in this solution is provided with a drain trough 24 at its edge. Both sides of the drain trough 24 are equipped with guide plates 23. Preferably, the guide plates 23 are provided with guide grooves to ensure that the liquid phase can slide down the inner wall of the treatment tower 1 along the guide plates 23. A conical balance plate 26 is installed between the first guide shroud 17 and the second guide shroud 18 of two adjacent tower plate assemblies. The conical balance plate 26 divides the gap between the two guide plates 23 into a gas inlet 27 and a water inlet 28. It should be noted that the guide plates 23 are long enough to meet the ventilation requirements of the gas inlet 27. Since the upper liquid phase and the lower gas phase meet at the water inlet 28, the flow pressure at the water inlet 28 increases. When the weight of the conical balance plate 26 is less than the rising gas pressure it experiences, the conical balance plate 26 can move upwards along the axial direction of the treatment tower 1, allowing the water inlet 28 to flow upwards. The increased flow cross-section of nozzle 28 reduces the flow pressure at the inlet 28. When the weight of the conical balance plate 26 exceeds the upward air pressure, the internal air pressure of the treatment tower 1 is low. Driven by gravity, the conical balance plate 26 moves downward along the axial direction of the treatment tower 1, thereby reducing the flow cross-section of nozzle 28. This allows steam to accumulate in the lower layer of the tower plate assembly, ensuring stable internal air pressure and improving treatment efficiency. Preferably, both the first guide shroud 17 and the second guide shroud 18 are made of metals with good thermal conductivity and corrosion resistance, such as copper or aluminum alloy. Due to the opposite flow direction of the gas and liquid phases, continuous heat exchange occurs between the first guide shroud 17 and the second guide shroud 18, thereby improving thermal efficiency. The structural characteristics of the first guide shroud 17 and the second guide shroud 18 form complementary channels, guiding the gas and liquid to flow in opposite directions through geometric configuration, enhancing interphase contact efficiency.

[0046] like Figure 6 and Figure 7As shown, in order to achieve a stepwise change in the internal thermal efficiency of the treatment tower 1, the isolation sleeve 16 provided in this embodiment has an hourglass-shaped structure, which is filled with thermal insulation cotton. The surface of the isolation sleeve 16 is provided with a vibrating sheet 25. The vibrating sheet 25 vibrates under the impact of the rising airflow to disturb the steam flow field and improve the gas-liquid phase contact effect. The thermal insulation cotton can not only achieve thermal insulation in the vertical direction of the treatment tower 1 to build a pressure gradient, suppress steam turbulence, and improve separation stability, but also reduce the noise generated by the vibrating sheet 25 and the airflow vibration. In addition, the hourglass-shaped isolation sleeve 16 can extend the gas-liquid phase travel path and compress the passage space of the gas and liquid phases, thereby improving the gas-liquid contact effect and ensuring the heat transfer effect.

[0047] like Figure 7 - Figure 11 As shown, to further improve the heat transfer effect between the gas and liquid phases, the upper tower plate 33 provided in this embodiment also includes an upper baffle ring 3303 installed on the upper end of the inner ring of the upper separation ring 3301. An upper water distribution net 3304 is installed between the upper baffle ring 3303 and the first guide shroud 17. The upper baffle ring 3303 causes the liquid phase to accumulate on the surface of the upper separation ring 3301, and allows the liquid to be evenly distributed along the upper water distribution net 3304, thus achieving a good heat transfer effect between the gas and liquid phases. To further improve heat transfer efficiency, the lower tower plate 32 also includes a lower baffle ring 3203 installed on the outer ring of the lower separation ring 3201. A lower water distribution net 3204 is installed between the lower baffle ring 3203 and the second guide shroud 18. The lower baffle ring 3203 allows the liquid phase to accumulate on the surface of the lower separation ring 3201 and allows the liquid to be evenly distributed along the lower water distribution net 3204, achieving effective contact between the gas phase and the liquid phase and further improving the heat transfer efficiency.

[0048] like Figure 9 As shown, in order to facilitate the outflow of the liquid phase inside the first guide shroud 17, a flow port 34 is provided at the bottom of the first guide shroud 17. A bushing 29 is provided inside the treatment tower body 1. The bushing 29 is fixedly connected to the second guide shroud 18, and the gap between the bushing 29 and the flow port 34 forms a downward channel for the liquid phase, so that the upper liquid phase flows into the middle of the lower second guide shroud 18, thereby achieving a uniform arrangement of the liquid phase.

[0049] like Figure 3 and Figure 5 As shown, to avoid uneven upward movement of the gas phase inside the treatment tower 1, a rotating shaft 21 is rotatably installed inside the bushing 29. A fan blade 20 is fixed at the lower end of the rotating shaft 21. A reboiler 6 is provided at the lower outer side of the treatment tower 1. The reboiler 6 is connected to the bottom of the treatment tower 1 through the tower bottom output pipe 5. A steam output pipe 7 is installed at the output end of the reboiler 6. The outlet of the steam output pipe 7 is tangentially arranged along the treatment tower 1 to drive the fan blade 20 to rotate, thereby making the gas phase uniformly input into the tower plate assembly.

[0050] like Figure 3 , Figure 4 and Figure 7 As shown, in order to achieve uniformity during liquid phase input, a distributor 19 is installed inside the treatment tower 1 near the upper end. The distributor 19 is fixedly connected to the upper end of the rotating shaft 21, and both ends of the distributor 19 are conical structures with radial flow channels 22 on their surfaces. The rotation of the rotating shaft 21 causes the distributor 19 to rotate, thereby causing the liquid phase flowing through the distributor 19 to diffuse towards the inner wall of the treatment tower 1, improving the uniformity of liquid phase input. In addition, the flow channels 22 can improve the gas-liquid contact effect and further ensure the gas-liquid heat transfer effect.

[0051] like Figure 6 - Figure 8 As shown, in order to enable the conical balance disk 26 to slide inside the processing tower body 1, the conical balance disk 26 provided in this embodiment is made of high temperature resistant lightweight plastic material, and the conical balance disk 26 is provided with a sliding groove 31 in the middle, and the bushing 29 is provided with a limiting guide rail 30 that is slidably connected to the sliding groove 31 on the outside. When the conical balance disk 26 slides to the lowest end of the limiting guide rail 30, the minimum distance between the conical balance disk 26 and the lower first flow guide shroud 17 is 0.5cm to ensure the minimum downward flow of the upper liquid phase.

[0052] like Figure 1 - Figure 3 As shown, the multi-stage treatment device for plant extraction and processing waste liquid provided in this embodiment also includes a base 2 fixed at the bottom of the treatment tower 1, a baffle 15 at the upper inside of the treatment tower 1, and a condenser 9 located on the outside of the treatment tower 1. The condenser 9 is used to condense the gas that flows out of the treatment tower 1. Its refrigerant is the pretreated plant extraction and processing waste liquid stock solution, and its refrigerant output end extends to the upper inside of the treatment tower 1.

[0053] It should be noted that a tower top outlet pipe 12 connected to the heat medium input end of the condenser 9 is installed at the top of the treatment tower 1. The pretreated plant extract processing waste liquid is input at the condenser pipe inlet 10. After exchanging heat with the plant extract processing waste liquid, the outgoing gas condenses to form a product liquid. The product liquid can flow into the next stage treatment tower 1 through the product output pipe 13 to achieve multi-stage treatment and improve product purity. After exchanging heat with the outgoing gas, the plant extract processing waste liquid flows into the secondary feed pipe 14 inside the treatment tower 1 through the condenser pipe outlet 11, thereby reducing heat loss.

[0054] like Figure 1 - Figure 3 As shown, a raw liquid feed pipe 8 is installed near the upper end of the processing tower body 1, and a tower bottom discharge pipe 3 is provided at the lower end of the processing tower body 1. An overflow pipe 4 is also installed on the processing tower body 1, and the overflow pipe 4 is located between the steam output pipe 7 and the tower bottom discharge pipe 3.

[0055] During use (operation), the pretreated plant extract processing waste liquid is fed into the bottom of the treatment tower 1 through the raw liquid feed pipe 8. The raw liquid is then fed into the reboiler 6 through the tower bottom output pipe 5, which generates steam, which is then fed into the treatment tower 1 through the steam output pipe 7. The steam drives the fan blades 20 to rotate, so that the gas phase is evenly fed into the tower plate assembly. As the gas pressure at the bottom of the treatment tower 1 increases, the steam rises and further enters the tower plate assembly.

[0056] In this process, the first cup-shaped flow guide shroud 17 serves as the upper carrier, and the second cup-shaped flow guide shroud 18 serves as the lower carrier, enabling continuous heat exchange between the gas and liquid phases, thereby improving thermal efficiency. The structural characteristics of the first flow guide shroud 17 and the second flow guide shroud 18 form complementary channels, and the geometric configuration guides the gas and liquid to flow in opposite directions, enhancing the interphase contact efficiency. The upper separation ring 3301, upper pores 3302, lower separation ring 3201, and lower pores 3202 physically isolate the liquid and gas phases, preventing substances such as sugars and colloids from clogging the upward steam channel from the source.

[0057] When gas and liquid pass between two adjacent tray assemblies, if the weight of the conical balance plate 26 is less than the rising gas pressure it experiences, the conical balance plate 26 can move upward along the axial direction of the treatment tower 1, increasing the flow cross-section of the nozzle 28 and thus reducing the flow pressure at the nozzle 28. When the weight of the conical balance plate 26 is greater than the rising gas pressure it experiences, the internal gas pressure of the treatment tower 1 is lower. Driven by gravity, the conical balance plate 26 moves downward along the axial direction of the treatment tower 1, thereby reducing the flow cross-section of the nozzle 28. This allows steam to accumulate in the lower layer of the tray assembly, ensuring stable internal gas pressure and improving the treatment effect.

[0058] As the steam rises, it eventually enters the condenser 9 through the top outlet pipe 12. At this time, the pretreated plant extract processing waste liquid is introduced into the condenser pipe inlet 10. After exchanging heat with the plant extract processing waste liquid, the outgoing gas condenses to form the product liquid. The product liquid can flow into the next stage processing tower 1 through the product outlet pipe 13 to achieve multi-stage processing and improve product purity. After exchanging heat with the outgoing gas, the plant extract processing waste liquid flows into the secondary feed pipe 14 inside the processing tower 1 through the condenser pipe outlet 11, thereby reducing heat loss. At the same time, the flow rate of the raw liquid feed pipe 8 is adjusted to ensure the stability of the flow rate into the processing tower 1.

[0059] like Figure 13 As shown, the present invention also provides a multi-stage treatment method for plant extraction and processing wastewater, using the multi-stage treatment device for plant extraction and processing wastewater provided in this embodiment, including the following steps:

[0060] S1. Pretreatment: The plant extract processing waste liquid is treated by sedimentation, filtration, and pH adjustment to 4.5-5.5. The filtration can remove impurities such as plant fibers and suspended solids through a grid screen, reducing the risk of clogging of subsequent equipment. Dilute sulfuric acid is used to precisely control the waste liquid from the natural weak alkaline state to the weak acidic state (4.5-5.5), inhibiting the Maillard reaction of reducing sugars, avoiding the generation of melanin-like coking products in the high-temperature treatment zone, promoting the formation of soluble salts of calcium and magnesium ions, preventing the scaling of carbonates and oxalates, and obtaining the original plant extract processing waste liquid.

[0061] S2. Multi-stage treatment: The plant extraction and processing waste liquid is treated at least twice by a multi-stage treatment device to obtain alcohol solvents and de-alcoholized liquid. In this step, the position of the conical balance plate 26 inside the treatment tower 1 is automatically adjusted by air pressure to regulate the flow cross-section of the inlet 28, thereby reducing the flow pressure at the inlet 28 or allowing steam to accumulate in the lower layer of the tower plate assembly to ensure stable internal air pressure and improve treatment efficiency. The gas discharged from the top outlet pipe 12 during the first stage of treatment is then input into the condenser 9. At this time, in The pretreated plant extract processing waste liquid is fed into the condenser inlet 10. After exchanging heat with the plant extract processing waste liquid, the outgoing gas condenses to form the product liquid. The product liquid can flow into the next stage processing tower 1 through the product output pipe 13 to achieve multi-stage processing and improve product purity. After exchanging heat with the outgoing gas, the plant extract processing waste liquid flows into the secondary feed pipe 14 inside the processing tower 1 through the condenser outlet 11, thereby reducing heat loss. At the same time, the flow rate of the raw liquid feed pipe 8 is adjusted to ensure the stability of the flow rate into the processing tower 1.

[0062] S3. Membrane filtration: The 80-85℃ dehydrogenation solution is directly filtered through a ceramic microfiltration membrane, and then treated with a ceramic spiral wound nanofiltration membrane to separate low sugar and low salt permeate and sugar-salt mixture. The ceramic microfiltration membrane and ceramic spiral wound nanofiltration membrane can adapt to high-temperature treatment. The operating temperature is maintained by the residual heat of the dehydrogenation solution, which reduces the viscosity of the sugar solution and extends the membrane maintenance cycle. The sugar-salt mixture generated in this process can be directly utilized as a resource.

[0063] S4. Energy Recovery: The low-sugar, low-salt permeate is placed in the IC anaerobic reactor to produce biogas. The biogas is then burned to provide auxiliary heat energy for the reboiler 6, reducing treatment costs and improving energy utilization.

[0064] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0065] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A multi-stage treatment device for plant extraction and processing wastewater, comprising a pretreatment mechanism, a treatment tower (1), and a membrane filtration mechanism, characterized in that, Multiple sets of tray assemblies are arranged axially inside the processing tower body (1). Each set of tray assemblies includes, from top to bottom, a first guide shroud (17), an isolation sleeve (16), and a second guide shroud (18) arranged coaxially. The first guide shroud (17) has a bowl-shaped structure and an upper tower plate (33) is provided on its inner side. The upper tower plate (33) includes an upper air hole (3302) opened on the surface of the first guide shroud (17) and an upper separation ring (3301) fixed on the inner side of the first guide shroud (17). The upper separation ring (3301) extends and covers the upper air hole (3302) to guide the liquid phase away from the upper air hole (3302). The second guide shroud (18) has an inverted bowl-shaped structure and a lower tower plate (32) is provided on the outside. The lower tower plate (32) includes a lower gas hole (3202) opened on the surface of the second guide shroud (18) and a lower separation ring (3201) fixed on the outside of the second guide shroud (18). The lower separation ring (3201) extends and covers the lower gas hole (3202) to guide the liquid phase away from the lower gas hole (3202). The second guide shroud (18) is provided with a drain trough (24) at its edge. The drain trough (24) is provided with a flow guide plate (23) on both sides. A conical balance plate (26) is installed between the first guide shroud (17) and the second guide shroud (18) of the adjacent tower plate assembly. The conical balance plate (26) divides the gap between the two flow guide plates (23) into an air port (27) and a water port (28). The conical balance plate (26) can slide along the axial direction of the treatment tower (1) driven by the rising air pressure and gravity inside the treatment tower (1) to dynamically adjust the flow cross section of the water port (28). The isolation sleeve (16) is an hourglass-shaped structure, filled with heat-insulating cotton, and the surface of the isolation sleeve (16) is provided with a vibrating sheet (25). The vibrating sheet (25) vibrates under the impact of the rising airflow to disturb the steam flow field. The upper tower plate component (33) also includes an upper flow baffle ring (3303) installed on the upper end of the inner ring of the upper separation ring (3301), and an upper water distribution net (3304) is installed between the upper flow baffle ring (3303) and the first flow guide shroud (17). The lower tower plate component (32) also includes a lower flow-blocking ring (3203) installed on the outer ring of the lower separation ring (3201), and a lower water distribution net (3204) is installed between the lower flow-blocking ring (3203) and the second flow guide (18).

2. The multi-stage treatment device for plant extraction and processing wastewater according to claim 1, characterized in that: The first flow guide shroud (17) has a flow port (34) at its bottom. The processing tower body (1) has a bushing (29) inside. The bushing (29) is fixedly connected to the second flow guide shroud (18), and the gap between the bushing (29) and the flow port (34) forms a liquid phase downward channel.

3. The multi-stage treatment device for plant extraction and processing wastewater according to claim 2, characterized in that: A rotating shaft (21) is rotatably installed inside the bushing (29), and a fan blade (20) is fixed at the lower end of the rotating shaft (21). A reboiler (6) is provided at the lower outer side of the processing tower body (1). A steam output pipe (7) is installed at the output end of the reboiler (6). The outlet of the steam output pipe (7) is arranged tangentially along the processing tower body (1) to drive the fan blade (20) to rotate.

4. The multi-stage treatment device for plant extraction and processing wastewater according to claim 3, characterized in that: A diverter (19) is installed inside the processing tower (1) near the upper end. The diverter (19) is fixedly connected to the upper end of the rotating shaft (21), and both ends of the diverter (19) are conical structures with flow channels (22) arranged radially on its surface.

5. A multi-stage treatment device for plant extraction and processing wastewater according to claim 4, characterized in that, The conical balance disc (26) is made of high-temperature resistant lightweight plastic material, and a groove (31) is provided in the middle of the conical balance disc (26). A limiting guide rail (30) is provided on the outside of the bushing (29) and is slidably connected to the groove (31). The conical balance disc (26) slides to the lowest end of the limiting guide rail (30), and the minimum distance between the conical balance disc (26) and the lower first guide shield (17) is 0.5cm.

6. A multi-stage treatment device for plant extraction and processing wastewater according to claim 5, characterized in that, Also includes: Baffle (15) is fixed to the upper part of the inside of the processing tower body (1); A condenser (9) is located outside the processing tower (1). The condenser (9) is used to condense the distilled gas inside the processing tower (1). Its refrigerant is the pretreated plant extract processing waste liquid. Its refrigerant output end extends to the upper part of the processing tower (1).

7. A multi-stage treatment device for plant extraction and processing wastewater according to claim 6, characterized in that: The processing tower body (1) is also equipped with a raw liquid feed pipe (8) near the upper end, and the processing tower body (1) is equipped with a tower bottom discharge pipe (3) at the lower end. The processing tower body (1) is also equipped with an overflow pipe (4), which is located between the steam output pipe (7) and the tower bottom discharge pipe (3).

8. A multi-stage treatment method for plant extraction and processing wastewater, characterized in that, The multi-stage treatment device for plant extraction and processing wastewater according to any one of claims 1-7 includes the following steps: S1. Pretreatment: The plant extract processing waste liquid is treated by sedimentation, filtration, and pH adjustment to 4.5-5.5 to obtain the original plant extract processing waste liquid; S2. Multi-stage treatment: The raw liquid of plant extraction and processing waste liquid is treated at least twice by a multi-stage treatment device to obtain alcohol solvent and de-alcoholized liquid. S3. Membrane filtration: The alcohol-dehydrogenated liquid at 80-85℃ is directly filtered through a ceramic microfiltration membrane, and then treated with a ceramic spiral wound nanofiltration membrane to separate low-sugar, low-salt permeate and a sugar-salt mixture. S4, Energy Recovery: Low-sugar and low-salt permeate is placed in an IC anaerobic reactor to produce biogas, which is then burned to provide auxiliary heat energy for the reboiler (6).

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