A system for treating solvent-containing wastewater

Abstract

The application provides a solvent-containing wastewater treatment system, and belongs to the technical field of wastewater treatment. The solvent-containing wastewater treatment system comprises an evaporator, a separation tank, a rectifying tower and a phase separation tank. The separation tank has a first chamber and a second chamber. Wastewater enters the evaporator. The gas flowing out of the first gas phase outlet in the evaporator enters the rectifying tower. The liquid flowing out of the first liquid phase outlet enters the first chamber. The liquid in the separation tank evaporates and enters the rectifying tower through the second gas phase outlet. The liquid flowing out of the rectifying tower enters the second chamber through the second liquid phase outlet. The liquid in the second chamber flows back to the evaporator. The gas generated by the rectifying tower enters the phase separation tank through the third gas phase outlet. The phase separation tank is used for separating water from the condensed gas and flowing back to the top of the rectifying tower to form a reusable light phase.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, and specifically relates to a treatment system for solvent-containing wastewater. Background Technology

[0002] In the pharmaceutical industry, solvents are widely used in various processes, such as reactions and extractions. Common solvents include butyl acetate, butanol, dichloromethane, methanol, toluene, and acetone. These solvents are often consumed in large quantities, and recycling and reuse are important aspects of this industry in order to reduce production costs and pollutant emissions.

[0003] Solvent recovery processes include extractive distillation, azeotropic distillation, conventional distillation, extraction, reaction, and membrane filtration. Based on the physical properties of the waste solvent or solvent-wastewater system, a suitable process is selected. For example, in a ternary azeotropic system of vinyl acetate-butanol-water, azeotropic distillation is a more reasonable method for separation, while conventional distillation is sufficient for methanol-water or acetone-water systems. Solvent recovery processes must meet requirements for wastewater discharge standards, solvent recovery rate, and purity, while also controlling energy consumption.

[0004] Waste solvents often have complex compositions and contain many trace impurities, such as acids, alkalis, heat-sensitive substances, or particulate matter. These impurities can sometimes have a significant impact on the recovery process, easily causing problems such as corrosion, blockage, discoloration, and reduced heat exchanger efficiency.

[0005] Common recycling methods mainly include atmospheric distillation and vacuum distillation. These processes can only handle relatively clean waste solvents. For materials with complex composition, containing solids or viscous substances, problems such as tower blockage, inability to operate normally, and substandard products are likely to occur. Summary of the Invention

[0006] This invention provides a treatment system for solvent-containing wastewater, aiming to solve the technical problems of easy tower blockage, inability to operate normally, and substandard products in existing solvent recovery processes.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is: to provide a treatment system for solvent-containing wastewater, comprising: The evaporator has a first gas phase outlet and a first liquid phase outlet; The separator has a first chamber, a second chamber, and a second gas phase outlet. The first chamber is connected to the first liquid phase outlet, and the liquid in the second chamber is used to flow back to the evaporator. A distillation column has a second liquid phase outlet and a third gas phase outlet, the distillation column being connected to the first gas phase outlet and the second gas phase outlet, and the second liquid phase outlet being connected to the second chamber; The phase separation tank is connected to the third gas phase outlet and is used to separate the aqueous phase and return it to the top of the distillation column. Wastewater enters the evaporator, the gas flowing out of the first gas phase outlet of the evaporator enters the distillation column, the liquid flowing out of the first liquid phase outlet enters the first chamber, the liquid in the separation tank evaporates and enters the distillation column through the second gas phase outlet, the liquid flowing out of the distillation column enters the second chamber through the second liquid phase outlet, the liquid in the second chamber flows back to the evaporator, the gas generated by the distillation column enters the phase separation tank through the third gas phase outlet, the phase separation tank is used to condense the gas and separate water, which flows back to the top of the distillation column to form a reusable light phase.

[0008] In one possible implementation, the separation tank includes: Tank body; A partition is fixed inside the tank, and the first chamber and the second chamber are formed on opposite sides of the partition. The top of the partition is spaced from the inner wall of the tank so that the liquid phase in the first chamber can overflow into the second chamber. A steam drum is located at the top of the tank, and the steam outlet of the steam drum forms the second gas phase outlet.

[0009] In one possible implementation, the bottom of the tank is provided with a first external drain pipe that communicates with the first chamber.

[0010] In one possible implementation, the evaporator is a scraped falling film evaporator.

[0011] In one possible implementation, a condenser is also provided between the third gas phase outlet and the phase separation tank.

[0012] In one possible implementation, the phase separation tank has a fourth gas phase outlet, and the solvent-containing wastewater treatment system further includes a vacuum pump connected to the fourth gas phase outlet.

[0013] In one possible implementation, the bottom of the distillation column is provided with a second exhaust pipe.

[0014] In one possible implementation, a liquid transmitter is provided on the outside of the distillation column, and both the inlet and outlet sides of the liquid transmitter are connected to the distillation column.

[0015] In one possible implementation, a power pump is provided between the second chamber and the evaporator, and between the phase separation tank and the distillation column.

[0016] In one possible implementation, the distillation column is also equipped with a temperature transmitter and a pressure transmitter.

[0017] Compared with the prior art, the solvent-containing wastewater treatment system of this application utilizes a separator to enrich particulate matter and penicillin metabolites in the first chamber. After a period of enrichment, the system can be cleaned to prevent them from entering the distillation column and thus preventing tray blockage. The evaporator vaporizes a large amount of solvent components in the wastewater, effectively inhibiting the decomposition and discoloration of penicillin metabolites. The higher the vaporization rate and the larger the flow rate of the evaporator, the lower the butyl acetate content in the distillation column wastewater. However, the process operation conditions and energy consumption of the evaporator must be considered. The entire treatment system can operate intermittently (the evaporator treats a certain amount of wastewater before proceeding to the next treatment) or continuously (the wastewater is continuously treated by the evaporator), meeting different production needs. It also features non-destructive properties for heat-sensitive components, low energy consumption, and high solvent recovery rate. Attached Figure Description

[0018] Figure 1 A process flow diagram of a solvent-containing wastewater treatment system provided in an embodiment of the present invention.

[0019] Explanation of reference numerals in the attached figures: 10 - Evaporator; 11 - First gas phase outlet; 12 - First liquid phase outlet; 20-Separation tank; 21-Tank body; 22-Baffle plate; 23-Steam drum; 24-First chamber; 25-Second chamber; 26-Second gas phase outlet; 27-First exhaust pipe; 30 - Distillation column; 31 - Second liquid phase outlet; 32 - Third gas phase outlet; 33 - Second external discharge pipe; 34 - Liquid transmitter; 35 - Temperature transmitter; 36 - Pressure transmitter; 40 - Phase separation tank; 41 - Fourth gas phase outlet; 50-Condenser; 60 - Vacuum pump; 70 - Power Pump. Detailed Implementation

[0020] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. The following description of at least one exemplary embodiment is actually illustrative only and is in no way intended to limit this application or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0022] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0023] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0024] In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0025] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways, and the spatial relative descriptions used herein will be interpreted accordingly.

[0026] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0027] Please refer to the following: Figure 1 The present invention provides a treatment system for solvent-containing wastewater. The treatment system includes an evaporator 10, a separation tank 20, a distillation column 30, and a phase separation tank 40. The evaporator 10 has a first gas phase outlet 11 and a first liquid phase outlet 12. The separation tank 20 has a first chamber 24, a second chamber 25, and a second gas phase outlet 26. The first chamber 24 is connected to the first liquid phase outlet 12, and the liquid in the second chamber 25 is used to return to the evaporator 10. The distillation column 30 has a second liquid phase outlet 31 and a third gas phase outlet 32. The distillation column 30 is connected to the first gas phase outlet 11 and the second gas phase outlet 26, and the second liquid phase outlet 31 is connected to the second chamber 25. The phase separation tank 40 is connected to the third gas phase outlet 32 ​​and is used to separate the aqueous phase, which flows back to the top of the distillation column 30. Wastewater enters evaporator 10. Gas flowing out of the first gas phase outlet 11 of evaporator 10 enters distillation column 30. Liquid flowing out of the first liquid phase outlet 12 enters first chamber 24. Liquid in separator 20 evaporates and enters distillation column 30 through second gas phase outlet 26. Liquid flowing out of distillation column 30 enters second chamber 25 through second liquid phase outlet 31. Liquid in second chamber 25 flows back to evaporator 10. Gas generated in distillation column 30 enters phase separation tank 40 through third gas phase outlet 32. Phase separation tank 40 is used to condense the gas, separate water, and return it to the top of distillation column 30 to form a reusable light phase.

[0028] The specific usage process of the solvent-containing wastewater treatment system provided in this embodiment is illustrated below: Wastewater containing small amounts of butyl acetate, penicillin metabolites, and particulate matter is mixed into the inlet pipe of evaporator 10 from the tank area. After being heated to 40-45°C, the liquid flows out from the first liquid phase outlet 12 and enters the first chamber 24 of the separator 20. The gas generated by evaporation in evaporator 10 (passing through the first gas phase outlet 11) enters the distillation column 30. During this process, particulate matter and penicillin metabolites do not vaporize and enter the distillation column 30, achieving preliminary separation. After the liquid (passing through the first liquid phase outlet 12) enters the first chamber 24 of the separator 20, the particulate matter settles and remains in the first chamber 24. As the liquid gradually enters, the particulate matter gradually settles and remains in the first chamber 24. The liquid gradually overflows into the second chamber 25, where it mixes with the liquid from the distillation column 30 (flowing out from the second liquid phase outlet 31). It then returns to the evaporator 10 to vaporize the butyl acetate and water azeotrope and re-enter the distillation column 30. The liquid inside the separator 20 vaporizes (through the second gas phase outlet 26) and enters the distillation column 30. The distillation column 30 performs distillation to produce gas, which (flowing out from the third gas phase outlet 32) is condensed and enters the phase separation tank 40. The phase separation tank 40 separates the water and gas, and the water produced by the separation is sent back to the top of the distillation column 30. The light phase at the top of the column, with a butyl acetate content as high as 98%, is sent out for reuse.

[0029] Compared with existing technologies, the solvent-containing wastewater treatment system of this application utilizes a separator 20 to enrich particulate matter and penicillin metabolites in the first chamber 24. After a period of enrichment, the system can be cleaned to prevent them from entering the distillation column 30 and thus prevent tray blockage. The evaporator 10 vaporizes a large amount of solvent components in the wastewater, effectively inhibiting the decomposition and discoloration of penicillin metabolites. The higher the vaporization rate and flow rate of the evaporator 10, the lower the butyl acetate content in the wastewater of the distillation column 30. However, the process operation conditions and energy consumption of the evaporator 10 must be considered. The entire treatment system can operate intermittently (the evaporator 10 treats a certain amount of wastewater before proceeding to the next treatment) or continuously (the wastewater is continuously treated by the evaporator 10), meeting different production needs. It also features non-destructive properties for heat-sensitive components, low energy consumption, and high solvent recovery rate.

[0030] It should be noted that: Evaporator 10 is a scraped-film falling film evaporator, which mainly includes a heating chamber, a scraper device, and a separation chamber. The heating chamber is composed of a jacket or tubes, etc., providing the heat required for evaporation. The heat medium (hot water at 50°C can be used, which is inexpensive, will not cause penicillin metabolites to decompose and change color, and the heavy phase in the wastewater will not enter the distillation column 30) circulates in the heating chamber to heat the material inside the tubes. The scraper device consists of a rotating shaft and scrapers. The scrapers are tightly attached to the inner wall of the heating tubes by springs or other means. When the rotating shaft rotates, the scrapers rotate accordingly, forming a uniform liquid film on the inner wall of the tubes. The separation chamber is located below the heating chamber and is used for gas-liquid separation, separating the secondary vapor generated by evaporation from the concentrated liquid phase.

[0031] In some embodiments, the separation tank 20 may be adopted as follows: Figure 1 The structure shown. See also Figure 1 The separator 20 includes a tank body 21, a partition 22, and a steam drum 23. The partition 22 is fixed inside the tank body 21. The opposite sides of the partition 22 form a first chamber 24 and a second chamber 25. The top of the partition 22 is spaced from the inner wall of the tank body 21 so that the liquid phase in the first chamber 24 can overflow into the second chamber 25. The steam drum 23 is located on the top of the tank body 21, and the steam outlet of the steam drum 23 forms a second gas phase outlet 26.

[0032] The baffle 22 divides the space inside the tank 21 into a first chamber 24 and a second chamber 25. Since the top of the baffle 22 is separated from the inner wall of the tank 21, the liquid in the first chamber 24 can overflow into the second chamber 25. No particulate matter will appear in the second chamber 25. Since the second chamber 25 is connected to the distillation column 30 and needs to receive liquid from the distillation column 30, the absence of particulate matter in the second chamber 25 means that no particulate matter will enter the distillation column 30 due to backflow or other factors, thus avoiding column blockage.

[0033] The vapor drum 23 includes a main container and internal auxiliary devices (such as a cyclone separator, a baffle separator, and a perforated plate). The main container is fixed to the top of the tank 21 and can be positioned directly above the second chamber 25. Since the second chamber 25 is entirely filled with liquid, the vapor drum 23 will vaporize the liquid to form gas during operation. However, since the first chamber 24 and the second chamber 25 are connected, vaporization will also occur if there is liquid in the first chamber 24. By setting up the vapor drum 23, the gas phase can be stably collected, preventing the gas phase from carrying liquid impurities into the distillation column 30 and improving the separation efficiency of the distillation column 30; at the same time, it simplifies the structure of the separation tank 20 and reduces equipment complexity.

[0034] In some embodiments, an improved implementation of the separation tank 20 may employ, as follows: Figure 1 The structure shown. See also Figure 1The bottom of the tank 21 is provided with a first drain pipe 27 that communicates with the first chamber 24. The first drain pipe 27 can be set at the bottom of the first chamber 24. Since the first chamber 24 will periodically accumulate sediment, when the sediment exceeds the height of the partition 22, it will enter the second chamber 25, causing the distillation column 30 to be blocked. Therefore, the first drain pipe 27 is set to periodically drain the sediment in the first chamber 24, ensuring the long-term stable operation of the separator 20. Compared with directly disassembling the separator 20 to clean the first chamber 24, the technical solution of this embodiment can reduce the frequency of equipment maintenance and production interruption time.

[0035] To facilitate the discharge of sediment, a valve can be installed on the first discharge pipe 27. The size of the first discharge pipe 27 can be relatively large to facilitate the discharge of sediment. The valve can be opened when cleaning is required.

[0036] In some embodiments, an improved implementation of the above-described solvent-containing wastewater treatment system can employ, as follows: Figure 1 The structure shown. See also Figure 1 A condenser 50 is also provided between the third gas phase outlet 32 ​​and the phase separation tank 40.

[0037] It should be explained that the distillation column 30 includes the column body, the foot pedal + downcomer + overflow weir located inside the column body, the reboiler located at the bottom of the column, and the condenser 50 located at the top of the column. The distillation column 30 utilizes the different volatility of the components in the mixture (easily volatile components: lower boiling point, easier to vaporize; less volatile components: higher boiling point, more difficult to vaporize) to gradually achieve component separation through the "countercurrent flow + multiple mass transfers" of the gas and liquid phases inside the column.

[0038] Directly discharging the gas from the top of distillation column 30 would waste energy. By setting a third gas outlet 32, the gas at this point is condensed (to 30°C) and then enters the phase separator 40. The phase separator 40 can separate the gas and water, and then discharge the water back to the top of the column.

[0039] The technical solution of this embodiment condenses the gas flowing out of the distillation column 30 into liquid, avoiding incomplete separation caused by the coexistence of gas and liquid in the phase separation tank 40, and improving the phase separation efficiency; the temperature of the material after condensation is reduced, which reduces the gas phase loss in the phase separation tank 40, improves the solvent recovery efficiency, and reduces the load on the phase separation tank 40.

[0040] It should be noted that the phase separation tank 40 includes a shell, a feeding device, a reinforced separation structure (corrugated plates, stacked packing, etc.), and a discharge device. By utilizing the density difference of immiscible fluids, the dispersed phase (small amount of phase) settles or floats to the continuous phase (large amount of phase) under the action of gravity, ultimately forming a clear stratified interface, and then completing the separation through precise discharge.

[0041] The phase separation tank 40 has a similar structure to the separation tank 20, with two internal chambers (hereinafter referred to as chamber a and chamber b). Gas from the distillation column 30 is condensed and enters chamber a. Chamber a has an enhanced separation structure, where liquid settles and separates to obtain water. Excess water overflows into chamber b. A pipe is provided at the bottom of chamber a, allowing the water at the bottom of chamber a to flow back to the top of the distillation column 30, thus obtaining a light phase with a butyl acetate content as high as 98%. Chamber b mainly contains water overflowing from chamber a and gas at the top of the water. The top of chamber b has an outlet connected to the vacuum pump 60. The vacuum pump 60 keeps the entire system under vacuum. An external drain pipe can also be installed at the bottom of chamber b to periodically drain the water in chamber b, preventing deterioration due to long-term storage. Draining water from chamber b also ensures a balance between the inflow and outflow in the phase separation tank 40, maintaining a vacuum environment.

[0042] Specifically, considering the requirements and feasibility of the phase separation tank 40 during operation, pressure gauges, safety valves, temperature sensors, etc. can also be installed on the phase separation tank 40.

[0043] As an alternative implementation, without the condenser 50, ice or other refrigerant can be placed around the outer periphery of the gas phase pipeline connecting the distillation column 30 and the phase separation tank 40 to achieve preliminary condensation of the gas phase inside the pipeline during the flow process. This structure has a lower cost and is easy to arrange.

[0044] In some embodiments, an improved implementation of the phase separation tank 40 described above can adopt the following approach: Figure 1 The structure shown. See also Figure 1 The phase separation tank 40 has a fourth gas phase outlet 41, and the treatment system for solvent-containing wastewater also includes a vacuum pump 60 connected to the fourth gas phase outlet 41. The vacuum pump 60 achieves a vacuum throughout the system, ensuring a vacuum degree of 20 kPa. Under vacuum conditions, the azeotropic temperature of butyl acetate-water drops from over 90°C at atmospheric pressure to 40-45°C, further reducing the heating temperature of the evaporator 10 and preventing the decomposition of heat-sensitive substances. The lower boiling point makes the solvent more easily vaporized, increasing the gas phase yield of the evaporator 10 and enhancing the processing capacity of the distillation column 30. Simultaneously, it reduces the accumulation of non-condensable gases within the system, preventing a decrease in heat transfer efficiency.

[0045] In some embodiments, an improved implementation of the distillation column 30 described above may employ, as follows: Figure 1 The structure shown. See also Figure 1The bottom of the distillation column 30 is equipped with a second drain pipe 33. Since the entire system is under vacuum, the inflow and outflow of the distillation column 30 need to be kept balanced in order to maintain the vacuum environment. After distillation separation, the low solvent content wastewater (butyl acetate ≤100ppm) remaining at the bottom of the column is discharged from the system through the second drain pipe 33. This not only allows for the timely discharge of purified wastewater, preventing accumulation at the bottom of the column and avoiding abnormal liquid level in the distillation column 30, thus ensuring stable distillation operation, but also maintains the vacuum environment of the system.

[0046] It should be noted that the butyl acetate content in the wastewater is as low as 100 ppm, meeting environmental emission standards, while avoiding solvent waste at the bottom of the column, thus balancing environmental protection and economy. An external discharge pump and valve can be installed on the second discharge pipe 33. When discharge is required, the valve and external discharge pump are opened, and the external discharge pump draws the wastewater from the bottom of the distillation column 30 for external discharge.

[0047] Specifically, a liquid transmitter 34 is installed on the outside of the distillation column 30, with both the inlet and outlet sides of the liquid transmitter 34 connected to the distillation column 30. The liquid transmitter 34 detects the pressure difference or liquid level height of the liquid phase within the column, providing real-time feedback on changes in liquid volume / level within the distillation column 30. This signal is transmitted to the control system, enabling real-time monitoring of the liquid level within the distillation column 30, ensuring continuous and stable system operation. Furthermore, based on the detection value of the liquid level transmitter, the inlet and outlet rates of the preceding and following stages of the distillation column 30 can be adjusted to prevent a decrease in solvent recovery rate due to abnormal liquid levels.

[0048] The liquid transmitter 34 is equipped with a switching valve on both the inlet and outlet sides. The operating state of the liquid transmitter 34 can be switched (e.g., open or closed) by adjusting the switching valve.

[0049] The distillation column 30 is also equipped with a temperature transmitter 35 and a pressure transmitter 36. The temperature transmitter 35 monitors the temperature of different trays in the distillation column 30 in real time (such as the top, middle, and bottom trays), reflecting the separation progress of the solvent and water. The pressure transmitter 36 monitors the pressure in the distillation column 30 in real time, working with the vacuum pump 60 to maintain a stable system vacuum. Both transmitters transmit their signals to the control system for adjusting parameters such as heating capacity, vacuum pump 60 pumping speed, and reflux ratio. This structure combines parameter visualization with precise control, avoiding product defects or equipment failures caused by abnormal temperature or pressure. Through real-time parameter adjustment, energy consumption can be reduced while ensuring solvent recovery rate and light phase purity, balancing technical performance and economic efficiency.

[0050] To facilitate the reception of the detection values ​​and operating status of the liquid transmitter 34, temperature transmitter 35, and pressure transmitter 36, a PLC system can be set up. The liquid transmitter 34, temperature transmitter 35, and pressure transmitter 36 can be connected to the PLC system via electrical wiring or communication connection. Thus, when the distillation column 30 is operating, the detection values ​​and operating status (e.g., whether they are turned on) of the liquid transmitter 34, temperature transmitter 35, and pressure transmitter 36 can be observed through the PLC system. Furthermore, the PLC system can also control the liquid transmitter 34, temperature transmitter 35, and pressure transmitter 36, for example, by setting standard values. When the value detected by any transmitter exceeds the standard value, the PLC system will issue an alarm (via an audible and visual alarm) to promptly remind operators to check and ensure the safety and accuracy of the entire process.

[0051] In some embodiments, an improved implementation of the above-described solvent-containing wastewater treatment system can employ, as follows: Figure 1 The structure shown. See also Figure 1 A power pump 70 is installed between the second chamber 25 and the evaporator 10, and between the phase separation tank 40 and the distillation column 30. The liquid in the second chamber 25 is pressurized by the power pump 70 and flows back to the evaporator 10 to overcome pipeline resistance, ensuring smooth liquid phase circulation; the aqueous phase in the phase separation tank 40 is pressurized by the power pump 70 and stably delivered to the top of the distillation column 30 to maintain the reflux flow rate required for distillation.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A treatment system for solvent-containing wastewater, characterized in that, include: The evaporator has a first gas phase outlet and a first liquid phase outlet; The separator has a first chamber, a second chamber, and a second gas phase outlet. The first chamber is connected to the first liquid phase outlet, and the liquid in the second chamber is used to flow back to the evaporator. A distillation column has a second liquid phase outlet and a third gas phase outlet, the distillation column being connected to the first gas phase outlet and the second gas phase outlet, and the second liquid phase outlet being connected to the second chamber; The phase separation tank is connected to the third gas phase outlet and is used to separate the aqueous phase and return it to the top of the distillation column. Wastewater enters the evaporator, the gas flowing out of the first gas phase outlet of the evaporator enters the distillation column, the liquid flowing out of the first liquid phase outlet enters the first chamber, the liquid in the separation tank evaporates and enters the distillation column through the second gas phase outlet, the liquid flowing out of the distillation column enters the second chamber through the second liquid phase outlet, the liquid in the second chamber flows back to the evaporator, the gas generated by the distillation column enters the phase separation tank through the third gas phase outlet, the phase separation tank is used to condense the gas and separate water, which flows back to the top of the distillation column to form a reusable light phase; The separation tank includes: Tank body; A partition is fixed inside the tank, and the first chamber and the second chamber are formed on opposite sides of the partition. The top of the partition is spaced from the inner wall of the tank so that the liquid phase in the first chamber can overflow into the second chamber. A steam drum is located at the top of the tank, and the steam outlet of the steam drum forms the second gas phase outlet.

2. The solvent-containing wastewater treatment system as described in claim 1, characterized in that, The bottom of the tank is provided with a first external drain pipe that communicates with the first chamber.

3. The solvent-containing wastewater treatment system as described in claim 1, characterized in that, The evaporator is a scraped falling film evaporator.

4. The solvent-containing wastewater treatment system as described in claim 1, characterized in that, A condenser is also provided between the third gas phase outlet and the phase separation tank.

5. The solvent-containing wastewater treatment system as described in claim 1, characterized in that, The phase separation tank has a fourth gas phase outlet, and the treatment system for solvent-containing wastewater also includes a vacuum pump connected to the fourth gas phase outlet.

6. The solvent-containing wastewater treatment system as described in claim 1, characterized in that, The bottom of the distillation column is equipped with a second external discharge pipe.

7. The solvent-containing wastewater treatment system as described in claim 6, characterized in that, A liquid transmitter is provided on the outside of the distillation column, and both the inlet and outlet sides of the liquid transmitter are connected to the distillation column.

8. The solvent-containing wastewater treatment system as described in claim 1, characterized in that, A power pump is provided between the second chamber and the evaporator, and between the phase separation tank and the distillation column.

9. The solvent-containing wastewater treatment system as described in claim 1, characterized in that, The distillation column is also equipped with a temperature transmitter and a pressure transmitter.

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